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DEPARTMENT OF THE NAVAL SERVICE

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CANADIAN FISHERIES EXPEDITION, 1914-1915

nvestigations in the Gulf of St. Lawrence
and Atlantic Waters of Canada

UNDER THE DIRECTION OF

DR. JOHAN HJORT,

Head of the Expedition

Director of Fisheries for Norway.

OTTAWA

J. DE LABROQUERUE TACH6

PRINTER TO THE KING'S MOST EXCELLENT MA.TESTT

6551— A

LIST OF ERKATA TO BE NOTED BY THE READER.

P, 28, Fig. 20. Merluccius not Merlucius.
P. 30, Fig. 21. Mallotus not Malotus.
P. 32, Fig. 22. Mallotus not Malotus.

P. 118, Fig. 29. The second figure 6 at the bottom of the figure should be 8.

Coloured Plate 1 (Sandstrom's Report). 83 not 33 between 67 and 31 NE. of Station
VIII.

" " 2 (Sandstrom's Eeport). The figure 4 below V is reversed in error.

" " 3 (Sandstrom's Report). In the explanation X — XX should be

XIII — XX, and the small triangular area close to 65 should
be yellow not white. Also the figures 82-88 should be 83-89 and
79-81 consecutively.

" " 4 (Sandstrom's Report). Omit minus sign ( — ) in legend. It should

be <0°C not <— 0'°C.

" " 4 (Sandstrom's Report). The triangular space with V in the centre

should be white, not coloured red.

" " 5 (Sandstrom's Report). Midway between XVIII pi.d XIX the figures

should be 89 not 79.

DEPARTMENT OF THE NAVAL SERVICE.

CANADIAN FISHERIES EXPEDITION, 1914-1915, IN THE GULF OF ST.
LAWRENCE AND ATLANTIC^ WATERS OF CANADA,

Under the Direction of Dr. Johan TJjort, Director of Fhheries for Norway.

Scientific results embodied in nine memoirs as follows :—

Johan Hjort: Introduction to the Canadian Fisheries Expedition, 1914-1915.

Alf. Dannevig: Canadian Fish-Eggs and Larvae.

Einar Lea: Age and Growth of the Herring in Canadian "Waters.

A. G. Huntsman: Growth of the Young Herring (so-called sardines) of the Bay of
Fundy.

Arthur Willey: Eeport on the Copepoda obtained in the Gulf of St. Lawrence and
adjacent waters, 1915.

fT. W. Sandstrom: The Hydrodynamics of the Canadian Atlantic Waters.

Paul Bjerkan : Eesults of the Hydrographical Observations made by Dr. Johan Hjort
in the Canadian Atlantic Waters during the year 1915.

A. G. Huntsman: Some Quantitative and Qualitative Plankton Studies of the Eastern
Canadian Plankton.

1. Introduction.

2. Quantity of Plankton.

3. A Special Study of the Canadian Chsetognaths, their Distribution, etc., in

the Waters of the Eastern Coast of Canada.

H. H. Gran : Quantitative Investigations as to Phytoplankton and Pelagic Protozoa
in the Gulf of St. Lawrence and outside the same.

0551 — Aj

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. L. I ■ R A R ^ , ^

PREFACE.

J3y Professor Edward E. Prince, LL.D., Dominion Commissioner of Fi^herie»
and Chairman of the Biological Board of Canada.

The series of reports on the results of the Canadian Fisheries Expedition, 1914-15,
witli the important introductory memoir by Dr. Iljort, Director of Fisheries under
the Government of Norway, and head of the expedition, are weighty contributions to
our knowledge of fish-life in the sea. They inform us, also, as to the complex condi-
tions of marine life generally in our Atlantic waters, and a fe^v preliminary words
:5eem necessary in explanation of the origin, character, and scope of the expedition.
About ten years ago the Biological Board of Canada, of which I am chairman, decided
to ask Dr. Hjort if he could take charge of a comprehensive fishery investigation in
Canadian waters on the lines of the researches which, under his direction, had proved
so beneficial to the fisheries of Norway. In spite of the fact that the great cod and
other fisheries off our Atlantic coast had been carried on for centuries, it was felt
that there were doubtless hidden possibilities of development and expansion that
awaited only a basis of accurate knowledge to turn them to account. Certain urgent
problems affecting the herring resources of the gulf of St. Lawrence and the Atlantic
coast adjacent seemed to call for adequate scientific investigation. After some corre-
spondence with Dr. Hjort, carried on by myself and by Professor McBride (then of
McGill University, and a member of the Biological Board), the matter was allowed to
remain in abeyance. Dr. Hjort could not at that time visit Canada, though he sug-
gested the name of an able young Norwegian scientist who might undertake the work.
The proposal was revived by the Biological Board five years ago, with the result that
after much correspondence. Dr. Hjort came to Canada, and arrangements for the
expedition were completed in Ottawa, after conferences between the Deputy ^linister
(Mr. Desbarats), the Biological Board, and Dr. Hjort.

As the expenditure involved in carrying out a well-planned df cp-sea investigation
was too considerable to be readily met by the Biological Board, the Deputy Minister
of the Naval Service cordially agreed to an arrangement whereby the department
would provide the amount necessary. Dr. Hjort and I met in conference a number
of times and, as a result, a plan of work was outlined, which is summarized in the
Introductory Report. The plan embraced the necessary physical, hydrographical,
chemical, and biological researches, including collection of water samples, etc., and
the determination of the plankton collections, distribution and varied abundance of
the young fry, as well as the eggs of the cod, haddock, flat-fishos, and other species,
in addition to the thorough study of the varieties, distribution, migrations, and breed-
ing of the herring. The survey, in short, was to be as complete as possible in order to
afford a basis for the future development of the fishing industries.

Eight years ago Dr. Hjort had carried on investigations in Newfoundland v.aterp.
in conjunction with the late Sir John Murray, on the well-known cruise of the Nor-
wegian Government steamer Michael Sars. The Canadian investigations now planned
would, it was thought, advance some aspects of the important results achieved by
Dr. Hjort and Sir John ^Murray. They certainly show, as demonstrated in the Pre-
liminary Report on the "Natural History of the Herring. 1014," by Dr. Hjort,
published by the Naval Service Department in 1915. in what a unique degree the
Atlantic waters of Canada, especially the gulf of St. Lawrence, a thorough scientific
investigation can aid in the solution of important fishery problems so exhaustively
studied in Norway. These problems centre round the relation between the distribu-
tion and life-cycles of fishes, and other organisms, and the prevailing environments

vi PREFACE

obtaining in successive seasons of the year, the physical, chemical, biological, and
other conditions, which so profoundly affect animal and plant life in the sea.

Dr. Hjort has succinctly summarized in his Introductory Keport his own main
results, and the results obtained by the scientific staff working under him, in connec-
■ tion with the expedition.

The herring resources of the Atlantic coastal waters of Canada and of the gulf
of St. Lawrence offer a field for enormous commercial development, and Dr. Hjort
gave primary attention to the study of the Canadian herring.

As the Preliminary Report on the various types of Canadian herring described
by Dr. Hjort was published three years ago, it is not necessary to repeat its main
points here, and Mr. Einar Lea's further and more elaborate detailed results must be
studied in his report now presented; but it may be pointed out that, on the whole,
four very different groups of herring may be distinguished, viz. : —

(1) The Newfoundland type (with the remarkable exception of the St. George
Bay herring), which grows slowly during the first summer, but from the third summer
on grows at a rapid rate. The samples studied ranged from four to twenty years in
age, and the age-group of 1904 was dominant, recalling Dr. Hjort's discovery of a
dominant age-group in JSTorway — a single year-class maintaining a dominant position
in successive season's catches for several years. The typical Newfoundland herring
in growth and age composition of the schools form a group distinct and apart, as
demonstrated by all the samples studied.

(2) The second type are formed by the herring off cape Gaspe, Magdalen islands,
and Northumberland straits, roughly embracing the west and northwest waters of the
gulf of St. Lawrence, which grow rapidly during the first summer, and slowly in later
years, and are thus smaller later on than Newfoundland herring of the same age.
The 1903 and 1907 year-classes dominated.

(3) A third type from the Cape Breton (Atlantic) coast, from North Sydney
south, which have a moderate first-summer's growth, but a more rapid growth from
the third summer on. The divergent type from bay St. George, Newfoundland, belongs
to this group. The dominant age-group is that of 1903.

(4) A fourth type from Chedabucto bay and southwest along the Nova Scotia
shore, which grows well during the whole of its first five or six years, and outdistances
all the other types of herring. The 1911 year-class was found to prevail, while in the
large, older herring from Nova Scotia, the 1908 year-class dominated, and in the
Halifax and Lockport samples the 1908, 1910, and 1911 year-classes were best repre-
sented.

Mr. Einar Lea makes the important observation in his report that the samples of
herring which resembled each other in age-composition, also exhibited great resem-
blance as regards growth, hence the types signalized would appear to be valid and
unquestionable, though more extended researches are urgent to fvilly confirm these
results.

The special investigations upon the herring yielded conclusions so interesting
that it seemed necessary to extend the studies in hand to other species, and to eluci-
date faunistic conditions generally in all the Gulf and Atlantic waters embraced in
the scheme.

Problems as to the influence of the earth's rotation, the effects of the annual
melting of the great fields of ice, the features of temperature, salinity, specific gravity,
etc., of the sea water, and other matters vital to the vertebrate and invertebrate life,
and especially fish-life, off our Atlantic coast, were included.

Professor Gran's masterly plankton studies show that in the gulf of St. Lawrence
there is a plentitude of minute floating plants of northern types, whose development
each season appears to be annually much later than in the northern European waters.
The prevalence of an Arctic temperature for so large a part of the jeav is the explana-
tion.

PREFACE vii

On the spawning, the eggs, and the young stages of food- and other fishes, import-
ant observations were made. Mr. Danneviig's report on the material obtained is
exceedingly interesting. Thirty-six species were determined, which belong to twenty
families, the cod being most important, and its eggs and larvae occurred during a long
period, May to August. Haddock were more rare, one egg only being secured in the
gulf of St. Lawrence. Nor were mackerel egg numerous, while very few flat-fish eggs,
or young, were found, excepting the Canadian Plaice.

The eggs and young of fishes and other animal forms constitute an important
part of the plankton, but the scarcity of these eggs and young is a striking feature.
Over the northern portions of the gulf, there occurred, in May and June, eggs of cod
and other gadoids, also flatfishes, and in a marked degree the eggs of the Canadian
plaice {Rippoglossoides, or Drepanopsetta) , with a few larval fish of Arctic types such
as the northern wolf -fish (Anarrichas latifrons), capelin (Mallotus), and others.
Mackerel eggs were taken in Cabot straits, and considerable quantities of Norway
haddock or rose fish (Sehastes) over the deep (Laurentian) channel leading from the
gulf into the open ocean. Expectations of greater quantities of floating fish eggs, in
the later summer cruises, were disappointed. Cod eggs occurred, and a very small
number of young fish, while northern forms such as Mallotus, the capelin, occurred,
and the more southerly types such as mackerel and Sehastes, as before. Outside of
the gulf, cod eggs were scanty, but the whiting (Merluccius), sometimes called hake,
were plentiful. For this scarcity of eggs and young fry the usual explanation (as in
European waters) is that they are swept in vast quantities from the spawning and
hatching grounds, and may be scattered over vast distances outside the gulf of St.
Lawrence. There is no reason to suppose that after the huge schools of parent cod
have cast their eggs into the waters inside the gulf, they perish, although the tempera-
ture may be as low as the freezing point, or lower, 31° to 32°F. ( — 1-a to 0°C.). in
Europe, floating eggs such as those of the cod rarely occur in water under 35° or 36° F.,
but the fishing experiments in the gulf of St. Lawrence showed cod to be abundant
in the vast cold water layers immediately above the bottom, and the eggs are deposited
under these frigid conditions, and undergo their early stages of development there.
It is truly a remarkable result of Dr. Hjort's Canadian researches to find (as he
states), " cod spawning on the floor of the banks in water of absolutely Arctic tempera-
ture," while at the surface, immediately overhead, more southern forms, such as the
mackerel, also spawn.

Dr. Huntsman's interesting quantitative and qualitative plankton research con-
firms the observations, made during the expedition, that the minute floating life in
the Canadian Atlantic waters is more abundant in colder water and where the water
is deep, while on the whole, these myriads of small living organisms are at a deeper
level during the day than during the night.

Professor Willey and Dr. Huntsman made a study of special plankton groups,
the former reporting on the Copepods, the latter on the Chaetognatlis, and their reports
demonstrate a remarkable agreement between distribution and the various water layers
so exhaustively treated by Mr. Sandstrom in his elaborate report on the hydrodynamics
of the waters investigated, and by Mr. Paul Bjerkan in his very thorough hydro-
graphic investigations, including the distribution of temperature and salinity. The
former reports on the phyics of the sea — too technical and detailed to summarize,
but the presence of a great cold intermediate layer is a striking feature, and due, as
pointed out in the report, to ice melting in the gulf or even in the more northerly
Arctic areas, probably as distant as Greenland. The earth's rotation causes it to tend
to the east, or right, and forces it out via cape North into the open ocean.

The salinity features of the gulf and coastal waters, as determined by ^Ir.
Bjerkan, are of peculiar interest. The outflow of relatively fresh water from the
superficial layers in the gulf is more marked in summer than in spring, and one of
its effects is to force seawards, the superficial bank water of higher salinity, 33 to 33,
this influence being noted to a depth of 25 m., but the Salter water, deeper down.

viii PREFACE

forces the banlv water back, especially in the Labrador channel (at depths of 75 to
100 in.), where also the Atlantic water of high salinity, 35°, penetrates farther in
towards the channel in the spring at a depth of 100 to 200 m. As to temperature, the
turface of the gulf is warmer in summer than in spring, owing to the (fresher)
coastal water and the Gulf Stream. In the straits of Northumberland it is as high as
18-5° C. (about 65° F.), while the lowest record is 11-65° C. close up to the north
"shore. In the inner parts of the gulf at 10 m. depth the temperature ranges about
10° C, but in the outer parts at 20 m. an extremely low temperature prevails at 50
to 80 m., especially in the northern parts. There must be a constant inflow of frigid
Arctic water through the deeper parts of Belle Isle straits, as the cold water layers
are more extended in summer than in spring, though this cold influence appears, off
the Newfoundland banks, to decrease in summer. The influence of the Labrador
current and the Gulf Stream introduces many complications, as Mr. Bjerkan shows,
an(| the water-masses of continental origin, of low salinity, add to the complexity,
both superficial and at greater depths. The effects potently influence the breeding,
hatching, and larval development of important food-fishes, and throw light on the
migrations and the distribution of the schools of adult-fish on which our great Atlantic
fishing industries depend.

CONTENTS.

Page

Johan Hjort : Introduction to the Canadian Fisheries Expedition, 1914-1."). . i-xv.

Alf Dannevig: Canadian Fish-Eggs and Larva; 1

Einar Lea : Report on The Age and Growth of the Herring in Canadian Waters. . 75

A. G. LIuntsman : Growth of the Young Herring (so-called sardines) of the Bay

of Fundy 165

Arthur Willey : lleport on the Copcpoda obtained in the Gulf of St. Lawrence

and adjacent waters, 1915 173

J. "W. Sandstrum: The Hydrodj'uamics of the Canadian Atlantic Waters .. .. '221

Paul Bjerkan : Results of the LTydrographical Observations made by Dr. Johan

Hjort in the Canadian Atlantic Waters during the year 1915 349

A. G. Huntsman : Some Quantitative and Qualitative Plankton Studies of the

Eastern Canadian Plankton 405

1. Litroduetion 405

2. Quantity of Plankton 407

3. A Special Study of the Canadian Chaetognaths, their Distribution, etc.,

in the Waters of the Eastern Coast 421

H. H. Gran: Quantitative Investigations as to Phytoplankton and Pelagic

Protozoa in the Gulf of St. Lawrence and outside the same 4^6

"; >-^ ''± * '^

INTRODUCTION TO THE CANADIAN FISHERIES EXPEDITION,

1914-15.

By Jo MAX Hjort,
Director of Fisheries for Xorway, and Head of the Expedition.

(With Five Figures.)

In the course of my researches in Xorth European waters, it has frequently
occurred to me th^t many problems of long standing in the sphere of fishery and
marine investigation might perhaps best be solved by making a comparison between
the two separate areas of sea which contain the same forms of animal life, viz., the
waters of northern Europe, and the range of sea from the coast of Labrador and
Canada to that of Maine.

In 1910, I was invited by Sir John Murray, himself Canadian-born, to make
a cruise on board the ss. Michael Sars, belonging to the Norwegian Fisheries Depart-
ment, the voyage in question extending over the greater part of the northern Atlantic.
Here, naturally enough, the same idea once more asserted itself, and we both felt that
it would be desirable to undertake, at any rate, some slight preliminary investigations
in the Canadian waters, and there make test of the same methods of research as have
been developed, during the course of the past generation, in the fishery investigations
of northern Europe, and the International Council for the Exploratiion of the Sea.

As mentioned in my account of this voyage^ it was also our desire " to set
our course from the Azores to the Bermudas, and thence on to Boston, finishing with
a series of short zig-zag sections between the land and the edge of the coast-banks,
till we reached Newfoundland. "We should in that case have been able to study the
remarkable transition that occurs on passing from the almost tropical conditions of
the Sargasso sea to those of the icy Labrador stream, which creeps southward along
the Labrador coast from Baffin's bay to Newfoundland, and even farther south. Tlie
short time at our disposal made this impossible, and we were compelled to cross from
the Azores to the nearest coaling station, namely, Newfoundland, and then make for
home."

On the way from the Sargasso sea to Newfoundland, however, we had occasion,
after all, to make certain observations, the results of which still further convinced mo
of the great and peculiar interest attaching to such a comparison as that mentioned.
Indeed, this last cruise in itself sufficed to show in what unique degree the waters off
the coasts of Canada and Newfoundland were suited to the study of those very prob-
lems which have ranked foremost in the Scandinavian marine researches of the past
generation, to wit, the relation between the distribution and life-cycle of the organisms,
on the one hand, and the prevalent physical conditions in the sea on the other.

On this cruise, from the Sargasso sea to the Newfoundland waters, we encountered
the sharpest and most remarkable transitions between warmer and colder water layers,
and in the closest connection therewith, a constantly coinciding occurrence of plant
and animal communities, which were now of tropical, now of distinctly northern
boreal character. It was these observations of ours which furnished me with the lead-
ing principles on which the investigations described in the following pages were subse-
quently based. And as, moreover, these earliest discoveries of ours afford a kind of

1 Sir John Murray and Johan Hjort : The Depths of the Ocean. Macmillan, I-ondon.
1912. Chapter III, pages 99 and following.

xi

xii DEPARTMENT OF TEE NAVAL SERVICE

rough introductory survey of those Canadian waters which I was later able to study
in closer detail, it may perhaps not be out of place to give some of the leading features
here.

Fig. 1 shows a temperature and salinity section from the Sargasso sea to New-
foundland. " At stations 64 and 65^ we see the vast layer, with a salinity of over 35
per thousand and high temperature down to considerable depths, the same as found
bj us over the whole distance from away beyond the Canary islands.

" On our way north from station 64 on 2'8th June we saw patches of Sargasso weed
all the morning, and numbers of flying fish, about 10 centimetres long, started up
in front of our boAvs. This led us to believe that we should capture the same forms
as before, when we lowered our pelagic appliances in the evening at station 66. Great
was our astonishment, therefore, to discover next morning on hauling in our appli-
ances that the catches mainly consisted of true " boreal ". plankton, that is to say,
animal forms which we were accustomed to get in the so-called extension of the

Newfoundland bank

atat7Z 71 70

Cargasso Sea

3-88-34 96

3 7 2-3^ "-i

Fig. 1. Hydrographical Section from the Sargasso Sea to the Newfoundland Bank.
Gulf Stream in the ISTorweg^an sea right up to the very shores of Sitsbergen. There
was the amphipod Euthemisto, the copepod Eucliceta, and " whale's food " (the ptero-
pod Clione limacina) , large quantities of which are met with from time to time in the
waters between Spitsbergen and the north of Norway. This last is not an " arctic "
form, that is, it is not associated with polar water in the Norwegian sea, but on the
contrary is found in Atlantic water to the south of Iceland, according to Danish
observations. It seems, however, to be associated with the northern portion of the
Atlantic and the Atlantic water that enters the Norwegian sea. These animal forms
were entirely absent during the whole of our cruise from the Canary islands to
station 64, so that their occurrence at station 66, where lower temperatures were
recorded at no great depth beneath the surface, is very significant.

1 hoc. cit.

iC'.-1-A.i/'/ 1 \ ri>iii:h'ii:s i:.\I'i:iuti(>\. r.ii',-ir, xiii

'• We fancied now that we had said farewell to the Sargasso sea aiixi its interest-
ing animal life, but at stations 67 and 69, in close accordance with the hydrographical
conditions depicted in fig. 93 (fig. 1), we came once more across more southerly forms.
In the upper layers there were the same young fish, many of them with .stalk-eyes, and
Leptocephali, while flying fish, Sargasso weed, and the familiar Sargas.so animals
were all once more in evidence.

" We found a large cluster of eggs, weighing approximately a kilo., drifting about
at station 69, belonging to the common angler-fish (Lophius piscatorius) , the develop-
ment of which was studied by Alexander Agassiz; we hatched out the eggs and
obtained the stages depicted by him. Angler-fish only inhabit the coast banks, so
that our find of slightly developed eggs, that could not have been drifting many days,
indicated that we were now in the neighbourhood of the American coast bank.

" In deep water we found once more at stations 67 and 69 the deep-sea animals
of the Sargasso sea, that i-S to say, all the black fishes and red crustaceans which we
have so often mentioned already. There were not merely the commonest kinds of
small fish, but also large ones (such as three examples of Gastrostomns), and fishes
which are caught in other oceans (Aremtia.'^. Serri vomer).

60

fLEMliH CAP

.BANK OF ; :
\ST PIERRE :-G.».'h

^

'3iABI.E 1.

B A \ N K

70

Fig. 2. " Michael Sars ' Stations 69 to 8u.

'•' At station 70, on the edge of the coast bank, where the depth was 1,100 metres,
we discovered that we had for the second time left purely oceanic conditions behind,
and once more the true boreal plankton appeared in the surface layers. There was
the little copepod Ualanus finmai'chicus, the commonest crustacean in the Norwegian
sea, and we also now met with Euthemisto, Nyctiphanes, Krohnia liamata, Limacina
helicina^ and Clione limacina^ all species that are regarded as specially characteristic
of the Norwegian sea. Still in the deep water from 350 metres down to 1,100 metres
we continued to get the familiar pelagic deep-sea fish Cyclothone signata and C.

1 Limacina was taken in numbers by Haeckel and Murray off Scourie in Scotland.

xiv DEPARTME'NT OF TEE NATAL SERVICE

microdon, as well as the medusa Atolla and other forms; so that the area of distribu-
tion of these animals extends from Africa to North America, that is to say, in all the
water from one continental slope to the other."

"The coast bank itself (fig. 94 [2]) offered us a totally different field for study,
which no doubt would have proved very interesting, but unfortunately our time was too
short to attempt systematic researches ; we had to steam for our coaling station, con-
tenting ourselves with one or two shallow stations on the way.

" Fig. 95 (3) shows the hydrographieal conditions from our last true oceanic station
(69) to a station (74) just off St. Johns. It is extraordinary what a sudden change
there is from the warm salt oceanic water to the cold coast water. The curves of tem-
perature and salinity between stations 69 and 70 go down straight like a wall — the
well-known " cold wall " of oceanographers. Over the bank there is a surface layer,
about 40 metres in depth, with a temperature of over 6°C., similar to what we get
in the boreal portion of the Norwegian sea along the coast of Norway. Below that,
however, the temperatures are under 2°C., and even as low as - 1-5°C., that is to say.

Fig. 3. Hydrographieal Section across the Great Newfoundland Bank.

the water may be as cold as what Nansen found near the North Pole. Probably at no
other part of the globe are there such peculiar temperature conditions — conditions
comparable with those in the Arctic regions, though the latitude is the same as that
of Paris. It would have been an agreeable task to trace these conditions by follow-
ing up the currents and animal life, both northwards and southwards. Still, even our
random investigations furnished interesting results. Thus we discovered that from
station 70 to St. Johns there was the same northerly plankton already mentioned, and
an examination of the young fish showed that they accorded with what had previously
been found by Norwegian naturalists off the coast of Norway, and by the Danes south
of Iceland.

" On the outer side of the coast bank, at station 71, we met with larvae of red-fish
(Sehastes). At station 72 there were cod-eggs and numbers of little cod-fry, besides
fvdly developed eggs of haddock (Gadus ceglefinus) and haddock larvae, 3-| millimetres
in length and upwards, and also young fish of the boreal long rough dab (Drepanop-
seita). At station 73 we came across eggs of this dab (besides a number of eggs that
we have not yet determined), and the shallow- water form Ammodytes. At station 74
there were neither eggs nor young fish.

" Similar catches are taken off the coasts of Norway and Iceland ; near and just
beyond the continental edge there are larvae of red-fish, and on the bank, in 30 or 40
fathoms of water, there are larvae and eggs of cod and haddock. It was interesting to

CANADIAN FISHERIES EXPEDITION, 191/rlo xv

find the eggs and larvae of these fish at station 72, where the bottom-temperature was
between 2°C. and4-6°C., whereas nearer land, where the bottom-temperature was 0°C,
or even less, they were absent."^

In 1915, I had the honour of being invited by the Biological Board of Canada to
make a stay of some months' duration in that country in order to study the Atlantic
herring fisheries of Canada; an invitation which I was extremely happy to accept. I
could not, of course, hope to accomplish very much in so short a time, especially as I
had no prospect of being able to procure the necessary means for practical research
work at sea. The investigations of recent years, however, with regard to the growth of
various species of fish — and particularly of the herring — had shown that it was pos-
sible, by studying the growth of the fish and age composition of the stock, as expressed
in the annual rings of the scales, to form a remarkably close estimate, not only of the
biology of the separate species, but also of the conditions in the sea wherein they
occurred. It seemed to me, therefore, worth while to see whether such investigations,
albeit here necessarily of an occasional and by no means final character, might not open
up fresh points of view, and lead to further and more detailed study in the same field.

The main objects of such scale investigations should then, it seemed to me, be for-
mulated as follows : —

1. Do the herring that visit the Atlantic coast of Canada all belong to a single
race or type, or is it possible to distinguish several races in these waters?

2. Does the rate of growth vary according to the conditions of the waters along
the coast? Can types of different growth be distinguished and defined?

3. Is the renewal of the stock of herring of a constant character, or are there the
same great fluctuations in the stock, i. e., in the number of individuals in the different
year-classes, as in European waters ?^ '

The first two problems, or groups of problems, are of course identical with the
problems of the distribution and migrations of the herring. If the Atlantic stock of
herring can be shown to belong to several different races, then of course the area of
distribution and migration of each race or type may be defined by a study of samples
of herring taken from different localities along the whole coast.

The third problem is of the greatest importance for any elucidation of the old
riddle — the fluctuations in the yield of the fisheries — this being to a very great extent
dependent upon the fluctuations in the number of herrimgs living in the sea at the
time.

On arriving at Halifax, therefore, in October, 1914, I first of all endeavoured to
organize a collection of material. I had no other means at my disposal than such as
could be contained in the not very extensive luggage of an ordinary traveller, and it
was thus useless to think of anything beyond samples drawn from the catches brought
in by the fishermen' themselves. In other words, my material would have to consist
of salted herrings purchased from various localities. Thanks to the very kind assist-
ance afforded me by the Biological Board, especially by the Dominion Commissioner
of Fisheries, Prof. E. E. Prince, and by Prof. A. B. Macallum, Secretary-Treasurer of
the Biological Board, who endeavoured by every means in their power to facilitate my
researches, I succeeded in obtaining samples from various parts of the gulf of St.
Lawrence, and from Newfoundland. It was necessary, however, to form some idea
as to the representative value of the samples thus obtained, and with this end in view
I made a .iourney along the coast, in the autumn of 1915, and over to Newfound-
land, visiting the fishing stations, and taking every opportunity of ascertaining, by
conversation with the fishermen, what kind of implements were employed for the
capture of herring, and what experience the fishermen themselves had acquired as
to the occurrence of the fish. In some places, I was able myself to study the fishing
in progress, and examine the implements used. The fishermen everywhere, almost

1 Loc. cit. p. 106, and following.

2 See my paper : Fluctuations in the Great Fisheries of Northern Europe. Rapports et
Proces-Veirbaux, Vol. XX, Copenhagen, 1914.

xvi DEPARTMENT OF THE NAVAL SERVICE

without exception, use gill-nets with a certain fixed size of mesh (2| to 2| inches).
The nets are placed along the sea-bottom on the coast or in the bays or inlets along
the shore. At no point is fishing carried on far out from the coast in deep water, or
on the surface (by drift-nets or by purse-seines).

As pointed out in a preliminary report of my journey'^ " this particular method
of fishing " naturally " has great disadvantages for the study of the life-history of
the herring. The big meshes of the fishermen's nets can procure samples of the large
mature herring only, and it is further quite uncertain whether the samples are in any
way representative of even the mature shoals or not. It may be that the fishermen,
through a long experience of fishing in these waters, have been able to adopt a size of
mesh which takes practically all the sizes of mature herring visiting the coast, but
only by means of experiments, carried out with gear taking all the sizes probably
occurring, can this question be satisfactorily answered."

In the course of the winter 1914-15, I had now occasion to study the samples col-
lected, primarily with a view to ascertaining how far it might be possible, with such
material, to arrive at an understanding of, at any rate, some points in the natural
history of the herring. The biological laboratory at the University of Toronto afforded
me excellent facilities for this work, and it was there that I can-ied out the investiga-
tions referred to in my preliminary report above referred to.^

As will be seen from this, the samples collected distinctly showed that there are
on the coasts of Canada types of herring differing widely one from another. The
scales were eminently suited for investigation purposes in the case of all samples
from the northern parts of the waters concerned, as, for instance, those
from Newfoundland and gulf of St. Lawrence (e.g. Magdalen islands), whereas the
samples from the west coast of Nova Scotia were far more difficult to deal with.

It was very interesting, at the outset, to find that samples from so small and
restricted an area as the gulf of St. Lawrence should present such clear and definite
differences in the manner of growth as those here found. The herring from the west
coast of Newfoundland, for instance, were distinguished by a poor growth during the
first years, and a long continued later growth, while those from the waters around
Prince Edward island and the Magdalen islands showed considerable growth for the
first years, followd by a more rapid decline in the annual increment. This difference
Avas, moreover, strongly supported by the results arrived at on studying the age com-
position of the samples. The Newfoundland saniples, both those from the autumn of
1914 and those from the spring of 1915, all showed a distinctly marked abundance of
fish from the year-class 1904, whereas in the samples from the southern parts, a very
different composition was apparent.

Some preliminary investigations as to the " racial " characters of the herring
(number of vertebrae, keel-scales, etc.) revealed a state of things such as, in European
waters, has only been observed in the Baltic and the White seas ; that is, from enclosed
waters with a very low winter temperature and low salinities. These racial investiga-
tions likewise tended to support the view obtained by growth investigations and study
of the age composition, to wit, that real differences were discernible.

I had now succeeded in making clear, even with the primitive methods here
employed, tliat the herring from the coastal waters of Canada differed widely as between
one part and another of the region concerned. This result in itself must be regarded
as of great importance, since it threw light upon the area of distribution (migration)
of the herring, and paved the way for closer investigations in the future.

It seemed to me, therefore, desirable to endeavour to carry out more comprehen-
sive investigations on a larger scale, throughout the whole of the waters in question,

1 Investigations into the Natural History of the Herring in the Atlantic Waters of Canada,
1914. Supplement to the fifth annual Report of the Department of the Naval Service for the
fiscal year ending March 31, 1915, Ottawa, 1915.

2 Loc. cit.

CANADIAN FISHERIHi^i EXl'EDlTKtX, 191.',-15 xvii

and instead of restricting the work to a single species, and a single method of operation,
to employ, as far as possible, most of the methods which have been developed in fisherj-
investigations of recent years.

Tliis proposal was most kindly received, by the Biological Board, in the first
instance, and subsequently also by the Department of Naval Service, in particular by
the Deputy Minister, Mr. G. J. Desbarars, himself keenly interested in scientific
research. I therefore conferred with the Dominion Commissioner of Fisheries, Prof.
E. E. Prince, and drew up, in collaboration with him, a programme of work. The idea
was to collect, by short cruises made with vessels belonging to the Canadian Govern-
ment, a quantity of material such as would serve to elucidate both the conditions
with regard to marine currents, and the character of the fauna in the sea from New-
foundland to Halifax, and in the gulf of St. Lawrence itself.

There being no vessel in Canada specially built and equipped for fishery investiga-
tions, and the general tonnage available being much in demand for other purposes, it
was necessary to confine operations to the carrying out of veiy simple investigations,
comprising short cruises at times previously determined, and along certain definite
routes. It was evident, moreover, that only the simpler forms of implements and
apparatus could be used; for the hydrographical work, for instance, water bottles and
thermometers, and for the fishery work, silk nets for studying the distribution of fish
eggs and plankton. I considered it highly desirable to cover the same routes at least
twice; once in the spring, at the time when the most important species of fish would
presumably be spawning, and once later on in the summer, when we might hope to pro-
cure fish lavvce in the more easily recognizable stages.

Apart from the work on these routes, it seemed to me that we should also endeavour
to carry out fishing experiments with a small steam drifter, the No. 33, belonging to
the Government, and which had previously beeu employed for practical experiments.
I hoped thus to obtain samples of another and more valuable sort than those taken
from the fishermen's hauls, and also to ascertain whether herring could be taken with
drift nets of different sizes, especially in the gulf of St. Lawrence.

The plan thus formed was most cordially and liberally adopted by the authorities
concerned, and in the spring of 1915 we set to work getting together the requisite
implements and apparatus. I was here fortunate in being able to procure the assist-
ance of two of my former colleagues, Capt. Thor Iversen and Mr. Paul Bjerkan, with
whom I had worked together for years past, and who now found time to come over for
some months in 1915 and help in the work. With their aid, the following instruments
and apparatus were collected.

(a) For the hydrographical work:

Six Nansen water bottles, made in Norway.

Ten Richter reversing thermometers from Schmidt and Vossbcrg, calibrated to
0-1° Centigrade, delivered by the International Hydrographical Laboratory at Copen-
hagen, which also provided us with two liand-winchos, with wire and reels taking about
500 metres of wire of about 4 millimetres diameter. A meter wheel of the usual pat-
tern for oceanographical research was used for determining the depths. Several water
bottles could be used at the same time.

(6) For the hiological ivorh:

A large number of Michael Sars plankton nets of 1-meter diameter, and oi the
type found most suitable by the Norwegian Fishery Investigations. A description of
this form of net will be found on p. 46 of my account of the cruise of the Michael Sars
in the Atlantic in 1910 ^. Several of the nets were also furnished with closing
mechanism, according to the model described by Nansen.

1 " Depths of the Ocean."
G551— B

xviii DEPARTMENT OF THE NATAL SERVICE

(c) For use on hoard the fishing steamer No. 33:

A number of drift nets with different widths of mesh, with cable and buoys. A
number of cod lines and other implements for capture of cod and other fish, as aiso a
small shore seine.

At the commencement of May, 1915, I made a reconnoitering tour to Prince
Edward island, together with my friend. Prof. Arthur Willey, of McGill Univer-
sity, Montreal, who, to my great satisfaction, had agreed to take part in the expedition.
On our arrival there, on the first of May, the sea all around the island was still full of
ice as far as one could see, and it was stated that the pack ice lay north of the island
and round the Magdalen islands. This state of things lasted all through the week,
until the 8th of May. We learned that the ice had set southward over toward Prince
Edward island from the northern parts of the gulf of St. Lawrence. Northumberland
Ftrait and the Pictou coast were also blocked by ice, even the steamer connection hav-
ing been stopped. The C.G.S. Princess twice attempted to force a passage through the
ice in order to take Professor Willey and myself out on a preliminary survey cruise.
-At last she reached Charlotteto^vn, and we started on the 10th of May for the Magdalen
islands. We succeeded in taking some few stations, which gave some interesting
material for the study of temperature conditions and the incipient development of the
plankton, but the cruise was unfortunately interrupted, as the commander of the
vessel, Mr. Wakeham, was taken very seriously ill, and had to be brought home.

By the middle of May a sudden change took place in the state of the ice. About
the 20th of that month, the Halifax newspapers stated that the ice had been driven by
northwesterly winds towards the Gut of Canso, and about the 25th, the remainder had
either melted, or been carried out of the gvilf. This state of things was generally
regarded as unusual. Both on land and at sea the general opinion was that the ice
should have heen gone six weeks before. As it was, the delay produced its effect upon
the fishing industry ; the herring fishery round the Magdalen island was a failure, and
the herrings taken came unusually late.

After this preliminary survey of the ground, a definite plan was drawn up for the
work, the Canadian Government placing at our disposal the two cruisers Princess and
Acadia, and the fishing steamer No. 33. The Princess, now under the command of
Capt. J. Chalifour, vice Cormnander Wakeham deceased, was to make two cruises in
the gulf of St. Lawrence : the first in June and the second in August.

The Acadia, under Commander F. Andersen, was to make two cruises, between
the south coast of Newfoundland and Halifax, as nearly as possible coincident with
the cruises of the Princess.

The No. 33, under Capt. Thor Iversen, was to carry out fishing experiments in
the gulf of St. Lawrence, and, in addition, to make occasional hydrographical observa-
tions and collections of plankton. At Souris, P.E.I., a temporary laboratory was estab-
lished, where the material from the cruises could be collected and subjected to a
preliminary examination.

The scientific work on board the two cruisers was carried out by myself, with
the assistance of Prof. Ai-thur Willey, Dr. A. G.. Huntsman (University of Toronto),
Curator of the Atlantic Biological Station of Canada, and, for a shorter period, of
Mr. Nightingale of the United States Bureau of Fisheries.

All members of the expedition worked at the laboratory at Souris between cruises,
and Mr. Paul Bjerkan, with Prof. James W. Mavor, now of Union College, Schenectady,
U.S.A., were occupied there throughout.

The first voyage was made by the C.G.S. Acadia, which cruised from the
29th of May to the 4th of Oune from Halifax over the continental edge towards New-
foundland and the entrance to the gulf of St. Lawrence. In the course of this cruise,
tlnrty-six stations were taken {Acadia stations 1-36).

From the 9th to the 15th of June, the Princess made her first cruise in the gulf,
in the course of which twenty-three stations were taken (Princess stations 3-26).

C'-LV.l/J/.l \ rislli:h'/KS EXl'EDITiOX, I'Jl'i-ir, xix

These tun cruises are charted in fig. 4, wliieh tlius represents the first investiga-
tions made in spring or early sunnner.

From the 21st to the 29th of July, the C.G.S. Acadm made her second cruise in
the waters off the coasts of Nova Scotia and Newfoundland. This gave the Acadia
stations 37-91

Immediately after this, the ('.(i.S. Princess made her second cruise, from the
yrd to the 12tli of August, in the gulf of St. Lawrence, with stations 27-50.

Fig. 4.

These two cruises are charted on tig. 5, which thus shows the investigations
of the late surnraer period.

Throughout the whole of this time, the No. 33 was working in the gulf of St. Law-
rence, and collected there a considerable quantity of material.

Subsequently^ also, it was found highly desirable to procure hydrographical
observations from a later season of the year, and it was therefore a source of great
satisfaction to me when Commander F. Andersen, who had taken the keenest interest
in the investigations carried out on board, undertook to make a cruise off the coast

XX DEPARTMENT OF THE NAVAL 8ERYICE

of Nova Scotia later in the year. This was effected in Novemher, the voyage occupy-
inig the time from the 14th to the 22nd of that month. The route followed will be
found charted on fig. 8, p. 374.

These cruises yielded altogether a very lai-ge amount of material, the treatment
of which naturally called for the services of several experts. Needless to say, I had
looked forward to taking part in this work myself, but as it turned out I was pre-

Fiff. 5.

vented from so doing, as on my return to Norway in September, lOl.'J, 1 found myself
compelled to devote my whole time and energy thenceforward to the handling of
important questions in connection with the Norwegian fishing industry, which in the
autumn of that year was in a critical state. Under these circumstances, it was a
great satisfaction to me to know that the material was to be dealt with by pre-emin-
ently competent hands. A complete and exhaustive treatment of the whole of the

CANAiuw Fisiii:nfi:s i:\i'i:nn loy, iui',-i.j xxi

material collected would, of course, be out of the question here, but the papers
included in the present volume will yet suffice to give a survey of the most important
results attained. The reader will here find: —

The hydrographiical material dealt with in two separate papers. Mr. Paul Bjerkan
gives (pp. 349-403) a survey of the distribution of salinity, temperature, and density
in the waters covered by all cruises.

Then, on the basis of the data furnished by ^fr. Bjerkan, ]\rr. J. W. Sandstrom has
(pp. 221-341) subjected the entire question of dynanrc (onditions in itip Canadian
waters to a thorough and most valuable investigation.

The great mass of the plankton material could not, of course, be dealt with exhaus-
tively here; to do so would, at any rate, have required a far longer time than that which
has actually elapsed since its collection. It is the more fortunate, then, that Dr. A. G.
Huntsman, in addition to his record of the hauls made (pp. 405-420) has found time
and occasion to give an interesting example showing the occurrence of a single animal
group in the material (Chsstognaths : pp. 421-485). We have, furthermore, an extremely
valuable contribution by Professor Willey, on the important group of the copepods, the
distribution of which is here dealt with by a method now applied for the first time
(pp. 173-220). On most of the cruises, in addition to the net hauls, water samples
were preserved for subsequent study of the pelagic plants, which are dealt with by H.
II. Gran, according to methods developed by himself. Professor Gran's paper will be
found on pp. 489-495.

Under the heading of plankton, also, we must of course reckon the pelagic fish
eggs, which form the most important grouji of all from a fishery x)oint of view. These
are dealt with by Mr. Alf. Dannevig, and the distribution of these forms in the Cana-
dian waters is here described for the first time.

Of the considerable material dealing with the biology of the fishes concerned, we
have up to the present only been able to complete the report concerning the growth and
age of the herring, composition of the stocks, migrations, etc. Mr. Einar Lea has in
his paper (pp. 75-164) not only treated the whole of the available material — and tliis
far more exhaustively than could be done in my preliminary report above mentioned —
but has also furnished a general introduction to the methodical aspects of heiTing
investigations on the whole, and to the study of the problems which can now be dealt
with thereby. Mr. Lea's paper, like that of Mr. Sandstrom, will be found to afford a
guide to thestudy of these questions applicable in itself to far more than the restricted
and particular sphere embraced by the actual investigations concerned in each case.

A contribution to the study of the younger year-classes of herring from the
southern part of the Canadian waters, the Pay of Fundy. is given by Dr. A. G.
Ilnntsman (pp. 165-171).

I venture to hope that the work thus produced may, albeit by no means exhaustive
or altogether comprehensive in itself, yet serve in principle and by example to pave
the way for further research, and awaken new interest in the study of these Canadian
waters, which offer such remarkable and valuable features for investigation. I trust.
also, that the scheme of work laid down, and the nature of the material thereby pro-
cured, for which I am of course responsible, may prove to be justified by the results
attained. It might seem tempting in various ways to endeavour to collect the various
separate investigations here given into a single whole. I have refrained, however, from
any attempt at so doing, partly because it is perhaps too early as yet to think of this,
and partly also because I myself would infinitely rather that the reader should have the
advantage of consulting the excellent reports themselves, not a mere extract of the same.

On the other hand, it will doubtless be advisable to give here, in the form of intro-
ductory remarks, some general idea of the principles followed thi'oughout the cruise,
with some reference, also, to the experience gained in the course of the actual work on
board, which will best explaim the particular manner in which the researches were
carried out.

DEPAKl'MENT OF THE NAVAL SERVICE

THE HYDROGRAPHICAL INVESTIGATIONS.

A description of the submarine physiography of the Canadian waters lias been
given by J. W. Spencer (seo chapter IX of Sub-oceanic Physiography of the North
Atlantic Ocean, by E. Hull, London, 1912, and Bull Geol. See. Amer. vol. XIV, 1903,
1>. 207), of vphich a brief summary is given by Dr. Huntsman (p. 479 and following
pages) which latter I will draw upon here, as it affords an excellent introductory view
of the waters investigated.

As will be seen from Mr. Sandstrom's chart (pi. 1), the continuation of the St.
Lawrence river forms " the submerged Laurentian valley cutting across the middle of
the St. Lawrence gulf, and passing through Cabot strait and between St. Pierre bank
and Banquereau. We have referred to this as the Laurentian channel. Another
channel, the Cansan, cuts through between Sable Island bank and Banquereau. Far-
ther to the south is the Fundian channel, i)assing out from the Bay of Fundy and
through the gulf of Maine. These three channels delimit two portions of the continen-
tal shelf off Nova Scotia. That to the north, between the Laurentian and Cansan
channels, includes the Banquereau, Misaine, and Cansan banks, and may be called the
Breton portion of the shelf, or the Breton bank, since it lies off Cape Breton island.
The southern part lies between the Cansan and Fundian channels, and includes La
Have and Sable Island banks. It may be called the Scotian bank, since it lies against
the main portion of the province of Nova Scotia.

" In the St. Lawrence gulf we have, to the north of Auticosti island, the Anti-
costian channel, and running north towards the straits of Belle Isle, the Esquimau
channel. To the south of the Laurentian channel, in the gulf, is an extensive sub-
marine plateau, with, for the most part, less than 30 fathoms of water covering it.
Cropping up from it are the Magdalen islands and Prince Edward island ....
We have referred to it as the Lower Gulf region. It might be called the Magdalen
bay."

Prior to the cruises described in this volume there existed a series of excellent
hydrographical investigations carried out by Dr. W. Bell Dawson, p^^blished in the
reports of the Tidal and Current Survey of Canada for the years 1894 to 1913. Dr.
Dawson made determinations of specific gravity (density), and also some temperature
measurements. He has described the current of fresher (lighter) water layers Avhich
spreads from the St. Lawrence river along the Gaspe coast and out over the Magdalen
bay, as above defined. This current, called the Gaspe current, runs farther out along
the south side of Cabot strait as a Cape Breton current. ^

From the sea outside another current makes its way into tlie gulf along the north
side of Cabot strait off cape Ray, spreading out along the north side of the gulf. Out-
side the gulf, the water was far less known. As pointed out by Dr. Huntsman, there
was known to exist " a slight westward tendency on the southern coast of Newfound-
land, and a southwestward drift along the outer coast of Nova Scotia."

In the gulf of Maine, on the other hand, the currents have been more thoroughly
investigated; there are, as we know, the excellent investigations of many years carried
out by Dr. H. B. Bigelow in these waters. Before commencing the present researches,
as also during the progress of the same, and afterwards, I had frequent opportunities
of diiscussing with Dr. Bigelow himself, the questions involved, and I may say that the
present work has greatly profited thereby.

The fir.st cruise made in connection with the present investigations was, as men-
tioned above, that of the C.G.S. Acadia, from the 29th of May to the 4th of June,
1915. The vessel started from Halifax, the primary object being to take a section of
the westerly drift off the east coast of Nova Scotia, and determine the volume of the
mixed layers between the coast and the warmer water of the open ocean. The reader
will best be able to follow the course of this cruise by referring to Sandstroms figs, on

^ For a closer study of the hydrographical features in detail, it will be better to consult Mr.
Bjerkan's sections and tables (pp. 379-403).

CANADIAN FISHERIES EXPEDITION, /9/.}-/.J xxiii

pis. 2, 4, and 6, where the sections of the spring hydrographical cruises are drawn in
situ. On examination of these, it will be seen that the first observations immediately
revealed the existence of a distinctly marked light coastal layer with low tempera-
ture. At the outermost station (section V, 10) the warm and salt ocean water was
encountered. In the course of the cruise two pronounced temperature minima (below
0°C) were met with, one off Halifax and one off the Continental Shelf. In the latter
case, the temperature at 75 m. depth reached the extremely low figiire of -1-7° C.
(Acadia station 12).

It was obvious, of course, that the former of these two minima must be due to a
cold (and fresher) current from the gulf of St. Lawrence, while the other would pre-
sumably be the last outpost of the cold Labrador current, already encountered by the
Michael ^Sars in 1910, and here shown in the section, fig. 1, as mentioned in the fore-
going.

It therefore seemed to me imperative to shape a course up towards the banks south
of Newfoundland, in order to rediscover this water layer, if possible. This we suc-
ceeded in doing (see Sandstrom's pi. 4, sections VI and VII, stations 21-25), find-
ing the sea floor on the banks covered with a cold layer, th6 temperatures going right
down to -1-4° C (station 24), or about the same figure as found ])y the Michael Sar.s
in July. 1910, off St. John's Newfoundland.

This point heing thus disposed of, the sections VIII and IX were then taken, with
a view to obtaining good sections both of the water pouring into and out of Cabot
strait, and of the connection between the outward current from the gulf of St. Law-
rence and the westerly drift off Halifax. Sandstrom's pi. 4 shows at a glance how the
temperatures alone suffice to reveal the connection between the cold water layers from
the gulf round cape Breton and along the coast of Nova Scotia. Furthermore, we
notice the inflow from the Newfoundland area into the gulf, along the north side of
(Jabot strait; and finally, the sections also indicate the connection between the cold
Labrador water and the temi^erature minimum off the Continental Shelf on the outer
side of the Sable Island bank.

From the 9th to the 15th June, or only five days after the conclusion of the
Acadia's cruise, the C.G.S. Princess set out to continue the investigations in the gulf
of St. Lawrence. Here, two large sections were made across the well-known Gaspe
current, as also one section from the north coast of the gulf to Bay of Islands. PI.
4 shows distinctly the fresher surface layers in Magdalen bay, and along the north
coast, while the eastern part of the gulf has a higher salinity at the surface. It is
interesting to follow the high salinity from the open sea all through the Laurentian
channel in towards the mouth of the St. Lawrence river. The temperatures (Sand-
strom's pi. 6) show that the lower figures, under 0° C represent a great intermediate
layer covering the chief banks in Magdalen bay, off the north coast, and off the wes-
tern shores of Newfoundland. These points are of the highest importance to the study
of all biological questions.

These cruises had thus showed that it was possible to obtain good sections of the
principal currents, and the plan here followed was therefore, in essentials, taken as
a basis for the later summer cruises.

A similar rapid survey of these is best obtained by referring to Sandstrom's pis. 3,
5, and 7, and comparing the same with those for the previous cruises (pis. 2, 4, and 6).

It will soon be apparent that the quantity of fresh water has now considerably
increased, especially on the Gasj^e coast, and in the mixed layers, which are essentially
fresher even far out at sea. A comparison of the two plates 6 and 7 very clearly
■shows the same thing. On the other hand, the saltest water which lies
deeper down seems to have riisen considerably, a feature which calls to mind the funda-
mental investigations of Patterson and Ekman in the Skagerak on the European side,
resembling in many respects these Canadian waters. The figures for temperature
naturally exhibit a marked increase on the surface, and a reduction in the thickness of

xxiv DEPARTMEXT OF THE NATAL 8ERTIGE

the cold intermediate layer. Even in the first half of August, however, considerable
areas on the banks in the gulf of St. Lawrence were found to 'be covered with water
colder than 0° C.

As will be seen from these brief remarks, we had now succeeded in procuring a
material which enabled us to measure the thickness of the various water layers by sec-
tions taken transversely to their direction of movement, and this in the shortest pos-
sible time. We had furthermore been able to repeat such investigations at a later
period. This furnished us with the basis for a theoretical treatment of the material,
and an analysis of the influence exerted by the various factors; the earth's rotation,
melting of the ice, specific gravity, temperature, etc. In Mr. Bjerkan's 'paper, the
reader will find all the precise data concerning the values for salinity, temperature,
and density. And Mr. Sandstrom has endeavoured, on a wide scale, to give a thorough
analysis of the causes conducive to the circulation of the water as a whole, and its
dynamics generally. This is, as iar as my experience goes, the most thorough treat-
ment of these questions which has yet appeared.

We are now brought face to face with a great number of most interesting problems
for future hydrographical investigations.

In the first place, it would be well to ascertain what fluctuations may occur from
the conditions found to prevail in 1915. What variation can take place, for instance,
in the amount of fresh water discharged by the St. Lawrence river, in the Gaspe cur-
rent, in the interchange of water between the gulf of St. Lawrence and the area out-
side, in the great cold intermediate water layer, in the Labrador current, and in the
distance of the warm ocean water from the costal banks? All these questions will
naturally be of the highest importance in th& study of biological problems, chiefly, per-
haps, the varying distribution of the cold water layers. A particularly interesting
feature is the remarkable wedge of the very coldest salt water off the Continental
Shelf (Acadia station 12). Can this current penetrate still further southward in the
spring, and can this be the great cause of the death of multitudes of fish, occasionally
observed in the sea off the east coast of America ? Bearing in mind the state of things
in the North-European waters, as revealed more especially by the Swedish investiga-
tions, there is good reason to believe that the fluctuatiions in the Canadian waters will
likewise prove to be of very considerable extent.

Sandstroom's investigations revealed various possibilities for a further comprehen-
sion of hydrodynamics in the sea. I would here more particularly call attention to his
suggestions as to the study of submarine waves, where fresher layers encounter the
mighty wall of the saltest Atlantic water, or in the intermediate layers in the gulf of
St. Lawrence, or in the current movements of the deeper layers, as, for instance, those
in the Laurentiian channel.

PLANKTON' INVESTIGATIONS.

The scientific, and particularly the quantitative study of plankton in the sea has
long been a subject of discussion giving rise to widely divergent views. Hensen and
his followers have emphatically maintaied that only quantitative investigations could
lead to results of any scientific value, and that the methods developed by Hensen him-
self afforded satisfactory means of ascertaining the quantitative occurrence not only
of separate species, but also of the total plankton in a column of water corresponding
to the range filtered by the Hensen net from bottom to surface. Other investigators,
again, were indisposed to bind themselves to such methods of research, or to accept the
given formula'tion of the problem. It has been pointed out, for instance, that the
method in .question was not altogether satisfactory in itself, as the nets did not by any
means take the entire plankton content— i.e., all the forms represented— in the column
of water through which they were drawn. And it has also been demonstrated beyond
(luestion that many forms passed .through the nets, while the larger ones managed to
avoid them. Moreover, it has been maintained that both the term " plankton," and the

CA\AniA\ risiiiiiniis h\i'i:i)i i lox, i'ji'i-Ij xxv

idea of a vertical haul were calculated to obscure the true nature of the proposition.
The conception of vertical hauls through the whole column of sea water, under one
S(iuare meter of surface, is undoubtedly derived from the simpler process of soil valu-
ation on land, but the knowledge gained as to the circulation of sea water, wirth its
surface, intermediate, and bottom currents, and the highb' fluctuating velocity of the
same, militates ver\- strongly against the acceptance of the vertical haul as a univer-
sal means of estimntimg quantitatively the production of floating organisms in a given
area.

For the present, then, as long as we still lack a clear and indisputal)lc analysis of
the great group of problems actually invoh'ed by the questions raised, and have yet to
find satisfactory methods of reseax'ch for approaching the same, it would surely seem
far better to content ourseh^es with studying the geographical ((jualitative and quan-
titative) occurrence of cer'tain definite forms, applying in eacli particular case the
methods best suited thereto. This view has previously been advanced by the present
writer ^ and by Prof. H. H. Gran. "We pointed out .that a quantitative estimate of the
plankton in a water layer should at any rate be based upon a combination of samples
drawn from horizontal layers which must themselves be ylefined as closely as possible,
and their i^hysical and chemical conditions investigated at the same time.
In the case of the animal forms, several methods have 'been tried in connection with
such horizontal liauls. .From time to time, there have been consti-ucted more or less
adequate plankton nets, which could be opened and closed at certain depths, and indi-
cate what water they had fished, but the methods hitherto employed can hardly be said
to fulfil the claims of absolute accuracy in these respects. My own personal view has
always been, that it is unjustifiable to attempt a task which the methods of work
available do not suffice to accomplish, and that it is therefore better to recognize
the restrictions inaposed by the fact, and aim advisedly at results which shall be
approximately valid for certain selected forms. On the Michael Sars expedition in
1910, 1 found it most practical, and therefore most effective, in the case of the fishes,
to tow nets through the water at different depths, and then endeavour to ascertain the
catch made at a given depth by statistic treatment of the yield. (Vide "Depths of the
Ocean," pp. 615-617.)

Only in the case of the vegetable plankton have we an altogether satisfactory
method of work, viz., that of H. H. Gran. Professor Gr'an was able to show, that by
preserving water samples (with Flemming's liquid) and subsequently centrifuging
them, we can obtain material sufficient for quantitative determination of the entire
vegetable plankton in the sample. Gran has by this means, as we know, succeeded in
obtaining the first real view of the true plant production of the sea,- his experiments
being carried out in European waters (the Skagerak) which in so many respects
resemble the Canadian. At most of our stations, plankton samples were collected
according to Professor Gran's method, and the material is dealt with by Gran in his
paper here given (p. 489.)

, The paper in question throws light upon some extremely important sides of the
natural history of plankton. As will be apparent from the work itself, the Canadian
plankton reveals marked resemblances to that of the European waters. It differs, how-
ever, in the common occurrence of typical arctic forms, corresponding of course, to the
very low temperatures prevailing in the gulf of St. Lawrence during winter in all the
upper water layers, and in summer throughout the great intermediate layers. A point
of great importance for all conditions of growth in the Canadian waters is the fact
demonstrated by Gran, that the development takes place much later in the year there
than in the waters of northern Europe. This naturally agrees with the fact that the
gulf of St. Lawrence was full of ice until nearly the middle of May — and it is interest-
ing to note, in this respect, that while the growth of the herring in the far more north-

1 See, for instance, "Depths of the Ocean," pp. 771-785.

2 H. H. Gran. The Plankton Production of the North European Waters in the spring, 1912.
Bulletin Planktonique pour I'annfee 1912 public par le bureau du Conseil Permanent Inter-
national pour I'exploration de la mer. Copenhague, 1915.

6551 — c

xxvi DEPARTMENT OF TEE NAYAL SERVICE

erly Norwegian waters commences in April, that of the herring in the gulf of St. Law-
rence does not begin until June; in the case of a single sample, indeed, not until July.
In Lea's paper, also, pp. 158-159, it is pointed out that a similar late growth is kno^vn
from the Baltic, near the coast of Finland — a further example of the similarity
between conditions in the gulf of St. Lawrence and those of European bays.

In considering the collection of animal plankton, there are certain points which
should be borne in mind.

For carrying out the cruises above mentioned, I could only reckon on having the
two vessels, PHncess and Acadia at my disposal for about a month, or, to be precise,
for thirty-three days in all. In order to cover, within this short period, a sufficiently
large expanse of water to give a real survey, it was necessary to arrange beforehand
for the quickest possible method of work, making only a short stay, for instance, at
each station. This was the more imperative, since the frequently boisterous or foggy
weather compelled us to allow a margin for delay, though, as it turned out, we met
with no serious difficulties in this respect.

Moreover, the two vessels, not being built specially for the purpose, could naturally
not offer ideal facilities for plankton work. The Michael Sars, as described in the
" Depths of the Ocean," lies low in the water, and can be easily manceuvred against
the wind, so as to keep the line of a net vertical in the water; our vessels here, on the
other hand, with their higher freeboard, could only take their stations by lying trans-
versely to the direction of the wind, which often rendered it difficult to get vertical
hauls.

Owing to these circumstances, the hauls made are by no means all that could be
desired, especially from the point of view of the Hensen school. The critical remarks
proffered by Dr. Huntsman in his notes on the list of hauls in the present volume (pp.
407-4:20) are therefore entirely justified from this point of view, and the quantitative
figures for volume are really only of value to a limited degree — more limited, in the
present case, than such figures otherwise would be in themselves. They are given here,
nevertheless — albeit, as mentioned, with all reserve — because, to those who are them-
selves acquainted with the fluctuating quantity and quality of plankton generally, they
will be of interest as affording some idea of the order of maguitvide in the present
samples. And in connection with subsequent collections, taken for instance at other
seasons and in other years, as also for further treatment of the material, the figures in
question will doubtless be of some importance after all. They also serve to indicate
approximately the extent of the collections from which the different groups of material
treated separately in the special sections were drawn.

In the case of larger, rarer, and more conspicuous forms, such as fish eggs, fish
larvse, Chaetognaths, treated in the present volume, we endeavoured as far as possible to
count, treat, and examine all individuals in the samples. In such treatment it is
always more or less interesting to note the size of the samples, and the depth in which
the numbers of individuals found were obtained. For forms of less frequent occur-
rence, also, the quantitative approximation is perhaps also satisfactory, but gives, of
course no information as to the interesting question of the precise depth at which the
individuals concerned actually were taken.

The study of fish eggs and fish larvae gave rise, during the progress of the cruises
themselves, to a series of most interesting and important questions.

On the first cruise of the Princess in the gulf of St. Lawrence, (May 29 to June 4),
we encountered a characteristic occurrence of eggs of Gadoid species, in particular
of the cod proper, and of the flatfish Drepanopsetta (Hippoglossoides) all over the
banks, i.e., in what we have called Magdalen bay, at Anticosti, along the north shore,
and off the west coast of Newfoundland. Besides these greatly predominating species,
we found on the banks only eggs and a few larvae of arctic species (Anarrhichas lati-
fron.<?, Mallotus villesus, Icelus, and Agonus decagonus. At the southernmost
stations, we found at Cabot strait the first mackerel eggs, and above the deep Lauren-
tian channel — and nowhere else — considerable quantities of Sebastes.

c.4-\.i/^/.i \ ijsnj:h'ii:s i:.\ri:i>ii los, ini'i-io xxvii

These finds led me to expect that we should, on the later summer cruise, encounter
quantities of larvae of the species in question. To my surprise, however, this cruise
likewise yielded hardly anything beyond cod eggs and only a very few larviv indeed.
A characteristic feature, also, was the fact that we found arctic forms (MuUotus) in
the northern part of the gulf; eggs and larvie of southern forms (Ctenolahrus,
mackerel) in the southern part, with Sehastes, as before, sharply limited to the waters
immediately above the Laurentian channel.

Outside the gulf we found, on both cruises of the Acadia, a scanty occurrence of
cod eggs. Beyond this, I will here only mention a considerable occurrence of Mer-
luccius in this water, and Scopelids out on the edge; these last aflFording sufficient tes-
timony that the investigations had covered the whole breadth of the coastal zone.

The most remarkable point in connection with these hauls was the extreme
paucity of the older egg stages, and of all larval forms. It was therefore necessary
first of all to study the ratio between eggs and larvae in our present material, and to
compare the same with what was known from other waters in this respect. Mr.
Dannevig's paper gives a critical treatment of this question, and it will be noted, that,
as he expresses it (p. 44) " the gulf of St. Lawrence i's considerably behind the other
localities with respect to the occurrence of later stages, both in the case of the earlier
investigation and those made subsequently (Princess I, Princess II, and No. 33).
The ova have evidently a far poorer chance of being developed and hatched than in
other places." The few experimental hauls made by the No. S3, and the information
gleaned from fishermen in conversation also confirmed the view that in the gulf of St.
Lawrence, very few young fish of any species are known to occur at all. The question
is, of course, of vital importance for the study of the stock of fish in the water. How,
then, are we to explain the facts as they appear?

The results of the European fishery investigations lead apparently to the conclu-
sion that all boreal forms of food fish are restricted to water with positive temperature,
rarely occurring, indeed, in water under 2° C. In the Arctic ocean, the Greenland
seaj and the deepest part of the Norwegian sea, where the temperature varies from 0°
to - 1-5° C, only arctic forms of fish are found: here, however, in the gulf of St. Law-
rence and on the Newfoundland banks, we encountered masses of cod eggs floating in
and immediately above thick water layers colder than 0°, even below — 1° C. Our
fishing experiments, with hand lines, for instance, had showed beyond any possibility
of doubt that the cod themselves really were to be found in this cold layer, which
immediately covers the sea floor, while this water contained the very youngest stages of
spawned eggs, but hardly any of the older stages at all. Were we then to suppose that
these millions of fish were here spawning under conditions which doomed their milliards
of eggs to destruction? Naturally, the question could not be answered by means of such
investigations as those upon which we were then engaged : to do so would have required
a vessel, say like the Michael Bars, able to devote itself entirely throughout a whole
season to all kinds of work in the water concerned. Hatching and cultivation experi-
meaits would be necessary, as also intensive experimental fishing for young stages, etc.
Failing all this, and wishing to throw some light upon the problem, if possible, I
applied to Prof. August Krogh and Dr. A. C. Johansen, of Copenhagen, with a request
that they would institute experiments in order to ascertain whether cod eggs from
Danish waters could be satisfactorily spawned and hatched out in water of such low tem-
perature. The results of the experiments made by these two gentlemen are quoted in
Mr. Dannevig's paper, and it will be seen that they give no groimds for supposing that
the temperature alone should ofi"er any hindrance to the development of the eggs.

Again, it might be supposed that the cod eggs were carried out from the gulf, en
masse, as is known to be the case in European waters, where they are transported by
the movement of the water to a great distance from the spawning grounds. The hydro-
graphical papers in the present volume, as also Dr. Huntsman's plankton report, con-
tain numerous facts pointing very markedly in this direction. It is impossible, how-

xxviii DEPARTMEyr OF THE J AVAL HEltVICE

ever, from the present investigations, to come to any final decision here, but the work
done has certainly raised questions of the greatest importance for future Canadian
fisherj^ investigations.

These waters are, of course, extremely interesting from the most general biological
jDoint of view. We find here, in one and the same area, and with only a water layer of
a score of fathoms between, cod spawning on the floor of the banks, in water of absolu-
tely arctic temperature, while at the surface, directly above, spawn southern forms such
as the mackerel, wliich have possibly migrated from the water layers just off the Con-
tinental Shelf where the last remains of the Sargasso weed are still to be found. And
a single haul at the surface will be seen to contain pelagic eggs of both these species of
fish.

Of tlie remaining plankton, only two groups have been dealt with up to the present,
viz., the Cha3tognaths, by Dr. A. G. Huntsman, and the Copepods, by Prof. Arthur
Willey. These two studies afi^ord, however, in themselves, excellent examples of what
plankton investigations can yield in the way of results, and of the methods which
must doubtless best be employed until better implements are available for ciuantitative
study. Of the comparatively large and not so very numerous Chsetognaths, Huntsman
has given estimates for the total number of individuals in the samples. In the case of
the small and numerous Copepods, this was impossible, and the method here adopted
v.'as therefore to determine, from a small selected sample, the percentage of com-
position represented by the separate species. In the case of some few more important
forms (especially Calanus finmarchimis) , Willey has given also the percentages of the
various principal stages of development in the sample.

Thus the two papers illustrate the occurrence of various biological types, viz.,
those pertaining to the oceanic water of the Atlantic, those of the colder boreal water
layers, and finally those of the fresher coastal layers And a study of these plankton
reports, compared with those of the hydrographical work, will give an idea'of the
marked agreement between the distribution of the animal forms concerned and that
of the various water layers.

The results of the fishery investigations proper, i.e., investigations as to the actual
life and occurrence of the fish themselves, cannot yet be given in their entirety, as the
treatment of part of the material is not yet concluded. Up to the present, we have
only Mr. Einar Lea's description of all the herring samples; this section is, however,
after all, the most important part of the work from a biological point of view, and the
primary object of the expedition is thereby attained.

Mr. Lea has in his paper given a thorough explanation of the methods employed
in age and growth determinations, based on examination of the scales, and the work
will therefore, it is hoped, prove useful in future Canadian fishery investigations.

For the rest, I would merely point out that Mr. Lea's careful researches have satis-
factorily demonstrated what the results of my preliminary investigations had already
indicated, viz., that there are in the Canadian waters distinct types of herring,
excellently characterized by their maimer of growth and the difference in age com-
position. His thoroug-h treatment of the material likewise shows that the various areas
exhibit the same peculiarity as has been found so markedly apparent in several Euro-
pean (and especially Norwegian) waters, to wit, the pronounced fluctuation in the
increment of young individuals from year to year, whereby the age composition of the
stock reveals an enormous predominance of some few extremely rich year-classes, while
others hardly contribute in any appreciable degTee to the numerical value of the whole.
The conclusions here arrived at, regarded together with the like results which are
becoming, apparently, more and more common in various spheres of biological research,
force us to admit that hitherto prevalent views not only on leading fishery questions,
but also of general biological problems as to the maintenance of species, and all that is
comprised in the old Malthusian ideas, will need to be essentially revised.

CANADIAN FISHERIES' EXPEDITION, 1914-15

BIOLOGY OF ATLANTIC WATERS OF CANADA

CANADIAN FISH-EGGS AND LARV.E

BY

ALF DANNEVIG

Of the Flodevig Sea-Fish Hatchery, Arendal, Norway

6551—1

CANADIAN FISH-EGGS AND LARVJE

I. INTRODUCTION.

When Dr. Hjort invited me to undertake the work of dealing with his valuable
material of fish eggs and young from the Canadian waters. I was fully aware of the
many difficulties which the task would involve. The determination of ova and young^
from a quarter of the globe where many species of fish exist, whose young stages
have not been described, is naturally no easy matter, more especially when only
prieserved material is available, and it will, as a rule, be obvious from the outset
that complete success must be out of the question. The object of the Canadian inves-
tigations was, however, principally to ascertain the biological conditions under which
the most important species of fish lived and multiplied, so that possible errors in the
deterniiiiatiou of some few of the less frecjuently occurring species would be of
minor importance. In view of this fact, and with the promise of every assistance
from Dr. Hjort and Magister Koefoed, I undertook the task, all difficulties not-
withstanding.

As to how far the determination of species has been successful, it is naturally
impossible to say at present; future investigations of the same waters will, in all
essentials, make this clear. I have thought it proper, however, here to make a few
introductory observations as to eertain i)articular difficulties which may be imagined
as having given rise to erroneous determinations.

The transatlantic literature on the subject being somewhat scanty, I have had
recour.ve more especially to descriptions of European species, and it might therefore
seem not unlikely that related western forms could have become confused with or
mistaken for these; but regarding the young of species found on both sides of the
Atlantic, however, and where good descriptions of the .young stages are available, this
source of error does not apply.

A considerable number of forms have been drawn with great accuracy by Mr.
Rasmussen. these including both species previously described and drawn, and also
other lesser-known species. I have not thought it advisable to give any description of
such forms on the basis of the preserved material, more especially since this would
lie outside the scope of the present work.

As regards the determination of the ova, this is naturally more or less uncertain,
since the eggs of many species are indistinguishable one from another until tlie
embryos are well developed. In some few cases, on the other hand, the ova may be
accurately determined from the time of spawning. It will, moreover, be justifiable to
presuppose relation between ova of like appearance in one and the same sample, where
some are newly spawned and others with the embryo sufficiently developed to permit
of certain determination.

The present material of ova and young was collected by means of a silk net (In?.
diameter) and preserved in 4" per cent formol. The duration of the surface haul.>^
varied somewhat, as a rule between ten and fifteen minutes; the depths, as stated for-
tlie vertical hauls, are also in some cases only approximately correct, owing to diffi-
culties in the working of the net.

Similarly, the records as to quantity should not be taken too strictly, these being
for like reasons only approximate figures. The proportional quantitative values, how-
ever, as between eggs at different stages of development, may be taken as fairly
reliable.

Or).'")l— IJ

4 DEPARTMENT OF THE NAVAL SERVICE

The material was collected in the course of five different cruises, of which two
made on board of C.G.S. Acadia covered a zigzag coiirse between the southern point of
Nova Scotia and Newfoundland, the first extending' from May 29 to June 4, the second
from July 21 to July 29.

In the gulf of St. Lawrence, two cruises were made with the C.G.S. Princess from
June 9 to June 15 and August 3 to August 12; here also, the SS. N° 33, in addition
to its ordinary fishery operations, collected a number of samples during the period from
June 1 to August 18.

-/fcwcZ/a //rs^ cruise ^H-i>6 ^/<-36
second ■■ ^/7-2r7 St 3^-9/

Prjncess f/rst cru/se%-'^/6 5t3-26

second ■■ i/s-^^/s 5 1 27- so

Fig. 1.

Before proceding to the treatment of the material, I should mention that a
quantity of ova and young had already been determined by Dr. Hjort in Canada,
■while Mr. Koefoed also has kindly determined a number of Atlantic fish, and has
further assisted me in doubtful cases with other forms.

CAAADJAN FJStn FRIES EXPEDITION, WVrl5

II. THE MATERIAL COLLECTED.

In the plankton samples, ova and young of thirty-six species of fish have been
determined, representing twentj' families in all.

The si)ecies will be dealt with in the following pages in systematic order, having
regard to their occurrence within the area investigated, their geographical distribution
generally, and certain features in their biology and reproduction.

1. FAM. LABRID^.

Ctenoldbrus adspersus (Walbaum).

(Plate II, Figs. 1 and 2; Table lla.)

„ , ,., r- /• I -100 pr Station all hauls
Pnncess 1 bt J-26 ^99^ i^rr^ore than ,oo

Acadia 1 St 2-36

Lan^ael

C/e/70/adrus

30 pr Station
? than 100 ■
- 10 pr StaTion

)more than lo

Fig 2

■*■ Acadia n St 37-91

Ctenolabrus

^^ ( # I - 100 pr station all hauls

+ Princess n St 27-50 '^J'^^ j Ai^gre t han 100 '

I 0'

- 10 pr station

O^

Fig. 3.

CA\An[A\ FISiHERIK^ EXPEDITIOX , 101 ',-15

'55

Eh^t

Ctenolabrus

I # 1 - loo pr Station all hauls
l^fcmore than loo

Fig. 4.

The young stages of this s])ecies have been shown by Agassiz (On the Young
Stages of some Osseous Fishes, Part III, Ctenolahrus coeruleus DeKay. pi. XIII, and
XIV). I have not, however, been able to identify the species with certainty from these
drawings, buti as the larvae agree very well with the young stages of the related
European form Lahrus rupestris, I have had no hesitation in ascribing the Canadian
material to Ctenolahrus adspersus* According to Professor Ehrenbaum's '' Nordisches
Plankton," the larvae of Tautofja onitis are very similar to those of this species, but
as Tautoga is a southern form, there can hardly be any question of confusion with the
present species.

As will be seen from the illustrations, the Canadian form differs from the European
in having a very distinct massing of pigment at the posterior basis of the dorsal fin.

The diameter of the ova is the same in both species, viz., 0-8 — 0-9 mm.

The distribution of Ctenolahrus adspersus ranges from Labrador to Sandy Hook
(Jordan and Evermann) ; it is a distinctly coastal form, especially affecting rocky
bottom. Ctenolahrus adspersus is summer-spawning; on the first cruise of the Princess
(June I) to June 1.5) but not more than twenty-one eggs of this species were taken.
On the second cruise (August 3 to August 12), on the other hand, numerous larvae
were found, and only very few eggs, most of those found being in a very advanced
stage of development.

♦ Tmitogolabni.y ndsperus Walbaum.

8 DEPARTMEl\'r OF THE NAVAL SERVICE

As will be seen from the chart, ova and young were only found at the stations
nearest the coast, especially in the gulf of St. Lawrence along Prince Edward Island
and Cape Breton.

The material of this species from the Acadia amounts to some few eggs and young
taken at Sable island and farther in near the Gut of Canso.

The size of the young varied between 3 and 9 mm.; (see also tables),

2. FAN. CARANGIDJE.

Capros aper (Lacepede).

,0f this species, only one specimen (total length 6 mm.) was taken, this being
from the Acadia, Station 44, where it was brought up in a vertical haul from 150-0
m. ' Although Jordan and Evermann do not mention this species as occurring in
American waters, I have been obliged to ascribe this specimen to the si)ecies in
question. C. aper is also found, by the way, in the eastern Atlantic right up to the
coasts of England, and it also penetrates into the Mediterranean.

3. FAM. SC0MBRID2E.

Scomber scornbrus (Linnaeus).

(Plate I, Fig. 3: Table lib.)

Of this species, quite a considerable quantity both of ova and young were
collected, especially by No. S3, and on the second cruise of the Princess.

Jordan and Evermann give the distribution of the mackerel along the American
coast as from Labrador to cape Hatteras, and it is therefore remarkable that its ova
and young should here have been found almost exclusively in the southern portion of
the gulf of St. Lawrence. The cruises of the Acadia furnished but three eggs from
stations outside Nova Scotia, and neither the Princess nor No. 33 found ova or young
of mackerel in the northern part of the gulf.

Princess I St 3-26
Acadia I St 2-36

^.^'\^

Scomber scombrus

# 1 -100 pr. Station all hauls
more than loo

Fig. 5.

Fig. 6.

C.4,V.4r>//l.V FISHERIES EX fEfHTIOS , 1011,-1'')

11

Fig. 7.

It would seem that the mackerel here when spawning keep to the shallower waters
in towards Prince Edward Island. It is also interesting to note that while the first
stations on the first cruise of the Princess inside and west of Prince Edward Island
furnished purely arctic species, the hauls made a week laten. on the eastern side of the
island, brought up the first mackerel eggs.

The mackerel's spawning season appears to extend over a considerable period,
from middle of June (first cruise of the Pnn-cess) to some way on in August.

The size of the mackerel ova will be seen from the table; it will be noted that the
diameter varies greatly, a phenomenon which is also well-known in European waters.

Princess. Princess. Priticess. " 33."

MM. Station 26. Station 30. Station 31. Station 29.

1-00 • 23

1-05 9 47

1-10 Ifi 34 - 1

1-1.5 1 1 1 4

1-20 8 12

1-25 11 8

1-30 5 ....

The diameter of the oil globules was about 0-03 mm.

12

BEPARTMEJ^T OF THE NAVAL SERYICE

Mackerel larvae were taken only during the second cruise of the Princess, for the
most part from Prince Edward Island, and out towards the edge, where stations 28
to 34 gave 40 larvae between 3 and 8 mm.

In addition, a single larva of 9 mm. was taken at station 45, this being the only
mackerel larva found on the north side of Cabot strait. At Stations 49 and 50 —
between Prince Edward Island and Cai)e Breton — six larvae ranging from 4 to 6 mm.
were found.

4. FAM. PEDICVLATI.

Lophins piscatorius (Linnaeus).

Of this species , only a single specimen, of 11 mm., was found (Acadia, station 47).
L. piscatorius has a very wide distribution on both sides of the Atlantic; according
to Jordan and Evermanm, it ranges from Nova Scotia as far as the Barbadoes; only
^n deep water, however, is it found so far south.

5. FAM. SCOEPAENID^.

Sehastes marinus (Linnaeus).

(Plate I, Figs. 4,5,6,7; Table lie.)

Young of Sehastes were found in all the deeper parts of the areas investigated,
pave at the outermost stations of the Acadia.

Sebastes

O'-io pi" Station all hauls
Prmcess I St 3-26 ^'^^ O'^^'^ *^^«" "^
Acadia I St 2-36

Fig.

Fig. 9.

14

DEPARTMENT OF THE NAVAL SERVICE

j O I -10 pr Station all hauls
Qmore than lo -/ - v

Fig. 10.

It wovild appear to be most numerous above the deep channel south of Anticostl ;
the -A^o. 3S took here 325 young in a single haul. On the slope towards Newfoundland
also, it is numerous. (Princess station 45.)

On the second cruise of the Acadia, also, by the way. it was found in remarkable
quantities on the banks off Nova Scotia ; this fact may be ascribed to the existence
of large depressions in the banl^s, or possibly to the nature of the currents.

SehaMes marinus is found throughout the northern seas between America and
Eurox>e, both on the slopes of the banks and pelagically above the greater ocean depths.
Jordan and Evermann note it as occurring on the American side from Greealand
lalong the coast as far as midway off New Jersey; from Maine and farther south,
however, in deep water only.

These writers affirm that Goode and Bean found spawning Sehastes late in the
summer off the coasts of New England, at a depth of 100 to 180 fathoms and state
that there is no " reason to believe that the young rise to the surface."

According to Dr. Bigelow, adiilt Sehastes are also found in quite shallow water
(about 10 fathoms) in the gulf of Maine — a very remarkable phenomenon, since
Sehasfes is otherwise both south of this (Jordan and Evermann) and farther north,
chiefly encountered at medium depths.

CA^ADIA^' FISHERIES EXPEDITIOy, 1914-15 15

6. FAM. COTTID^.

Cottus scorpius (Linnaeus).
Cottus huhalis (Euphrasen).
Icelus hicornis (Keinhardt).

Three species belonging to this family are represented in the material, numbering
six specimens in all, these being taken, without exception, from the waters near Prince
Edward island and Magdalen island.

C. scorpius^ JS'o. S3, station 1-4, one specimen of 10 mm.; station 17, one of 11 mm.
This species is found on both sides of the Atlantic, and extends some considerable
distance to the northwaid, as far as Spitzlierjien.

According to Jordan and Evermann, it occurs to the southward along the coast as
far as Eastport, Maine. In the European waters, C scorpius deposits its egg capsules
in midwinter, and the young are subsequently encountered as plankton in the spring.
It is noted, however, that in this species, internal fertilization may take place, and
tbat the ova may therefore be in a far advanced stage of development before being
spawned; this occurs especially in the northerly waters.

C. huhalis (Euph.) Two specimens from No. 3S, station 17 — both of 6 mm. —
agree very well with the larvae of C. huhalis, and have been ascribed to this species,
although Jordan and Evermann regard it as doubtful whether C. huhalis occurs on the
western side of the Atlantic.

Icelus hicornis (Reinhardt) was taken at Princess station 7 (14 mm.) and another
of 10 mm. at No. 38 station 15.

This species is an arctic circumpolar form, penetrating, however, southward along
the east coast of America as far as cai)e Cod. Eoth the specimens here taken were
found in comparatively sliallow water.

7. FAM. AGONID^.

Agonus decagonus (Scluieider).

One specimen of 2^ mm. was taken by the Princess at station 7, and strangely
enough, at the surface. A. decagonus is otherwise found for the most part at some con-
siderable depth, down to a couple of hundred fathoms, and in very cold water about
0° C. As to its propagation, little is known.

Aspidophoroides monopterygius (Bloch).

One specimen of 15 mm. taken by the No. 33 at station 21 (C. Gaspe) should
probably be referred to this species. In point of habitus, it is very like Agonus deca-
gonus, but differs from this in having but one dorsal fin. On the other hand, it has
very spinous scales, and differs in this from A. monopterygius; possibly, however, this
may be a larval character.

8 FAM. BLENNIID^.

Chirolophis sp.

(Plate II. Fig. 8; Table lid.)

Two species belonging to the family Blenniidse were foinid, of which the one could
not be determined with certainty.

This was found (no less than sixty-three specimens) throughout the whole of the
gulf St. Lawrence, and out towards the Newfoundland banks. The number of vertebrae,
about 13-1- 42 or a total of about 55, agrees very well with that of Chirolophis galerifa
(L.) Walb. It differs slightly, however, from this in the shape of the head and
intestines, while the pigmentation appears to be of more or less the same character.

16 DEPARTMENT OF THE NAVAL SPRYWE

It was taken in sizes ranging from 8 to 13 mm. and was most numerous during the
time extending to July 15.

Sticliaeus punctatus (Fabricius).

(Plate II, Fig. 9.)

Of this species, two specimens measuring 30 and 40 mm., respectively, were taken.
Stichoeus punctatus is an arctic lish; it is recorded as penetrating as far southward as
Newfoundland. The specimens in question were taken at the surface, station 89
^Acadia) i.e., down towards Nova Scotia.

9. FAM. CRYPTACANTHODIDJE.

Cryptacanthodes maculatus (Storer),

(Plate II, Fig. 10.)

This species was taken in a vertical haul (80 to 0 ni.) at the Princess station 8.
Only one specimen, of 38 mm. Found from Labrador to Long Island sound — but not
common. (Jordan and Evermann.)

10. FAM. ANAREHICHADID^.

Anarrhichds latifrons (Steenstrup).

Two specimens of A. latifrons were taken, one of 21 mm. in a surface haul
(Princess station 3) and one of 25 mm. in a vertical haul 125 to 25 m. (Acadia station
35). These were so far developed as to be distinguishable by the position of the
vomerine teeth. An arctic fish, extending southward along the east coast of America
to Banquereau.

11. FAM. GALLIONYMIDJ^.

Callionj/mus sp.

A fish larva of 6 mm. taken in a vertical haul 150 to 0 m. Acadia station 44,
strongly resembles the European Callionymus species, but lacks the notochord other-
wise so prominent in these species. The formation of the fin rays, however, was so far
advanced that possibly the notochord may have been reduced.

12. FAM. CYCLOPTERID^.

Liparis sp.

Liparis major (Gill).

(Table He.)

Of the Liparidse taken, three specimens from No. 33 station 57 were ascribed
to Liparis major (vide Jordan and Evermann). They had a total length of 25 to 30
mm., but were not in good preservation, and the determination is therefore somewhat
uncertain. L. major is an arctic fish, extending from the White sea to Greenland,
but, has, according to Jordan and Evermann, not been encountered on the coast of
America.

The remaining Liparidse it was found impossible to determine as to species;
in all, sixteen were taken on all cruises.

13. FAM. PLEURONECTID/E.

'Pleuronectidae do not occur in any great number in the material, with the
exception of Drepanopsetta.. There are, however, on the coasts of America, many
species of flounder whose eggs and larval stages have not been described, that on this
point, more especially as regards the ova, errors may have occurred in the determination.

CAXAitf.w risiiEini.s i:\rr:r>rri()\, nii'i-i-') 17

The larva; recorded under the different species are so like the European that, as
V role, there was no difficulty in deciding; several species, moreover, have been figured.
If we consider, houtner, the insiiiniiicaut nuniher ot unknown ri(nni(ler larva' (of which
part could not he determined owing- to accidents in the preservation) it would hardly
seem likely that any fjivat number of unknown eerss would be liable to confusion with
other species. Of unknown Pleuronectida- tlie followin<i- were taken: —

Ijength.

Acadia station 4, 150 — 0 m 1 I'leuronectes? 5 mm.

38.100 — 0ml " "....'.. 6 "

No. " 33 " station 39, vertical 1 " 4 "

No. "33" station 49, vertical 6 " 6-7-6-7-6-7 "

To these shoidd be added one specimen of 4 mm. lenjith from the Princess station
48; probably belonging to the genus Both.us.

P. limanda ( ?) L.

A quantity of ova of this species was found on the first and second cruises f)f the
Acadia (above the banks off Xova' Scotia and Newfoundland).

At Surface. In Vertical Hauls.

Station 29 5 eggs. 5

30 3 " 8

36 1 "

61 ^ "

62 43 "

80 2 "

82

The diameter of the eggs was about 0-9 mm. and the embryos revealed typical
Pleuronectid characters, though none were so far advanced as to ])ermit of their being
iiscribed with certainty to P. limanda; they undoubtedly belong, however, to a closely
related form.

According to Jordan and Everniann, this species also is stated as apparently not
found off the coasts of North America.

P. microcephalus ('Donoyiin)=MirrosfomiisJ,-itt (Walbaum).

At Acadia station 84, a larva of 6 mm., taken in a surface haul, must be referred
to this species.

P. {Gliiploceplialus) ci/nof/Iossits !>.

(Plate IT, Fig. 11.)

Of this species, the following specimens were taken: —

Princess station 34 — Oblique: 1: ca. 6mm.

" " 49 — Surface: 2 : 8-10 mm.

" " 50 — 40-0 : 1 : 7 mm.

Acadm " 83 — Surface : 4 : 6-8 mm.

There were' thus taken eight larv;e in all, but eggs of this speci&s were not found;
these probably did occur in the samples, but must then in some way have been over-
looked. P. cynoglossus spawns in European waters from ]\lay to September; the ova
have a diameter of 1-07 to 1-26 mm., and are otherwise distinguishable by their slightly
striped structure.

P. cf/noglossus belongs to the North Atlantic; on the American side it extends as
far as cape Cod: lives in comparatively deep water, preferably with sandy bottom.

6551—2

18

DEPARTMENT OF THE NAVAL SERVICE

Ancylopsetta (Notosema sp.)

(Plate II, Fig. 12,)

A specimen of 7 mm. from Acadia station 44 (surface). Belongs to the warm seas.
Drepanopsetta (Hippoglossoides) platessoides (Fabricius).

(Plate II, Figs. 13,14,15; Table Ilf.)

Princess 1 5t.3-26
Acadia I St 2-36 ^^^^

flf^S

Drep a nop 5 e it a

• I - 100 pr Station all hauls
^^more than loo "

81 - 10 pr. Station
more than lo

Fig:. 11.

Pig. 12.

0551—2.1

20

DEl'ARTMEST OF THE yiTAL SERVICE

"33'

%i

Drepanopsetta

i-ioopr Station all hauls
kmore than loo -

Fig. 13.

Eggs and larvjE of Ifrepanopsetta have a wide distribution, especially over the
banks. The ova are very often found together with cod eggs, and were especially
numerous on the first cruises.

June 9 to June 15, Prmcess I gave 609 eggs + 5 larvae.

August 3 to August 12, Princess II " 1 " +7

May 29 to June 4, ^carfia I "1,089 " +7 "

July 21 to July 29, Acadia II " 35 " +28 "

To these should be added the hauls made by the ^o. 33, which contain ova of
Drepanopsetta in considerable quantities until July 10. The spawning time must
thus be regarded as over by middle of July, which is somewhat late in comparison with
the European waters. (In the North sea, spawning taken place from January to
May.) The ova of Drepanopsetta are very easily distinguishable by the large peri-
vitelline cavity, and by their considerable size.

Measurements from the No. S3 station 16 give the following numbers of eggs for
■each size (diameter in mm.) : —

2*1 mm.
2-2 "
2-3 "
2-4 "
3-5 '

1
3
10
4
?

CAXADIAX FISHERIES! EXPKDITIOS, 191Jrl5

21

As will be seen from the above, the diameter A'aries up to 4/10 mm.

Larva? of Drepanopsetta were found especially on the cruises of the Acad'ui and
Princess in July-August; they occur but sparsely, save at stations 81 and 8o (New-
foundland banks), where they were more numerous. The length of the larva- varied
between 5 and 20 mm.

Distinction is made between two forms of Drepanopsetta; D. plabessoides, the
more arctic, which also extends down along the coast of America, and D. Umandoides,
the European form.

Drepanopsetta lives preferably on sandy bottom, on the banks, but can also, at
certain times of the year, move down into the deep water of the channels, where it
then lives on soft bottom.

14. FAM. GADIDJE.

Gadus cvglefinus (Linnaeus).
Gadus callarias (Linnaeus).
Onos sp.

Onos cimhrius (Linnaeus).
Merlnccius merluccius (Linnaeus).

(Plate III, Figs. 16 to 22; TableII<7 to Hi.)

The gadoids play the most important part in the material collected; ova and
young of this family were found in all the areas examined and on all the cruises
made. On consulting the chart, however, it will at once be noticed that the different
species have each their own area of distribution, and only occasionally overlap.

The ova of cod and haddock cannot be distinguished one from another with ful]
certainty in the earlier stages. True, those of the haddock are, as a rule, some tenth.s
of a millimetre larger than those of the cod, but both species vary so greatly as to
overlap in this respect. I have, however, always counted such eggs as could be deter-
mined with certainty (i.e. those with developed embryo) in each sample, on the basis
of which it is justifiable to reckon the proportion between the two species, also as?
regards the earlier stages, at any rate with a considerable degree of exactitude.

DiAMKTEKs in millimetres for Eggs belonging to the genus Oadus, from different

Canadian localities.

May 30.

June 9.

■Tune 11.

•June 15.

August 4.

August 5.

—

" Acadia'" Sta. 6.

"33'
Sta. 10.

"Princess"
Sta. 10.

" Princess"
Sta. 2K.

" Princess" Sta. 31.

"Princess''
Sta. m.

Oadits sp.

G.

*fietilefinus

Gadus sp.

Gadus sp.

Gadus sp.

GmIus sp.

*G. ealf (iritis

Gadus ap.

mm.
1.15

i'

14
23
38
33

8

4

1

4

35

43

44

41

K

1

1

1.20

1
4
7

10
2
1

4

6

7
6
2

1

io'

!)
5

2L

1.25
1.30
1.35
1.40
1.45

6

15

1

4
5
4

21

27

• 18

9.

1.50

* With diagnostic pigmentation of the species.

22

DEPARTMENT OF THE NAVAL SERVICE

As will be seen from the table, the ova of cod and haddock have a diameter of
1-15 to 1-50 mm.; a number of safely determinable cod eggs 1-25 to 1-35, and
haddock eggs 1-30 to 1-45 mm.

With regard to the pigmentation, the larvae of cod should most properly be taken
as belonging to the type described by Schmidt from the southern part of the North
sea ; it may perhaps be designed as a warm-water type, with extremely faint pigment.
Vide fig. 17, and, for comparison, also fig. 16, which shows a more northerly type. As
no larva of this type was available suitable for illustration purposes in the material,
one from Norway has here been used.

On looking through the tables, we find a single haddock egg in the gulf of St.
Lawrence, and no haddock larvse; the material from here can therefore, practically
speaking, be taken as belonging to Gadus rallarms.

Fig. 14.

Fig. 15.

24

DEPABTMEXT OF THE NATAL SERTWE

Gadus

I .•i-ioopr Station all hauls

"^^■'l^^more than 100 •'

Q ' - 10 pr. Station
)more than lo

Fig. 16.

Only ou the cruiacc of the Avadia arose any risk of confusion with haddock,
and here, more especially in the case of the southerly stations, where examples of
haddock ova were in the majority.

The charts show very distinctly the distribution of the cod egg's. We find them
always over the banks, and as a rule in greatest numbers where the banks shelve down,
but never distributed over great depths.

Cod larvae occur very sparsely; only on the ^Newfoundland banks have we at
Station 83 a fairly good yield of 216. the sizes here varving between 3 and 10 mm.
and ranging for the greater part between 4 and 6 mm., i.e., comparatively newly
emerged fry.

Haddock larva; were found only on the cruises of the Acadia, especially the
second, off Nova Scotia and ou the Newfoundland banks. They are very few in
number ; only sixteen for both cruises together. The size varied between 3 and 15 mm.

Cod and haddock have, as we know, a very wide area of distribution in the
northern hemisphere. The haddock ranges from the bay of Biscay as far as Spitz-
bergen; on the American side, Avhere, by the way, it is not so numerous, down to cape
Hatteras.

In Euroi^ean waters, the haddock spawn from January to June.

The cod has more or less the same distribution as the haddock, penetrating,
however, also down into tke Pacific. It spawns at the same time. Spawning has,

CA^ADIAy FISnERIlJS EXPEBITIOW lDl',-irj

25

moreover, been recorded in August on a single bank of the North sea. The spawning
takes place for the most part on the bank^, where the temperature keeps at about 4°
C, and it is generally supposed that the cod, for this reason, move down from the
Polar seas to the southward, in order to spawn en the Norwegian coastal banks about
Lofoten, which are washed by the temi^erate waters of the Gulf Steam, f'od held
in captivity seldom spawn in water below 2° C.

The ppawniiifr in Canadian waters evidently extends over a very loniz jx-riod. On
the first cruises of the Acadia and Princess, May 29 to June 16, free larvae of cod were
found, while on the last cruises, July 21 to August 12, ova were still obtained in early
stages. This is doubtless due to the extraordinary conditions of temi)erature in these
waters.

Of the Onus eggs and larva>, most no doubt, belong to 0. cimhrius, Plate III,
figs. 21 to 22, but as pigmentation, especially of the larvae, varies somew^hat, I could not
feel certain that all belonged to this species. A number of Onos eggs from the Acadia
captures certainly belong to another species.

Onos sp

• i-ioopr Station all hauls

Princess I St 3-26 ^^95(^f„ore than loo .

jrjmore than lo

Fig. 17.

Onos sp.

J. ■ H )^ i-ioopr Station all hauls

Princess n St 27-50 ^i'$'5|0more than 100 ■■

»■ Acadran St 37-91 /-^,L„ i Q ' " '° P^ Station
Z-az-nae ^^rno^g thamo

Fig. 1!

C'ANADIAX FIHHERIEf^ EXPEniTlO\, Wl'rlJ

27

"35'

LarM'ae I ><

; \0

Gnos sp.

I -lOo pr Station all hauls

more than lOo

I - 10 pr Station
more than lo

Kig. ly.

The diameter of the egg's is between OS and 0-9 nun. as regards those from the
gulf of St. Lawrence. At the Acadia Station 47, however, the diameter was 0-70 to
0-75 mm.

Onos cimhrius is widely distributed botla in European and American waters. It
does not, however, ])enetrate so far to the northward as the cod; lives mainly on soft
bottom in fairly deep water, near the coast. It spawns more especially in May
(Europe).

As regards its distribution in the gulf of St. Lawrence we notice that it is
especially numerous about Prince Edward Island and towards Anticosti; always close
to land or above the more shallow banks.

Ova of Merluccins were found in considerable quantities on the second cruise of
the Acadia, especially above the banks off Nova Scotia.

'. Cv+

^\

r^^

\

+

'N

\

+

^

_ +

Mer/L/c/us

I - 100 pr Station all hauls
I more than loo ..

Fig. 20.

CANAhfW FISIIKinr.s IIXI'FJHTIOS, 1<)1>,-15 29

A nuniber of measurements made give the following' results : —

0*90 mm 6 eggs.

0-95 " 28 "

1-00 " 5 "

Merluccius merluccius is not noted in Jordan and Everraann's " Fishes of North
America." The ova, however, certainly agree very well with the European form.
Larvae of this species were not found, l)ut some few eggs in a fairly advanced state
of development.

Of the American forms, M. hilinearis (Mitchill) is the species most closely
resembling the European, and the ova should probably be ascribed to this species.

In European waters, Merluccius is of very common occurrence in the Mediter-
ranean and off the coasts of England; it extends, however, up as far as Xorway and
Iceland.

In the Mediterranean, it spawns in tlie spring months; in the more northerly
waters, during summer.

15. FAM. AMMODl'TID.E.

Ammodytes tohianus (Linnaeus).

(Plate III, Figs. 23 and 24; Tab'.e II j.)

A. tohianus was found in greatest numbers on the first cruise of the Acadia,
eighty-nine specimens being secured.

The second cruise of the Acadia, the cruise of A'o. S3, and the first cruise of the
Princess, furnished together only thirteen specimens; the second cruise of the Prin-
cess, none.

It would seem to be found especially above the banks, but has also occasionally
been encountered over the deep channels, and closer in to land. The length varies
from 7 to 25 mm. the diflPerent sizes apparentlj^ occurring together.

A. tohianus has a wide European area of distributii^i, extending from Spain to
Einmarken, the "White sea, Iceland, and Greenland.

It is probably identical with A. americanus, DeKay, which species, according to
Jordan and Everniann, ranges from Newfoundland to cape Hatteras.

The European form spawns in the autumn at about 20 metres depth, where the
ova are attached to grains of sand.

The eggs may be hatched during the course of the winter; not until spring, how-
ever, are the larvae found in any considerable nuaibers among the plankton, where
they are then often encountered in enormous quantities.

IG. FAM. TETRAGONURIDyE.

Tetragonnrus cvrieri (Risso).

(Plate III. Fig. 25.)

One specimen of this Atlantic species, measuring 76 mm. was taken at Acadia
station 56; (210 to 140 fathoms).

T. cuvieri is especially numerous in the Mediterranean and adjacent portions of
the Atlantic; according to Jordan and Evermann, it has only once previously been
taken oif the coast of America. It keeps chiefly to deep water, feeds on medusae, and
its flesh is s.iid fo be highly poisonous.

30

DEPARTMENT OF THE XAVAL SERVICE

17. FAM. GASTEROSTEID^.

Gasterosteus aculeatus (Linnaeus).
= G. hispinosus (Walbaum).

The three specimens of this species taken would seem to be full-grown, living
pelagically in the neighbourhood of land.

Their total length was 65, 44, and 38 mm. they were taken in surface hauls, at
Princess stations 28 and 2'9, and No. 33 station 13.

G. aculeatus has an extraordinarily wide area of distribution in the northern
hemisphere, and is found down along the coast of America as far as New York. It
also penetrates up into the rivers.

]8. FAM. SALMONID^.

Mallotus villosus (Miiller).

(ipiatie III, Fi'gis. 26 land 27 ; Table II k. )

Fig. 21.

CANADIAy /•7.S7/A7i'//;n hWrEDlTIOX. lOl'rlS 31

This arctic cireuniiwlar species ofteu occurs in great numbers down towards
Finmarken and Newfoundland. Tn North America waters it is found as far down as
cape Cod.

In Norwegian waters, it spawns along the coast from April to June, depositing
its eggs in great (juantities, chiefly on sandy bottom, at depths to about 100 metres.

The newly emerged larva is about 7 mm. long. Of M. viUofiiift, a considerable
number were collected, esi)ecially around the coasts of Newfoundland ; it occurs more
sparsely out towards Labrador and down in the direction of Prince Edward Island.

The size of the larvae varies between 7 and 42 mm.,, the great majority, however,
being between 10 and 20 mm.

19. FAM. STOMIATIDJ^.

Stomias hoa (Eisso).
Cyclothone sp.

Stomias hoa (one specimen of 30 mm. taken at the surface, Acadia station 40) is a
cosmopolite, belonging to the warm seas of the world.

Of Cyclothone, five specimens were taken, ranging from 7 to 16 mm.; these were
not determined as to species.

Two specimens from the surface, 8 to 16 mm. Acadia station 16.

Three specimens, vertical haul, 200 to 0, 7-8 and 10 mm., Acadia station 16.

The genus CyclotJione comprises several bathypelagic species from various warm
and temperate seas of the world.

20. FAM. SCOPE LI DyE.

Scopelus sp.

Omosiidius elongatus (A. Brauer).

Myctophum glaciale (Reinhardt).

M. henc'iti (Cocco).

M. punctatum (Eafinesque).

M. humholdti (Risso).

(TABLE III)

32

DKrARTMEXT OF THE NATAL SERVICE

^

+
-3

+

Princess n St 27-50
Acadia n St 37-91

*>

McllOtU3 [////05U5

/ / O I -10 pi" Station al

^^''^'^^lOrnore than 100 ■. -

Scopelus sp.

hauls

a

more than lOO

Fig. 22.

A large number of Scopelida^ were taken at the outermost Acadia stations. It was
found impossible to determine species in the majority of examples, the preservation
being frequently imperfect. Omosudis elongatus was taken at three of the Acadia
stations.

station 16 200 — 0 m. 2 species 25 to 36 mm.-

57 150 — 50 fms. 1 species 105 mm.

75 ISO — 0 fms. 1 species 45 mm.

This species belongs to the warmer portions of the Atlantic and Pacific.

M. glaciale (one specimen of 15 mm. from Acadiu station 45, 150 to 0 m.) This
species is of common occurrence on the^ east coast of Apierica, but is also found
throught the whole of the i^orth Atlantic. Also taken off the coast of Greenland.

M. henoiti. one specimen, 15 mm., from Acadia station 16 (surface haul). Belongs
chiefly to the warm Atlantic waters ; also penetrating into the Mediterranean.

M. punctatum, one .specimen, 23 mm., from A cadia station 16, 200 — 0 m.

This species has frequently been taken up towards Newfoundland. (A. Brauer.)

M. humholdti, one si>ecimen, 31 mm., from Acadia station 11 (surface haul).

Found in all warm seas

CANADIAX FIRHERIEH EXPEDITIOX, lDl.'ri5 33

III. DISTRIBUTION OF EGCiS AND YOUXG IN THE WATERS

INVESTIGATED.

It is a well-known fact that certain species have their more or less definite
spawning grounds, or, at any rate, are to be found during the spawning season, at
places where certain physical conditions prevail, these conditions being, presumably,
such as are best adapted to the propagation of the species in question.

When spawning, our most important food fish assemble upon grounds of restricted
area, where they can naturnllv be tnkeii in the creatoit iiumber: it i=; therefore of
considerable importance, for the fisheries, to ascertain the position and extent of
such grounds. This may be done by making experimental hauls to secure the spawning
fish, or, far more easily, by plankton hauls, from the results of which it will be seen
where the newly spawned eggs and young are to be found, whence we can determine
the locality of the spawning grounds. This latter method has been largely employed
in the international investigations in European waters, and has led to the charting of
the spawning grounds of the dift'erent species.

If we now consider the results of the various cruises in Canadian waters, it
will soon be seen that the eggs and young of each species have one or more principal
areas of distribution, diminishing in frequency to either side of such area; further,
that certain species generally occur together, others again being invariably found apart.

This distribution is dependent upon the diiferent circumstances under which the
fish spawn, and we shall see that each species is always encountered under certain
conditions, wherefore a certain degree of regularity may be shown to exist in their
occurrence. The eggs and young of littoral fish are found close to land, or over the
shallow banks; the banks have their own particular young-fish fauna, and the deeper
parts, again, theirs. To these must be added a fourth group, to wit, that of the
pelagic species, such as the mackerel; in the case- of these, the question of depth is
less important, and their eggs may therefore be found scattered throughout all areas,
where they may be taken together with the ova of the three first groups. An interesting
phenomenon, however, is the fact that both eggs and young of practically all our
principal species of fish have a pelagic stage, during which they are to be found near
the surface, without regard to whether they were spawned there or at greater depths.
In the case of most species, both eggs and young are so balanced as to float in ordinary
sea- water, and when spawned deep down will, owing to their own buoyancy, rise to
the surface, where their development then proceeds. The young will thereafter, as
their growth advances, again move down to greater depths, or in towards land, passing
from a pelagic habit of life to a more or less pronounced bottom stage.

A. The Gulf of St. Lawrence.

The various cruises furnish a number of instances showing how the character of
the fauna changes as we pass from the vicinity of the coast outwards, or from colder
to warmer waters, and vice versa.

As already mentioned, the gulf St. Lawrence was investigated by the Princess,
June 9 to June 15 and August 3 to August 12, with some occasional work done by the
No. S3 from June 1 to August 18; this latter cruise may be disregarded in the present
chapter, both on account of the length of time covered, and also because the voyage was
not planned according to the special lines of our present purpose. The route followed
on such cruises is, it should be noted, of great importance both for the investigation
of the different localities, and also for the collective survey of the waters as a whole.

The cruises of the Princess (vide chart, p. 4) both proceeded from Prince Edward
Island over to the eastern point of Anticosti, continuing up to Labrador, and thence
eastward to Newfoundland, then following the coast southward, past Cape Breton, and
bade to Prince Edward Island. Glancing now at the hauls inade at the different

6551—3

34 DEPARTMENT OF THE NAVAL SERVICE

stations, we find close to land (Stations 3 and 4) very few larvae; only one or two
specimens of the arctic species Anarrliiclias latifrons and MaUotvs villosus; moving
out over the banks, we encounter DrepanopseUa and Gaclus callarias, with some few
ova of Onos cimbrius, besides some arctic fish, viz., Icelus hicornis and Agonus de-
cagonus. At station 9, near the edge, G. callarias and DrepanopseUa are again less
numerous ; we find, however, instead, the young of Sehastes marinus. Stations 10, 11
and 12 above banks east of Anticosti reveal once more a true bank fauna, Drepanop-
seUa and G. callarias.

Stations 13 and 14, up towards Labrador, furnished but a poor yield; the stations
nearer Newfoundland, however, are a^ain seen to be rich in eggs of DrepanopseUa and
G. callarias, with some few Sebastes in the vicinity of the deeper channels. Here, on
the slope towards Newfoundland, lie the richest stations of the whole cruise; stations
17 and 18, for instance, furnished each over 1,000 cod eggs in surface hauls alone,
besides a considerable number of DrepanopseUa ova. Moving southward along the
coast, the hauls are still rich as regards these species, and at station 19, close in to land,
we encounter, for the first time, ova of the southerly form Ctenolahrus adspersus.
Above tlie deep channel in Cabot Strait, Sebastes predominated. Not until station
24 is reached do we again meet with the banks fauna, G. callarias and DrepanopseUa,
which are thenceforward of common occurrence throughout the remainder of the cruise
back to Prince Edward Island. The last stations, south of Cabot strait, also furnished
quite a respectable yield of newly-spawned mackerel eggs, which was not a little sur-
prising in view of the fact that the hauls made but a few days previously on the
opposite side of Prince Edward Island had yielded nothing but more or less arctic
species.

The August cruise of the Princess (vide chart, p. 4) covered, roughly speaking,
the same ground as the first. Close m to land, the yield consisted mainly of eggs and
young of Onos and Ctenolahrus, until we reach the banks, when cod and mackerel
make their appearance. These latter increased in numbers as the outward voyage pro-
ceeded, the Onos and Ctenolahrus gradually disappearing. Above the deep channel,
Sebastes predominates; some few mackerel larvae were also found. On the Anticosti
bank, we find cod eggs once more, and the same alternation of cod above the banks,
Sebastes over the channels, is continued all the rest of the way to Newfoundland, and
thence southward to Prince Edward Island. Station 45, however, near the southwest
point of Newfoundland, also furnished a rich yield of the arctic species Mallotiis
villosus, evidently indicating the existence of a cold current near at hand; on the
southern side of Cabot strait, however, eggs of mackerel and Ctenolabrxis were again
encountered.

As will be seen from the foregoing, the gulf of St. Lawrence may be divided up
into several zones, each with its own characteristic young-fish fauna. In the first
place, a line drawn from Cabot strait to Anticosti will form the northern limit of
occurence for the southern forms found in the gulf, such as mackerel, Onos and Cteno-
lahrus. Only at one or two of the more southerly stations situated near the coast of
Newfoundland were some few specimens of these species found.

Northern species, however, may also be found south of this line, occurring more
particularly in the southwestern portion of the gulf, ^ west of the Magdalen islands.
For the rest, the character of the young fauna varies with^ the depth; we find Ctenola-
brus and Onos near land, and close to quite shallow banks, tlie bank forms consisting
fo G. callarias and DrepanopseUa, while above the deep channels Sebastes is found.
The mackerel, again, is encountered throughout all areas, subject to the restriction
noted above.

B. The waters orxsroE Nova Scotia axd the Newfoundland Banks.

The cruises of the Acadia (vide chart, p. 4) reveal a similar grouping of the
different species, according to depth, distance from land, and geographical position.

VAyADIAy FI.^HKRIi:s EXPEDlTIOy, lOJJf-lS 35

Ou the May cruise, the stations from Halifax out over the banks past Sable
island yielded eprprs of cod and haddock, several species of flounder, Animodiites, and
a very small number of Ctenolahrus above the shallower prounds near Sable island.
Outside the banks we find Sehastes, but farther out again the yield becomes extremely
poor until the outermost station (station IGj, where a number of pelagic Atlantic
forms were found. On reaching the Newfoundland banks, we find once more cod,
Drepanopsetta and Ammodijtes; above the deeper portions towards Cape Breton and
Cabot strait, Sehastes is of more or less frequent occurrence.

Tlie second cruise of the Acadia shows small yields at the start, off the southern
point of Xova Scotia; strangely enough, however, we here find Sehastes at comparatively
slight depths. This is probably connected with the fact that Sehastes in these southern
waters (Bay of Fundy and Xew England waters) spawns in more or less shallow water.
On the slopes, where the depth increases, we find numerous eggs of Merluccius;
farther out, the Scoi)elida^ play a more prominent part. Ova of cod and haddock
are now but sparsely found at all stations outside Nova Scotia ; on the Newfoundland
banks, however, they are once more encountered in great ninnbers, stations 81 to S.3
being particularly rich. Eggs of Drepanopsetia also are fairly numerous here, while
the arctic capelin bears witness to the vicinity of the polar current. From the banks
over to Cape Breton, Sehastes is again more frequently found, Onos (hardly however,
Onos cimhrius) only in very small quantities, Ctenolahrus only at station 91, quite
close to land. We see, then, that in this area, likewise, distinction may be made
between several different kinds of fauna. Up towards Newfoundland, we have —
according to European terms- — eggs and young of boreo-arctic fish, on the banks off
Nova Scotia a boreal bank fauna, while out over the great depths, especially to the
sovithward. the Atlantic species predominate.

On comparing the stock of young in these two areas; the gulf, and the waters
outside Nova Scotia, we find that the gulf should most properly be regarded as a
coastal water, where littoral and coastal forms are found in great numbers; we find
the usual high degree of variation in temperature between summer and winter, with
corresponding variation in the fauna between northern and southern forms; purely
Atlantic species, however, do not appear in the hauls.

An interesting feature, by the wav, is the fact that the mackerel is not represented
at all in the Acadia material (but few eggs on the first cruise); while the greater
portion of the Ammodytes taken during the investigations was furnished by the
Acadia. It is remarkable also, that none of the cruises furnished a single herring larva,
despite the fact that the herring occurs in nearly every part of the areas investigated.

IV. BIOLOGICAL CONDITIONS.

Modern marine research has shown us that life in the sea is to a high degree
dependant upon hydrographical conditions: current, temperature, and salinity. We
should, therefore, in seeking to explain the peculiar phenomena encountered with
regard to the propagation of the fish in Canadian waters, base such endeavours
upon tlie liydrographical data furnished by the ex]>editron. These are, however, not
yet compiled, in order and completeness, and we must for the present content ourselves
with recalling the more prominent features. It will be obvious from the outset that
an area subjected to such markedly contrasted influences as those of the Labrador cur-
rent and the Gulf Stream must present many remarkable features both as regards
fauna and biology, and it is only by bearing in mind the peculiar hydrographical con-
ditions that we can explain the otherwise surprising data furnished by the Canadian
Hydrographical Expedition wifli re.o-ard to the propn<rnt.ion of tlie most important
species. On comparing the Canadian with the European waters in this respect,
several peculiarities will at once be noticed, especially the pronoimced transposition
and extension of the spawning season, which here takes place in the case of several

6.551— 3*

36 DEPARTMENT OF THE NAVAL SERVICE

species, among those pre-eminently which on the eastern side of the Atlantic are
counted as spring-spawners. A prominent example is that of the cod (in addition
to haddock and JJrepanopsetta) which spawns in considerable numbers in the gulf of
St. Lawrence right on into the month of August, whereas in the Norwegian waters,
its spawning- is over in May. As a consequence of this, we may, in the gulf of St.
Lawrence, iind one and the same plankton haul to contain both newly-spawned cod
eggs and newly-hatched mackerel young.

That cod and mackerel should find suitable spawning conditions in the same
water and at the same time is remarkable indeed; in European waters, the spawninjj
of these two species differs widely, both as regards time and place. What is more, it
is only exceptionally that the mackerel come so far north as to touch the principal
spawning grounds of the cod at all. The explanation may not unnaturally be imagined
to lie in the abrupt changes of temperature encountered in the Canadian waters. The
same natural conditions which cause Atlantic warm-water forms to meet, off the
coasts of Newfoundland, with representatives of the arctic fauna, might well account
for the fact that in the gulf of St. Lawrence, the cod of the far north are able to
live and propagate there simultaneously with the more southerly mackerel. If we
take a temperature series from the surface downwards in the gulf of St. Lawrence
during summer, we find, within a vertical range of less than 100 metres, a difference
in temperature equivalent to that encountered outside Newfoundland by sailing from
the Gulf Stream over into the Labrador current, while on the eastern side of the
Atlantic, such difference will involve a distance as from the North Sea to Spitzbergen.

In the gulf St. Lawrence, then, we find the different water layers varying so greatly
in temperature as to afford favourable conditions both for cod and mackerel. That
both species should live in the same stratum . there is no reason to believe; on the
contrary, it must be presumed either that the fish are themselves able to seek out the
more suitable water layers, and avoid those less favourable, or that they are, owing
to certain biological features, more or less passively led to frequent such strata as
are by nature best adapted to their needs.

It is a well-known fact that certain species of fish, such as cod, herring, and
mackerel, vary their habitat according to the temperature of the water. Cod and
herring may at times move in shallow, at others in deeper, water, and in the southern
Norwegian waters the mackerel seems rarely to move in towards the coast until the
surface temperature is at about 10° C, a fact so generally recognized that some of the
drift-net fishermen even carry a thermometer in order to make sure of not laying out
their nets in a cold current.

Among the biological features which might be thought to act in this direction,
we should first of all remember that the cod is a bottom fish, belonging essentially to
the strata nearest the sea floor, where its food is found, and where its spawning takes
place. The mackerel, on the other hand, is a pelagic species, frequenting — at any rate
during the spawning season — the upper-water layers. Indeed, until the roe is spent,
the mackerel hardly seems able to penetrate down beyond some 20 metres depth.

On glancing at a temperature series from the Princess station 30, where ova of
cod and mackerel were found in one and the same sample, the phenomenon will easily
be explained.

Om t= le-l" ot = 20-27

10 " IS-T" 20-33

25 •' 10-S" 21-97

4n " 7-9" 22-99

50 " ; .. 5-65° 23-97

fiO " 0-45° 25-40

If we now apply to these figures what we know of the biology of the cod and
mackerel, it will be justifiable to conclude that the mackerel keep to the upper layers —
down to about 25 m. — where the temperature is favourable to its needs, -while the cod
seek the lower strata, finding there more suitable conditions in this respect.

CA^ APIAN FISHERIES EXPEDITION, 19Vrlo 37

The yield of cod and mackerel eggs at this station gives the following numbers: —

Cod. Mackerel.

At surface. 3 eggs. 172 eggs, 14 larvae.

*• 30-0 metres 12 " 8 " 3 "

" CO-0 " 25 " 1 "

Mackerel eggs and young are by far most numerous at the surface (in the horizon-
tal hauls) the cod eggs, on the other hand, being found in greatest numbers farther
down (vertical hauls). Naturally, however, this cannot be taken as indicating that
the mackerel eggs were spawned near the surface, and the cod eggs lower down. The
vertical position of fish ova in the layers is determined by the specific gravity of the
former as compared with that of the ^vater, and they will, under normal conditions, be
found in water of specific gravity equal to their own. The specific gravity of ova,
however, is not a constant magnitude; that of cod eggs, for instance, which normally
varies but very slightly, may be affected by a low degree of salinity in the water, which
has the effect of gradually reducing the weight of the eggs. If exposed to strong sun-
light, again, or to comparatively high temperature, they will sink, even in water of
high salinity; and the same applies to newly hatched young. This last is a very well-
known phenomenon in marine hatcheries; I am, how'ever, unable to give any definite
figures, having had no opportunity this season of making experiments in this direction.

The specific gravity — and variation of same — in cod eggs at Flodevigen will be
seen from the following experiments (Dahl & Dannevig; Undersokelser over nytten
av Torskutlsekningi Ostlandske fjorde, Bil. I, p. 28).

The roe and young were placed in three separate receptacles in order to determine
their approximate specific gravity.

I. Sp. gr. 1019 at + 5-4° (sp. gr. in situ, 101796).

Ova, about one-third floating, others suspended, the remainder at the bottom.
1 oung, most at bottom, some suspended and at surface.

II. Sp. gr. 1-020 at + 5-4:° (sp. gr. m situ, 1-01897).

Ova, more than half floating, the remainder at the bottom or suspended.
1 ou7ig, about half floating, the rest at bottom or in suspension.

III. Sp. gr. 1-022 at + 5-4° (sp. gr. in situ, 1-020965).
Ova, practically all floating.
Young, practically all floating.

Station 30, above-mentioned, the specific gravity of the water near tlie surface
oscillates about the value for specific gravity of cod egg^ as noted in Norway : we
might therefore have expected to find a greater number of ova at the surface. That
this was not the case should possibly be ascribed to the influence of the high tempera-
tures there prevailing.

^Ve find, then, that the simultaneous spawning of cod and mackerel in one and
the same water may be explained as due to conditions of temperature. And conse-
quently, we cannot, in Canadian waters, distinguish between winter and spring-spaw-
ning fish, as is generally done in Europe; if any such biological distinction is to be
made, it must be based upon the limits of temperature between which spawning takes
place, a method which would of course be equally justifiable on the eastern side of the
Atlantic.

The question arises, however, whether the temperature of the water really does
exert such influence upon the spawning of the fish; whether other causes might not
be imagined, and the explanation above suggested be found insufficient.

In this connection, it will be natural to recall the annual periodicity in the
development of the sexual organs, which might be supposed to proceed independently
of all extf^rnal factors. It has, hovever, repeatedly been found, by investigation in

38

DEPARTMENT OF THE NAVAL SERVICE

other spheres, that where regularity of the seasonally varying physical conditions in
animals or plants ceases, the annual period disappears, or becomes irregular and
indistinct.

The influence of temperature upon the daily intensity of the spawning ma.-v
easily be observed in a hatchery, at any rate whei-e a spawning basin is employed.
Also the degree to which spawning depends upon temperature is in particular most
easily noticeable where the latter factor ranges beween 0° and + 5°, to a lesser extent
-when between + 5° and + 10°. Other influences may make themselves felt, as for
instance of the amount and more or less regular distribution of the food, the fish
spawning largely when well fed. This may, however, ix)ssibly be due to purely phy-
sical conditions, at any rate, as long as the amount of food consumed is sufficient for
nourishment, as the expansion of the stomach will exert a pressure vipon the ovaries.
Furthermore, the salinity of the water may be supposed to have some effect though
this will scarcely be of any importance as long as the variation involved is not too
great.

■ Temperature centigrade]
- Eggs in liters

2% 2Ji ys % '^3 % =% ^i 54 » '5^

Fig. 23.

The curves here shown are based upon daily observations at the hatchery of
Flodevigen during the spring of 1909, and indicate the fluctuations in temperature
and spawning throughout the essential part of the spawning time. In order to present
the clearest possible survey, I have here marked off, not the daily values, w-hich vary
considerably, but a mean value calculated each day from the observations of that date
plus those of the two previous and the two subsequent days, i.e. a movable mean extend-
ing over five days.

"V. — Possibilities of development, axd relative fkequexcv of the different stages.

In the foregoing chapters, we have dealt with the spawning of the different
species in relation to depth, temperature and season. It now remains to consider how
the development of the eggs in the separate species takes place, and what chances
there are for their being hatched.

From the figures in table II, we obtain the following numbers of eggs and larva?

for the six most commonly occurring species : —

Ova. Twarvse.

Ctenolabrus ' 434 318

Scomber 5,575 47

Drepanopsetta 2,369 47

Gadus callarias and G. a-rjlefinn^ 15.988 293

Onos 2,975 92

Merluccius 8,8 21 0

It will be seen that the gadoids here predominate, and among these, as we have
already seen, the cod is of most frequent occurrence. Ova of Merluccius are also very

CAyADIAX FlHHi:RlEH i:.\ I'i:iHTIO\. 191 ',-13 39

numerous, but the material of these is of a somewhat casual character, being derived
from ouly a few stations, where they must, however, have been present iu great num-
bers.

The proportion between ova and young varies greatly; in the case of Ctenolahrus,
we have nearly as many larvae as eggs while of Merluccius, on the other hand, only eggs
were found.

Such a table cannot, however, be used without reserve as a means of calculating
the percentage hatched for the different species; the period of time required for deve-
lopment of the ova will need to be taken into consideration, as also the age of the
young when captured. With most species it is true these points are insufficiently
known, but in the case of the cod we have knowledge sufficient for a satisfactory dis-
cussion of the question despite the difficulties involved in following the development
of ova under natural conditions.

We know, of course, that the destruction of cod eggs and of the early stages of
young must be enormous ; were this not so, the sea would soon become over-populated
with cod. As to the particular stage of development at which the germ is specially
liable to destruction, however, we know, unfortunately, all too little.

Professor Apstein has, in his work entitled "Die Verbreiting der pelagischen
Fischeier und Larven in der Beltsee und den angrenzenden ^leeresteilen," 1908-09,
dealt with these questions, and calculated that 72 cod eggs are required to produce one
larva. This applies, of course, only to the waters investigated by him, and similarly,
here only for a single year.

THE CAXADIAX WATERS.

During the actual collection of the material. Dr. Hjort already noticed that there
was a very great majority of newly spawned eggs, the later stages of development, and
the larvae, being- far more rare. This was especially noticeable on the cruises of the
Pnncess. Wishing to go closely into this question, I have, in determining the ova,
noted throughout the number of eggs belonging to earlier and later stages; in the
smaller samples all the ova were examined, in the case of the larger, only a represent-
ative portion was measured off and investigated, the figures thus obtained being then
utilized for calculation of values for the whole.

In order to keep the work within a reasonable scope, distinction has here been
made between three stages only; the first being the '' germinative disc" stage, before
the formation of the embryo (figs. 1-2), the second from the early pigmented embryo
to well-developed pigmentation (figs. 3-4), and the third with pigmentation character-
istic of the species (figs. 5-6). These stages correspond to Apstein's figs. 1-0, 10-18
and 19-22, from which these text figures have been taken.

40

DEPARTMENT OF TEE NATAL SERVICE

EiiBRYOxic Development of Egg of Cod.

This system of division is based on no other principle than that of obtaining, as
easily as possible, a survey of the numerical values at the different stages, these last
being so selected as to be distinguishable with no great difficulty when slightly
magnified, and without regard to ^\hether one stage may be of longer duration than
another.

Apstein's tables show, for instance, that my "germinative disc" stage embraces
31 per cent of the total period of development in the ovum; stage 11, 46 -per cent, and
stage III, only 23 per cent.

Taking the material consisting of cod eggs from the cruises of the Princess we
find, for all hauls made, the following figures : —

First cruise. Second cruise.

Stage 1 4.315 1,391

II 799 340

III 13 33

Larvse 6 6

We find then, on both cruises, an overwhelming majority of ova in the early
stages. How is this to be explained? Is it to be taken as entirely due to mortality or
destruction by some means, or do other factors here exert their influence, rendering
the immediate impression produced by the above incorrect?

As we shall see, a table of this sort should be treated with the greatest caution.
The proportion between the different stages is not only dependent, for instance, upon
mortality, but also to a high degree upon the time at which the investigations were
made; in addition to which, we have also to consider the position of the stations
in relation to the spawning grounds.

'When the investigations are carried out early in the spawning season, then
naturally there will be a very high percentage of newly-spawned ova, and no late
stages. Investigations later in the season, on the other hand, will give the opposite
result.

A few rich hauls made on the exact spot where spawning takes place wi)l give
a different result to that obtained from hauls made out over the greater depths where

CAN Am AX FISHERIES EXPEniriOy, 191 'rJo

41

the fish do not spawn; tho few eggcs, found outside the banks, will have been carried
thither by the current, and the longer they have been adrift since leaving the spawning
grounds, the farther will their development have advanced. On the spawning grounds,
therefore, we must expect to find newly-spawned eggs in the majority; outside these
localities, the later stages will predominate.

The investigations in the gulf of St. Lawrence are, however, to a very great
extent free from these sources of error. It will be seen from the table that the
spawning was in full progress during the first cruise of the Princess in June, and that
so few late stages were found, may be explained as due to the fact of the hauls in
question being made comparatively early in the season. On the August cruise of the
Princess, however, this objection is no longer valid; the number of ova has greatly
decreased, the season being now-nearing its close, and a far greater quantity of eggs
in the later stages might have been expected.

'On going through the tables for the cruises of the Princess it will further be
noticed that the proportion between newly-spaAvned ova and those in the later stages
is approximately the same at all stations, only exceptionally do we find the later stages
in the majority. No single station is so rich in newly-spawned ova as to exert a
dominant influence upon the result as a whole, and there is thus no reason to question
the representative value of the material on this head.

As regards the number of larvae, this will always be subject to considerable
error, as the larvae are more or less endowed with power of motion, rendering capture
more difficult, in addition to which, their age is often difficult to determine. Com-
parison between ova and young will therefore be subject to greater uncertainty than
that between ova at different stages.

One thing we can, however, state with certainty : that the number of larvae taken
in the gulf of St. Lawrence was remarkably small.

In the case of the Acadia, the proportion between the different stages is somewhat
better; here, however, we must consider cod and haddock togeliier as one, these two
species being indistinguishable one from another in the early stages of the ova.

Stiigel

Stage II

/ cod

I haddock ....

Lar'

Aeadia II.

\-= 72
= 275

For these cruises, the results are as might have been expected, the May cruise
showing a comparatively large number early stages, with some advanced and a few
larvae, while that of Jvdy has many later stages and still more larvae.

Before proceeding to consider the possible explanation of this great difference
between the occurrence of early and later stages in the gulf of St. Lawrence, it may
be of interest to compare the conditions in Canadian waters with those observed on the
principal spawning grounds of the cod in European waters, viz. : —

LOFOTEN.

The material upon which the following discussion will be based consists of but a
few samples from the otherwise extensive mass of material collected by Dr. Hjort
during the winter and spring of 1913, the remainder having not yet been completely
depth with as regards the stage of development of the ova. (Vide also Johan Hjort:
Fhictuations in the great Fisheries of Northern Europe.)

42

nEPARTMENT OF THE NATAL SERVICE

These investigations, besides rendering possible a comparison between the wastage
per cent in the two waters, further afford an excellent illustration of what has been
mentioned in the foregoing as regards the extent to which the respective numerical
value of the different stages depends on time and place of sampling.^

Number of cod eggs pr s
minutes haut indicated at
each station. ^'A-^^ 1915

rtlLOMCTEO

GEOGR MILES (KunRrMIll

Fig. 25.

By way of illustrating these conditiuns under varying circumstances, I have chosen
a section across the Vestfjord, as marked on the chart, and as the surface hauls (1 m.
net, 5 min.) give the greatest amount of material, I have employed these only.

Six stations are noted on the chart, all from April 23 to April 24, 1913, the total
number of cod eggs per 5 mins. surface haul being appended in each case. It will be
noticed that station 65, on the edge, has a pronounced maximum, with 9,800 eggs in
a single haul, after which the number rapidly decreases to either side, as we leave the
spot where the principal spawning presumably took place. During the actual investi-
gations it was frequently noted that the greatest numbers of eggs were taken on the
fishing grounds themselves, where the fish were most densely congregated. The
number diminishes gradually right over towards station 61, on reaching which we
again find ourselves near the edge. Here we might thus again have expected to find
a maximum ; as a matter of fact, however, there was evidently very little spawning, if
any, on these grounds. The banks here, by the way, are of very restricted extent, the
bottom sloping abruptly down from land to a great depth.

With regard to the proportion between the different stages at each of these stations,
we find the following figures (per cent) : —

station 64. Station 63. Station 66. Station 63. Station 62. Station 61.

1 25 6.3 32 30 40 28

II r.5 30 53 57 30 46

III 20 7 15 13 30 26

From this it will be seen that the earliest egg stages are found in the highest
proportion at the very places where the total number was greatest; the more advanced

1 The inve.stigia.tions extejirled tihrooiglhiout t'be whole of the spawning- seaoon, oomprising- alsio
both the bank grounls and the greater depths. The same places were, moreover, investigated
several times during the season, partly with the closing net, and partly with an ordinary sur-
face net.

CAXADIAX FISiHERIES EXPEDITION, 191 ',-13

43

stages, on the other hand, heing of great relative frequency as the distance froni the
spawning grounds increases.

Geirriinative disk
Cod eggs in late stages

Vo
60

50
40
50
20
10

5t. 64 65 66 63 62 61

Total numbeK: 4050 9800 1384 184 105 89

Fig. 2G.

Station G2 differs slightly from the remainder, inasmuch as we here find a greater
number of newly spawned eggs than was to be expected. Evidently, the current must
have brought down the newly spawned ^gs from the banks southwest of the station.
The current at this spot can at times be very strong, and in this very direction. The
numbers, however, both at stations 62 and 61, are not sufficiently great to furnish an
exact picture of the stock there.

The curve for the later stages (III) shows throughout what might theoretically
have been expected, the later stages themselves being proportionately fewest where
most eggs were found. The curve rises as we move away from the spawning banks,
as far as station 62, falling again over towards the land, thus indicating that we are
once more approaching grounds where, in some slight degree, spawning takes place.

As we have seen, the proportion between the different stages varies greatly at
different places, even for samples taken on one and the same day; the variation is,
however, sufficiently regular to permit of our forming some opinion as to the cause.
The example here shown is taken from a locality where the contrast is marked; great
quantities of cod spawning within a restricted area, close to the very deep water
where cod never spawn, but in which a certain quantity of eggs may be found, having
been carried thither by the current. A different state of things would necessarily be
encountered where the spawning takes place sparsely over areas of wide extent, espe-
cially if forming part of a restricted region of sea; at such places, there would never
be the great difference between the relative frequency of the stages at the various
stations.

Stations 64-65 and ()6 were also previously investigated, viz.: 25 '2-12 '?> and 29/3.
Not until the last-mentioned date however, were cod eggs found in great numbers; the
principal spawning was then just commencing. At these three stations (30-31-32)
(29/3) we find the following yield for the different stages (here stated in %).

No. I. II. III.

station .30 (=Station64) 23.600 93% 7% 0

Station 31 (zzStation 65) 19.400 50% 50% 0

Station 32 (=Station66) 2.340 25% 75% 0

The principal spawning this time takes place farther in on the banks; we find,
however, again the same feature as before noted; where the eggs are found in

44

DEPARTMENT OF TEE NATAL SERVICE

greatest numbers, there also the number of those newly-spawned is at a maximum, its
minimum falling there where the yield as a whole is poorest. We notice, moreover,
that advanced stages are not yet present in the samples, this being doubtless due to
the fact that the season is only just commencing.

If we now consider the results from Canada in conjunction with this sample from
the Lofoten material, we obtain a table for comparison of the stages of development
in the eggs from the different waters.

Stage I . .
Stage IT.
Stage IIT

Lofoten

"^"3

23-24^

a>

«

0

cS

s

•^

rn

rj-j

(12%

38%

0%

4«%
40%
12%,

Acadia I

43%

2%

35%

49%
16%

Fri

a

St%

16%

0%

>

86%
13%

1%

Acadia II

52%
35%
13%.

6S%

2!)%

3%

Princess II

64%
32%

4%

«4%

15%

1%

"33'

03

!'5%
5%
0%

83%
14%

3%

From this it will be seen that the gulf of St. Lawrence is considerably behind the
other localities with respect to the occurrence of later stages, both in the case of the
earlier investigation and those made subsequently (Princess I, Princess II, and
iV 0. 33). The ova have here evidently a far poorer chance of being developed and
hatched than in the other places; in the gulf of St. Lawrence the eggs must — at any
rate occasionally — be liable to a high degree of mortality, either due to the hydrogra-
phical conditions or to their being preyed upon with unusual intensity.

The task of solving this question must be left to fjiture investigations; I may,
howeven, in conclusion, set forth such material as we have available for the considera-
tion of what factors should be regarded as detrimental to the development of cod eggs
and the growth of the young.

VI. — I^FLUE^cE OF Temperature and Salinity upon the Development of Eggs and

Growth of the Young.

In order to ascertain what effect the low bottom temperatures might possibly have
upon the development of the ova in the gulf of St. Lawrence, Dr. Hjort approached
Dr. Johansen and Dr. Ivrogh, of Copenhagen, who had previously at the Zoo-physiolo-
gical Laboratory there, carried out a whole series of experiments with hatching of
eggs at constant temperatures, with the request that they would repeat their investi-
gations having the special object at present in view.

We are aware that cod in the gulf of St. Lawrence spa%vn near the bottom, i.e. in
water frequently below 0° ; the inherent upward tendency of the ova then lifts them
to the water layers above, where they develop at considerably higher temperatures.

Dr. Johansen and Dr. Krogh then cemmenced experiments with fertilization of
ova at low temperatures, from 0° to -^ 2° C, the eggs being thereafter either main-
tained at various low temperatures or gradually transferred to warmer water, vip to
6.6° C.

According to Dr. Johansen, the resiilts showed : —

1. That fertilization can take place at a temperature between-=-0-6° and
-^2 = C.

2. That full development can be obtained by ova fertilized at such temper-
ature and thereafter exposed for nine days to a temperature between -;- 0-7° C.
and -4- 1-4. mean value -h 1°, and afterwards transferred to warmer water
(e.g. 0° to 3.3° C.)

3. That full development can be attained by ova fertilized at 0° C. and
constantly kppt in water at that temperature.

CANAblAS FlsHKRlf-Js EXPElJlTlOS, lOl'rlS 45

The mortality observed in the course of these experiments was considerable;
as, however, these were carried out under conditions which in several respects must
be less favourable than those prevailing in the sea, we should not, as Dr. Johansen also
points out, attach too much weight to this. Even at the most favourable temperatures,
the mortality was, in the apparatus employed by Dr. Johansen and Dr. Krogh, still
considerable.

Dr. Johansen's experiments show, however, that the low temperature at the
bottom in the gulf of St. Lawrence where the cod are to be found during spawning
time, cannot be regarded as a general hindrance to the development and hatching of
the ova.

With regard to the influence of high temperatures upon the development of the
ova, we may refer to the experiments previously made bj' Johansen and Krogh
(The Influence of Temperature and certain other Factors upon the Rate of Develop-
ment of the Eggs of Fishes; Publications de Circonstance Xo. 08). These show that
cod eggs may be hatched in water up to 12° C. H. C. Dannevig (late Director of
Fisheries for Australia) has even hatched them in water at 14° C, (Scottish Fishery
Board, 13th Report for 1891.)

At Flodevigen, where several hundred million cod eggs are annually hatched, low
temperatures (down to 0° C. ; the lowest figure at which we have worked) never seem
to have any detrimental effect; the most favourable temperature would seem to be
about 3°-5° C, while temperatures up to 8° or 10° occasion a higher degree of mortality.
As the quantity of ova in the apparatus is very great, the direct cause of such mortality
might possibly be lack of oxygen, or poisoning, despite the fact that the water is
constantly renewed.

That the young can thrive at considerably higher temperatures in a greater mass
of water is shown by an experiment which I made in the culture basin at Flodevigen
during May and June, 1909. The basin is situated in the open air; it measures 34 by
22 by 5 m. and is used in the hatching oi^erations as a water reservoir for the apparatus.
It is supplied with sea water by means of a steam pump, and in order that the water
may be constantly renewed, as well as for other reasons, the water for the hatching
apparatus is always drawn from here.

On the 25th of May, when the hatching experiments were brought to a close, and
the circulation of the water consequently ceased, about 100,000 young cod, from one to
two days old, were liberated in the basin. The eggs from which these young were
hatched had been spawned at about 7° C, and the development had taken place in
the course of about nine days at temperatures between 7-6° and 9*5° C. At the time
of liberation, the water in the basin at 3 m. depth had a specific gravity of 1-026 at
9-5° C. The young could now be seen every day in the water, at first near the surface,
and later swimming for the most part in great shoals in the intermediate water layers.

On the 16th of June, I noted in my journal that up to fifty young could be
counted at one time. On that day also, feeding was commenced with finely chopped
Mytilus edulis. The water in the basin, by the way, was extremely rich in plankton,
especially larvae of molluscs and crustaceans, which, with some few copepods. made up
the stomach contents in such ofi the young fish as were examiAed. On the same
day, the water in the basin had reached a temperature of 20° O. at the surface, with
a maximum, at 1 m. of 21-4° C, and a bottom temperature of 21-1^ C.

On the ISth of June, eight fish were taken up and measured; they showed the
following lengths : 25, 25, 27, 24, 24, 23, 23, 22 mm. The fish were by this time moving
nearer the bottom.

The weather now set in colder for a time, with cloudy sky, and the temperature
of the water sank somewhat. On the morning of the 21st, the surface showed 18-9°
C. ; maximum of 19-5° at 2 m. On that day, fresh sea water was pumped in (tem-
perature 8-3° C.) and in the evening, after the surface water had been drawn oil, and
replaced h^ a new supply, the surface temperature was 19 -4". this being the maximum,
while at 3 •4m. a minimum of 15-7° C. was recorded.

46

DEPARTMENT OF THE J^'ATAL SERVICE

On the 29th June, pumping was renewed, but as the young were considerably
fewer, (and always at the bottom), the experiment was brought to a close. The tem-
perature of the air had, during the last part of the time, been very high, with sun-
shine and slight wind.

This experiment shows therefore that the young can thrive — and even grow very
rapidly — at temperatures up to 20°. The increment of growth from May 25, when the
length was 3 to 4 mm. until June IS, amounts to about 20 mm. or about 0-8 mm. per
day.

From the measurements available for growth of young in a free state, the latter
would seem to grow less rapidly, presumably about 0-5 mm. per day.

Among other causes which might be imagined as affecting the development of
ova, we may reckon the salinity of the water.

If cod spawn in water of lower salinity than that which corresponds to the specific
gravity of the eggs, then these latter will necessarily sink to the bottom and be des-
troyed. And again, if eggs should by any means be transferred from water of their
own sx>ecific gravity to considerably fresher water, the mortality here likewise would
be very great.

As an illustration of the manner in which fresh water can affect the ova, the
following data from an experiment which I carried out in March, 1909, at the hatchery
may be quoted.

About twelve hours after fertilization, eggs were distributed in four glasses con-
taining water of different siieeific gravity, and at approximately the same temperature.
The glasses were placed in a cold room — temperature of air about 0° C. The water
was not changed, only aerated from time to time with a large pipette.

The cleavage and the development generally were observed under the microscope.
After the lapse of twenty hours some samples were taken and transferred to fresh sea
water in order to ascertain whether the development could there proceed normally.

In the case of sample IV, this was repeatedly done.

The result of the experiment will be seen from the following table: —

1909.

Number

of

hoiirs.

I
Sp. Gr. 1 0247
T. 2-2"C.

II

Sp. Gr. 1020
T. 2 (TC.

Ill

Sp.Gr. 1015
T. 1-8

IV

Sp.Gr. ICIO
T. IG

March 19, 2 p.m

7 p.m

10 p.m

March 20, 10 a.m. . . .

M 21, 10 a.m

„ 23, 4 p.m

,t 24. 10 a.m

0

5

8

20

44

98

IK)

All alive .

All alive

All alive

All alive . . .

Devel()|)ment

often abnormal
Some dead.
More dead.
Few alive.

A similar experiment with newly hatched young in water of: —

I Sp. gr. 1-0242 at T = 2-0°C.

II " 1-020 " 2-2 "

III " 1-015 " 2-5 "

IV " 1-010 " 2-5 "

V " I'OOS " 2-7 "

gave the following results: —

I. All the young suspended; after the lapse of an hour some few at the bottom,
after four hours the majority near bottom, but all living. After the lapse of 103
hours, some few were dead, but the remainder stood out well until the experiment was
concluded after 148 hours.

CANADlAy FISHERIES EXPEniTIOy, VJl'rir,

47

II. All oil the bottom by the end of an hour, some endeavouring to rise. Same
course as previous sample, only slight mortality after eighty hours, until about half
died by the end of 142 hours.

III. Some few suspended after a quarter of an hour, but at the end of an hour all
at the bottom. Some few died after the lapse of fourty-six hours, mortality then increas-
ing rapidly until all were dead by the end of 138 hours.

IV. All on the bottom after a quarter of an hour, some trying to work upwards.
Some few died after four hours, more after twelve hours, the remainder with irregular
pulsation of the heart. After thirty hours, many dead, and by the end of fifty-two
hours from the commencement, none were left alive.

V. Some few died in the course of the first seven hours, and all within thirty-four
hours from the start.

From the result of these experiments we may be justified in supposing that a stay
of any duration in brackish water will be detrimental to eggs and young; this will,
however, only occur under quite peculiar conditions, and can be of no importance with
regard to the open sea.

Other factors which might be supposed to have some effect upon the development
of the ova are: lack of fertilization, action of bacteria, and internal causes (natural
death).

Prof. Apstein has, in his investigations in the Belt Sea and the western Baltic,
shown that considerable quantities of dead — or as he considers, unfertilized — ova occur
in the plankton samples. In his work above quoted, " Die Yerbreitung der pelagischen
Fischeier und Larven in der Beltsee und den angrenzenden Meeresteilen 190S-09," we
find the following table for dead ova (p. 231) : —

Per cent dead.

Pleuronectes
platessa.

PI. flesus.

PI. limanda.

Gadus
callarias.

Clupea
sprattus.

Vertical

35

38-5

20-6

219
41

19 '8

27 7

3 7

170

1T3

29

12-7

12 8

31-7
49 6
30-3

Surtace

Deep water

Mean

28 4
i

20 9

20 4

31 9

Dead

i

Jt

i

1

These figures, however, appear abnormally high, for it must be remembered that
dead ova — at any rate those of cod and plaice — are only exceptionally found suspended
in the water, sinking otherwise very soon to the bottom, they would consequently only
appear in plankton samples by mere accident. Unfertilized cod eggs may remain
suspended for about two days; those of the plaice somewhat longer.

As to how far unfertilized or dead eggs appear in the samples from the Canadian
waters, I am unable to say on the basis of the preserved material; the question would
have to be dealt with by means of fresh plankton samples.

That cod eggs should be subject to " natural death " in any considerable degree
is hardly probable; if such were the case, the mortality figures at the hatchery would
be far higher than they are.

When working under normal conditions, solely with a view of obtaining the greatest
possible amount of living young, and without regard to what quantity may be lost,
the mortality i)ercentage at Flodevigen amounts annually to something like 12 per cent
for the entire period of hatching, including unfertilized eggs.

The figures for the three last years are as follows : —

Per cent.

1912 12-5

litis 13-S

1914 11-0

48 DEPARTMENT OF THE NAVAL SERVICE

These percentages are calculated from very large quantities, in 1913 for instance,
1,222 litres, about 550 millions of eggs, and they do not vary greatly from year to year.
When much brackish water occurs on the coast, the mortality may inci*ease considerably ;
this is, however, rarely of long duration. Similarly, if the weather for any length of
time is dark and cloudy, the eggs may become entirely overgrown with bacteria, from
which, however, they may be freed by being placed in a bath with water of high salinity.
As to the degree of influence exerted by these bacteria (Leptothrix?) in a natural
state I can say nothing from experience; possibly the conditions at the hatchery may
be especially favourable to them.

As regards the growing up of the young, we have here to consider another factor,
viz., that of nourishment. That this is of great importance to the growth of the
young is certain, and possibly the most critical period of all in this respect is the
time when the young first commence to take food; they do not live long without
nourishment after the yolk-sac has been consumed.

In the spring of 1914:, a number of newly hatched young were placed under
observation at Flodevigen for the purpose of ascertaining when they commenced to
take food, and what such then consisted of. The investigations were carried out by
Prof. H. H. Gran, and led to the result that the young did not take any food mitil
the yolk-sac had been absorbed, and that on commencing to feed, they appeared from
the first to prefer animal matter, such as mollusc larvse, nauplii, etc., seeming, strangely
enough, to despise the innumerable diatom forms which are likewise present in the
water.

Such food as was pumped in with the sea water was alone available to the young
fish; but as the greater part of the plankton was retained in the apparatus, the
nutritive matter was fairly concentrated there.

As to the influence exerted by conditions of nourishment upon the growing of the
young in a natural state, this question has not yet been investigated, and it will
probably form one of the earliest subjects for future fishery investigations.

It is, we may say, of prime importance in every way to ascertain what factor or
factors normally hinder the germs of our most important fish in their development,
to discover at what stage the destr\iction occurs, and by what means it takes place.

This will have to be done by investigation of the propagation of fish in the sea,
and by experiments and artificial culture, both branches of the work proceeding in
conjunction.

It is from such a point of view that I have in the foregoing pages endeavoured to
treat the material of fish eggs and young collected by the Canadian expedition. Unfor-
tunately, however, we still know far too little of these questions, and my work can
therefore only be regarded as furnishing, in this respect, a preliminary survey of the
complicated, yet highly interesting, conditions which prevail on the Atlantic coast
of Canada.

LITERATURE.
Alexander Agassiz.

1878. I. On the Young Stages of Bony Fishes.

1882. III. On the Young Stages of some Osseous Fishes.

Jordan and (xilbert.

1882. Synopsis Fishes of North America.

E. W. L. Holt.

1891. On the Eggs and Larvae of Teleosteans.

1893. On the Eggs and Larvae and Post-larval Stages of Teleosteans.

(The Scientific Transactions of the Royal Dublin Society, vols. IV
and V.)

CANADIAN FISHERIES EXPEDITION, lOUflS 49

W. Lilljeborg.

1891. Sveriges och Norgea Fiskar I-III.

Jordan and Evermann.

r396-1900. The Fishes of North and Middle America. Vols. I-IV.

C. G. Joh. Petersen.

1904. On the Larval and Post-larval Stages of the Long Rough Dab and the

Genus Pleuronecies.
(Meddelelser fra Kommissionen for Havundersogelser, Bd. 1, Xo. 1)

Johs. Schmidt.

1905. De Atlantiske torskearters pelagiske yngel i de post larvale stadier (Med-

delelser fra Kommissionen for Havundersogelser, Bd. 1, Xo. 4).

1906. The Pelagic Post-larval Stages of the Atlantic species of Gadus (Meddelel-

ser, Br. II No. 2).

E, Ehrenbaum.

1905-09. Eier und Larven von Fischen
(Nordisches Plankton).

A. Brauer.

1906. Die Tiefsee-Fische

(Valdivia Expedition Bd. XV).

Prof. Apstein.

• 1911. Die Verbreitung der pelagischen Fiseheier und Larven in der Beltsee und
den angrenzenden Meeresteilen 1908-09.

David Starr Jordan.

1914. A manual of the Vertebrate Animals of the Northern United States.

6551—4

CANADIAN FISHERIES EXrEDlTION, tOUrlS

Station 2—

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Station 13—

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Station 22—

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66 Hie 303 47

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Station S9-

Station 70-

->

207

-

"

'

'

'

31

m

2694

'

4479

'

7

6

337

'

4046

CANADIAN FISHERIES EXPEDITION, lOl-i-lo 57

Table II. — vSummary of the six most common species of fish. (All the cruises included.)

(xerminative
disk.

Surface.

Vertical hauls

.'

Pigmented
embryo .

Larvae.

(Jerminative
disk.

70

774

46

1773

208
3252

Pigmented
embryo.

74
392

45
520
116
300

Larvae.

245
2178
1118
10167
1323
4496

61
2231
1160
3528
1328
773

237
16
30

276
J9

81

Scomber

Drepanopsetta

31
17

Gadus

Onos

• 17
53

19527

9081

598

6123

14

199

* Here also included some de<^{) horizontal towings by ss. No. 33.

T.^BLE II a (1). — Egg and Larvse Ctenolahrus adspersus.

Date.

Germinative
disk.

Surface.

Pigmented
embryo.

Larvae.

Ve

Germinative
disk.

5

rtical hauls.

Pigmented
embryo.

Larvae.

"Acadia " I

May 29 to June 4..
•June 9 to June 15.
July 21 to July 2y.
Aug. 3 to Aug. 12.
June 1 to Aug. 18.

1
6

2
15

1

"Princess" I
Stati(»n 19-26

Acadia " II

21
18
26

37
11
26

1

'Princess" II
Station 27-50

"No. 33'
Station 5-48 .

4
234

33
11

237

79

245

61

237

70

74

81

(5551—8

58

DEPARTMENT OF TEE NAVAL SERVICE
Table II a (2). — Egg and larvae, Ctenolahrus adspersus.

—

Surface.

Vertical hauls.

"Acadia" I.
Station 5

Gernxinative
disk.

Pigmented
embryo.

Larvae.

Germinative
disk.

Pigmented
embryo.

Larvae.

1

2
3

1

II 6

1

II 8

1

1

2

5

1

"Princess" I.
Station 19

6

1

15

•1 26

6

15

"Acadia" II.
Station 91

21

37

1

"Princess "II.

Station 27 - . . .

28....

1, 29...

3

1

14
10

8

1

2""

33
23

17
1

8
3

53

5

•1 30 . . .

1

31

2

1. 48

75
54
50

II 49 .

50 ..

18

4

33

237

18

11

79

No. "33"—
Station 5

125

80

26

3

2
2
3

2

1

Vertical and deep horizontal.

II 6

II 7

II 8

11 10

II 35.

12
14

II 39 .

26

II 48

1

234

11

26

26

CA^'ADIA^Sl FI!?nERIES EXPEDITION, 19Vrl5
Table II a (3). — Larvae, Ctenolahrus adspersus.

59

Length in inm.

2

3

4
1

5

6

1

8

9

10

11

12

13

14

15

16

17

More th&n
17.

" Acadia" I

" Acadia "II
Station 91.

1

" Princess " II
Stat ion 28

55
38
24

,1 29

80 ....

31

1

1
75
54

68

.1 48

49

1. 50

Table lib (1). — Egg and Larvae, Scomber scomhrus.

Date.

Surface.

Vertical hauls.

Genninative
disk.

Pigmented
embryo.

Larvae.

Genninative
disk.

Pigmented
embryo.

Larvs.

"Acadia" I
Station 3-9..

May 29 to .June 4 .
June 9 to June 16.
Aug. 8 to Aug. 12.
June 1 to Aug. 18

3

263

80

1,832

2,178

" Princess " I
Station 24-26.

55

10

709

774

"Princess" II
Station 28-50.

"33"
Station 23-49.

204
2,027
2,231

16
16

14
378
392

31
31

6551—8^

^

DEPARTMENT OF THE NAVAL SERVICE
Table lib (2). — Egg and Larv«, Scomber scombrus.

Surface.

Vertical haul.

t' .

(rerrainative
disk.

Pigmented
embryo.

Larvfe.

Germinative
disk.

Pigmented
embryo.

Larvae.

" Acadia " I. —

Station 3

„ 9.

2

1 (?)

" Princess' I. —

Station 24

3

162

21
80

27

23

5

■ 11 25

„ ■ 26

263

2

1
75

55

'Princess" TI.—

Station 28

29

3"

171

30

1
1

,1 30

14

9
5

3

31

32

io

6
5

33

9

1. 34

1

„ 45

1

48

49

11 50

1

2

4

No. "33"-

'= Station 23

29

.1 35

HO

3
1.800

204

3
2,000

16

10

52:)

144

40

709

14

312
06

378

31

36

„ ■ 39

'4'
25

48

24

2,027

...; 49

.,. i

1,832

CANADIAX flf>HERlES E.XPEDITIOy, Wl'rlo

61

Table lib (3). — Lar\-£e, Scomber scomhrus.

Length in n.m.

2

3

4

5

6

1

7
....

8

9

10

11

12

13

14

15

16

17

More
than 17.

Princess II.—
Station 28

b
2
3
2

i'

3
5

29.. ..
30.. . .
31 ... .
32

3

t

1
1

1

1

« •

33

34 . ..

1

45

1

49

2

2

50...

2

Table lie (1). — Sehastes marinus.

Surface.

Vertical Hauk.

Date.

Larvae.

Larvte.

"Acadia " I—

Station 11-36

May 29 to June 4

56 (56)

19 (19)

" PrinceiS I —

Station 9 23

June 9 to June 15

6 ( 6)

102 93)

" Acadia" II —

Station 37-90

July 21 to July 29

73 (73)

155 (155)

" Princess " II —

Station 32-48

Aug. 3 to Aug. 12

50 (50)

170 (165)

No. "33"—

Station 19-58

June 1 to Aug. 18.

337 (37)

522 (222)

446 (43^

0 Numl^eis mea-sured.

62

DEPARTMENT OF THE NAVAL SERVICE

Table lie (2). — Sehastes marinus.

Surface.

Vertica

hauls.

Total number.

Midle length. 1

Total number.

Midle length.

" Acadia " I

Stat

ion 11

, 26

10

7-8

3

1
5
3
7

8.0

, 31

80

, 32

43

1
1
1

8-7
80

8-0
70

80

, 34

, 35

, 36

7-3
8 0

56

19

Stat

on 9

- 10

, 16

, 20

, 21

1
1

4

80
9 0

"" 7-8

34 (25)

7 ( 7)
.33 (33)
10 (10)
18 (18)

8-3

8.3
8 4
8 1

. ?>3

8 1

" Acadia " II —

Station 37

6

7
2

7 4
6 5

102 (93)

52
22
29

3

3

1

3
10
15

9

1

2
4
1

, 38

, 39

7-3
7-5

, 49

, 50

, 51

79

1
40

90

7-6

87

, 52

7.0

, 59

8 0

, 60

, 63

67

6-5

64

. 65

, 67

, 69

2

6-5
5-3
80

. 70

, 72

- 76

, 84

1
5
5

70
7-6

8-2

7.5

, 86»

10 5

- 88

, 90

?

73

6 3

8 0

80

155

Stat

on 32 .

1 ( 1)

21 (21)

14 (14)

8 ( 8)

1 ( 1)

11 ( 6)

4 ( 4)
36 (36)

1 ( 1)
24 (24)

2 [ 2)
40 (40)

5 ( 5)
2 ( 2)

90

, 34

9 6

.: 35 :: :::

11-7

„ 36

8.8

, 37

9 0

, 38

7 0

, 39

80

, 41

10 0

„ 42

100

, 43

10 3

, 44

8-5

, 45

38
8
3

1

8-9

&-6

13 3

80

87

. 46

, 47

7-8
120

. 48

50

• 170 (165)

^O. Ai —
Stat

ion 19

< 22

2 ( 2)
1 { 1)
5 ( 5)

325 (25)

3 ( 3)
1(1)

70
80

8 0
80

9 7
80

, 23

, 26

, 48

" ^'~'

337 (37)

CANADIAN FISHERIES EXPEDITION, 19U-15
Table II d. — Chirolophis sp.

63

Sur

'ace.

Vertical.

Total number.

Length in mm.

Total number.

Length in mm.

"Acadia I " -

Station 23

„ 34

1
5
2

10
ca. 10
ca. 10

„ 35

"Princess " I —

Station 11

8

16

3

1
2

ca. 12

8-10

10

ca. 8

2

,. 13

„ 18

- 24

„ 25

10-11

22

2

No. "33"-

6
1
3

2

ca. 12

12

11-13

ca. 8

18

1

„ 16

„ 17

„ 22

.. 39

8-10

„ 49

ca, 12

12

19

Table II e. — Liparis sp.

Surface.

Vertical hauls.

Total number.

Length in mm.

Total number.

Length in mm.

" Acadia " I —

Station 8

1

4

1

3

„ 24

1

1

" Princess " I —

1

5

1

„ 24

5

"Acadia" II —

Station 81

6
1

4-7

" Princess " II—

Station 36

10

1
1

9

„ 50

8

1
1

2

No. "33"—

Station 17

4

2

^ 1

„ 39

4-3

.. 57

25-30

■64 DEPARTMENT OF TEE NATAL SERVICE

Table II f (1). — Egg and Larvae, Drepanopsetta platessoides.

Date.

Surface,

Vertical hauls.

Germinative
disk.

Pigmented
embryo.

Larvae.

5

23

2

Germinative
disk.

10
29

7

Pigmented
embryo.

23

15
3

1
3

Larvae.

" Acadia " I

Station 8-36 .
"Princess ' I

Station 3-26,
" Acadia " II

Station 49-83
" Princess ■■ If

Station 30-50
"33"

Station 3-17.

May 29 to June 4..
June 6 to June 15
July 21 to July 29.
Aug. 3 to Aug. 12.
June 1 to \ug. 18.

322
260

7

529

734

3C5
25

96

7

5
5

1118

1160

30

46

45

17

Table II f (2). — Egg and Larvae, Drepanopsetta platessoides.

"Ac

St

-

Surface.

Vertical haul.

Gerniinative
disk.

Piginente.1
embryo.

Larvae.

Germinative
disk.

Pigmented
embryo.

Larvae.

adia" I

6

3

! 19

2

2

200

1
3
6

18
2
7

18

20..
21..
22..
23..
24..
25..
29..
30..
31 .
1 32

5
415

2
13
11
114
16
17

5
33
55
24
18

1
2

4

1

12

3

4

7

3

33..
34..

57
2
4

tl w. .

322

731

10

23

7

"Princess" I
Station 5..

3 "

1

7
2

1

2 ""

1
1

T

5 ""

1
2

': i^

3

10 .
11..

12..
15..
1 16

3

11

2

22

15
7
1

25

5

9

180

25

21
1
0

2

3

1 17

1
2
3
4

1
9

2 ""

6
1
1

, 18..
19..
24..
25

189

20

6

•>fi

1

*.v^ . .

200

305

g

26

15

CA^'ADIA^' FISHERIEfi EXPEDlTIOy, lOL'rJS
Table II f (2). — Egg and Larvae, Drepanopsetta platessoidcs — Con.

65

Surface.

Vertit-al haul.

Genninative

disk.

Pigmented

embryo.

Larva?.

Germinative
disk.

Pigmented
embryo.

Larvw.

Acadia" II
Station 49. .

1

81..

1
2
4

3

9

13

7

1
2

82..

3
1

83. .

16

7

25

23

3

-

" Princess" II
Station 36. .

1

37..

\

39

1
2
1

45..

50..

2

2

1

5

No. "33"
Station 3. .

6

3

4..

2
2
9

7
2
9

1

1

10

8
1

5..

■

6..

7..

8..

9..

1
2
1

10..

1

11..

12 .

13..

1

40 ""

35

7

14..

8

310

95

73

15..

16..

17..

529

96

(

3

66 DEPARTMENT OF THE NAVAL SERVICE

Table II f (3). — ^Larvae, Drepanopsetta platessoides.

Length in mm.

2

3

4

5

2

6

2
1

7
....

8

9

10

11

12

13

14

15

16

17

More than
17.

"Acadia" I —
Station 8

„ 25

"Acadia" II —
Station 49

1

i

81

6

82

3

"7"

83

1

1

"Princess" I —

Station 8

6

"Princess" II —
Station 37

39

1

45

2(20 mm.)

60

2

1

Table II g (1). — Egg and Larvae, Gadus sp.

Date.

Surface.

Vertical hauls.

Egg.

Larvae.

Egg.

Lar

vie.

S .

s.-l

C5

6

1

1
§

.a

a

s
'"5

t

1

5s

>

a ■
■"-«

0

d

tu
S
bo

.a

1
a

1
1

a

s

!

a

05

"Acadia" I —

Station 5-3G..

May 29 to June 4...

1601

2025

59

31

1

116

158

5

47

3

1

"Princess" I —

Station 3-26. .

June 9 to -Tune 15. . .

3940

743

9

6

375

56

3

1

" Acadia" II —

Station 49-84..
" Princess" II —

Jiily 21 to July 29...

284

187

43

28

250

14

23

10

1

10

1

Station 27-50. .
";-13"—

Aug. 3 to Aug. 12...

310

152

19

4

1081

188

14

2

Station 4-58..

June 1 to Aug. 18. . .

4032

232

1

178

31

6

10167

3339

130

59

262

14

1773

413

2K

49

15

2

CAXADIAX FI.'^HERIES EXPEDITION, 191/rl5

67

Table Jiff (2). — Egg and Larvae, Gadus sp.

i

Surface.

Vertical hauli*.

Egg- 1

Larvae.

Kgg- j

Larvae.

"

s'-S

'at

T3 d

It

i

1
1

6

C3

.2

0

-J

0

s >

u •—
1) -^

0

is

6

i

0

6

is

0

"Acadia" I.—

Station 5

6

7

8

61
94

146

1

55

47

850
70
60
4
20
86
60
19

4

1,250

137

1

"15

ca. 10(

11

' i

)dama

ged eg|

12

66

's, prol

23

1

1

40
6

2

1

••ii7:;:;i

)ably haddock

24 1 3
1

1

1

1. 9

„ 19

76

32

440

1

1

13
42

5

1

19
2

2

""44

1

3
2

„ 20

„ 21

„ 22

.. 23

„ 24

II 25

6

6

1

,. 29

30

7

T
1

116

12
2

1

2

. 31

„ 32

„ 33

32
20
26

„ 34

n 36

".Princess" I. —
No. 33.—
Station 4

1,601

2,025

59

31

1

158

5

47

3

1

60

4

1,700

600

150

100

153

150

30

7

83

500

115

124

73

21

33

3

1

1
2
4

20

35
6

17
5

27

60

1

9

108

2

3
13
13

5

1

5

6

7

8

9

10

„ 11

„ 12

„ 13

„ 14

„ 15

1, 16

.. 17

„ 19

M 21

,- 22

„ 26

36

„ 39

„ 48

2
116

96

1

n 49

57

„ 58

n

15

4,032

4

232

1

178

31

6

"Acadia" II. —

Station 49

11 59

5

3

1

61

62

63

66

M 68

90

105

1

20
14

1
2

1

6
1
1
2

"ii

9
3

1

1

3

5

1

10

80

81

82

II 83

6
37
40

1

13

65

71

4

3
11
13

8

' 11

17

12
20

3
206

9

84

1 284

187

43

28

250

14

2.T

10

1

in

1

68

DEPARTMENT OF THE' NAVAL SERVICE

Table II g (2). — Egg and Larvae, Gadus sp. — Con.

'Princess " II.
Station 30.
31.
32.
36
37.
40.
42.
45.
48
49.
50.

" Princess " I.
Station 5.

6.

7.

8.

9.
10,
11.
12.
15.
16.
17.
18.
19.
20.
22.
24.
25.
26.

Surface.

Egg.

1

148

48
113

310

45

152

206

618

69

" 49

29

9

5

34

l,07v

855

750

51
37

15^

3,940

26

82

10

1

44

3

1

18

15

54

307

135

9
21
17

743

19

C5

Larvae.

Vertical hauls.

Egg.

c-c

24

124

687

8'

41

104

2

1,081

c 0^

188

14

Larvae.

1

1

22

2

48

7

19

2

1

3

2

1

8

5

2

4

5

1

1

1

9

114

12

1

29

5

47

3

1

4

5

30

3

3!'

4

375

56

3

1

"Acadia" 7 —

Station 3-29..
"Princes.s " I--

Station (U17..
"Acadia" II —

Station 47-62
"Princess "II —

Station 27-50
" 33 "

Station 19-39

CANADFAN FIf?HERIEH EXf'EDlTlON, 1911,-15
Table lie: (3). — Larva?, Gadus callarias.

69

Le

ngth in mm.

2

3

1

4

5

6

7

8

9

10

11

12

13

14

15

15

17

More than
17.

" Acadia " I —
Station 6 . . . .

„ 8

1
1

2
2

3

1

25

" Princess " I—
Station 8

M 20 ... .

4
20

1

1
1

1

" Acadia " II—
Station 80

4

81

82 ... .
83 ... .

2

2i6'

n 84

'9

1

2

" Princess" II —

1

1

1

"33"
Station 57

1(21 mm)

1

Tabiii: II g (4). — Larvae, G. aeglefinus.

Length

in mm.

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

More than
17.

"Acadia " I—
Station fi

1

Acadia" II —

i

1

2

59

1

68

.. 81

3
1
1

3

82

83

S4

2

I'abi.k nil (1). — Egg and Larvi^, Onos.

Surface.

V

ertical hau

s.

Date.

Germ-
inative
disk.

Pigmen-
ted
embryo.

Larv«.

Germ-

inative

di.sk.

Pigmen-
ted
embryo.

Larvae.

Ma^ 29 to .Tune 4..
June 9 to June 15
July 21 to July 29.
.Aug. 3 to Aug. 12.
June 1 to Aug. 18.

5

1.")

15S

23

1122

1

2

35

21

1269

1

11

2

194

2

5
109

1

35
4

52

1323

1328

39

208

IKi

53

70

DEPARTMENT OF THE NATAL SERTICE
Table II h (2). — Egg and Larvse, Onos.

Surface,

Vertical hauls

Gerrainative
disk.

1
3

Pigmented
embryo.

Larvae.

Gerniinative
disk.

Pigmented
embryo .

Larvae.

" Acadi
Sta

a" I-

.ion 3

5

6

1

19

29

1

1
1

5

1

" Princ

Sta

888 " I —

bion fi

8

9

10

10
4

1

1

1

1

1

16

, 18

2

i5

1

2

" Acadi
Sta

a " II-

tion 47

, 49

20
10

20

10

1

56

61

120

8

15

62

158

35

11

" Princ

Sta

BSS" II —

tion 27

4

15

4

4

8
7
2

1
1

2

2

28

35

29

30

25

5

8

1

31

3

32 .

1

39

1

49

1
4

1

, 50

3

23

21

35

2

5

52

No. "2
Sta

3"—

tion 19

21

22

800

3

9

220

15

75

1000

3

31

200

10

25

110
84

108
1

23

25

26 . .

29

4

35

39

1122

1269

4

194

109

CATfADIAN FISHERIES EXPEDITION, 19U-15
Table II h (3). — Larvae, Onos.

71

Length in mm.

2

3

1

3
3
6

i'

4

5

6

7

8

9

10

11

12

13

14

15

16

17

More
than 17.

"Acadia" I —
Station 6

"Piincess" II—
Station 28

5
3

29

30

31

3
1

1

7

4

32

49

50

No. "33"—
Station 29

Table II i. — Egg and Larvae, Merluccius merluccius.

Surface.

Vertical haul

Germinative
disk.

Pigmented
embryo.

Larvfe.

Germinative
disk.

Pigmented
embryo.

LarviB.

' Acadia " II —
Station 44

2

7

2650

176

1

"266"'

750

400

300

10

1^
1400

1

50

1800

100
200

47

53

350

12

1

5

250

85

70

54

55

56

58

59

60

61

62

4496

773

3252

300

72

DEPARTMENT OF THE N iVAL FiERVIC^
Table ITj. — Ammodytes tohianus.

Surface.

Vertical hauls.

Total number.

Length in nun.

Total number.

Length in mm.

" Acadia" I—

2

5
1
7

9
3

8
1
2

6
1

4

ca 15

„ 5

1

ca 25

ca 15

M 8 . .

15-22

19

21

5
4
2

15-20
ca 1!")
12-15

- 22

23

6-10

24

25

26

31

17
3

10-18

io-15"""

8-14

10-13

10

12-20

32

7

8-22

.1 34

ca 15

36

5

12-17

12

46

43

"Princess " I —
Station 9

1
2

1

15

7-7
18

15

16

4

" Acadia " II —
Station 82

1
3

15
12-20

1

16

„ 83

4

1

No. " 33 "—

2
4
2

10-20
ca 8
12-13

— —

M 17

21

8

CA\.\nr\\' /7N///; /.'//•>• E\f'i:niTio\, wj',-i5

73

Tari.k Ilk. —^fallofllf! villosns.

Surface.

Vertical liauls.

Total number.

1
12

ca 75

Lenprth in mm.

1
Total number. '

Length in niiii.

"Acadia" I—

Station 30 '. . . .

"Princess" I —

Station 4

"Acadia" II —

Station P3

"Princess" II —

Station 34

1
42

10-15
7-25

1

1

15

1

1

ca 325

15
12
22

M 41

„ 42

16

12

,■ 45

7-25

ca 75

ca 342

No. "33"-

Station 17

3
3

ca 8

» 58 ..

6

Table II 1. — Scopelus sp.

'Acadia" I —

Station 16
.. 17
'Acadia" II —

Station 3^i
„ 42
.. 44
., 45
M 46

M 51

.. 74
M 75

37
4
2
1
1
5
1

56

8-11

C-9

14-16

5-6

8

6

6-12

9

13
3

6
33

7-14
6-10

7
8

6-16
S-21

6551—9

74

DEPARTMENT OF THE 2s'A7AL SERVICE

EXPLANATION OF PLATES

Plate I.

Fig.

Ctenoluhrus adspersus, 4'2 mm., Princess Station, 50 (surface).

Ctenolabrus adspersuSj 8 mm., Princess Station, 50 (surface).

Scomber scombrus, 6"2 mm.. Princess Station, 33 (obi. haul).

Sebastes marimis, 5'6 mm., Kristianiafjorden July 1913 (taken from the adult fish).

a and b, Sebastes murinus 8 mm., No. " 33 " Station, 26.

a and b. Sebastes viarinus, 10*4 mm., Princess Station, 46 (surface).

Sebastes niai'inns, 20 mm., PiHncess Station 41 (30-0).

Plate II.

Fig. 8. Chirolophis ?, 11mm., Princess Station 13 (100-0).

9. Stichatts punctatus, 30 mm., Acadia Station, 89 (surface).

" 10. Cryptacanthodes nChculatus, 38 mm.. Princess Station, 8 (80-0)

" 11. Pleuroncctes cynoglossus, 16 mm., details lost.

" 12. Ancylopsetta sp., 7 mm., Acadia Station, 44 (surface).

" 13. Drepanopsetta platessoides, Acadia Station, 25 (120-0).

" 14. Drepanopsetta platessoides, 7 mm., Acadia Station, 82 (30-0 fms).

" 15. Drepanopsetta platessoides, 13 mm., Acadia Station, 81 (surface).

Plate III.

Fig. 16. Gadus callarias, 3*8 mm.. The Flodevig- Sea Fish Hatchery.

" 17. Gadus callarias, 4'5 mm., Acadia Station, 8 (vertical).

" IS. Gadus callarias, 11 mm.. Princess Station, 20 (surface).

" 19. Gadus aeglefinus, 3"7 mm., Acadia Station, 81 (surface).

" 20. Gadus aeglefijius, 7 mm., Acadia Station, 59 (25-0 fms.)

" 21. Onos cimbrius (?), 4*4 m.. Princess Station, 50 (40-0).

" 22. Onos cimbrius (?), 4*6 mm., Princess Station, 31 (oblique).

" 23. Ammodytes tobianus, 7*2 mm., Acadia Station, 23 (70-0).

" 24. Ammodytes tobianus, ca., 15 m., Acadia Station, 82 (30-0 fms.)

" 25. Tetragonurus cuvieri, 76 mm., Acadia Station, 56 (210-140 fms.)

" 26. Mallotus villosus, 8 mm.. Princess Station, 45 (oblique).

" 27. Mallotus villosus, 19 mm., Princess Station, 45 (130-0).

The figures, except those of macroscopical fishes, are drawn from specimens
imbedded in glycerine-gelatine, transferred 'directly from formaline 4 per cent with-
out being cleared or stained. The originals of figs. 3, 4, and 10, however, are borax-
stained specimens mounted in Canada balsam.

All drawings from original material by Mr. Thorolv Rasmussen, draughtsman to
the Fishery Board of Norway.

All depths in meters, when not otherwise stated.

PLATE I.

CANADIAN FISH EGGS AND LARV^. DANNEVIG.

^.

'-^.

5.6 m.fn.

5a

•

#

6b

>-

da

^^

^

5?

10.*t tM.m

2o fTi.fn

PLATE II.

CANADIAN FISH EGGS AND LARV^. DANNEVIG.

.././.

■ t:

.y~^- '. '"7 'X'

Xf ■ • •■■ ., ' .^ . . ,, ■ . ,

15

^

;::^

I3m."i-

PLATE III.

38 m

CANADIAN FISH EGGS AND LARV^. DANNEVIG.
16 19

3 7 Ml

18

26

^

CANADIAN FISHERIES' EXPEDITION, 1914-15

BIOLOGY OF ATLANTIC WATERS OF CAiNADA

REPORT ON "AGE AND GROWTH OF THE
HERRING IN CANADIAN WATERS"

BY

EINAR LEA,

Bergen, Norway

6551—9.1

AGE \XD GROWTH OF HERRING IN CANADIAN WATERS
BY EINAR LEA, BERGEN, NORWAY.

CONTENTS.

Page.

"A " (Jknkual.

81
I Introduction

II Methods of determining age and growth in herring 81

III Structure of herring scales

IV Scales as an indication of age. Sources of error 9:3

V The scales as an indication of growth. Sources of error 100

VI Age determination and growth measurement in practice 101

VII Preparation of scales for preservation 101

VIII Definitions and abbreviations lO"!

IX Collecting of material

"B" Spkcial.

The Canadian Material.

X Description and preliminary grouping of material 115

XI Age (a) Waters about Prince Edward Island 116

(&) Waters about Magdalen Islands 1^1

(c) Newfoundland waters 122

(d) Cape North southwards along Atlantic Coast 126

(e) Comparison of the different areas 130

XII Growth.

Comparison of growth in samples of similar age composition . . . . 132

1. Samples from Newfoundland 132

2. " " Magdalen Islands 13"

3. " " Northumberland Straits 139

4. " " North Sydney compared with exceptional

sample from St. George's Bay, Nfd.. . 143

5. Samples differing in age composition 146

6. Comparison with Magdalen Islands samples 147

7. Comparison with exceptional sample from St. George's Bay. 148

8. Comparison with sample from North Sydney 149

9. Comparison with old fish from West Ardoise, etc 150

10. Graphical illustrations of results obtained 150

11. Samples from Magdalen Islands compared with remainder. 153

12. Graphical illustration of the results obtained 155

13. Samples from Northumberland Straits, North Sydney, and

the Atlantic coast compared 156

14. Summary 1"^ '

XII Appendix. Observations as to seasonal growtJi in young herring. . . . 157

XIV Results of age and growth studies viewed in the light of observations

as to the racial characters 1"*9

77

LIST OF PLATES AND TEXT FIGURES.

Plate I.

Fig. 1. Herring' scale on a dark background: the winter rings appear darker than
the summer zones. xl4. (Lea phot.)

Plate IT.

Fig. 2. Herring scale on light background: the winter rings appear brighter than the
the summer zones. xl4. (Lea phot.)

Plate HI.

Fig. 3. Left half: Impression in a collodion film of surface of portion of a herring
scale. Right half: Same portion of the actual scale itself. xl5.

Fig. 4. Scale split, the detached part showing a contour similar to that of the whole
scale; pattern formed by fibrils on the surface of distension. x9.

(Lea phot.)

Plate IV.

Fig. 6. Part of herring scale, the outer covering removed, showing margins of
fibrillar plates with alternating tangential and radial course of the
fibrils. x75. (Lea phot.)

Fig. S. Part of cross-section through a herring scale, stained with thionine. x380.

(Lea phot.)

Fig. 13. Effect of silver impregnation acting from the outer surface of a scale. xl70.

(Lea phot.)
Plvi'eV.

Fig. 14. Total views of a herring scale, impregnated with silver, demonstrating the
inner system of annual zones. Oblique illumination. xl3.

Fig. 15. Half of a scale with normal structure. xl7.

Fig. 16. Half of a scale with abnormal structure from the same herring as the scale
shown in Fig. 15. xl7. (Lea phot.)

Plate VL

Fig. 17. Part of an abnormal scale, the outer covering layer of which is removed,
showing irregular course of fibrils. xl()7. Compare with fig. 6, Plate IV.

!Pig. 18. a. b. c, d. The appearance of scales situated near an abnormal one. Central
portion of four scales shown, taken in successive order from a lateral
scale-row :

a. Ninth scale in the row being normal,

h. Tenth scale in the row being slightly modified,

c. Eleventh scale, being greatly modified,

d. Twelfth scale is abnormal. The next scales in the row (on the other side

of the abnormal one) show similar feature^.

Fig. 23. Pa't of a scale, showing faint concentric shadows, caused by the inner
fibiilbar plates (corresponding to Fig. 14, Plate V). x9. (Lea phol.)

78

CAXADfAX FisnEinr:s; expeditiow loi.'i-irj 79

Pr.ATR VII.

Fig. 19. Herring scale from iiortliernmost Xorway, end of April, showing the com-
meneenient of a new .summer's growth. xlO. (Lka phot.)

Fi(;uui:s IN THE ti;\t:

Fig. 5. a. and o. Showing pattern formed hy fil)rils in the inner surface of small
(young) herring's scale,
c. Pattern a superposed over pattern h. Diagrammatic.

Fig. 7. Herring scale in section. Highl.y diagrammatic.

Fig. !). Edge of a herring scale in section, indicating true proportions.

Fig. 10. More central portion of a herring scale in section, showing the appearance
of a radial furrow : true pro]X)rtions.

Fig. 11. Part of a section of a herring scale, the position of two winter rings indicated.
True proportions.

Fig. 12. Effect of silver impregnation of the inner surface of a scale, the course of
the fibrils being indicated by small dark spindle-shaped particles. Dia-
grammatic.

Fig. 20. Showing average increase of the last (new) summer belt during the sunnner
of 1910 on the scales of young fish caught near Bergen.

Fig. 21. Composition in point of age of the stock of Norwegian mature herring, during
a series of years as shown by the samples investigated. (From Hjort.)

Fig. 22. a. Shows a scale with normal arrangement of winter rings,

h. Shows a scale with abnormal arrangement of winter rings, the distance
between second and third rings being small.

Fig. 24. Marking off the growth of scale on a paper sliii.

Fig. 25. Multiplying the distances marked off on the paper slips by help of a triangle
with a moveable side.

Fig. 26. Composition in point of age of all the seine samples of mature Norwegian
herringi, spring of 191 (i.

Fig. 27. Frequency cui"A'es for growth-dimension /, in Norwegian herring of the year
group 1904, during a series of years.

Fig. 28. Chart showing localities mentioned in the following: the black numbered
dots show the positions of the stations of " Steam Drifter No. 33,"
during summer 1915.

Fig. 29. Age composition of five samples from various places in Northumberland
Strait, spring of 1914 and 1915, each sample kept .separate: the indivi-
duals arranged according to age.

Fig. 30. Composition in point of year-groups of five samples from various places in
Northumberland Strait, spring of 1914 and 1915; samples from each
season taken together.

Fig. 31. Age-composition in two samples from iNfagdalen Islands, spring of 1914 and
1915.

Fig. 33. Age composition in samples from the coast of Newfoundland, spring 191:1

,80 DEPARTMENT OF THE NATAL SERVICE

Fig. 33. Age composition in samples from the coast of Newfoundland, autumn 1914.

Fig. H-i. Age composition in samples from the coast of Xewfoundland, spring 1915.

Fig. 35. Composition in point of year-groups in samples from the coast of Newfound-
land, samples from each season taken together. Spring 1914, autumn
1914, spring 1915.

Fig. 36. Age composition in North Sydney sample, June 3i, 1915, compared with that
of a divergent sample, St. George's Bay, May 27, 1915.

Fig. 37. Age composition in two samples from West Ardoise (July and August 1914)
taken together, compared with that of a sample from west of Port Hood
(station 42), July, 1915.

Fig. 38. Age composition in samples from different waters, 1914 and 1915.

Fig. 40. Growth of Newfoundland herring compared with that of herring from Mag-
dalen islands and Northumberland Strait, Curves in upper part for
increments (t), curves in lower part for lengths )(1).

Fig. 41. Growth of Newfoundland herring compared with that of herring from North
Sydney and Atlantic coast. 1

Fig. 42. Growth of Magdalen islands herring compared with that of herring from
North Sydney and Atlantic coast. i

Fig. 43. Graph indicating the course of seasonal growth in the West Bay of Port au
Port.

Fig. 44. Graph indicating the course of seasonal growth in the waters between the
coast of Gaspe and Prince Edward Island.

I'ig. 45. Graph indicating the course of seasonal growth in the waters from Souris,
P. E. I., southwards.

REPORT ON ''AGE AND GROWTH OF THE HERRING IN CANADIAN WATERS."

I.— INTRODUCTION.

Dr. Johau Hjort has requested me to ^work up the material of scale samples and
observations bearing on the biology of the herring, collected in Canadian waters
during the Dominion Government expedition, 1914 and 1915. The points especially
taken into consideration ,'when collecting the material — and which naturally also
furnish the main problems to be dealt with in the present work — have been formulated
by Dr. Hjort, in his preliminary report (VI) as follows: —

1. Do the herring that visit the Atlantic coast of Canada all belong to a
single race or^type, or is it possible to distinguish several races in these waters?

2. Does the rate of growth vary (according to the conditions of the waters
along the coast) ? Can types of different growth be distinguished and defined ?

3. Is the renewal of the stock of herring of a constant character, or are
there the same great fluctuations in the stock (in the number of individuals
belonging to the different year-classes) as in European waters?

A small portion of the material collected consists of biometrical observations.,
i. e., determinations of number of vertebrae, number of fin rays, and number of keel
scales, these being characters which, as Heincke has shown, may serve as a basis for
morphological distinctions between different tribes or races of herring. The greater
part of the material consists of observations as to length, weight, sex, state of sexual
organs, and fat, accompanied by scale samples serving for determinations as to age
and growth.

The material embraces a considerable geographical area, including, as it does,
samples from southern waters of Canada (including a series from Gloucester, Mass.,
U.S.A.), Bay of Fundy, Nova Scotia, Cape Breton island, Newfoundland, Magdalen
islands, Northumberland strait and as far north as the Gaspe waters. In some of these
localities, moreover, the collection of material extended over several seasons, and there
are also various samples taken with different fishing implements.

The results arrived at on examination of this material will be describetl in the
following pages. From the nature of the material itself, the greatest weight will
necessarily be attached to the discussion of that portion which deals with the age and
growth of the fish, as indicated by the state of the scales. A brief preliminary des-
cription and explanation will therefore be given as to the methods employed in scale
investigations, with observations as to the practicability of the method for dealing
with the herring in transatlantic waters.

II.— METHODS OF AGE DETERMINATION AND GROWTH MEASURE-
MENT IN HERRING.

It was early discovered that t3ie bony parts of fish were built up in layers,
resembling the annual rings visible in the trunk of a tree, and as far back as the
eighteenth century, the suggestion was advanced that it might prove possible, by

SI

82 DEPARTMENT OF THE NATAL SERVICE

counting these layers, to arrive at the age of the specimen. This theory was formu-
lated in 1759 by a Swede, Pastor Hederstrom, in the following manner : " Anyone
taking the trouble to examine a vertebra from a boiled fish, will observe certain rings
thereon. And as many rings as there may be, so many years will be the age of the
fish."

This suggestion, however, was afterwards lost sight of, and it was not until about
1900 that the skeletal parts of fish were called into requisition for the purpose of age
determinations. The same observation was then revived by two scientists, Hoffbauer
(VIII) and Reibisch (XIII) and the question has since been further dealt with by
many others.^.

It has been found that the different bony parts are not all equally well suited for
the purpose of age determinations ; in the case of the plaice, for instance, the scales
are difiicult to deal with from this point of view, being small, and with indistinct ring
formation. In this species, the otoliths and the opercular bones furnish the best
means of ascertaining the age. In the case of the herring, the opposite has been found
to be the case, the otoliths are here small, and awkward in shape, whereas the scales
are large, easily collected, and distinctly ringed. Although the otoliths and vertebra?
of the herring can be, and have been, used for age determination, the scales offer so
many advantages that there can, in my opinion, be no question as to choice. In the
following pages, the structure of these scales will be briefly described, with special
reference to the pattern of the annual rings. A resume will likewise be given of the
exact facts adducible in proof that the ring formation actually does consist of annual
rings, and that the scales may therefore be employed for the purpose of age deter-
mination. Finally, mention will be made of the methods of preparation and investiga-
tion which the writer's experience has shown to be most convenient.

III.— STRUCTURE OF HERRING SCALES.

On examining a number of herring scales, it will be found that these are thin,
pliable plates, differing both in size and shape according to the position on the body
of the fish. The scales from the forepart of the body are larger than those from the
caudal region, and those on the back smaller than those situate farther down, near
the lateral line, etc. The shape, or outer contour, differs between scales set, for
instance, immediately behind the gill cover and those farther back. Most scales are,
however, more or less, of the shape, shown in fig. 1, which is reproduced from a photo-
graph of a scale taken from near the lateral line, almost straight above the pectoral
fin. A feature common to almost all scales is the fact that the anterior portion, which
lies embedded in the scale pocket, presents an entirely different appearance to that
of the posterior portion. The former is of even contour, and appears to be finely
striped{, whereas the latter has a fringed contour, and lacks the fine striped pattern.
The two portions are divided by a line, termed the basal line (h — h in plate I, fig. 1).
The stripes of the anterior portion appear to fall into two distinct systems, with a
zigzag boundary between, this being as a rule ahr.ost perpendicular to the basal line
(z — c in plate I, fig. 1). At the point of intersection between this zigzag line and the
tasal line lies the centre of the scale (c) ; this is in most cases distinctly marked, but
may scarcely be seen on this figure. In addition to the fine stripes, a number of very
pronounced lines are seen running from the margin some distance in (r) ; these are
called the radial lines, from the fact that in the scales of many species of fish, the
corresponding lines radiate out from the centre of the scale. In plate I, fig. 1 will
be seen eight dark narrow lines, arranged concentrically about the middle of the

lA list of the most important works on tliis subject will be found in Dahl (I) The assess-
ment of ane ajid growth in fish, Intern. Revue d. gesamt. Hydrobiologie u. Hydrographie 1909.
Bd. 11.

CAXADr.W Flf^flEJilEH EXPEDITIOX, 191 ',-1}

83

scale; these divide tlie striped iiortiou of the scale into nine zones, each havin/r the
outline of a horseshoe; in plate I, fij;. 1 these appear lighter than the narrow lines.
By altering the light in which they are viewed, these broad zones can be made to
appear darker than the narrow lines (plate 11, fig. 2). These latter are the winter
rings of the scale, and the broader zones representing summer growth; it is by count-

Plate I.

ing these that the age of the tish is determined, and by measuring the distance between
them, it is possible to calculate the growth.

It is an easy matter to show that all the details above referred to pertain to the
outer surface of the scale, i. e., that surface of the scale which faces outward when
the scale itself is in its normal position on the body. The optical effect is a result
of reflection and refraction in this external surface. The demonstration may most
easily be made by producing an impression of the outer surface of the scale in a

84 DEPARTMENT OF THE l^ATAL SERVICE

transparent plastic mass, as, for instance, collodium solution. The scale is glued to
a glass plate, with its inner sidd next the glass, a small quantity of collodium is
poured over the whole, and the glass set aside in a slanting position, to dry. After a
short time, when still soft, the collodium may be removed in the shape of a thin film,
in which will be found an impress of the surface of the scale. Plate III, fig. 3, shows

Plate II.

,.'/?;u'^W'7^f^^n'^f-u

'<■■ /

FIG, 2

a photographic reproduction of a part of such an impression, together with the corres-
ponding part of a photograph of the scale itself. All details are distinctly visible in
the plastic impression. From this experiment we may with perfect certainty conclude
that the picture presented to the eye when observing a herring scale through a low-
power lens, is nothing but the play of light on the surface of the scale, which is thus
found to be moulded in delicate and detailed relief. The visible winter rings and
summer zones, like the fine stripes, the basal line, and the centrepoint, all belong
solely to the surface of the scale.

CAXADIAX FlHllElilES FXPEDITIOX. 191 ',-15

85

The inner structure of the scale tlius plays no part in the formation of the pic-
ture presented by the visible system of annual rings. It is possible, however, by par-

Plate III.

IG. 3

ticular means, to bring out another system of annual rings, located in close relation
to those of the outer surface, yet altogether different from these. In order to com-
prehend the genesis of this inner system, it will be necessary to have some idea as to
the internal structure of the scale as a whole. This may be arrived at by various

86

DEPARTMENT OF THE NATAL SERVICE

simple methods, the results of which will be found to agree with those obtained by
more complicated experimental processes.

With the aid of a needle and tweezers, a herring scale may be split up into
several thin plates, all exhibiting a contour identical in form with that of the scale
itself. The scale can only be thus split by inserting the point of the needle in the
outer surface, and the size of the flakes thrown off will depend upon whether the cleav-
age is commenced near the edge of the scale or farther in towards the centre. By
commencing near the margin, two large plates will be obtained, starting from a point
farther it will give one large and one small. Plate III, fig. 4 shows the two portions
of a scale thus split. The central portion here thrown otf presents the appearance of
a small scale, with the margin somewhat torn, the remainder, constituting the larger
part, exhibits a transparent " sore " in its central portion corresponding to the smaller
flake detached. From such experiments it may be seen that the scale is built up of
thin plates, similarly formed, each somewhat smaller than the next. The layers must
have been deposited in order of size, forming something approaching a very low cone,
the base of which is represented by the inner surface of the scale, and the apex by the
centre. The exact number of layers of which a sca^e is composed cannot be deter-
mined by mechanical means, as it is impossible to say whether each flake detached
comprises but a single layer, or is itself composed of several adhering together.

In a scale thus split, the surface exposed reveals a kind of pattern formed by fine
fibrils curving in prcs and whorls (vide plate III, fig. 4.) In most cases it will be
found that the fibrils nearest the edge of the exposed portion run parallel
with the same, while those farther in, on the anterior part, form a kind of elUptical
figure, and those in rear, on the posterior part (viewing the scale as in its normal
position on the body) form irregular whorls. From the pictures thus presented,
which are almost always to be found in such exposed portions where flakes have been
detached, it might well seem that the fibrils in each elementary plate were arranged
in this manner, with tangential marginal fibrils. This is, however, not the case, for
on studying the arrangement of the fibrils in scale preparations obtained by other
methods one may sometimes find the pattern above described, and in other cases pat-
terns of altogether different character.

The inner side of the scale is formed by a fibrillar plate, and, with a fairly
strong lens, the fibrils in this may easily be seen, especially if the scales are first

a

Fig. 5.

treated with nitric acid, and, in mounting, placed with the outer side down in a drop
of glycerine, leaving the inner side upwards, exposed to the air. On examining a
number of such preparations, not a few will be found in which the fibrils, instead of
running tangentially to the edge of the scale, fall perpendicularly to this, at any rate

CANADIAN FISUERIES EXPEDITION, lOl'rlo

87

along the greater part of the margin. In the case of hirge scales, the fibrils form a
highly complicated pattern farther in towards the centre. With small scales thus pre-
pared the patterns formed by the fibrils may be divided into two types, schematically
shown in fig. 5. a and h. The one of these types is characterized by a more or less
elliptical figure, and by the fact that the marginal fibrils run tangentially, the other by
a hyperbolar figure and radial marginal fibrils. There is thus no doubt that in addition
to elementary plates with tangential marginal fibrils, there must also be others with
radial fibrils, and the fact that these latter are rarely if ever found in the exposed sur-
face of a split scale must be due to the method employed. It is also obvious, that a
needle, thrust in with the point directed towards the centre, will find no hold until in-
comes'into contact with transverse fibrils, i. e. until it reaches a plate with tangential

fibrils. ^ £ iix n

The scale may thus be considered as a greatly flattened cone composed ol tihnll-
ary plates, of which some have tangential fibrils, others radial. This cone is evidently
covered entirely by a non-fibrillary layer, on the upper side of which, however, is
found finely marked relief which gives the scales its characteristic appearance. If
this covering layer could be removed, the margin of each fibrillary plate would then
be visible, since'^each plate is larger than the next. A method by which large portions
at least of the covering layer can be removed is as follows : A drop of fish glue is
placed upon an object glass, and a scale set thereon, with the outer side downwards
in the glue, leaving, however, a small corner of the scale free, just large enough to
afl'ord a hold for the tweezers. As soon as the glue has dried the scale is damped very
slightly with an almost dry brush, the free corner is then grasped with the tweezers,
and the scale torn away. If the operator is fortunate, the covering layer of the scale
will then be found adhering to the glue on the glass, and the part detached by the
tweezers may be mounted for observation. Plate IV, fig. 6 gives a photographic repro-
duction of part of such a preparation. The curved boundary lines of the elementary
plates are distinctly visible, and it will also be seen that plates with tangential fibrils
alternate with those having the fibrils radially arranged.

It will be easily understood that the arrangement of the fibrils in the elementary
plates as here described imparts to the scale a high degree of firmness in all direc-
tions, the fibrils in one lamella will, roughly speaking, form a considerable angle with
those of the two adjacent, so that the scale may, in a way, be compared with the com-
posite wooden plates which are made by gluing several thin sheets together, with the
grain of each perpendicular to that of the two adjacent. Fig. 5 c gives, purely schem-
atically, the arrangement of the fibrils in two plates, one with radial, the other with
tangential fibrils, showing the manner in which the direction of the fibrils in the one
lies transversely to that of those in the other, when two such plates are placed in
juxtaposition.

Fig.

Judging from what we have hitherto learned, the transverse section of a scale
should pl-eseut more or less the appearance shown in fig. 7. This is also, roughly
speaking, found to be case. The upper covering layer can be distinctly seen when the
section is stained with thionine, as shown in fig. 8, the layer in question then assuming

Plate IV.

!T7"?'rjggg"

?1G.8

-^t^A^^

FIG. 13

C.\\.\rn\\ FISflFRfF.^ F.Xrr.DITloy, 101 'r15

89

an intense blue colour, while all the remainder is unaffected.^ Sections show that
this upper covering layer is of almost equal thickness at the edge and near the centre
of the scale, and evidently does not grow thicker; it is thus easy to understand that the
winter rirbg-s, for instance, upon the surface of this layer, continue eiiually distinct
many years after formation, in contrast to what is found be to the case witli otoliths,
where the earliest annual rings become entirely concealed, and are only discernible
after the otolith has been ground down so as to expose its inner structure.

An examination of sections also reveals a number of breaks in the upper layer;
these will be found to be the so-called radial furrows {vide plate I, fig. 1), which run like
channels in the surface layer. Finally, it will be seen that the exterior covering layer
extends out beyond the edge of the fibrillar plates and forms by itself, independently
of these, the margin of the scale. The winter rings are not particularly conspicuous
in a section ; despite the most careful orientation by means of the fine ridges on the
surface, it has not been found possible to discern any conspicuous peculiarity in those
parts of the outer layer where the winter rings lie. It is noticeable that the ridges,
which resemble the teeth of a saw, are set somewhat irregularly; possibly, also, the
outer layer itself is slightly thinner in the inner than on the outer side of the point
where a winter ring is situated. These features are, however, so inconspicuous, that
without exact orientation it would be impossible to demonstrate where the winter
rings actually lie in a section. Figs. 9 to 11 give diagrams of various details from
sections of herring scales.

Fig. 9.

Fig. 10.

'rr^^^TTf^^^^r^^

Fig. 11.

Below the (juter ccnering layer may be seen, viewing the scale in section, a
thicker stratum, divided into zones of varying appearance. If the section be embedded
in a medium of low refraction, it may be distinctly seen that the fibrils in some of the
zones have been cut transversely across, whereas other zones are clearer, with less
apparent structure, suggesting that the fibrils here are not transversely severed. This
layer formaticm may be strikingly shown ])y placing the sections in polarized light,
when, in certain positions, a series of bright bands, with darker zones between, will b"
apparent. It will then be distinctly seen that the thickness of the lamella? varies, and,

1 This staining did not succeed, when the scales cut had been treated with acids in order to
remove inorganic matter. I have, by microchemical reactions, satisfied myself of the fact that
practically all inorganic matter (principally phosphate of lime) is in the herring scales deposited
in the outer covering layer, while the fibrillar plates are devoid of it. I suspect that the
differential staining is due to the presence of metallic salts in the one layer only, the salts acting,
as it were, as a mordant.

fi551— 10

90

DEPARTMENT OF THE NAVAL SERVICE

as will shortly be shown, this is,, in all probability, to be regarded as in connection
•with the fact that the lamellse themselves form a system of annual rings, which may
be rendered discernible by preparing the scales in a special manner. If we take, for
instance, fresh herring scales, treated, however, with nitric acid, and impregnate them
with bichromate of potassium, thereafter placing them in a solution of nitrate of
silver, a dark precipitate of some silver compound will be formed between the fibrils.
This precipitate is not amorphous, but is deposited in small spindle-shaped particles,
each with its axis in the direction of the fibrils, so that a preparation of this kind
distinctly shows the course of the fibrils themselves just as the course of currents
is shown on nautical maps. As the impregnation takes place only, or mainly, in
those layers which lie nearest the surface of the scale, it is possible, by gluing the
scale to be impregnated, on to a glass plate, to exclude one of its two surfaces from the
action of the silver solution and thus to impregnate either the innermost lamella?
alone, or only that portion of each, which lies immediately adjacent to the outer layer
of the scale. The operator can thus obtain at will either views as in fig. 12, giving

Fig. 12.

schematically a portion of the innermost lamellse, or as in plate IV, fig. 13, showing a
portion of a scale impregnated from the outer side. This latter shows, in another
manner, the same feature as seen in plate IV, fig. 6, while the former corresponds to
plate III, fig. 4.

On examining a scale thus impregnated, with a low-power lens and in oblique
light, the small spindle shaped bodies will not be discernible. They produce, however,
by reflection an effect as shown in plate V, fig. 14. In this manner, an excellent view
is obtained as to the extent of the elementary lamellse, and it is at once strikingly
noticeable that the breadth of the zones exhibits an irregular progression, broader belts
suddenly appearing after a series of narrow zones. Closer comparison reveals the fact
that the transition from narrow to broader zones takes place just where the surface of
the scale shojvs a winter ring. Thus the elementary plates are seen to form their own
.system of annual rings, corresponding to that of the surface layer, but otherwise
differing' greatly from this, and more resembling that found in the scales of many
salmonoids and gadoids, etc, where the winter rings are not so sharply marked, but
a gradual transition from summer to winter is seen.

The foregoing description as to structure of the scales does not apply to all the
scales found on the body"/ of a herring. On looking through a collection of herring
scales, some will be found to differ from the rest, being most easily distinguishable
from these by the fact that the zigzag boundary line between the two systems of stripes
(vide plate I, fi^g. 1) does not reach right down to the basal line, nnd that the stripes
in a more or less considerable central portion of the scale form irregular patterns, in
contrast to what is normally the case. Winter rings, again, are invariably lacking in
this abnormal central portion, although present outside it, excepting, of course, cases

Plate V.

>/■'

FIG. 15

FIG. 16

-7^

r)551--10.^

92

DEPARTMENT OF THE NAVAL SERVICE

where the entire surface of the scale is abnormal and no winter rings are to be seen.
Plate V, figs. 1.5 and 16 give photographic reproductions of the central portions in a

Plate VI.

'/v/- _..<.

-::■'■ «^^-

n

normal and an abnormal scale from the same fish. Ihe occurrence of these abnormal
scales is highly irregular; on one specimen, numbers may be found, while in another,
long and carrfnl search will be required to discover a single one. It is furtlier remark-

CAyADT.iX FIS^HERIES EXPEDiriOX, lOl'rlo 93

able, that in one and the same specimen may be found scales where the abnormal cen-
tral portion is (luite small, and others in which a larg-e portion, or the entire surface,
is of abnormal appearance.

The same confusion noticed iii the relief of the outer surface is likewise encoun-
tered in the inner structure of such abnormal scales. It will be found impossible to
split them, for instance, as long' as the needle jxtint is introduced within the abnormal
central part, and if the covering' layer be removed, we do not find the regular alterna-
tion of radial fibrillar zones with those having- tangential fibrils; on the contrary,
the fibrils will be seen to intertwine, forming patterns similar to that shown in plate
VI, fig-. 17. If such abnormal scales be treated with silver solution as described be-
fore, it will be noticed that the division into zones, which otherwise makes itself so
distinctly apparent during- this process, is not discernible within a central portion
corresponding to the visibly abnormal portion of the surface layer.

The most probable explanation as to the origin of these abnormal scales would
seem to be as follows. The scale originally set in the scale pocket where now the
abnormal one is found, must on some occasion have fallen out, this' taking place at a
time when the original scale was of a size corresponding to the abnormal portion of its
successor. Within a short time after the loss of the original scale, a new scale (the
abnormal portion) grows out, and then, having filled the vacant place, the scale pro-
ceeds to grow normal wise.

Closer investigations of the scales of a herring, with this question in view, will
soon reveal the fact that the scales innnediately adjacent to an abnormal scale are, as
a rule, themselves abnormal, forming together a group. And outside these
again, or rather round about them, may frequently be found scales presenting another
form of abnormal structure than the first mentioned, the central portion correspond-
ing to the abnormal centre in the first being here either dislocated in relation to the
peripheral part, or at least separated from this by a line concentric with the peri-
phery, and more or less distinctly marked. Outside these scales lie the wholly nor-
mal scales, so that transition stages are seen to lie between the two extremes. In
order to make this clear, a group of entirely abnormal scales was sought for on the
body of a herring, and all the scales surrounding this group w^ere then picked off and
prepared, careful note being kept as to their respective positions. Plate VI, figs. 18a
to d are from photographs showing the central portions in a horizontal series of these
scales, the first giving a view of the last normal scale before the abnormal formation
begins, and the last illustration being that of the first abnormal scale. This series of
views, and similar series which I have had no difficulty in finding, distinctly suggest
that the abnormal scales are nothing but supplementary growths intended to replace
scales previously lost by accident. The scales immediately adjacent have become
slightly displaced from their natural position in the scale pockets, as shown by the
fact that the central portion forms, as it were, a scale upon the scale. It will also be
seen that the transition forms may well give rise to erroneous determinations of age,
the boundary line between the central portion and the periphery frequently bearing
more or less resemblance to a winter ring. This will be further referred to later on.

IV.— THE SCALES AS Al^ INDICATIOX OF ACE. SOURCES OF ERROR

IN ACE-DETERMI X.\ TIOX.

We have no experimental proof of the fact that the so-called winter rings on the
scales of the herring actually are annual rings, i. e., that one such winter ring is
formed each year. On the other hand, statistical observations point so emphatically
to the correctness of this supposition, that it will hardly seem possible to otherwise
explain the regularity revealed by the observations. The observations in question
deal primarily with the Norwegian stock of herring, which have been under considera-
tion in this respect for several years. The proofs thus furnished can, strictly speak-

94

DEPARTMENT OF THE NATAL SERVICE

ing, only be regarded as entirely applicable to the stock in question, and it is of course
perfectly justifiable to demand that in dealing with other races of herring, similar
data should be sought for before assuming that the conclusions arrived at are equally
valid for these. As we shall see later on, the Canadian material, like the Norwegian,
does in fact point to the same conclusion, that the winter rings really are an indica-

Plate VII.

tion of the age of the fish. At present it will suffice to mention, as briefly as possible,
the manner in which the observations were carried out in the case of the Norwegian
herring; it should be noted, however, that corresponding features have been observed
in the case of other stocks of herring, e. g., those of the Faeroes.

In the course of the year 1910, the young herring which were continually taken
in the neighbourhood of Bergen were subjected to observation (vide Lea, X). It was
then found that the outermost summer zone on the scales, which in May was extremely

CAXADIAX FISHERIES EXPEDITION, lUl'rlo

95

narrow, grew broader and broader as the summer progressed, until September, when
a period of stagnation set in. Supplementary investigations have shown that at somo
time or another during the months of ^farch or April, small herring are found, some
of which have only broad summer zones (one or two),, while others have either a broad
inner zone and a very narrow outer one, or two broad ones innermost, and one very
narrow beyond {vide plate VII, fig. 19). Fig. 20 shows schematically the manner in
which the annual rigs were seen to appear at different times of the year. Observa-
tions extending over several years have shown that the small herring taken near
Bergen only exhibit this narrow outer summer zone in the spring, and that the outer
summer zone is in autumn invariably found to be broad.

Continuous observations of this nature will be analogous to the observation of
herring kept in tanks, with periodic examination of the scales. If an experiment of

December 1909

UUimo April 1910

Ultimo May

Ultimo June

Ultimo July

Ultimo August

Medio September

Medio October

Fig. 20.

this kind, with herrings in tanks, were found to give the same results, we should then
certainly be justified in concluding that the summer zones of the scales were formed
and developed during the period, April to September, and that the winter rings in
consequence represent the time from October to March. In the present instance, this
absolute certainty is not attained, since the observations with captured herring
naturally to do not represent different states of the same fish at different times.

During a period of years, from 1907 to 1916, samples of so-called spring herring
were collected, these being the fish which early in the spring move in towards the west
coast of Norway to spawn. Scales of each fish in the samples collected were examined,
and the herring grouped according to the number of rings on the scales. It was then
found that for the greater part of the i)eriod embraced, a remarkable regularity
prevailed, as indicated by fig. 21. This has been lent from Hjort (V) and
shows the percentage of fish (in the samples investigated) falling to each group accord-
ing to the number of rings. It will be seen that in 1908, there were many with 4
rings ; in 1909, 5 ; in 1910, 6 ; and so on until 1914. The investigations of 1915 and
1916 revealed the presence of a large number of herring with eleven and twelve rings,
respectively. This regularity, which, by the way, is also encountered in samples of

96

DEPARTMENT OF THE NAVAL SERVICE

another " kind " of x^orwegian herring, the so-called large herring, can hardly be
explained save by the supposition that a certain year-class of herring have throughout
the whole of the time from 1908 been more numerously represented in the stock than
others, and that as time went on, and the fish grew older, one ring was formed on the
scales for each successive year.

These observations exhibit great similarity to the results in the following experi-
ment, which may be easily carried out with fresh-water fish : A number of fish are
caught, all those with a certain number of rings on the scales sorted out and liberated
in a pond where no fish of the same species are' found. A year later they are recap-
tured, scale samples taken and examined, to ascertain whether the scales now exhibit
one ring more than at time of liberation. They are then again set free, to be taken
up once more a year after for renewed examination. The investigations actually made

3456769 10 1

1 12 13 14 15 16 17 18

1907

'7 A/t-"V_

1908

'0 / /V--^

1909

- Jm

1910

10 ^ /stiA

1911

io___y^ ylj\

1912

^° __— >^ /u

1913

"^^. ^,^<—^ ,^

^ 1914

5 4 5 6 7

Age groups

10 II 12 13 14 15 16 17 18

Fig. 21.

lack the absolute certainly as proof which such a test experiment would have; on the
other hand, the length of the period here embraced, and the absolute uniformity of
the results from all samples, are points of no little weight. Throughout the whole ^f
the time from April, 1908, to February, 1916, not a single sample was found to furnish
any exception to the general regularity. Not until February, 1916, was a sample
brought in which lacked the 12-ringed fish present in such great numbers in
the remaining twenty-four samples from the winter in question. This single instance,
however, does not impair the proof-value of the material as a whole, for the regularity
observed can naturally not be expected to continue indefinitely. On the contrary, it
would be natural to expect that the character of the stock in this respect will in a
short time exhibit noticeable change.

The samples of grown Norwegian herring, from the year 1910, inclusive, contain
a considerable quantity of specimens exhibiting a remarkable arrangement of the
winter rings. As a general rule, the distance between the rincs decreases from the

t'A.\AI>f.[\ Jl^HKRlEi^ EXrEniTIOX, lOl/f-lo

97

innermost outwards to the margin of the scale, as shown in fiji-. 22 a; in the specimens
here in question, however, the arrangement was similar to that shown in fig. 22 h,
where, as will be seen, the third summer zone is narrower than the fourth, reckoning
from the centre outwards. In 1(110, this peculiar feature was especiall.v marked

Fig. 22.

among the 6-ringed fish; in the following year, it was chiefly apparent in the scales of
the 7-ringed specimens; and so onwards. The table prepared shows how these parti-
cular fisklieep together in one group, with a gradual progression of the group as a
whole towards the right of the table.*

Tablk 1. — Distribution of herring with abnormal arrangement of rings on the scales.
Material from grown Norwegian herring, seine caught.

Total

Percent of

ndividuals in

tlie different

ring-classes.

number t)f

individuals
with abnor-
mal arrange-
ment.

^p be

a

'V

o be

a

Year.

t3

CO bo

c

•73

00 ic

a

C5 bo

a

c

^1

si

;.*

'"

u

»

h

u

s-

'"

'-

u

U

^

1910

134
372
322

2-2
11
2-5

91-0

4-8
1-2

4-5

86 3

4-3

'4 C

84-5

0-7
1-3
3 4

0-7
11
0-3

0-7
0 5

"6-3

0-9

litll

191-J

1-9

0-9

1913

217

()-9

0-9

2 3

1-4

3-7

86-7

2-3

0-5

0 9

0 5

1914

518

1-9

3 1

1-9

21

2-7

5-4

79 2

2-1

0 6

0-6

0 4

1915 . .

1291

0-2

23-8

2-8

3 3

1-8

0-7

30

61 5

1-4

0 6

0-3

01

These observations may best be compared with an experiment whicli has already
been carried out in the case of the cod (Winge, XIV). The fish, when caught, are
marked with numbered labels, scale samples taken and tbe marked specimens
liberated, care being taken to select only fish of unimpaired vitalit.v.
After the lapse of some time, some of them are recaptured, and the scales examined,
to see whether new annual rings have appeared in number corresponding with the
lapse of time between first examination and recapture. Instead of the artificial mark
affixed wo have here the peculiar arrangement of the rings as the distinguishing fea-
ture of a group whose scales in a given year (1910) numbered six rings in all. It is
liardl.v likely that an approximately equal percentage of this group would then, in
1911, be fcuind among the 7-ringcd fish, in 1912 among those with eight rings, and so
on, up to to the 12-ringed in 1916, if it were not that a new ring made its appearance
each year.

Scales having the appearance shown in fig. 2*2 h were not found, or found in but
niiiiiuial (|uantities, among the samples of mature fish until 1910. On the other hand.

98 DEPARTMENT OF THE NATAL SERVICE

in 1907-09, these were the more numerous among the samples of immature herring
from the north of Norway, and as might be expected (in view of the fact that the
samples consist of autumn-caught iish)' they are found in 1907 only among the herring
with four summer belts; in the following year, 1908, they appear in large numbers (95
per cent)^ among the fish with five summer belts, and in 1909 among those with six
(79 per cent). In the autumn of 1910, only a very few fish with seven summer belts
were found (seventy-eight in all, out of 1614 specimens examined). Of these, how-
ever, fifty-five ihad scales of abnormal appearance, and these fifty-five specimens
amount, after all, to 40 per cent of the total found.

Consideration of fig. 21 and table 1, leads us directly to the question of possible
error in counting the rings of the scale. What would be the results, for instance, if,
owing to various difficulties, the investigator were unable to note with certainty the
number of rings on a considerable proportion of the scales? Would such inaccuracy
by any means be able to account for a filial result revealing so distinctly marked a
regularity as that here found in the case of the Norwegian herring?

It is no difiicult matter to see that erroneous age determinations will tend to pro-
duce an age curve which, where it should exhibit marked differences in the number of
individuals in the various groups, assumes, instead, a more even contour,, with less
pronounced contrast and more gradual transition between the age-groups. The groups
most numerously represented will give ofi^ a greater number of individuals to the
groups adjacent than they receive from these.

The experience gained in the course of the investigations with Norwegian herring
tends to show that the probability of error is greater when dealing with older fish
than with young specimens, and further, that the error more frequently falls to the
One side, thus placing the fish in a younger year-class than that to which it actually
belongs. And finally, it has been found that the majority of such errors are uniform
in degree, the fish being reckoned as one year younger than is actually the case.

The effect of errors of this nature and degree will then be that, where a certain
sample contains one dominant age-group, the predominance of the group in question
will appear less than it should, and the younger group next following be credited
with greater number of individuals than is its due. We are consequently led to the
conclusion that the figures arrived at in the case of a dominant group are minimal
values, i. e., that the diagram shown in fig. 21i, for instance, would have presented
essentially the same features, but in an even more marked degree, if all the deter-
minations of age on which it is based had been correct.

That errors and uncertainty are unavoidable in investigations of this kind will
be admitted by all who have had any experience of such work. The material may be
handled with the highest possible degree of care and attention, so as to warrant the
hope that a repetition of the determinations must give exactly the same results, yet on
going through the whole once more, discrepancies will nevertheless be found. As n
matter of fact, we are hardly justified in using the term " age-determination " when
dealing with scales ; " estimate^ " would be more correct, for there will always be
found, whatever may be the material under consideration, a greater or less niimber of
individuals whose scales must be classed as doubtful, and where the decision must be
based more or less upon personal judgment.

In this respect, the herring from different localities will be found to vary,, and it
is therefore impossible to formulate any generally valid rule as to how great the
probnbility of error will be. And, indeed, any such estimate would always be a matter
of difficulty. Eepetition, of course, affords a certain guide in this respect, and this
method has also frequently been employed, with satisfactory results, in dealing with
the Norwegian herring. Another method is to examine the actual results arrived at
in the investigation of a certain stock. It would be altogether unreasonable to
suppose, for instance, that the age determination in the case of the Norwegian herring

1 Excluding all fish with less than four summer belts.

CANADIAN FISHERIES EXPEDITION, lOl.'i-lo 99

could ever have been brought to exhibit pecularities so inarked, if the number of
erroneous determinations, a neutralizing influence, had been considerable. As will
be shown later on, the Canadian material furnishes several excellent instances of
consistency in the results arrived at. For the present, it will sutKce to point out that
the material from the Canadian investigations presents, in the case of some localities,
no particular points of difficulty, whereas samples taken elsewhere have included fish
with scales by no means easy to decipher. On the whole it may be said that the
Newfoundland material from the gulf of St. Lawrence is to be regarded as well suited
for the purpose of age determinations, whereas some part of that from the open coast
presents many difficulties. It is of great importance, however, in such investigations,
to familiarize oneself, by long-continued observation, with the peculiarities of the
particular herrings to be dealt with. Valuable aid is also furnished where oppor-
tunity occurs of following the progress of a single age-group from year to year. There
is probably no single circumstance which has so largely contributed to tlie firmness of
conviction, now i)revailing among Norwegian investigators, than the fact of their
having been in a fortunate position to watch the growth of a single rich year-class
throushout an extended period of time.

The greater or less probability of error, or uncertainty, may depend upon various
factors. The sources of error may be divided into two categories : —

1. Circumstances of a purely technical nature. The technical methods
employed in dealing with the material are of considerable importance, and will
therefore be described at greater length later on.

2. Conditions independent of the technical treatment, i. e., such as will
make themsdlves apparent even when the most adequate technical methods are
employed. In this case, it is generally a question of fish whose scales have the
winter rings indistinctly marked, or which exhibit fainter intermediate mark-
ings between those normally legible, or again, as with older specimens, the
outermost rings so close together as to render them difficult to distinguish.

Where the winter rings are not sharply defined, they frequently present the
appearance of several very thin lines, one outside the other, in the form of a faint
band. Such double or manifold rings would seem to be of most frequent occurrence
among those earliest formed; a type of scale very commonly met with is that where
the outermost rings are rather clearly mai'ked and easily distinguishable, while the
inner one, and possibly the next few, will be vague and double. How far this may be
connected with the spawning, as tending to render the rings more sharply defined,
cannot be stated with icertainty,, but it is not unlikely that such is the case.

The fainter rings occasionally found between the true ones have been termed by
Dahl (I) " secondary rings ", and are so distinguished in the present report, albeit
the term might well be taken to embrace various kinds of rings. I was at first of the
opinion that the position of all kinds of these '* secondary rings " varied from scale
to scale, and that their disturbing influence might therefore be eliminated by examin-
ing a sufficiently large number of scales from each fish. Objections to this have,
however, been raised by Hellevaara (IV), who considers that secondary rings may be
found, the position of which corresponds on the different scales of a fish — being, how-
ever, in some scales almost indistinguishable.

As to the origin of the secondary rings, nothing ean be said with certainty. The
dislocated scales described on p. 93 show, however, that a slight shifting of the scale
from its normal position may occasion the formation of secondary rings. In other
cases, faint shadows, produced by the inner fibrillar plates, may be seen. Plate VI,
fig. 23, reproduces a photograph of a scale exhibiting such shadows. Where the winter
rings are faint or doubled, it may be conceived that these shadows may become of
some importance as sources of errors.

With regard to the close-set outer rings in older fish, there is little to be said,
save that as the rings lie closer and closer with increasing age, we have here a limit

100 DEPARTMENT OF THE ^^ATAL SERTICE

to the possibility of approximately certain estimates of age. In the Canadian mate-
rial, some herrings were found which must certainly have been older than any which
I have examined among those from European waters, their age being over 20 years.
Where a definite age is assigned to them in the tables, this must expressly be noted as
approximate; in cases of this sort accurate determination is out of the question.

Finally, mention should be made of a particular source of error which needs to
be guarded against by special precautions.

In a sample of herring collected just at the time when the fish are developing
the first stages of a new summer zone on the scales, some specimens of a certain year-
class may be found where this has already visibly commenced, whereas others of the
same group have not yet reached so far. If, then, the rings be counted quite schema-
tically, and the observations recorded accordingly, the results will be that fish which
have already commenced their summer growth will appear a year older than those
which, albeit somewhat behindhand in this respect, are in reality contemporary with
the former, and the greatest confusion will ensue.

In many cases, e. g., in dealing with young herring, the change is more or less
conspicuous and the error may be avoided ; as in such specimens, a narrow summer
zone is visible outside a broader one, or several such. It is a different matter, however,
when the fish are older, and have already one or more narrow zones near the margin
of the scale. A new narrow zone on such a scale does not occasion any conspicuous and
easily disting-uishable alteration. In this latter case, it is difficult to say what precau-
tions should be taken unless it be to avoid collecting samples during this transition
period, or, possibly better, to supplement such samples by others taken before and after.
The grown Norwegian herring, it may be noted, are not regularly fished for during
the transition period.

V. THE SCALE OF THE HERRING AS AN INDICATION OF GROWTH.

SOURCES OF ERROR.

If, in addition to counting the winter rings on the scales, we measure the dis-
tance between them, these measurements will enable us to calculate how each fish has
grown from year to year. This, of course, presupposes that the growth of the scale
takes place at a rate simply proportionate to the rate of growth of the fish. Judging
from the investigations already made (vide Lea IX), the scales from various parts of
the body differ somewhat in this respect. On the whole, however, we may say that such
proportion does exist. ♦

It has been found, however, that in dealing with the material obtained from such
measurements of growth, the values arrived at in the case of j'oung fish appear to be
higher than the corresponding figures for the older groups (vide Lea XI and Lee XII),
so that possibly there may be a systematic error in the growth measurements.

This is, in my opinion, only true to a certain extent. Moreover, some part of the
apparently systematic error will, as a matter of fact, be found to arise from other
causes, to wit, as the results of a biological process. Nevertheless, we may, in prac-
tice, until these problems are fully solved, do well to handle our material as if there
were a systematic error, of the nature shown in the following taW?:^ —

CAXADiAX Flail i:nn:>i kxi'fditiox, loi't-io

101

T.\ni.i: 2. — Showing the decrease with increasing age of the corresponding calculated
average values for the yearly inoremciit in loiiiith. (Table reprinted from
T.ea (V) tab. 7.)

Year of capture.

Age.

No. of
samples.

No. of
indivi-
duals.

h

ti

5-8
5-2
5 0
51

4-8
3 7
3 5
3 5

U

h

U

ti

1907

1908

1909

191U

4^

2
1
3
6

69

.58

331

78

7-2
7 1
71
6-9

4 7*
4 2
3 9
3 9

"39*
3 4
2 9

32*

28

'2 b*

* l>eiiote incompleted increments.

In the table above, t, indicates increment of leii°^th during first summer of life,
t.. tlie corres])onding increment for second summer, etc. It will be noticed that the
figures in the vertical columns exhibit decreasing values, and that a growth curve
drawn on the basis of the figures for fish at 3* years would differ from one based on
the values for fish 6J years old. This feature, which is very freiiuently encountered,
may render immediate comparison between the growth values for young fish and those
for older specimens precarious ; therefore, where possible, samples of herrings of more
or less equal age should be compared.

As regards the degree of accuracy obtainable in such individual measurements of
growth, this is fairly high, and it is always possible, where greater accuracy is needed,
to measure several scales from the same fish and take their average. This branch of
the question need not therefore be further dealt witb here. It should, however, be
noted that all the sources of error which make themselves apparent in age determin-
ations also apply to measurements of growth. If a ring be overlooked, then two years
growth will be taken together as that of one, and the growth of the succeeding years
will be erroneously reckoned, etc. If, on the other hand, a secondary ring be mistaken
as a true one, the year's growth will be divided into two, and that of the following
years again incorrectly recorded.

Save in the case of particularly diffii-ult scales, however, errors of this nature
will rarel.v occur in the values for growth during the first few years.

VI. AGE DETEmnXATIOX AND (JROWTM MEASUKEMEXT TX PR.VCTICE.

Where the winter rings are distinctly marked, and the fish young, it is of little
importance from what part of the body the scales are selected; in the reverse case,
however, this may be of the utmost imi>ortance. In all the scales of a herring the
winter rings are by no means equally distinct. Where possible, therefore, the scales
where these are most pronounced should always be chosen, i. e., the large scales from
the middle forepart of the body.

VII. PREPARATION OF SCALES FOR PRESERVATION.

In the earlier years of the Norwegian investigations, the herring scales were
scraped from the body with a knife, and placed in small envelopes, where they gra-
duallv dried. Before being used, they were soaked in a soap solution to which gl.vce-
rine was added, which afforded a good enough means of cleansing them. This is a
practicable method, and even presents certain advantages, when working on the fishing
grounds, or on board a vessel under unfavourable conditions. Of late years, another
method has been employed; three scales are plucked out with a pair of tweezers, clean-

102 DEPARTMENT OF THE NAYAL SERVICE

ed while still fresh, then dipped in clean water, and laid in their wet state on an
object glass, upon which have been placed three small drops of white of egg and gly-
cerine (half and half), one little drop to each scale. Care must be taken that the
scale lies with its inner side against the glass. When the water has evaporated, the
scales will be found adhering firmly to the glass, and a permanent preparation is thus
cbtained. Notes as to length, weight, etc., may be made on the glass itself with water-
proof ink (India ink to which is added some water-glass).

A third method of extreme simplicity is merely to take a single scale from each
fisli, and place it in a tube of water, to be mounted later. Tubes are kept for each
length-group, or for each length-group and either sex, and the scales are then placed
each in the tube assigned to its particular length and sex. Each scale in a given tube
thus represents a fish of a certain sex and length and may afterwards be mounted on
glass slides. By t3iis means, a large sample of herring specimens may be dealt with
in a very short time; it involves, however, the necessity of dispensing with data as to
weight, state of development of genital organs, etc.. besides lacking the indubitable
advantage conferred by having several scales from the same fish. The advantage of
the method lies in the fact that it enables the operator to procure a large qiiantity of
material for age determinations in a short space of time, and that it may be employed
even under the most unfavovirable conditions. Moreover, where no examination of
the specimens is made as to sex, the fish are entirely unharmed.

Microscopical examination. — As we have seen in the description given in the
foregoing of the structure of herring scales, the impression of the winter rings is
produced by reflection and refraction of light in the outer surface of the ocale. In
accordance with this, it has been found that no colouring, or similar process, will serve
to render the rings more distinct than they naturally appear. The most that can be
done is to alter the conditions of reflection and refraction by embedding the scale in
a more or less highly refracting medium, experience having shown that this does
render the winter rings more easily discernible. For examination of herring scales,
a medium with not too great power of refraction has been found most useful, water
with a little glycerine, or alcohol (90 per cent) is good, the latter being preferable
when the scales have been mounted with the white of egg and glycerine, as aqueous
liquids tend to loosen the mounted scales.

In observing scales through the microscope, a suitable attachment should be
used, preferably an objective so arranged that the power can be altered at will. Leitz'
objective la and Reichert's objective Ih are both very convenient, as with these the
power may be continuously changed within certain limits.

In age determinations, it is best to remove the condenser from the microscope,
and leave the lighting to the plane mirror alone. It is rarely possible to obtain suit-
able lighting of tlie entire scale simultaneously, and the mirror must therefore be fre-
quently moved. The rings are best seen in slightly oblique light, when they show up
darker than the summer zones {vide plate I, fig. 1).

In counting the winter rings, the operator should make it a rule to commence at
the margin of tke scale and work inwards towards the centre, i. e., first counting the
rings which are most difficult to distinguish.

Where several scales have been preserved from each specimen, it is well to make
a preliminary glance at all those which are ready prepared, and choose the one in
which the rings appear most distinct. When the rings on this have been counted,
another scale may be taken as a check, to see if the same number and arrangement of
the rings is also fouiid there.

Instead of counting the rings on the scales, it is nossible, by means of a drawing
mirror, to outline them on paper and count them afterwards. Such a method pre-
sents several advantages a^so as regards the actual determinations of age. and it is
a question whether the method should not be adopted in most cases. It is best to
use a drawing mirror with a series of smoked glasses for regulating the light. In

CA\ADIAX FISHERIES EXPEDITION, 1914-15

103

order to render the picture of the scales as distinct as possible, a background of black
paper should be laid on the table to the right of the microscope. It will not be necess
ary to draw the entire contour of the winter rings; all that is needed is to mark tlu*
position of each ring along the edge of strip of a card, as shown in fig. 24. The can!

Fig. 24.

is laid on the table beside the microscope in such a manner that, to the eye, viewing
both card and scale in the mirror, the corner of the card falls exactly upon the centre
of the scale, the corresponding long side of the strip lying almost at right angles to
the basal line. If then each winter ring, and the margin of the scale, be marked off
along the edge of the card, a graph is obtained, presenting a magnified picture of the
growth of the scale. Multiplying all these dimensions by a factor which renders the
distance from the corner of the card to the mark for the edge of the scale equal to the
length of the fish — this can be easily done grai)hicany as shown in fig. 25 — we have

/

/

/

cm

5h-

^3-

\^

^^

sXMiJ^

2S-

^^^^S.

28-

^^^^fe..

27-

^^^

26 -

^^tj^

^w

2S-

^

"^WV

2t-

^><^^k.

2J-

^^^^.

22-

^^^pfv

21-

^^^^V

20^

^'^^

19-

>;^

■8-

^V^s.

■«;

^&^^^

1 ,

,18-

"^ ^^

^^i^^v

l'?^

^^ ^^

1*-

"•~~.. ^~-

^

13-

^.^

^^

^%^

.

12-

■"■ ^^ ^^ ^^

^•ift

^N,

11 -

^^ — .

"^*^^

10-

^^*

"^ ^

-^^^^

9-

~ -^ ""-^

^^

a-

■-•*» ^"^ .^

"

-^

^iv

7-

-^^^^

■* —

^^' '^s.

6-

^

^ ■

^.^

^^

s.

5-

--.

^ -^

^^v

5-

^"^

''''"^^l^^k.

2-

1 -

"^^%

Fig. 25

104 DEPARTMENT OF THE NAVAL SERTICE

the length of the fish at the times the different winter rings were formed. This entire-
ly graphical method of measuring the growth of each individual specimen will natur-
ally not give such accurate figures as those obtained by the more exact, but less rapid,
methods of measurement and calculation; both the use of the mirror and the subse-
quent graphical multiplication involve the occurrence of errors which can of course,
be diminished by the application of more exact methods. For most purposes, how-
ever, the method will be found sufficiently accurate.

VIII. DEFINITIONS AND ABBREVIATIONS ADOPTED.

Various expressions and signs employed in the following pages will need to be
defined.

1. Age. — Age is expressed by the number of annual rings which have been found
on the scales of the specimen in question, the relation of time of capture to season of
birth being, however, here taken into consideration whenever possible. Thus a herr-
ing taken at Newfoundland in the spring will, if its scales show, say, ten summer belts
be reckoned as 10 years old, whereas one from the same place, but taken in the autumn,
and with ten summer belts, will be regarded as about 9J years eld, having regard ti)
the spawning season at Newfoundland.

2. Age-group. — In assigning a specimen, say, to age-group 10, this is to be under-
stood as meaning that its scales showed ten summer belts, ignoring the fact, when
nothing is stated, as to whether it was taken in early spring or late autunm. The
term is therefore used without regard to season of birth or time of commencing new
summer growth.

3. Year-group. — When a fish is assigned, say, to year-group 1910, this means,
that the specimen in question probably formed its first summer belt in that year. For
all fish spawned in the spring, the date of the year-group will be identical with that
of the year of birth ; in the case of those spawned later, however, towards the autumn,
it will remain open as to whether or not they formed any summer belt during the
remainder of the year in which born. Fish taken during the period of transition to
new summer growth may be difficult to class correctly in their proper year-group, and
personal judgment will here be brought into i)lay iridp \). 113).

4. Growth-dimensions. — On the basis of growth measurements, we obtain for each
specimen figures indicating its calculated length at the time of forming first winter
ring. This calculated fir^t winter length is noted as I,, while similarly, the calculated
lengths or time of formation of second, third, and subsequent winter rings, will be
designated by ?^, I., etc. Subtracting Z, from L, we obtain the calculated increment
of growth during the time falling between the formation of the first and second winter
rings, this increment being denoted by i, and similarly, /,=?, — L t^^^l^-^l„, etc.

f). Length. — By the length of a herring is understood the distance from the point
of the snout to midway between the extreme points of the tail-fin when naturally
extended. The length may be measured in millimetres or centimetres, and a fish is
assigned to its nearest length-group; thus all fish, between the limits 29-5 and 30-5 cm.
length, will belong to the 30 cm. group.

IX. COLLECTING OF MATERIAL.

The methods of individual age-determination and growth-measurement naturally
suggest themselves as aids to the statistical investigation of the biology of the herring.
If, however, they are to be used for this purpose, it will be necessary to formulate pro-

CANADIAN FISHERIES EXPEDITION, 191>rl5 105

blenis suitable for treatment by statistical methods of work, and to procure adequate
observation material for statistical investigations. The question as to what problems
can be dealt with will largely depend upon the possibilities of obtaining material for
observation, in which respect, different waters will be found to vary, as we have here
to reckon both with the technical features (implements used, intensity of the fishery,
etc.) and also with natural conditions, which are not every^vhere alike. In the case
of each area investigated, therefore, it will be necessary to test the possibilities and
limitations of the methods, i. e., to gain experience by actual application of the
methods on the spot, and to utilize the results obtained by the work in determining
the possibilities of continued operations, and in drawing up plans for the same. On the
other hand, such determination will naturally be facilitated when it is possible to
compare the results of preliminary investigations in a new area with the experience
furnished by similar work elsewhere, which renders it easier, for instance, to distin-
guish between generalities and specific local features. In the following pages, there-
fore, an attempt will be made to sum up conclusions as to the possibilities for obtain-
ing material of a typical and representative character acquired during the Norwegian
herring investigations, which have now continued over a period of ten years.

First, as regards the age composition of the Norwegian herring stock, the inves-
tigations distinctly show that the stock in question does not appear as an even mixture
of every possible age-group; on the contrary, it is seen to be divided up into several
more or less markedly separated groups. These groups correspond in some degree to
the various " sorts " of herring, as known and distinguished by the fishermen, and the
appearance of the various groups at different places and times gives rise to various
kinds of herring fisheries. The most distinctly defined group is that containing the
mature fish, known by the fishermen as "large herring" when taken before spawning,
•and "spring herring" when captured on the spawning grounds and ready to deposit
their spawn. Another group is the " fat herring," which may be characterized as
herrings of moderate size still immature, and of excellent quality, whence the name.
A third group is that of the " small herring," i.e., small, young, immature fish, of
poorer quality than the fat herring. The habitat and migration of the various groups
are evidently different. The spring herring, for instance, crowd in to the west coast
in enormous numbers during the first months of the year. The fishermen have a
characteristic name for these close-packed shoals; they call them " sildebjerg "=a
" bjerg " or mountain of herring. It is a rare thing to find a young, immature fish
among these masses of mature, " full " herring. And on the other hand, fish with
genital products already developed are rarely found among the fat herring taken in
the northern Norwegian waters during autumn.

The individuals in a year-class move up, so to speak, from group to group as time
goes on, and as their development proceeds. The movement, however, does not take
place simultaneously in all individuals, so that a particular year-class may become
divided up, and fish of the same age will be thus encountered at different places and
times, in association with those of various other ages. The Norwegian herring mate-
rial offers several instances of this spreading of a year-class over different groups. In
1908, 1909, and 1910, fish of the 1904 year-class were found both among the mature,
full, herring on the west coast, and among the immature fish in the northern waters,
vide Hjort (Y) and Lea (XI). The investigations upon immature herring, in 1915,
showed that a distinct age-group occvirred within a restricted area, and at the same
time, associated partly with younger, partly with older, but still immature fish. This
feature will be seen illustrated in table 3.

It is apparent from table 3, that the fish 2i years old are in two samples
associated with almost exclusively older fish (one year older) whereas in the two
others, they are found in company with others, almost without exception younger
(one year younger). In the one case, they make up about two-thirds of the total
number in the sample; in the other, less than a third.

6551—11

106 DEPARTsMENT OF THE NATAL SERVICE

The recognition of this important phenomenon leads us to the conclusion that
an investigation of the age-distribution in a herring stock should include a study of
the different groups, and that the interchange between them should be most attentively
observed. One of these groups, that comprising the mature fish, has been under
observation for ten years in Norway. The experience gained during the course of
the work distinctly points to the possibility of following the age-composition, and its
variations, within this group. These investigations have, in methodical respects
especially, furnished interesting results; a brief description and discussion will
therefore here be given of the material collected for the study of this age-composition
and renewal of the mature group.

During the first years, from 1907 to 1913, only a small number of samisles, from
two to four, of the true full herring were collected annually, with, in addition, one to
three samples of the so-called large herring, i. e.i, mature fish with genital products
large but firm, which we now know to be very closely related to the actual spawning
herring. Despite the small number of samples, and of specimens investigated, the
samples were found to agree so closely one with another, and the features observable
with regard to age-composition so marked as to convince the investigators at work on
the material that even these few samples, and this small number of specimens, might
yet be taken as representative, so far related to a certain very important point in the
distribution of year-classes in the group of mature Norwegian herring. The main
point in question was the fact that the year-class 1904 exhibited a marked numerical
superiority over all others.

This year-class made its first appearance in any great number in a sample from
April, 1908. It was thereafter found, in every single sample investigated during the
years in question, to be enormously superior in numbers to all other year-classes. The
striking contrast between the numbers of this one year-class and those of the many
others, and the fact that this contrast was maintained for several years, served largely
to confirm the conviction in the minds of the investigators. In order to give the
surest possible foimdation for the observations;, a larger number of samples was
collected during the folio-wing years, from 1914 to 1916. The analysis of this material
confirmed most emphatically the presumption already arrived at, the year-class 1904,
despite its continually increasing age, being still found to occupy a dominant position.
One sample from the southern verge of the spawning grounds (Ivristiansand, February,
1914) contained, besides the 1914 year-class, another numerically strong age-group,
that of 1908 (vide Hjort V), but as this peculiarity was not obsers-ed in subsequent
samples from either the same area or elsewhere it was presumed that the sample in
question only represented a slight local disturbance occasioned by the immigration of
a new year-class, which supposition was later confirmed. The winter season 1914-15
passed, and still the 1904 year-class, with its now 11-year-old fish, was seen to pre-
dominate. The first samples then investigated, however, already indicated that the
1910 year-class would now come to occupy a distinctive position, being more numerously
represented than the adjacent classes, albeit far from equal in this respect to the old
1904 class. At first, also, there was but a slight degree of uniformity between the
different samples as to the numerical value of this new year-class. Not xuitil the
commencement of March, 1915, was it seen to be evident beyond question that this
year-class was decidedly richer than its older neighbour 1909, and in the two last
samples of the season, it even rivalled 1904, the last but one containing 48 per cent
1910 and 25 per cent 1904, the figures for the last sample being 33 per cent and 38 per
cent, respectively.

With these results in mind, the following season would appear to be doubly
interesting; in the first place there was the question, would the 1904 year-class, now
no less than 12 years old, continue to assert itself as heretofore; and, secondly, would
the new year-class, maintain the same distinctive position as in the two last samples
from 1915, or fail to maintain it as had been seen in the case of the 1908 sample from

CA^'ADIAN FISHERIES EXPEDITIOy, WL'rlo 107

Kristiansand. The first nineteen samples of large herring, in the winter of 1015-lt},
presented the same appearance as noted so many times l>efore, the year-class 1904 being
still predominant, and that of 1910 represented by only a few specimens. The twen-
tieth sample, however, the first of the true spring herring, was a great surprise, as it
contained one single specimen only of the 1904 year-class, and was otherwise composed
mainly of young fish. 6. 5 and 4 years old. i.e.. the year classes 1910 (with 26 per
cent), 1911 (18 per cent), and 1912 (43 per cent). Here, then, was the 1910 year-
class, but associated with two younger ones, of which the class 1912 especially was
present in force. The following spring herring samples (from February, 1916)
reverted once to the old style of composition, with 40 to 50 per cent 1904, but in
March this is gradually changed, and we have first the 1910 year-class, and later the
1912 class, accompanied by the less numerously represented intermediate year-class
1911. Fig. 26 shows the entire series of age-analyses for seine-caught spring
herring, the previous series of drift-net-caught large herring samples is here omitted
for want of space, but may be supplied by imagining the nineteen earlier samples of
fairly the same character as Nos. 2 to 4 in the figure.

A glance at the figure will show that the group of mature fish must have under-
gone a thorough change during the course of the season. At the commencement,,
there were evidently two very different sub-groups (represented by samples 1 and 2-4),
As the season goes on, however, these intermingle, so that the curves for age-distribu-
tion exhibit a highly peculiar appearance. Altogether, the different samples agree
very well one with another, and this despite the fact that the situation this year was
highly variable, and not, as hitherto, practically stationary.

The entire material of mature Norwegian herring, it will doubtless be admitted
distinctly indicates as possible the statistical recording of age-distribution and its
variations in this group of the stock. The results arrived at in methodical respects
from analysis of this material is, that the year-classes which have passed over into the
group in question become so thoroughly mixed that it is possible, even with relatively
few and small samples, to keep trace of the condition, when the same is, as during
the years 1910-13, mainly stationary. During periods where marked alterations take
place, as in 1908, 1914, 1915i, and 1916, the number of samples will need to be greater,
in order to furnish a view of the actual changes occurring. Thus, in 1916, no single
sample can be taken as representative of the conditions, and erroneous conclusions
would certainly have resulted had not several samples been available from various
parts of the season, and different fishing grounds.

It is interesting, from a methodical point of view, to consider somewhat more
closely samples from those periods when new year-classes began to make their appear-
ance. We have here, first of all, the immigration of the 1904 year-class, in 1908 ; then
that of the 1908 class in 1914; the 1910 class in 1915; and finally, the year-classes
1910-12 in 1916.

The 1904 year-class was first observed among the mature fish in 1907,. but only
in very small numbers; in 1908, it is found in the first sample from February, although
not numerously represented ; in the next and last sample from this season, however,
it makes up 65 per cent. In the sample from 1909, it amounts to about 40 per cent,
i. e. a decrease in the proportion. This rule, a rise of the percentage to a maximum,
followed by a fall, applies to all cases where investigation has been made. The 1908
year-class appeared on the south coast at first in great numbers, later on in the same
year the percentage was lower. The 1910 year-class reaches a maximum in the penul-
timate sample from 1915, with 48 per cent, in the last sample from that year percen-
tage is only 33 per cent. The immigration of a new year-class, and the intermingling
of the same with the older components of the stock, evidently takes some time, and
wovild appear to commence with the entrance of the immigrants in a body, which
wedges itself into the stock already on the grounds within a restricted jwrtion of the
same. The absence of the 1910 year-class during a great part of the fishing season

6551— Hi

108

DEPARTMENT OF THE NAVAL SERVICE

JCBC gi-oup 1915 12 11 10 09 OS 07 06 05 04 05 02 01 00 18»»
Age group 5 4 3 6 7 * <) 10 11 12 15 14 15 It 17

Age group 3 ^ ^6 7 6 9 10 H 12 li I-* 15 '6 17
.T»«r groi,p 1914 12 11 10 O* 08 07 06 05 04 05 02 01 00 1899

Fig. 26.

CANADIAN FISHERIES EXPEDITION, 191.'rl5

109

1915-16 also seems to suggest that the process of mixing is gradual and may require
some time, in other words, the group comprising the mature fish can at certain
periods be more or less heterogeneously composed, as was the case to a very high degree
in 1916.

Inv'estigations as to age among the Norwegian herring have been carried out
under favourable conditions, inasmuch as it has been possible to obtain samples not
biassed owing to tho methods of capture employed. Obviously, when gill-nets are
used, some doubt may easily arise as to whether the age-distribution, apparent in a
sample, may be more or less a result of the selective effect of the net itself, and a
sample of such netted herring cannot be credited a priori with the same representative
value as one taken with the fine-meshed seine. It was therefore fortunate for the
Norwegian investigations that the herring fishery of Norway happens to a great ex-
tent to be carried on by seine (shore and purse-seines), and these more reliable seine
samples furnished a starting point from which to investigate those taken in other nets.

The best means of carrying out such investigations would probably be to set nets
of different mesh out in a standing seine. This would furnish excellent material for
the purpose. Unfortunately no such experiments have hitherto been carried out, and
for the present, all we can do is to utilize the material available, and compare seine
samples with net samples taken at approximately the same place and time. In so
doing, however, we have to reckon with a disturbing factor, to wit, a certain relation
existing between time and place of capture, on the one hand, and implement on the
other. Thus drift-nets are employed for the capture of herring out at sea, and espe-
cially early in the season ; the whole of the " large herring " fishery is carried on with
drift nets. The shore seine, on the other hand, can only be used when the fish come
close in to land. Stake nets, again, are fixed on the bottom, while the purse-seine is
worked near the surface. The Norwegian material includes a number of paired sam-
ples more or less satisfying the above requirements. These are set out in pairs in
table 4 so as to permit of comparison between the age-composition in the samples.

Table 4. — Comparison between samples from seine and net-hauls. Each net sample
compared with the seine sample nearest adjacent in point of time and place.

Localitj'.

Svinfihavet.
Gursko. . . .
Karnisund. .
Rovccr

Karrnsund

Skudf^nes. .......

Inside Skudeiies.

Date.

Mar. 5, 1914
„ 26, 1914

Feb. 19, 1914
M 13, 1914
., 19, 1914
M 19, 1914
•, 18, 1915
,. 22, 1915

Gear.

Age

—Group.

Net.
Seine

Xet

—

4

0-9
1 1

5

2-3

3-1
1-9
2-5
15
2-0
2-5

(

2
2
5
3
3
3
4
5

1

3
2

5
7
9
5
1
1

7

4-6
7-7
0-2
30
5-4
40
8-2
8-0

8

50
8-4
100
50
5-4
5-4
5 4
4-7

9

13-9
l!l 4
16 6
'2-1
14 7
11 4
8-2
5-9

10

56-9
51-6
50-8
62!
60-5
60 7
17 0
8-9

11

4?
5-5
3 9
71
3-4
6 ••
53 1
61 5

12

2-8
1-8
1-4
1-6
1-7
1-0
1 4
1-3

13

3- 7
lo

1-8
19

0-

2 5

14

1-9
0 4

'o':>

811
0 5

15

0 9
0-4
0 7
0-7
0-3
1-5

16

Seine

Net

0-3
1-5

'o'7

Seine

0-8

0-8

0 4

The general impression given by the table is that the columns of net-samijle fig-
ures resemble very closely those for the seine-caught fish, such discrepancies as occur
being small and without apparent regularity. Particularly interesting are the
columns for the samples for Karmsvuid and KuvaT, where tiie two seine samples are
from hauls made on the same day and quite close together. The impression, furnished
by such paired comparisons between seine and net samples, leads us to the conclusion
that the age-composition of mature Norwegian herring has been very much the same
in the netted samples as in those taken with the seine. The same result is arrived at
if we consider the material as a whole, the whole of the netted material tending in the
same dir<^ction as that furnished by the seines. And bearing in mind the fact that

110

DEPARTMENT OF THE NATAL SERVICE

the samples as a rule include more than ten age-groups, this result cannot but be said
to be surprising. It might easily be imagined, for instance, that the difference in
size between the younger and the older fish would be so considerable as to involve a
degree of net selection far from negligible, the smallest and largest specimens avoiding
capture, whereby the net samples would be seriously biassed. That this proved not
to be the case, with the Norwegian samples of mature herring, is due to an important
biological phenomenon, which we shall now have occasion to examine more closely,
in considering the question of how best to procure representative material for the
study of growth.

As already mentioned, the individuals in a year-class may fall into several sub-
groups, appearing in company with older or younger fish. This subdivision of a year-
class does not appear as merely accidental, but seems on the contrary to be regulated
in a definite manner according to the stage of development at which the fish have
arrived. This is, of course, natural enough in cases where some individuals of a year-
class attain maturity and are ready to spawn, while others are still immature. Noth-
ing could be more reasonable than to suppose that the mature fish should part com-
pany with those of their contemporaries that have not reached that stage, and move
off by themselves to the spawning grounds. The year-class is thus divided up anrl
dissociated according to the degree of maturity of the genital products. We now find,
however, that the mature individuals in a year-class thus divided are of larger — often
considerably larger — size than those still immature. There exists a positive correla-
tion between degree of maturity and size. The year-class thus divided according to
degree of maturity will therefore also be found dissociated according to size, the
larger specimens of such a year-class will be found associated with older, mature fish,
the smaller with younger, immature companions.

This being ascertained, the question then arises as to whether the attainment of
maturity should be regarded as the only phases of development accompanied by such
dissociation in point of size among the individuals of a year-class.

Table 3. — Age distribution (showing percentage) in four samples of immature

herring from northern Norway, autumn 191.5. Group 3 (2§ years old fish) are

in two samples found in association with older herring, and in two samples
with younger herring.

Locality and Date.

Nnmber of
individuals
in sample.

Per cent belonging to different Age-Classe.s.

s

3

group 2

group 3.

group 4.

groui)5.

1

2
3

Kvaefjord, Oct. 15, 191.5

ariittavfer, Oct. 20, 1915

Ibestad, Nov. 7,1915

KvEefjord Nov 11 1915

Ifi9
194
259

205

%

0 6

2-6
88-0
68-3

%
74-0
03 9
120
31-3

%
24 9
320

0 4'

%
0 6
1-5

The answer here must be that the dissociation already mentioned (vide table 3) is
also regulated according to size; we find, for instance, that the average length of the
2J-year-old fish (group 3 in table 3) is considerably greater in the two first samples,
where this age-group was associated with older fish, than in the two last, where it was
found in company with younger fish (22-1, 22 -61, 17-0 and 18-3 cm., respectively).
The four samples in the table are from hauls made within a restricted area, the
greatest distance between places of capture being about 40 km. and within a short
space of lijne, vi?., from 15th October to 11th November. An even more striking

CAXADI.iy FISHERIE^^ EXPEDITIOy, 191',-lo

111

example of this size-regulated dissociation, among immature fish, is furnished by two
samples from hauls made at an interval of eight days and 21 km. apart. Table 5
shows the age-distribution in these two samples, and the difference between the average
sizes of the year-class 1913.

Table 5. — Showing difference in average size of herring belonging to the same year-
group (1913) in two samples. In one sample the herring considered were found
associated with younger herring, in the other with older herring.

Locality and date.

No. of

indiv id. iu

.sam pie.

254
177

Percentual a^e composition.

Average

length of

group 1913.

Year gr.
1914.

Year gr.
1913.

Year gr.
1912.

Year gr.
1911.

Bergsvaag, Trondences, Sept. 10 .
Tennvik, Sept. 18

89 0
0 6

11 0
63-3

" "35-6

o'e

IG .0 cm.
227 ..

Finally, it should be mentioned, that mature, full specimens of the same year-
class were also found among the spring herring in the spring of 1916, the average
size of these was 25-8 cm., or considerably in excess of that found in any sample of
immature herring, where the maximal average size was 22-7 cm. Neither the differ-
ence in size nor in degree of maturity, can easily be explained as a result of growth in
the period between late autumn 1915 and the spring of 1916, the discrepancy being too
great, the time too short, and the season, as has been shown by experience, being a
period of stagnation. It is therefore most reasonable to suppose that the said year-
class was dissociated into at least three groups, one consisting of small fish, associated
with younger ones; another of large, but immature individuals associated with their
seniors; and finally one comprising those of large size and completed maturity,
associated with the adults.

The remaining two important year-classes in the material, viz., those of 1914
and 1912, do not exhibit fluctuations so violent as in that of 1913; there is, however,
also here a suggestion of dissociation according to size, wherefore it would be well to
reckon with the possibility that a year-class may become dissociated and grouped
according to size of individuals throughout the entire period of growth until full
maturity is attained.

What takes place after this time, when all surviving individuals of the year-class
have reached maturity, cannot be stai;ed with certainty as yet; there is, however, reason
to believe that the process of maturing should be regarded as a phase of development
which, when completed, leads the separate components of a divided year-class to
reassemble, i. e., that the sub-groups formed by the varying rate of development will,
after maturity and subsequent spawning, reconsolidate into a whole.

At any rate, it would seem, from the results of the Norwegian growth investiga-
tions, that the components of the rich year-class 1904 — which, from its numerical
importance and pecularities of growth, furnishes excellent material for a study of this
question — did reassemble after their separation during the process of attaining matu-
rity, and were later found mingled and collectively in the samples of mature fish.
The observations made from year to year present, when seen together, the picture of
a process terminating in a fairly stable mixture of the heterogeneous elements which
compose the year-class in question. This is especially noticeable in the case of that
growth-dimension which exhibits the greatest and most peculiar variation, viz., the
increment for the third year of life (^,). Fig. 27 shows curves of frequency for this
dimension, the observation? of each year being noted separately, and subdivide'1 into

112

DEPARTMENT OF THE NAVAL SERVICE

1 ' 2, 3 -<► 5 6 7

Fig. 27. Mature herring. . ,

a 9 10 cm.

Immature herring.

CA:^ADIAy FISHERIES EXPEDITIOy, 19Vrl5 113

two categories, the one embracing a sample from the spawning grounds taken during
the spawning season (the spring fishery of the west coast) and the other including
immature fat herring taken in autumn on the north coast of Norway.

It will be noticed that the individuals found among the grown fish in 1908 have
a considerably greater t^ than the autumn-caught immature fish from the north, a
similar difference is also observable in 1909. In 1910, however, the curve for the ma-
ture fish exhibits a different course, and is here distinctly bimodal ; during the autumn
of the same year, only a few specimens of this year-class were found among the im-
mature fish, and the following year none. After 1910, the curve maintains its pecu-
liar form, with the two modes, the position of which, as will be seen, corresponds to
the two modes in the two pairs of curves for 1908 and 1909.

Similar conditions will be found to apply in the ease of the remaining growth
dimensions (^i t2 ti fs) save that the original difference between the two categories is
not so great as to produce a final bimodal curve, but only a compound curve.

From the foregoing, it will be seen that the biological process which is termed
the dissociation of year-classes is a phenomenon which must be taken into consideration
in statistical investigations of the growth (and age) of herring. The phenomenon
itself would seem, as far as can be judged up to the present, to be of considerable
dimensions, and to be closely related to other phenomena such as maturation, migra-
tion, accumulation of fat, etc. It is therefore, in my opinion, worthy of closer study,
in the prosecution of which growth measurements may be of assistance, in view of the
relation between dissociation and size (growth).

In the case of investigations dealing with the problem of growth during different
years, or in different waters, the phenomenon will appear as a complication, a new
and variable factor. It will therefore be necessary, in such investigations, to procure
material, the elements of which are as far as possible comparable. And as circums-
tances are, the best material would be that consisting of older fish, as offering greater
facilities for the procuring of representative samples.

With regard to the question as to number and size of the samples, it will be seen
from the foregoing that various points need to be taken into consideration here. The
number of samples, and their size (i. e., the number of individuals contained) must
be determined according to the peculiarities of the stock to be dealt with, or of the
water under investigation, or of the problems which it is desired to solve. In the
case of the immature Norwegian herring, for instance, where, as we have seen, the
year-classes occur in several combinations, and dissociated according to size, a large
number of samples will be necessary; owing to the small number of year-classes re-
presented, however the samples need not be particularly large. The mature Norwe-
gian herring, on the other hand, in 1914 might, as we are now able to see, have been
dealt with through fewer samples than were collected, owing to a comparative stabi-
lity in the distribution of the year-classes with a single dominant group, which mark-
ed this year, as compared with the variability of the situation in 1916, where several
new year-classes cropped up.

A water area containing several different tribes of herring will in particular re-
quire a larger number of samples than one where simpler conditions prevail.

In dealing with problems which demand that the values operated with (e. g.. the
mean values for growth dimensions) shall be accurate, i. e.. with the smallest possible
degree of accidental error, it may be necessary to make the sample larger.

It is impossible to lay down any definite rule or system for determining this ques-
tion, as the circumstances to be considered vary from place to place and from time
to time. In most cases, however, we may say that given a certain niimber of speci-
mens to be examined, there will be more chance of obtaining the best material when
these are distributed among a largen number of smaller samples, then if they are
massed in one or a few large ones. In the Norwegian investigations among the
grown herring, the material was at first collected by taking a few samples each year,

114 DEPARTMENT OF THE NAVAL SERVICE

each sample containing a relatively large number of specimens. As the work went on,
however, it was found desirable to collect the material on a more extensive basis, with
more samples, distributed as widely as possible throughout the area and the season
embraced by the fishery. This involved an alteration of the methods employed, and
a number of the samples thus collected were now subjected to a simpler process of
examination (vide p. 133) in addition to which the question as to possibility of reduc-
ing the number of specimens in each sample was considered and tested. With this
new method, which was tried and adopted in 1914, it was found that for the object
in view, and under the conditions then prevailing among the stock, comparatively
small samples might well be used. An average of some 200 specimens per sample was
seen to be sufficient, and it was also realized that the advantage gained by operating
with larger samples would be altogether disproportionate to the extra work involved,
as the discrepancies between the samples could not be essentially minimized thereby,
and may be due to other causes than fluctuations of sampling.

It should be emphatically pointed out, however, that the prevailing situation was
exceptionally favourable for the work of age investigations, the contrast between the
one enonnously rich year-class 1904, and all the others, being so great that the curves
for age distribution would maintain their characteristic appearance even with con-
siderable errors of sampling. In other words, the age composition was so characteris-
tic, that it was advantageous to work with small samples, and consequently greater
accidental fluctuations, as this rendered it possible to deal with a greater total number
of samples.

In cases where the age distribution is less characteristic, e. g., where several
successive year-classes are more or less equally strong, accidental fluctuations of
samples may impair the agreement between the samples, or at any rate, render it less
obvious. In such cases, therefore, it may be desirable to reduce the extent of the
fluctuations of sampling by increasing the number of specimens in each sample. It
was in anticipation of such a possible change in the situation that the number of
specimens per sample was increased to about 400 in the case of the Norwegian spring
herring investigations in 1916.

The situation prevailing during the past few years among the Norwegian spring
herring has not been quite so favourable for growth investigation; when so great a
percentage of the specimens examined is derived from a single year-class, the result
is an almost superfluous quantity of material confined to the group in question, with
a corresponding reduction in the amount for growth observations for the many other
year-classes represented. Under these circumstances, it would require a dispropor-
tionate amount of work to procure material in which every single year-class should be
represented by the full number of specimens desirable for growth investigations.

CAyADIAy FISHERIES EXPEDITIOX, lOl'rlo 115

B. SPECIAL.
THE CANADIAN MATERIAL.

X, Description A^D pkeluiinary grolpixg of the Caxadux materl\l.

The chart, lig. '2>i, ou page 117 will serve to locate the samples placed at my dis-
posal and dealt with in this chapter. The material comprises a large number of
samples from au area embracing the Atlantic coast of Canada, the gulf of St. Law-
rence, and the coast of Newfoundland.

The comparatively large number of samples, and their distribution throughout
different seasons, counterbalances, at any rate in the case of certain waters, the dis-
advantage arising from the fact that the number of individuals in each sample is, as
a rule, but small. It will, however, probably be desirable in the case of future investi-
gations, to secure larger samples, as the stock in these waters has been found to in-
clude an unusually large number of age-groups. Nowhere have fish of so great age
been found in such considerable numbers as here.

Bj' far the gTeater portion of the samples originates from catches made with
implements, viz., gill-nets, which cannot be regarded as particularly suitable for the
purpose ol obtaining representative material. As mentioned in the foregoing, samples
of netted herring must necessarily be less reliable tlian samples taken with non-select-
ive implements, especially where no opportunity occurs of making comparison, as in
Norway, with samples of the latter sort. Some doubt may therefore arise as to whether
the younger and smaller fish are represented in their due proportion in the sam-
ples. There are, however, as will subsequently be shown, certain peculiarities in con-
nection both with age-distribution and growth, which cannot be explained as merely
resulting from the selective effect of the nets.

In addition to the samples of grown herring from various places and taken at
various times, we have also a number of samples of young, immature fish, drawn
partly from catches made by steam drifter No. 33 with the drift-net, during the sum-
mer of 1915, and partly also from trap-catches. The importance of these samples of
immature herring lies not so much in their representative value, which may be oi)en
to considerable doubt, not only on account of the method of capture, but also because
the experience gained in the course of the Norwegian investigations has shown that
some caution is necessary when dealing with samples of quite young herring. They
form, however, a valuable supplement to the material of gro^vn fish, as furnishing an
aid to to the determination of the time when summer growth begins, and also because
it has been found that these young fish exhibit growth variations for the different
waters exactly similar to those noted in the case of the grown individuals. These
young samples, therefore, add to the value of the remaining material, and give the
results a more general character.

From the very first, on going through the scale-samples it was strikingly evident
that the material must embrace several different, in some cases strikingly different,
"sorts" of grown herring. The difference between fish from the different localities
made itself apparent partly in the more or less distinct marking of the annual rings
on the scales, rendering number and distance more or less easy to read, partly in the
fact that the dominant age-groups (year-classes) differed in samples from different
localities, and finally, in the different character of the growth, as indicated by the
scales. It therefore seemed natural, after this first survey, to make a preliminary
division of the material according to locality. This gave four groups of samples, as
follows : —

116 DEPARTMENT OF THE NATAL SERTICE

1. Samples from the waters about Prince Edward Island, i. e., west and
south of a line drawn from cape North, Cape Breton, to the eastern point of
Prince Edward island, and thence on to cape Gaspe in the province of Quebec.

2. Samples from the waters about Magdalen islands.

3. Samples from the coast of Newfoundland (all from the west coast, ex-
cepting one from White bay).

4. Samples from the Atlantic side of Cape Breton island. Grand Narrows,
Ardoise, coast of Nova Scotia, Bay of Fundy, and from Gloucester, Mass.

The following pages will be devoted to a description of the results obtained from
i.ge-determinations and growth measurements, arranged on the basis of the above
group-division. The first question to be dealt with will be, how far fluctuations occur
in the relative numerical value of the year-classes, and if such occur, whether they
become apparent in the same manner throughout the entire area embraced by the
samples, or whether they vary in the different waters. Thereafter, the growth in the
various localities will be discussed. And finally, by summing up the information
obtained from the study of the age and growth, and discussion of the material avail-
able as to number of vertebrae, etc., an attempt will be made to deal with the question
as to the possible existence of different races or tribes of herring in the Canadian
waters.

XL— AGE.

a. The tvaters about Prince Edward Island.

From these waters we have fiv^e samples of grown fish, taken by gill-net at different
places in Northumberland strait; two of these are from May, 1914; the remaining
three from May, 1915. In addition to these, there are also two samples of herring
caught in traps in the neighbourhood of Souris during the summer of 1915, and eight
samples from drift-net catches made during the cruises of the drifter No. 33 at various
places in the gulf, in June and July, 1915. The chart, fig. 28, shows the localities.

The trap-and drift-net catches contain a quantity of young specimens, and on
examining scales from these we find as will subsequently be shown, that the summer
growth for 1915 commenced some time in June in the case of the young fish, probably
during the second half of the month. It will therefore be reasonable to suppose that
the older and grown specimens in the samples from May had then not yet commenced
their new summer growth, and that, consequently, the last summer zone in the scales
would represent the growth of the fish during the summer of the year previous t^
capture.

The other samples, containing older fish, date from the time between the end
of June and the end of July. With regard to these therefore, we cannot be so sure as
to whether summer growth has commenced, or if so, whether it has commenced in all
cases. Some doubt arises in assigning the fish to definite year-classes (vide p. 119),
in addition to which the length of drift-net used by No. 33 was composed of greatly
varying widths of mesh, and thus rather calculated to take herring of all sizes than to
take them in the natural proportion between the different size-groups. The value,
therefore, of the samples in studying the proportions of the different year-classes is
somewhat difficult to determine, and the samples of grown fish from Northumberland
strait have consequently been kept apart from the rest. Fig. 29 shows the percentual
age-distribution in these five samples.

It will immediately be noticed that the implements have here succeeded in
capturing fish of most widely differing age, from specimens 4 years old to individuals
of (apparently) some 20 years, a circumstance resembling that noted in the case of the
drift-net hauls of Norwegian grown herring, but in the present instance perhaps even
more marked. And although we here lack such means of gauging the value of the

CANADIAN FISHERIES EXPEDITION, Idl.'rlS

117

samples as is afforded by comparison with samples taken with non-seleetive imple-
ments, yet the circumstance in question gives us further grounds for hoping that the
fish of medium age at any rate have been taken in something like their natural pro-
portion. This presumption is further confirmed on examination and comparison of
the curves for the different samples. Here, as will be seen, the different age-groups
are represented in by no means equal numbers, and what is more, the samples them-
selves agree in this respect to a degree which, considering the small number of si>eci-
mens and the largo numbers of age-groups, may be taken as very satisfactory.

Fig. 28.

The curves being age-curves, there is, of course, transposition from 1914 to 1915
of the two characteristic modes; in 1914: there are comparatively many fish aged 7
and 11 years, in 1915 many of 8 and 12 years old, whereas the age-groups 6, 8, 9 and
10 in 1914, and 7, 9, 10 and 11 in 1915 contain relatively few specimens.

In the case of the younger fish, we do not find the same agreement in the different
samples. It must in all probability be taken as due to accident that we find, for the.se
ages also, an almost perfect agreement when we take the two 1914 samples! together
as one. and compare the resulting age-curve for the whole with that for the three 1915
samples together. This is shown in fig. 30, where the grouping is arranged according
to year-classes, and not in order of age.

118

DEPARTMElsT OF TEE t^AYAL SERVICE

Age classes

4 5 6 7 8 9 10

II 12 15 14 15 16 17 18 19 20

-I 1 1 1 1 1 I 1 I 1 1 1 I

Northumberl.
5tr.

1914

2°^ 110 Individ
10

Pictou Hr 1915

CAyADIAX FISUEKIEH EXPEDITIOX, Wl-Ho

119

It will be seen that the 3'ear-classes 1903 and 1907 were considerably more nume-
rously represented in the samples than the other year-classes, and especially charac-
teristic is the difference between the " good " year-classes 1907 and 1903, on the ono
hand, and the three intermediate years 1904, 1905, and 1906. The older year-classes
are represented by few specimens, whereas the younger ones, as mentioned, vary from
one sample to another.

The small number of specimens and of samples, and the nature of the implement
of capture, are points which diminish the representative value of the material. On
the other hand, the marked degree of similarity between the samples, the characteris-

1911 10 09 08 07 06 05 04 05 02 01 00 1899 98 97 96 95

■ 30 %

- 10

19U

218 ind ivid

1915

525 Individ.

1911 10 09 03 07 06 05 04 03 02 01 00 1899 98 97 96 95

Fig. 30.

tic transposition of the modes of the curves for 1914-15, and not least, the peculiar
course of the curves themselves, are features which must be taken as favouring the
supposition that the peculiarities noticeable in the material actually reflect typical
conditions. A bimodal or multimodal age curve will probably, as a rule, arise not
on account of, but despite the selective effect of the implement of capture.

We cannot, however, take it for granted that net samples, even though exhibiting
variations in the relative strength of the year-classes, present these variations in their
correct numerical proportion. If we cannot be sure that the nets have taken the
younger year-classes (1911-1910-1909) in their due proportion, neither can we be cer-
tain that the two strong year-classes are correctly represented in this respect, the nets
might well be supposed to have retained a relatively greater number of the one group
than of the other, owing to the difference in size. This question could be decided by
continued investigations, or by procuring material from hauls made with non-solect.ive

120

DEPARTMENT OF THE NATAL SERVICE

implements. A slight step in this direction may be made by considering the samples
taken during the cruise of No. 33 and the samples from Souris. Most of the samples
contain many young and immature fish, but, in five, some old fish were found,
viz., in the samples from stations 27, 28-29, and 42, and also in one of the trap samples
from Souris. The three first stations are situated between the western side of Prince
Edward Island and the Gaspe coast, while station 42 lies north of cape George {vide
chart, fig. 28).

Table 6. — Age distribution in three drift-net samples taken off the Gaspe coast
(stations 27-29), one trap sample from Souris, P.E.I., and one drift-net sample
from west of Port Hood, Cape Breton (station 42), June, 1915.

Locality and Date.

Station 27, 48° 21' N., 63" 57' VV., June

28-29.
Station 28, 47° 56' N., 63" 27' W., June

29-30
Station'29, 47" 34' N., 64° 12' W., June

30July 1.

Souris, June 7 . . . .

Station 42, 46^ 0' N., 61° 56' W., June

15-16.

Number

of
individ.

82
30
95

117
133

Age-groups — Year-groups.

3 4 5 6 7 8 9 10 11 12 More

1912

1-2

3-3

3-2

25-6
07

1911

13 4
40 0

68-4

36-8
64 7

1910

1909

9 8

67

3 2

60
38

1908

1907

13-4

3 3

h 3

6 0
15

1906

1905

4-9
6-7

4 :^
07

19f4

6 1
100

26

1903

3 3

Table 6 shows the percentual distribution of year-classes in these samples. As
already mentioned, there may be some difliculty in determining whether new summer
growth has commenced in the case of the older fish. In these samples the scales of
some of the younger specimens distinctly show an incipient new growth, whereas in
others, judging from the breadth of the last summer zone, it would seem that the
new simimer growth had not yet commenced. This being the case with the younger
fish, one would hardly expect the scales of the older fish to exhibit any commencement
of new summer growth, and, as a matter of fact, the last summer zone on these old
scales was found to be of about the same breadth as the previous one.

The age-tables have therefore been drawn up accordingly, and the column farthest
to the left thus includes specimens, some of which exhibit the number of summer
zones indicated in the heading, and others an additional narrow zone beyond this. In
by far the greater number of the older specimens (from group 7 and upwards) the
last summer zone on the scales is taken as representing the summer of 1914. This
method of arrangement should, as regards all that is here essential, be correct enough,
albeit some doubt may exist in the case of fish of a medium age.

It will be seen from the table that the fish assigned to the 1903 year-class are
relatively numerous, especially in the samples from station 27 ; in three of the samples,
the specimens assigned to 1907 are relatively numerous (stations 27-29, and the samples
from Souris). The sample from station 42, on the other hand, exhibits no resem-
blance to the five gill-net samples from Northumberland strait ; this sample we shall
later on have occasion to consider in another connection, and it is merely mentioned
here in order to note its difference from the samples from Northumberland strait.

All samples from these waters point, when taken together, to the correctness of
the svipposition that the 1903 and 1907 year-classes were present in greater numbers
than the intermediate year-classes of 1908, 1909, and 1910.

CAyADIAX FISn FRIES EXPEDITION, lOl'rlo

121

With regard to the younger fish, it is not so easy to arrive at definite conclusions
on the basis of the material available; it is always, moreover, a far more difficult task
to ascertain the relative strength of the different year-classes among immature
herring.

Nevertheless, a glance at tables 6 and 7 will immediately reveal the fact that only
a few specimens of the year 1912 year-class were tiiken, whereas the 1911 and 1913
year-classes were particularly well represented.

Table 7. — Showing age distribution in samples where young and immature fish

predominate.

Locality and date.

>

1

38
73
47
47
33
32

Age -groups.

Ypar-groups.

2

3

4

5

6
1910.

' 55

28- 1

More.

1914.
37 5'

1913.

789
520
830
1000
42 4
3 1

1912.

18 4

8-2

17 0

57-6
21 9

1911.

' 3o'i

9 4

Station 33, 48" 13' N. 63" 58' W. July 5-6.
.. al, 47° 52' N. 63° 57' W. ., 1-2.

34, AT 13' N. 64° 21' W. „ 6-7.

35, 46" 51' N. 64° 25' W. „ 7-8.
Souria „ 1 1.
Station 53, 45' 46' X. 62= 23' W. .. 30-31.

2 7
4 1

h. The waters about Magdalen Islands.

From this area, we have a gill-net sample taken in May, 1914, one from May,
1915, and further a very small sample (which is of no value in this connection), with
finally, one from a drift-net haul made by Xo. SS about end of July. 1915 (station 49).
It will be as well to deal with this last sample first, as an examination of the scales
here shows that the younger fish (4- and 5-year-olds) therein contained, had doubtless
commenced a new summer's growth but had made only very slight progress therewith
the new summer zone appearing in most eases as a very narrow belt outside the
broader zones for the previous years. This would seem to indicate that the summer
growth in these waters begins late, as is also the case farther to the west and south.
In the case of the two samples from May, 1914, and 1915, therefore, we may take it
that the last summer zone on the scales represents the summer previous to the year of
capture. For the older fish, however, in the July sample mentioned, it will be a matter
of doubt whether these have commenced their new summer growth or not. In table
8, therefore, only the two youngest age-groups have been assigned to year-classes, the
headings for the older groups indicating only the number of rings on the scales.

Table 8. — Age distribution in samples from station 49, 70 specimens. Year-class noted

only for the youngest fish.

Age-groups

Year-groups.

5

6
1910.

7

8

9

10

11

12

13

14

1911.

1909.

1908.

21-4

14-3

7-1

37 1

2 9

2-9

2-9

71

5-7

14

6551—12

122

DEPARTMENT OF THE NAVAL SERVICE

It will be seen from the table that a considerable number of specimens belonged
to the 1911 and 1910 year-classes, and many fish occured with eight rings on the scales,
with finally a more indistinct accumulation of individuals in groups 12 and 13.

If we now turn to the two samples from May;, 1914 and 1915, we find, as shown
in fig. 31 that one from 1914 contained many 11-year-old fish, while in 1915 there were
many of 12-years-old. The 1903 year-class that is to say is relatively numerous in
both samples. In the 1915 sample, moreover, there were many specimens of the 1911
and 1910 year-classes, a feature common to this sample and that from station 42,, and
as regards the 1911 year-class, also to the several of the samples from the waters
between cape Gaspe and Prince Edward Island. On the other hand, in these two

Age classes

5 ^ b 6 7

9 10 11 12 15 1i^ 15 16 17

samples from the Magdalen islands, we do not find that quantity of fish belonging to
the 1907 year-group which was so characteristic of the samples from Northumberland
strait. What signifiance should be attached to this point of difference it is impossible
to say until further material is available; one thing, however, is certain; the samples
from the Magdalen islands exhibit no small likeness to those from Northumberland
strait and from off the Gaspe coast.

It is therefore open to doubt whether the division here made is in accordance
with the actual conditions, which question will be discussed when the growth investi-
gations have been dealt with, and in connection with the treatment of racial characters
(number of vertebrae, etc.)

c. The Ne%vfoundland waters.

The material from these waters comprises five samples from the spring of 1914,
four from the autumn of the same year, and three from the spring of 1915, making

CAyADIAX FISH t: HIES KM'KDiriOS, 191 'rlo

123

twelve samples in all, of grown fish, all caught with the gill-net. In addition to these,
there is also a sample of quite young herring from the cruise of the steamer No. 33 in
the summer of 1915; this sample however, isolated as it is, will be of no importance
as regards the questions here dealt with. The samples are all from the west coast,
with the exception of one from White bay.

Figs 32, 33 and 34, present, in graphical form, the results of the age determina-
tions, the material being here divided into three groups, according to season.

/^ge groups

10 11 12 15 14 15 tfe 17 18 19 20 21 27 21

Spring 1914

White Bay . pnmo May
156 mdivid

Bay of Jslando, spring
■72 indiv.d

George Bay spring
53 'ndivid

Georges Bay primo May

S? Georges Bay orimo '^zy
156 ndivid

Fig. 32.

The Xewfoundland samples, like those from the ^Fagdalen island and Xorthum-
berland strait, include a considerable number of age-groups, the age of the specimens
varying from 4 to over 20 years. Only very few of these groups, however, are at all
numerously represented; in all the samples save one, the fish are found for the greater
part massed in a particular group, to wit, group 10 in the spring samples from 1914,
and group 11 in the later ones. Taking it for granted that summer growth in these
waters, as in those farther to the south in the Gulf, has not eonmienced by May, then
the age-group 10 will in the spring of 1914 answer to the year-class 1904, and similarly
presupposing that the new growth commences some time during the summer, then
age-group 11 in the autumn samples from 1914. and those from the spring of 1915
will be likewise equivalent to year-class 1904. All the samples, with the single excep-
tion named, thus bear witness to a state of things similar to that noted in the case
of the Norwegian stock, i. e., a single year-class taking up a dominant position, which

6551— 12i

124

DEPARTMENT OF THE NAVAL SERVICE

is maintained for several seasons. Fig. 35 shows the distribution of the year-classes
during these three seasons, as revealed in the samples, the single divergent sample
from 1915 is here omitted, but will be referred to later on, as it is of considerable inte-
rest. We have noticed, in the three foregoing figures, that no essential difference was

Fig. 33.

/\ge qroupi

^ 5 6 7 8 9 10 t1 12 I i 14 15 16 17 18 19 ?0 ?1 2? a

■ 50 %

A

■ 40

/ \ Spring 1915

■ iO

/ A\

• 20

/ / \\

1,0 ^

/ / \ \ Bay ot Jslands May £
1 \\ 115 individ

■ 20%

/ \

'° y

/ \ Bonne Bay May 11
\ 106 individ

20% A

10 /^\/ \_^^^

__y/ \ 5' Georges Bay May 27
\ 102 individ

i, 5 6 7 8 9 10 11 12 13 14 15 16 17 16 1« 20 21 22 2S
/\qe groups

Fig. 34.

apparent between the samples from different localities. Here again, in the present
case, the samples from the three seasons are seen to differ but very slightly one from
another, save perhaps for the fact that the autumn samples seem to include a greater
number of jouns; fi.'--h than those from the spring. The difference, however, is by no

CAXADIAX FISHERIES EXPEDITIOX, 1914-15

125

means considerable, and it is possible, moreover, that the part of the curve indicating
the numerical value of the young fish may in reality be not altogether accurate, owing
to the nature of the implements employed. As a matter of fact, therefore, nothing
definite can be said as to the relative frequency of the young fish here.

The age-groups in the samples have, as already indicated, been carried over into
year-classes; this is analytically supported by consideration of the age-curves result-
ing from the spring samples from 1914 and the autumn samples of the year, with the
similarity between these latter and those from the spring of 1915, distinctly pointing
to tlie fact that the new summer growth must have commenced some time after the
month of May. The strong contrast between of 1914 and groups 11 and 12 in the

Year groups

1911 10 OV 0» 07 06 05 0* Oi 02

00 1899 98 97 96 95 9<. 9J 92 91

Spring of 1914
512 individ

Autumn ot 191A
462 mdivia

Spring of 1915
219 mdivid

1911 10 09 08 07 06 05 Ct 05 02 01 00 1899 98 97 96 <»5 <><, 95 <i-^ 91
Year groups

Fig. 35.

spring of 1915 suggests that the summer growth has not made itself apparent on the
scales at that time of the year. Had such been the case, the contrast would certainly
have been effaced by the division of each year-class into two age-groups, according as
they had or had not commenced their new summer growth. The divergent sample might
possibly to some extent be explained by supposing that some of the individuals therein,
contained had commenced new summer growth; the sample in question was also taken
late in May. But as will later be shown, it is more likely that it represents another
group of herring than those in the remaining samples. This sample apart, the mate-
rial presents an apparance totally different from that furnished b.y the samples from
^Magdalen islands and Xorthumberland strait; moreover, as we shall now have occa-
sion to show, it differs likewise in point of age distribution from that collected on the
Atlantic coast. i ' .

126 DEPARTMENT OF THE NATAL SERVICE

d. From Cape North southwards along the Atlantic coast of Canada.

The material from these waters embraces seven samples of mature herring, and
four of immature fish, covering a range from Sydney, Cape Breton, to Gloucester,
Mass. In going- through the scale preparations from these samples, it was strikingly
noticeable that the scales were considerably more difficult to read than those of the
specimens from the gulf of St. Lawrence. The first and second winter rings were often
found to be faint, thus rendering less distinct the contrast between the true winter
rings and the secondary rings, which latter were of frequent occurrence in these
scales. The rings beyond these may be said to be fairly distinct, but the outermost
ones, on old scales, were again difficult to discern owing to the fact that the fine ridges
on the surface of the scales were often irregularly developed, a symptom of senility
in herrings. Another feature, which will be more important in connection with the
growth investigations, was the frequent irregularity in the proportion between longitu-
dinal and lateral growth of the scales. I have made no measurements in this respect,
but it could often be seen that the scales had during the last few years grown more in
breath than in length, thus rendering the distance between the winter rings relatively
greater, at the two sides of the scale, than in the anterior portion.

The pecularities here noted in the scales of herring from these Atlantic waters
tend to give the investigator an impression that the fish in question must have lived
and grown up under conditions widely different from those which obtain among the
herring in the gulf of St. Lawrence; true it is no easy matter to tabulate and sys-
tematize such features, as distinctness of winter rings or frequency of secondary
rings, the appearance actually presented is, however, none the less remarkable on
examination of the scales. In estimates (and growth measurements) this means
increased labour, and greater uncertainty in the results obtained.

With regard to these difficulties, there appears to be some difference between the
samples from the northern parts of the waters in question, and those from Nova
Scotia, the scales of herring from the more southerly localities being less easy to read
than the others. The material is too limited, however, to i>ermit of any definite
statement in this respect, as much depends upon the quality of the scale preparations.

The difficulties are most felt in dealing with older fish, for the younger specimens,
up to 8 years old, it may safely be said, that a fairly accurate age determination can
be arrived at, with continued investigations, also, and by great care to make the scale
preparations as perfect as possible, a similar degree of accuracy may be attained in
the case of the older fish. Fortunately as matters stand, the material from Nova Scotia
includes only one sample with many old fish; in the others, young specimens pre-
dominate.

As regards the northern samples (North Sydney, Main-a-Dieu and Grand Narrows)
we have the further disadvantage that they were taken during May and June, i. e., at
a time when the herring in these waters may be expected to be commencing their
summer growth. And, as we here lack the support afforded by study of the quite young
fish, and as the samples themselves do not form any series in point of time, it is diffi-
cult to assign the specimens to definite year-classes. In table 9, therefore, where the
results of age-determinations for these three northern samples are shown, the speci-
mens have only been arranged in the age-group, or as one might say, " summer-zone
groups ". As far as it is possible to judge, however, the great majority of the speci-
mens in these samples have not yet begun their summer growth.

CAXADIAX FISHERIES EXPEDlTTOy. lOl'rlo

127

Table 9. — Showing age distribution in samples from Cape Breton, north side. New
growth probably not commenced, so that group 4 should correspond to year-class
1910, in the 1914 sample, and to year-class 1911 in the samples from 1915.

Lo ty and date.

Main-a-Dieu, May 1914

North Sydney, June 3, 1915...
Grand Narrows, .Tune 2, 1915.

Number

of

individuals.

54

98
88

Age-groups.

1-9
5 1

18 2

9-3
12 2
27-3

3 7
01
91

HI

24 5

4-5

7 4

10 2
10 2

9 10 11 12 More

7-4

8-2

10 2

14 8
10
3 4

31-5
17 3
12 5

7 4

12-2

2 3

4 6
2 0
2 2

The sample from Main-a-Dieu, 1914, and that from North Sydney, 1915, have this
point in common, that groups 10 and 11 in 1914 and groups 11 and 12 in 1915 contain
a relatively large number of specimens. These should presumably be the 1904 and
1903 year-classes. The similarity is not, it is true, either here or elsewhere, remarkably
great, but we have to consider the small number of individuals in the one sample.
The sample from Grand Narrows has, like that taken at the same time from North
Sydney, a large number of fish with five rings, but diifers not a little from this ; there
is, however, here again some massing of the 11 and 12 group fish.

% »

■ ^° A

/ \

/\ Bay of 5' George

• 10 /V \

/ \ May 27 1915

^"-^-Z \ 102 indiv

\ .^/•'•^ ■*-*^

0/ A

/o A

•20 / \

/ \

|\ North Sydney

^°/\ / ^

/ \ June 3 1915

/

\ / \ 98 mdiv

4^ S 6
Age group

10 11 12 13 Vt 15 16 17 18 19

Fig. 36.

On the other hand, if we compare the sample from North Sydney with the one
divergent sample from the Newfoundland area, taken a week earlier, we find the most
perfect agreement. The curves for these two samples will be seen in fig. 36. The
striking agreement between these two samples, on the one hand, and the exceptional
position occupied by the Newfoundland sample among the remainder from that area,
on the other, greatly tend to support the presumption that these two samples represent
one and the same group of herring, in which the age-comix)sition is widely ditferent
from that of the Newfoundland fish. The two samples in question will therefore be
more closely compared in the chapter on growth.

128

DEPARTMEXT OF THE NATAL SERVICE

From West Ardoise, farther to the south, we have two samples, both from 1914,
one, however taken in July, and the other in August. In these the scales may pretty
safely be said to exhibit new, and in some eases, fairly advanced summer growth. It
is therefore possible to group the fish in year-classes, as has been done in table 10.

Table 10 — Age distribution in two samples from West Ardoise, Cape Breton. July
and August 1914. Mature and ripening herring.

Locality and date

Number

of

individuals.

104
125

Year-groups and Age-groups.

1912
3

i-G

1911
4

GOG
42-4

1910

5

7"7
19-2

1909
6

1-9
2 4

1908

7

6-7

21G

1907
8

3-8
2-4

1906
9

2-9
40

1905
10

6-7
1-6

1904
11

5-8
3 2

1903

12

10
1-6

More.

West Ardoise, July 1914

Aug. 10, 1914. . . .

2-9

It will be noticed that the samples include a' considerable number of year-classes,
the younger fish, however, predominating. The 1911 year-class in particular is dis-
tinguished by its high numerical value in both samples. In the one from August, the
1908 year-class is also fairly strongly represented, and the same is the case, albeit to
a lesser degree, in the July sample. In the former also the 1910 year-class is like-
wise good. The older fish are too poorly represented to permit of any decision in their
case.

The curves for these two 1914 samples, and in particular that for the two together,
exhibit strong resemblance to the curve for a divergent sample from the area first

^fear g coups

1912 11 10 00 08 07 06 05 04 05-1*93

%

1 1 • > 1 ) > •

.50 .

.0 \

... r

y West Afdoise 1914

■ 20 K

\ 229 Individ

■V/\

\ /\ ^

% /

\

• 30 /

\ St 42. W of Pt Hood 1915

. 20 /

\ 153 individ

• 10/

^'-^'X^

1912 11 10 09

"Seer group

08 07 06 05 04 05-l«9S

Fig. 37.

described, viz., that from station 42 (west of Port Hood and north of cape George)
taken July, 1915. The likeness will be seen from fig. 37. As in the case of the diver-
gent sample from Newfoundland, it mvist be left for future investigations to study
this question more closely.

The next sample in the series is one from the Atlantic coast of Nova Scotia, taken
in August, 191.5. This sample has been dealt with by Dr. Hjort in his preliminary

CAXADIAX FISHERIES EAPEDITIOX, IDl'rlo

129

report. On comparing Dr. Iljort's and my results in the case of this Pample, it was
found that we agree as regards the young fish, but not in respect of the older one.s,
Dr. Iljort having on the whole counted fewer rings on the scales of old fish than I.

T.xBLK 11. — Sample of large and old herring from Nova Scotia, August, 1914, present-
ing difficulties as regards age determination. The table shows the results
arrived at by Dr. Hjort after his preliminary examination, compared with the
results of Lea's two analvses

Age-groups.

5

6

7

8

111
2 9
4-4

9

311
15 8
10 1

10

17-8
16-8
ltj-9

11

11-9
26 6
30-5

More.

Hjort's analysis, 13.5 individ

Lea's analysis in. I, 13!)

II, 138

30
1-4
15

5 9
2 2
1-5

16 3
16 6
15.9

3 0
19-4
20 3

These different results may be compared, in table 11, which further shows that my
first estimates, when compared with an analysis subsequently made, likewise reveal
some discrepancy in the case of the older fish. The scale preparation for this sample
not being perfect, and the difficulty in the case of older fish being, as already men-
tioned, considerable, all that can be said as to this sample is that there were a large
number of old fish and that age-group 7 (year-class 1908) is well represented as com-
pared with the neighbouring groups.

Table 12.— Age distribution in a sample of immature herring from Halifax, X.S.,
and a sample of mature and ripe herring from Lockeport, N.S. Autumn, 1914.

No. of
indivi-
duals.

82
269

Year-class(

33 and

ige-classes.

Locality and date.

1912.

1911.

1910.

1909.

1908.

7

1907.
8

1906
9

1905
10

1904
11

1903
12

3

4

5

61
27-9

6

More.

Halifax, X.S., Oct. 14, 1914..

9-8
0 4

84 2
48-3

3 3

'6-3

Lockeport, N.S., Nov. 1914. .

1-5

11

2-2

4 5

1-9

2-6

Besides this sample we have also one from Lockeport, Xova Scotia, taken in Nov-
ember, 1914, consisting of mature fish, and another from Halifax, October 1914, with
immature fish. Table 12 shows the age distribution in these samples. The sample of
mature herring shows an unmistakable likeness to those from Ardoise, its best year-
classes being 1911, 1910, and 1908. In the sample of immature fish, the 1911 year-
class is very numerously represented.

The two samples of small herring from the Bay of Fundy and Gloucester, Mass.,
present no features of interest in this connection; they contain quite young herrings
with one to three summer belts on their scales.

Taking a general survey of all samples from the Atlantic coast, we find, it is
true, a somewhat complicated picture with much varied detail, nevertheless, one
cannot fail to see that these samples reveal certain definite featurei= upon which to
base a further grouping of tlie material. Rave for the samples from Grand Narrows,

130 DEPARTMENT OF THE NAVAL SERVICE

which owing to the isohited locality of capture, situated so to speak, in the middle
of Cape Breton Island, must be considered apart, the samples may naturally be
divided, according to the age-analyses, into two groups, one embracing those from Main-
a-Dieu and North Sydney, the other those from West Ardoise and Nova Scotia.
The best sample in the northern group bears, as we have seen, a strong resemblance
to the single divergent sample from Newfoundland, while the southern samples again
exhibit features in common with a similarly exceptional sample from station 42, west
of Cape Breton island. In the northern group we find, presuming that summer growth
had not commenced in the beginning of June, the year-classes 1910, 1908, 1904 and
1903 as most numerously represented, in the southern, the 1911 year-class especially,
with, to a lesser degree, those of 1910 and 1908, predominating among the younger fish,
while in the case of the older ones, the uncertainty of the age-determination renders
it impossible to say definitely which year-classes are here the richest.

e. Comparison of the different areas.

In the foregoing, an attempt has been made to describe the age distribution in
the samples from the different areas, on the basis of a preliminary group arrangement.
And it was found that samples from dift'erent waters may dift'er altogether in point
of age composition, while those from one and the same locality exhibit a high degree
of similarity. Particularly striking is the likeness observable between most of the
samples from the Newfoundland coast, as also between those from Northumberland
strait. Ha\'ing now compared the separate samples and noted the points of
resemblance for the different areas, with due reference to such exceptions as occur,
it may finally be of interest to draw up as far as possible, a brief survey of the entire
area embraced, on the basis of the details furnished by analysis of the age distribution.

Fig. 38 shows the age distribution for a number of samples from different waters,
chosen from among the 1914 and 1915 samples. The principles upon which such
selection has been based will be found justified by the foregoing.

The figure shows, in its own way, how thoroughly unlike the samples from different
waters proved. Especially characteristic is the difference between the Newfoundland
samples, on the one hand, and those from the southern parts of the gulf on the other.
The samples from the Atlantic coast, however, also exhibit a marked dissimilarity to
the southern gulf samples and also to those from Newfoundland.

On comparing the two parts of the figure, we find, feature for feature,, a consider-
able likeness between them. Particularly marked is the resemblance between the
Newfoundland samples in the two years and those from Northumberland strait.

Having regard to the nature and quantity of the material, it must be admitted
that the analyses distinctly suggest the existence of several types of age composition in
the waters investigated, and it would also seem that in arranging the samples
according to age composition, we shall simultaneously have arranged them, roughly
speaking, according to locality of capture, i.e., that the samples from one and the
same locality exhibit similarity of age composition. That we can speak of such a
thing as a "type of age composition" is due to the fact that in a sample from a cer-
tain water, certain year-classes are found to be more niimerously represented than
the remainder, all year-classes present are not equally rich, and the curves for these
fluctuations thus acquire a typical appearance.

These differences in the samples from the various waters give rise to the sup-
position that the area investigated may include several races or tribes of herring,
each for the present with its own characteristic age composition. Judging from the
age curves, it might possibly he advisable in the investigations by means of growth
measurements, to start from the hypothesis here indicated by the arrangement of
fig. 38.

1. That the Newfoundland herring form a tribe apart, represented through-
out the present material in all samples, save the single exception.

CAXADIAX FISHERIES EXPEDITIOX, lOl'rlo

131

2. That the exception in question, the sample from St. George's Bay, and
the samples from Main-a-Dieu and North Sydney, represent another.

3. That the samples from Magdalen islands and Northumberland strait,
and off cape Gaspe, represent a third.

4. That the samples from West Ardoise and Nova Scotia, together with the
exceptional sample from the mouth of St. George's bay (station 42, west side of
Cape Breton island), represent a fourth.

1912 11 10 09 08 07 06 05 04 03 02 01
J«ar groups

1912 11 10 09 08 07 06 05 04 05 02 01

Fig. 38.

In the following pages, the observations as to growth of the herring will be sub-
jected to analysis, on the basis of the grouping above given. This should, however, as
in the case of the first rough arrangement, only be regarded as preliminary, and
intended but to serve present needs.

132 DEPARTMEyr OF THE J^AYAL SERVICE

XII.— GROWTH.

COMPARISON OF GROWTH IX SAMPLES OF SIMILAR AGE COMPOSITION.

A number of samples were taken from the material available, for further treat-
ment with regard to growth. In making this selection, several points were taken into
consideration. In the first place, it was desirable to include samples from as many
areas possible. In addition to which, it would naturally be interesting to investigate
in this respect such samples as might be said to occupy a peculiar ]X)sition in the
material, e.g., the one exceptional sample from Newfoundland. It was necessary,
moreover, to select those offering the best scale material, the quality of this being of
more importance in growth measurements than in age determinations. And finally,
it was recognized that the growth material should include, as far as possible, material
illustrative of the manner in which growth proceeds during the different seasons of the
year. With regard to this seasonal growth of the herring, there is but little inform-
ation to be gleaned from the present material, some facts may, however, be brought
to light by examination of the samples containing young fish.

The nature and quantity of the material will to a certain extent determine M'hat
problems may be taken up for consideration in these growth investigations: it is
undoubtedly best suited for a study of the growth in the different waters. This pro-
blem, then, will receive the greatest share of attention in the following examination,
and we shall, bearing in mind the results of the investigations as to age composition,
endeavour to arrive at a solution of the following questions: —

1. Are those samples which have been found to be of uniform character, as
regards age composition, likewise uniform or similar with respect to growth
of the individuals ; and

2. Are those samples or groups of the same, which differ in respect of age-
composition from the remainder,, likewise different from these in point of
individual growth?

The two questions taken as one may be formulated thus : Can the grouping accord-
ing to similarity and dissimilarity of age-composition, as drawn up in the foregoing
chapter, be further supported and rendered more distinct by consideration of the
growth of the fish?

In making comparisions of this nature, it would of course be an advantage to
have an opportunity of examining one or more year-classes common to all samples.
This will be done when we come to compare samples of like character as regards age-
composition ; having regard, however, to the great differences in this respect which
exist between the samples from the different waters, a very extensive mass of material,
with very large samples, would have been necessary in order to ensure that each sam-
ple contained a sufficient number of the particular year-classes. In the material as
it stands, we find, for instance, that a year-class which is well represented in tlie sam-
ples from Northumberland strait (the 1903 year-class) appears but very poorly so in
the Newfoundland samples. By proceeding according to this method, we should, in
comparing two samples from different localities in many, or possibly most cases, ac-
tually be comparing, pairs of values of which one only could be taken as accurate,
having been based on a great number of single observations, while the other would be
subject to a higher degree of error, being based on only a few observations. The error
in a difference between two values depends upon the separate errors in the two values
themselves, and will always be greater than the larger of these, with the method
referred to; therefore many comparisons would infallibly give unreliable results from
a statistical point of view. In the following comparisons, the greatest imiiortance

CAXADIAX FISTIKRIEH KXPEDITIOX, 19r',-l.j 133

is attached to the investigation of those year-classes which are best represented, and
for which we have the most accurate average figures, care being taken, however,
throughout to make sure that these good year-classes do not differ essentially with
regard to growth from the inferior ones. We thus avoid the necessity of making
lengtliy calculation for the inferior year-classes, and obtain at the same time some
idea as to how far the growth of the good year-classes is representative of the sample
(or samples, or water).

In the case of two equally strong year-classes the older will generally be employed,
as, in the case of the younger fish, a greater allowance will have to be made for the
effects of the dissociation previously mentioned. And in comparing young fish, there-
fore, the rule as to taking fish of equal age will have to be more strictly observed.

In making these comparisons, the average values (^4) only, have in some cases
been used. In cases requiring closer analysis, however, the standard errors (e) have

8
been calculated from the standard deviation (8) according to the formula e=\/n, where
n is the number of variates. In testing the difference between two averages, the stan-
dard error (d) of this difference calculated according to the formula d:=^e'^ + e\,
where e^ and e.^ are the respective standard errors of the two' averages. The standard
error of the difference compared with the difference itself (D) will then serve to indi-
cate what value should be attached to the difference; if the difference be great in pro-
portion to its error then it will in all probability be significant, i.e., not due to fluc-
tuations of sampling, and vice versa.

This calculation of the standard errors in the averages lias been carried out for
the growth dimensions t^ — t^; for t^ — ^k, the method employed was, save in such cases
where averages only were compared, as follows: When the analysis of and examination
of the averages for the remaining dimensions indicates similarity between a number
of samples, then one of these is selected, and the standard deviation for the dimen-
sions t^ — tj„ calculated for that sample. Presuming then that the standard deviations
for the other samples will be more or less equal to these, the standard errors for all
samples may be calculated from the standard deviations for the one. I have tested
this method, and convinced myself that the presumption is correct, and the consequent
simplification of the calculations thus justifiable.

In all mathematical comparisons, the calculated increment oi gro\\i:.h (0
has been employed, and not the calculated length (I), the former is, as far as I can see,
easier to deal with than the length ; for reasons of economy also it was found neces-
sary to restrict the work to the consideration of one of these dirnensions. In the fol-
lowing comparisons of the results, on the other hand, the calculated lengths have been
used, as being more immediately legible (the length of a herring can be seen, whereas
one can only form an idea as to its growth or increment).

1. Samples from Neivfoundland. — The age investigations led to the results that
all samples of grown fish from the coast of Newfoundland, with a single exception,
were characterized by the marked superiority of the lOO-t year-class. The single
exception (sample from St. Georges bay, jMay 27, 1915, exhibit remarkable likeness
to a sample from Korth Sydney, and will therefore be taken together with this.

Table 13 shows the averages for all increments of the year-class 1004, and the
standard errors of the averages for dimensions t, — t. all each single one of the nine
samples selected for growth measurements ; the lowest series in the table further shows
the total averages with corresponding standard errors, arrived at by taking all specimens
of the said yesr-class (in the nine samples) together as a single larger sample.

134

DEPARTMEXT OF THE yAVAL SERVICE

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CAXADIAX FI.'^HERIES EXPEDITIOX, 191.'rlo

135

By a study of this table, and comparison of the averages with due regard to their
errors, it will be seen that all the samples are very much alike. Among features
especially characteristic may be noted, that f, is on an average less than t.. and that
average values of less than 1 cm. are not reached until t„; further, that #, is more
than half as great as t^.

Some variation is, however, noticeable between the separate samples. It is found
that several of the largest samples exhibit tlie greatest difference, and it will there-
fore be desirable to inquire how far any degree of regularity can be discerned in the
variation, and whether it is so considerable as to suggest the probability of its being
due to other causes than fluctuations of sampling. In order to ascertain this, the
samples were first divided into three season -groups, one comprising the samples from
the spring of 1914, another those from the autumn of the same year, and a third those
from the spring of 1915. Table 14 shows the seasonal averages with corresponding
standard errors .

Table 14. — The samples from Newfoundland arranged according to season of capture.
Table showing averages and errors for growth dimensions t^-t^^ for year class
1904, all samples from each season being taken together.

Season.

1914, Spring . .

1914, Autumn.

1915, Spring..

Total . . .

No. of
individ.

238
240
128

606

6 20
6 08
600

6- 14

Oil
012
0 13

0 07

6- 99
6 98
6-99

6 98

0 07
008
0 09

0 05

5-42
5 39

5-51

5 43

006
006
0 08

00^

3 21
3 34
:V38

3 30

0-04
004

006

0 03

2-69
2-74

2-8.

274

0 04
005
006

0 03

219
200
2-16

2 11

1 54
137
154

1-47

108
106
114

1-08

0-83
0 92

0-89

0-88

Uo

0 64
o 75
0 74

0 71

It is not easy to discover any essential difference between the seasons here; ^i
falls a little, #2 shows no change, t?. is likewise unchanged, t^ and h rise slightly,
while i^, L and f^ are lowest in the autumn. All these differences are, however,
insignificant and lie within the limits allowable for fluctuations of sampling. Also
each seasonal group presents the same total view of the growth, as seen in each
separate sample or in all samples taken as one.

A somewhat similar result is arrived at by arranging the samples according to
locality, as in table 15.

Table 15. — Newfoundland samples arranged according to locality of capture. Table
showing averages for growth-dimensions t^ — /,„ for year class 1904, all samples
from each locality being taken together.

Locality.

No. of
individ.

ti

t2

t.

U

h

h

<7

U

h

ho

White Bay

Bonne Hay

Bay of Islands

93

95

179

104

5-62
6 35
6 09
6-92

6-98
715
704
701

5-69
5-58
5-48
5- 17

316
3 .32
3-41
3-21

2-80
272
2-84
2 57

2-48
2 12
213
1-96

1 80
1-47
1-51
1-31

1 13
109
1 11
1 06

0-66
0-88
0-91
0-97

0-55
072
0-76

St. George's Bay

0 73

In this case, the differences arc much more conspicuous. The growth dimension ^i
is lowest for White bay, and highest for St. George's bay. the reverse being the case
with t.^, while the dimensions t.^ — t^ are lowest for St. George's bay.

135

DEPARTMENT OF THE NAVAL SERVICE

7 GEORGE V, A. 1917

Judging from these averages, there might possibly be some slight difference
between the most northerly locality and that farthest to the south.

In order to test the value of the differences thus found between the various samples,
all possible differences between growth dimensions of the same character were first
ascertained, the nine samples giving thirty-six differences for each dimension, making
ISO in all for the five first dimensions.

For each of these differences (-0), the corresponding standard error (d) was then
calculated, and the fraction ^/d formed. This fraction, which expresses the difference
in units of its error may serve as a i^ind of indicator for the importance of the differ-
ence. Where the value of the fraction is small, there is but little probability that the
difference is due to other causes than accidental fluctuations, and vice versa, and in
particular, where its value exceeds certain limits, the probability becomes an empiric
certainty that the difference is not merely due to fluctuations of sampling.

Table 16 shows the manner in which the various values of the fraction ^/d
arrange themselves, firgt for each separate growth dimension, and finally for all
together. It will be noticed that in 91 of the 180 cases, the fraction is less than 1, in
154 less than 2, and in 171 less than 3. Only in 9 out of 180 cases is the fraction
over 3, i.e., in these cases the difference is more than three times as great as the
error. In the last column will be found figures showing the arrangement which
should have resulted had all samples been drawn from an entirely uniform stock and
subject only to fluctuations of sampling.

Table 16. — Showing distribution of values of — for all possible comparisons between
the nine samples from Newfoundland. (Year class 1904, t^ — t^).

Values of — between :
d

18

11

3

2

(■z-

<3-

ti-

<5-

16

14

5

1

Total.

Theoret.

0 and 1

1 „ 2

18

14

4

18

11

3

2

2

21

13

2

91

63

17

5

2

2

123
49

2 .. 3

3 ,, 4

8

4 1. 5

36

2
36

36

36

36

A comparison of tlu'.-;e theoretic values with the figures actually found, inclines

us to suppose that the nine cases where the value of — — exceeds three are probably

significant. And on examining these nine differences, it will be seen that they are
due to peculiarities in the sample from White Bay and in that from St. George's bay,
only in one instance is there a difference noted where neither of these samples is
included, i.e., between samples 7 and 8 for the growth-dimensions ^3. The small t^ and
the large t^ in the White Bay sample, with the large t^ the small t. and t.^ in that from
St. George's bay, give rise to the differences. It would thus seem that the dissimilarity
noticed in table 15, as between these two extreme samples, is significant. It is
impossible to say with certainty what importance should be attached to these differ-
ences, as several possible explanations may be given. As far as I can see, the most
reasonable supposition would seem to be that the sample from St. George's bay is not
quite " pure," i.e., that it consists of a majority of individuals, belonging to the same
growth type as that of the remaining samples, mixed up with a minority of another
type. From the nature of the dissimilarity noted, the growth of this second type
should be characterized by a large t^ and smaller i.^ t- t^ and t.,.

CA\ADIA\ risHERIE.^ E\I'EniTIU\, HH'i-to

137

On the whole, however, the samples are as nearly as possible equal in rejrard to
growth of the I'.HH year-class, as they were also found to be nearly equal in respect of
age composition.

The question now arises, whether the picture of growth presented by the 1904
year-class can be taken as representative for the remaining year-classes, and espe-
cially for that of 1903. In order to investigate this point, table IT has been drawn
up. showing the growth of the 1904 year class compared with that of the year classes
1903, 1905,, and 1906. as also with all older fish taken together and all younger ones
together.

Table 17. — Averag's for year class 1904 compared with those for other year-classes
in the samples from Newfoundland. Averages based upon all nine samples.

ear class.

19ll-li)06. .

1905 ..

1904. .

190.3. .
1902-1891...

No. of

individuals.

<,.

7 90

'3-

t.,.

'5-

1 31

<7-

<3-

'»•

<.o-

149

6-36

517

3 13

2 10

126

108

0-83

198

0 52

7 07

5 43

3 36

2 74

217

1 51

1 16

0 82

0-69

606

6 14

6 9b

5 43

3 30

2 74

2 11

1 47

108

0 88

0 71

45

6 67

7 47

5 17

3 24

2 54

2 00

1 45

114

0 91

0 75

84

6-88

7-81

4 72

3 47

2 55

1 69

1 37

109

0-86

0-72

'...

0 61
6-61

It will be seen from the table that the important features are common to the older
fish. The younger ones, and also, to some extent, the 190t) year-class, exhibit greater
deviation, a phenomenon also noted in the great majority of other herring samples
(ride p. 144.). It is impossible to say whether this dissimilarity in the younger tish, in
the present instance, is due to selective effect of the implements used, to the dissocia-
tion of year-classes, or to intermingling with fish of different growth. Probably each
of these features is to some extent responsible. It is at any rate evident that the 1904
year-class does not differ essentially, in point of growth, from the older tish. Also
that the small f,, at least, is probably characteristic for the herring taken on the
coast of Newfoundland as shown by table 18,. the growth of quite young fish from
western bay of Port au Port, August 16-17, 1915. The 1914 year-class, which is well
represented, and that of 1913, which furnished eleven specimens, show exactly similar
values for t^ and t„ to those of the old fish; the 1910 year-class is represented by only
two specimens, so that the figures for this are practically valueless, and are only
included as a matter of form.

T.^BLE 18. — Growth of small, immature herring caught by drift nets in West Bay of

Port au Port, Aug. 1915.

Year class

Age grouji.

No. of
individuals.

'i-

/,.

<3-

t^

<»•

ts-

11)14 .

2
3
6

101

11

2

« 36

6-80
7 45

7 26

760
6 55

4-24
7 45

4 20'

'2-80'

1913

1910

i 05

2. Samples from the Magdalen islands. — The 3903 year-class is the best common
year-class among the older fish in the Magdalen islands two samples, taken in spring
1914 and 1915. In the one sample, there were seventy-four of this year class, in the
other unfortunately but seventeen.

Table 19 shows the average values for the different increments (t) of this year-
class in the two samples. In the 1914 sample, t^ and t^ are less than in that from 1915,
whereas t. — f^ are greater. The remaining growth dimensions are practically alike in
both samples.

6551—13

138

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CA^AD]A^' FISH ERIE f< EXI'EDITWX, lOl'rlo

139

The standard errors of the averages for dimensions t^ — t^ have been calculated for
each sample separately and for both taken together. With the aid of these, it has
been possible to estimate the importance to be attached to the differences. It was
found that all the differences were between once and twice as large as the correspond-
ing error, and they can thus hardly be considered as noteworthy. And as the remain-
ing growth dimensions have also been seen to exhibit no difference, the two samples
should be regarded as equal, so far as concerns the growth of the 1903 year-class.
Characteristic features common to both samples are: i, is large, distinctly greater
that t„; average values of less than 1 cm. are reached as early as t.; and finally, t^ and
t„ are less than the following dimensions, t^^ and i^^.

If we now turn to the remaining year-classes in these samples, we find, as will
be seen from tabic 20, entirely analogous conditions, all year-classes exhibit an un-
mistakable likeness in respect of growth. There is the great ^i and the low values for
t; and onwards, and even so slight a detail as the fact that the last year's growth is
somewhat greater than that of the few years immediately preceding, is met with now
and again. As regards the 1904 year-class especially, which it would seem desirable
to compare with the same year-class in the samples from Xewfoundland, we find that
it forms no exception, save perhaps that the characteristic features are possibly even
more marked.

Table 20. — Averages for year class 1903 compared with those for other year classes in
the samples from Magdalen Islands.

Year class.

No. of
individuals.

^i

ti

tz

U

^5

h

^7

^8

. tt

<10

<ii

tl2

1910

21

11 2

8'8

4-7

2-6

1909

16
26
26

11
10
10

9
3

1

8
9
9

4
.5
3

3 9

4 3
3-9

28
2-4
2 6

8
8
7

3

4

1908

19('7

10

190t;

22
31
32

11
11
10

2
3

8

8

8

7

7
6
5

4 3
3-9
4 2

2 0
2 3

2-7

3
3
4

0
0
0

10
0-8
OS

0-9
0 9
0-7

1905

0-8
08

6-8

1904

1903

91

10

3

7

3

4 6

2-9

5

0

0-8

0 7

0-7

0-7

0-8

0-8

1902

9

11

3

8

C

40

2-4

4

1

0-7

(••7

0 6

0-6

0-5

0-5

1901

6

11

2

8

9

39

2 5

4

1

0-7

0-6

0 5

0 4

04

0-4

1900

13

10

R

1-

q

4 2

2-8

1

0 9

0-7

0 5

0-5

0-4

OS

We find then, for these two samples also, that the growth of the fish is alike in
both; and that 1903 year-class may be taken as representative for the remainder, at
any rate for the older fish.

3. Samples from Nortlnimherland Strait. — In the five samples of grown fish from
this area, 1903 is the best common year-class among the older fish, and 1907 among
those of medium age. These two year-classes were therefore subjected to closer
examination. Tables 21 and 22 show the averages and standard errors for these year-
classes, in each of the five samples.

6551—13*

140

DEPARTMENT OF THE NAVAL SERVICE

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CANADIAN FISIHERIEfi EXPEDITION, lOUf-lS

141

Table 22. — Showing averages for growth dimensions /, — f^ for the year class 1907 in five
samples from Northumberland Strait, 1914-1915. At the foot, total averages and
their standard errors.

Locali'y and Date.

Northd. Strait, May 1914 34

Baie Verte, May 11, 1914 17

Pictou Harbour, May S, 191.5 17

Richibucto, May 19, 1915 2fi

Bale Verte, May 22, 1915 16

Averagfs for the two samples from 1914 together.

Standard errors •< i< u 1914 n

Average><for the three samples from 1915 .■

Standard errors i. „ •■ 1915 h

No. of
individ-
uals.

Total averages.

10 4;

8-70

3 99

2 49

2 54
2 35
2 44
2 74
2 50
OO'
2 50
0 0<

2 50

•57
•56

69
•57

56
■57

Of;

60
04

1 43
142
1 .30
140
1 39
1 43

1 37

I 59

1-39

t

1

04

1

01

1

15

1

20

1

IS

1

(»3

1

18

1

11

114
124
118

1 19

119

It will be seen from the tables that there is certainly a considerable degree of
similarity between all the samples ; there are, however, also differences which seem,
despite the small number of specimens, to be by no means negligible. Thus, sample
11 differs in its small /, in the 1903 year-class, and Northd. Strait sample in the
same manner as regards the 1907 year-class. In order to test the value of these
deviations, the method adopted in the case of the Newfoundland samples was also
applied here, all possible differences (D) between samples two and two were taken
(for growth dimensions of like character) and the corresponding standard errors of

the differences (d) formed; and finally, the fraction 7 obtained. It was then found.

as will be seen from table 23 that the value of

in one case out of fifty, is

greater than three. This single difference, of considerable magnitude in proportion
to its error, occurs between samples and for the growth dimension /i. Save for this
single instance, all the differences are relatively small, being here, as in the New-
foundland samples, in the majority of cases less than twice their error.

Table 23. — Showing distribution of values of -^ for all possible comparisons between
the five samples from Northumberland Strait. (Year class 1903, t^ — ^5).

Vahus

of —between
(1

ti

h

t3

U

'5

3
6

1

10

Total.

0 and 1

1 and 2

2 and 3

More than P>. .

5
4

1
0

10

7
2

1

4
6

0
4

1

24

22

1

10

10

10

50

As the remaining growth dimensions likewise show considerable similarity between
the various samples, we must conclude that there is no essential difference, as far as
the good year-classes are coiaicerned. With regard to the remainder, these show,
as will l>e seen from table 24, considerable resemblance to the two more closely
examined. These last may therefore be taken as representative of the samples when
comi>aring them with samples from other waters. This will accordingly be done,
the 1903 year-class being used in cases where it is desirable to have older fish, and
1907 where younger are i)referable for purposes of comparison.

142

DEPARTMENT OF THE NATAL 8ERYICE

Table 24. — Averages for year classes 1903 and 1907 compared with those for other
year classes in the five samples from Northumberland Strait.

Year elates.

1011
1910
1909
1908
19!)7
1900
1905
1904
1903
1902

Number

of

individual.s.

5
43
51
23

110
25
35
52

173
13

/l

h

12-6

8-9

12-8

7'7

12 9

7 3

11-3

8-4

10-5

8 8

111

7-6

12 3

6-9

10-4

6-7

10 2

6-5

11-2

7 0

^6

^6

t^

h

U

<10

tn

tl2

8

3

1-8

9

1-8

6

6

1-7

3

1-4

5

1-6

4

11

1-2

6

1-5

1

10

10

11

G

13

0

0 8

0-9

0-8

0-9

0

1-6

1

0-9

0-9

0-8

0-8

0-8

0

10

1

0-8

0-7

0-7

0-7

0-8

0-8

8

1-6

10

0-8

0 6

0-5

0-5

0-6

0-6

hi

0-6

If we are to characterize the growth of the individuals in these samples, w^e can
only repeat what has been said in the case of those from the Magdalen islands; the
similarity existing between these two waters, in respect of age composition, is sup-
plemented by the resemblance noticeable in the growth of the fish. We shall later on
examine the question as to whether there is any essential difference between these
waters as regards growth.

It may not be out of place here to mention the samples containing very young
fish. Some of these are from the waters about Prince Edward Island and the Gaspe
coast, others from the neighbourhood of Souris and cape George. Table 25 shows
the average value for these samples.

Table 25. — Showing averages for growth dimensions t^ — t^ for young herring in the
waters around Prince Edward Island. Values with an asterisk are incomplete.

Locality and date.

Station 33, 48" 13' N.. 63= 58' \V., July 5-C, 1915 -

Station 3.5, 46" 48' N., 64" 32 W., July 7, 1915

Souris, July 14, 1915 -{

Station 53, 45" 46' N., 62" 23' W., July 30-31, 1915... '

Year

Number

of

li

h

^3

U

group.

individuals.

1913

31

10-6

7-9

1-4*

1912

6

7

9

7-9

5-5

10*

1913

47

10

2

7 1

1-8*

1913

14

11

3

8-2

10*

1912

19

10

2

8 8

4-9

10*

1914

12

11

1

3 9*

1912

7

11

5

80

4-5

1-9*

It should be borne in mind that the last growth dimension in most of these sam-
ples is incomplete, and cannot therefore be compared with the same in the older fish.
The table shows that these young fish also are characterised; by a high value for t^,
exactly the reverse of what was the case with the young fish from Port au Port (taken,
it is important to note, with the same set of gear as the present samples from the
Gaspe coast). As regards the differences apparent between the different samples, and
between the different year-classes, it should be remembered that both dissociation of
year-classes and net-selection must doubtless have had some effect. Making allowance
for these considerations, the resemblance between the samples is marked.

CA^fADIAX FLSHERIES EXPEDITIOy, lOl-'f-lo

143

In view of the great similarity between the samples of grown fish from Magdalen
islands and Northumberland strait, it would be of little use to go into the question
as to how far the present samples of young fish more resemble those from the former
or those from the latter waters ; they may fairly be said to exhibit a considerable like-
ness to both.

4. Samples from North Sydney compared with the highly exceptional sample from
St. Georges hay, Newfoundland. — As repeatedly mentioned already, one of the sam-
ples from the Newfoundland coast differed greatly from all the rest in. point of age-
composition, while exhibiting, on the other hand, a very strong resemblance to a sam
pie taken at the same time from Xorth Sydney. It will now be well to compare these
two samples from the point of view of individual growth.

There is no age group which is particularly well represented in these two sam-
ples, group 7 (=year-class 1908 if, as would seem to be the case, new Summer growth
had not commenced at time of capture) is the best, and comprises 23 specimens in
the North Sydney sample, and 25 in the other. After these, come age groups 11 and
12 (presumably corresponding to year-classes 1904 and 1903). In the following com-
parative tables, where the errors of averages have been called into requisition, age-
gi'oup 7 is taken separately, groups 11 and 12 being combined into a single group, in
order to furnish a reasonable number.

Table 26 shows averages for group 7 in the two samples, in addition to which, the

standard errors of the averages and the values of the fraction -^ are also noted.
Table 26. — Showing averages for growth dimensions t^-t. for the divergent sample
from St. Georges Bay and for sample from North Sydney. (Year class 1908,

presumably). At foot the differences and values of fraction -j-.

Sample.

N. Sydney

St. George's Bay .
Difference (D). . .

D

d

10-40

10-28

012

0-29

9 43
0 22

0-51

41G
4 28
012

0 52

2-64
2-79
0-15

0-79

1-79
1-89
010

0 83

It will be noticed that this age group exhibits the most perfect uniformity as
regards growth, and in no single instance, among those investigated, does th*» diffe-
rence between two averages equal the magnitude of their errors.

Very similar results are arrived at in the case of groups 11 and 12. Table 27
shows these two groups compared in the same manner as with group 7.

Table 27. — Showing averages for grovrth dimensions /, — t^ for the divergent sample
from St. George's Bay, and for sample from North Sydney. (Year class 1903 and

1904 presumably). At foot the differences and values of fraction — r .

Sample.

h

h

tz

ti

h

ts

I
ti

i

10-90

818

4-32

2-41

1-Hl

1 14

0 77

10-93

8-09

4-36

2-65

1-58

1 20

0-94

0 03

0-09

004

0 24

003

0 06

017

0-07

0-26

0 15

1-41

0-19

0 46

2 12

N. Sydney

St. George's Bay.

Difference (D). . .

D

0 78
0-82
004

0-57

144

DEPARTMENT OF THE NATAL SERVICE

Here again the resemblance between the two samples is striking, while the diffe-
rences are insignificant. Only in two instances does the value of the fraction ~j"

exceed 1, which differences, however, also lie well within the limits for fluctuations of
sampling.

Table 28 shows these two samples compared with regard to the remaining age
groups.

Table 28. — Comparison of the divergent sample from St. George's Bay with the sample
from North Sydney by help of averages for all year-classes presenting a reasonable
number of specimens.

Year group.

1911

1910

1909

1908

1907

190G

1905

1904

1903

Sample.

i St. George's Bay
I North Sydney . . .
( St. George'.s Bay
t North Sydney . . .
f St. George's Bay.
I North Sydney . .
( St. George's tiay
\ North Sydney . .
fSt. George's Bay
\ North Sydney .
t St. George's Bay
( North Sydney . . .
I St. George's Bay
\ North Sydney. . .
j St. (xeorge's Bay
t North Sydney
/St. (Teorge's Bay
\ North Sydney. . .

No. of

dividiials.

ti

t2

tz

^4

h

^6

ti

^8

U

tlO

tn

4

11-7

10-6

4-8

3 2

5

11

6

8 2

5 2

3

0

13

12

7

8

4

4 6

2

5

8

12

13

0

8

0

4-5

2

G

G

9

12

1

8

.5

41

2

9

/

1-4

6

11

0

9

1

4-2

3

0

G

1-4

23

10

;.)

9

4

4 3

2

8

9

1-3

1-2

2.5

10

4

9

6

4 2

2

G

8

1-3

1-2

9

11

3

8

9

4 4

2

3

6

14

11

11

9

11

1

8

8

3 4

2

5

7

1-6

11

10

7

10

9

8

.5

4 4

2

0

1

6

11

1-3

0-9

0

8

8

11

9

8

.5

4 3

2

3

4

11

11

0-8

0

8

6

12

1

7-9

3-7

2

0

4

0-9

10

0 8

0

8

0-7

1

n

4

8 8

5 4

2

7

8

1-3

0-8

07

0

6

0-5

17

10

7

8-(i

4-6

2

5

7

13

0-9

0-8

0

9

08

0-7

17

11

1

8-3

4 3

2

2

1

1 1

Oh

0-8

0

9

0-8

0-7

12

11

3

8-2

4(1

•)

8

A

11

0-9

0-8

0

8

0-7

0-7

12

10

G

8

0

4-4

2

6

5

11

0-8

0-7

0

7

0 7

0-7

tn

0-5
0 6

This table strongly confirms the impression furnished by the previous ones, of
similarity between the two samples. We may safely say that the resemblance is no
less marked as regards growth of the individuals than it was seen to be in respect of
age composition.

Comparison of samples from West Ardoise, Locl-eport, and west of Port Hood
(station Jt2).

Only young fish of the 1911 year-class are here numerous in all four samples, the
calculations as to errors of averages and comparison, on the basis of the same, have
therefore been restricted to this group.

Table 29 shows the averages for this year-class together with the corresponding
standard errors.

Table 29. — Averages (A) and standard errors (e) for the year-class 1911 in three
samples from the Atlantic coast and one from west of Port Hood.

Locality and Date.

W. Ardoise, .July, 1914

August, 191 4 .
Lockeport, November, 1''14
W. of r . Hood, July, 19 1 5

No. of
individuals.

G3

25
57

8fi

12-44
12 99
12 14
12.68

0-21
0-34
0-24
0-21

8-12
872
7-76
S-44

Oil
0-28
0 14
0 12

482
443

4 85

5 12

014
0-20
016
010

2 07*
1 45*
2-20*

3 38

0 06
0 09
007
0 09

CANADIAN FIh;n FRIES EXPEDITIOW J9l.'rl5

145

Only the dimensions t^ — t^ will be of interest in this connection, as t^ is incomplete
in the samples from 1914.

A test calculation of the fractioii -j- gave three ditferences of eighteen, which
were over three times as great as the corresponding standard errors. It was the
sample from Lockeport which differed in respect of ^ from the West Ardoise (August)
sample and from station 42, while station 42 again differed in respect of ^3 from the
West Ardoise (August) sample. In the remaining fifteen cases, the differences were
less than three times their standard error,

5 differences being less than once,
11 " " " twice,

15 " " '' three times,

18 " " '' four times,

the corresponding error.

The similarity between the various samples is thus on the whole good, albeit less
so that in the cases previously dealt with. It should, however, be borne in mind that
the comparisons in this case are made with young fish, where the dissociation of year-
classes will be more likely to make itself felt.

Of other year-classes which might be selected for comparison between one sample
and another, that of 1910 is the best; the number of specimens is here, howe\er, so
small, that it would not be worth while to make calculations of the standard errors.
Table 30 shows the averages for this year-class.

Table 30. — Averages for the year class 1910 in the four samples mentioned in

table 29.

Locality and Date.

\V. Ardoise, July, 1914

August, 1!I14
Lockefwrt, Xovembei-, 1!»14
W. of Pt. Hood, July, 1«J15

Ivo. of

In-
divid.

12
18

28

12 2G

12-30

9 82

11 94

8 Ofi
7-87
8-8S
785

u

h

2-69

I 41*

2 ■ S9

1 14*

2-59

1 44*

2 -95

2 01

Save for the incomplete dimension t^ these samples agree, well enough, as will be
seen, always bearing in mind the small number of individuals dealt with. Only the
sample from Lockeport differs in respect of the small t^. The interesting sample from
station 42 (west of Port Hood) does not appear to differ in any essential degree from
the remaining samples.

Finally, table 31 shows comparison for the 1908 year-class.

Table 31. — Averages for the year class 1908 in the four samples mentioned in table 29.

Localitj- and Date.

No. of
individ.

ti

h

^3

^4

h

^6

l7

VV. Ardoise, July, 1914

August. 1914

Locke))ort. November, 1914

W. of Pt. Hood, July 1915

7

7
0

10

UG

10 6

11 3

11 6

b 3
77
71
7 G

4-5

4 6

5 3
51

.S 2
3 8
3-8
3 5

20
2 6

18

14
1 6
10
16

0 9*
0-7*
0 6*
12

Taking into consideration the extremely small number of observations in each
sample, the resemblance here again is noteworthy. With regard to this year class also,
the sample from station 42 differs in no way from the remainder.

146 DEPANTMEXr OF THE NATAL SERVICE

All things considered, these samples must be said to be fairly uniform with regard
to growth, and even with the points of difference noted, each separate sample yet
presents a type of growth unlike those hitherto observed, and characterized by the
high values of all growth dimensions investigated. The same impression is obtained
if we collect the really old fish from all samples and consider their growth as it will
appear in some tables subsequently.

The type of growth may be characterized as approaching, with regard to t^ the
samples from the southern part of the gulf, while as regards the remaining dimensions,
it more resembles the Newfoundland samples. This will be further discussed in the
following section.

5, Samples differing in point of age composition. — It will be seen from the fore-
going, that samples resembling one another in point of age composition likewise
exhibit resemblance as regards growth. This double likeness is very marked between
all samples from Newfoundland save for the single exception, the sample from St.
George's bay; strikingly so between this and the one from North Sydney; good between
the two from the Magdalen islands and the five from Northumberland strait; and still
good, albeit less conspicuous, between the samples from West Ardoise, Lockeport, and
west of Port Hood.

Hitherto, our comparisons have been made between samples which, from their
age composition, appeared at first sight as belonging to the same group or tribe, or
whatever it may be termed. We may now proceed to make comparisons between the
different groups of samples into which the material was provisionally divided.

The object of this is twofold. In the first place, to carry the analysis of the
growth observations a step further, and endeavour to ascertain whether any of the
groups set up in the preliminary arrangement can be taken together. This possibility
will more especially require investigation in the case of the samples from Magdalen
islands and Northumberland strait, the two groups which bear an evident likeness
one to the other in point of age composition, and growth. With the sample from
North Sydney also (and its companion from St. George's bay) it will be desirable to
look into the question of how far combination should be made, for instance, with the
sample from West Ardoise and Lockeport, i.e., whether the former may be taken as
representing the older fish in the group from which are derived those younger spe-
cimens composing the latter; the latter having but recently attained maturity, and
having not yet attached themselves to the shoals of the elders. And in the second
place, it will be necessary to examine the various groups of samples together, and thus,
by pointing out the differences existing in point of growth, to show up more clearly
the resemblances already found. Further, to describe the types of growth as far as
can be done upon the basis of the resvilts obtained from the previous analysis.

In this further analysis, which will to a certain extent take the form of an analysis
of growth in the different waters, we shall first of all make comparison of the total
averages for growth dimensions as calculated on the basis of several similar samples,
and in addition,, examine the differences between pairs of single samples, e^ch from its
own groups of similar material. This latter method of comparison is more especially
intended to show the manner in which examinations of single samples here leads to
the same results as obtained by taking several together. A demonstration for instance,
of the marked and uniform differences between any of the nine Newfoundland samples
and any other, will, by a further test, afford further justification for our regarding
these nine samples as representing a distinct growth type. And in a similar manner,
the correctness of the remaining group divisions will be tested.

For the sake of convenience, the nine similar samples from Newfoundland will
first be compared with the remainder, then those from the Magdalen islands will be
taken, and in like manner compared with the rest, and so on. The comparisons will
be illustrated by means of curves for growth and increment.

The nine similar samples from Newfoundland will now be compared with the
remaining niatorial.

r.jvi/>/i\ FisiniRii.s i:\iT.niTioy\ loi'rio

147

6. Comparison vith the samples from Magdalen Islands. — The following table 32
shows total averafTt's for the nine samples from Xewfoundlaiid, taken together; for the
two Magdalen Islands samples taken together; the differences between gp>\vth
dimensions of the same character with the corresponding standard error, and the

fraction -j-.

a

Tabf^e 32. — Growth of Newfoundland herring compared with that of herring from
Magdalen Islands by help of total averages for year-class 1904 and 1903 res-
pectively.

.\cea of sanijiles

Newfoundland

Magdalen Tsland.-s . .

Difference ( D)

D _„

Standard error of difference — r
ti

h

h

^3

U

h

ti

ti

h

h

6 14

6-98

f>iB

3-30

2 74

2 11

1 47

108

0-88

10-25

7-26

4-62

2-85

lo2

104

0-78

0-6G

0-66

4 11

0-28

0-81

0 45

1-22

107

0 69

0 42

0 22

22 8

1-9

7 4

6 4

20 3

26 8

17 3

210

11 0

071
0 73
002

10

It will be noticed that all differences except /2 ' and tio must be regarded a3
significant, being greater than seven times their error. Judging from the values of

the fraction ;y the growth dimensions ^i, t-,, tr,, t-, and ^s would seem to differ most

in the two sets of samples, h being greatest in the sample from the Magdalen islands,
the remaining dimensions being the smallest. On comparing each of the tw^^ samples
from Magdalen islands with each of the nine samples from Xewfoinidland, exactly
similar results were obtained, even in the case of the 1915 sample from the former
locality, where the number of specimens was so very small (seventeen). This will be

seen from the following table, showing the value of the fraction -^ for each growth

dimension up to t.^, all values exceeding four, however, being for the sake of conveni-
ence placed in one group.

Table 33. — Showing distribution of the values of -, arising by comparison of either

a

of the samples from Magdalen Islands with either of the samples from Xew-

foundland.

Value of — between.
d

h

■""'l8
18

<2

h

U

h

h

U

U

Total.

0 and 1

1 .. 2

10
3
5

18

10
3

2 .. 3

1

4

13

18

2

10
6

18

8

3 .. 4

14

4 and more.

18
18

18.
18

18
18

18

18

109

144

It will be seen that save for ^, all the growth dimensions exhibit distinct differ-
ences between the Newfoundland samples on the one hand, and those from the Mag-
dalen islands on the other; most of the differences, moreover, are of a very consider-
able magnitude in pro{X)rtion to their errors, and the impression produced by this

148

DEPARTMENT OF THE NATAL SERVICE

table is thus totally different from that given by table IG (p. 136), showing the inter-
nal differences exhibited by the Newfoundland samples when compared one with
another.

Comparison with the sample from Northumberland strait. Table 34 corresponds
to table 32 and shows the total averages of the Newfoundland samples compared with
total averages for the samples from Northumberland strait.

Table 34. — Growth of Newfoundland herring compared with that of herring from
Northumberland Strait by help of total averages for year-classes 1904 and 1903
respectively.

Area of sami)!es.

ti

6 14

10 18

4 04

311

ti

t3

5-4;s

4 94

0-49

6-1

t,

3-3(1
2-98
0 32

5 3

2-74
1-58
1-10

23 2

^6

2 11
1 18
1 03

46-9

ti

1-47
0 81
0 66

30 0

t<<

1-08
0-72
0-36

25-7

t

0-88
0-70
0 18

8-2

<10

Newfoundland

Northumberland strait

Difference (D)

698
6-45
0 53

5- J

0-71
0-72
0 01

D

_ D

0-7

Standard error of difference

The table here shows that the Newfoundland samples, when compared with those
from Northumberland strait, differ from these in very much the same way as they
were seen to do from the Magdalen islands samples, the difference for t., however, is
greater, and must be considered as significant. In view of the great differences appa-
rent, I have not considered it necessary to show comparison between the separate sam-
ples; such a table would, roughly speaking, be merely a repetition of table 33.

7, Comparison with exceptional sample from St. George's Bay. — Table 35 shows
the total averages of the nine similar samples from Newfoundland compared with the
corresponding averages for the exceptional sample, the 1904 and 1903 classes being
taken together in the latter.

Table 35. — Growth of Newfoundland herring compared with that of the herrings of
the divergent sample from St. George's Bay by help of total averages for year-
class 1904, in Newfoundland samples, and those for year-classes 1904-1903 in
the divergent sample.

Sample.

1

h

^3

U

ti,

<6

t7

«8

Newfoundland (nine
St. George's Bay. . .
Difference (D)

samples) . . .

6-14

10 -9.^

4-79

6-98
8 09
1 11

5-43
4-36

107

3-30
2-65
0-65

2-74
1-58
116

2-11
1-20
0 91

1-47
0 94
0 53

1-08
0 82
0-20

D

d

14 5

4-5

5-6

5-9

14-5

10 1

8-7

5 2

The table shows the great differences between the exceptional sample and the
remaining ones from Newfoundland; these differences are indeed so marked as to be
distinctly apparent even when making comparison with the few (seventeen) specimens
of the 1904 year-class contained in the former sample as shown in table 36.

CAXADI.W FISHERIES EXPEDITIOS, 191 ',-15

149

Table 36. — Growth of Newfoundland herring compared with that of the herrings in
the divergent sample from St. George's Bay, by help of averages for the year-
class 1904.

Sample.

Newfoundland (nine samples)

St. George's Bay

Difference (D) .'

D

d

ti

<2

h

U

h

te

<7

6 14

10-68

4 54

G 96
806
1 08

5 13
4 62
0-81

3 3f)

2 50

080

2 74
1-62
1 12

2 11
1 25
0-86

1-47
0 95
0 52

9 1

33

3 2

2 7

14 0

7-2

6 5

1 08
0 84
0 24

3 4

There can thus be no doubt that the exceptional sample differs strougly both with
regard to age composition and growth, from the remaining Newfoundland samples.
The difference in growth is again of a similar character to that noted between the
Newfoundland samples and those from the Magdalen islands, the greatest differences
are found in the growth dimensions ^,, t., t^ and t.. Here, likewise, t^ is greater in
the exceptional sample, while the other dimensions are smaller.

Table 37 shows the exceptional sample compared with each of the remaining New-
foundland samjiles separately; the order of magnitude of the fraction -, being given
for the differences between the five first growth dimensions.

D

Table 37. — Distribution of values of fraction ~ arising by comparison between the

a

divergent sample from St. George's Bay and each of the nine other samples

from Newfoundland.

Value of fraction — between :
a

U

h

<,

tA

h

Total.

0 and 1

1 „ 2

1
I
2
5

1

2 .. 3

1

3 M 4

4 „ 16.. ..

9

2
t

1

8

■'"9"

5
38

It will be seen that the exceptional sample differs strongly from each one of the
remainder.

8. Comparison with the sample from North Sydney. — In view of the great resem-
blance which exists between the sample from North Sydney and the exceptional sam-
ple from St. George's bay, it might appear sui>ertluous to make any further comparison
between the former and the Newfoundland samples. For the sake of completeness,
however, this has been done in table 3S, and we find that the Newfoundland samples
differ from this sample exactly as they were seen to do from the exceptional sample
from St. George's bay.

150

DEPARTMENT OF THE yATAL SERVICE

Table 38. — Growth of Newfoundland herring compared with that of the herring in
the sample from North Sydney by help of total averages for year-class 1904 in
the case of Newfoundland herring, averages for the year-classes 1904 and 1903
taken together in the other case.

Sample.

ti

ti

t3

ti

ti

ti

ti

^8

bl4

10-90

4-76

6 98
8-18
1-20

5-43
4-32
111

3-30
2-41

0-89

2-74
1-61
1-13

2 11
1 14
0-97

1-47
0-77

0-70

108

North Sydney . .

Difference (D)

0-78
0-30

D

D

14 0

4-8

iJ-2

6-8

8-1

10-8

14 0

Standard error of difference ~

60

9. Comparison with old fish from West Ardoise, West of Port Hood, and Locke-
port. — In order to procure material for comparison of the Newfoundland herring with
fish of old age from the Atlantic coast, it was necessary to collect older specimens
from the different samples. Taking all those of the 1904 and 1903 year-classes toge-
ther we have a total of thirty-four fish, one of which is from the sample taken at sta-
tion 42, west of Port Hood. Averages and standard errors for these thirty-four speci-
mens have been calculated, and comparison made accordingly, with the results shown
in table 39.

Table 39.- — Growth of Ne^^'foundland herring (year-class 1904) compared with that of
herring from Nova Scotia (year-class 1904 and 1903 together).

Locality.

Newfoundland
Nova Scotia
Difference fD)

d

0 14

11-24

510

15-5

0-99
7-76
0-77

3-1

5-43
4-97
0-46

2 1

3 30
304
0-26

2-74
205
0-69

211
1 36
0-75

12-5

1-47

in

0-.36

7-2

108
0-87
0-21

5-2

There is here, as will be seen, a very marked difference in growth between the
Newfoundland fish and those from the southern portions of the Canadian Atlantic
coast. The differences here again are most distinctly apparent in the growth dimen-
sions /j and ^5 — t^ and resemble those found in the case of the sample from North
Sydney, t^ and t^ being greatest in the fish from the Atlantic coast, the remaining
dimensions less.

10. Graphical illustratic'ns of the results obtained. — Figs. 40 and 41 show, in gra-
phical form, the results of comparison between the growth of the Newfoundland
herring and the growth of those in the remaining samples. In order to avoid a figure
complicated with too many curves, we have here shown, in fig. 40, the growth of the
Newfoundland herring compared with that of those in the samples from the gulf of
St. Lawrence (Magdalen islands and Northumberland strait) and in fig. 41 with that
of the Atlantic fish (North Sydney and southern samples). The upper portion of
each figure presents in graphical form the data already utilized, i.e., the average
calculated increments, while the lower portion showing ordinary growth curves, gives
the actufil length of the herring at the time of the formation of each winter ring on
the scales.

ti tz ^i -t^ . ^S tt> '^7 ^6 ^9 ^}

fo ''//'

>^

^z t, ^

(. i

s 4 ^

7 ta t

9 -t

Si» r»

cm.

iO

\

■

J

1

ncrement

MewFoundland
\iw\h Svdiie>

5,

^

<

\

1

/

>

Nova Scotia

4

9

>

^^^

-

^^

"•^^c

-^

^^===:

=?=•

^-^=^

»^^

'jri.

_^ ^

,..'"

—

^;-:::

30

-

^^ rf

^,^-

20

-

t

/

/

/

Lengths.

/

/

New found land

1

■

/ ,

/

Nor^h Sydney

lA

J

' /

Nova Scoha

I

1

/

5

f

< i 4

'f ■4" 4 ^ <^ ^ Vtf ^/

Fig. 41.

CAXAfnw Fisin:i{n:>i ExrEDniox, lOi'rJS

153

The curves for increment need no further comment, the differences hetween the
Newfoundland samples and the remainder having been sutftciently indicated in the
foregoing. The length curves show how the Xewfoundland herring, starting modestly
enough, ends, owing to the favourable growth of the later years, with an average length
greater even than that of the fish from the Magdalen islands and Xorthumberland
strait (fig. 40). Fig. 41 shows that the somewhat slower growth of the Newfoundland
fish during the first two years enables the Atlantic herring, and, to a lesser degree, also
those from North Sydney, to maintain a part of the distance gained during the first
years, albeit the differences become more and more reduced with increasing age.

11. Samples from Magdalen islands compared with the remainder. — The samples
from Magdalen islands have already been compared with those from Newfoundland,
and were found to differ greatly from these with regard to growth. It now remains to
compare them with the samples from Northumberland strait. North Sydney (includ-
ing the exceptional sample from St. George's bay) and with the Atlantic herring.

Table 40 shows the samples from ^lagdalen islands compared with those from
Northumberland strait, by means of total averages for the 1903 year-class in both
waters. The table is arranged in exactly the same manner as table 32.

Table 40. — Growth of herring from Magdalen Islands and Northumberland Strait
compared by help of total averages for the year-class 1903.

Locality.

Magdalf n Islands . . .
Xiirthnmberland Strait

Difference (D)

D

d

10-

10-181
OO7I

7 2fi
6 4.^
081

0.351 4-77

4 62
4 94
0-32

2-67

^

h

h

ti

h-

U

2-85

1 52

1 04

0:8

0 60

0 66

2 9-

1-58

108

0 81

0 72

0 70

0 13

006

0 04

0 0.3

006

004

1-62

100

1 33

100

3 00

1-33

tia

0 73
0 72
0 01

0-50

It will be seen that the growth dimension t„ is the only one exhibiting a difference
which can really be called significant. Possibly 1 and t^ also differ; otherwise the
differences are unimportant in proportion to their errors. In order to test the one
really serious difference, the two samples from the Magdalen islands were compared
with each of the five from Northumberland strait, as regards the first five growth'

dimensions. Table 41 shows the values of — here found.

a

Table 41. — Distribution of values of fraction -j- arising by comparison between each

of the samples from Magdalen Islands and Northumberland Strait (year-class
1903).

Values of fraction — between :

ti

t;

h

ti

h

Total .

0 and 1

4

5

1

3
1
4
2

5
2
3

4
5

1

16

1 ., 2

2 M 3.

1
4
3
2

14
13

3 „ 4 ....

5

More than 4

2

Sum

10

0

10

10

10

50

It will be noticed that the differences for t„ are greater than three times their
error in five out o? ten cases and exceed twice the error in nine, whence it would seem
6.5.51— n

154

DEPARTMENT OF THE ?\ATAL SERVICE

likely that the figures express a real difference between the two sets of samples. The
difference cannot, however, be called great, as presented in these comparisons.

Comparison with the sample from North Sydney, and with the exceptional sample
from St. Georges bay. Table 42 shows the total averages for the samples from Mag-
dalen islands compared with the averages for the above-mentioned samples, which, in
contrast to those from the Northumberland strait, both exhibit a greater t^ than the
Magdalen islands samples. Otherwise, there is a not inconsiderable degree of similarity
in regard to growth.

Table 42. — Growth of herring from Magdalen Islands and North Sydney and St.
Georges Bay divergent sample compared. (Year-classes 1903 for Magdalen
Island, 1903 + 1904 for the other localities compared.)

Locality.

tl ti

h

. U

h

h

U

078
0-94
016

2.3

0-77
001

0-2

h

Magdalen Islands

10 25
10 93

0 68

19

10-90
0 65

1-8

7-26
809
0-83

3 0

818
0 92

3-3

4-62
4-36
0 26

1-2

4-32
0-30

1-4

2-85
2-65
0 20

15

2-41
0-44

3 1

1-.52
1-58
0 06

0-7

1-61
0 09

0-6

104
1-20
C16

1-8

114
0 10

11

0 66

0-82

0.16

D

( D)
(d)

"(W

01)

3-2

Standard error of difference =

North Sydney

Difference = (Dj

D

0-78
012

2-4

Standard error of difference. =

The comparison with the older fish from the Atlantic coast is interesting. Table
43 shows the samples from ]\Iagdalen islands compared with the thirty-four specimens
of the 1904-03 year-classes representing the samples from West Ardoise and Lockeport.

Table 43. — Growth of herring from Magdalen Islands (year-class 1903) and Nova
Scotia herring (year-class 1903 + 1904).

Locality.

t\

^2

iz

?4

U

h

t-,

1%

Magdalen Islands

Nova Scotii)

Difference [D]

10-25

11-24

0-99

7-26
7-76
0-50

4-62
4-97

o-:^5

2-85
3-04
0-19

1-52
205
0.53

104
1-36
0 32

0-78
1-11
0-33

0-66
0-87
0 21

D

, d

2-75

1-79

1 46

1-19

4-08

4-57

5 -.50

5-25

The differences here are more marked than those found in the previous comparisons,
four out of the eight amounting to over four times their respective errors. Bearing in
mind, moreover, the fact that all average values are higher in the case of the Atlantic
fish than the corresponding values for the Magdalen islands samples, it will be realized
that the difference in growth is here bv no means inconsiderable.

CA^ADIAy FISHERlEfi EXPEDITWS, 19V,-15

155

12. Graphical iUusf ration of the results obtained.— CuT\e> for the samples from
Magdalen islands and Xorthumberland strait have already been shown together in
one of the previous figures, it has therefore sufficed to give the curves for ^Nfagdalen
islands, l^orth Sydney and the Atln!itic coast ("fig. 42).

Ys ^it \s ^6 ^7 ■^a

It will be seen from this figure and the foregoing remarks, that the growth of
th3 Magdalen islands fish differs distinctly from that of the Atlantic herriug farther
C551— 14J

156

DEPARTMENT OF THE NATAL SERVICE

south, while exhibiting a considerable resemblance to that of the fish from North-
umberland strait, on the one hand, and ISTorth Sydney on the other. Fig. 42 shows
that the growth of the Magdalen Island herring may be more or less aptly charac-
terized as something midway between that of the Northumberland Strait and that of
the North Sydney fish.

13. Samples from Northumherland strait. North Sydney, and the Atlantic coast
compared. — Of the comparisons which still remain to be made, that of the Atlantic
fish (West Ardoise and Lockeport) with the herring from North Sydney, is the most
interesting. We can judge from the foregoing that the rest of the comparisons will
turn out much as with the samples from the Ifagdaleu islands, only with diiferences
more strongly marked. Table 44 shows, that such is the case.

Tablk 44.-^Growth of herring from Northumberland Strait (year-class 1903) com-
pared first with herring from North Sydney (year-class 1903 + 1904), then with
herring from Nova Scotia (year-class 1903 + 1904).

Locality.

tx

h

t:i

ti

^5

h

h

10- IS

6 4.5

4-94

2 98

1-.58

1 08

0-81

10-90

818

4-32

2 41

1 61

1 14

0-77

0 72

1 73

0-62

0 57

0 03

0 06

0 04

206

6 6.5

3-26

4 07

0-20

0 67

0 80

11 24

776

4-97

3 04

2 05

1 ."6

1 11

106

r;n

0 03

006

0-47

0-28

0 30

.3 1

5 0

0 1

0 4

3 6

4 7

6 0

Northiimberlanri Strait.

North Sydney

Difference (/))

I)

(i

Nova Scotia

Difference (Z))

D

d

0 72
0-78
0 06

1-20

0-87
015

3 7

Unfortunately, the observations available for comparison of the herring from North
Sydney with those from more southerly Atlantic waters are rather few. We have
therefore here taken, in addition to the 1904-03 year-class, also the younger fish of
1908, there being at any rate some of these in the samples from both waters.

Table 4.5 shows the comparison for fish of 1904-03.

Table 45. — Growth of herring from Nova Scotia compared with that of herring from
North Sydney. (Year-classes 1903+1904 in both cases.)

Locality.

h

ti

ti

^4

^5

^6

U

h

11-24

10 90

0 34

7-76
818
0 42

4 97
4 32
0 65

3 04

2-41
0 63

2 05
1-61
0 44

1 36
1 14
0-22

1 11

0 77
0-34

0 87

North Sydney

Difference {!>)

0-78
0 09

D

d

0 74

1-24

2-3

3-2

2-4

2-00

4-9

15

All averages save for t.^ are greater in the case of the Atlantic fish. Only in two
instances however, is the difference greater than three times its error.

Table 46 shows the comparison for the 1908 year-class; here also we find one or
"two marked differences, while the averages for all dimensions, save t-i are again
greatest in the case of the Atlantic fish. The unanimous testimony afforded by these
comparisons between the different age groups is, in my opinion, sufficient evidence
of a real diffe7*ence in growth between the fish from North Sydney and those in the

CANADIAN FISHERIES EXPEDITION, lOl'i-lo

157

more southerly samples. This difference is perhaps more pronounced when we look
at the calculated lengths, instead of the calculated increments, as the differences for
dimensions t, — t^ small, it is true, yet tending in the same direction, are then added
together.

Tablk 46. — Growth of herring from North Sydney and Nova Scotia compared.

(Year-class 1908.)

North Sydney.
Nova Scotia. . .
Difference [U).
D

*litv.

h

<2

h

U

U

10 40

11 16
0 76

9-65
7-72
1 93

416

4-78
0 62

2-64
3 57
0 93

l-7i'
2- 16
0 .37

1 65

4-28

2 58

3 21

218

1-30
1 37
0 07

0 64

14. Summary. — On glancing through the comparisons made in the last two
sections, we are led to the following conclusions: Samples resembling one another
in point of age-composition also exhibit great resemblance as regards growth.

The samples from Magdalen islands, Northumberland strait and North Sydney
(with the exceptional sample from St. Georges bay) exhibit a type of growth which may
to a certain extent be characterized as markedly distinct from the Newfoundland type,
while differing also to a lesser degree, albeit still pronouncedly, from that noted
among the herring from West Ardoise and Nova Scotia, which appear to form in thia
resjject a group apart

The growth of the Newfoundland herring is characterized by a modest commence-
ment in the first summer, proceeding well, however, from the third summer onwards.
The herring from the gulf of St. Lawrence have a good first summer's growth,
but owing to the slower growth in their later years do not, when older, exhibit the
samu average length as fish of the same age from Newfoundland and other waters.
The herring from North Sydney show good growth for the first two years; compara-
tively poor, however, later on ; nevertheless, they exhibit, on reaching a considerable
age, a very respectable average length, inferior only to that of the herring from the
southern Atlantic waters. These last may be said to grow well for the first five or
six years, whereby they outdistance the fish from other localities.

XIII. APPENDIX.

OBSERVATIONS AS TO SEASONAL GROWTH IN
YOUNG HERRING.

Some samples of young herring in the material collected afford some evidence as
to the manner in which the summer growth proceeds in the different Atlantic waters.
This, taken together with what we have learned regarding the growth of the older
fish, furnishes some rough idea, as to the main features of seasonal growth in Cana-
dian waters, though a complete survey is not at present feasible.

The sample of small herring from Port au Port, mentioned on p. 137, seems to show
that most of the summer growth in that area has taken place before the middle of
August. Fig. 43 shows the observations taken together, with curves indicated for
seasonal growth during the second and third sunnners, as far as can be calculated from
the scanty data available.

The samples of young fish from the waters between the Gasne coast and Prince
Edward Island exhibit a growth similar to that of the adult fish from ^VFaiidalen
islands and North\nnberland strait albeit it does not seem possible to class tliem defi-
nitely witli either of these two STOups.

153

DEPARTMENT OF THE NAVAL SERVICE

Fig. 44 shows the observations obtained from these samples, arranged in the
same manner as in fig. 48.

cm

7-

Pc

rt

au

Par

I

vr-

^.

'

V"'.

()

/T

1

1

t

/

2-

I

1

Jan. March May July Sept Nov

Fig. 43.

Gaspe -

Pr E.dw I.

%

,*^. ^r."?-^

Jan. March May July ^ Sept Nov.

'■ Fig. 44.

Finally, a couple of trap samples, from Souris, Prince Edward Island, and a
drift-net haul from the vicinity of cape George (station 53) include some young fijsh,
the seasonal growth of which is indicated in fig. 45.

cm
8

-7

So

uri

5 -

C.G

eor

ge

,<

^--

—

._ -

. (.

/^

^/

•ler

• i¥

<v '

-A-

»o«*'

^ .

•

'"

;

/

4kh.

sum

mer

. O

/
/ 1

. I

;

7

■•■''''

/

Jan. March M.3y Julv SepL Nov:

These later samples give a more definite idea as to the time when summer growth
of the younger herring in these waters begins, as in one of the samples (early June)

C'AXADIAN FIS^HERIES EXPEDITION, 191 'rl5 159

the fish had not yet commenced their growth, while the remaining samples revealed a
distinct new summer helt on the scales.

An interesting feature in connection with these fish is the fact that tlic summer
growth commences so late. Off the coast of Norway, the new summer growth com-
mences in April ; but far up in the Baltic, near the coast of Finland, similar conditions
are observed. Hellevaara (IV) who has investigated the herring of these waters,
observes in this connection; " Not imtil the 27th of June did I observe that the scales
had begun to grow on the young fish 1 or 2 years old; but not on those which had
reached maturity.''

XIV. EESULTS OF AGE AND GROWTH STUDIES, VIEWED IN THE LIGHT
OF OBSERVATIONS AS TO RACIAL CHARACTERS.

In the foregoing I have endoavinired, by analysis of the age determinations and
growth measurements made, to arrive at a satisfactory solution of some of those
problems which group themselves about the two more comprehensive questions, as to
the numerical proportions of the different year-classes, and the growth of the fish in
different waters. It became very soon apparent, during these studies, that the area,
within which the samples analysed were collected, presented contrasts often most
pronounced, and it would therefore be natural to consider both age and growth obser-
vations against the background, so to speak, of the third problem, viz., whether several
more or less distinctly different races of herring could be shown to e.xist within
the area investigated.

We may therefore, in conclusion, glance at this question, while considering the
observations as to racial characters, and discussing the possibility of employing growth
observations as a means of distinguishing races.

The results of the age and growth studies bearing on this problem may be briefly
summed up as follows: The different waters exhibit different conditions with regard
to the age-composition in the samples and the growth of the fish.

In seeking foij the cause of the differences observed between samples from
different waters, and of the resemblance between those from the same locality, we are
naturally led to the supposition that several local tribes or races of herring must
exist, each having its own particular area of distribution. Without such hypothesis,
it would appear difficult to understand how the different waters could differ so
remarkably with regard to age and growth of the fish, as seen, for instance, in the
marked dissimilarity between the 'herring of the ^Magdalen islands and those taken off
the coast of Newfoundland, despite the short distance — but a few days' swim — between
the two localities. By presupposing the existence of such local races, we are at least
able to accept without surprise the fact that such differences do exist, albeit we can,
from our present slight knowledge of the subject, form but vague and uncertain ideas
as to how the differences in question may have arisen.

It would therefore be must useful, if other methods of investigation could be
brought to bear upon the problem as to existence of local races in these waters. One
in particular immediately suggests itself, to wit, that formulated by Heincke for the
very purpose of studying the racial distribution of the herring, by arithmetical descrip-
tion of the morphological features.

As mentioned in the introduction, countings of vertebrae, fin-rays, and keel-
scales were carried out with a number of herring from different waters, at the time
the material was collected. These observations should, however, as Dr. Hjort has
pointed out in his preliminary report, only be regarded as of a tentative character,
the samples in question being few and small. Hence, I can, as a matter of fact, add
but little to what Dr. Hjort lias already stated with regard to these observations;
nevertheless, it may yet be of interest to consider them here in connection with what
has been set forth in the foregoing pages respecting age and growth.

160

DE PART M EXT OF THE XATAL SERVICE

The features noted were as follows: Total number of vertebra; (Vert. T.);
numerical order of first vertebra with closed h^mal arch (Vert. H.) ; number of fin-
rays in dorsal (Dors.); and in anal fin (An.); and nxnnber of keeled scales between
the ventral fin and the anus (K.).

I hiave worked out the standard error of the averages for each of these characters
in the several samples, and found that the resulting error of the differences in all
cases may, without risk of serious inaccuracy, be taken as about 0.17, the actual
figures being sometimes slightly higher, sometimes a little lower than this value. In
making comparison between two averages, then, a value of at least 0-5, or thereabouts,
will be required before the differences can with any great degree of probability be
regarded as statistically significant, i.e., due to other causes than accidental fluctuation.
Where the differences of several averages tend in the same direction, smaller values
may naturally be taken as significant.

In the autumn of 1915, however, I made an observation which seems to suggest
that it may, in certain cases, be necessary to demand a higher order of magnitude
in the differences between two averages before deducing therefrom the existence of
variety in race. And as this particular feature has not, as far as I am aware, been
touched upon before, I have thought it advisable to mention it here.

While investigating the number of vertebrae in a sample of young herring from
the north of Norway, in the autumn of 1915, I found that the fish of about 1-| years
old (numbering forty-nine in all) averaged 57-37 vertebra% while those of about 2|
years (241 specimens) showed an average of 57-72. The difference between the two
age groups in this respect was 0-36 z±z 0-11 giving 0-9995 for the probability that it
was not due to accidental fluctuations of sampling. It would thus seem that variation
may occur in the number of vertebrae of the different year-classes (year-class variation
as opposed to age variation). In samples where a large majority is furnished by a
single year-class, therefore, such year-class variation may possibly affect the results
to a certain degree, while on the other hand, this is hardly likely to be the case in
samples consisting of several year-classes, all more or less equally represented. As
samples of young herring are particularly liable to exhibit such majority of a single
year-class, it will be prudent to regard them as less truly representative of the race to
which they belong.

Table 47 shows the average values for the seven samples examined as to number
of vertebrae, etc. The values are here carried to the first decimal point, a value of
about 0-5 being, as we have seen, required to make the difference statistically signifi-
cant. There are one or two slight discrepancies between this table and the correspond-
ing one in Dr. Hjort's preliminary report. One of these (West Ardoise, number of
vertebrae) is due to the omission there of an extreme variate which has been included
here ; another owing to a slight error in the arrangement of the variates ; the remain-
der to the loss of some of the sheets on which the figures had been noted; none arp.
however, of any grave importance.

Table 47. — Eacial characters. Averages for samples from different localities.

Locality and Date.

Characteristics.

Dors.

An.

K.

Vert.
H.

Vert.
T.

Newfoundland, west coast. Autumn '14

Magdalen Islands, May 1914

Northumberland S-trait, May 21, 1914

W. Ardoise. Aug. 10, 1914

Lockeport, Nov. 1914

BayofFuiiHy, Nov.. 1914

(jloucester, Mass. Nov. 1914

Old, mature, developing sex. org.

Old, mature, ripe

Old, mature, ripe

Younger, mature, ripening

Younger, mature, ripe?

Young, immature

Young, immature .

200
18-3
1.S 3
18 5
20-3
18-7
19-9

13 2

25 0
2.0-4
2.5-2
2.5 4
25-2
25-0
24 9

56-8

dAAADfAX FiSHERIEf; EXPEDITIO\, U)1',-1o 161

From the figures here shown, it would certainly seem very likely that the method
in question might serve to define the differences between the herring from different
parts of the Canadian waters. Thus the sample from Newfoundland, for instance,
differs distinctly from the Magdalen islands and Northumberland strait samples as
regards the number of rays in the dorsal fin, which character likewise seems to indicate
a difference between the herring of the Magdalen Islands and Northumberland strait
on the one hand, and those of the Atlantic coast on the other. This character also,
therefore, might possibly prove of importance if the error of the averages were
reduced by increasing the number of specimens in the samples. Somewhat the same
applies, indeed, to the number of vertebrae; the present samples are too limited to
reveal any absolutely indubitable difference in this character.

On comparing the figures for the sample from Northumberland strait with those
of the one from Magdalen islands, no essential difference is apparent, and one is
reminded of the great resemblance in point of growth exhibited by the samples from
these waters, with the good 1903 year-class common to both. It would be interesting
to investigate the localities in question more closely, with the aid of more extensive
material, in order to determine, if possible, whether the differences in growth and in
age-composition found, warrant our considering the herring of these two waters as
separate groups.

The sample from West Ardoise differs strongly from that taken at Lockeport, by
the smaller number of rays in the dorsal and anal fins. The differences are so great
that it seems almost certain they cannot be accidental. Here again is a ixtint which
might well be investigated further with a larger amount of material. Possibly the
results might then lead to a definite distinction between several forms of herring
along the Atlantic coast, based on the study of morphological characters and growth
measurements. In our present investigations, the paucity of materiaf rendered it
impossible, as already mentioned to demonstrate with certainty the existence of
any difference in point of growth between the herring of Lockeport and those of West
Ardoise. In further investigations it would also be well to include samples from the
north side of Cape Breton island, in order to determine the character of these fish
more accurately than it has here been possible to do ; the same applies to the waters
between Port Hood, Souris, and cape George, as well as the more southerly parts of
the Atlantic waters of Canada.

One special subject for growth investigations which, owing to the favourable
conditions in these waters, have every chance of success, is the distribution of the her-
ring in the gulf of St. Lawrence, studied by means of quite small samjjles of old fish,
examined as to growth. The very remarkable difference in growth between the her-
ring from the southern portions of the gulf, and those from th3 coast of Newfoundland
renders it, as far as I can see, an easy task to determine, even with small samples,
whether the fish in question can be said to belong to one or the other growth type.
Such identifications of the herring could be carried out in a manner similar to the
method of Heincke for the identification of herring by means of morphological char-
acters. Heincke's method may be briefly described as follows : It is desired to ascer-
tain whether a given specimen, of which certain characters have been determined by
count and measurement, more resembles in such respects the one or the other of two
races in which these same characters are known (average and variation). The first
step is to ascertain in what degree the six^cimen differs, as regards each separate char-
acter, from the average values for same in the one race, the difference in each case
being expressed in units of the respective standard deviations. The differences thus
obtained are then squared and added together. Similarly, the deviations of the speci-
men from the average of the other race is then determined, the differences here being
expressed in units of the respective standard deviations for the race in question.
The specimen then differs in the lessor degree — i.e., resembles more — the race for
which the resulting sum of the squares of the differences is the less. Table 4S shows

162

DEPARTMENT OF THE NAVAL SERVICE

the order of the calculations. Tlie example here used was a tish from one of the New-
foundland samples, belonging to the lOO-t year-class ; the values for the different incre-
ments (t) for the specimen in question are shown in the first column of the table.
The second column gives the corresponding average values for all Newfoundland fish
investigated; the third the deviation of the specimen from these averages; the fourth,
the standard deviations for these averages in question; the fifth, deviations of the
specimen divided by the respective standard deviations (i.e., deviations of the speci-
men expressed in units of the corresponding! standard deviations) ; the sixth, these
deviations squared; and finally, the sum of these squares is shown at the foot. The
second half of the table is drawn up in a manner exactly corresponding to this, the
specimen being here compared with the averages for the 1903 year-class from the Mag-
dalen islands. The resulting sums of the squares are, it will be noticed, highly dissi-
milar; that for the comparison with the Magdalen islands averages being more than
ten times the figures resulting from comparison with the averages for the fish to
which the specimen actually belonged.

It will be interesting to refer to table 48 showing the method of comparison
between growth values for a single herring and the corresponding average figures for
the herring of two different waters, according to the principle of " least squares."

Table 48. — Example showing the growth of a single herring compared with average
growth of the herring from Magdalen Islands and Newfoundland by the
method of least squares.

Individual herring, to be tested. .
Average from Newfoundland san

pies

Deviations from Newfoundland

averages 5

Standard deviations for Newfound

land samples cr

8
~~ Newfoundland

Gf-

Averages for Magdelen Islands
samples. ...

Deviations from Magdalen Islands
averages 5

Standard deviations for Magdalen

Islands samples tr

5

c-r

tx

h

(3

5 1

U
31

h
30

h

ti

h

h

71

7 0

1-7

11

10

11

6 1

7 0

5 4

3 3

2 7

2 1

15

11

0-9

10

0 0

0 3

0 2

0 3

0-4

0-4

01

0-2

1-69

113

0 95

0 67

0 65

0-57

0-47

0-31

0 29

0-59

000

0-32

0-30

0-46

0 70

0 85

0 32

0-69

0-35

0 00

010

0 09

0-21

0-49

0-72

0 10

0-48

10-3

7-3

4-6

2-9

15

10

0-8

07

0-7

3 2

0-3

0-5

0 2

1-5

0-7

0 3

0 3

0 4

1 63

1-38

0-98

0 59

0 46

0-28

024

0 20

0 22

1-96

0 22

0-51

0-34

3-26

2 -.50

1-25

1 50

1-82

3-84

005

0-26

012

10 63

6-25

1-56

2-25

3 31

tia

0 8
0-7
0 1
0 25
0-40

016

0-7
0 1
0 21
0-48

0-23

Resulting s an of fz\ ■ For comparison with Newfoundland averages 27.
Resulting sum of /"_ | • For comparison with Magdalen Islands averages 28'5.

The specimen here dealt with was one of twent.y others selected for examination
by this method. Ten of these were taken from one of the Magdalen islands samples
among the 1903 year-class, the requisite standard deviations for this year-class having
been previously computed; the remaining ten were selected from fish of the 1904 year-
class in one of the Newfoundland samples. In order to ensure the obtaining of an

CA\AIJ1A\ Fh-^HERIhJs EXI'EUITIOX, 191',-lo 163

absolutely independent seleetiou, the task of choosing out specimens was delegated to
another party, who simply noted down twenty of the numbers which had been assigned
in the tables to the fish of the mentioned year-classes in the two samples. The sample
from Newfoundland was, moreover, the one with averages differing most from the
total average for all Newfoundland samples, the deviation tending in the direction
of the averages for the Magdalen islands. It may therefore be admitted that the
results obtained will not present any unjustifiably favourable view of the possibilities
inherent in such comparison. It was found that in seventeen out of twenty instances
the sum of the squares was the less in comparison with the averages for those fish to
which the specimen in question belong. The reverse was found in the case of one
specimen from the Magdalen islands, and two from Newfoundland, these differing
more from the averages of the fish whence they were taken. This result seems to
suggest that it should be possible, by means of the figures obtained from growth
measurements, to determine, in many cases at least, whether an old fish taken in the
gulf of St. Lawrence belongs in point of growth to the type found off the ;^[agdalen
islands, or to that found in the Newfoundland waters. In order to obtain the best
results, good averages would be required, i.e.. it would be necessary to examine large
samples, taken during the spawning season, and on the actual spawning grounds, such
choice of time and place being the best means of procuring " pure " samples, without
admixture of foreign elements. The comparison should be made not as has here been
done with averages for different classes (Magdalen islands 1903 and Newfoundland
190-i) but with averages for the same year-classes in samples from the different
spawning grounds.

As to how far any similar individual distinction may properly be made with regard
to the herring in other Canadian waters, we cannot at present decide anything with
certainty, the material from the Atlantic areas being insufficient. iNfost probably,
however, we should in the majority of cases be able to determine whether a herring
tiken between Cape Breton and Newfoundland should be regarded as a Newfoundland
herring in the strict sense, or not. always pro\'ided that the investigations are so con-
tinued as to furnish a sufiScient fiuantity of material for computing the averages (with
standard deviations).

LITERATURE REFERRED TO.

I Dahl, Knut. The scales of the herring as a means of determining
age. growth and migration. Rep. on Norweg. Fishery and

Marine Investig.. . . .^ Vol. II. No. 6. 1907

II Dahl, Knut. The assessment of age and growth in Fish. Internat.

Rev. d. gesamt. Hydrobiol. u Hydrograph Bd. II. H. 4-5.

III Heincke, Fr. Naturgesehiehte des Ilerings. Abhandl. des Deutsch.

Seefischerei-Vereins Bd. II, 1898

IV Hellevaara. E. Undersiikningar rorande stromingen i sydviistra

Finland. Finlands Fiskeriar Bd. I, 1912.

V Hjort. Johan. Fluctuations in the Great Fisheries of Northern
Europe. Rapp. et Proc.-verb. du Cons. Internat. iwur I'Explor.

de la Mer Vol. XX, 1914.

VT Hjort, Johan. Investigations into the Natural History of the
Herring in the Atlantic Waters of Canada.
Suppt. 5th Ann. Rep. Dep. of Naval Service, Ottawa, 191.o.
VII Hjort. Johan and Lea, Einar. Some results of the Internat.

Herring Investigations, 1907-1911. Pub. de Circonst.. No. 61, 1911.
VIII Hoffliauer, C. Die Altersbestimmung des Karpfens an seiner

Schuppe. Allg. Fischereiztg .No. 19, 1899.

IX Lea. Einar. On the methods used in herrinii- investigations. Publ.

de circonst No. 53, 1910.

164 DEPARTMENT OF TEE NAVAL SERVICE

X Lea, Einar. A study on the Growth of Herrings. Publ. de

Circonst No. 61, 1911.

XI Lea, Einar. Further studies concerning the methods of calculating

the growth of herrings. Publ. de Circonst No. 66, 1913.

XII Lee, Rosa M. An Investigation into the Methods of Growth-Deter-
mination in Fishes. Publ. de Circonst No. 63, 1912.

XIII Reibisch, F. Eizahl bei P. platessa u. die Alterbest. dieser Form

aus den Otolith. Wiss. Meeresunters N.F. Bd. IV, Abt. Kiel, 1899.

XIV Winge P. On the Value of Rings in the Scales of the Cod as a

Means of Age Determination. Meddelels. fra Komm. f. Haver-
undersog., Serie Fiskeri Bd. IV, 1915.

CANADIAN FISHEIMES EXPEDITION, 11)141915

BIOLOGY OF ATLANTIC WATERS OF CANADA

GROWTH OF THE YOUNG HERRING rSOCALLED
8ARDINES) OF THE BAY OF FUNDY

A PEELIMINARY REPORT

BY

A. G. HUNTSMAN. B.A., M.B., of the University of Toronto.
Curator, Dominion Biological Station, St. Andrews, Xeiu Bntnsivicl-.

In the spring of 1915 Dr. Hjort proposed in connection with tlie extended
investigations in 1914-15 that I study the young of the herring (Clupea harengus) or
** sardines " of the Bay of Fundy to determine if possible how hirge they were during
the first winter, and the amount of growth during the year. The numerous Canadian
weirs that are fished throughout the greater part of the year to supply the sardine
factories chiefly in Maine were practically certain to furnish an abundance of material.

Owing to the work that was being prosecuted in tihe gulf of St. Lawrence it was
not possible for me to examine the material in the fresh state except at the beginning
and end of the season. It was necessary to rely upon salted material.

The material has been collected in large part by the engineer of the Biological
Station at St. Andrews, Mr. A. E. Calder. When circumstances permitted, he collected
samples weekly. The material has proved to be far from complete enough to settle the
points in question. This is particularly the case with regard to the smaller fish,
popularly known as " brit," which are for the most part too small to be satisfactorily
taken by the nets used in seining the weirs. Not only will they pass through the nets
in seining, but when present in quantity they will not be taken out, being too small for
canning. Although there are many gaps in the material, the results are not without
interest.

It appeared desirable to use the scale method of determining the age and the
jearly amount of growth; but the material presented such great difiiculties owing to
the indistinctness of the winter rings that this was abandoned and the method of
measurement, instituted by Petersen, alone was used.

The samples were measured on one of the usual boards, divided into centimetres,
with the divisions at the half centimetres so that in each case the measurement was to
the nearest centimetre. This gave centimetre groups for statistical treatment. To
facilitate accurate determination of the length, the measuring board was marked on

166

DEPARTME\' OF THE NATAL SERVICE

either side of the mid-line with a series of parallel diagonal lines, making an angle of
4(r"degrees with the mid-line. By aligning the margins of the tail with these it was
possible to spread the tail to an arbitrary, constant angle of 80 degrees.

Owing to the mixture of herring of different age groups in the samples, it was not
feasible to take the average size in treating the material. The smallness of the numbers
representing certain age groups in many of the samples rendered the results unsuitable
for extensive statistical treatment. The only feasible method was a compromise and
therefore somewhat open to objection.

The relative frequency of the various length groups in a sample indicated whether
the sample consisted of more than one age group and also showed the mean size in each
group. The various groups could in that way be traced through successive samples and
their rates of growth determined.

The following table gives the results of the measurements : —

Length in Centimetres.

Locality.

Date.

f, 14..

7

8

y

10

2

11

3

12
38

13

140

14

89

15
16

16

2

17
2

18
1

19

1

20

21

22

23

24

25

26

27

28

Back Bay

St. Anrlrews

IV, If...

3

5

16

43

79

59

26

3

3

4

.■!

St. Andrews

V, 13..
V. 24..

6

29
4

29
103

12
92

11
32

25
15

49
10

83

45

1

27

3

4

5

2

St. Andrews

St. Andrews

VI, 2..
VI 15

1

32

150

76

46
22
183

32
53
29

18

68

9

10

60

3

5
40

1

5
25

7
12

2
3

1
1

1

St. Andrews

VI, 28..

St. Andrews

VII, 20.
VII, 27..

7

1.55

28

47

68

17

20

10
17

4

18

1
.38

1
36

22

6

^

St. Andrews

2

5

St. Andrews

VIII, 12..

5

9

8

71

77

14

17

29

38

29

13

3

2

St. Andrews

VIII, 1!!..
VIII, 30..

1

9
]

2
13

21

2

60
6

30
11

25
6

26
8

38
24

37

40

26
32

8
15

2
3

2

i

2

1

St. Andrews

St. Andrews

IX, 7..

1

3

10

5

3

6

3

o

12

49

53

30

15

11

1

1

5

i

Jrmesport

IX, 13.
IX, 14..

1

1
4

19
10

62
51

52
98

45
47

42
20

21

2

20

s

6

2

L'Etang

2

2

Lei)reau

IX, 14..

i

15

10

S

1

6

12

14

26

69

58

25

8

3

Pocolopan

IX, 14..
IX. L5

"i

3

8
2

14
1

7

33
2
1

55

15

3

39
51
16

24

(59
53

9

49
37

2
21

10

17

9

4

1

■3

i

Grand Harbour

Boc abec I

IX, 16..

Bocaljec II

IX, 16..

2

23

24

36

60

98

50

13

1

1

Bocabec III

IX, 16..

4

11

^

6

10

9

18

59

76

45

10

Oak Bay

IX, 28..

]

9

10

7

1

1

1

11

55

83

37

7

4

o

2

2

1

Bocabec.

X, 4..

3

10

5

2

1

5

38

47

63

41

17

6

1

St. Andrews I

X, 14..

1

6

23

25

27

23

19

44

64

68

67

47

14

9

5

7

1

1

2

St. Andrews II

X, 14..

12

28

18

17

20

24

45

36

46

35

20

8

7

2

2

2

St. Andrews

X, 25..

1

25

32

19

8

10

23

51

60

19

12

2

St. Andrews

X, 20.
XI, 3..
XI, 10..

20

124

16
9

69
49
32

5
75
49

1
38

28

1

16
19

.38
26

46
43

24
61

6
.37

13

3

i

St. Andrews

St. Andrews

St. Andrews

XI, 23.

12

43

58

26

18

13

31

23

10

3

1

Back Bay

XI, 29..

2
1

i.s

9

67
12

35
32

47
34

.33
21

49
17

30
8

10

7

5

6

6
7

3

8

15

's

4

1

St. Andre w\s

XII, 6..

Bliss Harbour

XII, 21..
XII, 24.

2

13
2

26
4

38
17

91

83

88
91

37

72

24

16

9
6

2
4

7

1
2

Mascarene

Bliss Harbour

XII, 29..

2

5

18

95

111

63

21

10

4

6

4

2

4

Two of the samples may be said to be homogeneous, consisting of only one age
group. They are those of June 28 and October 29. In both the actual range in size is
6 cm. (9-14 and 11-16) and the practical range is only 4 cm. (9-12 and 11-14) or perhaps
3 cm. (9-11 and 11-13). There can be no doubt that in these cases we have to do with
only one age group. The curve for the sample of June 28, obtained by plotting the
lengths against the numbers of individuals is given by the continuous line in fig. 1.
Evidently too few length groups have been taken to give the most satisfactory curve,
but we will not be far astray in taking 10 cm. as representing the mean length of the
herring in the sample of June 28 and 12 cm. for those of October 29.

CANADTAy FisIlERIEfi EXPEDITION, 191 ',-15 167

If we take the sample of October 4 and plot a curve to show the frequencies <if the
various length groups (interrupted line in fig. 1) we see very definitely a bimodal
condition with two age groups represented, for one of which the length of 12 cni. may
be taken as representative and for the other 19 cm. There is, however, a decided
diflFerence in the ranges of the two groups. The smaller one may be considered to have
a range of 4 cm. (11-14) and the larger of 8 cm. (16-23). This might be due to the
phenomenon of dispersion, the older group showing a broad low curve, and the
younger group a narrow high one. I do not believe that this is the full exjjlanation.
The range is too great in the older group. It probably indicates that the older group
is only apparently homogeneous, that it really consists of two age groups so similar in
size as to fuse and give a good unimodal curve. Other considerations to be mentioned
later support this view.

The sample of September 28 shows a similar condition. The practical ranges of
the two groups would be 3 and 5 cm., respectively. The significance of this would seem
to be that by the third year the spring and fall spawned schools have fused into a single
group.

The third sample (III) of September 16, from Bocabec shows imperfectly a tri-
modal curve (fig. 1, dotted line). The sizes representative of the three groups may be
taken as 12, 15 and 19 cm. The ranges are 3 cm. (11-13), 3 cm. (14-16) and 5 cm.,
respectively. The first and third of these groups are evidently identical with the two
groups of the sample of October 4. The second group (15 cm.) was doubtless present
in the latter sample but not in sufficient numbers to appear distinctly.

Let us designate these three groups A (19 em.), B (15 cm.) and C (12 cm.).
B and C give a bimodal curve with a total range of 6 cm. The growth of the smaller
group (C) appears to continue farther into the fall than that of the larger group (B).
This would bring them close together and make them fuse into one group vrith a
range of 5 cm. and a mean size of 14 cm. as seems to be the case in the samples of
November 3 and November 10. (for the latter see the curve in fig. 1 with alternate
dot and dash). In this latter sample the larger group with a mean size of 19 cm. is
evidently A and the smaller group with a mean size of 14 cm. represents (if our inter-
pretation be correct) B and C fused. In the spring of the year group A seems to have
been in the same condition as shown in the sample of April 10, with a range of 5 cm.
and a mean size of 14 cm.

The degree of fusion of B and C and the relative abundance of the two groups in
the various samples give a varying picture as shown in the samples of October,
November, and December from St. Andrews.

In the middle of September samples from widely separated localities along the
coast were examined and also a number of samples from the same locality in order to
determine whether the mean size of an age group varied greatly in the different locali-
ties and in different samples from the same locality. These samples were in great
part obtained through the courtesy of Captain Calder of the Seacoast Canning Co.,
Eastport. The localities were Jonesport (Maine), Grand Harboiir (Grand Manan),
Lepreau, Pocologan, L'Etang, and Bocabec. The samples sht»wed uniformly a great
preponderance of the A group. The mean size varied, being IT cm. (Jonesport,
Lepreau, and Pocologan), 18 cm. (L'Etang), and 19 cm. (Grand Harbour and Boca-
bec). Evidently there is an appreciable difference in the size of the same age gi'oup
from different localities.

Samples were taken from several boats bringing herring from Bocabec on
September 16. These showed uniformly a preponderance of the A group with in each
case a mean size of 19 cm. The same is shown in a sample of September 28 from Oak
Bay. This shows that herring from the inner side of Passamaquoddy bay may be
considered uniform and treated together. Those from points as far away as L'Etang
must be treated separately. The differences shown in the samples of September 16
from Bocabec indicate the amount of uncertainty to be associated with deductions

168 DE PANT M EXT OF THE NAVAL SERVICE

luade from measurements of such small lots of individuals. All three show in their
curves summits at 19 cm. Two show summits at 15 cm., and the third a definite step
in the curve at 15 cm. Only one shows a summit at 12 cm., the other two samples
having no individuals of that or neighbouring sizes. Summits (or steps) are therefore
quite constant for the same age group in the same locality at any one time.

These examiples will serve to show the manner in which the results of the measure-
ments have been interpreted.

To determine the rate and period of growth of each of the different age groups,
the representative length of each group, in each of the samples from Passamaquoddy
bay in which it was represented in sufficient numbers, was determined in the manner
described above. These lengths have been plotted against the dates on which the sam-
ples were obtained, in fig. 2. For each group a curve has been drawn connecting the
circles that indicate the length of the group at different times. Where there are con-
siderable gaps the curves have been continued with interrupted lines. There are occa-
sional points that do not fit into the general scheme. Those of November and
December, intermediate between B and C we have already interpreted as due to more
or less complete fusion of B and C.

The fresh fish measure somewhat larger than the salted. For this reason the
lengths in the samples of May 24 and September 16, seem high compared with the
others. The samples of June 15 and November 3, show groups with mean sizes of
12-5 cm. and 18 cm. respectively. In these cases we may have group C of the preced-
ing year which has failed to fuse with B of the same year, whereas in A these two
groups are constantly fused.

In fig. 2 we have a graphic representation of the growth of the three groups A, B
and C during the year. The period of growth for A and B is from May to the end
of September. For C the beginning of the period is not shown, as at that time the
fish were too small to be taken by the nets. It appears to continue later for this group,
at least well on into October. The rate of growth for B and C is somewhat less than
2 cm. a month in the middle of the summer when the growth is most rapid. The rate
for A is less, about 1-5 cm. a month as the maximum.

In many of the samples larger fish were present, but their numbers are so small
as to be unsatisfactory for. a determination of their Tiiean sizes and growth. The little
evidence there is, shows a group beginning at 1!) cm (April 16 and May l^i!) and grow-
ing to 23 cm. (October 14, October 25, November 10, and December 6). Also a group
reaching 26 cm. by September 7.

The determination of the ages of these groups presents difficulties. Groups B and
C are quite evidently less than one year apart in age. The lack of material less than
7 cm. in length must leave the question in doubt but it is most reasonable to suppose
from the rate of growth shown in 1915 that group B, beginning at a length of 8-5 cm.,
must have already passed through a full season's growth. The well-established fact of
decrease in growth rate with increasing age would necessitate this interpretation,
unless there were still greater growth during the first year. We would then reach the
conclusion that group B was spawned in the spring of 1914, reached a length of 8-5
cm. by winter and in 1915 grew 6-5 cm. to a length of 15 cm. Group C would have
been spawned in the fall of 1914, have reached a doubtful length by winter, perhaps
5-5 cm., and in 1915 grown perhaps 7 cm., reaching a total length of 12-5 em.

Group A is evidently in its third summer and consists of a mixture of both
spring and fall spawned fish. In the third year, therefore, the herring grow from a
length of 14 cm. to a length of 19 cm. The group growing from 19 cm. to 23 cm.
would consist r f hf'Tring in Iheir fourth year and those reaching 26 cm. of perhaps five
year old fish.

CAJSAniAX FISHERIES EXPEDITIOX, 191 ',-15

169

This interpretation maj' be expressed in the folluwinff table:

First Year.

Second Year

Third Yf-ar.

Fourth Year

Fifth Year.

Size,

Increase

Siz

15
12-5

Increase
5

Size
19

Increase
4

Size
23

Increase
3(?)

Si/e

Spring spawned

Fall n

85 cm.
5-5cm.(?)

6-5

7(?)

28-;?)

I have a small quantity of very young herring collected in the tide ripplings in
Passamaquoddy bay in June, 1911. Two small lots were picked up in dip nets at an
interval of one week. Eleven individuals taken on June 19, range from 3-7 to 4-8 cm.
in length, with an average length of 4-4 cm. Twenty-six individuals taken on June
20 range from 4-3 to 5-5 cm., with an average length of 4-9 cm. This gives a growth
of 0-5 cm. for one week. This is higher than the June rate for group B, but nearly
equivalent to the August rate, as shown in fig. 2. A continuance of this rate to
September would give fish averaging about 9 cm. These fish must have been spawned
in the spring of 1911. The fall spaw^iers which spawn at Grand Manan and on the
Nova Scotia shore do not begin until the later part of July. This confirms our inter-
pretation of group B as fish spawned in the spring of 1914.

A comparison of these results with what has been found in Europe with entirely
different methods shows a fairly close agreement. By studying the increase in the
zone on the scale of the herring outside the last winter ring in a series of samples
taken during the years 1910 and 1911 Lea has shown (Publ. de Circonst., No. 61, 1911)
that in the herring off Norway, growth takes place during the summer from April to
September. This growth period is of the same duration but a month earlier than for
our coast.

As concerns the amount of growth, Lea found it to be 7 cm. in the third summer,
which is much higher than what we have found. By calculations based upon the dis-
tances between the winter rings, Hjort (Publ. de Circonst., No. 53, 1910, p. 23) found
that for 246 spring-spawned fish the average growth in successive years was 8.3, 7.1,
5.9, 3.6, 2.4, and 1.7 cm. Our corresponding figures are 8.5, 6.5, 5, 4, and 3 cm. For
80 autumn spawned fish he fovind the following amounts 12.6, 5.1, 3.6, 2.6, 1.6, and
1.1 cm., believing that the first figure really represented two seasons' growi;h. Our
corresponding figures are, 12.5, 5, 4, and 3 cm. The agreement is as close as could be
expected, considering the imperfection in our material. We have also not been able
to separate the spring spawned from the fall spawned after the second summer.

It would have been very valuable to have correlated the positions and number of
the winter rings with this study of the growth from measurements. In the material
examined it has been possible to make out the rings clearly only in a small number of
cases. What has been seen on the whole corroborates the above mentioned interpreta-
tions as to the ages of the various groups.

CONCLUSIONS.

The data, though incomplete, indicate that: (1) there are both spring and fall-
spawned young herring (sardines) in the Bay of Fundy; (2) the spring spawned
schools reach a length of about 9 cm. (3.5 in.) by the first winter and of about 15 cm.
(6 in.) by the second winter; (3) the fall-spawned schools reach a length of about
12-5 cm. (4 in.) by the second winter; (4) the growth during the third season is about
5 cm. (2 in.) ; (5) the growth during the fourth season is about 4 cm. (1-5 in.) ; and
(6) the x>eriod of growth is from May to September.

It is most desirable that this study be continued in order to either confirm or
refute these tentative conchisions and to extend the observations.

6551—15

170

DEPARTMENT OF THE XATAL SERTIOE

CM

in

01

03
03

.-1

CO
o

CVJ
01

1-1 e

1-1 N)

•H

CO

•1
03

r-^

«H

iH

O
•-<

a>

00

1-

1

/.

ll

CD

•I

/

1
1

,.-';•

->

■<*l

...-

^

o

V

- \

c • - . .

» 1

s.

^1

/

,' \

y'

'. 1
■■. 1
\ 1

\

'\

f

2

5

"\^

/

tic

"3;

— —

"

\

2
'3

c

"

■— -

3

"~^~~~"

^^

-^

<D

ik

oino uo oiooiooio oio

OOCDin COWO<3>NCOt*CO.-4

f^

CA.V.1D7.4A' FISHERIES EXPEDITION, 1914-15

171

19
IS

n

16
IS

13

12

11

10

9

8

7

OjG

gy tjO

• 0 IS

A

!

■

— £

^

9

/

9

/

/
/

: CT

_B_

A L

/

99

o

f= — =

1

/

f^

_Q.

1

r

o

/

a<;

3 '-

'

!

/

P

'

y

/

i

' — I

1

o

/

/'

B

-J

/

1

/

/
/

Jan. Feb.

Mar.

Apr.

Kav

JliU.

Jul.

Au(j.

^e,Y

Oct. 1 Nov. iDecl

Fig.

Curves showing growth of Hening in 1915c The numbers
incUcate the length in centimetres.

•

'Noie (December 6, 1916) • — A continuation of the investigations during this year
has given results which agree well with those of last year. This last season differed
from that of 1915 in that the '' sardines " as a whole were small. This was due to
the practical disappearance of the A group by the end of July, the B and C groups
then in turn predominating. The A group was not as homogeneous as in 1915, con-
sisting of varying proportions of its elements (B and C of the preceding year). It
could therefore not be traced with any certainty.

The B gi'oup appeared at the end of May with an average length of about 10 cm.
It was, however, mixed with larger fish until July and could be followed with difficulty.
After August few were obtained. By October it had reached a length of 15 cm.

The C group was first obtained on July 8, with a leng-th of 7 cm. By September
it had become the dominant group and has remained so. During September, October
and Xovember it has continued to grow in length, increasing from 10-5 cm. (Septem-
ber G) to 13 cm. (November 24). The growth was not, however, as rapid as during
July and August.

6551 — 15A

I

CANADIAN FISHERIES EXPEDITION

ATLANTIC VVATEKS OF CANADA

REPORT OS THE COPEPODA OBTAINED IN THE GULF OF
ST. LAWRENCE AND ADJACENT WATERS, 1915.

BY

PROFESSOR ARTHUR WILLEY, D.Sc, F.R.S., F.R.S.C, etc.

Professor of Zoology^ McGill University, Montreal.

PART I.

The pelagic Copepoda are small Crustacea averaging less than five millimetres in
length, whose abundance in the sea is the measure of their importance as a direct
source of food-supply for the young of the commercial fishes. In addition, they are
pre-eminently the food of the herring which in its turn is preyed upon by larger fi.<5he8
such as the cod and halibut. Accordingly, the investigation of their distribution as
governed by depth, season, currents, salinity, and temperature, is generally recognized
as having an economic bearing, for fishes will necessarily assemble in places where
their food is plentiful. Much work has been devoted to this subject in recent years,
especially in European waters, the general purpose of such investigations being to
correlate the movements of these organisms with the seasonal migrations of fishes and
with the seasonal variations of currents. In the IS'aples monograph of the pelagic
Copepods (1892), the author. Dr. W. Giesbrecht, remarks that very little information
was at that time available for the northern part of the Pacific ocean and for that part
of the Atlantic ocean which lies between the 35th and 48th parallels of north latitude.
It is convenient to remember that cape Cod is situated a little above 42° 'N. In Cana-
dian waters there had been no quantitative study of the zooplankton up to the year
1915, but the gulf of Maine and the coastal waters between Nova Scotia and Chesa-
peake bay have quite recently been thoroughly explored during two seasons, the sum-
mers of 1912 and 1913, by the United States fisheries schooner Grampus, under the
direction of Mr. Henry B. Bigelow.

The investigation has to be conducted along two lines : systematic and hydrogra-
phical, which in this case is tantamount to saying qualitative and quantitative. The
object of the first method is to identify the species, in itself a matter of no little diffi-
culty, involving many microscopic examinations. The second method seeks to deter-
mine their relations to the physical and biological conditions of the local environment.
In 1901, Dr. W. ^[. Wheeler published a systematic report on the free-swimming
Copepods of the Woods Hole region. The delimitation of this region was interpreted
in a liberal sense so as to include not only Vineyard sound but also Plymouth harbour,
Mass., and that part of the Gulf Stream which lies 60 to 80 miles due south of Martha's

173

174

DEPARTMENT OF THE NAVAL SERVICE

Vineyard. The last two localities are within a day's journey of Woods Hole, Plymouth
harbour being- a boreal locality, whilst the Gulf Stream carries a tropical and subtro-
pical fauna. As the four localities covered by Wheeler are typical of their respective
districts, it may be desirable to tabulate his records for facility of reference and com-
parison. These records relate primarily to the fauna at or near the surface, a fact
which may partly account for the absence of such representative boreal species as
Calanus hyperboreus, Euchaeta norvegica, and Metridia longa, which frequent the
deeper strata, of water around 40 or 50 metres, although they sometimes ascend into the
surface layers. They are essentially open-water forms, and it is probable that Ply-
mouth harbour and Vineyard sound are too close to the land for them to find the
necessary conditions.

Table A.— Wheeler's Records (July 1899).

Gyninoplesi.

Woods Hole.

Vineyard Sd.
9 XX

Plymouth Hr.

Gulf Stream.

9 xx

9 1

d' 1

9 1

XX

7. Calocalanus pavo

9 XX
9 X

'■ X

X

XX

10. Centropages typicus . .

11. Centropages hamatus

X
X

XX

XX

" X

13. Teniora longicornis

14. Metridia lucen.s ( =M. hibernica)

15. Candacia armata ( =Candace pectinata)..

XX

9 1

"xx

X
X

' XX

XX(d^XX9l)

XX

XX

18. Anonialocera patersuni , . . . .

19. Pontellopsi? regali.-s ( = Monops regalis).. .

20. Acartia tonsa

21. Tortanus discaudatiis ( = Coryiuua buni-

X \

& XX

'"xx

X

Podoplea omitted

X means present.

XX means abundant.

Of the two divisions of the free-living Copepods, namely Gymnoplea or Calanoids
and Podoplea or Harpacticoids, the former is more directly concerned with the purpose
of the present investigation. Of all the species which have passed under review, the
one that is most widely distributed and most abundant in the fishery districts is Cala-
nus finmarcMcus, known to the more observant fishermen as " red feed " or " herring
feed ". It is part of our problem to deal with this and some other species, not only
in the full-grown condition but in such of the stages of early growth as are brought
up in the tow-net. Six stages in the postlarval development of C. finmarchicus have
been specified by Professor Gran (1902) who seems to have been the first to attempt
an analysis and interpretation of the mode of occurrence of this species in the Norwe-
gian North Sea, where its superabundance had been previously signalized by G. O.
Sars. Gran's six stages, adopted with slight inversion by Damas (1905), may be re-
garded as typical for the Calanoids as a whole, although in some cases the procedure
differs remarkably as regards the details of subdivision and fusion of the abdominal
segments Thus, at a certain stage, the young Met'^idia has a four-jointed urosome
(hind-body) in either sex; the adult female has a three-jointed urosome through fu-
sion of the first a?id second segments; the adult male has a five- jointed urosome through

CANADIAN FISHERIES EXPEDITION, 191Jrlo

175

subdivision of the earlier fourth segment. There is a similar sequence of segmenta-
tion in Tortanus. The development consists of three main periods : embryonic period
within the egg; nauplius or larval period comprising six stages; post-larval or copepodid
period comprising six stages, of which the sixth is the adult (see Lebour 1916).

Table B. — Copepodid Stages of Calanus (Damas 1905).

Stages.

Thoracic
segmetits.

Abdominal
segments.

Pairs of legs.

I

2

2

2 and

rudiments of third pair.

TI

3

2

•A

IP fourth j;air.

III

4

2

4

fifth

IV

5

3

0

V

0

4

5

VI /^

5
5

4
5

.0
5

At least two other spefies. nf siiinll f^ize. must bo ro"-arded as important ^mirres of
food for young fishes in the gulf of St. Lawrence, viz, Pseudo calanus elongatus which
attains a length of 1-5 mm., and Tortanus discaudatus (ahout 2 mm.). The former
abounds also in the Norwegian sea, the latter is a characteristic Laurentian species.
When these forms and others which are commonly associated with them, e. g. Temora
longicornis (1-5 mm.) and Centro pages haniatus (1-5 mm.), occur in such numbers as
to overshadow the larger forms, they give the plankton a distinctive character both as
to colour and size, the dominant tone after preservation in formalin being a dusky
grey, and the individual dimensions aggregating to give the aspect of a microcalanoid
plankton. A microcalanoid plankton may also be brought about by the predominance
of the young stages of larger species, especially those of C. finmarchieus. When the
individuals are larger and the dominaiut colour, before and after preservation, is red,
owing to the quantity of red oil in their bodies, the plankton wears a megacalanoid
aspect. Such a sample may be composed in varying proportions of Calanus finmar-
chieus ( 3 to 5 mm.) C. hyperhoreus (3 to 7 mm.) and Euchaeta norvegica (3 to 8 mm).
Intermingled with these we find sometimes the white Metvidia longa which according to
Farran (1910) is the "most typically Arctic copepod of whose distribution there is
any accurate knowledge" (quoted by Bigelow, 1915, p. 292). The four last-named
species are as a general rule limited to the waters north of Cape Cod but C. finmar-
chieus ranges to the south of Nantucket, and Euchaeta norvegica was taken from 50-0
fathoms in lat. 40° N., long. 69° 29' W. (Bigelow, 1915).

Giesbrecht tabulated the species of pelagic copepods under three leading regions:
species of the warm region (between 47° N. and 44° S.) ; species of the northern cold
region; species of the southern cold region. He showed that the copepod farmas on
opposite sides of the American continent are more nearly related than those of the
three hydrographical regions named above. Thus the main faunistic differences ap-
pear in following the distribution from the equator to the poles or from the poles to
the equator, not from the eastern to the western hemispheres.

Calanus finmarchieus is not only the commonest copepod in eastern Canadian
waters and in the North Atlantic coastwise waters generally, but it occurs more abun-
dantV" than any other form in the San Diego region where its daily vertical migrations
have been studied by C. O. Esterly (1911). According to O. O. Sars (1901) both
C. finmarchieus and C. hyperhoreus extend tbroiighout the Polar Sea from Greenland
in the west to Behring Strait in the east. He adds that the former species is equally
devoured by herring and mackerel and " in some cases, as stated by Prof. "Robert
Collett, forms almost the exclusive nourishment of one of our greatest whales, Balae-

^76 DEl'ARTMENT OF THE NAVAL SERVICE

noptera borealis. ' On account of the up-and-down movements referred to in the
preceding paragraph, it becomes important to note the time of day when the hauls are
made. The total quantity of Calanus present in the column of water filtered through
the vertical net at a given station is of more practical concern than the quantity at
any particular depth. Esterly found that the maximum abundaaice (" plurimum ")
at the surface occurred during evening twilight. The surface, in a quiet sea, is prac-
tically deserted during the daylight hours, the plurimum between 6 a.m. and 6 p.m.
being located at about 200 fathoms. J. I. Peck (1896) found in Buzzards bay that
from sunrise to sunset the copepods desert the surface almost completely. The fac-
tors which operate in causing this daily rhythm have been analysed in the case of
Lahidorera aestiva by G. H. Parker (1902). Other cases have been discussed by J.
Loeb (1894). At station 48 of the Michael Sai^s, between the Canary islands and the
Azores, on May 31, 1901, Dr. Hjort states that " the tow-net at 40 metres contained
a mass of red copepods, which were not observed at the surface during the daytime,
but suddenly appeared as soon as it grew dark soon after 6 p.m."

In addition to the diurnal there are seasonal migrations. Gran (1902) found off
the Norwegian coast from Romsdal to Lofoten, females swarming in April and May
over the coastal banks. In August and September great quantities of the young stages
(II to IV) are found at the surface. In winter Calanus descends into deep water.
Gran supposes that the autumnal juniors sink into deep water where they slowly com-
plete their growth and rise again to the surface as the spring adults which then spawn,
in Norwegian waters. On the other hand the first haul made by the " Princess " on
May 11, 1915, between Prince Edward Island and the Magdalen Islands contained
both adults and juniors amidst a swarm of Pseu do calanus (see table 1).

According to Giesbrecht's faunistic observations, the distribution of pelagic
copepods does not conform to the oceanic currents although these are factors in their
dispersal. Beyond a certain point the distribution of Calanus -finmarchicus does not
seem to be determined by ordinary physical factors. In the gulf of Maine this species
was taken by the Grampus in water at temperatures ranging from 42° to 76° F., but
was most abundant between 42° and 50° F. (5-5° to 10° C). The density of the water
in which it was living in swarms varied from 1024 to 1-027. It was wholly absent
in pure Gulf Stream water and in the very fresh water at the mouth of Chesapeake
Bay. Bigelow adds that none of the physical constants which were determined in his
exploration of 1913 will account for " the scarcity of Calanus in the waters south of
New York in July, for the subsurface salinities, temperatures, and densities of many
of those stations were well within the range occupied by the species in the gulf of
Maine. What the limiting factor is, is one of the numerous questions raised, but not
answered, hy our cruise." (Bigelow, op. cit. 1915, p. 290-291). That the Gulf Stream
is no barrier to C. -finmarchicus in the proper latitude, is shown by the records of
Acadia station 16, June 1, 1.45 a.m., where the surface copepod haul contained 82 per
cent of this species, the temperature exceeding 12° C, and the salinity 35 per thousand.

The factor which determines the limit of southern dispersion of C. -finmarchicus
is clearly neither a simple physical constant nor a single organic tropism. It can only
be explained at present in terms of endemicity, which includes the biological factors
of food-supply and propagation. The Calani which swarm in and about the gulf of
St, Lawrence have not been brought there by the Labrador current but are endemic in
the Canadian waters. This is shown not only by the presence of the different stages
but by the occasional capture of spawning females, taken in the act of extruding an
egg or before the latter has had time to become detached from the body of the parent.
This is not a frequent observation but was noted in several instances, viz.. Princess
stations 9 and 17; Acadia stations 3, 35, 65, 66, 88; No. S3 stations 13, 14, 25, 26.
Females with spermatophore were seen at Princess station 20; Acadia stations 66, 79,
85, 86, 87, 89 ; No. 3S stations 13, 25, 58, 59, 64.

The endemicity of C. finmarchicus in the gulf of St. Lawrence being thus proved,
it remains to consider its habit of assembling in swarms, in other words its gregarious

CAXADIAX Flf^HERIES EXPEDITIoy, lOl'rlo

177

habit. The records indicate that the Galanus inhaibiting these waters is part of one
vast, continuous community, whose southern frontier is not a straight parallel of lati-
tude but a scalloped border which changes with the seasons; but it is none the less a
definite boundary because the species holds together in virtue of the cohesion of the
individuals. The Calani, with their rich oily bodies, form a floating mass which does
not readily mix with the pure Atlantic water; the line of separation of the calanife-
rous water from the oceanic water is like a line of contact between fluids of different
viscosity which have a slight tendency to mix ; the degree of viscosity being influenced
by the presence of the copepod swarm.

Calanus finmarchicus is both euryhaline and eurythermal, i.e. it is independent of
ordinary diurnal and seasonal fluctuations of temperature and salinity. This fact is
brought out very clearly by the records of No. 33 station 23, which show a gradation
in percentages of this species entirely disconnected with the gradations in temperature
and salinity.

Table C. — Steam Trawler No. 33, station 23, June 25, 1915, between Anticosti and
Gaspe; 49° 31' K, 63° 58' W.; depth 855 metres.

Temperatures :

. +8-09°
. +8-0°
. +3-42°

Centigrade.
75m. .

. . — 0-71''

lOni

100 "

. . — 0-22°

20 " . . .

125 "

. . +0-3°

30 " . . .

. +2-21°

150 "

. . +1-3°

40 " .

. +1-38°
. +0-43"

250 "

. . +3-7°

50 " .

350 "

. . +4-56"'

60 "

. —0-12°

E OF COPEPOD

CONTEXT IX PLAXKTOX.

PERCEXTAG

Species.

Surface 5 mins.
10 CC.

100 .

Vertical 45— Om.
12 CC.

39
44

8

Closing: net

100— f.0m.

15 CC.

33

52

6

Closing net

340— I45ui.

90 CC.

Calanus finmarchicus

Calanus hyperboreus

Pseudocalanus elongatus

20

60

2

5

Eiichffita norvegfica

2

8
1

7

Scolecithrix minor

0

Metridia longa

<>

100

100

100

100

Salixi
. . 28*59

riES.

75m

. . . 32-51

10m

. . 28-93

100 "

. .. 32-84

20 " .

. . 30-78

150 "

. .. 33-48

30 "

. . 31-31

250 "

. .,. 34-22

50 "

.. 31-97

350 "

. . . 34-62

The tables (I-XII) accompanying this report display the distribution of the prin-
cipal species met with. It is not necessary to continue the tabulation of every station
from Acadia 57 to 90, and I will therefore deal with this portion of the exploration
somewhat more summarily.

Table D. — Percentage of C. finmarchicus of all ages at Acadia stations 57 to 67.

Stations

Percentages

57
3

58
50

59
51

90

fil

80

62
62

63
45

65

47

66
(17

67

28

178

DEPARTMENT OF THE NATAL SERVICE

At stations 68 and 69 the hauls were so scanty as to be negligible, though C. fin-
marchicus from stage III onwards was present at both. At station 74 the subsurface
haul was sparse and contained hardly any copepods; twenty-five were picked out, and
these included C. finmarchicus III (5), IV (3), and ? (1). Here we have an example
of a tongue of northern calaniferous water of salinity 33 per thousand bearing south-
wards over Atlantic water of salinity 35.

In the following table E the vertical hauls were made from 180-0 fathoms except
at station 76, where the haul was from 150-0 fathoms.

Table E. — Copepod content in the vertical net over the Atlantic slope south of Cabot

Strait, July 26-27.

Acadia Stations.

70

72

74

75
2"

76

3
27
10

79

7

19

5

30

V-VI

C. hj'perboreus III- V

2
3

50
X

C. tenuicoriiis . . .

X

Evicalanus elcngatus

2

1

10

2"

3

X

4

■ 2 '
2
5

X-

X

X

24

4

9

Clausocalanus arcuicornis .

1
1

2"

5
X
X

5

Pspudoealanus elongatus ....

Ae.tideus armatus . . ...

X

Gaidius tenuispinus

Undeuchaeta major

11 minor

l'

Euchirella rostrata

6

X

1

11 noivegica

Scolecithrix minor . . . .

13

14

25

21

5

I

1()
6

5

7

II ovata

11 bradvi

X
X

1
1
1

2 '
10

4

8

2

12
X

1
X

100

11 echinata

Centropages bradyi

Temora longicornis

7
X

8
X
33
X
X

10'

X

Metridia longa

75

15
10

12
1

Pleuiomauima abdominalis

11 rf)bufta

5

11 xi|)hia.s .

11 borfalis.

"2"

Heterorhabdus longicornis

1

1

Candacia armata

100

100

100

100

100

Acadia station 80, July 27, depth 168 metres, at the eastern end of St. Pierre
bank, is of interest as lying close to station 24 of June 2 (see table X). On the earlier
date there was a great paucity of copepods but stages II to V of C. finmarchicus were
observed. At the end of July the same early stages were present and, in addition, the
blue copepod, Anomalocera patersoni, had put in its summer appearance at the surface.

CAXADIW ri>iIIFTni:^ EXPEDITIOX, WH-Io

179

Table F. — Percentage of Copepod content in surface and vertical hauls at Acadia

station 80, July 27, 4 p.m.

S|)ecies.

Surface.

Vertical

: 145-0 metres.

C. fininarchiciis II ....

X

Ill

3
10
13

4

2
44
22

2

100

15

IV

V '

2.5
14

9

3

Pseudocalanus elongatu.s.

15

Centropages haiiiatus

25

Temora longieotnis ... .
Anomalocera patersoiii . . .

3

0

100

The next important station is Acadia 83, 20 miles south of St. Pierre island. This
station, in its depth (172 metres) and proximity to the south coast of Newfoundland
resembles Princess station 41, which was similarly situated with reference to the north
shore of the gulf of St. Lawrence (see table VI). The plankton sample in the vertical
haul (Acadia 83) consisted of about 85 c.c. of material, but tliis was highly gelatinous
and there were only some 1,500 copepods altogether. In the surface haul (15 minutes)
the net was weighted so as to sink it to 5 to 10 fathoms; the amount taken was about
350 c.c, with excessive numbers of Obelia medusae and young schizopods, and a
moderate infiltration of copepods. The plurality of C. finm^rchicus in this tow (65 per
cent) corresponds to its normal midnight plurimvun at the same depth, according to
Esterly's computations. The agreement is not always so close. At station 86, July
28, 11.10 a.m., the subsurface haul yielded 100 per cent of C. finmarchicus, of
which 72 per cent belonged to stege V; at this station the temperature fell rapidly
from 13"S° C. at the surface to 2'6° at 50 metres, and still further to -0*4° at 75 metres.
Perhaps this minimum temperature, in conjunction with the currents, acted tempora-
rily as a false bottom, obstructing the normal daylight descent to the deeper strata.
The effect of currents upon the vertical migrations of Calanus have been little invest-
igated. The area within which Esterly's collections were made was expressly chosen
on account of its freedom from tidal currents and storms.

Table G.— Acadia 83, July 2S, midnight (12.50 a.m.)

Species.

Surface.

C. finmarchicus III . . .

IV ...

V . . .

9 ...
Pseudocalanus elongatus.
Centropage.'* hamatus ...

Temora longicorKis

Anomalocera patersoni . .

2
27
35

1

10

100

Vertical : 160 0 metres.

16

34

20

3

X

20
6
1

100

Stations 85 to 87 cross the Laurentian Channel and may be compared with Princess
stations 45 to 47 (table VII) and AcaMa stations 25 and 26 and 34 and 35 (table X).

180

DEPARTMENT OF THE NATAL SERVICE

It will be seen that the comparison of the vertical hauls is chiefly demonstrative of
the relative constancy in the character of the Calanoid fauna in the Laurentian
Channel from June to August.

In order to obtain full value from these tables it is necessary to distinguish
between what may be called eurytropic species which are generally distributed through-
out the area covered by the several cruises, and stenotropic species whose distribution
is seemingly limited within a narrower range by physical factors of temperature,
salinity, and depth. Such eurytropic species are Calanus finmarchicus, Pseudocalanus
elongatus, Euchaeta norvegica, and Metridia longa. In consequence of their ready
toleration of slight changes in the temperature and saltness of the water these species
are not reliable indicators as regards the interaction of currents and the stratification
of the water. On the other hand the stenotropic species such as Calanus hyperboreu^,
Euchirella rostrata, Scolecithrix minor, Metridia lucens, and Heterorhahdus norvegicus,
are especially valuable as indicators. Thus the subjoined table shows that a greater
number of these stenotropic species occurs on the eastern side of Cabot strait in the
boreal oceanic water which is in the track of the inflowing Cape Eay current, than on
the western side in the line of the Cape Breton current which conveys water out of the
gulf of St. Lawrence. This agrees with the behaviour, in this region, of certain
species of Sagitta, as I am informed by Dr. A. G. Huntsman, who has made a most
intensive study of the distribution of the Chaetognaths and with whom I have discussed
the bearing of some of the data presented in this report concerning the Copepods.

Table H. — Vertical hauls in Acadia stations 85 to 87, July 28, 1915.

Laurentian Channel.

Across

Species.

C. hyperboreus

Calanus finmarchicus III.
IV .

V .
9 .
cf .

III.
TV

V .
9

Pseudocalanus elongatus .

Aetideus armatus

Gaidius tenuispinus

Kuchirella rostrata

ICuchaeta norvegica

Scolecithrix niinor

M ovata .......

Centropages haniatus

Metridia longa

II lucens

Heterorhahdus norvegicus.

270-0 metres.
85

1

25
15

2

5

Ifi

15

100

270-0 metres.
86

X
10
34
10
10
X

2
X
X

2
X

X

22

2

100

290-0 metres
87

3

10

2S

8

1

X

1

X

X

1

X
X
X
26
1
X
X
20
1

100

Acadia stations 88 and 89, on Misaine bank, both yielded Euthemisto plankton,
including an abundance of C. finmarchicus from stage III to spawning females, with
an excess of stage IV in all the hauls. On this bank at the beginning of June we
encountered an Aglantha plankton, whereas at the end of July there were no medusas
here. As regards the Calanus, the chief change to be noticed was an increase in the
number of adult females, 26 per cent in each of the surface hauls at stations 88 and
89. The latter station may be compared with station 79. Finally, at station 91 in the
Gut of Canso there was an Evadne plankton with a copepod admixture consisting of

OA^'ADIiy FISHIFJRIHS EX I'EDITIoy , 19I',-to

181

51 per cent Torianus, 25 per cent Temora, 15 per cent Pseudocalanus, and 0 per cent
Centropages. The temperature here fell from 12° C. at the surface to 11-45° C. ?.t 45
metres and the salinity was 29-14 per thousand at 20 metres.

Table J.— Data for Acadia station 89, Misaine Bank, 1-32 metres, July 28, 1915.

8.-35 p.m.

Si)ecies.

C. finmarchicus TIT

IV

V . . .

9

cf

C. hyperboreus III

IV

V

9

Pseudocalanus elongatus. .

Euchajta norvegica

Centropage* hainatus

Metridia longa

Anunialocera patertsoni ....
Tortanus discaudatu.s ...

Surface.

2(;
17

2

5
4

X
X

100

30 -Of.

1
44
18
10

3
15

X

O.T-0 f.

3
34

It;
«

X
4

20
1
1

12

X
2
1

100

100

In September, 1915, Dr. A. G. Huntsman made a short cruise in the Bay of
Fundy in the ss. Prince, belonging to the Biological Station at St. Andrews. The data
for the Copepods at the four stations are given in table XII. For the first time in the
course of these investigations we meet with the species Centropages typicus which
occurs regularly in the gulf of Maine and far to the southward of cape Cod, even
reaching the latitude of cape Charles (Bigelow, 1915, p. 293, and fig. 70, p. 294).

At Prince station 1, Dr. Huntsman observed a great stirring up of the water from
the bottom to the surface in consequence of the eddies caused by the tidal currents
surrounding the points of land. The presence en masse of C. finmarchicus at the
surface between 3 and 4 p.m. under a bright sun is unusual, and perhaps the deep-
seated turbulence of the water, with the resulting lack of stratification, was respoTi-
sible for it. It would be worth while to repeat the station, taking samples at intervals
through the twenty-four hours, in order to ascertain whether the diurnal migration of
Calanus is altogether inhibited. The effect of stratification of the water, so far as
temperature is concerned, is seen in an experiment by Dr. G. H. Parker (1902).
Female Lahidocera are negatively geotropic, and remain at the top at all temperatures
between 10° and 26° C. If the temperature is raised to 30° C. they become positively
geotropic and swim to the bottom. The lower half of a large glass tube was filled with
sea-water at 24° C. ; into the upper half sea-water at 30° C. was poured gently. A
female Lahidocera, introduced at the top swam rapidly downward, but stopped at the
plane of separation for the two temperatures.

Besides the diurnal and seasonal migrations of Calanus to which reference has
been made, there is another kind of translation which has been called ontogenetic
migration by Dr. Giesbrecht. Some pelagic copepods, as Clauso calanus, Pseudocalanus,
Eucha^ta, Eurytemora, carry their eggs in an ovisac attached to the genital segment,
but most species discharge their eggs directly into the sea. These eggs, according to
Giesbrecht's observations, have a somewhat higher specific gravity than the water and
consequently sink slowly; whilst they are sinking they accomplish their embryonic
development. As soon as the Nauplius larva hatches out of the egg, it ascends toward.s
the surface and towards the light, all copepod Xauplii being positively heliotropic.

182

DEPARTMENT OF THE yATAL SERVICE

The development of Calanus from the egg upwards was followed by C. Grobben
in 1881, whose memoir I have not had for reference during the preparation of tliis
report. The larval and copepodid stages have recently been described and figured by
Marie C. Lebour (1916). All the larval stages are so small that they pass through the
fine meshes of the silken tow-net, and this commonly happens with the first two cope-
podid stages as well. In order to obtain the earliest stages they must either be reared
under laboratory conditions or the finest procurable silk bolting cloth must be used for
making the tow-nets.

It is not knov^rii exactly when the ontogenetic migrations end and the diurnal
migrations begin. Esterly (1911) confines his enumerations to stages V and VI which
he considered together, rejecting the younger forms. Making allowance for the fact
that stage I rarely comes under observation, we may still unite stages I, II, III, and

IV as a superstage under the term juniores as employed by Gran, in order to compare
it with the superstage of which stage V is the adolescent and stage VI the adult form.
By grouping certain of the data contained in the tables in the manner indicated, a con-
trast appears between the distribution of the juniors and that of the two final stages,
the former being more bound up with the surface layers than the latter. For example,
at No. S3 station 17 there was a copious and typical microcalanoid plankton of stages II
and III, together with Pseudo calanus at the surface (see table VIII). The contrast
which is brought out in the subjoined table K is a partial illustration of the ontoge-
netic migrations of Calanus finmarchicus. If the closing net could have been used
more frequently, and if actual numbers were given instead of percentages, the diffe-
rences in the behaviour of the two superstages would have been rendered much more
manifest. Of course these ratios have no claim to exactness because so many inter-
acting factors disturb the simple relations, but they may serve to bring the problem
into relief.

There is reason to suppose that if stages V and VI were examined separately they
might also exhibit differential behaviour. Indications of inverse behaviour of stage

V and VI (?) are to be found amidst the data recorded in the tables. At Acadia
station 39 the surface ratio of V to VI was as 10:40; in the vertical haul from 25-0
metres as 15:24; in the vertical haul from 100-0 metres as 26:19. Again at No. 3S
station 23, the surface ratio of V to VI was as 0:90; in the vertical haul from 45-0
metres as 2:20; in the closing net from 100-60 metres as 5:23; in the closing net from
340-145 metres as 15 :2.

Table K. — Ratio of juniors (II-IV) to adults (V-VI) of C. finmarchicus in surface
and vertical hauls. Ac. =^ Acadia; Fs.^= Princess; 7. = Prince; ni = metres;
f = fathoms ; jun = juniores ; ad = adolescents and adults.

Station.

Depth.

Time.

Range of
vertical haul.

Ratio of

jvm. to ad.

in vertical

haul.

Ratio of
jim. to ad.
at surface.

Ac. 5

72ni

1 a.m.

60 - Om

44: 38

SO : 20

Ac. 14

2000m

12.50 p.m.

200 -Om

20: 56

nil

Ac. 16

,,

1.45 a.m.

.1

0: 13

12 : 70

Ac. 20

500in

10 p.m.

100 -Om

9 : 53

27 : 47

Ac. 28

,,

6 a.m.

100 - 25m

8: 41

51 : 36

Ac. 49

126m

3.40 p.m.

125 - Om

42 : 46

80: 7

Ac. 50 . .

151m

7.30 p.m.

145-Om

21: 47

40 : 40

Ac. 52

99m

1.45 a.m.

90 - Om

35: 51

CO : 32

Ps. 16

lOOf

1.15 p.m.
6 a.m.

100 -Om

24: 40
23 : 37

66 : 12

P*. 20

81 : 9

Ps. 21

,,

9.45 a.m.

„

26: 43

89 : 2

Ps. 39

284m

7.30 p.m.

1.30 -Om

»J: 15

50 : 5

Ps. 46

400m

6 a.m.

130 - Om

17: 74

47 : 53

P. 1

ISf

3.45 p.m.

18 -Of

6: 68

18: 72

P. 2

60f

4.30 p.m.

55-Of

3: 70

25 : 17

CAyADIAX FISHERIES EXPEDITION, 191. ',-15

183

PART II.

NOTES ON SPECIES.

1. Calanus finmarchicus. — There is a wide range of variation in the size of the
individuals during the several copepodid stages and this is often to be observed at one
and the same station. It is assumed that the transition from one stage- to another is
effected by a single exuviation. In one case I observed the new cuticle of stage V
forming beneath the old cuticle of stage IV, as shown most clearly by the coxal denti-
culation of the fifth foot. The denticulation on the inner margin of the basal joint
of the fifth foot occupies the whole of that margin in both stages V and VI; at stage
IV only the middle third of the coxal joint shows the marginal denticulation (text fig.
I). It is to be noted that the outer denticulation shown in the figure is much more
restricted in certain individuals.

Fie

1. — C. fimiuirchicus stage IV, length 32 mm.; fifth feet showing
transition to succeeding stage. Acadia station 9.

By employing biometrical methods. Gran (190.) found that within the limits of
the Norwegian North Sea, the individuals averaged larger in the north than in the
south. For example at stage III (synonymous with Gran's fourth stage) the maximum
length of the forebody in individuals captured in latitude 60° 43' N. was 1-25 mm.,
while in those taken in latitude 67° 41' N. the maximum length of forebody was 1-4S
mm. Gran also found in general that the stages are smaller in summer than in spring.
It is doubtful whether these biometrical results are applicable to other regions. To
render the history complete, it would be necessary to take stock of the frequency of
exuviations, and up to the present this has not been found practicable.

184

DEPARTMENT OF THE NAVAL SERVICE

The following tables give a few examples of range of size at stages IV, V, and VI.
The measurements were taken from the front of the head to the end of the caudal
fork.

Table L. — Range of C. finmarehicus IV.

Station.

Ac. 9
Ac. 28
Ac. 79

Ac. ><8
Ac. 89

(measurements in niillinietres.)

22; 32
20: 29

1 9 * to 20; small instars from 30-0 fathoms. In the haul from 180-0 fathoms some of

2 35 mm. were taken.
2-75; 3 0
30; large instars from 30-0 fathoms (compare Ac. 79).

Table M. — Range of C. finmarehicus V.

Ac. 5 ....

2-

Ac. 48

2-

Ac. 79 ...

2'

Ac. 80

4-

Ac. 85

3-

Ac. 86

2-

Ac. 88

2

Ac. 4.
Ac. 5.
Ac. 8
Ac. 79.

Ac. 85.
Ac. 86
Ac. 88
Ac. 89.

•9;

•65:

•25;

•9.

■6;

•65;

■75;

30;

45

2-5;

4 7;
45
4 0;

3-5

30; small instars as with stage IV at this station.
fai and oily.
4 1; 4-5

Table N. — Range of C. finmarehicus VI (?).

0; 4 0: 50

5; 365; 425

35; 3 75

9 with spermatophore ; 3 0 with spermatophore.

2 with sv>ermatophore ; 4 5

0 with spermatophore and turgid with pale pink oil.

65; 5 0

5

2; 5 5 with spermatophore.

Table O. — Range of C. finmarehicus VI (c?).

Ac. 86.

05; 50

CA\AniA\ risllKlilKS EXJ'EDITIOS, Wl.',-!',

185

The prroiitcst contrast in avorafrc size is exhibited between stations 79 and 89.
Table P accordinjirly gives the hydrofrraphieal data for these stations as worked out by
Mr. Paul Bjerkan.

TaijM': p. — Ilydrographical data for Acadia stations 79 and 89.

Metres.

44° 47' N.. 55" 13' W.
Station 7!*.

45° Ifi' N., 59' 4' W.
Station 89.

*

Salinity.

Temperature.

Salinity.

Temperature.

0

10

25

32 42
32-53
32-85
:;3 06
33-33

33 97

34-40

34 60
34-61
34 72

13 05
11-1
9-5
5-5
2-5
4 9

5-9
6-2
4 65
4 15

30-52

30 90
3192
32 13
32.13
32 24

13 95

50

9 1

75

100

0-75
015

125

0 15

0 05

150

200

300

400

2. Calanus hyperhoreus. This Arctic species is nearly as widely distributed in
our area as the preceding, but it is bound up with the deeper layers of water and in
that sense it is stenotropic, rarely appearing in surface hauls in these latitudes, ^[ore-
over it does not range so far south as C. finmarchicus. The Grampus found that, like
Euchaeta norvegica and Metridia longa, it was limited to the waters north of cape
Cod and was taken only at four out of twenty one stations in the gulf of Maine. At
Grampus sta.tion lOlCK) between cape Sable and Penobscot bay, opposite the mouth
of the Bay of Fundy, the vertical net from 90-0 fathoms contained 270 individuals of
C. hyperhoreus to 5400 C. finmarchicus, this being its plurinuim for the gulf of .Nfaine
(Bigelow, 1915, p. 293).

According to Damas and Koefoed (1905) C. hyperhoreus is the commonest form
at the surface in the Greenland sea. In Canadian waters there does not seem to be
any regularity in its occurrence at or near the surface and each case would probably
need to be accounted for by reference to local and temporary conditions. Its presence
to the extent of 5 per cent in the deep surface haul with weighted net at Acadia sta-
tion 85 and not at stations 86 and 87 is perhaps significant in view of what has been
stated regarding this station (see above, table H).

No male was observed in ai\v of the hauls. Sometimes there nuiy be a little
doubt regarding the identification of this species at stage IV with the three-jointed
urosome. The postcro-lateral angles of the forehody are not always so distinctly point-
ed as is usual. In such cases the do\ibt is at once removed by the examination of the'
fifth legs which although possessing coxal dentievdations in the subsequent stages, are,
unlike C. finmarchicns, devoid of them at stage IV in C. hyperhoreus.

3. Calanus vulgaris. — Other species of Calaniis Avere met with at station* in or
near the Gulf Stream. Of these tne most remarkable was C. vulgaris which is not
mentioned in " 'N'ordisches Plankton" (v. Breemen 1908). The female of this species
has the postero-lateral angles of the forebody produced on each side as a ventrally

6551—16

186

DEPARTMEM OF THE NATAL SERYICE

curved hook; in the male these edges are rounded, and the fifth feet have a peculiar
vermiform process on the left side which distinguishes it from all others. It occurred
at Acadia station 44 in the vertical haul, males and females, some of the latter having
a spermatophore attached to the urosome or hind-body.

C. tenuicornis was recorded at Acadia stations 17, 74, and 75; C. gracilis at 42,
44, and 75; C. minor at 44 (IS per cent at the surface), 56 (one male in closing net
from 210-140 fathoms), and 75 (males and females at the surface). C. minor is ano-
ther species not mentioned in " Nordisches Plankton " ; Wheeler observed numerous
females taken in Gulf Stream tow, July 25, 1899, the locality being 60 to 80 miles
south of Martha's Vineyard.

4. Eucalanus and Rhincalanus.- — All the species of these two genera which are
included in " Nordisches Plankton " were encountered in stations tangential to the
Gulf Stream; many of the individuals were immature, especially was this the case
with Rhincalanus. When attempting to differentiate the young stages of RTi. cornu-
tus and nasutus, the conspicuous feature of the forwardly produced head with its ros-
tral filaments is not an unfailing guide. Figs. 2 and 3 show the appearance of the
fifth feet in young females of cornutus and nasutus; figs. 4 and 5 show the fifth feet
in young males of cornutus of two sizes.

Fig. 2. — Rhincalmius ronaitua juv. $. Length 3 nun.
Fifth feet. Acadia station 44. 150-0 fathoms.

Fig. ?. — Rhincalanus natiutu.^ juv. 9 3 mm.
Fifth feet, one shown. Same station.

Fig 4. — Rhincalanvs cornutus juv, cf.
Fifth feet, hinder surface.

Fig. 5. — Rhinra/anus cornutus juv. cf. Fifth
feet, front surface of older stage.

rWADIW /7N// /:/.'//> I.XI'EDITIOW IDlfi-lo 187

5. Clausocalanus arcuiconiis. — Previously recorded by Wheeler from the Gulf
Stream. In the deep surface tow of Acadia station 74 there were very few copepods ;
out of a total of 25 counted, il were of this species, the others being C. finmarchicus
III (5), IV (3), 9 (1); C. minor (2); Scolecifhri.r minor (1), dance (1); Acartia
sp. (1).

6. Pseudocalanus elongatus. — The abundance of this small but rich and oily species
in the gulf of St. Lawrence is paralled by its frequency in the gulf of Maine. In the
intervening stretch of water between the entrance to Cabot strait and to the bay of
Fundy it does not occur in such great numbers. In the May plankton of the gulf of
St. Lawrence between Prince Edward island and the Magdalen islands, it constituted
on the average between eighty and ninety per cent of the copepod content. At several
other stations inside the gulf if reached to 20 per cent and upwards. In none of the
Acadia stations outside the gulf did it attain as much as 20 per cent, the nearest to
this quantity being 17 per cent at station 67; 15 per cent at SO and 90; 14 per cent at
36.- In all the females which have come under my observation in the preserved material
the ovisac was ruptured and the eggs appeared to be attached singly to the genital
segment, sometimes one at a time, frequently two, rarely three. Often the shreds of
the stalks of attachment are left behind after the egg has been liberated or torn away.
When two eggs are present they may be seen to be attached separately side by side.
Sometimes there will be one egg and the shrivelled stalk of another beside it. Sperma-
tophores are sometimes applied to one and the same female in great numbers. In the
example represented in fig. 6, I counted as many as twenty-four spermatophores.

Fig. 6. — Pscudocidnnu^ elomiatux 9, beset with spermatophores, ''Princess"
station 30, August 4th. 30-0 metres.

7. yEtideus armatus and Gaidius tenuispinus. — Neither of these species has been
recorded previously from eastern American waters, that is to say not by Wheeler nor
by Bigelow. They occurred together in Acadia station 75 in the vertical haul (180-0
fathoms or 325-0 metres) and again at station 87 (290-0 metres). Another noteworthy
record for Gaidius was at No. S3 station 23 in the closing net from 340-145 metres.
Besides this it was present in the vertical haul at Acadia station 46 (270-0 metres).

^tideus was not found at any station in the gulf of St. Lawrence. In addition
to the two Acadia stations mentioned above it occured also at stations 17 (200-0 m) ;
25 (120-0 m.) ; 44 (270-0 m.) ; 74 (325-0 m.) ; 79 (325-0 m.) ; 85 (270-0 m.) ; 8G
(290-0 m.).

8. Undeucha'ta major and minor. — These were not found by Wheeler but they are
mentioned by Bigelow (1915, p. 287). They are Gulf Stream species and minor is the
more frequent. They occurred together at Acadia sta^tions 46, 74, and 76. The.y are
found also in the San Diego region whence the male of U. m,ajor has been described
by C. O. Esterly (1905). The male of U. minor has remained hitherto unknown.
Several examples were taken in the Acadia hauls. The structure of the fifth feet of

6551— 16J

188

DEPARTMENT OF THE NAVAL SERVICE

the male of U. minor differs from that of U. major in the absence of the forceps mecha-
nism described by Esterly on the left foot and in some other respects. The chief
differences are displayed in table Q, supplemented by text-fig. 7 and 8. The postero-
lateral angles of the forebody are rounded; rostrum strongly deflexed; anterior
antennas exceed length of forebody.

%.^

Fig. 8. — Undenrha'ta minor cf
Right fifth foot from behind.
i?e = outer branch.

Fig. 7.— .Same. Left fifth foot.

Table Q. — Comparison of fifth feet (p5) of U ndeuchaeta major and minor 6.

Features.

Length

Right p5

Outer branch (Re)

Inner branch (Ri)

Left p5

Re

Re.

Undeuchaeta major cj'
(after Esterly. )

6 ■ 5mm

Biramous

Terminal joint produced into a long stylet.

Siniule .

Biramous

Terminal joint ending in a short style
which carries a pencil of long hairs near
its centre. Second joint bearing a toothed
process " which flares distally " ; " at the
base of this and on the second joint is
aniculated a process, which together
with the terminal joint of the ramus and
the toothed process forms a forceps. "

Vestigial

Undeuchaeta ■miiiord'
("Acadia " material.)

3 5 mm.

Biramous (fig. 8)

Terminal joint with spoon-shaped
e.vtremity.

.Simple.

Biramous (fig 7).

Terminal joint ending in a stylet
with a pencil of long hairs to-
gether with somedenticulations
near its centre, and a stout thorn
at its base. Second and third
joints incompletely separated.

Vestigial

CAXADIAX FISHERIES EX/'EDITIOX, 191^,-15

189

9. Euchirdla rostrata. — Several species of Euchirella occurred in the vicinity of
the Gulf Stream but the most widely distributed was this one. It has a distinctive
appearance with its portly crimson-tinted forebody and short urosoine. It was present
in varying quantity at twenty-four of the Acadia stations but never in the surface
hauls. At stations 85-87 which traversed the Laurentian channel between St. Pierre
and Mrsaine banks, its mode of occurrence is significant in view of what has been said
before. At each of these stations a vertical haul was taken from 30 fathoms to the
surface, and another from 150 or 160 fathoms to the surface. At station 85, Euchirella
rostrata occurred in both of the vertical hauls, two per cent from 30-0 fathoms, five per
cent from 150-0 fathoms; at stations 86 and 87 it was present only in the deeper hauls.
Its distribution within our area is shown on may (fig. 9). At station 54, where it appeasr
with the high plurality of 43 per cent, it should be mentioned that the plankton here
was very scanty, the vertical haul (150-0 fathoms) including only about 140 copepods
in all. Other species of Euchirella were taken as indicated on table XL

©-.©

ySy ®®©

®

(^^

(5)

@

w

Fig. 9.— Distribution of Euihirelhi ro.ttrata. The numbers indicate percentage of cojjepod content.

190

DEPARTMENT OF THE yAYAL SEIiVICE

10. Euchirella acadiana n. sp. — A few examples were taken of the female only of
tins species which I have not been able to fit in with any published description. The
occvirrence was at Acadia stations 41 (200-0 m., one) ; 44 (270-0 m., two) ; 56 (210-
140 fathoms, two). In the following diagnosis Giesbrecht's notation is employed:
Length 6.25 mm. (5 + 1.25) ; rostrum deflexed, pointed (fig. 10) ; genital segment sym-
metrical except for a low oblique brown chitinous ridge on the left side seen from
above near the hinder margin ; postero-lateral angles of f orebody broadly rounded.

Fig. \0— Euchirella acadiana. Profile of head sliowing frontal
organ and rostrum, after removal of right antenna.

Fig. 11.— Same. Proximal joints of right anterior antenna from inner aspect.

Anterior antennae (fig. 11) of normal length, reaching to about the middle of the
urosome.

C.WADI.W FlsnERIi:S KXPEDITIOy. nil ',-15

191

Posterior antennae (fig. 12) with three very long feathery setae at the end of
Re 7; B 1 with plumose Si (as in messviensis) ; B 2 with one Si (as in messinemi'i) ;
Re 1 and 2 incompletely divided, with a crest and spur at inner distal margin of Re 1
(as in curticauda) ; Ri about four-fifths the length of Re 1 and 2; Ri 2 bearing 15
seta\ of which there are six in a row on Le, 7 in a row on Li, the innermost being the
shortest, and in addition a very short Sp on Li near the point where it is continuous
with Le, and a somewhat longer Sp on Le.

^t^

Fig. 12. — Same. Posterior antenna, hinder surface.
The two posterior set* on Ri 2 may be noted.

192

DEPARTMENT OF THE NAVAL SERVICE

Maxilla (fig. 13) : Le 1 with 8 setae (as in messinensis) , the fifth seta about three-
fourths the length of its neighbours; Le 2 small, without seta (as in rostrata) ; Li 1,
hinder surface glabrous (as in rostrata), in the typical group 11-14 there are only
three seta? (as in messinensis) ; Li 2, with 4 setae, Sp 1 and 2 equal, long and stout, Sa
1 much shorter, Sa 2 slender but nearly as long as the Sp; Li 3 with fringe of long
hairs along the length of its anterior surface, at its end which is exactly on a level
with the end of Li 2 there are only two set«e, a distal long and stout seta and near it
a more proximal shorter seta; B 2, setse as in rostrata, surface ciliation as in messi-
nensis: Ri with 5 seta? of which four are subequal and the first, situated at the inner
angle on the iX)sterior surface, is short and slender like the two proximal setae of B 2 ;
Re with eleven setae as in messinensis.

^^.,

Fig. 13. Same. Maxilla, anterior surface. Sette omitted
from Li 1 and Re. Li 2 is partly concealed by Li 'S
whose fringe of hair.s passes over it. S 1 to S 5 are the
five seta? of Ri ; SI is seen with difficulty from this
side, but is very distinct from the hinder aspect.

CANADIAN FISHERIHS EXPEDITION, 191Jrl5

193

Anterior maxillipede (fig. 14) : Distinctive are the close-set fringes of spine-like
hairs on the posterior surface of L 1 to L 4; otherwise as in rostrata; the deep outer
emargination of B 1, a generic character, forms a right angle with the succeeding
portion of the margin which is nearly straight.

Fig. 14. Same, .interior maxillipede
hinder surface, setie omitted.

Posterior maxillipede (fig. 15) : the single seta of the first or proximal group (or
•' lobe ") on B 1 is placed as in Giesbrecht's figure of Chiridius poppei; L 2 with two
setae, one long, one short ; L 3 with three setae (two long, one short) ; L 4 with three
setae, two long, one short; a short longitudinal series of points on anterior surface
of B 2 near its proximal end ; the first seta of B 2 lies very slightly distad of the centre
of the inner margin.

Fig. 15.— Same. Portion of [wsterior maxillipede.

194 DEPARTMENT OF THE yATAL SERVICE

Fourth legs: basal joints with the characters shown in fig. 16.

Fig. 16. Same. Basal joints of left fourth leg.

11. Euchaeta norvegica. — As mentioned this is a eurytropic species occurring in
surface and vertical hauls both inside the Gulf of St. Lawrence and outside. It was
found in different stages corresponding to those detailed for C.finmarchicus and hyper-
horeus. Ovigerous females with single large ovisac full of blue eggs were found,
notably at Acadia station 48 on July 23, at No. 33 station 57 (Bay of Islands) on
August 9, and at Prince station 3 (Bay of Fundy) on September 15. Immature males
were as common as immature females, but the adult males were very rarely captured.
At Acadia station 11 (70-Om.) on May 30 one was found carrying a spermatophore ;
another at station 70 on July 26. The youngest captured was stage II with three pairs
of swimming legs and two-jointed urosome, first noted in No. 33 station 26 on June 26
in the subsurface haul (30-15 metres, towed for 20 minutes).

12. Scolecithrix cuneifrons n. sp. — Of the species of Scolecithrix met with, the
commonest was minor, next to that dame, and then ovata. The appendages of danw,
for a certain length of time after preservation in formalin, have a delicate mauve tint
which enables the species to be recognized amidst a multitude of other Copepods. Sc.
ovata is characterized by the oval fifth legs of the female; in many specimens they
are not to be found.

There were two other species, only one of which I am describing here since it
appears on table XI. I had at first identified it with securifrons but the structure of
the fifth legs of the male seems to differentiate it from that species.

Description of 8c. cuneifrons: Acadia station 46, 150-0 fathoms. Length of
female, 4-5 mm.; of male 4-8 mm.; high frontal crest and acuminate postero-lateral
angles as in securifrons. but in cuneifrons there is an acumination in the male as well
as in the female (fig. 17).

CAN A UI Ay FISHERIES EXPEDITION, IdUflo

195

Fig. 17. Scolecithrix cuneifrons.

A. Frontal profile of female of 4 '5 mm.

B. Frontal profile of female of 3G mm.

C Postero-lateral angle and genital segment 9.
D. Postero-lateral acumination of cf .

Rostrum produced, bluutly bifid at extremity; anterior antennae as long as body,
23-jointed in ?, 18-jointed in 6; mouth-parts not aborted in (S. Posterior antennae:
Re one and a half times the length of Ri ; B 1 with short plumose seta ; B 2 with two
setae, one long, one short ; Re 1 and 2 distinct. Re 2 twice as long as Re 1, Re 2 seven-
eighths the length of Re 7, Re 1 and 2 one and a third times the length of Re 7, Re 2
with one distal slender seta. Re 3, 4, 5, and 6 each with a long plumose seta. Re 7
with a long proximal seta inserted at the proximal fifth of the joint and three long
terminal plumose setae; Ri 1 with slender distal seta which is about twice the length
of Ri 2, distal outer convexity of Ri 1 fringed with cilia, Ri 2 with 8 setae on Li and
six on Le, outer convex margin of Le fringed with stiff curved cilia. Maxilla: Li 1
with crowded setae, thirteen counted, Li 2 with two setae, Li 3 with three equal setse;
Le 1 with nine setae; Re with eight setse; Ri with seven setae; B 2 with five setae. In
Ri and B 2 the number of setae given includes in each case one anterior seta.

196

DEPARTMENT OF THE XAVAL SERVICE

Anterior maxillipede (fig. 18) : B 2 with four setse of which the largest is not arti-
culated with the joint, another is transformed into a vermiform sensorium; Ri with
seven setse transformed into vermiform sensoria.

Posterior maxillipede: B 1 and B 2 subequal in length but B 1 much broader,
B 2 longer than Ri : B 1 sets : 1 + 2 + 1 + 3, a fringe of long haii-s at distal end ;
B 2 with a fringe of stiff hairs or cilia running along the whole length of the joint
near the inner margin, longer towards the proximal end; B 2 setfe: S 1 proximad of
middle of joint longer than S 2, S 3 longer than S 2, S 4 shortest, S 5 longest.

Fig. 18. — Same. Distal portion of anterior maxillipede.
First foot (fig. 19) : Re 1 and Re 2 with Se of equal length.

Fig. 19.— Same. Fir&t foot anterior surface.

CANADI.W llslir.RIES i:\ I'KIUTIOS , tOl'rl'j

t97

Second foot : B 1 has an acuiniiiatioii ou the outer margin like that on the third
foot but standing closer into the border, convex inner margin below the Si with long
cilia. Ri does not reach distal margin of Re 2; spiniiles on posterior surface of Ri 2:
2 + 2 + 2, the largest is the outer one of the proximal couple, the smallest is the
inner one of the «ame couple. The spinules on the posterior surface of Re are: on
Re 2 a transverse row of seven distal spinules continued proximad on the inner side
by three longitudinally placed spinules, the whole forming a continuous arc; spinules
on Re 3, two arcuate rows, namely: a distal arc of small unequal spinules, the two
lowest of the arch being level with the bases of Se 2 and Si 3 ; a proximal arc between
the bases of Se 1 and Si 2, the three inner spinules much larger than the rest.

Third foot (fig. 20 A aJid B) : the character of B 1 and the spinulation of the rami
are shown sufficiently in the figures; several minimal spinules at level of Si 2 on i)os-
terior surface of Re 3. otherwise no perceptible spinulation on that joint.

Fig.' 20 Same. Third foot.
A. Anterior surface, including B 1. B. Posterior surface, including Re 3.

198

DEPARTMENT OF THE NAVAL SERTICE

Fourth foot (fig. 21): B 1 with plumose seta; Ri extends beyond distal margin
of Ee 2, nearly reaching base of Si 1 of Re 3 ; Ri 2 two-thirds as long as Ri 3 ; Re 2
with outer margin ciliate ; Re 3 with outer margin, below the proximal Se, ciliate.

Fig. 21. Same. Portion of fourth foot, anterior surface.

Fifth foot of female (fig. 22): two-jointed ending in a curved seta tiiid a small
spine, as in securifrons.

Fig. 22. Same. Fifth pair of appendages of female

CAyADIAX FISHERIES EXPEDITIOX, lOl'rlo

199

Fifth appendages of male (fig. 23 A and B) : Left foot biramous, right foot unira-
mous with a process on B 2 which might represent a rudimentary endopoditic process
as described by Giesbrecht ior J^colecithrix viftata; left Re and Ri two-jointed.

Fig. 23.— Same. Fifth appendages of male

A. Left foot; second joint of Re broke oflF
and drawn separately, showing cushion
of points.

B. Right foot.

200

DEPARTMENT OF THE NAVAL SERVICE

The submature female of this species, 3.6 mm. in length, with the adult segmen-
tation but not having attained the full size and maturity, differs in several points from
the full-grown female. The genital segment (fig. 24) has a proximal protuberance in
place of the distal process (compare fig. 17 C) and does not possess the serrations at
the posterior lateral margin. In the full-grown form the second abdominal segment
has a fringe of shorter spinules at the lower margin. In the submature individual
while the fifth feet have the typical formation, the postero-lateral angle of the fore-
body is bluntly rounded instead of acuminate.

Fig. 24. — Same. Part of forebody and the urosome of a submature female.

13. Centropages hamatus. — This is a typical member of the microcalanoid plankton
whose distribution is to a large extent parallel with that of Tortanus discaudatus but
on the average it does not reach so near the shore line and extends further out to sea,
that is to say, over greater depths. This may be gathered in a general way from the
tables and it will suifice here to mention a typical example of a copious and clean,
gray-toned microcalanoid plankton, namely, the Souris Tortanus plankton exemplified
in No. 33 station 7. In addition to the proceeds of this station, Dr. Huntsman on
several occasions procured samples from canoes and motor boat«, thus establishing the
character of the Souris summer copepod plankton. Figure 25 shows the urosome of a
submature female with the adult urosome forming within the adolescent cuticle. It
was taken at the surface at Acadia station 62 on July 25.

Fig. 25. — Centropages hamatus Urosome of adolescent
female, shortly before an exuviation,

CANADIAN FISHERIES EXPEDITION, 1911,-15

201

SESSIONAL PAPER No. 38b

Centropages hradyi Wheeler was taken in Acadia stations adjoining the Gulf
Stream in the vertical hauls, viz., at 41, 42 ; in deep surface haul and vertical haul at
75. C. typicus was taken by Dr. Huntsman in the Bay of Fundy at Prince stations
2, 3 and 4.

14. Temora stylifera. — WTiereas Temora longicornis is as widely distributed as is
Centropages hamatus, Temora stylifera occurred in some numbers only at Acadia
station 44. Most of the animals were females in the adolescent stage which differs so
remarkably from the adult form that I was for some time in doubt as to their identifi-
cation. The lateral ang-les of the head are drawn out into two free processes like those
of trilobites (fig. 26). Unfortunately I have not had access to the original description
of the species by Claus, but the processes are not mentioned in the works of reference
which I have consulted as they do not occur in the full-grown stage. Otherwise the
structure of the appendages is typical. An adult male, 1-75 mm. had no prolongations
of the lorica.

Fig. 26. Temora s{i////cni. Dorsal view of
adolescent female to show the lateral pro-
cesses of the head ; anterior antennae
omitted. JiCngth 15 mm. Furcal sette
broken.

6551—17

202

DEPARTMENT OF THE NATAL SERVICE

15. Metridia longa and lucens.- — The mutual relations of these two species in their
distribution may be gathered from the tables. The former species ranges far and wide
in the Gulf of St. Lawrence having been taken in deep water in the Gaspe channel at
No. 33 station 23. In the Bay of Islands at No. 33 station 57 a typical Metridia longa
plankton was obtained. On the other hand Metridia lucens does not seem to penetrate
so deeply into the gulf of St. Lawrence being only recorded at two stations, namely,
at No. 33 station 69 (3 per cent) and Princess station 45 (5 per cent). It was also
taken by Dr. Huntsman at Prince stations 1, 2, and 3. Its distribution at represen-
tative stations is shown on the map (fig. 27). It was generally taken in vertical hauls,
rarely at or near the surface. It was taken regularly by the Grampus in the gulf of
Maine, while M. longa only occurred sparsely. Bigelow states that M. longa was not
found in the gulf of Maine in the 1912 cruise, and its discovery in the 1913 cruise was
the first record for American waters.

Fig. 27. Distribution of Metridia luvcns.

CANADIAX FISHERIES KXPEDITIoy, 191'rlo

203

16. Lahidocera aestiva Wheeler. — The capture of this species, which is very abun-
dant in the summer at Woods Hole, at Princess station 28 is worthy of special mention.
It is ^ven as a generic character of Lahidocera that there is no rostral lens, while the
dorsal lenses are larger in the male than in the female. In the material examined by
me the male measures 2mm. in length, the female 2- 5mm. The dorsal lenses of the
male are larger than those of the female and are contiguous; but in addition to the
dorsal lenses a rostral lens is present and clearly seen in ventral view. It will be a
simple matter to control this identification by re-examination of examples at Woods
Hole.

Fig. 28. — Labidoccra aestiva, female. Ventral view of head from a compressed
preparation show insr dorsal and rostral lenses. Freeh *nd. "Princess"
station 28, 20-0 metres, August 3, 191 o.

6551— 17i

2 04 DEPARTMENT OF THE NAVAL SERVICE

REFERENCES.

1. H. B. Big-elow, 1914 — Explorations in the Gulf of Maine, July and August, 1912, by the

United States Fisheries Schooner Grampus. Oceanography and notes on the Plank-
ton. Bull. Mus. Comp. Zool. Harvard, Vol. 58. No. 2.

2. H. B. Bigelow, 1915 — Exploration of the coast water between Nova Scotia and Chesapeake

Bay, July and August, 1913, by the United States Fisheries Schooner Grampus.
Oceanography and Plankton.

3. P. J. van Breemen, 190'8 — Copepoden. Nordisches Plankton IV. No. 8.

4. D. Damas, 1905 — Notes biologiques sur les Cop6(podes de la mer Norvegienne. C. P. I. E. M.

Publications de Circonstance No. 22, Copenhagen.

5. Damas and Koefoed, 1905 — Le Plancton de la mer de Groenland. Due d'Orleans' Cro'siere

oceanographique, Brussels, 1905. Quoted from J. Hjort, q.v.

6. C. O. Esterly, 190-5 — The pelagic Copepoda of the San Diego region. Univ. California Public.

Zool. Vol. 2, No. 4.

7. C. O. Esiterly, 1906 — Additions to the Copepod Fauna of the San Diego region. Ibid. Vol.

3, No. 5.

8. C. O. Esterly, 1911 — Diurnal migrations of Calanus flnmarchicus' in the San Diego region

during 1909. Internat. Rev. d. ges. Hydrobiol. u. Hydrographie, Band IV, pp. 140-151.

9. W. Giesbrecht, 1892 — Die Copepoden des Golfes von Neapel. F. Fl. Neapel, Vol. 19.

10. W. Giesbrecht, 1895 — Die pelagischen Copepoden. Reports on the dredging operations off

the east coast of Central America, etc. Bull. Mus. Comp. Zool. Harvard, Vol. 25, No.
12.

11. W. Giesbrecht and O. Schmeil, 1898 — Copepoda I Gymnoplea. Das Tierreich, Berlin.

eries and Marine Invest. Vol. II, No. 5, see pp. 56-65.

12. H. H. Gran., 1902 — Das Plankton des Norwegischen Nordmeeres. Rep. Norwegian Fisheries

and Marine Invest., Vol. II, No. 5, see pp. 56-65.

13. J. Hjort, 1912 — Murray and Hjort: The Depths of the Ocean. London (Macmillan), 1912.

14. M. V. Lebour, 1916 — Stages in the Life History of Calanus flnmarchicus (Gunnerus),

experimentally reared by Mr. L. R. Crawshay in the Plymouth Laboratory. Journ.
Mar. Biol. Assoc. Vol. XI, No. 1, pp. 1-17.

15. J. Loeb, 1894 — The influence of light on the periodical depth migrations of pelagic animals.

Bull. U.S. Fish Comm.' Vol. 13, Washington, 1894, pp. 65-68.

16. G. H. Parker, 1902 — ^The reactions of Copepods to various stimuli and the bearing of this

on daily depth migrations. Ibid, Vol. 21, Washington, 1902, pp. 103-123.

17. J. I. Peck, 1896 — The sources of marine food. Ibid, Vol. 15, Washington, 1896, pp. 351-368.

18. G. O. Sars, 1901 — Crustacea of Norway Vol. IV. Copepoda Calanoida. (Bergen

Museum).

19. G. O. Sars, 1912 — List of Crustacea from selected stations. Murray and Hjort: Depths

of the Ocean, London, 1912, pp. 654-656.

20. W. M. Wheeler, 1901 — The free-swimming Copepods of the Woods Hole region. Bull.

U.S. Fish Comm., Vol. XIX, Washington, 1901, pp 157-192.

CANADIiy FISHERIES EXPEDITION, W1J,-15

205

1

Abundant phytoplank-
tun. Taken at 9 a.m.

Abundant phytoplank-
ton. Taken at 3.20 i).m.

Taken at noon. No
cope]):xls at surface.

Taken at 5 p.m.

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35m;iesE.N.E. ofNorth

Pt., I'.E.I.
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stone Island.
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11. V.
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9. VI.

Station .

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206

DEPARTMENT OF THE NAVAL SERVICE

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CANADIAX FISHERIES EX I'EDITIOS', lOl.'flo

207

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208

DEPARTMENT OF THE NAVAL SERVICE

Remarks.

Ctenophores and fish eggs.

Sagilta and Amphipods.

Red Calanoid plankton.

Euch.-Bta III.

C. finmarchicusIIIchangingtoIV

C. hyperboreus 9 unique.

Scanty.

Euchita III and IV.

Ceratiuni and fisli eggs.

Microcalanoid planlcton.

C. finmarchicus I present.

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6551—18

218

DEPARTMENT OF THE NATAL SERVICE

Table XI — Acadia-

Station.

Date.
1915.

Depth.
Metres.

Haul.
Metres.

Time.

h- 1
3

u

i

C
D

O

8
11
28
30
19

7
10

4

4

20

10

10

6

a

5
10

3
21
20

+

>

c
c
u:

2
a

O

31

28
55
30
25
36
48
40

2

33
9

io

GO
32
30
15
17
17
50
32
57
38

10

+

E

c
=e

O

17
21
14
20
13
10
15
26
2
10

4

64

24

4§

28
41
i.2
34
14
40
13
30

6

1

cS

■■B

o

32

18

3

7

3

40

24

19

30

5

3

1

5
10

i4
1
6

12

5
6
2
18
9
6
3

c

B

S

!«

O

12
3

6
4

1
1

8

+
1
1

1
3

+

'2
3
2

£
1

2.
>■.

H

18

7
12

"1

8

4

'3
i5
8
5
'2
4
5

0

■V

>

J

>!

X

i

+
3

!5

+
+

'0

+
■i

c

i8

5

+

05

>

10

•

2
£

0

'2
5

+

be

B

3

0

1

+

5

B

2

+
+

14

20

+
+

+

'b

5
u

E
re
cS
0

+

+
+

2
1

_S
n

■r

+

2
9
4
2
2

i

1

B

2

+

B
_C

B
0

tc
3

37
37
38
38
38
39
39
39
40
40

*41

*41

41

**42

42

+43
44
44
+t45
45
45
46
46
47
47

148
48
49
49
50
50
51
51
52
52
53
53
54
54
+J55

21 VII

22 VII

23 VII

24 VII

62

62

170

170

170

li5

95

95

134

134

360

360

360

1000

1000

1000

1000

1000

1000

1000

1000

1000

1000

140

140

248

248

126

126

151

151

131

131

99

99

95

95

1000

1000

1000

1000

0
CO-0

0
100-0
150-0

0

25-0

100 0

0
125-0

0
100-0
200-0

0
200-0

0

0
270-0

0

90-0

270-0

0
270-0

0
125-0

0
230-0

0
125-0

0
145-0

0
125-55

0
90-0

0
90-0

0
270-0

5 p.m.

8 p.m.

11 p.m.

2a.m.
5.30 a.m.

9 a.m.

11.45 a.m.
3 p.m.

8.15 p.m.

1 a.m.

6.30 a.m.

11 a.m.

3.40 p.m.

7.30 p. m,

10.30 p.m.

1.45 a.m.

4.45 a.m.

7.40 a.m.

10.30 a.m.
2.20 p.m.

+

56

375-0

* Very scanty, copepod.s nil. ** Very scanty. fVery scant}' ; Phronima and Euthemisto : no

copepods. tt fhronima plankton ; no copepods. J Nil. JJ Very scanty at all depthts.

CA^'A^)IA^' fihhehiks Kxi'i.itirios, lui'i-i'i

219

stations 37-56— July, 1915.

o
a

*
o

s

_o

CO

+

«

2
IE

o

9
10

+
43

+

+

+

ce
<

+
2

Sb

>

c
c

J
C

+
1

3

3

12
32

8

+
+

4

a

i

15

o

£

•r
.c

'S

0,
0

+
+

is

+

-2
5

+

1
5

+

s
S

a

JZ
m

<L

be

a
s

c

+
+

'7
2
11

+

1

re
u

0

+

o
■c

6

1

5

Z
S

i

"c

3i

H

a.

1

c8

C

75

s

+

IS

9

'tla

>

0

c

2

•5
jz

u

£

41
ft

><

£

S .

a 0

3 ,-

ci s

1^

0

3

3

B
0

c
0
£

1

g
"cj

i

S

a
ee

"C

73

c

c3
'«

08

u
n

0

<

S

.2
•5

to

3
C

1

+

0

T3

i

S

s

100
100

100

20

3
10

+

3
5
3

1

2

48

65

+
+

100

KH)

100

100

100

+

100

100

-1-

'27'

5

+

28

+

"4'
10

"i

+

"i

+

100

7
3
5
4

9

+

10
2

+

8
8
3
15

25

+

34

5

2

i'

1

'6'

1

+

56'
75
27
21
1
13

100
100

100

100

2

100

50

100

13

100

-1-

2

100

100

100

10
3

26

13
14
12

8
9

"i
31'

+

lOo

+

100

100
100

"5'

ino

100
UK)

100

220

DEPARTMENT OF TEE NAVAu SERVICE

Locality.

a

i

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rt "

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mo

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:- -H

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Tp W5 CC ■— C^ -^ ■ "* 1-1

5 snoiqoJBuiug snuujuo

:o c-1 -f — c^i • -ir ic I- xi

• y^ snoiqoai;uiug shutjjbq

y-i O r- |2 '5 ■ T IC ^1 s

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!!+!!!!!'

c^ ri ro •^ -f" in

s

-a-
©

CO

in

K

Surface.

5-10
Vertical .
Surface.

55-0

Surface.

8-10

100- 0

3- 6

18- 0

V s:.

^3.

© o

CO 00 ■» ~ 1 O O O 00 cc

Date
1915.

yMyMy,'yMy:A'^,

•^-f-»<rf<»»>i~iO«lrtlO

Station .

^^

^ C>5 <M ?C CC CO -T

■>*■

CANADIAN FISHERIES EXPEDITION, 1914-15.

The Hydrodynamics of Canadian
Atlantic Waters

BY

W. J. Sandstrom.

G551— 18a

TABLE OF CONTENTS

Paoe.

Preface :i-'l

Chap. 1. Geographical condition of the area ofi investigation 222

" 2. The hydrographical observations 22."^

" 3. Dynamic importance of the isosteric surfaces 228

" 4. Forces derived from the distribution of density 229

" 5. Stability of the water in the Newfoundland area 2.'i2

" 6. Influence of the wind upon the movement of sea-water 233

" 7. Influence of the earth's rotation upon the movement of sea-water. . . . 239

" 8. Influence of melting ice upon the movement of sea-water 245

" 9. Influence of friction upon the movement of sea-water 253

" 10. On the cause and the effects of ocean currents 255

" 11. Bjerkne^' circulation theory 2(J3

" 12. Solenoids in the Canadian Atlantic area 2<)7

" 13. Influence of the earth's rotation upon circulation 272

" 14. Influence of friction upon circulation 275

" 15. The acceleration of circulation 278

" 16. On the topography of the sea's surface, on the pressure and energy in

the sea 285

" 17. Summary 288

FIGURES AND PLATES.

Fig. 1. Map showing the dimension of the area investigated 223

" 2. The rotation of the Foucault's i>endulum plane on the Newfoundland

area 224

" 3. The rotation of the Xewfoundland area owing to the rotation of the

earth 22G

" 4. Wind currents in homogeneous water 228

" 5. Water layers in stable juxtaposition 228

" 6. Wind currents in stable water layers 228

" 7. Archimedean forces in stable strata 230

" 8. Movement occasioned by the forces shown in fig. 7 230

" 9. Diagram of the stability of the sea-water 232

" 10. Stable sea-water in equilibrivmi 233

" 11. Influence of the wind on stable sea-water 233

" 12. Water layers jibing in a high wind 234

" 13. Strong circulation in surface layer after jibing 234

" 14. State of sea-water after a storm 235

" 15. Experiment on the action of wind upon water in strata 235

" 16. Wind, temperature and movement in the southern part of the Baltic,

1/8, 1907 236

" 17. Wind, 15°-isotJierm and movement between Africa and S. America,

lat. 20°S 23S

" 18. Experiment illustrating current opposed to the wind on weather shore.. 236

" 19. Wind and wind currents in Gullmarfjord 237

'' 20. Current opposed to the wind on weather shore and lee 238

" 21. Surface current on the approach of a storm 23>

" 22. Distribution of density by cyclonic rotation of surface water 239

" 23. Screwing movement of surface water in cyclonic circulation 240

" 24. Movement of the water in the Sargasso sea 241

" 25. Screwing movement in a deep water current 242

" 26. Vertical air blast against surface of water in layers (tank at rest) .... 242
6551— ISia iii

iv TABLE OF CONTENTS

Page.

Fig. 27. Vertical air blast against surface of water in layers (tank rotating). . 243

" 28. Movement of the surface water in the Newfoundland area 244

" 29. Ice melting experiment 245

" 30. The melting of the ice 246

" 31. Distribution of salinity near the ice 248

" 32. Distribution of temperature near the ice _. . 248

" 33. Movement of water near the ice 249

" 34. Movement of water in the tank by ice melting 250

" 35. Distribution of the temperature by ice melting over a warm and salt

bottom layer 250

" 36. Movement of the water by ice melting in Gullmarfjord 251

" 37. Distribution of the temperature by ice melting in Gullmarfjord . . . . 252

" 38. Frictional force as indicated by the movement of the water 253

" 39. Diagram of velocity for a current by constant frictional resistance. . . . 254

" 40. Diagram of velocity for a surface current in calm weather and with

wind in same and the opposite direction 255

" 41. Cyclonic and anticyclonic currents produced by i)hysical change of the

water and by wind 256

" 42. Current from centre of production to centre of consumption 258

" 43. Movement of surface water in the Gulf Stream 258

" 44. Experiment illustrating circulation of the Gulf Stream 260

" 45. Influence of the wind upon the Gulf Stream 262

" 46. Bjerknes' diagram of the Archimedean forces 264

" 47. Solenoids between two water layers 264

" 48. Method of calculating the circulation in a sea current 265

" 49. Relation between solenoids and circulation 266

" 50. Isobars, isosters and solenoids in section IX 268

" 51. Solenoids in section IX 269

" 52. Amount of solenoids in section IX 271

" 53. Cyclonic circulation produced by the earth's rotation 272

" 54. Density and calculated velocity by offshore wind 278

" 55. Alteration ol] circulation acceleration 280

" 56. Submarine seiches occasioned by brief but violent gales 281

" 57. Oscillation of surface water 282

" 58. Direction of wind on 7/1, 1902, 9 p.m 283

" 59. Courses of wind on 7/1, 1902, 9 p.m 284

" 60. Circulation of the water in a transverse section of a current with cold

bottom water . 294

Plate I. Depths and hydrographical stations.

" II. Distribution of salinity. Spring, 1915.

" III. Distribution of salinity. Summer, 1915.

" TV. Distribution of temperature. Spring, 1915.

" Y. Distribution of temperature. Summer, 1915.

" VI. Distribution of specific volume. Spring, 1915.

" VII. Distribution of specific volume. Summer, 1915.

" VIII. Course o:^ isosters. Spring, 1915.

" XI. Course of isosters. Summer, 1915.

" X. Depth in metres of the isosteric surfaces. Spring, 1915.

" XI. Depth in metres of the isosteric surfaces. Summer, 1915.

" XII. Stability conditions of the Canadian Atlantic waters. Spring, 1915.

" XIII. Stability conditions of the Canadian Atlantic waters. Summer, 1915.

* XIV. Calculated velocities. Spring, 1915.

" XV. Calculated velocities. Summer, 1915.

THE HYDRODYNAMICS OF CANADIAN ATLANTIC

WATERS.

By J. W. Saxdstrom.
PREFACE.

Dr. Johan Iljort has entrusted me with the task of working up, in dynamic form
the results, of his hydrographical observations in the Canadian Athmtic waters. It
has been a great pleasure to me to undertake this work, as the observations, being
restricted to the upper strata of d5^lamic interest, and with the consequent limitation
in point of time, may be regarded as almost simultaneous; a feature of great import-
ance when dealing dynamically with the material. In addition to this, the area in
question is a most interesting one, presenting as it does a well-defined mass of
water acted upon by various and very considerable forces. In the course of the work,
valuable assistance has been afforded me by Mr. Paul Bjerkan's clear and concise
report of the expedition, Mr. Thorolf Rasmussen's excellent draughtmanship in the
elaboration of my rough pencil sketches, and Mr. W. J. A. Worster's translation
into English of my hastily compiled Swedish text. Without such co-operation, I
should scarcely have been able, in the scanty leisure left me by my official duties
and other obligations, to carry through the work at all; as it is, I hope that the
following pages may prove of some value, not only in discussion of the observations
in question, but also as contributing to the general comprehension of various
phenomena in the oceans of the world, in regard to which the conditions prevailing
in Canadian waters may be taken as affording analogy and illustration.

The " Survey of Tides and Currents in Canadian Waters," " The Currents in
the Gulf of St. Lawrence," and other publications kindly placed at my disposal by
Dr. Hjort, contain a mass of most valuable observations as to the movement of the
surface water in the gulf of St. Lawrence and adjacent waters.* A good indication
of the reliability of these observations is the fact that the popular but erroneous
theory of currents due to the action of wind, has here been abandoned. Instead of
this, we frequently find the correct observation that a current may arise, or increase
in force, some time before the appearance of a storm, such currents being as a rule
in a direction contrary to that of the coming wind. These phenomena, which are
explained by Bjerknes' circulation theory, give the observer generally an impression
that the water in the sea has a very remarkable and unexpected tendency to opposi-
tion against the forces striving to act upon it. The usual primitive conception as
to the laws which govern movement in liquids will not sirffice to explain such para-
doxical phenomena; it will be necessary to introduce new ideas, for the proper com-
prehension of which a considerable amount of mathematical knowledge will
frequently be required. On the other hand, it seemed to me of the highest importance
that the interested obseners in the Canadian Atlantic waters, and also in other parts
of the globe, should be able to familiarize themselves with these new principles, and
I have therefore endeavoured to get around the mathematical difficulties as far as
possible by extensive use of graphical illustrations, and by reference to well-known

* This series of valuable publications, embraces the results of many years' investigations
by Dr. W. Bell Dawson. D.Sc, F.RS.C, etc., head of the Dominion Tidal Survey, Ottawa, and
the staff under his direction.

222 DEPARTMENT OF THE XiVAL SERVICE

principles, in particular the Archimedean, which, in addition to being generally
understood, is simple and easily comprehensible in itself. I have, moreover, in order
to exemplify these principles, given reports of some experiments and also taken some
examples from the atmosphere when the hydrographical facts were insufficient.
Such limitation and simplification will, I trust, render these complicated yet
interesting theories accessible to a wider circle among those at all occupied with
marine phenomena.

The following pages open with a short report of Dr. Hjort's observations. These
naturally form the foundation upon which the whole of the subsequent dis-
cussion is based, as without knowledge of the conditions prevailing down in deep
water, it would be impossible to explain the phenomena which take place in the sea,
or even those apparent at the surface. The next sections will be devoted to my own
explanation of the questions concerned, in the simplified manner above mentioned,
leading up to an exposition of that part of Bjerknes' theory which directly applies to
conditions in the sea, further the changes into different kinds of the energy in the
sea and as summary an application of the laws found on the Canadian Atlantic
waters.

j:._geogeaphical conditioxs of the area of investigation.

I have before me a chart of the area in question, with numerous soundings, pre-
senting a detailed survey of the bathymetrical conditions. In order to obtain some idea
as to the dimensions of this marine basin, I draw out on the chart a system of parallel
lines, at intervals of 100 km., each line being again divided up into lengths of 100 km.,
(fig. 1). At the points thus marked off, I draw short lines indicating the depth, these
latter being perpendicular to the original system of parallels. By inserting the inter-
mediate depths according to the chart, vertical sections are obtained for every 100 km.
throughout the entire area. (Fig. 1.)

In marking off the depths, I endeavoured at first to adhere to the same scale as
that for the horizontal dimensions of the chart, but found the lines thus drawn too
short; I therefore multiplied them by ten, so that the lines for vertical dimension were
drawn to a scale ten times that of the horizontal. Even this, however, proved insuffi-
cient, and I found it necessary to magnify them 100 times in order to render them
reasonably legible.

In order, then, to obtain a correct idea as to the bathymetrical conditions within
the area investigated, we must imagine the depth lines reduced to one-hundredth of
the length shown in the figure. It now becomes apparent, that the vertical dimensions
are extremely knall in comparison with the horizontal. Drawn to the scale of the
chart, the greatest depth within the area woiild appear about equal to the thickness of
the paper on which it is printed. And if we should attempt to draw a vertical section
across the area, maintaining the correct proportion between depth and horizontal
extent, the result would be merely a line and this moreover in the shallower portion;;,
so fine as to be invisible to the eye.

If we were to make an exact model, on a reduced scale, of the area in question, it
would appear, at a first glance, to be perfectly flat. And on attempting to " fill " it
with water to a level answering to that of the sea, as a first step to experimental repro-
duction of the actual hydrographical phenomena, even this would be found practically
impossible, owing to the surface tension of the water. So thin a layer would either
wet the entire surface of the model or leave dry patches here and there without regard
to level. To obtain a basin suitable for the purposes of such experiment, the depth
would have to be magnified 1,000 times in proportion to the horizontal extent.

This disproportion between the vertical and horizontal dimensions should be con-
stantly borne in mind throughout the discussion of tlx sections dealt with in the fol-
lowing pages.

CANADIA^i FIfiHERIES EXPEDITION, 19J'i-l.J

223

224

DEPARTMENT OF THE NAY A J. HERYICE

Let us now make a mental experiment. We imagine, in the centre of the area of
investigation, e.g., on Cape Breton island, a high tower, built in the form of a gasholder.
To the centre of the roof, on the inner side, is fastened a fine but strong cord, at the
lower end of which, reaching nearly to the floor, a heavy weight is attached, forming a
pendulum. This pendulum is set in motion, and the plane in which it moves marked
off by a line drawn on the floor at certain intervals of time. It will then be found
that the plane in question revolves in the same direction as the hands of a watch
placed with the dial upwards. The rate of progress is about 11° per hour; i.e., the
plane of the pendulum would make one complete revolution in thirty-three hours,
supposing that the pendulum itself could be kept in motion for that time. Fig. 2
shows the course traversed by the plane in the space of twenty-four hours.

Fig. 2. — Tlie rotation of the iiendulinn
plane during 24 hours by a Foiuault's
pendulum exi>erinient on the New-
foundland area.

The cause of this phenomenon is as follows : The plane in which the pendulum
oscillates does not, as a matter of fact, revolve at all; what does revolve is Cape Breton
island and its surroundings, which turns with the earth's rotation about its axis. Sim-
ilarly, in our pendulum experiment, it is the tower which turns, at the rate of one
complete revolution in thirty-three hours, while the true plane of oscillation for the
pendulum remains unchanged. The revolution of this plane is thus only apparent,
and, correctly interpreted, means simply that the whole of the Canadian Atlantic area
is rotating, at what, in consideration of its enormous extent, must be regarded as a
very high rate of speed. The direction of this rotary movement is counter-clockwise,
i.e., the reverse of the movement made by the hands of a watch dial upwards; the rate
of speed

<o — Wo sm (f.

(1)

where ip is the latitude, Wq the angular velocity of the earth about its axis, w the
angular velocity of the surface of the earth at a latitude amounting for the area in
question to about three-quarters of a revolution in the course of the twenty-four hours.
Fig. 3 shows the position of the Canadian Atlantic area at a moment of starting,
after 6 hours and after 12 hours. At the moment of starting, we have drawn in the
conventional- manner N upwards, S downwards, with E on the right and W to the left.
After the lapse of six hours, these points of the compass will have shifted 65°, and
after the lapse of 12 hours, 130°, to the left. The Gaspe and Cape North currents,
which in the first illustration are seen moving towards the right, continue their move-
ment in this direction, despite the rotation of the substratum, thus curving rouji'd
Gaspe and Cape Breton island, as shown in the two following diagrams. On the other

CAXADIAX FISHERIES EXI'h'niTloX, lOI'rlo 225

hand, the current passing cape Kay commences towards the left, and in this direction,
owing to its inertia, it still continues, although the substratum is under rotatorj' move-
ment. Consequently, the current is seen to curve round the southwestern ix)int of
Newfoundland. This point is, however, so sharp, that the current cannot turn there,
to enter St. George's bay, but does not become perceptible until reaching the Bay of
Islands, and is then very distinctly apparent along the coast as far as Rich point.
Owing to the same cause, the Labrador current turns up into the fjords along the
whole of the east and southeast coasts of Newfoundland; hence the numerous ship-
wrecks in those waters. " Seamen should be on their guard against an indraught
among the Fago and Wadham islands into Sir Charles Hamilton's sound, Bonavista,

Trinity and Conception hays On the southeast coast, so many wrecks have occurred,

especially near cape Pine and St. Shot's cove, that the compass has been considered
to be subject here to local disturbance, but special examination has shown that this is
not the case, and that these disasters were mainly attributable to the effect of the
currents". (Sailing directions of the North American coast).

The rotation of the earth about its axis, then, gives to the ocean currents an
apparent tendency to turn off towards the right. As a matter of fact, the actual
tendency of the water is owing to its inertia' most emphatically towards direct forward
progress, but the continual rotation of the ocean basins and the coasts towards the left
(Fig. 3) makes the currents appear as persistently veering off to the right.

The reader should, throughout the following pages, continually bear in mind the
three points which have been emphasized above, viz., the insignificance of the vertical
dimension in the sea when compared with the horizontal, the continual rotary move-
ment of the basins towards the left (in the northern hemisphere) due to the earth's
rotation, and the obstinacy with which sea water opposes the action of external forces.

2. THE IIYDROGRAPHICAL OBSERVATIONS.

Plate I shows the position of the hydrographical stations. Sections I-IX, carried
out during the time between May 29 and June 26, 1915, give the hydrographical con-
ditions in spring, and sections X-XX, Jvily 21 to August 12, 1915, the same for sum-
mer. In addition, the separate stations, 1, 2, 3, and 4 in the gulf of St. Lawrence
belong to the spring cruise, and. stations 27, 28, 54, 58, and 59 in the same water to the
summer cruise.

Plate I shows likewise the bathymetrical conditions in the area investigated. With
regard to those, the remarks about Fig. 1 should be borne in mind, i.e., that the depths
are extremely slight in proportion to the horizontal distances. The chart presents a
fairly detailed picture of the bottom contour. The position of the banks, and their
extent, should particularly be noted, as also the regular contour of the Laurentian
channel leading in from the Atlantic deep to the gulf of St. Lawrence, and the chan-
nels between the banks and the coast.

The following plates are based on the hydrographical material i:)laced at my dis-
posal by Dr. Hjort.

Plates II and III show- the distribution of salinity as noted on spring and summer
cruises, respectively. A water layer of less than 30 per cent salinity flows out at the
siirface between the Gaspe coast and Anticosti, filling the southern portion of the gulf
of St. Lawrence, rounding cape North, Breton island, and proceeding thence south
and soutliAvest along the coast of Nova Scotia. Throughout its course, this layer is
continually absorbing water from the subjacent strata, whereby its salinity is increased,
until it ceases to exist as a coastal water. A surface layer of like character is also
found during spring in the northern portion of the gulf of St. Lawrence. With
increasing depth, and farther out to sea, the salinity is augmented in the manner indi-

226

DEPARTMENT OF THE NAVAL iiERVWB

Fig. 3. — The rotation of the Newfoundland area owing
to the rotation of the earth.

CAyADIAX FhSlIERIKS EX l'i:i )irin\. nil',-1.-, 227

catcd by plates II and III. >iot imtil the very outermi>st statidiis arc reached, how-
ever, do we encounter true Ath\ntic water of over 35 per cent salinity.

Plates IV and V show the distribution of temperature during the spring and
summer cruises. I'articularly noteworthy is the enormous intermediate layer of tem-
peratures below zero, which fills the whole of the gulf of St. Lawrence and a great part
of the coastal zones outside. During the spring, it also extends far down towards the
coast of Nova Scotia, but in summer the extent is somewhat less. Both above and
below this intermediate cold layer, the temperature increases. During summer, we find a
surface layer of comparatively lii,y-h temperature. At the outermost stations, the warm
Atlantic water is found.

The distribution of temperature and salinity, and the hydrographical conditions
generally, have been thoroughly dealt with by Mr. Paul Bjerkan,! to whose work on
the subject the reader is referred.

Given salinity and temperature, we can, by means of IMartin Knudsen's tables,
calculate cr^ and the specific volume; i.e., the volume in ccm. of a gramme of water.
If we designate the specific gi'avity of the sea-water by p and the specific volume by
V then we have

v^-^ (2)

P

If, for instance, o=28,10, then |0=1- 02816, whence, according to formula (2), v=
0-97261. As, however, nearly all the values for specific volume within our area of
investigation begin with 0-97, we may simplify matters by omitting this figure and
multiplying the remainder by 10^, whereby the specific volumes appear as whole num-
bers of three figures, and are thus far easier to manipulate. This is the more permis-
sible, since we shall in the following only have occasion to reckon with differences of
specific volume. Instead of v = 0-97261, then, we write vi = 261, the equation indicat"
ing that a gramme of the water in question represents a cubic capacity of 0-97261 ccm.

In table 1, the first column shows the depths in metres at the points where water
samples were taken, and the second column vi for the samples in question, calculated
according to the method indicated above, from the last column in Bjerkan's hydro-
graphical table. Plates VI and VII show the distribution of specific volume within
the area investigated. It is greatest at the surface, decreasing downwards, which
naturally means, that the lightest water lies uppermost, and the heaviest at the bottom.
In the Gaspe current and the southern portion of the gulf of St. Lawrence, the specific
volume is particularly great. The lines for like values of specific volume, the so-called
isosteres, exhibit a far more horizontal and regular course than the isohalines and
isotlierms. In the upper water layers, the specific volume decreases rapidly with increas-
ing depth, especially during summer, when the surface water is warmed by the sun ; in
the lower strata, however, the decrease takes place far more slowly.

Plates VIII and IX present a more detailed view of the course of these isosteres.
For the deeper water layers, they have been drawn for each tenth unit of v, in the upper
strata for each fiftieth. For general convenience of reading the isostere vi = 500 is
here prominently shown.

1 Paul Bjerkan : Results of the hydrographical observations made in the Canadian Atlantic
waters by Dr. Johan Hjort during the spring and summer of 1915.

228

DEPARTMEtsTT OF TEE iA^AT'A/ SERVICE

3. DYNAMIC IMPORTANCE OF THE ISOSTERIC SURFACES.

The stable position of the strata in these waters is in many respects characteristic
of the movement occasioned therein. In order to make this clear, we may take a simple
example. Fig". 4, let us say, represents a sea tasin filled with homogeneous water, i.e.
in which no isosteric surfaces occur, subjected at the surface to the action of wind
blowing in the direction of the larger arrow. The water will then commence to circu-
late in the manner indicated by the small arrows, the current thus induced increas-
ing continually as long as the wind lasts. Take, then, fig. 5 as representing a basin
containing diiferent water layers in stable equilibrium, for the sake of convenience,
we may presume that only three water layers of different specific gravity are repre-
sented. The layers themselves will then all be devoid of isosteric surfaces, but in the
dividing surfaces between the layers, a large number of isosteres will be found. When
not subjected to the action of external forces, the three different kinds of water will

Wipd-

Fig. 4. — Wind currents in liuniogeiuoua wattr.

arrange themselves in horizontal strata, the specific gravity increasing with the depth.
Should, now, a wind arise, it will act upon the surface of the uppermost and lightest
layer, the water of which this is composed being forced along in the direction of the
wind. This layer will then become wedge-shaped, as shown in fig. 6, its water at the
same time circulating in the manner indicated in fig. 4. Owing to the friction thus
caused a certain amount of the movement in this surface layer will be communicated
to the layer immediately beneath, which in its turn begins to circulate, but in the
opposite direction, the combined movement exactly corresponding to that of two cog-
wheels working together. Finally, the bottom layer will be similarly set in motion by
the one above it, and will commence to cii-eulate in the same direction as the surface
layer, albeit at a slower rate.

Fig. 5. — Water layers in stable juxtaposition.

Fig. C. — Wind currents m stable water layers.

CANADIAN FISHERIES EXPEDITION, WlJf-lo 229

The above simple example will serve to give an idea as to the complicated move-
ment caused by the wind in water layers of stable relative position. The system of
strata and movement of the water shown in figs. 5 and 6 are of very frequent occurrence
in the sea; in some places, however, the density increases more continuously with the
depth, and isosteric surfaces are then found in all parts of the water. Such waters
may be regarded as consisting of an infinite number of infinitely thin strata. The
movement of the water here is highly restricted, which gives rise to very peculiar dyna-
mic phenomena. The water assumes a remarkable power of resistance against the
action of external forces, and when these cease to operate, it returns to its original
position.

Let us now endeavour to ascertain the cause of this. Taking any one of the
isosteric sections in either of plates VIII and IX, we imagine a water sample from
one of the isosteric surfaces transferred to a greater depth. It will here be lighter
than its surroundings, and will therefore, according to the Archimedean principle,
j'ise until it once more reaches the isosteric surface from which it was taken, and
there it will remain. In the same way, if a sample of water be shifted to a point
above that whence it was taken, it will be heavier than its surroundings, and will
sink until it reaches the isosteric surface corresponding to its own specific gravity.
It is otherwise, however, when a sample of water is moved along the isosteric surface.
Here its specific gravity remains equal to that of its surroundings, and no force
arises which would occasion its return to the original position. Thus we see that
the water can only move along the isosteric surfaces, and not transversely through
them. In other words, the scope of movement of the water, instead of being tri-
dimensional, is restricted to the two dimensions.

The constant validity of this principle throughout the whole of our present area
of investigation is most clearly shown by the existence, and extraordinary permanence,
of the cold water layer. It is at once evident that no vertical convection can take
place through this layer, the movement of the water being strictly confined to the
horizontal.

It is therefore of particular importance to ascertain at what depths the water par-
ticles composing one and the same isosteric surface are to be found. For the sake of
convenience we may here content ourselves with examining the isosteres i;i=400, 500,
600, etc. These depths may easily be found, by interpolation, from the Vi column in
table ], and are here included in table 2. In this table, B indicates that the isosteric
surface in question touches the bottom, and * that it cuts the surface of the sea before
reaching the hydrographical station concerned. Plates X and XI show some of these
figures for depth at their proper position within the area of investigation. Here
also, lines are drawn to indicate the intersection of the isosteric surfaces with the
surface of the sea. This figure shows at a glance why it is that the surface water,
daring the cold season, keeps to the coastal zone, but is able during the warmer
months to move farther out. Another point immediately evident is' the very high
degree in which the heating of the surface water by the sun's rays contributes to its
freedom of movement.

4. FOECES DEEIYED FEOM THE DISTEIBUTION OF DEN"SITY.

The Archimedean principle itself teaches us a great deal as to the forces in the
sea which are derived from the distribution of density. When the water at a certain
point :s specifically lighter than its surroundings, it tends to rise, while if heavier,
it will tend to sink. Let A, in the section fig. 7, represent light, and B, heavy water, the
two strata being separated by an oblique surface. The deeper portion of the light
layer A is then surrounded by heavier water, and is specifically lighter than its sur-
roundings, according to the Archimedean principle, therefore, it wiU be driven

230 DEPARTMENT OF THE NAVAL .SERVICl!

upwards, as indicated by the arrow in the figure. The highest portion of the layer
B is heavier than its surroundings, and has thus a tendency to downward movement
liere similarly indicated. Thus we see, that according to the Archimedean principle,
the lower portion of the dividing surface will be raised, and the upper lowered; in
otlier words, the dividing surface will become horizontal.

Fig. 7 — Archimedean forces in stable strata.

Fig. S. — Movement occasioned by the forces
shown in Fig. 7.

It is easy to understand what movements will be thus occasioned in the water
itself. The water will be forced from the thicker to the thinner portion of the
stratum, until finally a layer of uniform thickness is produced. We have thus
horizontal movements, proceeding in a direction from the thicker towards the
thinner portions of the lasers, so tliat the forces indicated in fig. 7 occasion the move-
ments shown in fig. 8.

This simple argument is, as we shall subsequently see, of fundamental imi^ort-
ance for the comprehension of the actual conditions in the sea, and will also heli>
us to explain an interesting effect of the wind. The surface water in fig. 6 has been
transformed into a wedge-shaped stratum by the action of the wind. When the wind
drops, this layer will, according to the Archimedean principle, tend to resume its
normal uniform thickness, the water being forced from the thicker towards the
thinner portion of the layer; i.e., in a direction contrary tx) that of the wind pre-
viously acting upon it. Thus the action of wind upon normally stable layers of water
occasions, upon its cessation, a movement in the surface layer contrary to the former
direction of the wind.

It may also happen that water is continually introduced into some portion of
a stratum. The thickness of the stratum will then be greater at this point than in
the surrounding portions, giving rise to Archimedean forces which drive the water
from the point of inflow horizontally towards the farther limits of the stratum. In
the tropics, great masses of water are heated by the rays of the sun. Such water
becomes specifically lighter, and passes over into the surface layer, which in the
tropics amounts to 600 metres depth, whereas at Spitsbergen it is only 200 metres.
Thus the Archimedean forces drive the water from the tropics towards Spit$:bergen.
And the resulting current is that known as the Gulf Stream.

From the foregoing, also, it will be understood that the Gaspe current, the water
of which is formed in the mouth of the St. Lawrence river, becomes continually
shallower as it (proceeds. To the west of the Gaspe peninsula it must be deeper than

VANADIAK FISHERIES EXPEDITWS, 191.'rl^> ^31

to the east of there, and still shallower in the Cabot strait. It is this variation in
depths which gives the current its forward movement.

The difference of level in the separating surfaces in the sea is of the same impor-
tance to the movement of sea-water as the varying level of the surface of a river to
the movement of the latter. The force impelling a sea current may be calculated
from the slope of the separating surface in the same manner in which the force of
a river's current is calculated from the slope of its surface water. In the case of
marine currents, however, we have to take into consideration the difference in density
pi — Pi> between the two layers, instead of reckoning merely with the full density of
the sea-water. The same thing should, as a matter of fact, be done in the case of
a river ; the density of the air above the water, however, is so slight as to be negligible
in comparison with that of the river water. Save for this, the methods of calcula-
tion would be exactly identical for both river and sea currents.

We can also, if preferred, reduce the difference in level of the separating sur-
faces correspondingly, multiplying them. by

Pi~P^

P

and then reckon with the entire

mass of the sea current.

This reduction of density naturally tends to diminish considerably the effect
of a marine current ; this is, however, great enough, owing to the enormous mass of
water involved in the movement. Thus for instance, the difference in level of the
separating surface in the course of the Gulf stream, amounting to 400 m., is reduced
to only 1-5 m. But as the Gulf stream carries 25,000,000 tons of sea-water per
second, this slight waterfall yet supplies a force equivalent to 500,000,000 horse-power,
which is sufficient to overcome the friction and keep the current in motion.

From measurements of the depth and velocity of the Gaspe and Cabot currents we
may calculate, in a similar way, the force and amount of energy which serves to main-
tain the movement of this current, so important for the hydrographical conditions in
the Gulf of St. Lawrence.

Obviously, this simple quantitative method is enormously valuable in determining
the causes, features and effects of a marine current.

The propulsion of the currents is thus the most important work performed by the
Archimedean forces in the sea. They have, however, also another function of import-
ance here. When an external force acts in the water, the latter is at first moved in the
direction whither that force is tending, vide fig. 6. This gives rise to Archimedean
forces tending in the opposite direction. As long as this displacement of the water
continues the strength of the opposing Archimedean forces continually increases.
When this has reached a power equal to that of the external force in operation, a state
of equilibrium is attained, and the movement of the water ceases. From the Archi-
medean forces, therefore, we can ascertain in this case at once the direction and
magnitude of the external force.

We can thus, from the form of the isosteric surfaces, discover what forces are
acting upon the water. Plates X and XI, showing the shape of the isosteric surfaces
in the Canadian Atlantic waters during the spring and summer of 1915, thus give us
at the same time an idea of the forces then acting upon the water there. We see that
the isosteric surfaces slope from out to sea inwards towards Cabot strait, reaching
there a considerable depth. This shows, that some force is at work, tending in towards
the gulf of St. Lawrence. It is the deflecting force of the earth's rotation, which
presses the Labrador current to the right, in towards Cabot strait, and causes the
isosteric surfaces to slope as we have seen. This obliquity, however, again gives rise
to Archimedean forces in the water, pressing outwards, and opposing the inflow of the
Labrador current into the o'ulf. And from the magnitude of the Archimedean forces
here we can, as will In-^ ^- be seen, ascertain the velocity of the Labrador current in this

232

DEPARTMENT OF THE ^t^AYAL SERVICE

region. Doubtless, also, similar forces of resistance oppose the inflow of the Labrador
current into Belle Isle strait.

Within the gulf of St. Lawrence, it is noticeable that the isosteric surfaces as a
rule lie deeper in the peripheral portions than in the central part. This suggests the
action of a force tending radially outward from the centre; evidently the centrifugal
force occasioned by the cyclonic circulation of the water in the gulf.

Many other interesting details may be seen from Plates X and XL In section
IV, for instance, the TOO isosteric surface lies deeper in the middle of the sound than
off the Gaspe coast, evidently a quite abnormal situation, due to some strong external
force, which, at the time when the section was taken, must have been operating in a
direction from the Gaspe coast to Anticosti, probably a strong south west wind.

5. STABILITY OF THE WATER IN THE NEWFOUNDLAND AEEA.

The stability of sea-water may conveniently be characterized by noting the num-
ber of isosteric surfaces per 10 metres of depth. The third column in table 1 shows
this value for all depth intervals in the present investigations.

It is of great importance to find a method of graphic illustration for this feature,
indicating the condition of the water. After various attempts, I have selected the
following as being most convenient. The state of a vertical in the sea is represented
by a vertical line, the thickness of which is drawn proportionate to the stability. Plates
XII and XIII illustrate, in this manner, the stability of the sea-water at the hydro-
graphical stations with which we are here concerned.

By this method, homogeneous water is indicated by an infinitely narrow vertical,
see fig. 9 a, and water of constant stability, i.e. the specific volume of which decreases
in linear proportion to the depth, by a line of equal thickness throughout, (fig. 9 b).
In the sea, owing to rainfall and the inflow of fresh water, as also to the heating of
the surface water by the sun, the decrease of specific volume with increasing depth is
far more marked in the upper water layers than at greater depths. This is correspond-
ingly shown in fig. 9 c. During a hea\^ gale the surface water is so stirred as to pro-
duce a homogeneous surface layer, the transition here answering to that apparent in
passing from fig. 9 c to fig. 9 d. In the spring, the melting of the ice occasions a down-
flow of ice-cold water from the surface to an intermediate depth. A homogeneous
layer is thus produced, here indicated by the narrowed portions in the diagram, fig. 9e.

a b

Fie

9. — Diagram of the stability of the sea water.

In the coastal zones, there is often a current of specifically lighter water. Owing
to the inflow from rivers and streams, the surface water b., ">mes especially stable.

CANADIAN FISHERIES EXPEDITION, 1914-15

233

Another maximum of stability occurs at somewhat greater depth where the transition
from the light coastal current to the heavier subjacent layer oc(«s. This is shown
in fig. 9 f . 'vl

All these features, together with otliers, are illustrated in p^^^es XII and XIII.
The diagrams for stability are, as will have been seen from the foregoing, extremely
instructive when discussing the condition of the sea and the causes which produce the
various hydrographical situations there occurring.

6.— INFLUENCE OF THE WIND UPON THE MOVEMENT OF SEA-WATER.

In chapter 3, the various effects of the wind upon homogeneous water and upon
water in layers, has already been shown, vide figs. 4 and 6. Still more remarkable is
the action of the wind upon water in which the specific gravity increases continuously
with the depth. Let fig. 10 be a vertical section through a sea basin containing such
water, the horizontal lines 1-7 representing the isosterics. We presume that, for the
time being, no other forces are at work here beyond that of gravitation, and that the
water is at rest; the isosteric surfaces will thus lie perfectly horizontal. In fig. 10, the
isosteres are closest at the surface of the sea, where the stability of the water will in
eonsequene-e be the greatest. Fig. 9 c gives the diagram of stability for fig. 10. If now a
wind commence to blow, a displacement of the upper water will occur, this following
the direction of the wind; as, however, the water particles belonging to an isosteric
surface cannot leave the same, and as no water can penetrate through these surfaces,
the effect of the wind in this case will be confined to the deformation shown in fig. 11.

Fig. 10. — Stable sea water in eciuilibrium.

Fig. 11.— Influence of ilie wind on stable
.sea water.

The isosteric surfaces retain their individuality, and the volume of water between them
remains unchanged despite the wind. The displacement of the water in the direction
of the wind causes the isosteric surfaces to slope more and more, giving rise to a strong
system of Archimedean forces, which tend to drive the surface water back against the
wind. These opposing forces continue to increase, until at last the water no longer
flows in the direction of the wind; a state of equilibrium is reached, and from the
magnitude of the Archimedean forces required to bring about the same, we may sub-
sequently calculate the force originally brought to bear by the wind itself. When the
wind grows fainter, or ceases altogether, the Archimedean forces drive the water back
in a direction opposite to that previously followed by the wind. As a rule, the water
now flows back too far, so that the isosteric surfaces slope the reverse way. This gives
rise to new Archimedean forces which send the water back once more in the original
direction of the wind. In this way the backward and forward movement may be
6551—19

234

DEPARTMEXT OF THE NATAL SERVICE

repeated several times, until equilibrium is attained. When this occurs, the isosteres
will be in preeist^^their old position, and the state of the water exactly what it was
before the commencement of the wind.

The sea-water-, thus reacts more after the manner of an elastic body than a fluid,
when subjected to the influence of forces acting upon it. The forces in question can
only occasion a certain degree of deformation, and as soon as they cease to operate,
the water returns to its former condition. External forces produce, so to speak, effects
as upon a mass of jelly.

The Archimedean forces thus play very much the same part in sea-water as that
of elasticity in a solid. It may occasionally happen that the external forces acting
upon the sea water reach a magnitude exceeding the highest possible value which can
be attained by the Archimedean forces. A catastrophe then takes place, and an
entirely new state of things is brought about, exactly as when the limit of elasticity
in a solid is exceeded.

The maximal value of the Archimedean forces is reached when the isosteres become
vertical. Should external forces exceeding this maximal value be brought into play,
then the water layers will jibe over, as shown in fig. 12, which illustrates the distribu-
tion of density under a very strong wind. Now, however, light water is brought down
beneath heavier; the stability is upset, and a strong vertical convection ensues, whereby
the whole of the water affected is mixed up into one single homogeneous layer. The
specific volume of this layer will, of course, be equal to the mean specific volume of
the strata of which it was composed, and between this and the water beneath there will
be a sharply defined difference of density. In the homogeneous layer, there are no
isosteres, and consequently, no Archimedean forces will be formed, so that the water
therein contained will follow without resistance the direction of external forces acting
upon it. The circulation here will therefore be highly intensive, as sh<twn in fig. 13,
so that the water will continue homogeneous, and exert a continual friction upon the
layer beneath, thus maintaining the sharply defined limit of density between the two.
This friction occasions a gradual absorption of the water from the lower layer, so that
the upper one w'ill tend to increase in volume and specific gravity.

Fig. 12. — Water layers jil»ing in a high wind.

Fig. 13.

-Strong circulation in surface
layer after jibing.

When the external forces which brought about the transformation have sub-
sided, and the isosteres have resumed their horizontal position, the distribution of
density will naturally not be the same as before the forces in question had commenced
to operate, vide fig. 10. Instead of this, we now find a homogeneous surface layer of
great volume, and between this and the water beneath, a sharply marked break in the
density, vide fig. 14. This is the reason why the greatest variation of density with

CANADIAN FlsHt:iUi:>i EXPEDITION, Wl.'rlo

235

depth in the sea is often found, not at the j^urfaee, hut at some distance beneath,
rule, fig, 9 d, and plates XIT and XIII.

Fig. 14. — State of sea water after a storm.

Obviously the greater the stability of the water, the more difficult will it be to
make the surface water jibe over in this manner; whence again it follows, that the
phenomenon is more easily occasioned in winter than in sunnner. In other words,
the surface water exhibits a far greater power of resistance to the wind in summer
than in winter. This peculiarity has been remarked by fishermen on the west coast
of Sweden, who declare that the sea-water is harder or heavier in summer than at
other times of the year.

With water in layers, the matter is naturally far simpler, vide fig. 6, than where
the density increases continuously with the depth. Even in such stratified water,
however, many dynamically and hydrographically interesting phenomena may occur.
It is instructive to begin by producing such experimentally, and afterwards observe
the corresponding realities in the sea ; by this method, as by no other, it is possible
to arrive at an intimate understanding of oceanographical phenomena.

Figf. 1 5.— Experiment illustrating action of wind ujion
water in strata.

I purpose now to describe some experiments which I have carried out as illus-
trative of the influence of wind upon stratified water. A tank 100 cm. long, 25 em.
deep, and 3 cm. across, with glass walls, was filled to a height of 10 cm. with fresh'
water. By means of a thin tube, heavier salt water was then introduced beneath this,
making another layer 10 cm. deep. With the aid of an electric arc lamp, a picture
of the tank was then projected on to a white sheet, whereby the separating surface
between the two water layers was rendered very distinctl.v visible, owing to the refrac-
tion of the light. As long as the water was left midisturbed, the boundary line was
horizontal, and the layer of uniform thickness. By means of a blower, a strong
current of air was then driven across the surface of the water, when the separating
line took the direction shown in fig. 15. A point especially worthy of note is the
depression at that end of the reservoir to which the wind was directed. This is

6551—19*

236

DEPART3IENT OF THE NAVAL SERVICE

caused by the water in the upper layer having its current there directed vertically
downwards, and striking against the separating surface. At the other end of the

5CH0NEN

RUGENJ

Fig. 16. — Wind and distribution of temperature, with
probable movement of the water, in the southern part
of the Baltic, 1 August 1907.

reservoir also, the separating surface is seen to be slightly rounded off where the
current turns. That corresponding deformations of the surface layer occur in the
sea will be seen from the hydrographical sections in figs. 16 and 17.

S-America
D°Long.\x/ 30

P,^55Ar

Africa

lOOLong. E

Fig. i:

-Wind, 1.5'' isotherm, and probable movement of the water between
Africa and S. America, lat. 20'" S.

Owing to the circulation in the surface layer in fig. 15, the water therein
remained very homogeneous. From the continual friction upon the layer beneath,
the surface layer absorbed into itself some of the water adjacent, and thus gradually
increased in volume. The longer the experiment lasted, the thicker and Salter would
the surface layer grow. The same thing would probably take place in the sea with a
<jontinual wind.

>»-

-^Wit^d

Light water "^*^=*=s»^^

Heavy water ~~~ i^:_jj^ J

Fig. 18. — Exi)eriment illustrating current opposed to the
wind on the weather toward shore.

I now poured a small quantity of fresh water into the water already in the tank,
as answering to rainfall, or inflow from rivers and streams into the sea. This fresh
water was driven by the current of air towards the end of the tank against which the
wind was blowing, forming a triangular inset there, as shown in fig. 18. It was here
■distinctly subjected to two forces, firstly the wind, endeavouring to bring about a cir-
■culation where the surface water moves in the direction of the wind, and secondly the
c'urrent beneath, seeking to induce a circulation where the surface water moves against
the direction of the wind. The latter, hoM-ever, obtained the mastery, as shown in

CANADIAN FISHERIES EXPEDITION, lOl'rlo

237

fig. IS. We see, then, that the peculiar phenomenon may arise of the wind occasioning-
a surface current in a direction opposite to its own, on the weather shore. This L
have, as a matter of fact, frequently observed myself in the Gullmarfjord, on the west
coast of Sweden. When the wind is blowing directly onshore, a situation exactly
identical with that shown in fig. 18 may arise. Should it, however, be blowing
obliquely towards land, then this will occasion a screwing movement in the triangular
inset, also probably in that beneath, vide fig. 19, showing direction of the wind and
movement of the water in Gullmarfjord, seen from above. The respective densities of
the water layers in the gulf of St. Lawrence are so similar to those in the Gullmarfjord,
that the same phenomenon should also be of frequent occurrence there.

Shore

Fig. 19.— Wind and wind currents in the Gullmarfjord.

At the point where the two surface currents meet, all floating objects, such as-
driftwood, cork, froth, etc., will collect; this line is therefore easily distinguishable.
Off the west coast of Sweden, there is, as a rule, a line of this sort generally to be seen
running parallel with the shore. This is the boundary line between the Baltic current,
and the heavier water outside. When the fishing boats sail from Marstrand out to-
sea, they often follow one another in a straight line. On passing this boundary, how-
ever, their line is broken, and the boats outside do not move in the same direction as
those within the margin, although steering the same course, and with their sails set
just as before. This is evidently due to the fact that the movement of the water is
not the same inside and outside the boundary line. A fisherman who had set his drift
net out one night right across the line, had it cut clean across, and the pieces drawn
into the mass of floating refuse. Next day he sailed northward along the line and
found them there. This shows that high relative velocities are to be found in this
drift line, which was only to be expected, after what Ave have seen in fig. 19.

The underlying strata are also aii'ected, through friction, by the layers acted on
directly by the wind. And it may then occur that even the cold deep water, when

238

DEPARTMEXT OF THE XAYAL SERVICE

drawn up to the surface on the shore where the wind is blowing seawards will develop
a movement opposed to the direction of the wind, vide fig. 20.

Fig. 20. — Current opposed to the wind on weather
shore and lee.

In large areas, the wind cannot be regarded as a constant current of air progress-
ing continuously over the whole area, but rather as a series of stormy gusts extending
over a wide expanse. Such a storm, acting upon water in layers, produces a very large
submarine wave, probably hundreds of metres high, which moves slowly forward in
the direction of the wind, ride fig. 21. This wave is caused by the friction between
the current of air and the surface layer. As the wave moves forward, the surface water
in front of it must pass over behind the crest of the wave. A strong current, moving
against the wind, thus arises in the surface layer, and this will make itself apparent
even before the storm itself has reached the same point, thus serving as a storm warn-
ing. From fig. 21, it will be seen that the current flowing in a direction opposite to
that of the wind continues to do so for some little time after the wind has come up.

Fig. 21.— Surface current on the approach of a storm.
but then decreases in force. Such currents against the wind have frequently been
observed in Canadian waters.

7._INFLLTENCE OF THE EARTH'S ROTATIOi^ ON THE MOVEMENTS
OF THE WATER IN THE SEA.

Of all the forces acting upon the sea-water, that of the earth's rotation is the
one which, as regards its effects, is most remarkable and difficult of comprehension.
It is frequently found to force light water downwards, and heavier water to the
surface, with the result that the distribution of density appears strange and
mysterious. I am inclined to believe that our inability to comprehend the effects of
this force is principally due to the fact that we have no senses for the direct per-
ception of the rotation of the earth. All our direct perceptions indicate the earth
as motionless. True, we have learned at school that the earth rotates, and can also
more or less form an idea of its doing so, but as a matter of fact, in our daily life,
as in the laboratory, we are independent of such rotation. All the small phenomena
around us we are accustomed to view from the standpoint of an immobile earth.
When, therefore, in discussing the movements of the sea, the rotation of the earth is
seen to take a prominent place, its effects appear to us strange and inexplicable.

A being situated somewhere outside our planet, and observing, not only the
phenomena taking place on the earth's surface, but also the rotation of the globe

CANADIAX FISHERIES EXfEDITIOX, 191',-15 239

itself, would be far better able to eonii)reheud the actual movement.s of the sea than
we are. From our point of view, the currents of the sea appear to evince an irrational
tendency to veer to the right; an extra-terrestrial being would, however, see in this
nothing but the natural effort of the water to continue its forward movement in a
straight line, as its inertia demands. Let us then imagine ourselves to be such beings,
viewing the earth from outside. We find, first of all, that the body of the planet
moves about its axis in the space of twenty-four hours. At the poles, the surface
of , the earth also moves at this rate of rotation. At the equator, the influence of
the earth's rotation is nil, as may be ascertained also by experiment with the
Foucault pendulum. In the Canadian Atlantic region, the rotation of the earth's sur-
face amounts, as circumstantially demonstrated in chapter 1, to about 11° per hour;
i.e., the Canadian waters make a full turn in something like thirty-three hours;
vide figs. 2 and 3. From fig. 3, also, we may see why it is that the water in more or
less inclosed areas circulates cyclonically. All the currents in the area tend towards
the right bank, and move along the same. This rule will always be found to apply
in high latitudes. The Gulf stream, for instance, transporting water from the tropics
to the Arctic ocean, keeps close to the coast of Europe, while the Polar current,
which carries the light Arctic water southwards, hugs the shores of Canada. The
result is a very marked cyclonic circulation in the North Atlantic ocean. In the
Xorth sea, the Skagerak, and in the Newfoundland area, the surface water every-
where exhibits a cyclonic circulation.

In the lower latitudes, on the other hand, the circulation of the surface water
is antieyclonic, owing to the strong anticyclonic winds, and the slight effect of the
earth's rotation there.

Let us now consider how this cyclonic and anticyclonic circulation would appear
to an extra-terrestrial observer. The earth's rotation is cyclonic; every sea-basin
thus also rotates cyclonically. When the water in any such basin circulates cyclonic-
ally in relation to the basin itself, this merely means that the rotation of the water
is more rapid than that of the basin. And when the water circulates anticyclonically
in its basin, this is in reality nothing but a cyclonic movement of the water at a
velocity inferior to that of the basin itself.

It is obvious, however, that the centrifugal force of a rapidly rotating water
layer will be greater than that of one rotating more slowly. When, therefore, the

Fig. 22. — Distribution of density in a sea
basin with cyclonic rotation of surface
water.

surface water in a basin circulates cyclonically. this water will be flung radially
outwards, so that the separating surface between this upper layer and the one
immediately beneath will no longer be horizontal, but will develop a depression on
the coasts, and a rise in the centre of the basin, vide fig. 22. The Archimedean
forces thus called into play will be kept balanced by the difference between the centri-
fugal forcer of the two layers.

240

DEPARTMENT OF THE NAVAL SERVICE

From the Archimedean forces, therefore, we can calculate the centrifugal forces,
and thus arrive at the transposition of the water. This ingenious method of cal-
culating the movements of sea water will be employed in the following, when dealing
with the iN^ewfoundland area.

A contrasted distribution of density arises when the surface water circulates
anticyclonically, as is the case in the horse latitudes. Here, the deep water rotates,
as a matter of fact, with the Atlantic basin; the surface water, however, moving at
a slower rate. The centrifugal force of the deep water is therefore greater than that
of the surface water, and the former is consequently flung out more strongly than
the latter. The result of this, again, is that the surface water keeps to the centrej
of the area (vide fig. 24 B), and this warm upper layer therefore reaches down at
this point to a depth of 600 metres, whereas at the equator, its depth is only 200
metres.

Now, as we know, the diagram of velocity for a vertical line through a sea cur-
rent assumes, owing to friction, the form of a parabola, the velocity being at its
maximum a little below the surface of the sea. In the lower portions of the current
it decreases greatly with increasing depth. When, therefore, the surface water in
a basin circulates cyclonically, as before described, the cyclonic circulation and the

Fig. 23.— Screwing movement of surface water
in cyclonic circulation.

centrifugal force will reach their maximum near the surface of the sea, decreasing
rapidly with increasing depth. And the actual surface water will be flung out more
strongly than the water in the lower portions of the surface layer. The effect of
this is that the former moves toward land, and the latter out to sea (vide fig 23 B).

CANADIAN FISHERIES EXPEDITION, lOl'rlo

241

And ill its forward progress, the current thus makes a kind of screw movement,
exactly corresponding to the screw^ing forwa:.'ds of an ordinary screw, fig. 23 A.

In the Sargasso sea, tho anticyclonio circuhition is at its maximum in the
surface of the sea, the centrifugal force being there at a minimum. The lower
portions of the surface layer are flung outwards with greater force than the surface
water itself. This gives rise to a screwing movement of the water, the surface water
tending towards the centre of the Sargasso sea, and the deep water moving outwards
from that centre, as shown in fig. 24. This explains the collection of floating matter
in the Sargasso sea.

Fig. 24. — Movement of the water in the Sasgasso sea.

This tendency to screw forward is found in all sea currents in high latitudes,
as a result of the earth's rotation. But the water of the northern hemisphere moves
after the manner of an ordinary right-turned screw; that of the southern, however,
screwing towards the left. The screwing tendency increases as sin (^ where (^ is the
geographical latitude. Thus, at the equator, it is nil, and has its maximum at tha
poles.

If the water of an intermediate layer is moving in a certain direction, relatively
to the layers above and below it, then it will turn off to the right from that direc-
tion, until it reaches the right side of the basin, against which it is pressed (fig. 25).
Such a current will have its maximum of velocity at the centre, where the water
is forced most strongly to the right, returning in the upper and lower portions of
the stratum. There will thus be two screwing movements in such an intermediate

242

DEPARTMENT OF THE NAVAL .SERVICE

layer. The divergence of the isosteric surfaces (vide fig. 25) is one of the surest)
indications of the existence of such a deep water current.

Fig. 2.5. — Screwing movement in a deep water
current.

Finally, some experiments made with a rotating water tank remain to be
described. This tank was 30 cm. long, 10 cm. broad, and 10 cm. high. A surface
layer of fresh water, 4 cm. deep, was poured in, and a bottom layer of salt water,
also 4 cm. deep, introduced beneath the first. Before the tank was set in motion,
a vertical current of air was applied to the surface of the water; the result will be
seen from fig. 26. Under the influence of this current of air, the surface layer>
diminished in thickness, the bottom layer increasing, evidently as a result of fric-
tion between the surface of the water and the air, which poured out radially to all
sides. The tank was then caused to rotate about a vertical axis through its centre,
when the situation shown in fig. 27 was observed ; i.e., the exact opposite of that shown
in fig. 26. The cause of this accumulation of the surface water under the air cur-
rent is evidently this: the rotation of the surface water is somewhat retarded by
the radially directed air, which renders its velocity less than that of the tank,
whereas the bottom layer of water rotates at the same velocity as the tank itself.
Consequently the centrifugal force would be greater in the bottom layer than in the
surface water, and the bottom water would therefore be driven out to the ends of
the tank, while the surface water massed in its centre.

w/////yy///y///^'i'/^////y^//'y/'^/4V^/'^r'yyy^^yy^r^yyyy./y^yyy^^^.

Fig. 2H. — Experiment with vertical air bla.st against surface of water in layers.
(Tank at rest.)

liastly, by means of a series of obliqi;ely placed tubes, a cyclonic circulation
of air was applied to the surface of the water, the effect of this being to induce a
rotation of the surface water at a higher velocity than that of the tank. This
brought about the same distribution of the water mass as shown in fig. 26, evidently
here owing to the fact that the centrifugal force was in this case greater in the sur-
face layer than in the bottom water.

In the sea, therefore, an anticyclone should occasion an accumulation of the
surface water beneath its centre, a good example of which is afforded by the Sargasso
sea. A cyclone, on the other hand, would drive the surface water outward? to all
sides, and draw up the bottom water beneath its centre.

CANADIAN FISnERIE^ EXPEDITION, 191.',-i-^

243

The vortical movemonts of tho wator dpscrihcd in this chapter, which are due
to the earth's rotation, are naturally opposed, in a very important deprree, by the
Archimedean forces. With water of very hifrh stability, these forces may entirely
prevent the screwing movement of the water, all that takes i)lace beinfr then a current

Fig. 27. - Experiment with \ertieal air blast against surface of water in layers.
(Tank iritating. )

in the isosteric surfaces, which are deformed in the manner shown in fig. 22. In a
coastal current, where the water is in layers of great stability, the surface water will
therefore flow parallel with the coast. If, however, the stability of the strata be so
slight that the deflecting tendency of the earth's rotation exceeds the maximal value
of the Archimedean forces, then the screwing movement will thoroughly stir the
water in which it takes place, rendering the layer highly homogeneous, so that the
dividing surface between it and the next will be sharply defined. After this, there
will be nothing to hinder the screwing movement of the water in this homogeneous
layer, and the movement in question will thus attain its full development. This
explains the high component of movement towards the coast in the surface portion
of the comparatively homogeneous water south of Newfoundland, whereas in the
Gaspe current, a layer formation of great stability, no such landward movement takes
place (vide fig. 28). Even down on the banks to the south of Xewfoundland, the
water often flows northward, the bottom water, owing to the screwing movement, natur-
ally having a component southwards. Thus the dangerous character of the Canadian
Atlantic coast as regards navigation is due to the homogeneous nature of the water.
If at any season the sea-water there should be overlaid by lighter surface water in
stable layer formation, there would then be no danger of ships being driven on shore
by the current, as long as such surface water was present.

244

DEPARTMENT OF THE XATAL SERVICE

In a similar manner, we should be able, from the movement of the water, to-
ascertain the stability of the same. If the water flows parallel with the coast, it is
stable; whereas water setting in towards the shore will be homogeneous. On the
eastern side of jSTewfoundland, for instance, the water flows up into the baj^s (vide

S ^■

P3 «-
_2 »

eS

00 ^

^ a

O -J

^^

O fli

fig. 28). From this we may conclude that the water here is of but slight stability.
On the southeast coast of Newfoundland, on the other hand, the water sets outwards-
from the shore, even occasioning a reverse current in towards land. Here, therefore,
the water is in stable layer formation.

CANADIAN FISHERIES EXPEDITION, 1914-15

245

8. IXFLUEXCE OF MELTlXG ICE UPON THE MOVEMENTS OF SEA-

W»ATER.

One of the strongest and most effective causes of ocean currents and hydro-
graphical changes is, as Prof. Otto Pettersson' has shown, the melting of ice. If a piece
of ice be placed in a tank of sea-water, the water will soon exhibit very strong and
distinct current movements, the melting of the ice also occasioning marked alterations
in the temperature, salinity, and specific gravity of the water.

Professor Pettersson found by his experiments that the melting of the ice gave rise
to three currents in the water, a cold surface current of low salinity proceeding in a
direction away from the ice; below this a warm salt current moving toward the ice; and
finally a cold salt bottom ciirrent away from the ice again.

I have also carried out some experiments of this nature with melting ice in sea-
water. A glass-walled tank, 350 cm. long, 40 cm. broad, and 40 cm. deep, was filled
with sea-water to a height of 35 cm. In one end of the tank was then placed a rectan-
gular piece of ice measuring 61 cm. length, by 40 cm. width, and 23 cm. thickness.
At the other end of the tank a current of water was introduced at a temperature of
8° C. and with a salinity of 30 per cent, the inflow taking place at the rate of 12 cm.
per second with a corresponding outflow from the surface so as to maintain a con-

/C£:

Fig. 29. — Ice melting experiment.

staiit level. The outflow took place in a separate compartment of the tank, 75 cm. long,
divided off from the remaining, consequently 275 cm. long by a partition 25 cm. high,
so as to leave free communication between both portions of the tank through the space
of 10 cm. above the partition, vide fig. 29. The object of this inflow arrangement was
to procure stationary conditions in the tank. The system thus arrived at. by the way,
is very much like the conditions prevalent in the gulf of St. Lawrence, which commu-
nicates with the ocean through Cabot strait.

The block of ice was placed in the tank at 11 a.m., and immediately commenced
to melt at the rate of 0-80 cm.^ per second. As the sun-omiding water was brought into
circulation, the rate of melting increased, so that by 12 o'clock it was 1-24 cm.^ per

1 O. Pettersson. On the influence of ice-melting upon oceanic conditions,
grafisk-bio'.ogiska liommissionens skrifter II. Gothenburg, 1905.

Svenska hydro-

246 DEPARTMENT OF THE XAYAL SERVICE

second, and by 1 o'clock 1-26 cm.'' per second. After this it decreased, chiefly owing to
the fact that the surface of the ice block had diminished in size, but also on account of
the lower temperature of the water in the tank. At 2 o'clock the rate of melting was
0-97 cm." peir second, at 3 o'clock 0-70, at 4 p.m. 0-60, at 5 p.m. 0-53, at 6 i>.m. O'-50,.
at 7 p.m. 0-50, and at 8 o'clock 0-50 cm." per second. Fig 30 shows the changes which
took place in the shape of the ice during the process of melting. The depression A on
the front of the block was caused by the warm water pressing against the ice at this
point, and giving off its heat there, whereafter the water now cooled sinks down past
B, where the ice melts at a slower rate, owing to the lower temperatui-e of the water
coming in contact with it there.

In order to measure the movement of the water in the tank, a solution of
fuchsin in alcohol was prepared, in such proportion as to get a specific gravity as
nearly as possible equal to that of the water. A portion of this solution was dis-
charged into the water through a capillary glass tube at a point some 20 cm. in front
of the depression A in the ice (fig. 30). The solution was carried at an even rate of
speed into the depression, then sinking downwards, following the outline of the ice.
At B, the rate of movement was diminished, and a small cloud of fuchsin was formed
off the projecting point there. After this, the fuchsin particles were gradually driven
in under the ice. The lower portions of the block was passed by at a great rate of
speed, until the fuchsin reached the point C, where it slowly sank, and was caught
by the bottom current which carries the water away from the ice.

CANADIAN FISHERIEii EXI'KIHTION, 101.',-15

247

248

DEPARTMENT OF TEE NATAL SERVICE

A picture of the ice block being projected on to a white sheet by means of an
arc lamp, it was seen that streaks were moving upward on the cloth, indicating that
some of the melting water from the surface of the ice rises to the surface of the
water, forming there a surface layer of fresher water ; some portion of it, however,
doubtless becoming mixed with the sea-water which is melting the ice and sinking

Fig. 31. — Distribution of^saii«+ty near the ice.

down with it. Vide figs. 31 and 32, showing distribution of salinity and temperature
in front of the ice block.

In order to measure the movement of the water more exactly, a long capillary
pipette was filled with potassium permanganate solution, and introduced vertically to
the bottom of the tank from above. On being drawn up, it left behind it a fine vertical
thread of the solution, which was afterwards visibly curved by the current. After the
space of two minutes, a drawing was made of the thread as it then appeared. Fig.

Fig. 32.

-Distribution of the tempeiaftTwe near the ice.

33 shows the original vertical and subsequent altered course of the permanganate line.
The horizontal lines thus indicates the movement of the water particles during the
two minutes.

CAXADIAX FlHUEltlEii EXPEDITION, I'Jl'rlo

249

The velocity of the water was also measured in other parts of the tank. Fig.
34 shows the results of these measurements. It will be seen that the surface current is
insignificant, that at the bottom, however, being quite considerable. The water actually
moving towards the ice forms two currents, with a minimum of velocity between, the
upper current being directed towards the front of the ice, and the lower against its
underside, where the force of attraction appears to be very great. As a matter of fact,

Fig. '6'6. — Movement of the water near the ice.

the ice melts equally much on its lower side as on its face, and the rear i)ortion of the
ice diminished, at any rate to begin with, more rapidly than the front part, vide tig.
30. The greatest velocity of the water and the greatest acceleration found in any part
of the tank were localized about the lower side of the ice block. In the sea. where the
vertical extent of the ice is insignificant as compared with its horizontal extension, this
fact should probably be of the very highest importance.

6551—20

250

DEPARTMENT OF THE yAYAL SERVICE

^

ca:sadia^ fisheries expedition, laiJf-is

251

In the experiment here described, it was not always possible to maintain a constant
degree of salinity in the inflowing water. When the salinity increased, a warm saline
layer with a slow inward movement was formed at the bottom of the tank. Above this
was the cold outgoing current of lower salinity. And above this again warm water
poured in towards the ice, with finally, at the surface, a thin layer of brackish water
directed outwards, vide fig. 35. This situation corresponds very closely to the actual
conditions in the gulf of St. Lawrence, where a cold intermediate layer is also found.

ioffi

Fig. 30. — Muvfciiient of the water by
the melting of the ice in theGull-
marfjord.

The experiment and observations mentioned above give a good insight into the
origin and formation of the intermediate cold water layers in the Newfoundland area
(vide tables IV and V). It has plainly been formed by the melting of the ice in the
gulf of St. Lawrence and the Labrador current.

When the ice was melting in the Gullmarfjord I noticed it carefully, and measured
the velocity of the water in a vertical line inside the ice edge, vide fig. 36, and also
the temperature of the water in a section at right angles to the ice edge, ride fig. 37.
From fig. 36 it will be seen that a strong current of water directed inward towards the
ice existed down to 10 metres depth, and beneath this, a slighter outwards current right
down to the bottom. Fig. 37 gives a verj- clear view of the manner in which the cooled
water sinks in portions from the ice down into the depth below. The same thing doubt-
less takes place on the melting of the ice in the gulf of St. Lawrence, and in the Arctic
ocean and other places.

6551— 20i

252

DEPARTMENT OF THE XAVAL SERVICE

«n

^

J^

<0

«0 0*0 e'£> «*^
*< Vs e^ c\4

Ki >0 ^

VAXADIAX Fl.SBERIES EXPEDITIOX, IDl'rlo

253

9. INFLUENCE OF FKICTIOX UPON THE MOVEMENT OF SEA-WATER.

Internal friction exerts a powerful regulating influcMico uixju the movement of
the water in an ocean current. In order to compreliend this, it will be necessary to
consider the forces acting upon the water through friction. And it will simplify
matters if we here disregard the insignificant vertical velocities in the water. Let
us suppose that the water particle a has a velocity inferier both to that of the water
above and of that below, vide fig. 38 a. The velocity of a wiU then be accelerated by
friction with both these layers, until finally it attains their velocity. In this instance,
then, the velocity of the water particle is accelerated by internal friction.

a,

*-

Vj

V,

(X

— ^

V2

r

/

>,

\

J

- >^

^

Vz

^

V,

oC

\'2

/ >
/

/

./-

i

\

— ^

Fig. 38. — Frictional force as indicated by the
iiiovemwit of the watei in a current.

If, on the other hand, the water particle a is of greater velocity than the water
above and below (fig. 38 b), it will be retarded until its velocity is equal to theirs. In
this instance, the friction acts as a check upon the movement of a.

Again, if the velocity of a be equal to mean of the two values for velocity of the
Layer above and of that below, (fig. 38 c), then the retarding effect of the one will be
equal to the accelerating influence of the other; i.e., the resultant value of the forces
acting upon a through internal friction will be nil.

If the velocity of the particle a be not equal to the mean of the velocities above
ar.d below (fig. 38 d), then the friction in a will be the greater between it and the layer
having the greater divergence in point of velocity from the particle a. The result of
tiiis will be that the velocity of a is finally brought, through friction, to a value equal
to the mean of the two velocities in the water above and below it.

Where the current has a screwing movement, so that the vectors \\ and \u (in fig.
38 d), do not lie in the same plane, or take opposite directions, then the vector repre-
senting a will constantly endeavour to attain a velocity and direction equal to the
mean values for those of the ve-ctors v\ and V2.

If we measure the velocity of the water at a great number of points in a vertical
down through the sea, and draw up from these a co-ordinate system with the velocities
as abscisses and depths as ordinates, then we obtain a diagram of velocity for the
vertical in question. Where the resulting diagram is convex, as in fig. 38 e, then
the velocity of each particle will be greater than the mean value of those immediately
above and beneath; the current is then retarded by internal friction. If, on the other
hand, the diagram presents a concave figiu-e (fig. 38 f). then the velocity of each
particle is less than the mean value of the velocities in the layers immediately above
and below, wherefore the current will be accelerated by internal friction.

254

DEPARTMENT OF THE NAVAL SERVICE

As a rule, the friction has a retarding effect upon the currents in the sea, so that
the diagrams of velocity through these are generally convex. Let us suppose that all
the water i)article3 in one and the same current are retarded with the same fore^.
The difference between the velocity of one water particle and the mean velocities
above and below will then be constant for all water particles throughout the currei\t
A diagram of velocity answering to these conditions is easily drawn, the figure being
in this case a parabola (fig. 39).

Fig. 39. — Diagram of velocity for a current
with constant frictional resistance.

If the equation for this parabola be

u = az' (3a)

then the force with which the friction retards each ccm. of the current will be

f = -2ak (3&)

where A; is the coefficient of friction. The more acute the parabola, the greater will be
the check exerted upon the current by friction. In currents where the water flows at a
great velocity in a thin layer, the retarding force is therefore very great, whereas in
currents of great volume such as the Gulf Stream, it is insignificant.

In any current, where stationary conditions have been arrived at, the frictional
resistance in the longitudinal direction of the current is nearly equal to, albeit
naturally in an opposite direction to the force by which the current is impelled, and
we can therefore, from the diagram of velocity, directly ascertain this force. If such
a stationary current be disturbed by external influences, as for instance by that of the
wind, the appearance of the diagram of velocity is at once changed, and we may, from
the deformation occasioned therein, ascertain the magnitude and extent of the effect
produced by the disturbing force upon the current. A diagram of velocity is therefore
the best means we have of studying in detail the dynamic conditions of the ocean
currents.

This analysis of the diagram of velocity is best carried out by dividing the curve
into so small portions that each can be regarded as a parabolic curve with horizontal
axis. For each such curve,, we then determine a and fj according to equations 3 a
and 3 b.

Let us, for instance, consider the effect of the wind upon a surface current in the
sea. The diag'ram of velocity for such a current normally takes the form of a para-
bola, the point of which lies immediately under the surface of the water, vide fig. 40 a,
with a wind blowing across the sea in the same direction as the current, the diagram
will assume the form shown in fig. 40 b, i.e. its upper portion will become concave, while
the remaining parts will still continue convex. The upper portion of the current is
thus accelerated by the friction. The effect of the wind extends down as far as the

CAXADIAX FlsHEh'IES EXPEDITIOX, l'Jl.',-lo

255

deformation of the diagram takes place, and by calculating a and / for the different
parts of the current, we can immediately ascertain the magnitude of the force acting
upon each ccm. of the water by means of the wind. If, however, the wind be blowing
against the current, then the diagram of velocity will be strongly curved back at the
surface, vide fig. 40 c. Here the retarding force of the friction is very great, whereas
at greater depths it retains its normal value. In this case likewise we may, by divid-
ing up the diagram and finding a and / for each portion, ascertain the magnitude of
the effect produced by the wind at ditforeut depths.

XL

Fig. 40. Diagram of velocity fur a surface current in
calm weather and with wind in same and the oppo-
site direction.

In dealing thus with the diagram of velocity, due regard should be had to the
imperfection of the methods of measurement. Thus the small irregularities in the
upper part of the diagram fig. 36 cannot be considered as reflecting actual conditions,
but are rather due, partly to the inaccuracy of the instruments employed, partly to the
fact that the measurement.s were not taken at exactly the same time for the different
depths. If these irregularities be levelled down, however, the parabolic form is quite
distinct. We find then, that the water down to 10 metres depth is sucked in under the
ice with great force, and that beneath this surface current, two outward currents of
inferior velocity are found at 13 and 35 metres depth. The water between these last-
named currents is drawn along by tliem.

The foregoing examples should suffice to give an idea as to the great value of the
diagram of velocity in calculating the forces acting upon a current, in considering the
disturbances to which it is subjected, and in studying its nature and composition
generally. Such diagrams 'should therefore be more widely employed in marine
investigations than has hitherto been the case.

10.— ON THE CAUSE AND THE EFFECTS OF OCEAX CURREXTS.

The causes which give rise to currents in the sea are either external forces, such
as the action of the wind, or physical changes in the sea-water itself, occasioning an
alteration of its specific gravity. We have thus two distinct categories of ocean cur-
rents, differing widely in character, and it is important to have a clear understanding
of these.

If the surface water in a given area be subjected to physical change tending to
increase its specific gravity, as for instance by cooling or evaporation, it will com-
mence to sink, and the lighter surface water surrounding will flow in from all sides.
And owing to the rotation of the earth, a cyclonic movement then sets in about the
sinking centre. We have thus a movement in towards the centre, and at the same
time a cyclonic movement round that centre, as shown in fig. 41 a. If, again, a cyclonic
wind, by friction upon the surface of the sea, should set the surface water in cyclonic
circulation, then the current in question will, owing to the earth's rotation, veer off

256

DEPARniEyr of the xatal service

to the right, i.e. out from the centre. In this case, then, a cyclonic divergent niove-
raent is brought about, vide fig. 41 b.

x:i

Ar

Fig. 41. — {a) Cyclonic current about a sinking centre.

{It) Cyclonic current produced by c.yclonic wind.

(c) Anticyclouic current about a rising centre.

(d) A nticyclonic current [iroduc^d by anticyclonic wind.

If, however, the specific gravity of sea water be diminished by physical change at
any point, the water will rise towards the surface, spreading out there in all directions
from the rising centre. And the earth's rotation occasioning at the same time an anti-
cyclonic circulation, the total movement will then be divergently anticyclonic, fig. 41 c.
If, on the other hand, an anticyclonic wind should set the surface water in anticyclonic
circulation, then the current will be forced in by the earth's rotation towards the
centre, giving rise to a convergent anticyclonic movement, fig. 41 d.

It is of course obvious, that a current concentrating upon a given centre will be
far more strongly marked than one spreading its waters out in all directions. A cur-
rent occasioned by Q;v'clonic wind will therefore be but slightly perceptible, while those

CANADIAN FISHh'h'IES EXPEDITION, Wl'rlo 257

induced by the action of anticyclonic winds, such as the current round the Sargasso
Sea, and the analogous currents in the South Atlantic, the Indian ocean and the
Pacific, will be far more markedly apparent. Moreover, the anticyclonic currents pro-
ceeding from a rising centre outward, will be comparatively insignificant, whereas the
cyclonic movement of water in towards a sinking centre, e.g., towards the Arctic region,
or the point where the Labrador current disappears, etc., will be strongly marked. We
liave, then, the following rule: Cyclonic currents in the sea are occasioned by physical
causes, the anticyclonic currents by the action of the wind.

As the wind has no immediate effect upon the specific gravity of water, it follows
that a current occasioned by the wind will be restricted to a single water layer, and
is, in consequence, limited in extent, and simple in character. The Sargasso current,
{vide fig. 24) may, as a matter of fact, be taken as the type of all great wind currents
in the sea.

Despite their simplicity of character, however, these anticyclonic wind currents
nevertheless present many features of interest, and are well worthy of further study.
Such a vortex, with its powerful pressure in towards its centre, will be highly coherent
and, in spite of the enormous extent involved, of distinctly individual character, with
marked isolation from the surrounding water. One result of the pressure on the centre
is that the vortex there attains a considerable depth. The Sargasso current, for in-
stance, extends down to 600 metres. And, further, the strong vertical movement of
the water in such a vortex enables it to carry down the heat of the surface water to a
great depth ; there is a continual wearing upon and heating of the subjacent colder
water, so that the vortex is constantly intaking and assimilating water from below.
The Sargasso current discharges unto the Gulf Stream 25,000,000 tons of water per
second, which is as much as to say that it draws from its substratum just that quantity
of water every second.

Currents arising from physical changes in the sea-water, on the other hand, are
otherwise constituted, and behave in a very different way. They are not restricted
to a single layer, but may traverse several such, and have thus far greater freedom
of movement than the wind currents. Consequently, it is upon the former that the
tiisk of bringing about interchange between the waters of differ 3nt regions and different
depths devolves. The Gulf Stream is the type of this category.

The motive power in ' these currents is supplied by the Archimedean forces in
the sea. When the specific gravity of the water in a certain layer has been sufficiently
increased by physical change, it sinks down thence to a subjacent layer answering to
its own specific gravity ; where a decrease in the specific gravity takes place, the move-
ment is of course reversed. In the Gulf Stream layer, water is introduced from the
subjacent layer owing to rise of temperature taking place in the tropics; in the Arctic
regions, on the other hand, water from the Gulf Stream passes, on cooling, from that
current to the layer beneath.

Where water is thus introduced into a layer, the layer in question becomes
thicker than its surroundings, and Archimedean forces then arise which drive the
water of that laj^er from its place. Similarly, a layer losing some of its water becomes
thiinier, and the same forces tend to lead water thither from without. Owing to the
earth's rotation, this movement of the water proceeds, not in a straight line, but in
V- spiral, as shown in figs. 41 a and c. If, in one and the same layer, water is intro-
duced at one point and water carried off at another, then the layer in question will
become thicker at the former than at the latter, giving rise to Archimedean forces
which drive the water from the point of inflow to the i)oint where water i>asses out.
The Gulf Stream, for instance, is 600 metres deep in the tropics, but only 200 metres
deep at Spitzbergen. We see, then, that the Archimedean forces in the Gulf Stream
drive the water from the tropics towards Spitzbergen. Owing to the earth's rotation,
the movement in question becomes S-shaped, vide fig. 42. If the water at the i)oint

253

DEPARTMENT OF THE NAVAL SERVICE

of inflow be iSet in motion by an anticydonic wind, then the physical process by which
the water is introduced is transferred to a greater depth, whereby the Archimedaan

Y\g. 42 — Current from centre of ])n)duction to cencreof consumptioii in an oceanic layer.

forces attain a higher degree of intensity, and the current becomes greater. This takes
place in thel Gulf Stream, vide fig. 43.

Fig. 43. — Schematic diagram showing
movement of surface water in the
Gulf Stream.

CA\A1)IA\ FISHERIES EXPElJlTIOX, lOUf-lo 259

The effect of the currents origiuatinfr in ])hysical change in the water is then
simply that of transporting water of a certain character from a region where such
water abounds to regions where it is rare. And the quantity of water carried by such
a current will depend entirely upon the production and consumption of the kind of
water in question. The Gulf Stream carries about 25,000,000 tons of water per second.
Hence, it follows that a corresponding amount of such water is produced in the tropics
and consumed in the Arctic regions at the same rate.

And from this we may also conclude, that the complementary physical processes
whereby water is added to or drawn from a certain layer adapt themselves so as to
balance one another. What takes place is evidently this : a decrease of the quantity
of water in a layer favours the development of forces tending to introduce water from
without, and vice versa. And the present state of the water throughout the sea is the
rei^ult of thousands of ;veari of such adaptation.

The Archimedean forces which drive a current of this nature adapt themselves to
the quantity of water to be carried forward and the degree of resistance to be encoun-
tered. In order to understand this, we may once more take the Gulf Stream as an
example. If the production of Gulf Stream water in the tropics, and corresponding
consumption of the same in the Arctic regions were to cease, then the lower boundary
surface of the Gulf Stream would soon become horizontal, and the Archimedean forces
which drive the current forward would disappear, with the result that the forward
movement of the water itself would cease. If, on the other hand, the production and
consumption of Gulf Stream water were to become greater than is at present the case,
then the lower boundary surface of the Gulf Stream would assume a still steeper slope,
and the Archimedean forces attain a higher degree of intensity than at present. This
increase of force would arise in order to meet the necessity for transport of a greater
volume of water than the Gulf Stream is now required to carry.

In order to demonstrate the importance of the Sargasso vortex to the Gulf Stream,
the following experiment was made. A rectangular tank, 50 cm. long, 50 cm. deep, and
5 cm. broad, and having glass walls, was tilled with water, and heating and cooling
apparatus introduced, the latter constructed on the same principles as applied to the
heating of rooms, etc., i.e., consisting of metal receptacles through which a current of
warm or cold water could be transmitted. The pipes through which the heating or
cooling water was carried to the receptacles were carefully isolated. In accordance
with the conditions actually met with in the ocean, the cold centre was placed at the
surface of the water at one end of the tank, and the warm one a little below the surface
at the other end. The cold centre thus represents the cooling of the water in the Arctic
regions, the heating apparatus answering to the corresponding influence at the bottom
of the Sargasso vortex.

After the experiment had been in progress for some time, and stationary condi-
tions arrived at, some potassium permanganate solution was introduced into the water
near the middle of the tank, and immediately beneath the surface. The solution,
easily visible on account of its colour, moved over to the cold centre, and then sank to
the lower level of the warm centre, moved across to this, and then rose thence to the
surface of the water, recommencing here its movement towards the cold centre again,
as shown in fig. 44 a. Owing to the force of the circulation, the circulating layer of
water soon became coloured right through, until only a narrow strip running obliquely
down remained untinged, vide fig. 44 b. At last this, too, disappeared, and the entire
layer was coloured. The water layer beneath the warm centre remained entirely
un'coloured, thus indicating that no interchange takes place between the circulating
layer and that subjacent. On introducing a similar coloured solution into this lower
k.yer, it appeared that the movement of the water here was altogether insignificant.
The temperature of this layer was the same as that of the cold centre itself. The cur-
rent leading from the cold to the warm centre was slightly warmer than the bottom

260

DEPARTMENT OF THE NAVAL SERVICE

layer, but tlie warmest water in the tank was that which flowed from the warm centre
to the cold. 1

XX.

I

>c

jd

J[ yn/ |y w !»/ »/ "' *^ V i*^'"

lA-'vl' H V< ^\y WWW

cfC ccccccccc ctccccc I A-> t=

Fig. 44.— Experiment illustrating circulation of the Gulf Stream.

A further experiment was thereafter made with both warm and cold centres placed
at the surface of the water. When stationary conditions had been reached, it was here
found that a very slight degree of circulation was taidng place between the warm and
the cold centre, the entire remaining mass of water in the tank being motionless, as
shown in fig. 44 c. Finally, the cold centre was placed at a lower level than the warm.
In this case, as with the foregoing experiments, a highly intensive circulation at first
arose throughout the whole of the tank, but as soon as this had ^ given place to a
stationary situation, it was seen that the entire mass of water in the tank remained
altogether motionless. The water at a higher level than the lower side of the warm
centre had then the same temperature as the warm centre itself, and that below the
level of the top of the cold centre the same temperature as this latter, vide fig, 44 d.

CANADIAX FISHERIES EXPEDITION, 191'rlo 261

From these experiments important conclusions may be drawn with regard to the
(}ult' Stream. The actual bottom water of the ocean does not participate in the cir-
culation of this current, which affects only water within the depth to which beat is
carried down by the vortex of the Sargasso sea. The Gulf Stream thus presents a
well-defined, closed circulation with a warm surface current from the tropics to the
Arctic ocean, and a cold, deep-water current in the opposite direction. It is at the
surface of the water in the Arctic, and at the bottom of the Sargasso vortex in the
south, that the physical changes take place which give rise to the circulation of the
entire current. From the experiments referred to it is seen that these changes act
in co-operation, the quantity of water heated in the tropics corresponding exactly to
the amount cooled in the Arctic. Even when the warm and cold centres are placed
at the same level, or the former at a higher level than the latter, this rule is strictly
complied with. (In the last case, the quantity of water cooled and heated is nil, the
centres being surrounded by water of their own respective temi)erature.) This remark-
able adaptation of the physical processes is perhaps the most important factor in
regulation of the condition of the sea.

From fig. 44 b it will be seen that if the Sargasso vortex did not exist, and the
sea-water were only heated by the direct action of the sun's rays upon its surface,
then there woiild be no Gulf Stream, but only a very slight surface current. The
oblique strip in fig. 44 b corresponds to the lower surface of the Gulf Stream, -which
is likewise situated at a greater depth about its warm centre in the tropics than at
the cold centre in the Arctic.

The experiments indicate, as a general rule, for the two complementary physical
changes, that the process whereby the specific gravity of the water is reduced must
take place at a greater depth than that which increases it, and that the greater this
depth the more easily will a current develop. If, however, the two processes take place
at the same level, or with the reduction of specific gravity at a higher level than the
reverse process, then no current will be produced thereby. It is thus not all physical
processes in the sea which give rise to ocean cui-rents.

It may occasionally happen that two opposite physical processes at the same
level enter into co-operation, and thus set up a current. This is accomplished by a
massing of the products of the one process until the difference of level necessary for
the propulsion of a current is reached. The Labrador current is itself an instance of
a current originating in just this very way. The melting of the ice in the Arctic
basin produces a mass of brackish water, which has to be carried away. This water
therefore collects until it has formed a layer so deep as to be capable of forming a
current, the volume of the latter tlien corresponding to the further production of
Drackish water beyond that point.

As to how far the Gaspe current should properly be considered as belonging to
this last category is a question whicb can only be determined by further investigation.
The physical process in which it originates is the mixing of St. Lawrence water with
sea-water outside the mouth of the river. It is possible that this mixing process
extends, owing to ebb and flow of the tide, down to a considerable depth. It may,
however, take place at the surface, in which case the mixed water would only by
accumulation attain a sufficient depth to give rise to a current, w'hen the amount of
water transported thereby would answer to the quantity of mixed water thereafter
produced outside the mouth of the St. Lawrence.

The Gaspe current is one of the few ocean currents which may conveniently be
observed and studied, as regards cause and progress, by hydrographical measurements
at its point of origin, throughout its course, and at its termination. Such study is,
moreover, of the highest importance, not least as a means towards the better compre-
hension of similar problems which present themselves in the case of other currents
whose origin and progress are less easily discernible. The value of the Gaspe current
in this particular respect has, as a matter of fact, already been manifested, the investi-

262

DEPARTMENT OF THE NATAL StERTICE

gations of Dr. W. Bell Dawson^ upon this current and its effect on the circulation in
the gulf of St. Lawrence having been of great assistance to me in the preparation of
this chapter.

In order to demonstrate the effect of the wind upon the Gulf Stream, the follow-
ing experiment was carried out. An elongated rectangular tank with glass walls

Calm

Fair wind

^^ — ^^^ — -^ — ->^ — ^-^^ — ^

('•i^i'-'i'^^ ''' ^^'•'iif/ ' ■■' ■■'' "■i»'. '.■.■■»,. .....1. .... .'.'>'■' L.-'i-'u i";x^.

1

Contrary wind

Fig. 4.'i. — Influence of the wind upon the Gulf stream.

(vide fig. 45) was furnished with hot and cold centres, the former at one end of the
tank, near the bottom, and the latter at the other, at the surface. The upper diagram
in fig. 45 shows the circulation this produced. On introducing a coloured solution,

1 W. Bell Dawson. Survey of Tides and Currents in the Canadian Waters. Vide series
of Reports issued by the Department of Naval Service, Ottawa.

CANADIAN FISHERIES EXPEDITION, 191.'rlo 263

there appeared the oblique strip which separates the heated water from the cooled,
answering to the under surface of the Gulf Stream in the sea. By means of an elec-
tric turbine, a current of air was then directed through a number of tubes set obliquely
to the surface of the water, producing a very effective tangential wind action uix)n the
same. The second diagram in fig. 45 illustrates the effect of the wind when blowing
in the direction of the artificial strciim answering to the Gulf Streaan produced as
above described. The obli(]ue strip, corresponding the lower surface of the Gulf
Stream, then approaches the horizontal, i.e., the Archimedean forces in the current are
here highly weakened, and contribute only in a very slight degree to propulsion of the
water. As a matter of fact, the strip can, by sufficiently increasing the force of the
wind, be made to slope the opposite way, when the Archimedean forces will actually
oppose the progress of the current. On the other hand, with a wind in the opposite
direction to that of the current, as shown in the lowest diagram, fig. 45, the slope is
increased, the Archimedean forces being then greatly augmented.

The meaning of this is not difficult to comprehend. The hot centre W produces
a certain quantity of warm water, and the cold centre K a certain amount of cold
each second, quite independently of the wind. By adaptation, consisting of change
in temperature, a state of things is soon reached when the cold centre consumes warm
water and produces cold at a rate per second exactly corresponding to the rate at
which the warm centre consumes the cold and produces warm. The quantity of water
flowing per second through any section of the current will be exactly equal to the
amount of water thus transformed. Whether the current be subjected to the action
of the wind or not, this quantity of water must flow on. In the case shown in the first
diagram, fig. 45, the current is opposed only by the internal friction of the water itself,
and the Archimedean forces have here only this resistance to overcome. In the second
case, the progress of the current is aided to a high degree by the action of the wind.
The result of this is, at first, an acceleration of the current; this, however, soon causes
the oblique stratum to take up a more horizontal position, in consequence of which,
the Archimedean forces are so diminished that their motive power only suffices to
propel the requisite quantity of water when aided by the action of the wind. Finally,
in the third case, where the forward movement of the water is greatly hindered by the
wind, the current is at first retained, then, with the consequent increased slope, the
Archimedean forces attain a higher degree of intensity, until at last they furnish
motive power sufficient to propel the due quantity of water despite the resistance of
the wind.

From this we see how insignificant is the part played by the wind as a motive
power in currents of this nature.

11. BJERKNES' CIRCULATION THEORY.

The Bjerknes' theory of circulation, with the clear and profound insight which it
displays, is in my opinion so eminently valuable an adjunct to the study of hydrogra-
phical phenomena that I have thought it necessary here to give a general idea of the
principles contained therein, inasmuch as these bear directly upon marine conditions.
I have endeavoured, in this survey, to keep to the simplest iwssible mathematical for-
mulae only; readers wishing to follow the entire process of deduction and examine for
themselves the manner in which the results are arrived at, may refer to Bjerknes' own
works on the subject, in particular to his comprehensive treatise on dynamic meteor-
ology and hydrography, published by the Carnegie Institute, of Washington, U.S.A.

We may commence with Bjerknes' analysis of the Archimedean forces. As a
result of this analysis it is shown that the measure of the forces in question may be
taken as represented by the number of parallelograms formed in a hydrographic section
by the intersection of the isobars with the isosteres. It is here presupposed that the
figures in question are drawn for each whole unit of pressure or specific volume. Each

264

DEPARTMENT OF THE NAVAL SERVICE

sucli parallelogram endeavours to bring about a rotary movement of the water, whereby
the isosteric lines would be brought into the horizontal, vide fig. 40.

Fig. 4(1. — Bjerknes' diagram of the
Archimedean forces in the sea.

It is interesting to pursue the study of this simple geometrical diagram so as to
embrace the three dimensions. We have, then, in place of the isobars and isosteric
lines shown in fig. 46, a series of isobar and isosteric surfaces, while the parallelograms
become tubes, each presenting a parallelogram in section, these striving to turn the
water round in such a manner as to render the isosteric surfaces horizontal. As the
isobar and isosteric surfaces cannot terminate in the water itself, but must continue
until they reach either surface or bottom, so also the isobar-isosteric tubes formed by
intersection of the two must either continue until they reach one limit of the water
or else turn back upon themselves. As each tube lies between two adjacent isobar sur-
faces, its course becomes horizontal.

These isobar-isosteric tubes are called solenoids. Each solenoid produces the same
whirling effect in the water, and the number of solenoids is therefore a measure of the
degree of intensity attained by the Archimedean forces.

The number of solenoids depends upon the number of isosteric surfaces; i.e., upou
the stability of the sea-water, and upon the obliquity of the isosteric surfaces them-
selves. As the isosteric surfaces fall into a horizontal position, the solenoids disappear
entirely. Consequently, the greater the stability of the water layers, and the greater
the obliquity of the isosteric surfaces, the greater will be the number of solenoids.

Fig. 47. — Solenoids in the separating surface
between two water layers.

Where a homogeneous water layer rests upon another of higher specific gravity,
there will be no isosteric surfaces within the layers; such will, however, be found in
the separating .surface between them. In this boundary surface, then, the solenoids will

CAXADiAX nfiiii:ini:s nxruuriox, ioi.',-io

265

be located, vide fig. 47. It is easy to find the mimlier of solenoids in this caso. If the
.specific volume of the upper layer be vi, and that of the lower ro, there will then be
vi — vo isosteral surfaces in the boundary surface. And if the pressure at the lowest
point of the boundary surface be pi, that at its uppermost point po, then these isos-
terical surfaces will be intersected by pi — po isobaric surfaces. The number of solenoids
A will thus be .4 = (pi — po) (vi — ro) where pi — po indicates the slope of the isosteric
surfaces, and vi — I'o the stability of the water layers. The number of solenoids is the
product of these two factors.

In order to ascertain the effect of the solenoids upon the movement of the water,
Bjerknes takes a closed curve composed of water particles in the sea, and calculates the
product of the curve's length and the mean velocity of the wat:^r along its '^ourse This
product is called the circulation of the curve. Where the velocity of the water is not
uniform at all parts of the curve, the circulation may be most easily arrived at by
integrating the tangential velocity of the water along the curve for the whole length of
the same.

C

/"■

ds.

(4)

This integration may best be represented graphically by setting out the length of the
curve, reckoned from any point, in a rectangular co-ordinate system, as abscissa, with
the tangential velocity of the water as ordinates, and then, by means of a planimcter,
measuring the extent of the surface between the curve thus produced and the
abscissal axis. Fig. 48 shows the application of this method for calculating the cir-
culation of a circular curve situated in a current. The current is here taken as flowing

Fig. 48. — Motliod of calculating the circulation in a closed circulation curve in a sea current.

horizontally, at the velocities shown in the diagram on either side of the figure. The
curve is first divided up into a suitable number of parts. At each point of division,
the velocity of the water is marked off', and its tangential component along the curve
constructed. In the diagram at the bottom of the figure, the length of the curve
reckoned from the point 0 is set off as abscissa. At the points 0, 1, 2 of the abscissa,
corresponding to the similarly designated point on the closed curve, the tangential
velocities are thereafter marked oft" as ordinates. The area of the diagram is then
measured with the planimeter, the part below the abscissa being of course taken as
negative, and subtracted accordingly ; this gives the circulation of the closed curve.

6551—21

266

DEPARTMENT OF THE NAVAL SERTICE

If we divide the circulation thus arrived at by the length of the curve, we obtain
the mean tangential velocity along the closed curve. By marking this off on the dia-
gram, we obtain in the horizontal line there dividing the same into two parts, so that
the area above the line is equal to that below.

This mean tangential velocity may now be again applied to the original closed
curve. Circle No. 2 in fig. A8 shows what is then arrived at, viz., the rotary movement
of the water.

The circulation of closed curves in the sea thus affords a measurement of the rota-
tion of the water. Tlie translatory movement in the water is not discernible in the
circulation. A closed curve in a current, where all the particles have the same velocity
will always have a circulation = 0. By calculating the circulation, we thus obtain the
pure rotary movement of the water, vide fig. 48.

Fig. 49. — Relation between solenoidti
;uid circulation.

It now only remains to find the relation between the circulation C, and the number
of solenoids A. To arrive at this, we lay out a closed curve in the section, fig. 46
(vide fig. 49), and calculate the circulation in the manner shown in fig. 48. This
gives a certain value, C. This value is, however, not invariable, but is continually
augmented by the rotary tendency of the solenoids. According to Bjerknes, the increase
of circulation per second is equal to the number of solenoids within the closed curve.
After the lapse of t seconds, therefore, the circulation of the curve will be

C = Co + At

By derivation we then obtain,

d C

dt

A

(5)

indicating that the increment of circulation per second is equal to the number of
solenoids. By means of Bjerknes formula for the relation between distribution of
density in the sea and movement of the water, we can thus in the easiest possible
manner calculate the latter from the former.

Obviously, the circulation is affected, not only by the distribution of density, but
also to a very high degree by the earth's rotation. Each latitude circle of the globe
has a considerable circulation owing to the earth's rotation. By a simple calculation,
this will be found to be C = 2oj*S' where to is the angular velocity of the earth, and 8
the area of the latitude circle. Bjerknes has shown, however, that this formula applies
equally to any closed curve on the globe, if we take 8 as indicating the area given by

CANADIAN FlhillElUE^ EXPEDITION, U)l',-l.j 267

projection of the curve upon the equatorial plane; and, further, that the alternation
in the circulation of such a closed curve per unit of time amounts to

dC _ dS
It -^'^ ~dt

wnere ^indicates the alternation per second in the area of the curve's projection

upon the equatorial plane. Where S is reduced, the curve assumes a cyclonic circula-
tion, while when S is increased, the circulation will become anticyclonie.

Finally, the circulation is also influenced by the friction. For the effect of this,
Bjerknes has introduced the symbol li. As both the earth's rotation and the friction
as a rule oppose the distribution of density, Bjerknes gives the influence of both a
minus sign, and writes

dC dS

dt di

This formula contains all that influences the circulation of the water in the sea.

dt =^'-'-^ li -'' («)•

12. SOLENOIDS IX THE CAXADIAX ATLANTIC AKEA.

Bjerknes' circulation theory will, it may safely be said, play a prominent part iu
future oceanographical investigations, on account of the ease with which it may be
applied to hydrographical observation material, and the clearness and direct practical
value of the results thereby obtained.

Its chief importance in the immediate future will be as a system upon which to
order and arrange the collecting of oceanographical observation material. The system
re(]uires, in this respect, certain conditions, of which those concerning the distribution
of density and specific volume have been excellently fulfilled by Dr. Hjort's measure-
ments in the Canadian waters, while those concerning the distribution of velocity
have as yet proved impossible of realization.

I purpose, then, in the following pages to apply Bjerknes' circulation theory, as
far as can possibly be done, to the present material, drawing such conclusions as may
thence be arrived at, and finally indicating what yet remains to be done in order that
the syiitem may be utilized to its fullest extent, and by the gradual adaptation of
measuring instruments, methods of observation, etc., directed towards the solution of
still further oceanogTaphical problems.

The weak point in the methods of observation hitherto in vogue is the system
employed for measurements of velocities. Bjerknes' theory demands two kinds of

ds

measurements in this respect: one for the calculation of 2<o -rr and the other for

di

that of Tl. An instrument for the former already exists,^ and all that remains here
is to arrange the observations in such a manner as to render them suitable for the
Ijurpose of calculating the influence of the earth's rotation according to Bjerknes'
theory. For the latter calculation, we have no suitable instrument as yet; it is, how-
ever, an easy matter to construct one, and to arrange the observations so as to furnish
the requisite material for calculation of B.

As regards A, the material collected by Dr. Hjort from the Canadian waters is
in this respect beyond question the best that has ever been obtained from the atmos-
phere and the sea. Hjort's idea was to procure the fullest iX)ssible survey of hydro-
graphical conditions, spring and summer, in the North Atlantic area, and this, as it
proved, coincided entirely with Bjerknes' requisition as to get two complete and simul-

1 Hans Pettcrson. A recording current meter for deep sea work. Quarterly Journal
of the Royal Meteorological Society, vol. XLI, No. 173, January, 1915.

6551—21.^

268

DEPARTMENT OF THE NATAL SERVICE

taneous surveys o£ density conditions in the area. From a dynamic point of view,
Hjort's measurements leave absolutely nothing to be desired.

In applying Bjerknes' theory to hydrographic observations, it will be well to keep
to one thoroughly connected system of units, as, for instance, the centimetregrammese-
cond system. Where these units do not suit, other convenient units can always be
arrived at by multiplying by suitable powers of 10. Pressure in the sea increases by
very nearly 100,000 c.g.s. units for every metre depth. If therefore, we take as unit of
pressure of 10'^ c.g.s. then the pressure will increase by one such unit for every metre
depth. Such iinit of pressure we may call a decibar. To the pressure of the sea-water
should be added that of the atmosphere, amounting to about 10 decibars. In the follow-
ing, however, we shall not have occasion to reckon with absolute pressures, but only with
differences of pressure, and (may therefore neglect this initial pressure, taking the
pressure at the surface of the sea as a starting point. The depth in metres will then
likewise serve to express the pressure in decibars; thus at 10 metres' depth, the pressure
is 10 decibars, at 300 meters, it is 300 decibars, and so on. This identity of values will,
as we shall subsequently see, serve greatly to simplify the graphical and numerical
operations involved.

om.

100 -

200

500 -

400 -

V,= 500

V,=400

Fig. 50. — Isobars, isosters and solenoids in
section IX.

For specific volume, it is convenient to take 10-^ c.g.s. as the unit. Then instead
of writing, for instance, v=0-97261, we take 10^ v=97261, and as the two first figures
in values for specific volume are always 97, and we have only to reckon with differences
of the same, we can discard these, and write v== 261. Thus in the case of specific
volume, we have only to deal with three-figure values, which again serves to render the
necessary calculations easier.

By thus taking the isobars as 10^ times too far apart, and the isosteres 10^ too close,
we obtain cgs. solenoids.

CAH^ADIA^ FISHERIES EXPEDITION, lOl-i-lo

269

Fig. 50 shows isobars, isosteres, and solenoids in section IX. The isobars have
been drawn for each ten metres depth, and the isosteres, for each tenth unit of v. In
fig. 50, th?n, each square contains 100 cgs. solenoids.

If now, in the isosteric sectons I-XX, plates VIII and IX we work out in a
similar manner the isobars for each 1 metres depth, we obtain a good view of the
distribution of the solenoids and their number throughout the entire area of investiga-
tion. Where the isosters have been drawn for each tenth unit of v„ each square will
contain 100 solenoids, but in the upper parts of the section, where they are taken for
each fiftieth unit of i\, there will be 500 solenoids to the square. It should hardly be
necessary, however, to draw up in practice a linear system so simple as that of the
isobars for each 10-metre depth; this may easily be imagined. On so doing, we obtain

53 3^ 35

36

0 fn.

1

y • «i»inl««»« • y^

•

\» • ••••••••«• tf

V I • /

" s

N. • •• •••• ^^.^^^

)

\ e •• ♦ •

J

\* • • • a

/

\« • • •

• •

\ ■ • • •

•

\ • • 0 •

• •

100

\ • • • • •

• • •

\ • • » •

• • •

\ • • • t> •

• • •

\ • • • '^"^ •

• • • •

\ .' .*.*.'.*•

\ • • • •

\* •••e*a

1 • • • •

\Q..1^200.

05^9®

\« •••»• •

• • •

»••*••• •

• • •

200

y.*/.v.\*

!•••••• •

• A •/

I • • • • •

• 1

j* • • • •

• 1

U • • •

I

I • • •

1

1 • •

/

300

r * *

• 1

\* *

•1

\ •

1

\ •

1

\ •

1

\ •

1

400

\A

/

\ •

•i

Fi^. 51. — Solenoids in section IX.

from the isosteric sections I-XX, an immediate idea as to the position of the sole-
noids and their numerical values during spring and summer in the Canadian waters.

Another good way of showing the number and distribution of the solenoids is as
follows: After drawing up the isobars, and isosteres, the ix»ints of intersection between
them are marked out. and both line systems then erased. This gives a system of points,
each representing 100 solenoids. By counting the points, and multiplying their
number by 100, we obtain the number of solenoids {vide fig. 51).

Each solenoid lies between, and is bounded by two adjacent isobar nurfaces. Its
course is thus pefectly horiz()ntal, and its vertical extent amounts to exactly one

270 DEPARTMENT OF THE NAVAL SERTICE

lenetre. Its breadth is considerably greater, being equal to the horizontal distance
between the isosteric surfaces. And as it is always bounded horizontally by the same
isosteric surfaces, its course may be arrived at by drawing upon a chart the isosteric
lines for the level at which the isosteres are situated. This chart will then also give
the course and number of all other solenoids in a water layer of one metre's thick-
liess at the same level.

Iliere are thus many ways of drawing up graphic presentments of solenoids.
We need not, however, here devote more time to these, but may pass directly to the
problem of calculating, in the simplest and surest manner, their number, A. The
number of solenoids between two stations in a horizontal water layer of one metre is
obviously equal to the difference in specific volume between the two stations at the
level in question. Our first task, then, will be to calculate this difference. Let us,
for instance, calculate the solenoids between the stations 34 and 35 in section IX.
First of all, we note down the depth at which the water samples from each station
were taken. This is shown in the first column of table 3. The second column shows
the specific volumes for station 34, and the third those for station 35. The fourth
column contains the differences between the specific volumes; i.e., the number of
solenoids in a water layer one metre thick situated between the two. The signs!
before the figures shows the rotary tendency of the solenoids. In the vertical, with
greater specific volume, the water will strive to move upwards; where it is less, the
tendency will be downwards. The solenoids will thus endeavour to bring about such
a rotary movement of the water as should cause it to rise at station 34 and sink at
station 35. This is what the signs here show. The signs have thus a certain relation
to the order in which the stations appear in the tables. If the stations be reversed,
the signs will be changed.

The next operation is to calculate the number of solenoids in those rectangles in
the sea which are bounded by the two stations and the different depths. For this pur-
pose, we calculate, from the figures in column 4, mean values for 1-metre water layers
at the different intervals of depth. These are shown in column 5. Multiplying by the
depth of the intervals in metres, we obtain the desired number of solenoids, as shown
in column 6. By this simple and rapid means, it is possible to calculate the number
of solenoids between any pair of stations in the area where observations were carried
out simultaneously, or nearly so, however great may be the distance between the
stations. The number of solenoids between a station in the Arctic and another at the
equator may be calculated as easily as the corresponding value for two stations in the
gulf of St. Lawrence. And this is just one of the features which render Bjerknes'
circulation theory so useful in discussing the greater phenomena of the sea.

If the two other pairs of stations in section IX, 33-34 and 35-36, be treated in the
same manner, we shall then have obtained all the solenoids in section IX, which can
be found from the hydrographical observations there carried out. Fig. 52 shows the
number of these, and the areas within which they are found. Here, then, we have yet
another method of presenting solenoids. Of the various methods in which this can
be done,those shown in figs. 50 and 51 are clearer, but that in fig. 52 is more correct.

By the method shown in table 3 and fig. 52, we obtain only the solenoids which
are found between the hydrographical stations, but not those lying outside. For the
latter, the methods shown in figs 50 and 51 are more convenient, permitting, as they
do^ extrapolation so as to include also the area outside the stations. This extrapola-
tion method cannot well be applied to the more exact procedure shown in fig. 52. The
extrapolated values might also be of so little value as to leave no reason for preferring,
on this account, figs. 50 and 51 to fig. 52. The numerical method shown in table 3
should therefore be regarded as the best way of arriving at the number of solenoids.

On adding up the figures in column 6 of table 3, we obtain the total number of
solenoids between station IX 34 and IX 35. The addition may be made either from
above or from below. The latter is preferable, the water at greater depths being as a

CAXADIAX FISHERIES EXPEDITIOX, lOl't-LJ

271

rule calmer, with fewer solenoids. It is therefore advisable to commence from below,
with O, and then let the perturbations in the upper water layers appear through th^
greater number of solenoids there present. The lowest level from which measurements
are available will then be the starting point, and the number of solenoids will be shown
as from this level to all levels above. Column 7 in table 3 shows the sums of the
solenoids.

om

100 -

200-

300

400-

Fig. 52. — Amount of solenoids in section IX

Obviously, the number of solenoids as thus calculated will depend upon the dis-
tance between the stations. The farther one station lies from another, the greater will
generally be the number of solenoids found between them. In order to obtain a cor-
rect idea as to the solenoid intensity in the sea, it will therefore be best to reduce the
number of solenoids to a certain normal horizontal distance, e.g. 100 km. The distance
between station 34 and 35 in section IX is 62 km. By multiplying the number of sole-
noids by 100 and dividing by 62, we obtain the normal values for this particular case.
This operation should be carried out with the figures in columns A and 7 of table 3.
Columns 8 and 9 contain these normal values. The figures in column 8 show the num-
ber of solenoids in 1 metre layers for 100 km., i.e. affords a measure of the variation in
density in a horizontal direction, and column 9 the number of solenoids per 100 km.
from the different levels of measurement down to the greatest depth from which observ-
ations are available. The figures in column 8 furnish the best means of indicating the
intensity of the Archimedean forces in the section, while those in column 9 best show
the effect of the forces in question.

Coming now to the question of publishing these different values for the number
of solenoids between all pairs of stations in Dr. Hjort's sections, we may begin with

272 DEPARTMEXT OF TEE XATAL SERVICE

eliminating the first two columns of table 3, thefie being contained in table 1.
Cohmins 4 and 8 are left unaltered, column 5 is superfluous, and in columns 6, 7,
and 9, the last figure of each value should be discarded, partly as having no real
importance, and partly as rendering the values in question unnecessarily awkward
to handle in calculation. This done, the solenoids in these columns are expressed in
10 cgs. Column 9 may also be said to indicate cgs. solenoids per 10 km. Table 4
shows the simpler form given to table 3 by this process. Table 5 contains the
number of solenoids according to the scheme in table 4 for all pairs of stations in;
Dr. Hjort's sections. The heading above each pair of stations indicates the distance
between them, and the approximate mean depth of the intervening area.

13.— INFLUEXCE OF THE EAKTH'S EOTATION UPON" CIRCULATION.

The influence of the earth's rotation upon circulation makes itself apparent in a
very simple manner in the atmosphere. When the air at any point commences to
rise upwards, and the surrounding air in consequence pours in from all quarters to
replace that which has risen, then this indrawn air will, as it approaches the centre of
ascent, develop a marked cyclonic circulation. Thus in fig. 53, taking 0 as the
centre of ascent, and ^1 as a closed curve composed of air particles about the same,
then, at the commencement of the movement, the velocity will be directed towards
the centre, and the curve will have no circulation. After a certain lapse of time, the
curve will, on account of the centripetal movement of the air, have contracted to
the position h, at the same time developing a cyclonic circulation. The circulation
increment per second is, according to Bjerknes: —

¥ ~^'" dt ^'^

oj being here the angular velocity of the earth, and S the area of the closed curve's
projection upon the equatorial plane. And as S decreases, C is increased, vide fig. 53.

Fig. 53. ^Cyclonic circulation pro-
duced by the earth's rotation.

In the sea, the movement of the water is to a very high degree restricted and
deformed by the shape of the water basins. There is, therefore, in this case, no
regular concentric movement about the centre of descent. In spite of this, however,
we still find here a marked cyclonic circulation, which, in the Arctic ocean, where
the Gulf stream sinks doAvn, and in the waters south of Newfomidland, where the
Labrador current disappears, attains very considerable dimensions.

The vertical velocities in the sea are insignificant in comparison with the
horizontal, and we may therefore, in calculating the circulation, neglect the former

CANADIAN FISHERIES EXPEDITION, lOl'i-lo 273

altogether. We then obtain the area S of the projection of the closed curve upon the
equatorial plane, by pro.iectinjr the curve u]ion the level of the surface of the sea, and
multiplying the area a thus obtained by the sinus of the latitude*^ i.e.,

iS = a sin If) ■■'

Inserting this value for S in -(7), we obtain

dC da

dt ^"' dt

V

And if, again, we insert in this formula the value for 2 oj, viz., 0.0001458, we obtain

d C da. ,^^

—- = — 0.0001458 -y- sm ^ (8)

d t d t

This formula (8) is specially suited to the treatment of measurements of velocity in
the sea, as these measurements always give the horizontal components of the velocities;
i.e., the projection of the direct velocity upon the level of the sea's surface.

No measurements of velocity were made during Dr. Hjort's expedition in the
Canadian waters, and we have therefore no opportunity of applying the Bjerknes' for-
mula for rotation of the earth to observations here in the regular manner above
described. We have therefore recourse to another, more indirect application of the
same, we can reckon out the velocities which the water should have in order to fulfil
the requirements of Bjerknes' equation, with the distribution of density as found by
Dr. Hjort. By this means, we obtain indirectly an idea as to the movement of the
water within the area of investigation.

In Bjerknes' equation (6), the first and last terms are small in comparison with
the two intermediate ones. As a first approximation, therefore, we may disregard the
former and write

^-'- -dt-
or, instead of this, taking the projection of the closed curve upon the level of the sea

A = 0.0001458 — ^ sin ^
dt

From which we obtain

dt 0.0001458 sin <r,'

(9)

In this formula, the right side is determined by the distribution of density, and the
left by the movement of the water. The right side is known from table 5, which shows
A for a large number of closed curves throughout our area of investigation. In con-
sequence, therefore i.e., the deformation of these curves, due to the movement of

d t

the water, will likewise be known. By this means, we are able to calculate the move-
ment of the water from the distribution of density.

Obviously, however, we cannot by this means obtain the whole movement of the
water. We might imagine, for instance, a closed curve composed of water particles in
a current, following the current in such a manner that the area of its projection upon
the level of the sea's surface would not be altered thereby. This would, then, according
to formula (9), contain no solenoids at all. But this does not necessarily imply that
the water in whic"h the curve appears, and of which it forms a part, has no great
velocity. In other words, the formula (9) gives, not the absolute velocity of the curve,
but only its deformation, i.e., the extent to which its one part moves relatively to the
other.

The closed curve should therefore be selected in such a manner as to give the least
possible degree of movement in the one part. As equation (9) gives the movement of

274 DEPART31ENT OF THE NAVAL SERVICE

the other part relative to this, it will in this case give the actual velocity of the same.
Now, the movement of the water at great depths is inconsiderable, the greatest velo-
cities occurring in the upper water layers. We therefore select the closed curve in
such a manner that its one part is situated at the greatest possible depth, and calcu-
late the velocity of the other, upper portion, relatively to this deeper part.

The values in table 5 best suited to this calculation are those indicated as 2 A ,0^^-
This column gives A for closed curves having their vertical parts situated at a dis-
tance of 10 km. apart and with the one horizontal portion situated at the greatest
depth from which measurements are available. Taking this lower horizontal portion
as immobile, and the upper as moving at right angles to its own longitudinal direc-
tion with a velocity of a cm. per second, then obviously the increment of area in the
projection of the curve upon the level of the sea's surface amounts to

d<j

— = 10" M

dt

da
per second, 10 km. here representing 10^ cm. Inserting this value for — in (9), we

dt
obtain :

A

u = (10)

l-A.'^-R sin (p

For the latitude = 43° 19', which falls within our area of investigation, is

145-8 sin ^p = 100
and in consequence :

A

n = — (11)

100

i.e., the 2 A lOum- columns in table 5 give the velocity in hundredths of a cm. per
second. We need then only cut off two decimal points from the figures in this
column in order to obtain the velocity in cm. per second.

In order to comprehend what is given in formula (11) we may consider a cur-
rent in the sea flowing over a substratum of still water. Owing to the rotation of
the earth, the current will veer off to the right until it encounters a coast, which)
it will then follow, still pressing towards the right, i.e., setting in towards the coast.
In consequence of this pressure, the current will become deeper near the coast than
farther out; i.e., the separating surface between the current and its substratum of
heavier water will lie obliquely. In this surface, then, there will be a number of
solenoids running in the longitudinal direction of the current. By taking a hydro-
graphical section across the current, and treating the observations according to the
scheme in table 3, we obtain the number of these solenoids. Formula (11) now
shows, that if 10 km. breadth of current contain 100 solenoids, then the current will
flow at a velocity of 1 cm. per second; if 1,000 solenoids, the velocity will be 10 cm.
per second, and with 10,000 solenoids, the velocity of the current will be one metre
per second. If the number of solenoids be 6,728, the velocity of the current will be
67-28 cm. per second.

This simple relation is, of course, strictly speaking, valid only for latitude 43° 19'.
For other latitudes, we can obtain from table 6 the number of solenoids per 10 km.
breadth of current which will give a velocity of 1 cm. per second. By dividing the
values for number of solenoids obtained through the hydrographic measurements by
the figure in table 6 ccirresponding to the latitude of the station, the due allowance for

CAXADIAN FISHERIES EXPEDITIOX, ]D1',-15 275

geogTaphieal situation will 1)(^ ina<le. The last column in table 5 contains the velocities
thus calculated.

As regards direction of the current, this will be easily understood from the fore-
going'. The lighter surface water is pressed over to the right by the earth's rotation.
Placing myself, for instance, in the section so as to have the lighter water on the right
hand, and heavier on the left, I am then facing in the forward direction of the cur-
rent.

It will also be evident from the foregoing, that the method in question gives only
the component for current velocity in a direction at right angles to the section. This,
however, is in the present case of but slight import, as Dr. Iljort has for the most part
taken his sections in such a manner as to have them almost at right angles across the
currents found. J)r. Hjort's measurements are, from a dynamic point of view, ideal
in this respect.

In table 5, eight points of the compass have been used to designate the direction
of the current. As usual, in dealing with ocean currents, tlie letter indicates the direc-
tion towards which the current flows. Thus K, for instance, denotes a current flowing
from west to east.

Plates XIV and XV have been drawn U]) from the figures in the last column of
table .5. The former gives the calculated velocities for spring, the latter for summer,
1915. From the intimate relation of these velocities to the number of solenoids (vide
table 5), it follows that Plates XIV and XV also afford the best possible graphic pre-
sentment of the distribution of solenoids throughout the area of investigation.

14.— INFLUENCE OF FRICTION UPON CIRCULATION.

The influence of friction B upon the circulation of a closed curve, may be cal-
culated in two different ways; either directly, from measurements of velocity taken for
the purpose, or indirectly, by means of Bjerknes' equation for circulation, all the
terms of this being known with the exception of R.

In the former case, three uniform current meters are set out on one and the same
line, with say 5 metres vertical interval between each two, with which systems of
instruments measurements are then taken at the different depths. From the measure-
ments thus obtained, the parabolas for diagram of velocity are then constructed, and
from these again the acceleration of the frictional force can be calculated (chapter 9).
By integration of the tangential component for this along the closed curve, we obtain
JR.

In the second case, we have, according to (6),

d S dC

dt dt

dC ^. , .

When the movement is stationary, — j-— disappears, and we have,

d t

d t

If the closed curve lies along a stationary current, then 2oi _i_ will likewise di-;-

dt

appear, and we olitain

K = A (13)

276 DEPARTMENT OF THE XATAL SERVICE

With this formula, it is a very simple matter to calculate the influence of friction
upon the circulation, as also the acceleration of friction in a stationary current. As
an example, we may take the Gulf Stream. A closed curve along this will include
150,000 solenoids, and consequently, in the Gulf Stream the retarding influence of
the friction upon the circulation will amount to

cm
B = 150.000 — =-

On dividing this figure hy the length of the closed curve, 15-10^ cm., we obtain the
mean value for retarding acceleration of friction for all water particles in the Gulf
Stream,

/ = 0-0001^

As a second example, we may take a closed curve along the Gaspe current at the
surface, and at GO metres depth, between Dr. Hjort's stations X 31 and XIII 38. On
calculating A for this, according to the scheme shown in table 3, we find that the
number of solenoids is 10880. For this, again, according to (12),

cm "^
M = 10880 -^

sec.

The length of the closed curve, via Xorth, Cape Breton island, amounts to 2-10^, i.e.,

/ = 0.00005 -^^
sec.2

It is surprising that the retarding effect of friction upon ocean currents should
be so great as this. If the solenoids ceased to operate, then the velocity of the Gulf
Stream would be diminished by 1 cm. per second per 3 hours, and the Gaspe current
by 1 cm. per second every 6 hours; in other words, save for the solenoids, currents of
this nature would soon come to a standstill. We realize, then, the fundamental im-
portance of the solenoids for propelling ocean currents.

If the closed curve be drawn across a stationary current, then R disappears, and
(12) in consequence, gives place to

2o. ^ = A (14)

a t

by means of which formulae ^we can calculate the movement of the water from
the solenoids, see table 3 and plates XIV and XV.

These two formulas (13) and (14) are, as hydrography now stands, the most im-
portant mathematical means for dynamic treatment of hydrographical observations.

In applying these formulae, it is necessary to see that the conditions for which
they are intended to apply are fulfilled. One disturbing factor which has to be
reckoned with is the screwing movement of the water in a current. Owing to this,
the influence of the earth's rotation does not altogether disappear in the case of
closed curves lying in the longitudinal direction of a current. The part of such
curves which is situated at the surface, is, by this screwing movement, carried towards
the right, and we may easily find that the earth's rotation will therefore exert a
retarding influence upon the current. The retardation calculated by formula (13),
therefore, should not be ascribed exclusively to friction, as a part of it will be due
to the earth's rotation. The more stable the layers in a cui'rent are. however, the

CANADIAX FISUERIES EXPEDITION, J'Jl'rlJ 277

less chance will there be for tiiis screwing movement of the water to develop, and the
iii'A-e insignificant the correction of formula (13) owing to rotation of the earth.
On the other hand, where the water in a current is homogeneous, the screwing movement
will develop to a greater degree, and there is then the risk that formula (13) may give
too high values for R.

Formida (14) will likewise require to be corrected for the same reason. The
screwing movement of the water is naturally opposed by the friction, and the influence
of the friction upon the cii-culation does not therefore altogether disappear in the
case of closed curves drawn transversely across a current. In such curves, then the
earth's rotation will have two forces to overcome; that of the solenoids, and that of
the friction. Thus the velocities calculated according to (14) from the solenoids
alone will be too low; i.e., the values for velocity given in table 5 and plates XIV and
XV will be too small. The friction, on the other hand, will have no effect upon their
direction. By increasing these calculated velocities slightly, they can thus be made
more (.correct viz., the less stable the water layers are the more the velocities will
require to be increased.

The most disturbing influence, however, which affects the velocities calculated
from formula (14) is that of the wind. The friction exerted upon the surface of the
water by wind corresponds to a very considerable value of R. This will naturally
be variable to a very high degree, but the direction in which it takes effect, and its
nature generally, will of course depend rather simply upon the direction of the wind.
By taking a few simple cases as examples, we may gain some idea as to the effect of
wind upon the distribution of density in a current, and the velocities thence obtained
according to formula (14).

(a) Wind blowing in the forward direction of the current. — In this case, the velo-
city of the surface water will be increased, and the water in question consequently be
thrown off with greater force than previously to the right. In a section across the
current, the isostercs will become more vertical, and the number of solenoids. A,
greater. The calculated velocities will thus become greater, which agrees with the
increased velocity due to the action of the wind. In this instance, then the effect of
the wind will not greatly disturb our calculations according to (14).

(fe) Wind Itlotving directly against the current. — The surface water will here be
retarded, and the force with which it veers off to the right will be diminished. The
number of solenoids in a section across the current will be less, and thus the velocities
calculated from the same will likewise be lower, agreeing, again, with the actual
decrease in velocity due to the opposing action of the wind. In this case also, then,
the disturbing influence of the wind upon the calculations according to (14) will be
but slight.

(c) Wind hlowing crosswise to the current, and in a shoreward direction. — The
surface water is here driven with great force to the right; the isosteres stand on end,
and the number of solenoids in a section across the current will be abnormally increased.
The velocities calculated fi-om the solenoids according to (14) will therefore here be
too great.

(d) Wind hlowing crosswise to the current, in a seaward direction. — With a slight
wind, the number of solenoids will be reduced, and the velocities thence calculated
according to (14) too low. "With a stronger wind, the entire current may be forced
away form the shore and out to sea. This gives rise to a highly abnormal distribution
of density and of solenoids, vide fig. 54 a, which on applying formula (14) gives the
distribution of velocities shown in fig. 54 b. This is here so abnormal that it does not

278

DEPARTMENT OF THE NATAL SERVICE

correspond in any way to the actual movement of the water. Dr. Hjort's section IV
is a good example of such abnormal distribution of density.

By simple discussions of this kind one may soon become familiar with the various
phases which the state of the sea may assume, and can thus learn to determine the
causes by which they are produced.

Fig. 54. — Distribution of density and cal-
culated velocity according to formula
(14) with offshore wind.

15. THE ACCELERxiTION OF CIRCULATION.

Let us imagine the sea and atmosphere in perfect calm and equilibrium. The
isosteres and the isobars coincide with each other, and with the level surfaces of gravity,
so that no solenoids exist.

In a part of this motionless sea, some physical i^rocess then takes place, whereby
the specific gravity of the water there is altered. This gives rise to a local deformation
of the isosteric surfaces, which now no longer coincide with the isobars, but intersect
the same. The solenoids thus called into play then set the water in motion, according
to the formula

dC
dT

= A

At the commencement of this movement, therefore, the acceleration of the circulation

d C

—- will be equal to the number of solenoids.

d t

As the velocity of the water increases, the resistance of friction R makes itself

apparent. We have then

dC
~dT

A—R

There R increases more and more, until at last it equals A. Then, according to the

formula, — ^ — disappears, and the movement becomes stationary. This is the sign of
d t

permanent currents, originating in and maintained by a i)erpetual physical change

taking place in the sea water, such as the Gulf Stream.

CA\Al>IAy ri^UERIEH EXrEDITlOX, 1<>1',-15 279

The earths rututiuii, huwevcr, also exerts a certain iullueuec ujiun the circulation
of the water. When the solenoids have set the water in motion, it is forced over to the
riffht by the rotation of the earth. This pressure is augmented as the velocity of the
water increases. Consequently, the rapidly moving surface water in a current is urged
more forcibly to the right than the slower-moving water at greater depths, so that the
total movement of the water mass will be a screwing one. And a transverse section
across the current will therefore reveal a circulation taking i)lace within the same. For
this, the acceleration of circulation will be

d (' d S

dt dt

Tliis circulation is itself opposed by the friction, wherefore

d C d S

= 2aj -r^ — R

dt dt

As the circulation is increased, the opposing force of the friction will likewise be aug-
mented, until the influence of the latter will attain a magnitude equal to that of the

dC
earths rotation. Then will disappear, and tlie circulation become stationary.

If the water of the current be in stable layers, then a system of solenoids will arise
in the section across the same, and will, like the friction, oppose the influence of circu-
lation occasioned by the earth's rotation. In this case, then,

dC dS ■ ^ ,^

d t ""^ d t

' Where the water is very stable, these reactionary solenoids may altogether arrest
the circulation in the cross section. Then B will also disappear, and we have

dC dS

-J- = %, -j-^ A

The number of solenoids increases imtil it attains the same value as the influence of

d C
the earth's rotation, whereby disappears, and a stationarv situation sets in. It

d t

is on such a state of things that rates XIV and XV have been based.

d C

In all the cases here described, the acceleration of circulation increases

d t

rapidly at first from its value nil when the sea is at rest, reaches a maximum, and then
declines asymptotically towards nil, when stationary conditions are reached. Fig 55a

, , . . . . d C . ,. .

shows this varuitioji oi — — m course of time.
dt

If the physical change in the water which gave rise to the current be of temporary

nature, then the number of solenoids thus produced will gradually decrease, the current

meanwhile progressing by inertia. The effect of friction will then l)e superior to that

d C
of the solenoids, and — — will be negative. As the pliysical changes graduallv cease,
at"

the final state will in this case be that of calm and equilibrium. Fig. 55b shows the
variation in the acceleration of circulation for a casual and temporary current of this
nature.

280

DEPARTMENT OF THE NATAL SERVICE

It may also happen that the water, through inertia, flows too far. This gives rise
to a system of solenoids the reverse of the original, and tending to turn the current,
and so drive the water back. If this reverse movement, in its turn, carry the water too
far, then a new solenoid system, corresponding to the original one, will again arise, turn-
ing the current once more in its original direction. This may be repeated several times.

Fig- 55. — Alteration of circulation ac-
celeration on the appearance of a) a
permanent current b) a casual and
temporary current.

The alteration in the acceleration of circulation will then become periodical, vide
fig. 56.

From the foregoing, it will be seen that the sea is continually striving towards a

dC

state where

dt

approaches nil, i.e. the three terms on the right side of Bjerknes cir-

culation equation endeavour to adapt themselves one to another in such a manner that
their sum shall be nil. This would also take place, were it not for the fact that one or
other of them is from time to time subjected to disturbance which alters its magnitude.
This disturbance may be of various sorts. A physical change in the water, as for in-
stance that brought about by the heat of the sun, or by the melting of ice, will alter the

dS
value of ^. If a current veers off owing to the topography of the sea basin, then 2w —

dt

will be altered. The action of the wind exerts a great influence upon R, etc. After

dC
each such disturbance -= — attains a maximum, decreasing afterwards, however,
dt

towards nil. Where the stability of the water layers is very great, as in the gulf of St.

dC
Lawrence, this decrease may take place so forcibly that — — - passes beyond zero and

becomes negative, thereafter altering periodically with decreasing amplitude, vide fig
56. The greater the stability of the water layers, the more rapidly will these oscilla-
tions take place.

Such oscillation also, of course, take place in the surface movement of the water,
and would appear to be particidarly frequent in surface currents occasioned by the
wind; also, other surface currents however arising from different causes, doubtless
oscillate in the same way. As the water at any point of the surface can, at a given

CANADIAN FISHERIES EXI'EDITIOX, 191.'rl5

281

Lc^uilib

num

Fig. 5G- -Submarine seiches occasioned by brief but violent gales.

C551— 22

282

DEPARTMEXT OF THE XATAL SERTICE

movement, have but a single direction of movement, it follows that the lines of cur-
rent for surface water must answer to the equation

d y

= f i,ry)

where x an y are the geographical co-ordinates of the sea's surface. For

sin {ax + by)
we obtain the courses of the current shown in fig. 57.

d y
d X

Fig. 57. — Oscillation of surface water, in area with water layers in stability.

The existing material of simultaneous measurements of velocity in the sea is unfor-
tunately too small to permit of our verifying the current course here obtained by
mathematical means. The meteorology is in this respect far more favourably situated,
owing to the large number of stations from which the direction of the wind' is obser-
ved simultaneously. And it is then a very simple matter to discover the existence of
such oscillations. Figs. 58 and 59 serve to illustrate this. Fig. 58 shows direction
and force of the wind, with distribution of atmospheric pressure on January 7, 19€2,
at 9 p.m. At a first glance, the direction of the wind would appear to be highly irre-
gular, not only in comparison between the various stations, but also when compared
with the regular course of the isobars. On drawing up the courses of the wind how-
over {vide fig. 59) we find that the directions taken by the wind form part of a high-
ly regular, and strongly oscillating wind system. Very much the same thing doubt-
less takes place in the sea. The observations of velocity, which at a first glance appear
most irregular, might possibly turn out to be in actual fact, very regular and uniform,
If only w^e could discern the oscillating system to which they belong.

Naturally, it will be out of the question to procure a network .system of stations
at sea as close as that for simultaneous observations on land. This would require too
great a number of vessels. It would seem reasonable to ask, however, if the facility
with which it is possible to ascertain conditions in a vertical direction in the sea,
might not compensate for the greater facilities on land in a horizontal direction.
Where the surface water, owing to the oscillating movement, is massed together, the
surface layer must be thicker than where it flows apart. It should be an easy matter
to construct an instrument for indicating, for instance, the depth of an isotherm
situated not too far down, while the vessel lay motionless at a hydrographical station.
If the depth be constant during the time the measurements are being made, then the
sea is not in oscillation, and the hydrographical observations may be taken as repre-
sentative of the place and season ; if, however, the dej)th varies, then periodical oscil-
lations take place, and the hydrographical conditions ascertained by measurements

CANADIAX FISHERIES EXPEDITIoy, lOL'f-iii

283

Fig. 58.— Direction ot wind on 7 January, 1902, at 9 p.m.

0551—22^

284

DEPARTMEISIT OF TEE NAVAL SERVICE

Fig. 59. — Courses of wind on 7 January, 1902, at 9 p.m.

CANADIAN FISHERIES EXPEDITION, 1911,-10 285

Avill be dependent upon tlie phase of the osciUation. The variation in the depth of the
isotherm gives this phase, and thus also furnishes a possibility of correcting for the
same . It is an unsatisfactory matter of fact having frequently been noticed that
liydrographical measurements repeated from the same station at a few hours' interval
may give entirely diiferent results, as well for velocity, temperature and salinity.

Obviously, these periodical oscilla<tions arel the exact opposite of stationary
conditions, and the solenoids thus arising {vide, e.g., fig. 56) cannot therefore be used
to calculate velocities according to formula (14). By so doing, entirely erroneous
velocities would be obtained, with serious breaks to either side. Such breaks are,
however an excellent indication of wave movements of this sort. The distribution
of velocity in the boundary between the Labrador current and the Gulf Stream,
vide plates XIV and XV, distinctly indicates that the sea is there in a state of violent
oscillation.

Observations as to ebb and flow, and the currents occasioned thereby, should be
treated according to the principles set forth in this chapter.

10. OX THE TOPOGRAPHY OF THE SEA'S SURFACE, THE DISTRI-
BUTIOX OF PRESSURE, AND TRAXSFORMATIOX OF ENERGY

IX THE SEA.

In order to illustrate further the enormous practical utility of Bjerknes' cir-
culation theory in oceanographical work, I will here briefly touch upon one or two other
examples.

Where a sea is in a state of perfect calm and equilibrium, all isobars and
isosteres therein will coincide with the level surfaces of gravity. Such a state of
equilibrium may be supposed to exist at great depths, so that the sea there would
exhibit the same pressure at the same level. We can then, by means of the differ-
ential formula for measurement of barometric height,

, vdp (15)

dz =

9

vvliicli is equally applicable to the sea, arrive at the topography of the sea's surface.
By integrating (15) from the surface down to the level of greatest pressure p„ from
which observations are available, we obtain

Pi

vdp (16)

9 J po

where z represents the height of the sea's surface above the isobaric surface p,. If
this calculation be carried out for several hydrographical verticals of measurement, wo
obtain the formation of the sea's surface p=Po relative to the isobaric surface
p=Pi, i.e., the actual topography of the surface of the sea.

Owing to the great variation in the depths of the sea, the calculation may in
practice best be carried out by reckoning the difference in height of the sea's surface
at adjacent hydrographical stations, taken in pairs, and subsequently setting out all
the results together in the form of a topographical map. According to (16), the
difference in height between two hydrographical verticals will be as follows : —

9 J \

1 /-P,

vj dp (17)

This integral operation is, however, identical with that carried out in tables 4 and 5.
Using the terms there obtained, we get :

1
2,— 2.= — 2A (IS)

9
i.e., we have here the data requisite for calculation of the topography of the sea's sur-
face, by dividing the number of solenoids by tlie force of gravity.

286 DEPARTMENT OF THE NAVAL SERTICE

Now table 5 contains values of 2 A not only for the surface of the sea, but also for
isobars at deeper levels. The topography of these is then obtained in the same manner
as that of the surface. We can thus, by the process here described, ascertain in the
slope of the isobaric surfaces, and so arrive at the distribution of pressure throughout
the entire portion of sea from which observations are available.

From the slope of the isobars, it is easy to ascertain the acceleration of the water.
The most simple formulation of the relation between these two magnitudes is that given
by Dr. J. Hann, viz., that the acceleration of the water is equal to that component for
acceleration of gravity which falls in the isobar surface. Popularly speaking, we mtiy
say that the water slides down the sloping isobar surfaces, and that this sliding move-
ment is practically frictionless.

This again, however, is as much as to say that the sea-water in such respect may
be likened to the water of a river, and we can also apply the well-known laws for the
flow of river water to the currents in the sea. As an example we may take the Gulf
Stream. In this case,

2 A = 150000
On inserting this value in (18) we find that the surface of the sea lies about IJ metres
higher in the Tropics than in the Arctic ocean. In other words, the Gulf Stream may
be regarded as a great river, flowing down from a higher to a lower level.

The Gulf Stream carries 25,000,000 tons of water per second. This, with a fall
of 1-5 metres, amounts to a force of 500,000,000 horse- power, which is the amount of
energy expended in the propulsion of the Guli Stream. It is utilized to overcome
friction, and is thus converted into heat.

If we now insert 2A=10880 in (18) we find that the surface of the sea during
the summer of 1915 was 11-1 cm. higher at Station X 31 in the gulf of St. Lawrence
than at station XIII 38 south of Nova Scotia. And as the Gaspe current carries
645,000 tons of water per second, its production of energy amounts to 955,000 horse-
power, this force being utilized for its proi:)ulsion, and converted into heat by the
internal friction of the water.

By thus directly comparing the ocean currents with rivers, we find it easier to
comprehend the nature of the former, and the processes .which take place therein. In
a river, the slope of the river-bed occasions a continual transformation of potential
energy into motive power. So also with ocean currents. In these, the slope of the sea's
surface and of the isobars will represent a certain quantity of potential energy, which
is gradually transformed into motive power, and thus maintains the movement of the
current. And we have just seen, how the magnitude of this transformation of energy
may be expressed in horse-power.

It is thus easy to follow the transformation of energy in the sea. The heat
derived from the rays of the sun in the Tropics is first converted into potential energy,
which again is then transformed into motive power, setting in motion currents which
transport the warmer water to higher latitudes, where the heat is again given off from
the sea. By periodical oscillations in the movement of the sea-water, the energy repre-
sented is continually being converted from potential force to motive power, and vice
versa. The potential energy, however, after first being transformed into motive power,
is thence again converted by the internal friction of the water into heat. We have thus
the following system of transformation of energy in the sea : —

HEAT ^ POTENTIAL ENERGY "> MoTIVl-: POWER .> HEAT.

This applies to all ocean currents. Thu:? the water in tlie St. Lawrence river, for
instance, is due to the heating of the sea-water by the sun's rays, viz., firstly evapora-
tion, then raining. The mixing of this fresh water with sea-water in the gulf of St.
Lawrence gives rise to the potential energy which propels the Gaspe current. And
finally, the motive power of this latter is transformed, by the internal friction of the

CAXADIAX FlsIlKlilEs EXI'EDITIOX, J<)1.',-JJ 287

water, into heat. In the case of the (jaspe current, the measure of these three trans-
iiorniations of energy will be 955,000 horse-power.

The divergence of the sea's surface from the level of gravitj- is primarily due to
such physical changes in the sea-water as bring about an alteration of its specific
gravity. The topography of the sea's surface is, however, further influenced by the
earth's rotation, which forces the light surface water of the currents to the right; and
also by the wind, which forces the water to store uj). In addition, the surface of the
8(-a is subjected to various periodical perturbations, taking the form of sea waves,
seiches, swells, etc. In all such obliquities of the sea's surface, however, the water will
always be accelerated by the component which falls in the surface of the sea, if the
force of gravity is projected upon the same.

One deformation of the sea's surface should be reckoned in a class apart, viz., that
due to atmospheric pressure. If, for instance, the pressure above a certain area of sea
should fall from, say, 760 to 720 mm., then according to (15) the pressure will be corre-
spondingly reduced, and this, moreover, right down to the bottom of the sea ; i.e., all
isobar surfaces within the area in (luestion, down to the greatest depth, will be lowered
34: em. The result of this will be an inflow of water from all sides to the area in ques-
tion, this taking place rapidly, and with imperceptible velocity, as all levels of the water
contribute. When this process has been completed, the surface of the sea within the
area of lowered atmospheric pressure will have risen 54 cm. above its former level, this
height of the water exactly compensating the deficit in atmospheric pressure, so that
the isobars will then resume their normal course, despite the atmospheric perturbation.
The surface of the sea itself, however, will no longer be an isobar surface, and ceases
therefore, to be an indication of the distribution of pressure in the sea. This it can
only become through a combination of water level and atmospheric pressure.

It is therefore a question, whether it might not be worth while, for dynamic purposes
to carry out this combination. The simplest method of so doing is to correct the water
level to a certain pressure, e.g. 1,000000'CGS, corresponding to 750-08 mm. or 29-531
inches Hg. at 0°. This pressure will always be found near the surface of the sea. Insert-
inging now in (15) Sf=980-6 and i'=0-97264, we obtain the required correction of the
water level for the influence of atmospheric pressui'c: —

0.97204

(p — 1000000)

980-6
or

2=0-0009919 (p — 1000000)
Taking now as unit of pressure 1 millibar = 1,000 C.G.S., then

£=09919 (p — 1000) (19)

In mm. Hg.

2=1-3224 (p — 750-08) (20)

and in inches Hg.

3=33-59 (p — 29-531) (21)

Table 7, a, b, and c, gives the correction z to the water level expressed in cm. for differ-
ent atmospheric pressures according to formula? (19), (20), and (21), resi)ectively.

By applying this correction to the water levels observed, we obtain the water
level which determines the distribution of pressure in the sea and the movement of
the water.

Finally, as regards transformation of energy in the sea, it should be borne in
mind that the integral expression in formula (17) gives the area of the closed curve
in ('lapeyron's diagram. In the case of a current .wherq the water flows in a Carnot
circular process, as for instance the Gulf Stream, the quantity of enei-gy converted
from iieat to motive power will thus be equal to the mass of water in circulation, multi-
plied by the number of solenoids. This calculation gives, for the Gulf Stream,

288 DEPARTMENT OF THE NATAL SERVICE

500,000,000 horse-power, which agrees with the value already known from other methods
of calculation.

Nothing could show more clearly than this the fundamental importance of
the solenoids for the origin and maintenance of the ocean currents.

17. SUMMARY.

Within the area of these investigations, from its boundary on the Gulf Stream
side to the mouth of the St. Lawrence, a number of mostly interesting phenomena
are encountered, which render the waters in question one of the most instructive
fields on the face of the globe for hydrographical and hydrodynamic research.

Let us now glance briefly at some of the most important features. First of all,
there are the physical processes which take place in the boundary surface between the
Labrador current and the Gulf Stream occasioning the disappearance of the former,
with regard to these, the reader is referred to Prof. Emil Witte's clear and simple
treatment of the subject in the Geogr. Anzeiger, October, 1910: — ■

" When, on the boundary of an ocean current, warm water of high salinity
is brought into contact with colder water of less saline character, but having
approximately the same specific gravity, then the resulting mixture will, as
may easily be proved by the Knudsen tables, be of greater density than either
of its component parts. It will consequently sink down, giving rise to the
peculiar phenomenon known as cabbeling.

" Obviously, this tendency in the water will likewise produce horizontal
currents; as the mixed water sinks down, surface water must flow in from
either side to take its place. By way of example, we may take the waters in
the vicinity of the Newfoundland bank, where the Gulf Stream encounters the
cold current flowing down from the Greenland seas. Throughout the wide
extent of the boundary surface between these two, mixed water is constantly
being formed, sinking down, and thus drawing in a continual further supply of
surface water from either side."

It is this perpetual sinking of the water, of course, which renders the oceanic
boundary line here so vertical.

Numerous pelagic organisms of slight mobility doubtless meet their death in this
mixture of the water, and their shells sink to the bottom. With the aid of boring
samples taken from the sea floor, therefore, we should probably be able to arrive at the
geological history of these currents.

The water of the Gulfi Stream is more homogeneous; that of the Labrador current
being more in layers. In the boundary surfaces between the layers of the latter, wave
movements take place. These waves strike against the vertical boundary wall, giving
rise to submarine waves of great amplitude. In order to study these, it will be sufHcienr
to measure the depth of an isotherm or isohaline at the juncture of two layers. This
simple operation should be carried out at the same time as the hydrographical measure-
ments.

Closer in towards land, the surface water of the Labrador current is driven
by the earth's rotation in a shoreward direction, which is one of the causes of the
numerous shipwrecks in the Newfoundland waters. The water pours up into the big
bays on the eastern shore, keeping to their north side. The greater part of the water
thus poured in at the surface makes its way out again as an under current, but there is,
as a rule, also a slight surface current in an outward direction on the southern side of
the bays.

South of Newfoundland, the landward current is often perceptible far out at sea.
"A northerly set of 30 miles in twenty-four hours has frequently been experienced in
tliis neighbourhood, at times at a distance of 50 miles from the coast {vide Sailing

CA^'ADIAX FISHERIES EXPEDITIOX, IDl.'rlo 289

Directions from Belle Isle to Boston). In the bays of the south coast of Newfound-
land, the water flows in up their eastern side, and out along the bottom, with an
outward-going surface current also on the western side.

From the foregoing, it will be plain that the majority of the icebergs drifting with
the Labrador current will collect on its western side, making their way up into the bays
on the east and south coasts of Newfoundland as far as Placentia bay. The suction
towards the boundary between the Labrador current and the Gulf Stream will, however,
draw a number of icebergs thither; they may be encountered far out at sea and to the
southward, even occurring down towards the east and south sides of the Great Bank.
In the intermediate zone, between the two ice lines, the current should be relatively
free from ice.

At cape Ray, the water of the Labrador current pours into the gulf of St. Lawrence
at the rate of some 12 cubic miles per day. Its place of destination is here the con-
sumption area at the mouth of the St. Lawrence river, where this quantity of water is
required for the production of the Gaspe current. We have thus in the gulf of St.
Lawrence a solenoid system drawing this water towards the northwest. At cape Ray,
however, where the velocity of the water becomes considerable, owing to the narrow
passage through which it iiows, the influence of the earth's rotation also makes itself
strongly felt. The current, therefore, on entering the bay, veers off to the right in a
curve, this curve being, however, of wide radius, owing to the pressure exerted by the
solenoids in a northwesterly direction. It consequently passes by the bay of St. George
without entering there, touching the west coast of Newfoundland for the first time at
the bay of Islands, and setting on shore from there as far as point Rich.

On the way it loses a great deal of water which sets off westward out into the gulf
of St. Lawrence, making for its destination, the mouth of the St. Lawrence river. The
last remainder of the current also curves out from point Rich into the gulf, following
the attraction of the solenoids. A slight westward current is still perceptible along the
north coast of the bay, from Esquimaux island to cape "Whittle. Morgan strait being
shallower than the level of the solenoid system which draws the water westward, the
current leaves the coast at cape Whittle, passing out east and south of Anticosti to
reach its destination. In the region north of Anticosti, a slight back vortex seems to
arise, as the current is directed eastward along the range of coast beyond Natashquan
point.

South and west of Anticosti, the earth's rotation forces the current over to the
northward. The effect, however, is insignificant, owing to the great extent of the
current in transverse section, and its consequent slight velocity.

At the mouth of the St. Lawrence river, we encounter the mixing process which
gives rise to the Gaspe current. In all probability, the ebb and flow of the tide are,
for this process, of considerable importance.

In this mixed water of the Gaspe current, the fresh water from the St. Lawrence
constitutes a quantitatively insignificant yet highly important ingredient; it is this
which renders the Gaspe water slightly lighter than the surrounding sea-water, which
again gives rise to the solenoid system that forces the Gaspe water out of the gulf of
St. Lawrence, and draws in the Labrador water. Owing to the earth's rotation,
the Gaspe current keeps to the southern side of the entrance to the St. Lawrence,
rounding cape Gaspe, and filling the southern part of the gvli. Here the Gaspe water
accumulates, forming a kind of cushion, and the Gaspe current itself flows thereafter
on the north side of the same. As a rule, the current flows south of the Magdalen
islands, but wdien the " cushion " is well developed, part of the current may go north
of this group. Within the cushion itself reactionary currents arise, especially in the
vicinity of the primary Gaspe current, and where the cushion is very strongly
developed, such a reactionary current may even extend up as far as cape Gaspe, press-
ing the Gaspe current even here out from land.

290 DEPARTMENT OF THE XATAL HERVICE

Gradually, owing to rainfall, inflow of river water, melting of ice, etc., the water
of the cushion becomes somewhat lighter than that of the Gaspe current, and is thus
better able to resist the southAvard pressure of the current itself.

In Cabot strait, the continuation of the Gaspe current keeps close in to cape
North, C. Breton island, owing to the earth's rotation. With a strong easterly wind,
the whole of this current will be stopped, and all its water stored up in the cushion
in the southern part of the gulf of St. Lawrence. The cushion is thereby increased
both in depth and horizontal extent, and consequently, the solenoids in the gulf of
St. Lawrence, which drive the Gaspe water forward, become stronger in turn. If the
east wind keeps up for any length of time, this solenoid system will at last become
so strong as to drive the Gaspe water past cape North, despite the wind against it.
When the east wind drops, the current will be stronger than normal for a time, as it
will then, in addition to the Gaspe water, also have to carry out the superfluous water
of the cushion.

With a southwesterly wind, on the other hand, the water of the cushion will be
driven out through Cabot strait. The current is thus increased at first, but when the
water in the cushion has sufficiently diminished the current past cape North will once
more become normal, despite the southwesterly wind. When the southwesterly wind
ceases, the current will grow weaker, as a great part of the Gaspe water will then go
to form a new cushion. In a word, the effect of this accumulated mass of water may
be popularly described as similar to that of the air in the bag of a Scottish bagpipe.

The principal portion of the Gaspe water is naturally formed outside the mouth
of the St. Lawrence river, but the current also absorbs a considerable amount of water
from its surroundings throughout its course, by friction against the subjacent layer,
and by diffusion. Consequently, the farther it proceeds, the more it increases in
volume and salinity and the more it grows to resemble the water around it. On the
coast of Nova Scotia, and even more in the gulf of Maine, it differs but slightly from
its surroundings, and a storm will here suffice to mix it up completely with the adja-
cent water. Thus far at least, however, the water of the St. Lawrence river flows
before losing its individuality and becoming finally intermingled with the ocean.

We now come to the most remarkable feature in the hydrography and hydro-
dynamics of the Canadian Atlantic area, viz., the cold intermediate layer. From
plates IV and V it will be seen that this is of very great extent, and that it is largely
restricted to a constant level. It is a result of the melting of ice in the gulf of St.
Lawrence, and partly, also in all probability, in the Arctic ocean. From the section
east of cape Ray, it would seem that this layer forms an important intermediate or
lower portion of the Labrador current. Its movement, together with this latter, is
unmistakable. The cold water presses against the banks and the coast, as a result of
the earth's rotation, which forces it towards the right.

It is thus likely that the greater portion of this water is produced farther to the
north, in the Greenland waters. Its thickness decreasing to the southward, we conse-
quently find, in the cold layer itself, solenoids which force it towards this point of the
compass. On reaching Cabot strait, it is forced by the earth's rotation into the gulf
of St. Lawrence, and fills it to the level where it belongs by virtue of its specific
gravity. From the gulf of St. Lawrence it pours out via cape North along the coast
of Nova Scotia or rounding Banquereau. These outward currents are considerably
stronger in spring than in summer, owing to the melting of the ice in the gulf during
the former season. A peculiar phenomenon may be noted in connection with these.
The screwing movement of the ocean current presses the cold subjacent water out
from the shore, vide plates IV and V, where, owing to friction against the water
above, it probably rotates in an opposite direction to the latter, exactly as two cog-
wheels in contact move opposite ways. In this manner, the cold water mass acquires
its rotmded form, as shown in fig. 60.

CA.v.i/>/ i.v risin:ini:s i:xr/:i)iTioy, i!)i',-i5 29i

The layer of eold water is thinner in the centre of the gulf of St. Lawrence
than at peripheral parts of the same; the layer is thus in cyclonic circulation.

The extent and ])ernianonee of the cold water layer show that no interfhan^^e of

Fig. 60.— Circulation of the water in a transverse section
of a current with cold bottom water.

water can take place between the surface and bottom layers in the gulf of St.
Lawrence. The cold layer forms an elastic but impenetrable membrane between the
surface water and the bottom water. Its level is dependent upon the state of the
Labrador current, and thus probably determined by the seasons ; also accidental causes
may, however, have some effect. With an easterly wind, when great quantities of sur-
face water will be pressed in and corresponding masses of bottom water forced out
through Cabot strait, the level of the cold layer will sink in the gulf, and rise outside
it. With a westerly wind, on the other hand, when the surface water is driven out
and the bottom water sucked in through Cabot strait, then the level of the cold layer
is raised inside the gulf and lowered outside. Enormous slow wave movements also
probably take place within the layer. As its level approximately corresponds with
that of the Banks, its change of level will obviously occasion marked changes of
temperature there. These changes of temperature, moreover, probably affect the
occurrence of fish on the banks, as the fish may be presumed to seek that water they
best like. In seeking to locate the fish, therefore, it will undoubtedly be valuable to
know at what level this eold water is to be found.

The warm bottom layer in the gulf of St. Lawrence is connected with the outer
world only by the long, deep channel of the Cabot strait. Ko production or consump-
tion of this water takes place in the gulf of St. Lawrence, and its movements there
are consequently insignificant. In the deep channel through the Cabot strait, how-
ever, this water may at times exhibit no inconsiderable degree of movement. Measure-
ments of this deep-water current would be of great dynamic importance, possibly
also important in biological respects, since they would show whether the cold layer
were rising or falling, i.e., in what direction the hydrographic condition of the gulf of
St. Lawrence is tending. The deep water of the gulf of St. Lawrence may be considered
as an elastic membrane exhibiting a number of important hydrogi-aphical phenomena,
all of which exert their influence upon it. The current flowing inward and outward
through the deep channel of Cabot strait indicates the measure of this influence, and
thus affords a valuable means of discerning what is taking place in the gulf of St.
Lawrence.

292

DEPARTME'NT OF THE NAYAL SERVICE

Table la. — Specific volume Vi and stability S of the water in the Gulf of
St. Lawrence during the spring 1915.
C. G. S. "PRINCESS".

Station, time,

s

Station, time,

s

j::

Vl.

S.

^

Vl.

S.

position, depth.

o.

©

Q

position, depth.

P

Stat. 1

May 11

0

663

0

Sect. I, 7.

June 10

0

934

89

N. 47° 30' 00"

10

663

N. 47° 50'

10

845

W. 63° 23' 00"

20

616

47

W. 63° 37'

25

592

169

69 m.

30
40
50

600
554
548

16

46

6

76 m.

50
75

562
514

12
19

4

65

542

Sect. I, 8.

June 10

0

802

62

Stat. 2

May 11

0

671

0

X. 48° 11'
W. 63° 04'

10

740

147

N. 47° 27' 00"

10

671

20

593

W. 62° 10' 30"

20

651

20

92 m.

40

553

20

45 m.

30
40

623
555

28
68

60
90

506
469

24
12

Stat. 3

June 9

0

930

134

N. 46° 02'

10

796

Sect. I, 9.

June 11

0

642

W. 63° 25'

19

37

20

777

N. 48° 27'

25

.550

25 m.

22

771

30

W. 62° 37'
160—300 m.

75

471

16
17

100

428

Stat. 4

June 9

0

899

18

150

382

9

N. 46° 28'
W. 64° 21'

5

890

28-

10

876

Sect. I, 10.

June 11

0

631

21 m.

32

35

20

844

N. 48° 53' .
W. 61° 50'

25

538

14

50

503

Sect. I, 5.

JunclO

0

935

58

150—2.50 m.

75

452

20

N. 47° 13'

10

877

10

W. 64° 35'

20

742

135

100

427

6

31 m.

30

635

107

1.50
200

395
370

5

June 10

0

909

Sect. I, 6.

221

Sect. I, 11.

June 11

0

617

N.47°,30'

10

688

6

W. 64° 08'

20

630

58

N. 49° 02'
W. 61° 32'

10

611

39

61 ra.

30
40
60

558
557
525

72

1
16

51 m.

20
25
40
50

.572
513
508
489

39

3

19

CANADIAN FISHERIES EXPEDITION, IDL'rl'j

293

Table la. — Specific volume ri. and stability ^S of the water in the Gulf of
St. Lawrence during the spring 1915 — Continued.

G. C. S. " PRINCESS "—Continued.

Station, time.

~

Station, time.

-

-2

V\.

S.

■~

t'l.

S.

position, depth.

a

Q

position, depth.

a.

o

Q

Sect. I, 12. .June 11

0

630

65

Sect. II, 17.

June 12

0

564

8

N. 49° 27'

10

565

N. 49° 22'

25

544

W. 61° 20'

25

526

26

W. .58° .56'

50

505

16

140 m.

50
75

495
448

12
19

8

130 m.

75
100

456
440

20

6

10

100
125

427
421

2

125

415

!

Sect. II, 18.

June 12

0

590

Sect. I. 13. .June 11

0

819

103

N. 49° 16'

30

513

26

N. 49° 4.5'

25

561

W. .58° 37'

32

W. 61° 15'

50

493

27

64 m.

40

481

8

ca. 200 m.

75

449

18

50

473

3

100

441

11

Sect. III. 19.

June 13

0

£63

10

125

414

2

N. 48° 20'
W. .59° 13'

10

553

1

150

408

5

82 m.

20

552

41

200

384

30

511

11

Sect. I, II, 14. .June 11

0

996

50

490

311

31

N. 50° 07'

10

685

60

458

W. 61° 09'

20

535

150

80

445

7

40 m.

26

35

496

Sect. III. 20.

N. 48° 06'

.June 13

25
50

556

538

7

Sect. II, 15. June 12

0

769

7

W. 59° 40'

22

N. 49° 45'

10

762

75

482

W. 60° 08'

20

636

126

2.50— 400 m.

100

451

12

85 m.

40
60
80

483
455
422

77
14
17

125
150
200

427
409
371

10

7
8

Sect. II, 16. June 12

0

580

12

Sect. Ill, 21.

June 13

0

543

0

N. 49°33'

25

550

N. AT .52'

25

542

W. 59°31'

50

497

21

W. 60° 04'

50

499

17

260 m.

75
100
150
200
250

440
420
394
392
364

23
8
5
0
6

ca. .500 m.

75
100
200
300
400

466
442
355
341
314

13

10

9

1
3

294

DEFARTME'NT OF THE NAYAL SERVICE

Table 1«. — Specific volume ih and stability *S of the water in the Gulf of
St. Lawrence during the spring 1915 — Continued.

C. G. S. "PRINCFSS"— rcwr/Md«/.

Station, time,

s

Station,

time.

s

X.

ri.

S.

4=

Vl.

S.

position, depth.

p

position.

depth.

Q

Sect. Ill, 24.

June 15

0

607

Sect. Ill, 22. June 13

10

565

15

N. 47° 12'

10

665

2

N. 47° .3.3'

20

550

W. 61° 20'

27

W. 60° 39'

30

501

49

40 m

25

624

£6

55 m.

40

500

1

35

568

5

Sect. Ill, 25.

June 15

0

746

50

495

N. 46° 45'
W. 61° 27'

10

739

- 7
145

20

594

63 m

47

30

547

Sect. Ill, 23. June 13

20

555

25

40

541

6

N. 47°37'

40

505

4

W. 60°31'

45

481

48

60

533

ca. 100 m.

7

Sect. Ill, 26.

June 15

0

782

55

474

28

N. 46° 20'

10

771

17

60

460

7

W. 62° 04'

20

712

53

80

446

16

40 m

25

683

58

100

414

35

593

90

STEAM DRIFTER "33".

Sect. IV, 21. June 25

0

S05

163

Sect. IV, 23. June 25

0

823

27

N. 48° 51'

10

642

N. 49° 03'

10

7£6

W. 64° 10'

62

W. 63° 58'

188

24

555

20

608

27 m.

355 m.

30
50

557
497

51
3

Sect. IV, 22. June 25

0

826

95

75

452

18

N. 48° 54'

10

731

10

W. 64° 07'

20

586

145

100

428

8

195 m.

30
50

539

492

47
24
11

150
250
350

388
351
328

7
2

75

464

20

100

415

14

Sect. IV, 24. June 26

0

641

125

388

32

0

N.49°23'

10

609

150

375

2

W. 63° 38'

24

587

16

190

368

45 m.

42

469

66

CAXAD/W I'lS III: HIES hWI'KIHTJOW 1UI',-i:

295

Table \a. — Specific volume Vx and stability *S of the water in the Gulf of
St. Lawrence during the spring 1915 — Concluded.

STEAM DRIFTER " Z-i"— Concluded.

Station, time,

s

t'l.

.S'.

Station, time.

s

i'l.

,S'.

po.'^ition, depth.

c

po.sition, depth.

Q.

Q

Sect. IV, 25. .June 20

0

744

4

Sect. IV, 26. June 26

0

825

42

N. 49M8' 30"

10

740

X. 49° 11' 30"

10

783

W. 63° 42' 00"

3S

W. 63° 50' 00"

101

20

702

20

682

271 m.

151

389 rn.

149

30

551

26

30

533

36'

r,o

499

18

50

462

9

7.5

455

15

75

440

7

U)0

418

5

100

422

6

150

393

5

150

394

7

269

335

200
250
380

358
347
321

2
2

296

DEPARTMENT OF THE NAYAL SERVICE

Table 16. — Specific volume Vi and stability S of the water at the Nova Scotian
and Newfoundland banks during the spring 1915.

C. G. S. "ACADIA"

Station, time,
position, depth.

a

Q

Vl,

S.

Station, time,
po.sition, depth.

E

Q.
P

Vl.

S

Sect. V, 1. May 29

N. 44° .3.5' 00"
W. 6.3° 32' 00"
25 m.

10
20

611
554

57

Sect. V, 5. May 30

N. 4.3° 56' 00"
W. 61° .32' 00"

73 m.

0
10
25
50
70

505
498
408
460
437

7

11

8

Sect. V, 2. May 29

N. 44° 29' 00"
W. 63° 22' 00"

60 m.

0
10
20
30
40
55

603
603
599
.571
542
518

0

4
28
29
16

12

Sect. V, 6. May .30

N. 43° 47' 00"
W. 60° 52' 00"

45 m.

0
10
20
30
40

519
519
519
517

508

0
0
2
9

Sect. V, 3. May 29

N. 44° 22' 30"
W. 62° 55' 00"

146 m.

0
10
20
30
40
50
60
75
90
110

606
604
.592
529
498
486
483
472
454
445

2

12
63
31
12

3

7
12

5

Sect. V, 7. May 30

N. 43° 35' 30"
W. 60° 13' 30"

109m.

0
25
50
75
100

528
514
429
429
.387

6
34

0
17

Sect. V, 8. May 30

N. 4.3° 50' .30"
W. 60° 04' 30"

51 m.

0
10
20
30
40
50

539

538
524
510
509
501

1

14
14

Sect. V, 4. May 29

N. 44° 07' 14"
W. 62° 11' 36"

0

10

25

40

50

60

100

120

160

564
564
555
524
503
474
425
406
379

0
6
21
21
29
12
10
7

1
80

173 m.

Sect. V, 9. May 30

N. 43° 44' 00"
W. 59° 24' 00"

106 m.

25
40
50
75
100

501
437
421
421
401

43

16

0

8

CANADI.W FISHERIES KXrEDlTIOX, I'Jl'f-lo

297

Table Ih. — Specific volume i\ and stability F> of tlio water at the Xova Scotian and
Xevvfoundland hanks during- the spring 1915 — Continued.

C. G. S. " ACADIA " — Continued.

Station, time,

-

Station, time.

s

■~

ri.

S.

^

ri.

S.

position, depth.

a

position, depth.

Q

Sect. V, 10. May 30

0

488

4

Sect. V, 13. May 31

0

508

20

X. 4.3° 41' .30"

25

476

X. 43° 27' 35"

25

459

"W. 59° 02' 00"

10

W. 27° 18' 25'

23

50

451

50

402

740 111.

10

over .500 ni.

6

60

441

6

75

387

8

75

432

26

100

366

4

90

393

5

150

347

2

100

.388

6

200

337

150
300

360
.332

2

1

400

318

Sect. Y. 14. May 31

0

451

3

X. 43° 20' 00"
W. 56 28' 30"

25

443

5

Sect. Y. 11. May .30

25

471

6

over 500 m.

50

430

0

X. 43° 38' 00"

50

455

75

430

W. 58° 35' 00"

23

61

75

398

85

369

over 500 m.

8

2

100

378

5

100

366

5

125

366

7

125

353

2

150

348

1

150

348

1

300

338

1

300

327

1

400

328

400

321

Sect. V, 12. May 31

0

479

2

N. 4.3° 31' 00"

10

477

Sect. Y. 15. May 31

0

472

VV. 57° 46' 00"

31

1

25

431

X. 43 07 '.M"

25

470

over 500 m.

2

W. 55 17' 55"

15

50

427

4

over 500 m.

50

433

0

75

418

4

75

432

18

100

408

3

100

388

5

125

400

9

150

362

2

150

377

5

300

337

1

175

364

2

400

326

300

345

1

400

333

6551—23

298

DEPARTMENT OF THE NAVAL SERVICE

Table 1&.— Specijfic volume V\ and stability S of the water at the Nova Scotian
and Newfoundland banks during the spring 1915 — Continued.

C. G. S. " ACADIA. "—Contimied.

Station, time,
position, depth.

s

Q

I'l.

S.

Station, time,
position, depth.

s

c.

03

Q

Vl.

S.

Sect. V, VI, 16. June 1

N. 42° 53' 00"
W. 54° 09' 00"

over 500 m.

0
25
75
100
200
300
400

411
409
399
391
375
362
.346

1
2
3
2
1
2

Sect. VI, 20. June 2

N. 44° 59' 00"
W. 54° 17' 00"

91m.

0
25
50
75

463
460
445
416

1
6

12

Sect. VI, 21. June 2

N. 45° 28' 00"
W. 54° 28' 00"

116 m.

0

35

50

65

100

453
433
432
409
394

6

1

15
4

Sect. VI, 17. June 1

N. 4.3° 1.3' 50"
W. 54° 12' 50"

over 500 m.

25
50
100
150
300
400

405
397
395
379
364
352

3
0
3

1

1

Sect. VI, VII, 22. June 2

N. 45° 50 '30"
W. 54° 20 '00"

73 m.

0
20
40
50
60

460
455
445
425
411

3

8

Sect. VI, 17a. June 1

N. 43° 56' 00"
W. 54° 16' 00"

over 500 m.

0

75
100

436
383
380

7
1

20
14

Sect. Vll, 23. June 2

N. 45° 39' 00"
W. 55° 03' 00"

100 m.

0
25
50
60
75

459
456
435
421
421

Sect. VI, 18. June 1

N.44° 11' 30"
W. 54° 13' 00"

over 500 m.

0

25
50
75
100
150
300
400

460
455
446
396
383
362
327
317

2

4

20

5

4
2

1

1
8
14
0

Sect. VII, 24. June 2

N. 45° 16' 30"
W. 59° 29' 50"

120 m.

0
50
75
100

465
436
416
415

6

g

Sect. VI, 19. June 1

N. 44° 35' 00"
W. 54° 15' 00"

0

25

50

75

100

150

300

400

462
462
454
377
376
366
340
339

0
3
31
0
2
2
0

0

over 500 m.

Sect. VII, 25. June 2

N. 44° 56' GO"
W. 5.5° 54' 00"

124 m.

0

25

50

100

120

457
445
418
404
391

5
11
3

7

CANADIAN FISHERIES EXPEDITION, 1914-15

299

Table 16. — Specific volume ^'i and stability (S of the water at the Nova Scotian
and Newfoundland banks during the spring 1915 — Continued.

C. G. S. " ACADIA " — Continued.

Station, time,
position, depth.

O.

Q

rg.

S.

Station, time,
position, depth.

a
o

Q

Vl.

S.

Sect. VII, 26. June 2

N. 44° 31 '00"
W. 56° 25' 30"

over 500 m .

0
25
50
100
125
150
300
400

507
473
457
391
363
346
322
313

14

6

13

11

7

16

1

Sect. VIII, 30. June 3

N. 44° 40' 50"

W. .58° 42' 00"

127 m.

0
25
50
75
100
125

563

542
490
487
472
454

8

21

1

6

7

Sect. VIII, 31. June 3

N. 45° 13' 00"
W. 58° 59' 00"

85 m.

0
25
50
75

584
563
493
481

8

Sect. VII, VIII, 27. June 3

N. 44° 06' 00'
W. 56° 54' 00"

over 500 m.

25

50

75

100

150
300
400

464

438

406

386\
376/

369
327
315

10
13
10

2
3

1

28
5

Sect. VIII, 32. June 3

N. 45° 48' 30"
W. 59° 13' 00"

155 m.

0

25

50

100

150

572
532
517
455
419

16

6

12

7

Sect. VIII, IX, 33. June 4

N. 46° 16' .30"
W. 59° 33' 00"

ca. 73 m.

0
15
25
40
50
75

630
624
571
532
516
470

Sect. VIII, 28. Juno 3

N. 44° 12' 00"
W. 57° 24' 00"

over 500 m.

0

25

50

75

100

150

300

400

542
513
495
450
423
373
340
314

12

7

18

11

10

2

3

4
53
26
16
18

Sect. IX, 34. June 4

N. 46° 40' 00'
W. 59° 00' 00"

ca. 350 m.

0

25

50

100

200

300

522
498
469
453
394
339

10

Sect. VIII, 29. June 3

N. 44° 21' 36"
W. 58° 08' 00"

58 m.

0
40
55

550
522
475

7
32

12
3
6
6

6551—23*

300

DEPARTMENT OF THE NAVAL SERVICE

Table 16. — Specific volume Vi and stkbility S of the water at the Nova Scotian
and Newfoundland banks during the spring 1915 — Concluded.

C. G. S. " ACADIA " — ConcludecW.

Station, time,

s

Station, time,

e

JIl

Vl.

S.

j2

Vl.

S.

position, depth.

o

Q

position, depth.

a.

Q

Sect. IX, 35. June 4

0

514

5

Sect. IX, 36. June 4

0

521

12

N. 47° 04' 00"

15

507

N. 47° 26' 00"

25

492

W. 58° 26' 00"

10

W. 57° 57' 00"

14

30

492

50

458

ca. 450 m.

13

230 m.

5

50

462

12

75

445

5

75

431

6

150

406

7

100

417

200

369

150

380

3

300

329

1

400

321

CANADIAN FISHERIES EXPEDITION, 1911,-15

301

Table Ic. — Specific volume V\ and .stability <S of the water in the Gulf of
St. Lawrence during the summer 1915.

C. G. S. " PRINCESS

-Continued.

Station, time,
position, depth.

o.

o

Vl.

S.

Station, time,
position, depth.

c

D.

Q

Vl.

S.

Stat. 27. Aug. 3

X. 46° 02'

W. 63° 24'

23 m.

0
10
20

1019
997
744

22
253

Sect. X, 32. Aug. 4

N. 48° 00'
W. 63° 25'

87 m.

0
10
25
50
75
85

982
774
607
514
489
482

208

111

37

10

Stat. 28. Aug. 3

0
10
20

1082
1044
1032

38
12

7

X.46°31'
W. 64° 20'

23 m.

Sect. X, 33. Aug. 4

N. 48° 17'
W. 62° 54'

78 m.

0
10
25
50
75

954
752

567
487
438

202
123
32
20

Sect. X, 29. Aug. 4

0
10
15
20
25

1122
1032

885
815
785

90
294
140

60

N. 47° 13'
W. 64° 36'

32 m.

Sect. X, 34. Aug. 4

N. 48° 27'
W. 62° 37'

405 m.

0

10

25

50

75

100

150

200

300

350

828
706
626
488
454
424
383
363
329
321

122

53

55

13

12

8

4

3

2

Sect. X, 30. Aug. 4

X.47°31'
W. 64° 09'

66 m.

0
10
25
40
50
60

1013
1007
850
753
659
523

6

105

65

94

136

Sect. X, 35. Aug. 5

N.48°41'
W. 62° 15'

oa. 400 m.

0

10

25

50

75

100

150

200

300

350

775
756
568
471
449
428
396
367
331
326

19
125
39
9
8
6
6
4
1

Sect. X, 31. Aug. 4

N.47°47'
W. 6.3° 45'

65 m.

0
10
25
40
50
60

1068
1000
784
667
535
497

68
144

78
132

38

302

DEPARTMENT OF THE NAYAL SERVICE

Table Ic. — Specific volume Vi and stability S of the water in the Gulf of
St. Lawrence during the summer 1915 — Continued.

C. G. S. " PRINCESS " — Continved.

Station, time,
position, depth.

s

Hi

Q

n.

S.

Station, time,
position, depth.

6

a

Q

I'l.

S.

Sect. X, 36. Aug. 5

N. 48° 58'
W. 61° 48'

53 m.

0
10
25
35
50

827
826
667
523
497

1
106
144

17

Sect. X, XI, 40. Aug. 5

N. .50° 05'
W. 61° 16'

68 m.

0
10
25
40
50
65

848
615
522
486
469
468

233

62

24

17

0

0
10
25
50
70

785
774
549
474
443

11

150

30

16

Sect. X, 37. Aug. 5

N. 49° 06'
W. 6r21'

75 m.

Sect. XI, 41. Aug. 6

N. 49° 54'
W. 60° 37'

189 m.

0

10

25

50

75

100

150

180

776
775
597
504
455
431
411
385

1

119

37

20

10

g

Sect. X, 38. Aug. 5

N. 49° 28'
W. 61° 22'

180 m.

0
10
25
50
75
100
150
175

816
797
523
462
. 434
417
392
392

19

183

24

11

7

5

0

9

Sect. XI, 42. Aug. 6

N. 49° 45'
W. 60° 07'

90 m.

0
10
25
50
75
85

749
748
615
496
437
436

1
89
48
24

1

Sect. XI, 43. Aug. 6

N. 49° 33'
W. 59° 28'

265 m.

0

10

25

50

75

100

150

200

250

749
748
601
496
445
427
402
374
346

Sect. X, 39. Aug. 5

N. 49° 45'
W. 61° 19'

284 m.

0

10

25

50

75

100

150

200

275

801
790
527
462
437
417
400
385
338

11

175

26

10

8

3

3

6

1

98

42

20

20

5

5

6

CANADIAN FISHERIES EXPEDITION, 1914-15

303

Table Ic. — Specific volume vi and stability S of the water in the Gulf of
St. Lawrence during the summer 1915 — Cunlinued.

C. G. S. " PRINCESS "—Cmicluded.

Station, time,

s

Station, time.

c

4^

Vl.

S.

Vl.

S.

position, depth.

1

position, depth.

a

Q

Sect. XI, 44. Aug. 6

0

753

2

Sect. XII, 47.

Aug. 12

0

833

55

N. 49° 24'

10

751

X.47°25' •

25

696

W. 58° 55'

25

589

108

W. 60° 10'

50

552

58

157 m.

.50
75
100
150

485
451
430
401

42
14
8
6

410 m.

75
100
150
200
300

481
451
402
378
342

28
12
10
5
4

2

Sect. XII, 45. Aug. 12

0

660

14

400

321

N. 4r 5.3'

25

624

Sect. XII. 48.

Aug. 12

0

878

W. 59° 38'

44

99

50

513

N. 47° 08'

25

631

380 m.

75
100
150
200
300

467
454
436
398
313

18
5
4
8
9
0

W. 60° 31'
175 m.

50

75

100

125

170

498
446
427
383
364

53
21

8
18

4

375

310

Sect. XII, 49.

Aug. 12

0

990

30

N. 46° 40'

10

960

W. 61° 14'

206

Sect. XII, 46. Aug. 12

0

690

36

75 m.

25

651

116

N. 47° 41'

25

600

35

535

W. 59° 52'

50

477

49

50

523

8

ca. 455 111.

75

454

9
6

60

504

19
37

100
150

438
399

8

70

467

Sect. XII, 50.

Aug. 12

' 0

959

7

2

200

365

3

N. 46° 18'
W. 61° .59'

10

957

97

300

332

1

42 m.

25

811

150

400

320

40

586

304

DEPARTMENT OF THE XATAL SERVICE

Table Ic. — Specific volume Vi and stability *S of the water in the Gulf of
St. Lawrence during the summer 1915 — Concluded.

STEAM DRIFTER "33".

Station, time.

£

Station, time.

s

JS

Vl.

S.

JS

V\.

Si

position, depth.

o

Q

position, depth.

a.

o
Q

Stat. 54. Aug. 7

0

1393

679

Stat. 59. Aug. 10

0

790

88

South Arm,

10

714

Inside South Head,

10

702

Bay of Island,

105

Bay of Island.

101

Newfoundland.

25

557

15

275 m.

25

551

25

110 m.

50

519

18

50

488

6

75

473

3

75

472

5

100

465

100

460

3

150

446

0

Stat. 58. Aug. 10

0

784

72

200

444

0

Off South Head,

10

712

270

442

Bay of Island.

25

564

99

50 m.

45

501

32

CAXADIAX FISHERIES EXPEDITIOX, 191^-15

305

Table Id. — Specific volume vu and stability *S of the water on the Nova Scotian
and Newfoundland banks during the summer 1915.

C. G. S. " ACADIA.

Station, time,

E

Station, time.

£

Vl.

S.

Ji

Vl.

S.

position, depth.

a

Q

position, depth.

D.

Q

Sect. XIII, .37. July 21

0

653

37

Sect. XIII, 41. July 22

0

594

17

X. 4.3° .33 '00'

20

579

N.42° 17' 00"

25

551

W. 65° 12' 50"

27

W. 64° 30' 30"

52

40

525

50

421

62 m.

8

420 m.

4

60

509

75
100

410
392

7
3

150

376

2

Sect. XIII, 38. July 21

0

709

32

200

366

2

N. 43° 14' OO'

25

630

300

345

W. 6.5° 02' 00'

29

1

50

558

400

326

170 m.

75

501

23

19

100

453

5

Sect. XIII, 42. July 22

0

599

18

125

440

5

X. 41° .58' 00"
W. 64° 20' 00"

25

554

47

150

427

over 1,000 m.

50
75

437
402

14
6

100

388

3

Sect. XIII, 39. July 21

0

693

20

150

371

3

N. 42° 55' 00"

25

642

200

359

W. 64° 51' 00'

18

1

40

606

300

345

95 m.

84

2

50

522

16

400

328

75

483

1

90

481

Sect. XIII, 43. July 22

0

609

18

X. 41° 38' 30"

25

563

W. 64° 10' 00"

21

50

510

over 1,000 m.

32

Sect. XIII, 40. July 22

0

738

83

75

430

2

X. 42° 36' 00"

25

531

100

424

W. 64° 41 '00"

26

6

50

467

150

396

134 m.

17

1

75

425

6

200

391

3

100

410

8

300

362

2

125

389

400

340

306

DEPARTMENT OF THE NAVAL SERVICE

Table Id. — Specific volume Vi, and stability S of the water on the Nova Scotian
and Newfoundland banks during the summer 1915 — Continued.

C. G. S. " ACADIA" — Continued.

Station, time,

s

Station, time.

g

Vl.

S.

—

Vl.

S.

position, depth.

position,

depth.

a

Qj

Q

Sect. XIII, XIV, 44. July 22

0

646

13

Scot. XIV, 48.

July 23

0

724

37

N. 41° 19' 00"

25

613

N. 4.3° 53' 30"

25

632

W. 63° 59' 00"

50

514

40

W. 62° 58' 30"

50

468

66

Over 1,000 m.

75
100
150
200
300
400

445
402
380
369
348
325

28
17
4
2
2
2

264 m.

75
100
125
150
200
250

439
407
378
369
356
349

12
13

12
4
3

1

0

588

Sect. XIV, 45. July 22

4

Sect. XIV, XV, 49.

Julv 23

0

750

N. 42° 02' 00"

25

577

61

W. 63° 43' 00"

50

490

35

N. 44° 30' 30"
W. 62° 43' 00"

25

598

55

Over 1,000 m.

75
100
150
200
300
400

434
410
382
369
328
316

22
10
6
3
4
1

135 m.

40

50

75

100

125

516
504
482
472
*454

12
9
4

7

Sect. XV, .50.

Julv 23

0

714

Sect. XIV, 46. July 23

0

695

38

N. 44° 12' 15"

25

587

51

N. 42° 31' 00"

25

600

W. 62° 35' 00"

48

W. 63° 31' 30"

50

442

64

155 m.

50

467

12

Over 1,000 m.

75
100
150
200
300

418
409
375
371
333

10

4
7

1
4

75
100
125
150

436
408
393
386

11
6
3

Sect. XV, 51.

Julv 23

0

688

0

35

400

332

N. 4.3° 52' 00"
W. 62° 18' 00"

25

601

87

Sect. XIV, 47. July 23

0

610

11

1.33 m.

40

471

16

N. 43° 15' 00'

25

582

50

455

W. 63° 13' 30"

50

498

34

75

417

15

144 ra.

75

413

34

7

100

395

9

2

100

396

6

125

389

125

380

CANADIAN FISHERIES EXPEDITION, lOUflS

307

Table Id. — Specific volume V], and stability S of the water on the Xova Scotian
and Newfoundland banks during the summer 1915 — Continued.

C. G. S. " ACADIA" — Continued.

Station, time.

i

Station, time.

i

Vl.

S.

■2

ri.

S.

position, depth.

position, depth.

a

Q

Sect. XV, .52. .July 2-1

0

645

30

Sect. XV, XVI, 56. July 24

0

768

94

N. 4.3° 31' 00"

25

569

X.42° 16' 00"

25

533

W. 62° 01' 00"

58

W. 61° or 00"

40

40

482

50

434

9.5 m.

25

Over 1,000 m.

7

50

457

20

100

398

5

60

437

5

150

372

0

75

430

13

200

371

3

90

404

300

344

1

400

339

Sect. XV, 53. July 24

0

618

35

N. 43° 14' 30'

25

530

W. 61° 48' 00"

40

452

52

Sect. XVI, .57. July 24

0

679

50

99 m.

7

X. 42° .57' ?0"

25

553

50

445

7

W. 60° 56' 00"

50

452

40

75

428

5

Over 1,000 m.

75

405

19

95

419

100

386

8
6
3
2

1

Sect. XV, 54. July 24

0

670

150

356

N. 42° 57' 30"

25

£63

43

200

342

VV. 61° 34' 00"

50

422

56

300

322

Over 1,000 m.

75
100

387
385

14

1

400

311

150

357

6
1
4

Sect. XVI, .58. July 24

0

658

43

200

353

N. 4.3° 23' 00"
W. 60° 53' 00'

25

550

42

300

317

50

445

1

187 m.

3

400

309

75

437

18

100
125

393
378

Sect. XV. 55. July 24

0

712

70

6

N. 42°41' 15"
W. 61° 21' 00"

25

536

40

150

367

4
3

50

437

359

Over 1,000 m.

17

lio

75
100
150

395
393
361

1
6
1
1
3

Sect. XVJ, 59. July 25
X. 43° 48' 30"

0
15

642
635

5

200

355

W. 60° .50' 00'

30

565

47

300

345

45 m.

45

510

37

400

320

i

308

DEPARTMENT OF THE XAVAL SERVICE

Table Id. — Specific volume Vi, and stability S of the water on the Nova Scotian
and Newfoundland banks during the summer 1915 — Continued.

C. G. S. " ACADIA" — Continued.

Station, time,

s

Station, time,

E

J3

Vl.

S.

J3

Vl.

S.

position, depth.

a.
Q

position, depth.

a

0)

Q

Sect. XVI, 60.

July 25

0

668

38

Sect. XVII, 67. July 25

0

699

1

N. 44° 13' 30"

25

573

N. 44° 49' 00"

10

698

W. 61° 14' 00"

50

469

42

W. 59° 40' 00"

25

611

58

98 m.

75

427

17
6

205 m.

50

486

50
10

95

414

75
100

460
455

2

Sect. XVI, 62.

July 25

0

691

22

150

438

3

N. 44° 34' 30"

25

637

2

VV. 60° 47' 00"

40

544

62

200

429

62 ni.

32

50

512

15

Sect. XVII, 68. July 26

0

673

60

497

N. 44° 32' 00"
W. 59° 04' 00"

10

655

18

91

Sect. XVI, 63.

July 25

0

693

44

54 m.

25

518

13

N. 44° 43' .30"

25

584

40

498

W. 60° 46' 00"

50

496

35

50

485

13

55 m.

Sect. XVI, 64.

July 25

0

754

40

Sect. XVII, 69. July 26

0

693

1

N. 45° 04' 00"

25

653

N. 44° 19' 15"

10

692

W. 60° 46' 00"

50

551

41

W. 58° 36' 00"

25

641 \

61

120 m.

75

476

30
6

64 m.

40

558/
493\

74

110

454

50

485/
484

5

Sect. XVI, XVII, 65.

July 25

0

793

46

N. 45° 17' 00"

10

747

W. 60° 42' 30"

25

618

86

Sect. XVII, 70. July 26

0

659

52

105 m.

50
75
100

509
497
480

44
5

7

N. 44° 05' 00"
W. 58° 05' 00"

Over 1,000 m.

25

50

75

100

528
441
401
375

35
16
10

5

Sect. XVII, 66.

July 25

0

732

4

150

352

3

N. 45° 08' 00"

10

728

200

338

W. 60° 23' 00"

25

726

1

.300

326

1

64 m.

40
50
60

608
528
491

79
80
37

400

315

1

CAXADIAX FISHERIES EXPEDITION, WUlo

309

Table Id. — Specific volumo vi, and stability S of the water on the Nova Scotian
and Newfoundhind banks during the summer 1915 — Continued.

C. G. S. "ACADIA" — Continued.

Station, time.

jj

Station, time.

s

js

I'l.

S.

j:

V\.

S.

position, depth.

a.

o

a

position, depth.

a.

o
Q

Sect. XVII, 71. .July 26

0

605

Sect. XVII.

46

XVIII, 75. July 26

0

649

X. 43° 57' 00"

25

545

10

W. .57° 46' 30"

39

N. 43° 30' 00"

10

639

50

448

W. 56° 43' 00'

61

Over 1,000 in.

21

25

548

75

396

9

Over 1,000 m.

50

506

17

100

373

75

413

37

8

100

394

Sect. XVII, 72. July 26

0

708

75

150

381

3

N. 43° 51' 30"

25

521

3

W. 57° 33' 00"

50

430

36

200

367

2

Over 1,000 m.

75
100
150

401
381
362

12
8
4

300
400

344
329

1

2

200

353

2

Sect. XVIII, 76. July 27

0

775

300

333

1

N. 43° 55' 30"

25

626

60

400

321

W. 56° 13' 00"

50

451

70

Over 1,000 m.

75

417

14

11

100

389

Sect. XVII, 73. .July 26

0

703

66

150

362

5

N. 43° 46' 00"

25

539

4

W. 57° 21' 00"

50

424

46

200

341

2

Over 1,000 m.

75
100

394
379

12
6

300
400

322
314

1

Sect. XVIII, 77. July 27

0

747

80

Sect. XVII, 74. July 26

0

697

72

N. 44°21' 15"
W. 55° 42' 30"

10

667

96

N. 43° 41' 00"

25

517

25

523

W. 57° 08' 00"

35

Over 1,000 m.

36

50

429

50

433

Over 1,000 m.

10

10

75

403

4

75

407

6

100

392

3

100

391

6

150

375

1

150

362

4

200

369

2

200

344

2

300

346

2

300

326

1

400

329

400

317

310

DEPARTMENT OF THE NAYAL SERVICE

Table Id. — Specific volume Vy, and stability S of the water on the Nova Scotian
and Newfoundland banks during the summer 1915 — Continued.

C. G. S. " ACADIA '

-Continued.

Station, time,

s

Station, time,

S

■5

Vu

S.

JS

Vl.

S.

position, depth.

o.

Q

position, depth.

o.

o
Q

Sect. XVIII, 78. July 27

Sect. XIX, 82.

July 27

0

616

0

N. 44° 33' 00"

0

667

N. 46° 11' 00"

10

616

W. 55° 29' 00"

50

418

50

W. 55° 54' 00"

25

551

43

Over 1,000 m.

75
100

395
370

9
10

58 m.

40
50

509
445

28
64

Sect. XVIII, XIX, 79. July 27

0

617

43

Sect. XIX, XX, 83.

July 28

0

625

18

N. 44° 47' 00"

10

574

N. 46° 32' 00"

25

580

W. 55° 13' 00"

25

525

33

W. 56° 04' 00"

50

457

49

410 m.

50
75
100
150

456
407
381
361

28
20
10

4
2

172 m.

75
100
125
150

437
428
420
413

8
4
3
3
2

200

350

2

170

409

300
400

330
318

1

Sect. XX, 84.

July 28

0

610

3

N. 46° 17' 00"
W. 56° 37' 00"

10

607

38

Sect. XIX, 80. July 27

0

637

21

60 m.

25

550

41

N. 45° 17' 00"

10

616

40

489

W. 55° 27' 00"

25

561

37

50

438

51

155 m.

40

478

55

33

50

445

13

Sect. XX, 85.

July 28

0

724

66

75

412

2

N. 46° 02' 45"
W. 57° 09' 00"

20

592

53

100

407

0

492 m.

40

487

35

125

406

0

50

452

14

150

406

75

418

9

100

395

5

Sec*. XIX, 81. July 27

0

611

14

150

368

4

N. 45° 48' 30"

10

597

200

347

W. 55° 43' 00"

25

508

59

300

324

2

56 m.

29

1

40

464

4

400

311

54

459

CANADIAN FISHERIES EXPEDITION, 191^-15

311

Table Id. — Specific volume Vu and stability *S' of the water on the Nova Scotian
and Newfoundland banks during the summer 1915 — Concluded.

C. G. S. " ACADIA" — Concluded.

Station, time,

p

Station, time.

E

-5

Vl.

S.

"^

Vl.

S.

position, depth.

a.
c

position, depth.

o.

Q

Sect. XX, 86. July 28

0

726

84

Sect. XX, 88. July 28

0

792

88

N. 45° 47' 00"

25

515

N. 45° 26' 00"

25

573

W. 57" 34' 00"

30

W. 58° 34' 30'

33

50

439

40

524

455 m.

15

130 m.

12

75

402

1

50

512

12

100

399

7

75

483

11

150

362

2

100

456

16

200

352

3

125

417

300

326

2

400

311

Sect. XX, 89. July 28

N. 45° 16' 00'
W. 59° 04' 00"

0
25

775
665

44
65

50

503

130 m.

8

Sect. XX, 87. July 28

0

726

85

75

484

0

N. 45° 38' 30'

15

598

100

484

W. 57° 59' 30"

86

4

25

512

125

475

330 m.

50

434

31

10

75

408

4

Stat. 91. July 29

0

846

10

100

399

5

Canso Strait

10

836

1

150

372

4

50 m.

20

835

3

200

352

3

30

832

1

300

325

40

831

312

DEPARTMENT OF THE NAVAL SERVICE

Table 2. — 'Depth of the Isosteric surfaces in metres. Spring cruises.

THE GULF OF ST. LAWRENCE.

and "B" denotes that the isosteric surface in question has intersected the surface or the bottom,
respectively, beyond the station.

Section I.

Section II.

Stat.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

14

15

16

17

18

160-

150-

ca.

Depth m.

69

45

25

21

31

61

76

92

300

250

51

140

200

40

40

85

260

130

64

vv = 900

*

*

2

0

6

0

4

*

*

*

*

*

*

3

3

*

*

*

*

VI = 800

*

*

10

B

16

5

13

0

*

*

*

*

2

6

6

*

*

*

*

VI = 700

*

*

B

B

24

9

19

13

*

*

*

*

11

10

10

15

*

*

*

VI = 600

30

33

B

B

B

24

24

20

11

9

13

R

21

16

16

25

*

*

*

i'l = .500

B

B

B

B

B

B

B

65

57

51

44

46

47

33

33

38

49

52

34

vi = 400

B

B

B

B

B

B

B

B

130

142

B

B

167

B

B

B

138

B

B

Section III.

Section IV.

Stat.

19

20

21

23

22

24

25

26

21

22

23

26

25

24

250-

ca.

ca.

82

55

40

63

40

27

195

355

389

271

45

400

500

100

*

41
B

*
*

*

40
B

*

*

29
B
B

*

13
20
B
B

*
*

22
34
B
B

*
0
6
17
B
B

*

3

12

19

47

111

*

9

14

21

49

135

6

18

26

39

139

*
*

20

27

50

136

j;i = 900

*

*

40
B

*
*

67
161

*

*
*
*

50
150

*

vi = 800

if

vi = 700

*

VI = 600

16

t)i = 500

37

V I = 400

B

CANADIAN FISHERIES EXPEDITION, ;9/.'/-/5

313

Table 2. — Depth of the Isosteric surfaces in metres. — Spring; cruises — Con.

THE NOVA SCOTIA AND NEWFOUNDLAND BANK.

1 SectioiV V.

Stat.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Depth in.

25

60

146

173

73

45

109

51

106

740

Over .500

i'l

= 600

= 500

12
B
B

17
B
B

1.3
.39
B

51
129

*
7
B

45
B

*

29
92

*

60
B

*

25
101

*
*
87

*
•
74

*

*

12c

*
«
) 5?

*
*
8f

*
*

93

*
*

7'1

= 400

70

Section \'I.

Section VII.

Stat.

16

17

17a 18

19

20

21

22

22

23

24

25

26 27

Depth m.

Over 500

91

116

73

73

100

120

124

Ov. 500.

/•j

= 600

*
*
70

*
41

*
51

*
»

73

*
*

68

*
*

B

*
*

86

*
*
B

*
*
B

*

B

*
*

B

*
106

5
93

*

= 500

*

I'l

= 400

81

Section VIII.

Section IX.

Stat.

27

28

29

30

31

32

33

33

34

35

36

Depth m.

i

Over 500

58

127

85

155

ca.
73

ca.
73

ca.
350

ca.
450

230

= 600

*
81

43
123

*

47

B

45
B

47
B

*

64
B

19
59
B

19
59
B

*

23
IPO

•

22
115

*

''1

= 500

18

Vl

= 400

•

158

6551—24

314

DEPARTMENT OF THE NAVAL ^ERTICE

Table 2. — Depth of the Isosteric surfaces in metres. Summer cruises.

THE GULF OF ST. LAWRENCE.

—

Section X.

Stat.

27

28

29

30

31

32

33

34

35

36

37

38

39

40

Depth m.

23

23

32

66

65

87

78

405

ca.
400

53

75

180

284

68

I), = 1100

*

8
14
18
B
B
B
B

B
B
B
B
B
B
B

2
11
14
23
B
B
B
B

*

1]
2(
3C
46
54
E
B

*

10
17
24
36
45
59
B

*
*
4
S

17
27
64
B

*
*

3
8
14
22
46
B

*
*
*
2
11
30
48
130

*
*
*
*

14

22

42

143

*

12
22
30
48
B

*

*

15

22
41
B

*
*
*

8

15

21

35

134

*
*

*

1

15

21

35

150

*

vi = 1000

«

ri = 900 ,

*

vi = 800

2

t)i = 700

7

vi = 600

12

n = 500

34

ti = 400

B

Section XI.

Seciton XII.

Stat.

40

41

42

43

44

45

46

47

48

49

50

54

58
50

59

275

*
*
*
*

10
20
46
B

91

Depth m.

68

189

90

265

157

380

ca.
455

410

175

75

42

110

50

vi = 1100

*
*
2
7
12
34
B

*

*
*

16

24

52

16''

*

*

15
28
49
B

*
*
*
*

15

25

49

154

*
*

*

15

24

46

152

*
*

*

*

30

57

198

*
*

*

25
45

149

i

*
*

6

24

42

69

148

*
*

8

18

31

50

115

*
*

13
18
23
31
61
B

*
*

16
26
32
39
B
B

*

6
7
9
11
21
61
B

*
*

*

11

21
45
B

*

vi = 1000

*

vi = 900

*

vi = 800

B

vi = 700

B

vi = 600

B

»i = 500

B

Di = 400

B

CANADIAN FISHERIES EXPEDITION, lOUflS

315

Table 2. — Depth of the Isosteric surfaces in metres. Summer cruises — Con.
THE NOVA SCOTIA AND NEWFOUNDLAND BANKS.

Section XIII.

Section XIV.

Stat.

37

38

39

40

41

42

43

44

44

45

46

47

48

49

Depth m.

62

170

95

134

420

Over 1000

Over 1000

144

246

135

- 700

«

14
B
B

3

35
75
B

*

41
64
B

5

17

37

112

*
*

35

89

*

0
37

78

«

5

53
143

*

28

55

105

*

28

55

105

*
*

47
117

*

25

41

113

*

9
49
94

7

30

45

106

8

- 600

25

- 500 ..

55

- 400

B

1

Section X'\

Section X\T

Stat.

49

50

51

52

53

54

55 56

56

57

58

59

60

62

63

64

65

Over

Depth m.

135

155

1.33

95

99

Over 1000 '

1000

187

45

98

62

55

120

105

i'\

= 700

8
25
55
B

3
22
43
113

*

25
37
94

«

15
37
92

*
5
31
B

*

16
36
66

2

16
34
72

7
18
33
97

7
18
33
97

*

16
38

82

*

13
37
96

*

22
B
B

*

18
43
B

«

31
58
B

*

21
49
B

13
38
67
B

15

i'i

= 600

29

7'l

= 500

69

ri

= 400

B

Section XVII.

Section XVIII.

Stat.

65

66

67

68

69

70

71 72

73

74

75

75

76

77

78

79

Depth m.

105

64

205

54

64

Over 1000

Over 1000

410

Vl

= 700

15

28

0

*

*

*

*

1

0

0

0

*

13

6

*

»

n

= 600

29

41

27

16

25

11

13

14

16

13

16

16

29

17

13

4

Vi

= 500

69

58

47

38

39

33

37

31

34

30

52

52

43

31

33

34

n

= 400

B

B

B

B

B

76

73

76

70

82

92

92

90

86

69

82

6551— 24i

316

DEPAETME'NT OF THE NAVAL SERVICE

Table 2. — Depth of the Isosteric surfaces in metres. Summer cruises — Con.

THE NOVA SCOTIA AND NEWFOUNDLAND BANKS — Concluded.

Section XIX.

Section XX.

Stat.

79

80

81

82

83

83

84

85

86

87

88

89

Depth m.

410

155

56

58

172

172

60

492

455

330

1.30

130

vi = 700

*

4
34

82

*

14
36
B

*

8

28
B

*

14
41
B

*

14
41
B

14
41
B

12
37
B

4
19
37
95

3

15
30
92

3
15
29
97

10
22
60
B

17

vi = 600

35

vi = 500

54

vi = 400

B

Table 3. — Form for calculation of amount of solenoids in the sea.

1

2

3

4

5

6

7

8

9

Depth

vu

1'35

a

Om

A

2A

aioo

2Aioo

0

25

50

75

100

300

522
498
469
461
453
3.39

514
497
462
431
417
329

r 8
r 1
r 7
r30
7-36
rlO

r 4-5

r 4

r 18-5
r 33
r 23

r 113
r 100
r 463
r 825
r 4600

r 6101
r 5988
r 5888
r 5425
r 4600
0

r 13

r 2
r 11
r 48
r 58
r 16

9840
96.58
9497
8750
7419
0

Table 4.- — Amount of solenoids between Stations IX. 34 and IX. 35.

Depth.

a

01 A

01 2A

Oiookm.

2Aiokm.

0

r 8
r 1
r 7
r 30
r 36
r 10

r 11
r 10
r 46
r 83

r 460

r 610
r 599
r 589
r 543
r 460
0

r 13

r 2
r 11
r 48
r 58
r 16

r 984

25

r 966

50

r 950

75

r 875

100

r 742

300

0

CANADIAN FISHERIES EXI'EIj}TIOy, 191.', 15

317

Table 5. — The Solenoids in Canadian waters.

Depth.

a.

01 A.

01 2A.

dlOOkm.

2 A lOkm

Sect. I, 5-6,

0

r 26

r353

r 55

r750

SE 70

47 km. 48 m.

rl08

10

rl89

rl50

r245

r402

r521

SE. 4-8

20

rll2

r 95

r 95

r238

r201

SE. 1-9

30

r 77

0

rl64

0

0

Sect. 16-7

0

I 25

I 329

I 46

I 607

N\V 5-6

54 km. 68 m.

I 92

10

; 157

/ 141

/ 237

Z 290

Z 438

NW.41

20

I 126

I 30

I 96

I 233

Z 178

NW.1.7

25

r 8

I 5

i 66

r 15

I 122

XVV.ll

30

I 28

Z 61

Z 52

Z 113

WV.IO

I 23

40

I 17

I 19

I 38

I 31

I 70

NW.0-7

50

I 21

Z 19

Z 19

Z 39

Z 35

NW.0-3

60

I 18

0

I 33

0

0

Sect. 1,7-8

0

r 132

r 542

r 231

r 951

SE 8-7

57 km., 78 m.

r 118

10

r 105

r 134

r 424

r 184

r 743

SE. 6-8

20

r 163

r 184

r 290

r 285

r 508

SE. 4-7

40

r 21

r 58

r 106

r 37

r 186

SE. 1-7

60

r 37

r 48

r 48

r 65

r 84

SE. 0-8

75

r 27

0

r 47

0

0

Sect 18-9

0

r 160

r 414

r 363

r 941

SE 8-7

44 km., 100 m.

r 241

25

r 33

r 123

r 173

r 75

r 393

SE. 3-6

75

r 16

r 50

r 50

r 36

r 114

SE. 10

100

r 24

0

r 54

0

0

Sect. I, 9-10

0

r 11

r 81

r 15

r 108

SE 10

75 km., 325 m.

r 29

25

r 12

r 24

r 52

r 16

r 69

SE. 0-6

50

r 7

r 33

r 28

r 9

r 37

SE. 0-3

75

r 19

r 25

I 5

r 25

Z 7

NW.Ol

100

r 1

/ 30

Z 30

r 1

Z 40

NW.O 4

150

/ 13

0

Z 17

0

0

318 DEPARTMETSIT OF THE NAVAL SERVICE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

0-1 A.

0-1 SA.

Oiookm.

2 A lOkm

u.

Sect. I, 10-11

0

r 14

r 97

r 50

r 346

SE. 31

28 km., 90 m.

r 48

25

r 25

r 49

r 49

r 89

r 175

SE. 1-6

50

r 14

0

r 50

0

0

Sect. I, 11-12

0

I 13

r 17

I 27

r 35

SE. 0-3

49 km., 90 m.

r 16

10

r 46

r 25

7- 1

r 94

r 2

SE. 0

25

I 13

I 24

I 24

Z 27

Z 49

NW.0-4

50

I 6

0

Z 12

0

0

Sect I 12-13

0

I 189

I 280

Z 348

Z 556

Z1023

NW.9-2

34 km., 250 m.

25

I 35

I 42

I 68

Z 103

I 200

NW.1-8

50

r 2

Z 26

r 6

I 76

NW.0-7

75

I 1

I 19

I 28

Z 3

Z 82

NW.0-7

100

I 14

/ 9

Z 9

Z 41

Z 26

NW.0-2

125

r 7

0

r 21

Z 0

0

Sect I 13-14 .

0

I ni

I 132

I 70

Z 432

Z 171

NW.1-5

41 km., no in.

20

T 45

r 62

r 62

r 110

r 151

SE. 1-4

35

r 38

0

r 93

0

0

Sept II 14-15

0

r 227

r lb

I 115

r 273

Z 139

NE. 1-3

83 km., 110 m.

10

I 11

I 89

i 190

Z 93

Z 230

NE. 2-1

20

I 101

i 101

Z 101

I 122

Z 122

NE. 11

40

0

0

0

0

0

Sect II 15-16

0

r 189

r 192

r 287

r 386

r 585

SW. 5-3

49 km., 180 m.

•

10

r 194

r 137

r 95

r 396

r 194

SW. 1-7

20

r 80

r 45

I 42

Z 163

Z 86

NE. 0-8

40

I 35

Z 54

Z 87

Z 71

Z 177

NE. 1-6

60

I 19

Z 33

I 33

Z 39

Z 67

NE. 0-6

80

I 14

0

Z 29

0

0

Sect II 16-17

0

r 16

r 28

Z 85

r 34

Z 181

NE. 1-6

47 km., 210 m.

25

r 6

Z 3

I 113

r 13

Z 241

NE. 2-2

50

I 8

Z 110

Z 17

Z 234

NE. 2-1

I 3C

75

I 16

i 4?

Z 80

Z 34

Z 170

NE. 1-5

100

I 20

Z 35

Z 35

Z 43

Z 75

NE. 0-7

125

I 8

0

Z 17

0

0

CANADIAN FISHERIES EXPEDITION, 191 } 15
Table 5. — The Solenoids in Canadian waters — Continued.

319

Depth.

a .

01 A.

oii:A.

aiookm.

2 A lOkn,

u.

Sect. II, 17-18

0

1

''6

r 53

I 100

r 204

SW. 1.8

26 km., 100 m.

I 10

25

r

18

r 63

r 63

r 69

r 242

S\V. 2.2

50

r

32

0

r 123

0

0

Sect. Ill 19-20

0

?

I 264

I 628

SE. 5-8

42 km., 130 m.

I 29

25

I

26

I 93

I 235

Z 62

Z 559

SE. 5-1

50

I

48

I 53

I 142

I 114

I 338

SE. 31

60

I

58

I 89

I 89

Z 1.38

/ 212

SE. 2-0

80

I

31

0

; 74

0

0

Sect. Ill 20-21

0

17

r 330

r 44

r 846

NW.7-8

39 km., 360 m.

r 39

25

r

14

r 66

r 291

r 36

r 746

NW.6-9

50

r

39

r 69

r 225

r 100

r 577

NW.5-3

75

r

16

r 31

r 156

r 41

r 400

NW.3.7

100

r

9

r 125

r 125

r 23

r 321

XW.30

200

r

16

0

r 41

0

0

Sect. Ill, 21-23

0

f

,10

r 6"^

Z 95

r 141

NW.IS

44 km., 400 m.

; 55

20

I

13

/ 0

r 117

I 30

r 266

NW.2-5

40

r

11

r 16

r 119

r 25

r 270

XW.2.5

50

r

22

r 48

r 103

r 50

r 234

NW.2.2

75

r

16

r 55

r 55

r 36

r 124

NW.ll

100

r

28

0

r 64

0

0

Sect. Ill, 2.3-22

0

r 9

r 45

r 82

XW.0.8

11 km., 70 m.

r 10

20

r

5

r 10

I 1

r 45

I 9

SE. 01

40

r

5

I 11

/ 11

r 45

/ 100

SE. 0.9

55

L

19

0

I 173

0

0

Sect. 111,22-24

0

I

lO"'

I 307

/ 1 i7

I 473

SE. 4-4

65 km., 4.5 m.

I 190

20

I

88

I 117

I 117

i 136

i 180

SE. 1-7

35

I

68

0

i 105

0

0

320

DEPARTMENT OF THE NAVAL SERVICE

Table 5. — The Solenoids in Canadian waters. — Continued

Depth .

a.

01 A.

0-1 2A.

fllOOkm.

2A lOkm

u.

Sect. Ill, 24-25

0

I 79

/ 27

Z 155

Z 53

SE. 0-5

51 km., 50 m.

I 77

10

I 74

/ 15

/■ 50

I 145

r 98

NW.0-9

20

r 44

r 47

r 65

r 86

r 127

NW.1-2

30

r 49

r 18

r 18

r 96

r 35

NW.0-3

35

r 24

0

r 47

0

0

Sect. Ill, 25-26

0

/ 36

/ 234

Z 54

Z 354

SE. 3-3

66 km., 60 m.

I 34

10

/ 32

I 75

I 200

Z 48

Z 303

SE. 2-9

20

/ 118

I 125

Z 125

Z 179

Z 189

SE. 1-8

35

/ 49

0

Z 74

0

Sect. IV, 21-22

0

I 21

/ 126

Z 300

Z1802

NW. 16-4

7 km., 50 m.

I 55

10

I 89

7 71

I 71

Z 1271

Z1015

NW.9-2

24

/ 12

( / J

0

Z 171

0

0

Sect. IV, 22-23

0

r 3

I 229

T 15

Z1145

NW. 10-4

20 km., 240 m.

I 3]

10

I 65

I 44

/ 198

Z 325

Z 990

NW.9-0

20

I 22

/ 20

I 1.54

Z 110

Z 770

NW.70

30

I 18

r 23

/ 134

Z 90

Z 670

NW.61

50

I 5

r 9

/ 111

Z 25

Z 555

NW.51

75

r 12

/ 0

I 120

r 60

Z 600

NW.5-5

100

/ 13

I 1
I 41

Z 118

Z 65

Z 590

NW.5-4

125

I 20

I 41

I 11

Z 100

Z 385

NW.3-5

150

I 13

^ 36

I 36

Z 65

Z 180

NW.1-6

190

I 5

0

Z 25

0

0

Sect. IV, 2.3-26

0

I 2

r 105

Z 11

r 553

SE. 50

19 km., 350 m.

r 5

10

r 13

Z 30

r 100

r' 68

r 526

SE. 4-8

20

I 74

7 Of;

r 130

Z 389

r 684

SE. 62

30

r 24

t Jo

r 59

r 155

r 126

r 816

SE. 7-4

50

r 35

r 59

r 96

r 184

r 505

SE. 4-6

75

r 12

r 22

r 37

r 63

r 195

SE. 1-8

100

r 6

0

r 15

r 32

r 79

SE. 0-7

150

I 6

I 10

r 15

Z 32

r 79

SE. 0-7

250

r 4

r 25

>• 25

r 21

r 132

SE. 1-2

350

r 1

0

r 5

0

0

CANADIAN FISHERIES EXPEDITION, lOl'rlo
Table 5. — The Solenoids in Canadian waters — Continued.

321

Depth.

a.

01 A.

01 2A.

dlOOkm.

2 A lOkm

u.

Sect. IV, 26-25

0

r 81

i 46

r .506

/ 289

NW.2-6

16 km., 256 m.

r 62

10

r 43

r 12

I 108

r 269

I 675

NW.61

20

/ 20

I 19

i 120

/ 125

i 750

NW.6-8

30

I 18

; K.'k

I 101

I 113

/ 631

\\V.5-7

50

I 37

L 00

I 65

; 46

i 231

I 288

NW.2-6

75

/ 15

/ 14

r 19

I 94

r 119

SE. 11

100

r 4

r 13

r 33

r 25

r 206

SE. 1-9

150

r 1

r 20

r 20

r 6

r 125

SE. 11

250

r 3

0

r 19

0

0

Sect. IV, 25-24

0.

r 103

r 318

r 936

r 2890

SE. 260

11 km., 130 m.

r 117

10

r 131

r 120

r 201

rll91

r 1827

SE. 16-4

20

r 109

r 56

r 81

r 991

r 736

SE. 6-6

30

r 3

r 25

r 25

r 27

r 227

SE. 20

42

r 38

0

r 345

0

0

Sect. V, 1-2

0

r 9

I 10

r 53

i 59

NE.0-6

17 km., 27 m.

r 9

10

r 8

I 19

^ 19

r 47

I 112

XE. 11

20

I 45

0

i 265

0

0

Sect. V, 2-3

0

I 3

r 143

i 8

r 376

SW. 3-7

38 km., 90 m.

i 2

10

/ 1

r 3

r 145

I 3

r 381

SW. 3.7

20

r 7

r 9^

r 142

r 18

r 373

SW. 3-7

30

r 42

r zo
r 49

r 117

r 110

r 308

SW. 30

40

r 56

r 68

r 68

r 147

r 179

SW. 1-8

55

r 34

0

r 89

0

0

Sect. V, 3-4

0

r 42

r 131

r 65

r 201

SW. 20

6.") km., 170 m.

r 41

10

r 40

r 37

r 90

r 62

r 139

SW. 1-4

20

r 34

r 9

r 53

r 52

r 82

SW. 0-8

30

I 16

I 21

r 44

Z 25

r 68

SW. 0-7

40

I 26

Z 22

r 65

i 40

r 100

SW. 10

50

I 17

I 4

r 87

I 26

r 134

SW. 1-3

60

r 9

r 91

r 14

r 140

SW. 1-4

r 19

75

r 16

r 25

r 72

r 25

r 111

SW. 1-1

90

r 17

r 47

r 47

r 26

r 72

SW. 0-7

110

r 30

0

r 46

0

0

322 DEPARTMENT OF THE NAVAL SERVICE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

01 A.

01 SA.

Oiookm.

SA lOkm

Sect. V, 4-5

0

r 59

r 406

r 106

r 725

SW. 7-2

56 km., 140 m.

r 63

10

r 66

r 105

r 343

r 118

r 612

SW. 61

25

r 74

r 146

r 238

r 132

r 425

SW. 4-2

50

r 43

r 92

r 92

r 77

r 164

SW. 1-6

70

r 49

0

r 88

0

0

Sect. V, 5-6

0

I 14

Z 121

Z 25

Z 216

NE. 21

56 km., 120 m.

I 17

10

I 21

Z 27

I 104

Z 38

Z 186

NE. 1-8

20

I 33

Z 37

Z 77

Z 59

Z 138

NE. 1-4

30

I 40

I 40

Z 40

Z 72

I 71

NE.0-7

40

I 40

0

Z 72

0

0

Sect. V 6-7

0

I 9

r 37

Z 16

7- 66

SW 0-7

56 km., 40 m.

Z 6

10

/ 3

I 1

r 43

Z 5

r 77

SW. 0-8

20

r 2

r 11

r 44

r 4

r 79

SW. 0-8

30

r 20

r 33

r 33

r 36

r 59

SW. 0-6

40

r 45

0

r 81

0

0

Sect. V, 6^

0

I 20

Z 28

Z 31

Z 44

N. 0-4

64 km., 40 m.

I 20

10

I 19

i 12

Z 8

Z 30

I 12

N. 01

20

I 5

r 4

Z 8

r 6

S. 01

30

r 7

r 3

r 3

r 11

r 5

S. 00

40

I 1

0

Z 2

0

0

Sect. V, 7-8

0

I 11

Z 124

Z 37

Z 413

W 4 1

30 km., 50m.

Z 14

10

/ 16

Z 11

Z 110

I 53

Z 366

W. 3-6

20

/ 7

I 10

Z 99

Z 23

I 330

W. 3-3

30

I 13

Z 30

Z 89

Z 43

Z 296

W. 2-9

40

I 46

I 59

Z 59

Z 153

I 196

W. 20

50

I 72

0

Z 240

0

0

Sect. V, 8-9

0

r 29

r 198

r 53

r 360

SW. 3-6

55 km., 50 m.

r 56

25

r 16

r 66

r 142

r 29

r 258

SW. 2-6

40

r 72

r 76

r 76

r 131

r 138

SW. 1-4

50

r 80

0

r 146

0

0

CANADIAX FISHERIES EXl'EDITIOX, 1914-15 323

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

0-1 A.

01 2A.

QlOOkm.

2) A l»km

n.

Sect. V, 9-10

0

r 22

r 5

r 73

r 17

SW. 0-2

30 km., 100 m.

r 59

25

r 25

I 6

Z 54

r 83

Z 180

NE. 1-8

50

I 30

7 i;!

I 48

i 100

I 160

NE. 1-6

75

/ 11

I 01

r 3

7- 3

I 37

r 10

SW. 01

100

r 13

0

r 43

0

0

Sect. V, 10-11

0

r 8

r 131

r 22

r 354

SW. 3-5

37 km., >400 m.

r 17

25

r 5

r 1

r- 114

r 14

r 308

SW. 31

50

I 4

r 38

r 113

i 11

r 305

SW. 3 0

75

r 34

r 55

r 75

r 92

r 203

SW. 20

100

r 10

r 55

r 20

r 27

r 54

SW. 0-5

150

r 12

r 45

I 35

r 32

I 95

NE. 0-9

300

I 6

I 80

Z 80

I 16

Z 216

NE. 21

400

I 10

0

i 27

0

0

Sect. V, 11-12

0

r 1

I 397

r 1

I 592

NE. 5-9

67 km., >400 m.

r 51

25

r 40

r 85

i 448

r 60

Z 817

NE. 8-2

50

r 28

r 10

Z 533

r 42

I 794

NE. 7-9

75

I 20

i 63

I 543

I 30

Z 809

NE. 8-1

100

I 30

I 150

/ 480

i 45

Z 715

NE. 7-2

150

I 29

i 270

I 330

I 43

I 492

NE. 4-9

300

I 7

I 60

Z 60

Z 10

Z 89

NE. 0-9

400

I 5

0

Z 7

0

0

Sect. V, 12-13

0

I 29

i 71

r 404

Z 104

rl442

SW. 14-4

28 km., >400 m.

25

I 28

i 4

r 475

Z 100

rl696

SW. 170

50

r 25

r 70

r 479

r 89

7-1710

SW. 17- 1

75

r 31

r 91

r 409

r 111

rl460

SW. 14-6

100

r 42

r 180

r 318

r 150

rll35

SW. 11-4

150

r 30

r 138

r 138

r 107

r 493

SW. 4-9

200

r 25

0

r 89

0

0

324

DEPARTMENT OF THE NAVAL SERVICE
Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

0-1 A.

0-1 2A.

OlOOkm-

2 A lOkrr

u.

Sect. V, 13-14

0

r 57

/ 79

r 83

I 115

NE. 1-2

69 km., >400 m.

r 91

25

r 16

I- 15

I 170

r 23

Z 247

NE. 2-5

50

I 28

I 89

Z 155

Z 41

Z 225

NE. 2-3

75

I 43

Z 53

I 66

I 62

Z 96

NE. 10

100

0

I 3

Z 13

0

Z 19

NE. 0-2

150

I 1

Z 10

Z 10

Z 1

Z 15

NE. 0-2

200

I 3

0

Z 4

0

0

Sect. V, 14-15

0

/ 21

Z 479

Z 21

Z 489

NE.4-9

98 km. >400 m.

Z 60

25

/ 27

I 38

Z 419

Z 28

I 427

NE. 4-3

50

I 3

Z 6

Z 381

Z 3

Z 388

NE. 3-9

75

I 2

/ 30

Z 375

Z 2

Z 382

NE. 3-8

100

I 22

/ 90

Z 345

Z 22

Z 351

NE. 3-5

150

I 14

I 180

Z 255

Z 14

Z 260

NE. 2-6

300

I 10

I 75

Z 75

Z 10

Z 77

NE. 0-8

400

I 5

0

Z 5

0

0

Sect. V, 15-16

0

r 61

Z 186

r 63

Z 192

NE. 1-9

97 km., >400 m.

r 159

25

r 61

r 113

Z 345

r 63

Z 355

NE. 3-6

50

r 29

r 78

Z 458

r 30

Z 472

NE. 4-8

75

r 33

r 39

Z 536

r 34

Z 552

NE. 5-6

100

I 3

I 120

Z 575

Z 3

I 592

NE. 60

200

/ 21

Z 230

Z 455

Z 22

Z 469

NE.4-7

300

I 25

I 225

Z 225

I 26

I 232

NE. 2-3

400

I 20

0

Z 21

0

0

Sect. VI, 16-17

0

r 4

r 3

r 6

r 4

E. 00

70 km., >400 m.

r 10

25

r 4

r 14

Z 7

r 6

Z 10

W. 01

50

r 7

r 12

Z 21

?• 10

Z 30

W. 0-3

75

r 3

Z 1

Z 33

r 4

Z 47

W. 0-5

100

I 4

Z 32

Z 6

I 46

W. 0-5

0

150

r 4

r 13

Z 32

r 6

Z 46

W. 0-5

200

r 1

Z 5

Z 45

r 1

Z 64

W. 0-6

300

I 2

I 40

Z 40

Z 3

Z 57

W. 0-6

400

I 6

0

I 9

0

0

CANADIAN FISHERIES EXPEDfJION, 191'/ J'>

325

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

01 A.

01 2A.

ClOOkm.

1

2 A .own,

u.

Sect. VI, 17-18

0

I

53

I 129

r 539

I

70

r 709

E.

71

76 km.. >400 m.

25

I

50

I 124

r 668

I

66

r 878

E.

8-8

50

I

49

I 61

r 792

I

65

rlOol

E.

10-5

/o

0

r 15

r 853

0

rll22

E.

11-2

100

r

12

r 72

r 838

r

16

rll02

E.

110

150

r

17

r 405

r 765

r

22

rl007

E.

101

300

r

37

r 360

r 360

r

49

r 474

E.

4-7

400

r

35

0

r

46

0

0

vSect. VI, 17a 18

0

I

24

I 139

I 159

I

83

/ 549

W.

5-4

29 km., >400 m.

75

I

13

I 20

I 20

I

45

I 69

W.

0-;

100

I

3

0

I

10

0

0

Sect VI 18-19

0

I

2

I 11

I 278

I

5

I 631

W.

6-2

44 km., >400 m.

25

I

/

I 19

I 267

I

16

/ 606

\\.

60

50

I

8

r 14

I 248

I

18

/ 563

W.

0 0

75

r

19

r 33

I 262

r

43

I 595

W.

b-9

100

r

7

r 8

I 295

r

16

; 670

W.

6-6

1.50

I

4

I 128

I 303

I

9

I 688

W.

6-8

300

I

13

/ 175

; 175

I

30

I 397

W.

3-9

400

I

22

0

I

50

0

0

Sect VI 19-20

0

1

1

I '>3

I

0

I 51

W

n-5

45 km., >400 m

r 1

25

r

2

r 14

I 24

r

4

I 53

W.

0-5

50

r

9

I 38

I 38

r

20

I 84

■\V.

OS

75

I

39

0

I

87

0

0

Sect VI 20-21

0

10

r 112

IS

r 200

F

1-9

56 km., 110 m.

r 39

25

r

21

r 43

r 73

r

38

r 131

E.

1-3

50

r

13

r 30

r 30

r

23

r 54

E.

0-5

75

r

11

0

r

20

0

0

Sect. VI, 21-22

0

I

7

I 38

I

16

I 89

■\\-

0-9

43 km., 85 m.

I 20

20

I

13

I 25

Z 18

I

30

I 42

W.

0-4

40

I

12

I 2

r /

I

28

r 16

E.

0-2

50

r

7

r 9

r 9

r

16

r 21

E.

0-2

65

r

5

0

r

12

0

0

326 DEPARTMENT OF THE NATAL SERVICE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth .

a.

01 A.

01 2A

aiookm.

2 A lOkn

M.

Sect. VII, 22-23

0

r 1

Z 31

r 1

I 5'^

SE 0-5

60 km., 80 m.

I 3

25

I 4

I IS

I 28

I 7

Z 47

SE. 0-5

50

/ 10

I 10

Z 10

Z 17

Z 17

SE. 0-2

60

I 10

0

Z 17

0

0

Sect. VII, 23-24

0

I 6

I 13

Z 11

I 24

SE 0-2

54 km., 140 m.

I 18

50

I 1

r 5

r 5

Z 2

r 9

NW. 01

75

r 5

0

r 9

0

0

Sect. VII, 24-25

0

r S

r 138

r 16

r 282

NW 2-7

49 km., 100 m.

r 65

50

r 18

r 73

r 73

r 37

r 149

NW.1-4

100

r 11

0

r 22

0

0

Sect. VII, 25-26

0

I 50

I 212

Z 81

I 341

SE 3-3

62 km., > 400 m.

I 98

25

I 28

I 84

Z 114

Z 45

Z 184

SE. 1-8

50

I 39

I 65

Z 30

Z 63

Z 48

SE. 0-5

100

r 13

r 35

r 35

r 21

r 56

NW.0-5

120

r 22

0

r 35

0

0

Sect. VII, 26-27

0

r 9

Z 147

r 15

Z 245

SE 2-4

60 km., >400 m.

r 23

25

r S

r 35

I 170

r 15

Z 284

SE. 2-8

50

r 19

r- 73

Z 205

r 32

I 342

SE. 3-4

100

r 10

I 33

I 278

r 17

Z 464

SE. 4-5

150

I 23

/ 210

Z 246

Z 38

Z 409

SE. 40

300

I 5

I 35

Z 35

Z 8

I 58

SE. 0-6

400

I 2

0

I 3

0

0

Sect. VIII, 27-28

0

I 44

Z 785

Z 105

Z 1868

SW 18-4

42 km., >400 m.

Z 116

25

I 49

Z 133

Z 669

Z 117

I 1592

SW. 15-6

50

I 57

I 126

I 536

Z 136

Z 1276

SW. 12-6

75

I 44

Z 107

Z 410

Z 105

Z 976

SW. 9-6

100

/ 42

I 115

Z 303

I 100

Z 721

SW. 7-1

150

I 4

Z 128

Z 188

Z 12

Z 447

SW. 4-4

300

I 13

Z 60

Z 60

Z 31

Z 143

SW. 1-4

400

r 1

0

r 2

0

0

CANADIAN FISHERIES f^.Xl'EDlTION, 19U Ij
Table 5. — The Solenoids in Canadian waters — Continued.

327

Depth.

a.

01 A.

01 2A.

fllOOkm.

2 A lOkm

Sect. VIII, 28-29

0

I 8

I 5

I 13

I 8

SW 01

61 km., 90 m.

I 5

50

r 6

0

r 10

0

0

Sect. VIII, 29-30

0

I 13

I 165

I 23

Z 289

SW 2 ■ 8

57 km., 60 m.

I 165

50

I 53

0

Z 93

0

0

Sect. VIII, 30-31

0

I 21

i 79

I 33

Z 123

SW 1 • 2

64 km., 140 m.

I 53

25

I 21

I 30

I 26

Z 33

Z 41

SW. 0-4

50

I 3

r 4

r 4

Z 5

r 6

XE. 01

75

r 6

0

r 9

0

0

Sect. VIII, 31-32

0

r 12

r 26

r 18

r 38

XE. 0-4

68 km.. 160 m.

r 54

25

r 31

r 8

Z 28

r 46

Z 41

SW. 0-4

50

I 24

I 36

i 36

Z 35

Z 53

SW. 0-5

75

I 5

0

Z 7

0

0

Sect. VIII, 32-33

0

I 58

I 148

Z 97

Z 247

SW 2-3

60 km., 75 m.

Z 121

25

I 39

I 48

Z 27

Z 65

Z 45

SW. 0-4

50

r 1

r 21

r 2

r 35

XE. 0-3

75

r 16

0

r 27

0

0

Sect. IX, 33-34

0

r 108

r 446

r 177

r 731

SE. 6-9

61 km., 180 m.

r 226

25

r 73

r 150

r 220

r 120

r 361

SE. 3-4

50

r 47

r 70

r 70

r 77

r 115

SE. 11

75

r 9

0

r 15

0

0

Sect. IX, 34-35

0

r 8

r 61C

r 13

r 984

SE. 9-2

62 km., >400m.

r 11

25

r 1

r 10

r 599

r 2

r 966

SE. 91

50

r 7

r 46

r 589

r 11

r 950

SE. 8-9

^0

r 30

r 83

r 543

r 48

r 875

SE. 8-2

100

r 36

r 460

r 460

r 58

r 742

SE. 70

300

r IC

0

r 16

0

0

Sect. IX, 35-36

0

I 7

I 155

Z 13

Z 282

XW. 2-6

55 km., 230 m.

Z 3

25

r 0

r 11

Z 152

r 9

Z 277

NW. 2-6

50

r 4

Z 13

I 163

r 7

I 297

XW. 2-8

75

I 14

; 150

Z 150

I 25

Z 273

XW. 2-5

150

I 26

0

Z 47

0

0

328

DEPARTMENT OF THE NAVAL SERVICE
Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

01 A.

)-lSA.

aiOOkm.

2 A lOkm

u.

Sect. X, 29-30

0

r 109

r 67

r 37

r 227

r 77

SE. 0-7

48 km., 50 m.

10

r 25

I 30

I 30

r 52

Z 62

NW. 0-6

25

I 65

0

I 135

0

0

Sect. X, 30-31

0

I 55

/ 24

r 325

Z 131

r 774

SE. 7-2

42 km., 60 m.

10

r 7

r 55

r 349

r 17

r 831

SE. 7-7

25

r 66

r 114

?• 294

r 157

r 700

SE. 6-5

40

/• 86

r 105

r 180

r 205

r 428

SE. 40

50

r 124

r 75

r 75

r 295

r 179

SE. \7

60

r 26

0

7- 62

0

0

Sect. X. 31-32

0

/■ 86

r 713

r 246

r2039

SE. 18-8

35 km., 60 m.

r 156

10

r 226

r 302

r 557

r 646

rl593

SE. 14-7

25

r 177

?• 248

r 255

7- 506

r 729

SE. 6-7

50

r 21

r 7

r 60

7- 20

SE. 0-2

60

/ 7

r 7

0

Z 20

0

0

Sect. X, 32-33

0

r 28

/• 253

r 56

r 506

SE. 4-7

50 km., 75 m.

r 25

10

r 22

r 47

r 228

r 44

r 456

SE. 4-2

25

r 40

r 83

r 181

r 80

7- 362

SE. 3-3

50

r 27

r 98

r 9R

r 54

r 196

SE. 1-8

75

r 51

0

r 102

0

0

Sect. X, 33-34

0

r 126

r 86

i 18

r 450

Z 64

NW. 0-6

28 km., 95 m.

10

r 46

/ 10

I 104

r 164

Z 371

NW. 3-4

25

/ 59

/ 73

/ 94

Z 211

Z 336

NW. 31

50

/ 1

I 21

? 21

Z 4

Z 75

NW. 0-7

75

/ 16

0

Z 57

0

0

Sect. X, 34-35

0

r 53

r 2

r 1

r 143

r 3

SE. 00

37 km., 390 m.

10

I 50

r 6

Z 1

Z 135

Z 3

NW. 00

25

r 58

r 96

I 7

7- 157

Z 19

NW. 0-2

50

r 17

r 28

1 103

r 46

Z 278

NW. 2-5

75

r 5

r 2

I 131

r 14

Z 354

NW. 3-2

100

I 4

I 43

Z 133

Z 11

Z 3.59

NW. 3-3

150

/ 13

Z 42

Z 90

Z 35

Z 243

NW. 2-2

200

I 4

i 30

I 48

Z 11

Z 130

NW. 1-2

300

/ 2

I 18

Z IS

Z S

Z 48

NW. 0-4

3.i0

1 ^

f

Z 14

0

0

CANADIAN FISHERIES EXFEDIIION, lOl.'f-lJ
Table 5. — The Solenoids in Canadian waters — Continued.

329

Depth.

a.

01 A.

01 ZA.

fllOOkm.

V A

u.

Sect. X, 35-36

0

I 52

Z 344

Z 113

I 746

NW. 6-8

46 km., 270 m.

I 61

10

I 70

I 127

Z 283

I 152

Z 614

NW. 5-6

25

I 99

I 156

I 156

Z 215

I 339

NW. 31

50

I 26

0

Z 56

0

0

Sect X 36-37

0

r 42

r 351

r 117

r 975

SE. 8-9

36 km., 50 m.

r 47

10

r 52

r 128

r 304

r 145

r 845

SE. 7-7

25

r 118

r 176

r 176

r 328

r 489

SE. 4-4

50

r 23

0

r 64

0

0

Sect. X 37-38

0

I 31

r 38

Z 76

r 92

SE. 0-8

41 km., 100 m.

I 27

10

I 23

r 9

r 65

Z 56

r 159

SE. 1-4

25

r 26

r 48

r 63

r 63

r 154

SE. 1-4

50

r 12

r 15

r 15

r 29

r 37

SE. 0-3

70

r 3

0

r 7

0

0

Sect X 38-39

0

r 15

Z 30

r 47

Z 94

NW. 0-8

32 km., 240 m.

r 11

10

r 7

»• 9

Z 41

r 22

Z 128

NW. 1-2

25

I 4

/ T

Z 43

Z 13

Z 134

NW. 1-2

50

0

I 4

I 38

0

I 119

NW. 11

75

/ 3

Z 4

Z 34

Z 9

Z 106

NW. 10

100

0

Z 20

Z 30

0

Z 94

NW. 0-8

150

/ 8

I 10

Z 10

Z 25

Z 31

NW. 0-3

175

0

0

0

0

0

Sect. X, 39^0

0

I 47

r 175

Z 127

r 473

SE. 4-2

37 km., 120 m.

r 64

10

r 175

r 135

r 111

r 473

r 300

SE. 2-7

25

r 5

Z 3

Z 24

r 14

Z 65

NW. 0-6

50

/ 7

/ 91

I 21

Z 19

Z 57

NW.0-5

65

I 21

0

Z 57

0

0

Sect. XI, 40-41

0

r 7'^

Z 390

r 141

Z 764

NE. 6-8

51 km., 100 m.

I 44

10

I 160

Z 176

Z 346

Z 314

Z 678

NE. 61

25

I 75

Z 138

Z 170

Z 147

Z 333

NE. 30

50

I 35

Z 32

Z 32

Z 69

Z 63

NE. 0-6

65

I 7

0

I 14

0

0

6551—25

330

DEPARTMENT OF THE NAVAL SERVICE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

01 A.

01 ZA.

OlOOkm-

."A lokm

M.

Sect. XI, 41-42

0

r 27

r 67

r 68

r 168

SW. 1-5

40 km., 80 m.

r 27

10

r 27

r 7

r 40

r 68

r 100

SW. 0-9

25

I 18

Z 13

7- 33

I 45

T 83

SW. 0-7

50

r 8

r 32

r 46

r 20

?• 115

SW. 1-0

75

r 18

r 14

r 14

r 45

r 35

SW. 0-3

85

r 9

0

r 23

0

0

Sect. XL, 42-43

0

0

r 14

0

r 27

SW. 0-2

52 km., 210 m.

0

10

0

r 11

r 14

0

r 27

SW. 0-2

25

r 14

r 18

r 3

r 27

r 6

SW. 01

50

0

Z 10

I \l

0

Z 29

NE. 0-3

75

I 8

I 5

I 5

Z 15

Z 10

NE. 01

85

I 2

0

Z 4

0

0

Sect. XI, 43-44 '.

0

I 4

r 22

Z 9

r 51

SW. 0-5

43 km., 210 m.

Z 4

10

I >?

r 26

Z 7

r 60

SW. 0-5

25

r 12

T i

r 29

r 19

r 28

?• 44

SW. 0-4

50

r 11

r 6

/ 10

r 26

Z 23

NE. C-2

75

I 6

I 11

I 16

Z 14

Z 37

NE. 0-3

100

I 3

/ 5

I 5

Z 7

Z 12

NE. 01

150

r 1

0

r 2

0

0

Sect. XII, 45-46

0

I 30

r 392

Z 107

r 1403

NW.130

28 km.. >400 m.

I 8

25

r 24

?• 75

T 400

?• 86

r 1432

NW.13-3

50

r 36

r 61

r 325

r 129

r 1164

NW.10-8

75

r 13

r 36

/• 264

r 46

r 945

NW.8-7

100

r 16

r 1.32

r 228

r 57

r 814

NW.7-5

150

r 37

r 175

r 95

T 132

r 339

NW.31

200

r 33

r 70

I 80

r 118

Z 286

SE. 2-6

300

I 19

Z 150

Z 150

Z 68

Z 536

SE. 50

400

I 11

0

Z 39

0

0

CANADIAN FISHERIES "^XrEDIflON, 1911,-15
Table 5. — The Solenoids in Canadian waters — Continued.

331

Depth

a.

01 A.

01 2: A.

fllOOkm-

2 A ,OUn.

u.

Sect XII 46-47

0

143

/ 299

I 941

/ .386

/ 2541

SE. 23-6

37 km., >400 m.

25

96

/ 214

/ 642

I 259

I 1735

SE. 161

50

75

/ 128

/ 428

I 203

/ 11.57

SE. 10-8

75

27

/ 50

I 300

I 73

/ 811

SE. 7-5

100

13

/ 40

I 250

/ 35

I 676

SE. 6-3

150

3

I 40

/ 210

I 8

Z 568

SE. 5-3

200

13

/ 115

/ 17C

I 35

I 4.59

SE. 4-3

300

10

I 55

I 55

I 27

/ 149

SE. 1-4

400

1

0

I 3

0

* 0

Sect. XII, 47-48

0

45

r 25

r 494

/ 110

r 1205

N\V. 11-2

41 km., 150 in.

25

65

r 149

r 469

T 159

r 1144

NW.10-6

50

54

r 111

r 320

r 132

r 781

NW. 7-3

75

r

35

r 74

r 209

r 85

r 510

NW. 4-7

100

r

24

r 13.^

r 135

r 59

r 329

MV. 31

150

r

30

0

r 73

0

0

Sect. XII, 48-49

0

I

^^'>

I 257

I 14£

/ 342

SE. 3-2

75 km., 120 m.

/ lO.-^

25

I

20

/ .56

/ 92

I 27

/ 122

SE. 11

50

I

25

/ 36

I 33

I 48

SE. 0-5

/ 36

70

I

11

C

I- n

0

0

Sect. XII, 49-50

0

31

I 26'^

r 44

/ 369

SE. 3-5

71 km., 60 m.

r 17

10

r

3

I 11^

I 27£

r 4

I 393

SE. 3-7

25

I

160

I 161

/ 161

/ 225

I 227

SE. 2-2

40

I

5c^

0

I 78

0

0

Sect. XIII, 37-38

0

I

.56

/ .340

I 147

/ 895

NE. 9 0

38 km., 90 m.

I 123

20

I

67

I 126

/ 217

/ 176

/ .571

XE. 5-7

40

I

62

I 88

I 88

I 163

I 232

NE. 2-3

60

I

26

C

I 68

0

0

Sect. XIII, 38-39

0

16

T 65

r 4''

r 171

SW. 1-7

38 km., 1.30 m.

r I

25

I

12

I 23

r 6C

I 32

/• 158

SW. 1-6

40

I

19

r S

r 83

I 50

r 218

SW. 2-2

50

r

36

r 68

r 75

r 95

r 197

SW. 20

75

r

18

r 7

r 47

r 18

SW. 0-2

90

I

9

0

; 24

0

0

6551— 25i

332 DEPARTMENT OF THE NAVAL SKRYICE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

01 A.

0-1 2A.

2A

Sect. XIII, 39-40...
38 km., 115 m.

0
25
40
50

75
90

I 45
r 111

r 113

r 55
r 58
r 65

r 82
r 168
r 84
r 142
r 92

r 568
r 486
r 318
r 234
r 92
0

I 118
r 292
r 297
r 145
r 153
r 171

r 1495
r 1278
7- 836
r 616
.r 242
0

SW. 15-1
SW. 12-9

SW. 8-4

SW. 6-2

SW. 2-4

0

Sect. XIII, 40-41 ....
38 km., 270 m.

0
25
50

75
100
125

r 144
I 20

r 46
r 15
r 18
r 13

r 155
r 33
r 76
r 41
r 39

r 344
r 189
r 156
r 80
r 39
0

r 379
Z 53
r 121
r 39
r 47
r 34

r 905
r 497
r 410
r 210
r 103
0

SW. 9-2
SW. 51
SW. 4-2
SW. 21

SW. M
0

Sect. XIII, 41-43

38 km., >400 m.

0

25
50
75
100
150
200
300
400

I 5
I 3
I 16

I 10

I 24

I 10

r 15

r 23

7- 30

r 35

Z 10

r 49

r 59

r 83

r 93

?• 78

r 55

r 25

Z 10
0

I 13

Z 8

I 42

r 21

r 11

r 13

r 18
0

I 5

r 129
r io.j
r 218
r 245
7- 205
r 145
r 66
Z 26
0

SW. 1-3
SW. i-o
SW. 2-2
SW. 2-5
SW. 21
SW. 1-5
SW. 0-7
NE. 0-3
0

Sect. XIII, 42-43

39 km., >400m.

0
25
50
75
100
150
200
300
400

I 10

I 9

I 73

I 28

I 36

I 25

I 32

I 17

I 12

I 24

Z 103

Z 126
Z

Z 152

Z 143

Z 245

Z 145

Z 1018
Z 994
Z 891
I 765
Z 685
I 533
Z 390
Z 145
0

I 26

Z 23

I 187

Z 72

Z 92

Z 64

Z 82

I 44

Z 31

Z 2610
Z 2549
Z 2284
Z 1961
Z 1756
Z 1366
Z 1000
Z 372
0

NE. 26-9
NE. 26-3
NE. 23-5
NE. 20-2

NE. 18 1

NE. 14 1

NE. 10-3

NE. 3-8

0

CANADIAN FISHERIES EXJ'EDITION, 191.>rl5

333

Table 5. — Tiie Solenoids in Canadian waters — Continued.

Depth.

a.

01 A.

01 Z A.

dlOOkm-

2) A lOkm

u.

Sect. XIII, 43^4

0

I 37

r 323

l 95

r 828

SW. 8-6

39 km., >4C0 iii.

I 109

25

I 50

Z 68

r 432

Z 128

r 1107

SW. 11-5

50

I 4

I 24

r 500

I 10

r 1282

SW. 13-3

75

I 15

r 9

r 524

Z 38

r 1343

SW. 14 0

100

r 22

r 95

r 515

r 56

r 132C

SW. 13-7

150

r 16

r 95

r 420

r 41

r 1077

SW. 11-2

200

r 22

r 180

r 325

r 56

T 833

SW. 8-7

300

T 14

r 145

r 14i

r 36

r 372

SW. 3-9

400

r 15

0

r 38

0

0

Sect. XIV, 44r-45

0

r 58

r 456

r 70

r 549

E. 5-7

83 km.. >400m.

r 118

25

r 36

r 11

r 338

r 43

r 407

E. 4 2

50

r 24

r 43

r 263

r 29

r 317

E. 3-3

75

T 11

r 4

r 219

r 13

r 264

E. 2-7

100

I 8

Z 25

r 215

Z IC

r 259

E. 2-7

1.50

I 2

7 e

r 240

Z 2

r 289

E. 30

200

0

r 100

r 245

0

7- 295

E. 30

300

r 20

r 145

r Hi

r 24

r 175

E. 1-8

400

r 9

0

r 11

0

0

Sect. XIV, 45^6

0

I 107

Z 138

I 192

Z 246

W. 2-5

56 km., >400 m.

I 163

25

I 23

7- 31

r 25

Z 41

r 45

E. 0-5

50

r 48

r 80

/ 6

r 86

Z 11

W. 01

75

T 16

r 22

I 86

r 29

Z 154

W. 1-6

100

T 1

7- 20

I 108

r 2

I 193

W. 20

150

r 7

r 12

Z 128

r 13

Z 229

W. 2-3

200

I 2

Z 35

/ 140

Z 4

Z 250

W. 2-6

300

I 5

I 105

I 105

I 9

Z 187

W. 1-9

400

I 16

0

Z 29

0

0

Sect. XIV, 46-17

0

r 85

r 129

r 72

r 100

r 85

E. 0-9

85 km., 150 m.

25

r 18

Z 47

/ 57

r 21

I 67

W. 0-7

50

i 56

I 64

I 10

Z 66

Z 12

W. 01

75

r £

r 23

r 54

r 6

r 64

E. 0-6

100

r 13

r 31

r 31

r 15

r 36

E. 0-4

125

r 12

C

r 14

0

334 DEPAIiTMi:NT OF THE XATAL SKIiVlCE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

0-1 A.

01 2A.

aiOQkm.

SA lOkm

u.

Sect. XIV, 47^8

0

I 114

I 282

Z 154

Z 381

W. 40

74 km., 170 m.

I 20.5

25

/ 50

Z 25

I 77

Z 68

Z 104

W. 1-2

50

r 30

r 6

Z 52

r 41

Z 70

W. 0-9

75

I 26

I 47

/ 58

Z 35

I 78

W. 0-8

100

/ 11

/ 11

I 11

Z 15

Z K

W. 01

125

r 2

0

r 3

C

0

Sect. XIV, 48^9

0

I 26

r 10

I 370

Z 36

I 514

W. 50

72 km., 180 m.

25

r 34

r 39

Z 380

r 47

Z 528

W. 5-2

40

r 18

I 9

/ 419

r 25

Z .582

VV. 5-7

50

I 36

I 99

/ 410

Z 50

Z 570

W. 5-6

75

I 43

I 1.35

/ 311

Z 60

Z 432

W. 4-2

100

/ 6-

/ 176

/ 176

Z 9C

Z 244

W. 2-4

125

l 76

0

Z 106

C

0

Sect. XV, 49-.50

0

r 36

r 517

r 103

r 1477

SW. 14-5

35 km., 130 m.

r 59

25

r 11

r 60

r 458

r 31

r 1309

SW. 12-8

50

r 37

r 103

r 398

7- 106

r 1138

SW. 11-2

75

r 46

r 138

r 294

r 132

r 84C

SW. 8-2

100

r 64

r 156

r 1.56

r 183

r 446

SW. 4-4

125

r 61

0

r 174

0

0

Sect. XV, 50-51

0

r 26

r 112

;• 59

r 25.5

SW. 2-5

44 km., 180 m.

r 1,';

25

I 14

I 3

r 97

Z 32

r 220

SW. 2-2

50

r 12

r 39

r 100

r 27

r 227

SW. 2-2

75

/• 19

r 40

r 6!

r 43

r 138

SW. 1-4

100

r 13

r 21

r 21

r 30

r 48

SW. 0-5

125

r 4

(1

r 9

0

0

Sect. XV, 51-52

0

r 43

r 94

r 74

7- 95

r 164

SW. 1-6

45 km., 120 m.

25

r 32

r 16

Z 20

r 71

Z 44

NE. 0-4

40

/ 11

/ 6

Z 36

Z 24

Z 80

NE. 0-8

50

/ 2

/ 20

I 30

Z 4

Z 67

NE. 0-7

75

/ IS

/ 10

Z 10

Z 29

Z 22

NE.0-2

90

0

0

C

0

0

CANADIAN FISHERIES K'XPEDI flON, 1911,-15 335

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

01 A.

01 2A.

aiOOkm.

SAlOkm

u.

Sect. XV, 52-53

0

r 27

r 83

r 163

r 77

r 466

SW. 4-7

35 km., 90 m.

25

r 39

r 52

r 80

r 112

r 229

SW. 2-3

40

r 30

r 21

r 28

r 86

r 80

SW. 0-8

50

r 12

r 18

r 7

r 34

r 20

SW. 0-2

75

r 2

; 11

/ 11

r 6

I 31

NE. 0-3

90

I 17

0

Z 49

0

0

Sect. XV, 53-.54

0

I 52

r 36

Z 127

r 89

SW. 0-9

41 km., 105 m.

; 106

25

I 33

I 13

r 142

Z 81

r 351

SW. 3-5

50

r 23

r 80

r 155

r 56

r 378

SW. 3-8

75

r 41

r 75

r 75

r 100

r 183

SW. 1-8

95

r 34

0

r 83

0

0

Sect. XV, 54-55

0

I 42

Z 443

Z 120

Z 1265

NE. 12-8

35 km., >400m.

Z 19

25

r 27

r 15

Z 424

r 77

Z 1211

NE. 12-2

50

I 15

I 29

Z 439

Z 43

Z 1254

NE. 12-7

75

/ 8

Z 20

Z 410

Z 23

Z 1171

NE. 11-8

100

I 8

I 30

Z 390

Z 23

Z 1114

NE. 11-3

150

I 4

Z IS

Z 360

Z 11

Z 1028

NE. 10-4

200

I 2

Z 1.50

Z 345

Z 6

Z 986

NE. 100

300

I 28

I 195

Z 195

Z 80

Z 557

NE. 5-6

400

I 11

0

Z 31

0

0

S3fc. XV^, 55-56

0

I 56

Z 66

Z 336

Z 116

Z 700

NE. 7 1

4S km., >400 m.

.

25

r 3

r 8

Z 270

r 6

Z 563

NE. 5-7

50

r 3

Z 5

Z 278

r 6

Z 579

NE. 5-9

100

i 5

Z 273

Z 10

Z 569

NE. 5-8

Z 40

150

^ 11

Z 68

Z 233

Z 23

Z 485

NE. 4-9

200

I 16

Z 165

I 33

I 343

NE. 3-5

300

r 1

Z 75
Z 90

Z 90

r 2

Z 187

NE. 1-9

400

I 19

0

Z 40

0

0

336 DEPARTMENT OF TEE NAYAL SERVICE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth .

0.

0-1 A.

0-1 2A.

fllOOkm-

SA lokm

u.

Sect. XVI, 56-57

0

r 89

r 711

r

116

r 924

E.

9-4

77 km., >400m.

r 86

25

I 20

Z 48

r 625

Z

26

r 812

E.

8-2

50

I 18

I 15

r 673

Z

23

r 874

E.

8-9

100

r 12

r 70

r 688

r

16

r 894

E.

9-1

150

r 16

r 113

?• 618

r

21

r 803

E.

8-2

200

r 29

r 255

r 505

r

38

r 656

E.

6-7

300

r 22

r 250

7- 250

r

29

r 325

E.

3-3

400

r 28

0

r

36

0

0

Sect. XVI, 57-58

0

r 21

Z 108

r

45

Z 230

W.

?-3

47 km., >400 m.

r 30

25

r 3

r 13

Z 138

r

6

Z 293

W.

2-9

50

r 7

I 31

Z 151

r

15

I 321

W.

3-2

75

I 32

Z 49

Z 120

I

68

Z 255

W.

2-6

100

/ 7

Z 45

Z 71

I

15

Z 151

W.

1-5

150

I 11

I 26

Z 26

I

23

Z 55

W.

0-6

175

I 10

0

I

21

0

0

Sect. XVI, 58-59

0

r 16

Z 20

Z 139

r

34

Z 296

W.

30

47 km., 70 m.

15

I 42

Z 59

Z 119

I

89

Z 253

W.

2-5

30

I 36

Z 60

Z 60

I

77

Z 128

W.

1-3

45

I 44

0

I

94

0

0

Sect. XVI, 59-60

0

I 26

Z 2

r 51

I

47

r 91

E.

0-9

56 km., 60 m.

15

r 24

r 28

r 53

r

43

r 94

E.

0-9

30

r 13

r 25

r 25

r

23

r 44

E.

0-4

45

r 20

0

r

36

0

0

Sect. XVI, 60-62

0

I 23

Z 109

Z 287

I

43

Z 542

W.

5-3

53 km., 90 m.

25

I 64

Z 134

I 178

I

121

Z 336

W.

3-3

50

I 43

Z 44

Z 44

I

81

Z 83

W.

0-8

60

Z 45

0

I

85

0

0

Sect. XVI, 62-63

0

Z 2

r 64

r 150

I

12

r 882

E.

8-6

17 km., 50 m.

25

r 53

r 86

r 86

r

312

r 506

E.

4-9

50

r 16

0

r

94

0

0

CANADIAN FISHERIES EXI'EhlTWN, lOUflS

Table 5, — The Solenoids in Canadian waters — Continued.

337

Depth.

a.

01 A.

01 2A.

aiookm-

2 A lOkm

Sect. XVI, 63-64

0

I 61

Z 318

Z 160

I 837

W. 8 1

38 km., 150 m.

I 163

25

I 69

I 155

I 155

/ 181

; 408

W. 4 0

50

I 55

0

I 145

0

0

Sect. XVI 64-65

0

I 39

I 5

r 66

Z 163

r 277

E. 2-7

24 km., 130 m.

25

r 3£

r 96

T 71

r 146

r 296

E. 2-9

50

T 42

r 26

Z 2J

r 175

Z 104

W. 10

75

I 21

/ 51

I 51

I 88

I 212

W. 20

100

/ 20

0

Z 83

0

0

Sect. XVII, 65-66

0

r 61

Z 189

r 203

Z 630

NE. 60

30 km., 130 m.

r 40

10

r 19

I 67

I 229

r 63

I 763

NE. 7-3

25

I 108

Z 162

Z 360

Z 540

NE. 5-2

Z 159

50

I 19

I 3

Z 3

I 63

Z 10

NE.Ol

60

r 13

0

r 43

0

0

Sect. XVII, 66-67

0

r 33

r 365

r 49

r 545

SW. 5-3

67 km., 90 m.

r 31

10

r 30

r 108

r 334

r 45

r 499

SW. 4-8

25

T 115

r 196

r 225

r 171

r 336

SW. 3-3

50

r 42

r 29

r 29

r 63

7- 43

SW. 0-4

60

r IS

0

r 22

0

0

Sect. XVII, 67-68

0

T 26

T 35

r 255

r 46

T 447

SW. 4-4

57 km., 140 m.

10

r 43

r 102

r 220

r 75

r 386

SW. 3-8

25

r 93

r 118

r 118

r 163

r 207

SW. 20

50

r 1

0

r 2

0

0

Sect. XVII, 68-69

0

I 20

I 28

/ 167

Z 45

Z 379

NE. 3-7

44 km., 70 m.

10

I 37

/ 89

I 139

Z 84

Z 316

NE. 31

25

I 82

I 55

Z 50

I 186

Z 114

NE. 11

40

T 9

r 5

r 5

r 20

r 11

SW. 01

50

r 1

0

r 2

0

0

Sect. XVII, 69-70

0

r 34

r 133

r 277

r 69

r 565

SW'. 5o

49 km., 130 m.

25

r 72

r 144

r 144

r 147

r 294

SW. 2-9

50

T 43

0

r 88

0

0

338

DEPARTMENT OF THE NATAL SERVICE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

a.

01 A.

0-1 2A.

aiOOkn..

2 A lOkni

M.

Sect. XVII 70-71

0

0

I 21

I 45

0

Z 155

NE 1-5

29 km., >400m.

25

I

17

I 30

I 24

I 58

I 82

NE. 0-8

50

I

7

I 3

r 6

Z 24

r 21

SW. 0-2

75

r

5

r 9

r 9

r 17

r 31

SW. 0-3

100

r

2

0

r /

0

0

Sect XVII 71-72

0

I

■19

r 21

Z 233

r 100

SW 10

21 km., >400 m.

/ 32

25

r

24

T 53

r 53

r 114

r 250

SW. 2-5

50

r

18

r 16

0

r 86

0

0

75

I

5

/ 16

I 16

I 24

Z 76

NE. 0-8

100

I

8

0

Z 38

0

0

Sect. XVII, 72-7.3

0

r

5

I 3

r 26

Z 16

NE. 0-2

19 km., >400 m.

I 16

25

I

18

I 15

r 13

I 95

r 68

SW. 0-7

50

r

6

r 17

T 28

r 32

r 147

SW. 1-5

75

r

7

r 11

r 11

T 37

r 58

SW. 0-6

100

r

2

0

r 11

0

0

Sect. XVII, 73-74

0

r

6

r 11

r 30

r 55

SW. 0-5

20 km., >400 m.

r 35

.5

r

22

I 24

r 110

Z 120

NE. 1-2

50

I

5

I 17

I 45

Z 25

Z 225

NE. 2-2

.75

L

9

I 28

/ 28

I 45

Z 140

NE. 1-4

100

I

13

0

Z 65

0

0

Sect. XVII, 74-75

0

r

48

I 238

r 123

Z 610

NE. 61

39 km., >400 m.

r 21

25

I

31

I 1.35

I 259

I 79

Z 664

NE. 6-6

50

I

77

I 109

Z 124

Z 197

Z 318

NE. 3-2

75

i

10

I IS

Z 1.5

I 26

Z 38

NE. 0-4

100

I

2

I 20

0

Z 5

0

0

150

I

6

/ 10

r 20

Z 15

r 51

SW. 0-5

200

r

2

r 20

r 30

r 5

r 77

SW. 0-8

300

r

2

?• 10

r 10

r 5

r 26

SW. 0-3

400

0

0

0

0

CANADIAN FISHERIES EXI-EDl'liON, IDUflS
Table 5. — The Solenoids in Canadian waters — Continued.

339

Depth,

a.

01 A.

01 2A.

QlOOkm.

2 A lOkm

u.

Sect. XVIII, 75-76

0

I

126

r 379

I 203

r 611

SE. 61

62 km.. >400 m.

I 255

25

I

78

I 29

r 634

; 126

rl024

SE. 10-2

50

r

55

r 64

r 663

r 89

rl069

SE. 10 6

75

I

4

r 1

r 599

I 6

r 966

SE. 9-6

100

r

5

r 60

r 598

r 8

r 964

SE. 9-6

150

r

19

r 113

r 538

r 31

r 867

SE. 8-6

200

r

26

r 240

r 425

r 42

r 685

SE. 6-8

300

r

22

r 185

r 185

r 35

r 298

SE. 30

400

r

15

0

r 24

0

0

Sect. XVIII, 76-77

0

r

28

r 277

r 4c

r 440

SE. 4-3

63 km., >4()0 m.

r 164

25

r

103

r 151

r 113

r 164

r 180

SE. 1-8

50

r

18

r 35

I 38

r 29

i 60

NW. 0-6

75

r

10

r 10

I 73

r 16

/ 116

NW. 11

100

I

2

I 5

I 83

i 3

/ 132

NW. 1-3

150

0

I 78

0

I 124

NW. 1-2

I 8

200

I

3

I 35

i 70

/ £

I HI

NW. 11

300

I

4

I 35

I 35

/ 6

Z 56

NW.0-6

400

I

3

0

Z 5

0

0

Sect. XVIII, 77-78

0

r

80

r 313

r 286

rlll7

SE. 110

28 km., >400 m.

r 238

50

r

15

r 34

r 75

r 54

r 268

SE. 2-6

75

r

12

r 41

r 41

r 43

r 146

SE. 1-4

100

r

21

0

r 75

0

0

Sect. XVIII, 78-7!)

0

r

50

r 30

I 62

r 147

I 182

NW. 1-8

34 km., >40() m.

50

38

r 63

Z 92

I 112

Z 271

NW. 2-6

75

12

I 29

i 29

/ 35

I 85

NW. 0-8

100

11

0

/ 32

C

0

Sect. XIX, 79-80

0

20

I 31

/ 329

I 34

i 558

SW. 5-4

59 km., 250 m.

10

42

I 59

I 298

Z 71

I 505

SW. 4-9

25

36

/ 31

/ 239

/ 61

/ 405

SW. 3-9

50

11

r 8

/ 208

r 19

Z 353

SW. 3-4

75

5

; 38

/ 216

I f

I 366

SW. 3-6

100

26

I 178

I 178

/ 44

Z 302

SW. 2-9

150

45

0

/ 76

0

1

0

340 DEPARTMENT OF THE NATAL SERVICE

Table 5. — The Solenoids in Canadian waters — Continued.

Depth.

0.

01 A.

01 2A.

aiookm.

2 A lokm

M.

Sect XIX 80-81

0

r 26

r 23

r- 121

T 42

r 195

NE. 1-9

62 km., 65 m.

10

r 19

r 54

r 98

r 31

r 158

NE. 1-5

25

r 53

r 50

7- 44

r 85

T 97

NE. 0-9

40

r 14

Z 6

Z 6

r 23

Z 10

SW. 01

54

I 22

0

Z 35

0

0

Sect XIX 81-82

0

I 5

Z 140

Z 11

Z 318

SW. 3 0

44 km., 60 m.

I 12

10

I 19

Z 47

Z 128

Z 43

Z 291

SW. 2-8

25

I 43

Z 66

Z 81

Z 98

Z 184

SW. 1-7

40

I 45

I 15

Z 15

Z 102

Z 34

SW. 0-3

50

r 16

0

r 36

0

0

Sect XIX 82-83

0

I 9

Z 99

Z 22

Z 241

SW. 2-3

41 km., 140 m.

Z 48

25

I 29

Z 51

Z 51

Z 71

Z 124

SW. 1-2

50

I 12

0

Z 29

0

0

Sect. XX, 83-84

0

r 15

r 118

r 29

r 231

N\V. 2-2

51 km., 64 m.

r 57

25

r 30

r 61

r 61

r 59

r 120

NW. 11

50

r 19

0

r 37

0

0

Sect. XX, 84-85

0

I 114

Z 178

Z 233

Z 363

SE. 3-4

49 km., 60 m.

Z 144

20

I 30

Z 28

Z 34

Z 61

Z 69

SE. 0-7

40

r 2

Z 6

Z 6

r 4

Z 12

SE. 0-1

50

I 14

0

Z 29

0

0

Sect XX 85-86

0

I 2

r 61

r 155

Z 5

r 352

NW. 3-3

44 km., >400 m.

25

r 51

r 80

r 94

r 116

?• 213

NW. 20

50

r 13

r 36

r 14

T 30

T 32

NW. 0-3

75

r 16

r 15

I 22

r 36

Z 50

SE. 0-5

100

I 4

r 5

Z 37

Z 9

Z 84

SE. 0-8

150

r 6

r 3

Z 42

r 14

Z 95

SE. 0-9

200

I 5

Z 35

Z 45

Z 11

Z 102

SE. 10

300

I 2

Z 10

Z 10

Z 5

Z 23

SE. 0-2

400

0

0

0

0

0

CANADIAN FISHERIES EXPEDITION, lDI',-lo 341

Table 5. — The Solenoids in Canadian waters — Continued.

Dopth.

a.

01 A.

01 ZA.

aiOOkm.

2 A ,0..

Sect. XX, 86-87

0

0

r 4

I 40

0

I 108

SE. 10

37 km.. >400 m.

25

r

3

r 10

I 44

r 8

Z 119

SE. 11

50

r

5

I 1

I 54

r 14

Z 146

SE. 1-4

75

I

6

I 53

I 16

I 143

SE. 1-4

I 8

100

0

I 45

0

Z 122

SE. 1-2

150

I

10

7 9T

I 20

Z 27

Z 54

SE. 0-5

200

0

r 5

r 5

0

r 14

NW. 01

300

r

1

0

r 3

0

0

Sect. XX, 87-88

0

I

66

I 159

I 800

Z 129

Z 1569

SE. 151

51 km., 125 m.

25

I

61

I 173

I 611

I 120

Z 1257

SE. 12]

50

I

78

I 192

I 468

Z 153

Z 917

SE. 8-8

75

I

75

I 165

Z 276

I 147

Z 541

SE. 5-2

100

I

0/

I 111

I 111

Z 112

Z 218

SE. 21

125

I

32

0

Z 63

0

0

Sect. XX, 88-89

0

r

17

I 94

Z 332

r 40

I 772

SE. 7-4

43 km., 125 m.

25

I

92

I 104

I 238

Z 214

Z 5.54

SE. 5-3

50

r

9

r 10

Z 134

r 21

I 312

SE. 3 0

10

I

1

I 36

I 144

Z 2

Z .^5

SE. 3-2

100

I

28

I 108

Z 108

Z 65

Z 251

SE. 2-4

125

I

58

0

I 135

0

0

342

DEPARTMENT OF THE NATAL SERVICE

Table 6. — The amount of solenoids per 10 km., equivalent to a velocity of the
current of 1 cm /sec, at different latitudes.

^

0

1

2

3

4

5

6

7

8

9

0

0
25
50
73
94
112
126
137
144

3

28
52
75
96
113
128
138
144

5
30
55
77
98
115
129
139
144

8
33
57
79
100
116
130
139
145

10
35
59
82
101
118
131
140
145

13

38

62

84

10.

119

132

141

145

15
40
64
86
105
121
133
142
145

18
43
66
88
107
122
134
142
146

20
45
68
90
108
124
135
143
146

23

10

48

20

71

30

92

40

110

50

125

60

136

70

143

80

146

Table 7. — Correction in cm. of level of water under atmospherical pressure.

(a) MILLIBAR.

m.bar.

940

950

960

970

980

990

1000

1010

1020

1030

1040

0

1

2

3

4

5

6

7

8

-60

-59

-58

-57

-56

-55

-54

-53

-52

-50

-49

-48

-47

-46

-45

-44

-43

-42

-40

-39

-38

-37

-36

-35

-34

-33

-.32

-30

-29

-28

-27

-26

-25

-24

-23

-22

-20

-19

-18

-17

-16

-15

-14

-13

-12

-10

- 9

- 8

- 7

- 6

- 5

- 4

- 3

- 2

0

1

2

3

4

5

6

7

8

10

11

12

13

14

15

16

17

18

20

21

22

23

24

25

26

27

28

30

31

32

33

34

35

36

37

38

40

41

42

43

44

45

46

47

48

-51
-41
-31
-21
-11
- 1
9
19
29
39
49

CANADIAN FISHERIES EXPEDITION, 191J,-i5

343

Table 7. — Correction in cm. of level of water under atmospherical pressure —

Concliifled.

(6) MILLIMETER Hg.

mm.

0

1

2

3

4

5

6

7

8

9

700

-66
-53
-40
-27
-13

-65
-52
-38
-25
-12

-64
-50
-37
-24
-11

-62
-49
-36
-21
- 9

-61

-48
-34
-25
- 8

-60
-46
-33
-21
— 7

-58
-45
-32
-19
- 5

-57
-44
-31
-17
- 4

-56
-42
-29
-16
- 3

-54

710

—41

720

-28

730

— 15

740

- 1

750

0

1

3

4

5

7

8

9

10

12

760

13

14

16

17

18

20

21

22

24

25

770

26

28

29

30

32

33

34

36

37

38

780

40
53

41

54

42
55

44
57

45

58

46
59

48
61

49
62

50
63

51

790

65

(c) Vio OF AN INCH Hg.

in

0

1

2

3

4

5

6

7

8

9

28

-51

-18

16

-48

-14

19

-45

-11

22

-41

- 8

26

-38

- 4

29

-35

- 1

33

-31

2

36

-28

6

39

-25

9

43

-21
12
46

29

30

PL. 1

PL. 2 Salinity. Spring Cruises

I I Coastal water < 30%'o

' I Intermediate water 30— 32%'o

I I Ba n k wate r 32-33 %„

BB Slope water 33— 35%''„

Hi Atlantic water > 35%,,

Sect. I— III, C.G.S. "Princess"
" IV, % "33"
" V-IX, C.G.S. "Acadia"

n 1^

m

-m

'^

^ V

vvni

^n

vr

Scale of depth

o lOO 200 300 4O0 meter

/^ — — ~isL

PL. 3 Salinity. Summer Cruises

I I Coastal water < 30%'„

I I Intermediate water 30— 32%'o

I I Bank water 32-33%'<,

BB Slope water 33— 35%'„

IB Atlantic water > 35°/,,

PL. 4 Temperature. Spring Cruises.

CZH 5-10° c.

[ZU 0 -5° c.
d] < -0° c.

1

5ect. I-III, C.G.S. "Princess'^
" IV, % "33"
" V-IX, C.G.S. "Acadia"

TV;

^ I

lis/

nr

n

m

i!^

/<>\/£^

V

Scale of depth

o lOO 200 300 4O0 meter

PL. 5 Temperature. Summer Cruises.

^ > 10° c.

CZ] 5-10° c.

lZ! 0 -5° c.

nz\ < 0° c.

PL. 6 Specific Volume. Spring Cruises.

CD 800-1000

^B 600- 800

K3 500- 600

CZ] 400- 500

^B 300- 400

I\^

i" I V

n

m

/#-

Sect. I-III, C.G.S. "Princess"
" IV, ^s "33"
" V-IX, C.G.S. "Acadia"

in

IX,

\m

YR

J

19

VI

^^

\

y..

■x

K

t

o 100 200 300 4O0 meter

PL. 7 Specific Volume. Summer cruises

> 1000
I I 800—1000
■1 600— 800
M| 500— 600
I I 400- 500
IB 300— 400

PI. X

Depth in metres of the Isosteric Surfaces
Spring Cruises

6551— 25i.

PI. XI

Depth in metres of the Isosteric Surfaces
Summer Cruises

0551 — 25 j.

o o O O O

Pi. XIV Calculated velocities. Spring ^915

PI. XV Calculated veioci ties, Summer 1915

CANADIAN FISHERIES EXPEDITION, 1914-15.

Results of the Hydrographical Observations made by

Dr. Johan Hjort in the Canadian Atlantic

Waters during the year 1915

PALL BJERKAN, Bergen, Norway

(With Three Plates and Eleven Figures in the Text.)

G551 — 26

TABLE OF CONTENTS

PAGE.

I. The Expedition 349

II. The Gear and Methods 350

III. The Hydrographical Observations 356

A. Spring Cruises —

Gulf of St. Lawrence 3'57

Xova Scotian and Xewfoundhind Banks 360

Review of the Spring Cruises 362

B. Summer Cruises 364

Gulf of St. Lawrence 364

Nova Scotian and Newfoundland Banks 366

Review of the Summer Cruises and comparison with the results of the

Observations in spring 370

IV. Addendum 374

C. Autumn Cruise 374

Hydrographical Tables 379

FIGURES AND PLATES

PAGE.

Fig. 1. The new Nansen Stopcock Water-bottle, open 351

2. The Water-bottle rerv-ersed and closed 351

3. Richters reversing thermometer 362

4. Knudson's automatic pipette.^ 353

5. A bulb-burette for titration 363

6. Arrangement for chlorine titration 354

7. A Standard water tube 365

8. Map showing the course of the Aiitumn Cruise 374

9. Section along the Nova Scotian and Cape Breton Island coast 375

10. Section, waters of Cabot Strait 376

11. " w-aters off Cape Smokeg, Cabot Strait, etc 377

Plate I. General map of area investigated 404

" II. Sections from the Spring Cruises 404

" III. Sections from the Summer Cruises 404

RESULTS OF THE HYDROGRAPHICAL OBSERVATIONS

MADE BY DR. JOHAN HJORT IN THE CANADIAN

ATLANTIC WATERS DURING THE

YEAR iyi5.

By Pail 1>.jki{KAX, Bergen, Norway.

J 11 the following.' account of the hydrojiTaphical observations made by Dr. Johan
ITjort iu the Canadian Atlantic waters during the sprinji,- and summer of 1915, the
main features of the expedition and the implements used in the work at sea and in
the laboratory are first briefly dealt with, followed by an account on the hydrographical
observations illustrated by sections and maps showing the results of the expedition.

I. THE EXPEDITION.

Oil Dr. Hjort's arrival in Souris, Prince Edward Island, the headquarters chosen
for the expedition, on the first of May the harbour and adjacent waters were filled with
ice as far as the eye could see, and reports from outside showed tliat the pack ice lay
to the north of Prince Edward Island and round the Magdalen Islands. These condi-
tions prevailed during the week from the 2nd to the 8th of May. The ice was supposed
to have been forced southward against Prince Edward Island from the northern areas
of the gulf of St. Lawrence by the prevailing northwesterly winds. Northumberland
strait and the Pictou coast were also barred by ice, and the steamboat communication
between the latter place and Charlottetown, P.E.I. , was interrupted and at times quite
brought to a standstill. The C.G.S. Princess tried twice during the week to force
its way through the ice eastward to Souris in order to take Dr. Hjort for a preliminary
cruise north to the Magdalen islands and adjacent waters. At last she reached
Charlottetown. Dr. Hjort and Professor Willey, of McGill University, went on
board there, and on the 10th of May the Princess started for the cruise. It was decided
that the Princess should run west of Prince Edward Island and try to pierce the ice
up to Magdalen islands. In Northumberland strait, ice-packs were met with every-
where, but the air was pleasant and mild. The Pi^incess got out of the ice west of
Prince Edward Island and headed for Magdalen islands. Station 1 was taken to the
west of Bradelle bank, and heading east the Princess entered small areas of pack-ice.
When well out of the ice, station 2 was taken. Arrived at the west side of the Magdalen
islands, she steamed round the archipelago to Pleasant bay, where the ice had been
driven away by northwesterly winds. Herrings had been observed near the island,
hut the fishing gear had not yet been placed in position owing to the ice.

On account of the severe illness of Commander Wakeham, the expedition was
discontinued on the 13th of May.

• thp middle of May the ice conditions in the gulf of St. Lawrence changed
totally. About the 20th of May the Halifax papers stated that the gulf ice had beec
driven towards Cape Breton island by the northwesterly winds, and had barred the
Cut of Canso. About the 25th of j\ray the rest of the ice was gone, having been
melted or driven out through the (Uit of Canso. The prolonged ice-bound conditions
in the gulf of St. Lawrence this spring were, however, felt on land as well as at sea.
The seasonal developments on Prince Edward Island were, according to the statements
of the inhabitants, put back to the extent of about one and a half months, and at
sea the extraordinary conditions were shown by the retardation of the main fisheries,
especially the herring fishery. Thus the herring fishery round Magdalen islands iu

6551— 26^ 349

350 DEPARTMENT OF THE NATAL SERVICE

the spring was a failure, and the herring the fishermen got arrived comparatively late.
It was thus to be expected that the hydrographical and biological conditions in the
waters of the gulf of St. Lawrence might be somewhat unusual, and the seasonal
development considerably retarded.

After this preliminary cruise the final plans of the expedition were settled.^
For the scientific work the Canadian Government placed two ships at Dr. Hjort's
disposal, the C.G. cruisers Princess and Acadia. The Princess, after the death of
Commander Wakeham, commanded by Captain J. Chalifour, was to undertake two
cruises, one in the spring, and the other in the summer in the gulf of St. Lawrence,
and the Acadia, Commander Anderson, was to undertake two similar cruises in the
Atlantic east of Nova Scotia. The steam drifter No. 3S all the time was to carry on
fishing experiments in the gulf of S^t. Lawrence, this part of the expedition being
conducted by Captain Thor Iversen, who occasionally made hydrographical investiga-
tions, partly embodied in this account. In Souris, Prince Edward Island, a laboratory
had to be improvised for hydrographical and biological work, and here the author took
charge of the working up of the hydrographical material collected on the special
cruises.

From May 29 to June 4 the C.G.S. Acadm made investigations in the Atlantic at
stations 1-36 marked on the map, plate I, while from June 9 to June 1.5 the C.G.S.
Princess made similar observations in the gulf of St. Lawrence at stations 3-26 marked
on the same map.

From July 21 to July 29 the C.G.S. Acadia made observations in the Atlantic at
stations 37-91, while from August 3 to August 12 the C.G.S. Princess made similar
observations in the gulf of St. Lawrence at stations 27-50.

All the time, Dr. Hjort superintended the scientific work at sea with several
collaborators. Water samples and temperatures were taken down to a depth of 400
metres at nearly all the stations, where such depths were found.

In the laboratory at Souris the water samples were tested for salinity, the pre-
liminary calculations made, and the hydrographical material as a whole brought into
such a state as to facilitate its transportation to Norway, where the final elaboration
of the results was to be carried out after the conclusion of the expedition. By work-
ing up the material in this way immediately after each cruise, reliable conclusions
crvild be drawn as to the best course of the next cruise in the same waters.

II. THE GEAE AND METHODS.

In the hydrogrnpliical work on board, a reversing stopcock water-bottle of a new
pattern without frame, invented by Prof. Dr. Nansen (figs. 1 and 2)^ was used. It is
very light and easy to handle, and relatively cheap. The tube is made of tinned brass.
On the outside of the main tube two brass tubes of the ordinary type for thermometers
are fastened. The reversing mechanism is released by a messenger of the usual type
used in oceanographical work.

Six of these water-bottles, brought over from Norway, were used in all the regular
cruises, and always worked very well. During the preliminary cruise up to Magdalen
islands in the first days of May a water-bottle of another pattern was used.

The water samples were kept in ordinary magnesium citrate bottles, which were
found very satisfactory for the purpose.

1 Prior to the actual work of the expedition. Dr. W. Bell Dawson, the head of the Tidal
Survey of Canada, was consulted as to the best routes for the various scientific cruises
embraced in the scheme. Dr. Dawson's opinion as to these was obtained, based upon the inves-
tigations already carried on for many years past in these waters — the special object in view
being the determination of the conditions affecting the migrations of the great schools of
economic fishes in the gulf and adjacent waters.

lAccording to a letter from Dr. Nansen he has new improved the releasing meoUaii'sm of
his water bottle considerably and the messenger now used is not so heavy ns that shown in the
figures.

CANADIAN FISHERIES EXPEDITION, IDl'i-l'j

351

FiK. 1.

—The new Nansen stopcock
waterbotile, open.

Fig. 2.

-The waterbottle reversed and
closed.

352

DEPARTMEyT OF THE yiVAL SERVICE

Ten Eichter reversing thermometers (fig. 3) from Schmidt and Vossberg, cali-
brated to 0-1° Centigrade, were in use, two for each water-bottle. For the surface
temperatures four thermometers (Schmidt and Vossberg), also calibrated to 0-1"'
Centigrade were used. The thermometers were delivered by the international hydro-
graphical laboratory at Copenhagen, and were specially tested in the laboratory. With

Fig. .3. -Richter's re-
versing thermometer.

these thermometers it is possible to read off the temperature to 0-01° Centigrade, but
during the expedition the temperatures, after due correction, were rounded off to the
nearest 0-05 Centigrade, which was found to be sufficiently accurate for those waters.

For sending down and hauling up the apparatus two hand-winches with wire
reels taking about 5U0 metres of wire were in use, the wire having a diameter of about
4 millimetres. A meter wheel of the usual pattern for oceanographical research was
used for determining the depth. By the special lateral arrangement for fastening the
water-bottles to the wire, several water-bottles could be used at the same time.

In the laboratory the salinity of the water samples was determined by means of
chlorine titration, which is the method mostly used in practical work. The amount of
chlorine in sea-water is stated per mille in the same way as the salinity, and defined as
follows : —

By the amount of chlorine we mean the number of grammes of chlorine contained
in 1 kg. of water, supposing the small quantities of bromine and iodine to be
replaced by chlorine. The amount of chlorine is determined in different ways. The

CANADIAN FISHERIES EXPEDITION, lOl'rlo

353

most commonly used is Mohr's titrimetric method, wliich is both rapid and accurate:^
to a certain quantity of the water sample a solution of nitrate of silver is added; the
silver chloride being precipitated as a white flocculent deposit: —

Xa CI + Ag N Oz = Ag CI + Na N Oa.
An indicator is applied to show when all the chlorine has been precipitated, and
the ;i)nount of nitrate of silver added is measured. As an indicator, yellow potassic
chromate (K2 Cr O4) in nearly saturated solution is used. It combines with the

Fig. 4.— Knudsen's
automatic pipette

Fig. 5. — A bulb-burette for
titration.

nitrate of silver (Ag2 Or O4) ; but this reaction does not take place until there is
no chlorine left. When a few drops of the potassic chromate is added to the water-
sample the latter turns yellow, but when all the chlorine has been precipitated by the
addition of nitrate of silver the sample turns red, and the titration is completed.

iThe method is thoroughly described in B. HeUand-Hcitisen, The Ocean waters. International
Revue der gasamten Hydrobiologie und Hydrobidogie und Hydrographie Leipzic, Hydr. Suppl.
Sen. IH, 2 p, 34 af.

354

DEPARTMENT OF THE XAYAL SERTICE

For measuring the water-samples, a Knudsen's automatic pipette (fig. 4.) was
used. The pipette is provided with a stopcock, and after sucking up the water to a
little above the stopcock, the latter is turned; to empty the pipette the stopcock is

Fig. 6. — Arrangement for chlorine titration.

turned further round, so as to be open to the air. The pipette measure 15 or 20
ccm. For the titration a bulb-burette (fig. 5) was used with an upper stopcock (a)
perforated in the same way as in the automatic pipette. In filling and empty-
ing the burette tube by the stopcocks h and c the upper stopcock is used in
quite the same way as in the automatic pipette. From the burette the silver

CAliADIA}i FISHERIES KXrKDiriON, 1911,-lo

355

nitrate solution is emptied into an ordinary smooth tumbler in which the measured
portion of the water-sample has been previously placed. Tlie fluid in the tumbler is
stirred by a glass rod to further the process, and the indicator is added when the chlor-
ine is nearly saturated. When nearing tlie saturation of the chlorine in the water the

Fig. 7. — A s and.irdwatfT nit)e.

silver nitrate solution is added in drops while stirring. The reading of the burette is
made at once while the red colour of the fluid lasts. The essential point in the titra-
tion is that all the different operations in one series of water-samples are done in

356 DEPABTMENT OF THE NAVAL SERVICE

exactly the same way each time, quite automatically, and the nearer one can approach
the ideal of a titration machine, the better are the results.

The arrangement of the titration apparatus with bottle of silver nitrate solu-
tion (a) and burette (h) is shown in fig. 6. For further details about the titration
method, see Helland-Hansen (1. c).

For the titration, standard water was used. The standard water, introduced into
hydrographical investigation by Professor Pettersson is ordinary sea-water with a
salinity of about 35 'Voo. It is examined with the greatest care by different methods
and kept in soldered glass tubes (fig. 7). The standard water is now prepared at the
international hydrographical laboratory at Copenhagen.

The chlorine value of the standard water is known, and can be used to determine
the strength of the silver solution, a certain amount of the solution being found to
correspond to the chlorine value of the standard water. When in this manner the
strength of the silver solution has been determined, it is easy afterwards to calcu-
late the amount of chlorine in a series of water samples. It is assumed that the
silver solution is so made that a titration of standard water gives a reading on the
burette that corresponds neai'ly with the actual chlorine value of the standard water.
To facilitate the operation in this respect the hydrographical laboratory at Copen-
hagen deliver measured quantities of silver nitrate, each to be dissolved in a certain
quantity of distilled water.

The calculation of salinity and density from the chlorine value found and from
the corrected temperature was made by means of Knudsen s hydrographical tables. -

After the conclusion of the expedition the gear and the laboratory outfit wer^
given in charge of the naval store office of H.M.C. dockyard, Halifax, to be used ii<
a supplementary autumn cruise in the Atlantic waters east of Nova Scotia by C.G.S.
Acadia under Commander F. Anderson.

III. THE HYDROGRAPHICAL OBSERVATIONS.

In the hydrographical table the results as to salinity, temperature, and density
are given for each station. The salinity and temperature are dealt with here, while
the density, which is calculated only for use in hydrodynamic studies is given only
in tabular form. As this part of investigation has been taken over by Mr. J. W.
Sandstrom, Stockholm, I refer the reader to his paper for details.

The figures for salinity and temperature in the table have been worked out in
the sections, plates II and III; sections I-IX (plate II) are devoted to the spring
cruises, sections X-XX (plate III) to the summer cruises. The observations shown
m sections I-III and X-XII were made by the C.G.S. Princess, those in section IV
by steam drifter 33, both working in the gulf of St. Lawrence; sections V-IX and
XIII-XX deal with the observations taken on board C.G.S. Acadia, working in the
Atlantic waters east of ISTova Scotia.

The positions of the sections and stations will be found in the general map
(plate I) and are also inserted "in the hydrographical table, together with time and
depth. The Princess stations 1-4 and 27-28, and the 33 stations 54 and 58-59, with
hydrographical data in the table, are not included in any of the sections; each of
the three ships used their special number-series of stations, and I have where neces-
sary used a double designation for the stations, viz., V. 10, XIII, 40, etc.

1- Martin Knudsen, Hydrographical Tables, Copenhagen and London. 1901.
Martin Knudsen, 6t Tabelle, Anhang zu 19 01 herausgegebene.

Hydrographische Tabellen. Publ. de Circ. Copenhagen. 1904.

CANADIAy FISHERIES EXPEDITIOX, 101',-15 357

In working certain main features in the distribution of wati^rs of different salini-
ties in tlie area investigated, I have found it convenient to introduce a special termi-
nology : —

Per cent.

1. Coastal water Salinity, below 30

„ ^ , ,. ^ ^ { 30-water " 30-31

2. Intermediate water... . . ., .. 31-39

( inner " 32-32,5

\ outer " 32,5-33

f 33-water " 33-34

■ ■ \ 34 " " 34-35

Atlantic water " above 35

3. Bank water

4. Slope water.

These varieties, and the limits between them, are of course only approximate,
and the terms are used according to the prevailing conditions. The subdivision is
analogous with that used by Pettersson and Ekman^ in the treatment of the Skager
Rack and Cattegat waters.

Tu the sections the isohalines are represented by continuous lines, those denoting
the main division somewhat thicker than the others. In some cases, especially in
coastal water, additional isohalines, viz., 29 ^/oo, 34-5 ^/oo, and 35-.5 ^oo are drawn in.
The isotherms are represented by dotted lines. Each observation is marked with a
little circle: the figures are not inserted in the sections, but will be found in the
hydrographical table.

Spring Cruises.
GULF OF ST. LAWREXCF (TABLE la)

1. C.G.S. "Princess" OLkx 10 to May 13).

During the preliminary cruise in the gulf of St. Lawrence in the Princess, two
stations were taken: one on the Bradelle bank and the other on the southwestern part
of the Magdalen Islands bank.

Stations 1 and 2.

Salinity. — In the upper strata, down to below 10m., coastal water is found at
station 1, thence to the bottom (69m.) intermediate water with a maximum salinit.v
of 31 -31 '^'00 at 65m. At station 2 the coastal water extends down to below 20m., but
at 40m. (bottom 45m.) the salinity is nearly the same as at station 1, viz., 31-16*'/oo.

Temperatnre.—The melting of the floating ice has cooled down the surface water
to 0° C. at station 1, and 0-35° C. at station 2. At 10m. the temperature is somewhat
higher at both stations, but from 20m. down to the bottom the temperature is below
zero, being at both stations -^1-2° C. at 40m., and -^ 1-4° C. near the bottom at
station 1.

2. C.G-S. "Princess" (June 9 to Jine 15).

The first two stations on this cruise were taken in the shallow water of the
Xorthumberland strait, and are not included in any of the sections.

Stations 3 and Jf.

Salinity. — Coastal water of low salinity, about 2S Vfo, is found from the surface
down to 20m. at both stations, at station 3 ranging from 27-83 Voo to 28-60 "/on. and
at station 4 from 27-65 to 28-12 Voo. The eastern station thus shows the highest
salinity and the greatest difference between the surface and bottom layers.

1 Pettersson ock Ekman : Grunddragen af Skageracks ock Kattegats Hydrografi. Kffl. S.

Vetenskaps Akads. Handlingar, v. 24 no. 11

358 DEPARTMENT OF THE NATAL SERVICE

Temperature. — There is a similar difference in the temperature. The surface
temperature being highest (11-5° C.) at the eastern station, and falling rapidly to
3-6° C. at the bottom (28m.). At station 4 the surface temperature is 8-6° C, and
the bottom temperature 7° C (20m.).

Section I. Stations 5-lJf.

This section runs from off Escuminac point over Anticosti east bank to Natashkwan
bank near the north shore, crossing the Laurentian and Anticostian channels to the
north and south of the former bank. This section represents the first attempt to get
a general view of the changes caused by the in- and out-flovping currents of the St.
Lawrence river.

Salinity. — In the southern part of the section, as far as stations 8 and 9 we find
coastal water down to a depth of 25-15m. deepest at the southernmost station. At the
two northern stations near the north shore the coastal water goes down to 10m. The
rest of the surface is occupied by intermediate water, which on the slopes of the
southern banks goes down to about 80m. at Anticosti bank, nearly touches the bottom at
50m. and keeps to the latter depth over the Anticostian channel. Bank water covers
the Anticosti bank down to a depth of about 110m. on the southern side and 130m. on
the northern side. The 33 Voo isohaline in the main runs at a depth of 120m. over
both channels. No observations were taken deeper than 200m. in any of the channels.
At this depth a salinity of 33.80*^/00 was found in the Laurentian channel near the
northern slopes (station 10), and 33.51 Voo at station 13 in the Anticostian channel.

Temperature. — The surface temperature is highest, up to 10° C, in the south, and
falls towards a minimum (6.45° C), at station 10. Towards the north shore it attains
8° C, at station 14 over ISTatashlvwan bank. At a depth of from 25 to 50m. the temper-
ature falls below zero. The upper 0° isotherm has a very undulating course, at two
1 Idtes extending a little below 50m. This undulating course corresponds to the rapidity
of the decrease of the temperature from the surface downwards. At most stations the
decrease is most rapid at a depth of 20-25m. The lower 0° isotherm lies at a depth of
120-150m. over the Laurentian channel and about 160m. over the Anticostian channel.
The minimum, below -^- 1° C. lies between 50-75m. over the former, and between
60-lOOm. over the latter channel. The highest observed temperature in the depth of
the southern channel is 3.0° C. and in the northern 1.2° C. bxDth at 200m.

Section II. Stations lJf-18.

This section runs from station 14 over C. Wittle bank towards the ISTewfoundland
coast, crossing the Esquimau channel (the deep channel running through Belle Isle
strait).

Salinity .—Coastal water is found from the surface down to 15-20m. at the two first
stations. The surface over the Esquimau channel is occupied by intermediate water,
which here extends down to a depth of about 50m., while over the western banks it is
restricted to the strata between 20-35m. From here we find bank water down to a depth
of lOO'-120m.., and below this we find only slope water with a salinity of 33.69*'/oo near
the bottom (250m.) at the deepest station (station 16). The surface salinity thus falls
0.5 Voo lower over the western channels than over the Esquimau channel, and no coastal
water is found at station 18 near the Newfoundland coast, the surface salinitv being
there 31.25 Voo.

Temperature. — The surface temperature decreases but somewhat unevenly from
west to east from 8° C. at station 14 to 5-95° C. at station 18. The decrease down-
wards is most rapid over the banks, where the 4° isotherm is found at a depth of about
13m., while over the channel it sinks to about 25m. The layer of water having a

CANAIH.W /•7n///;A7/;.S hXI'Hn/TfOX, l-H'i ir, 359

temperature below zero is found from 30m. over the banks, and GOm. over the channel,
down to about 125m., whence the temperature increases slowly to 2-4° C. at a depth
of 250ra.

Section III.. Stations 19-26.

This section runs from St. George bay, Newfoundland, to off Souris, Prince
Edward Island, over the eastern part of the Magdalen Islands bank, crossing the Lau-
reutian channel to the west of Cabot strait.

Salinity. — The coastal water is restricted to the two southernmost stations, extend-
ing down to about 30m. at station 2(). The banks are covered by intermediate water,
which from station 24 occupies the surface with 31-water over the deep channel.
The bank water we find on the slopes towards the channel in a depth of 50-lOOm.
In the middle of the channel at Station 20 it is found at a depth from 70-140m., but
is again stowed up against Newfoundland. The 34 isohaline lies at a depth of about
240m., and at a depth of 400m. we have a salinity of 34-78 Voo.

Temperature. — The temperature of the surface waters down to a depth of 20-30m.
is higher than 4° C, the highest readings being found in the south, where the tempera-
ture is about 7° C. The bottom on the banks is covered by water with temperatures
below zero. The upper 0° isotherm runs between 20 and 40m. over the banks, but
sinks to between 50 and 70m. over the channel. The lower 0° isotherm lies at about
100m. on the slopes of the southern banks, but sinks down to 130-140m. over the
northern part of the channel. The temperature increases again towards the deep
water, and in 400m. we find a temperature of 4-25°C.

The salinity, as well as the temperature, seems to indicate an outflowing current
from the gulf towards the slopes of the southern banks, and an inflowing current in
the middle part of the channel, the changes being mostly restricted to the upper 100m.

3. Steam Drifter "No. 33" (Juxe 25 to June 26).

Section IV. Stations 21-26.

This section was taken by the steam drifter No. 33 from the New Brunswick
coast to Anticosti island in order to show the changes in the sea further up towards
the St. Lawrence river.

Salinity. — The salinity of the surface water increases from south to north from
23-07 at station 21 to 30-85*^/00 at station 24 near the Anticosti coast. At 20m. this
condition is reversed in the middle part of the channel, from 31-01 Voo at station 22
to 30-07 ^'/oo at Station 26. The coastal water thus in the middle of the channel
extends down to about 20m., while in the north the intermediate water is lifted up to
the surface. Bank-water in the main occupies the strata between 50 and 100m., though
somewhat deeper in the middle. The 34 isohaline runs at a depth of about 215m., and
at a depth of 380tn., near the bottom, we have a salinity of 34-72 Voo.

Temperature. — The surface temperature is fairly uniform, from 7-0°-8-9° C,
but in the southern part of the section it falls very rapidly down to 20m., while in the
rest of the section the decrease is greater between 20 and 25m. The layer between
50 and 100m. has a temperature below zero, and the limits of the water of negative
temperature follow very closely the isohalines limiting the bank-water. From 100m.
downwards the temperature increases very slowly to about 4-5° C. at 350-380m.

After this the principal changes seem to be restricted to the upper strata with an
outflowing surface current along the southern coast, causing a reaction current in the
opposite direction at a depth of about 20m., while along the Anticosti coast the current
seems to be inflowing-.

360 DEPARTMENT OF THE NATAL SERVICE

NOVA SCOTIA AND NEWFOUNDLAND BANKS (TABLE 16).

4. C.G.S. "Acadia" (May 29 to June 4).

Section V. Stations 1-16.

This section runs from the Nova Scotian coast off Halifax, over Sable Island bank
towards the Gulf Stream. The section in its seaward half seems to run along the
border region between the Salter and warmer Atlantic water and the cold water from
the north. This is shown by the undulating course of the isohalines as well as by the
successive temperature maxima and minima all along the section.

Salinity. — From the surface down to a depth of about 50m. intermediate water
is found at the first four stations; over the Sable Island bank it appears again very
faintly near the surface. The bank-water Ave find near the coast in a stratum
between 50 and 125m., and over Sable Island bank it is present from the surface down
to 70m .to the west, and 60m. to the east of the bank. Out from the bank the S2t
isohaline has an undulating course between 50 and 80m., rising suddenly between
stations 12 and 13 and reaching the surface between 13 and 14. The slope water occu-
l)ies the rest of the section, with the exception of station 10, where Atlantic water is
found from the surface down to 400m.

The extensive masses of slope-water may be understood when we remember that
this part of the section runs along the southern slopes of the Newfoundland banks.

Tempe'iature. — The surface tem]ierature is comparatively uniform between 4°
and 5-5° C. as far out as station 13, thence the temperature increases to 12-2° C. at
station 16. In the upper stratum between 25 and 30m. the vertical changes in the
temperature are small. At station 1, near land, and at station 12, with its strong
vertical minimum, the decrease is more rapid. The greatest mean fall in the tem-
perature wc lind Leiweeu l!0 and 50m. In depths of 30 to 100m. we have liorizontally
tlie greatest changes of temperature, with maxima and minima in succession from
station to station. The first minimum ^- 0-25° C. we meet with lat stations 3 and 4;
on the western sJopcs of the Sable Island bank the temperature is not much lower
than at the surface, but on the eastern side a minimum of 1-25° C. is found at station
11. The great miniiuum at station 12, where readings down to -f- 1-7° C. were
recorded in the most conspicuous in the section, and has a marked vertical extension.

Below we find a slightly marked maximum with temperature a little higher than
6° C. in depths of 175 - 225m., indicating that we are near to the Gulf Stream. From
station 13 the temperature increases, but unevenly, indicating that cold water masses
are still present to the north. At station 16 the temperature steadily decreases from a
maximum at 75m. down to 400m. The course of the 6° isotherm in depth of 100 -
150, may help to explain the above mentioned maxima at stations 11 and 12.

Section VI. Stations 16-22.

This section runs from station IG towards the Newfoundland coast, with the last
station, station 22, over Green bank.

Salinity. — The salinity of the surface decreases from station 16 towards the bank,
the decrease is most rapid between stations 17a and 18. Over the bank and south to
station 18, bank-water of high salinity occupies the superficial layers down to 50-
60m. The bottom of the bank is covered by slope-water with the 34 isohaline sloping
down from the surface at station 17a to a depth of about 140m. on the slopes of the
biuik. The Atlantic water occupies most of the outer part of the section, and the 35
isohaline has in the upper 70m. a sloping course touching the surface near station 16.

Temperature. — We have also a decrease in the surface temperature towards the
bank, and this decrease is most conspicuous between stations 17a and 18, with a sud-

CAXADIAX riSHEh'lES KXrEDITlOy, IDl'fi: 361

(Icii fall of 4° C. A minimum with temperature below zero lies over Green bank
from about 50m. down to 125m., and a maximum caused by the invasion of Atlantic
water is found, farther out, between 50 niirl lOOni. These two conditions seem to be
the cause of the successive maxima and uiiiiiina in a vertical direction in the middle
part of the section (station 18), the tcmixTaturc rau^iii^' from about 2° to 5° C.

Section VII. Stations 22-2~.12.

This section runs from station 22 on Green bank over the southeastern slopes of
St. Pierre bank out to section V, station 12.

Salinili/. — Frcmi the surface down to a dt'iith of (iO-lOOni. over the banks and
45-S5ni. farther out, bank-water of high salinity is found. The rest of the section is
occupied by slope-water, and the 34 isohaline runs at a depth of about 125-150m.

Temperature. — The surface temneratvire is comparatively uniform throufrhout the
section from about 3.5° to 4.5° C., but the decrease downwards varies greatly at the
different stations, Avhile temperature minima are found at different depths. Over the
banks a layer of water of negative temperature is found from 50m. downi to the bottom
and at station 12 we have the marked minimum noted in section V. These two minima
seem to be connected with each other, but their connection is only indicated in the sec-
tion by the low temperature (1.9° C), at station 27 at a depth of 75m. This connection
might be found between this section and section VI, though nearer to the first. Below
150m. we find at station 12 a tongue of w^ater having a temperature of 5.0° to 6.5° C.,
pressing against the slope, and at station 26 extending above 125m.

The conditions at stations 12 and 27 seem to indicate that rapid changes in salinity
as well as temperature take place.

At station 27 two observations of salinity and temperature were made with about
half an hour's interval (see table lb). The first gave a salinity of 33.88 V^" and a tem-
perature of 4.7° C., the second 34.42 Voo and 7° C. The density varied little, viz.,
1.02684 and 1.02695 and it thus seems that in the short interval, referred to, more
southerly, Salter and warmer water has displaced the northern, colder water of about
the same specific gravity.

We may here review the conditions obtained in this area at the time of the cruise:
From the banks in the north we have a south-flowing cold current with its middle part
somewhat east of section YII. On meeting the strong Atlantic warm current the
colder water is stowed up, and a back-water is formed as indicated at station 12. The
colder water is forced upwards and downwards through the contact, as sho\\ai hy the
vertical extension of the minimum, and is at last deflected in a westerly direction
towards the slopes of the Nova Scotian banks, where we find indications of colder
water in the minima at stations VIII, 28-29 and V 9-10.

Section Till. Stations 27-33.

This section runs from station 27 over Banquereau, Misaine bank, and ('. Brot<in
bank to station 33 off Cape Breton; it crosses the channels between the banks and lies
parallel with the Laurentian channel.

SaUnitii. — From the surface down to a depth of 50m. is a layer of intermediate
water of high salinity. Fi'om 50m. down to 125-150m., bank water covers the bank,
and rises to the surface at station 27. The outer slopes of Banquereau, from a depth
of about 150m., are covered by slope-water, which must be presumed to occupy the
deepest part of the channels between the banks.

Temperature. — The surface temperature is very uniform from 4.0° to 4.75° C.
The banks up to 25-40m. are covered by water of a temperature lower than 2° C, with
a minimvim of 0.0° C. at Banquereau and about ^- 0.3° C. at Misaine bank. Only the

362 DEPARTMENT OF THE NAVAL SERVICE

shallowest parts of the banks are thus covered by water of negative temperature.
Towards the deeper water the temperature increases very slowly in the channels
between the banks, and comparatively rapidly on the outside of Banquereau, where a
temperature above 5° C. is reached at a depth of 150m.

Section IX. Stations 33-36.

The last section on this cruise runs from station 33, off Cape Breton, to station 36,
near the coast of Newfoundland, crossing the Laurentian channel at the outer part of
Cabot strait.

Salinity. — From the surface north of station 34, down to a depth of 60m. near the
southern slopes, is a layer of intermediate water stowed up against the south shore.
The bank water in the northern part of the section occupies the surface and reache*
down to 100-160m. The 33 isohaline has an undulating course, rising as a wave up
to 100m. at station 35, and sinking down towards the slopes on both sides of the
channel. The rest of the section down to the bottom is occupied by slope water with a
salinity of 34.66 Voo near the bottom (400m.) . The 34 isohaline runs at a depth of
225-250m., displaying a wave similar to that of the 33 isohaline.

Temperature. — As in the foregoing sections the surface temperature is very uni-
form 4-4.5° 0. At a depth of 30-125m. on the southern slopes, and of 60-115m.
on the northern slopes, we find water layers with temperature below zero. These two
minima are separated by somewhat higher temperature in the middle of the channel at
station 35, and their influence is shown by the course of most of the isotherms in the
section, the upper 2° and 4° isotherms running somewhat deeper at station 36, and
the lower 2° and 4° isotherms forming waves upwards at the same station. Near the
bottom (400tn.) we find a temperature of about 4° C., almost identical with the surface
temperature.

This section confirms the impression mentioned under section III, that the gulf-
water forms an outflowing current along the north shore of Cape Breton island. This
current seems to be more superficial and its water fresher, salinity from 30-5 ''/oo to
about 32 ^/oo, than the water of the inflowing current in the northern part of the
channel, which seems to be strongest in depth of 50-lOOm. The outflowing water
is thus intermediate water and inner-bank water, while the inflowing water is outer-
bank water having a salinity characteristic of the Newfoundland banks. The posi-
tions of the two temperature minima in the section seem to confirm this idea about the
origin of the superficial layers in the Cabot strait.

EEVIEW OF THE SPRING CRUISES.

After this description of the sections made during the cruises in the spring it may
be of interest to review the hydrographical conditions in the area investigated. In
doing so I may conveniently refer to the section maps constructed by Mr. Sandstrom
and given in his report (The Hydrodynamics of the Canadian Atlantic Waters, plates
II and IV).

Salinity (Sandstrom, Plate II),

Coastal Water {helow 30 Voo). — At the surface, water of this salinity is found in
the inner, and especially in the southern part of the gulf, round Prince Edward
Island, and in the north out towards the middle of the Esquimau channel. In the south
we find the coastal water down to a depth of about 25m. Water of a salinity below 30*^/00
must also presumably occur almost everywhere nearer to the coast, and especially in
bays with outlets of fresh water. Thus it is certain that the surface water of the Nova
Scotian banks oft' the Gut of Canso to some extent consists of coastal water, though the
spring cruises did not include this area.

CANADIAN FISHERIES EXPEDITION, 191.'rl5 363

Intermediate Water (30-32 "/oo) is found at the surface in the middle part of the
gulf of St. Lawrence, over the inner and northern parts of the Nova Scotian banks, in
the latter area out towards the slopes, and over the southern and larger part of the
Laurentian channel. The 31-water forms the mass of this surface water and the 30-
water is mostly present only as a rim round the Salter water. Only in the Nova
Scotian bank area, off the Gut of Canso, we find the 30-water at the surface projecting
fls a broad tongue out towards the Banquereau. At a depth of 25m. the intermediate
water occupies the gulf, with the exception of the area close up to Prince Edward
Island, and the Nova Scotian bank area, south to Sable island, and out to the slopes in
the north, near to the Laurentian channel. At a depth of 50m. intermediate water is
found in the larger part of the gulf, excepting the northern middle part, and on the
inner part of the Nova Scotian banks. At a depth of 100m. only slight indications of
intermediate water are found close to the southern slopes of the Laurentian channel off
Gaspe.

Bank u'ater (32-33 V^o). At the surface, water of this salinity seems to occupy
the large Newfoundland banks to a little out from the slopes towards the Atlantic
depths and the Laurentian channel. Off the latter it occupies a wider area of the surface
out from the slopes, but farther south and west it is again restricted to a rim over the
slopes. At a depth of 25m. the intermediate water occupies about the same area as at
the surface, but at 50m. we find it in the northern middle part of the gulf with a very
narrow tongue projecting up the Laurentian channel close to Anticosti island. The
Newfoundland bank area at the latter depth, too, is covered by bank-water, but off the
Laurentian channel the Atlantic influence is felt as a broad tongue of salter water
projecting north and west towards the channel. At a depth of 100m. the bank-water
occupies the Nova Scotian and Newfoundland banks, with the exception of part of the
areas near the southern slopes, where salter water is found. Salter water is also
found as a tongue projecting north and west along the northern slopes of the Laurentian
channel through Cabot strait, with a bend to the south of the tip of the tongue towards
the Magdalen Island east bank. The rest of the gulf at this depth is occupied by
bank-water.

Slope water (33-35 Voo). At the surface down to a depth of 25m. we find the slope
water only as a rim off the slopes towards the Atlantic ocean, somewhat broader in the
west, narrower in the east off the Great bank, where the Atlantic water sets on. At
50m. we find the slope water as the above-named broad tongue towards the Laurentian
channel. At 75m. the rim of slope water lies close up to the slopes and the above-
named tongue is broader. At 100m. the tongue projets up the Laurentian channel,
through Cabot strait, and touches the ^fagdalen Island east bank, as mentioned above.

Atlantic water (above 35 Vooj. — Only at stations V, VI, 16 do we find water of
this high salinity at the surface and down to 400m. At station VI, 17 we find it from
50m. down to 400m., and at a depth of 100m. it reaches as far towards the Great bank
as station VI, 17a, but only as a wave confined to this depth.

6. Temperature ( Sandstrom Plate IV).

The surface temperature in the gulf of St. Lawrence during the firy-t part of .Tune
mostly falls between 5° and 10° C. The highest surface temperature, 11-5° C, is
found at station 3, and the lowest, 4-2° C, at station 21. It is of interest to note
that the higher surface temperatures are found in the southern part of the gulf near
the coasts, and the lower over the channels leading out to the Atlantic ocean. The
surface temperature thus found over the Laurentian and Esquimau channels seems to
be the common surface temperature over a great part of the Nova Scotian and New-
foundland bank area, where the surface temperature seems to be fairly uniform^

6551—27

364 DEPARTMENT OF THE XATAL SERVICE

between 3-5° and 5-5° C. A higher surface temperature is found further out at
stations V 14-16 and at VI 17-l7a, where temperature from 8-1° to 12.:3''0. are met
with. This is due to the influence of the Atlantic water. A lower temperature is
found at the northern stations off the Newfoundland bank, down to ?-2°C. nt station
VI 21, where the influence of the Arctic current is strongest. In the gulf the tem-
perature decreases from the surface down to the intermediate minimum layer with a
temperature below zero. This decrease is more rapid nearer the coasts, and especially
so in the southern part of the gulf, near Magdalen hay, where the highest surface
temperature was found. The intermediate minimum layer of negative temperature is
most prominent in the middle part of the gulf, round Anticosti east bank, and espe-
cially over the Anticostian channel, where it forms a layer 120 to 150m. in depth.
Over the Newfoundland banks we meet with a similar intermediate layer of cold water
with temperature down to -^1-4° C, lying somewhat deeper. Through the northern
half of Cabot strait this stratum seems to be connected with other areas of interme-
diate cold water. It seems probable that this cold intermediate layer in the gulf has its
principal source in inflowing currents from the cold water-layers south and east of
Newfoundland. This inflowing current is indicated in section IX from Cabot strait,
but similar conditions might have been found to obtain in Belle Isle strait, had this
area been covered by the investigation. These currents are presumably reaction cur-
rents, acting against the outflowing currents in the upper strata, as found in the
southern part of the Cabot strait. The melting of the winter ice in the gulf may be
another source, but this is not nearly suflieient to account for the mighty proportions
of these intermediate, cold water-layers in the gulf. The outflowing cold water from
the gulf, indicated by the soutliern minimum found in section IX, Cabot strait, forms
another area of intermediate cold water-layers over the inner part of the Nova Scotian
banks (section VIII). The extension of this area is merely indicated by the investi-
gations, but we find that part of it extends as far south as station V 3.

As stated on p. 360, the cold-water layers of the Newfoundland banks have another
outlet in a southwesterly direction towards station V 12, where they are deflected in a
westerly direction towards the Nova Scotian banks by contact with the Atlantic water.
This concentrated, strong current might be connected with the inner, intermediate
minimum area of the banks through several of the deep channels between the banks;
for instance, the Gully. At least we find indications of it along the slopes far south
and west (see p. 369).

Towards the deep water the temperature again increases, but slowly, out from the
Atlantic slopes through a water-layer with higher temperature (over 5° C.) in depths
from 100 to 250m. The latter is connected with the warmer layers farther out. At a
depth of 400m. the temperature is about 4° C. near the slopes, and it increases towards
the Atlantic ocean to 9-30° C. (station V, VI, 16) at the same depth.

Summer Cruises.
GULF OF ST. LAWRENCE (TABLE Ic).
1. C. G. S. " Princess " (August 3 to August 12).

Siatio)is 27 and 28.

The two first stations on this cruise were taken in the shallow water of Northum-
berland strait, very near to the corresponding stations 3 and 4 of the spring cruise.

Salinity. — At both stations we find coastal water from the surface down to the
bottom. While, however, at the western station (station 28) the salinity is fairly con-
stant down to the bottom (20m) we find at the eastern station a difference of about 1
7oo

CAXADIAy FIHUERIE^ EXPElJfTIOX, 19J>,15 365

Temperature. — The same difference is shown by the temperature, which at station
28 is fairly uniform, 18-5°-l7 0° C, from the surface down to 20m., while at station
27 we find 16-4°-16-5" C from the surface down to 10m., but 8-4° at a depth of 20m.
This difference indicates a surplus of fresh water at the western station and the
presence of a strong: current round the western point of Prince Edward Island, which
mixes the Avater-masses and hri ufis relative fresh water down to the bottom layers.

tSection A\, iitations 29-W.

This section corresponds to section I of the spring cruises. The resemblance
between the two sections is obvious, but in the upper .^Om. we find marked differences,
mostly due to the presence of large quantities of fresher water during the summer
cruise.

Salinity. — Coastal water is during the summer found at the surface out to the
slopes towards the Laurentian channel and towards deep water it is in the southern
part found down to 50m., but this layer of fresher water is rapidly flattened out super-
ficially towards the slopes. From station 34 the salinity of the surface water keeps
about 30 Voo with small maxima and minima, to 29-49 Voo near the north shore
(station 40). In the latter northern half of the section the intermediate water occupies
the superficial layer down to about 50m. In the south it is forced down to about 70m.,
by the coastal water and over the Anticostian channel, bank water is forced up to 35-
40m. The bank water thus occupies the deeper parts of the southern banks the Anti-
costi east bank and the slopes towards the channels down to 100-125m. The rest of the
channels towards the deeper water is occupied by slope water, with from 34-65 to 34-72
Voo at a depth of 350m, in the Laurentian channel and .34-29 Voo in 275m. in the
Anticostian channel.

Temperature. — The temperature corresponds with the salinity. The temperature
at the surface is much higher than in the spring, and falls from 17 0° C. at the
southern stations through several minima and maxima to 11-15° C. at station 40.
The decrease towards deep water is verj- variable relatively more rapid in the northern
half than over the southern banks, where we find a temperature of 5-65° at 100m. at
station 30. The upper 0° isotherm nearly falls in with the isohaline for 32 Voo, and
'thus lies about 30m. deeper in the south than in the north. The lower 0° isotherm
has a slanting course over the channels, from about 105m. towards the southern slopes
to about 170m. towards the northern slopes in the Laurentian channel, and from 130 to
lS5m. over the Anticostian channel. The waterlayer of negative temperature is thus
in the summer also more prominent near the Anticosti bank and the northern chan
nel than farther south. The minimum is, however, less marked in summer than in
spring. The area having a temperature below -^ 1° C. is comparatively small and the
lowest temperature is -;- 1-15° C. as compared w-ith -^ 1-35° C. found during the
spring. In the depth of the chamiels we find temi)erature 4-45° C. at 350m. over the
Laurentian channel, and 3-95° at 275m. over the Anticostian channel.

Sf.ction XI, Stations J/O-U.

This section corresponds to section II of the s])ring cruise, and thus runs over
C. Wittle bank and crosses the Esquimau channel.

Salinity. — Coastal water is only found at a thin layer at the surface at Natash-
kwan bank towards the shore, thus having a much smaller extension than in the spring.
The intermediate water occupies most of the section from the surface down to 50m.
Over Natashkwan bank and towards the shore, however, it only reaches down to 30-40m.,
and near t« the Newfoundland coast down to 40m. The banlv water occupies the rest
of the water-layers over the banks and channels from 5f)m. down to 125-140m. The

6551—27*

366 DEPARTME'NT OF THE NATAL SERYIUE

bottom of the channels is covered by slope water with a salinity of 34-27 Voo at 250m.
over the Esquiman channel.

Temperature. — -The surface temperature is comparatively unifoi-m from 11-65° C.
at station 40 to 13-45° C. at station 44. The temperature decreases more rapidly over
the Natashkwan bank, 8° C. being found at a depth of 8m., while farther out it is found
in depth of 18-26m. The layer of negative temperature is more prominent in this part
of the gulf in the summer than in the spring, in contrast to the conditions found in
the western section. It reaches from o5-60m. down to 150-l70m. The temperature
near the bottom (250m.) over the Esquimau channel is 3-75° C.

Section XII, Stations 50-J!f5.

This section corresponds to section III of the spring cruises, though farther east,
cutting through the northwestern point of C. Breton island.

Salinity. — Coastal water is found from tbe surface down to 2O-30m. in the
southern part of the section, deeper in the south. In the southern half of the Cabot
strait, coastal water is found as a layer at the surface 5m. thick. Intermediate water
occupies the bottom layers of the southern banks with the exception of station 49,
where bank water is found at a depth of 70m. Over the Laurentian channel, inter-
mediate water is fomid down to 50-60m. in the larger part of the section, but only
down to about 30m. near the Newfoundland coast. Bank water is found at the deeper
part of the southern banks and over the Laurentian channel from about 100m. at the
southern slopes to 150-170m. near the Newfomidland coast. The rest of the channel
towards deep water is filled with slope water with a salinity of 34-70 Voo in 400m.

Temperature. — The surface temperature is highest in the southern part of the
section, with temperature above 16° C. From station 48, however, we find a succes-
sive decrease of the temperature, to 12.45° C. near NewfoundlandL The decrease of
temperature towards deep water is very sudden from 25m. at the three southernmost
stations, while towards the north we find a more uniform decrease between 25 and
100m. The layer with negative temperature is at the southern bank found at a depth
of about 35-65m. Near to the southern slopes we find cold water in the Cabot strait,
too, but no layer with negative temperature. At stations 47 and 46 we find traces of
such a layer with temperature about 0° C. at a depth of 10O-125m. This position
of the cold water-layer explains the more uniform decrease of the temperature, towards
deep water at the northern stations. From this cold water-layer we find an increase of
temperature towards deep water, but in such a way as to indicate that colder water-
masses are stowed up towards the northern slopes than towards the south. At a depth
of 400m. we find temperature of about 4° C. The conditions as regards salinity as
well as temperature seem to indicate that the two opposing currents: the outflowing
one along the southern shore and the inflowing one along the northern shore, found
during the spring, still prevail.

NOVA SCOTIA AND NEWFOUNDLAND BANKS (TABLE Id).
2. C.G.S. "Acadia" (July 21 to 20).

Section XlII, Stations S7-U-

The section runs from Shelburne, Nova Scotia, in a southeasterly direction to
station 44, off the slopes towards deep water, and crosses La Have bank at about the
middle.

Salinity. — Intermediate water of high salinity (31-water) is found near the
coast from the surface down to about 80m. The 32 Voo isohaline slopes steeply

CAAADIAN FISHERIES EXPEDITIOX, lOl'rlo 367

and reaches the surface a little out from station 40. Over the bank the water-
layers thus have a sloping direction, and the salinity incroi-.-jS very rai»idly bet>Acen
stations 40 and 41. The layer of bank water is of comparatively small extent. 0\er
the bank it extends from 50 to 100m., and covers the bottom at the odcre of the bank.
From there the layer ascends as a narrow rim towards the surface. The slope water
covers the slopes of the bank between 100 and 160m., and thence ascends to the surface
where it forms a layer down to 20-25m., making a conspicuous bend down to 50m. at
station 43. The rest of the section out from the slopes and below 25-50m., is occupied
by Atlantic water, with a salinity in places as high as 36-99 ^/w (station 33, Y5m.).
Layers of very high salinity (above 35-50 Voo descend as a tongue down to about
170m. at station 43.

Temperature. — Near the coast at stations 37 and 3^ we find a minimum with
temperatures below 2° C. in depths of 60-80m. This minimum shows its influence
vertically as well as horizontally, and the isotherms run almost concentrically to the
minimum in the bank part of the section. The surface temperature increases from
a minimum of 9° C. at station 37 to 19-7° C. at station 44, with a very rapid increase
between stations 40 and 41. Between these two stations all the isotherms in question
trend vertically, to become horizontal again: thq 16° isotherm at a depth of 45m.,
the 12° isotherm at about 165m. and the 10" isotherm at a depth of 250m. All these
isotherms display a conspicuous bend downwards at station 43, where layers of salt
and warm Atlantic water seem to have sunk down (see above). The influence of the
Gulf Stream is very conspicuous in this section, but the bank proves a strong barrier
against the warmer water-masses, limiting their influence to the slopes facing the
ocean.

Section XIV, Statioijs Ifi-lfJt.

The section runs from station 49, near the coast of Nova Scotia, northeast of ■
Halifax, to station 44 of the foregoing section, and crosses the Sambro baiik.

Salinity. — From the coast and almost out to station 46, just over the seaward
slopes of the bank, intermediate water is found from the surface down to 25-30m.
The surface about station 46 is occupied by bank water, which from there descends
below the intermediate water as a comparatively thin layer 20m. in thickness, increas-
ing in bulk towards the coast, where it covers the slopes in depths of 3O-150m. The
rest of the surface is covered by slope water down to about 20m. at the outermost
station (station 44), and to about 250m. on the slopes of the bank. The bank is
covered by a layer of slope water about 80m. in thicknessi. From about 20m. down-
wards we find Atlantic water at station 44. The Atlantic water is found as far
inwards as the slopes of the bank in depth of 250-350m. As in the foregoing section
the influence of the Gulf Stream is very marked. The edge of the bank lies deeper,
and the slope water has flowed over it, forcing the layer of bank water to a more-
horizontal position than shown in that section, though the shape of the layer is
similar, a horn of plenty with the opening downwards and eoastwards.

Temperature. — Near the coast we find the same minimum (below 2''C.) as in sec-
tion XIII, though more marked, from 65-135m. This minimum shows its influence
horizontally and vertically, especially downwards. The surface temperature increases
from the coast seawards, with a very marked jump from 13-35° to 17-0°C. between
stationsi 47 and 46, which corresponds to the changes in the salinity near the same place.
In the outer part of the section the 15° isotherm has a markedly sloping course, cutting
the surface between station 47 and 46 and running at a depth of about 90m. at station
44. The bulk of the section, near the surface and round the bank, is occupied by water
having a temperature between 8° -15° C, with somewhat colder water at a depth "f
300 •360m. out from the slopes.

368 DEPART3IENT OF THE NATAL SERVICE

Section XV, Stations 1^9-56.

The section runs from station 49 of the foregoing section to station 56 off the
slopes towards the ocean, and crosses S^ahle Island bank at its southwestern part.

Salinity. — The surface layers lie still more horizontally than in section XIV.
Intermediate water is found near the coast from the surface down to about 45m., and
the 32 Voo isohaline cuts the surface near station 52, and almost follows this, display-
ing small minima in the salinity as far seawards as station 56.

Bank water is more pronounced than in any of the foregoing sections of this cruise,
forming a continuous layer all over the section in a horizontal direction. Near the
slopes from the coast the layer is about 80 to 100m. in depth, but is thinned out over
the inner channel and over the deeper water. Slope water covers the bank and the
slopes on each side with 34-water from 125m. downwards on the slopes facing the ocean.
Atlantic water is found from 45m. down to 400m. at station 56, and at depths of 150-
250m. it forces its way as near to the slopes as midway between stations 54 and 55.

Temperature. — In this section we find two minima, with temperatures below 2° C,
one placed as in section XIV close up to the coast, the other over the seaward edge of
the banlc. The position of these two minima determines the character of the tempera-
ture conditions in the water-masses occupying the bank and the channel on the inside.
The water from the surface down to 20-25m. has a temperature above 10° C. The sur-
face temperature increases from the coast seawards, with a sudden jump between
stations 54 .and 55 from 13-9° to 16-35° C. The 10° isotherm trends vertically from a
depth of 20-257n. at station 56, where we find a temperature above 10°C. between 20 and
275m., proceeding towards the slopes of the bank at a depth of 100 to 150m. The
slopes below 125m. are covered by water having a temperature between 5 and 10° C.

Section XVI, Stations 65-56.

The section runs fi-om station 65 off Canso, to station 56 of the foregoing section,
and crosses the Middle bank and Sable Island bank somewhat west of the island.

Salinity. — Off Canso we find traces of coastal water near the surface. Inter-
mediate water goes down to 75-50m. between the coast and Middle bank, but is restricted
to the tipper 25m. over Sable Island bank. The banks are covered by bank water down
to 60-80m. in the outer part, but in the inner channel the bank water is found to at
least 150ni. As far out as over the edge of the bank we find a layer of bank water from
the surface down to about 40m., with a minimum of intermediate water at the surface
at station 56. The deeper parts of the channels and the slopes towards the ocean are
covered by slope water. Atlantic water is only found at station 56, from 45m. down
to 400m.

Temperature. — The minimum with temperatures below 2° C. is restricted to the
inner channel, while the banks are covered by water having a temperature between 2
and 5* 0. The 10° isotherm runs at a depth of 8 to 25m. and in the inner half of the
section the temperature is between 11-5° and 13-5° C, with a rapid increase between
stations 59 and 57 from 11-55° to 17-5° C. From station 56 the 10° isotherm trends
Vertically, and at this station we find temperatures above 10° between 25 and 290m.
The seaward slopes of Sable Island bank are covered by water having a temperature
between 5° and 8° C, with a minimum of 3-5° C. at a depth of lOOm.

The influence of the Gulf Stream is less pronounced in the two last sections than
in the others, and the outer edge of Sable Island bank is influenced by temperature
minima displaying the presence of water of northern origin.

CAXADIAX FISHERIEi< KXrEDlTlOy, 191',-1-J 369

Sect'on XVII, Staiions Go-7o.

The section runs from station 05 off Canso in an easterlj- direction to station 75
in deep water, and crosses the Canso bank and Banquereau.

Saliniti/. — The traces of coastal water at the surface at station 5G are mentioned
labove. Intermediate water is fomid at the surface as far seawards as station 71.
Near the coast it goes down to 75m., and the 32 'y^') isohaline runs in a slanting
direction, cutting the surface at station 75. Bank water occupies the bank and the
.channels, and from the outer edge of the Banquereau there is a layer of water about
'30m. thick, thinning out towards the surface until it is restricted to the upper 10m.
at station 75. Slope water occupies the sea^\ard slopes of the Banquereau, and
Atlantic water is found at stations 72 to 75 in depths of 13O-220m. to 55-325m. at the
last-montioned station.

Temperature. — There are two minima with temperatures below 2° C, one occupy-
ing the banks and the channels and the other situated at a depth of 30-80m. at stations
72 and 73. The position of the latter minimum is almost identical with that of the
'conspicuous minimum at station V 12 of the spring cruise. The conditions seem to
'be similar to those found in the spring. The course of the current of cold water seems
to be the sartie, and the temperature over the banks to the west shows that the current
of cold water is later on deflected to the west, as was found in the spring. The surface
temperature has a minimum over the edge of Banquereau, and from there it increases
^ery slowly towards the coast, and more rapidly seawards. The 8° isotherm runs
horizontally, though somewhat undulating, at a depth of about 25m., from the coast
•to station 73, where it trends vertically, and at station 75 runs at a depth of 325m.

Section XYIII, Stations 75-70.

The section runs in a northerly direction from station 75 of the foregoing section
to station 79, towards the slopes of the Xewfoundland banks.

Salinity. — Off the mouth of the Laurentian channel we find intermediate water
at station 76 from the surface down to a depth of 35m. It covers the surface to a
little north of station 77. Bank water is found at the surface in the northern and
southern parts of the section, at station 76 it goes down to 75m. The layer of bank
water is very limited in extent, only 10 to 30m. This seems to be due to the influence
of the superficial intermediate water from within, and the slope water from without,
which latter forces its way up the Laurentian channel at a considerable depth. The
deeper parts of the section are almost exclusively occupied by slope water, and the •
Atlantic water is limited to the southernmost station (station 75) at a depth of 60
to 325m,

Temperature. — The surface temperature decreases from the south tow-ards the
banks, from 16° C. to about 13° C. At station 76 we find a minimum with tempera-
tures below 2° C. This minimum is most probably the same as that found in section
XVII, stations 72 and 73. The course of the 8° isotherm is similar to that in section
XVIT, running horizontally at a depth of 30-40m. in tlie northern part of the section,
trending vertically at station 76. The minimum lies in tlie deeper part of the bank
water, and the slope water has mostly a temperature between -1° and 6° C.

Section XIX, Stations 79-S3.

The section runs from station 70 of the foregoing section in a northwesterly
direction to station 83, crossing St. Pierre bank.

370 DEPARTMENT OF THE NAYAL SERVICE

Salinity. — Only traces of intermediate water are found near the surface at stations
SO and 83, the rest of the surface being occupied by bank water, which covers the
bank down to about 75ni. at the seaward slopes, and occupies the channel down to
150m. The deeper parts of the channel and the rest of the sections below 50-75m.
are occupied by slope water.

Temperature. — The surface temperature lies between 11° and 13° C, and the 8"
isotherm runs horizontally at a depth of about 25m. The slopes of the bank on both
sides are covered by water with a temperature below 0° C, at places as low as ^-
1-45° C. and the temperature on the bank lies between 0° and 2-5° C.

Section XX, Stations 89-83.

The section runs from station 89 off C'anso to station 83 of the foregoing section,
and crosses Misaine bank, the Laurentian channel and St. Pierre bank.

Salinity.— ^The surface down to 10 to 30m. is mostly occupied by intermediate
water, for only over St. Pierre bank is bank water found at the surface. Over the
southern bank intermediate water goes down to about 60m. Bank water covers the
is^hallowest parts of the banks on each side, and fills the channel north of St. Pierre
bank ^almost to the bottom. Over the Laurentian channel the bank water keeps to a
depth of 10 to 60m., and the rest of the channel is occupied by slope water with a
salinity as low as 34-78 ^/oo at a depth of 400m.

Temperature. — The surface temperature is comparatively uniform with a maxi-
mum of 14-65° over the Laurentian channel. The 5° isotherm rims at a depth of 40ra.
over St. Pierre bank, and rises to about 25m. over Misaine bank, with a peculiar bend
down to 60m. near the outer edge of the former bank. At a depth of 75m. we find a
minimum, with temperatures below 0°, at stations 87 and 86, which in some way
seems to be in connection with the water-masses, having a temperature below zero,
which occupy the channel between St. Pierre and Newfoundland. At least the layers
between 50 and 125m. have a comparatively low temperature, below 3° C. The water-
masses occupying the deeper parts of the Laurentian channel have a very unifonn
temperature between 4 and 5° C. with a slightly marked maximum above 5° C. at a
depth of 150 to 225m. close up to the northern, slopes.

REVIEW OF THE SUMMER CRUISES AND COMPARISON WITH THE
RESULTS OF THE OBSERVATIONS IN THE SPRING.

As with the spring cruises, it may be of interest to review the hydrographical
conditions found in the summer, and then compare the results from both seasons.
As before. I refer the reader to the section maps in Mr. Sandstrom's publication
(Sandstrom, plates III and V).

a. Salinity (Sandstroji, plate hi.)

Coastal water (helow 30 'YooA — As in the spring, water of this salinity is found
.especially in the southern part of the gulf, round Prince Edward Island. The most
conspicuous difference' is that coastal water in the summer is found to a considerable
deptli (45m.) northwest of the island, while in the other parts of the gulf, where
coastal water was found in the spring, it seems to be more thinned out and limited to
the surface. Thus in the north along section XI, we only find it near the coast,
while in the spring we found it occupying the surface as far out as C. Wittle
bank. On the other hand, we find it in areas, where it could not be traced in the
spring, as in the southern part of Cabot strait, stations XII 46 and 47, and off
Canso, thus indicating that C. P>reton island is surrounded by a broad rim of coastal

CANADIAN FISHEJilES EXPHDITION, 19I',-lo 371

water. Traces of these conditions might have been found in the spring as suggested
by me as regards the area outside the Gut of Canso, but the investigations did
not cover this area. The observations are, however, sufficient to show that the
outflow of relatively fresh gulf water from the superficial layers is more pronoun. •ed
in the summer than in the spring. This circumstance might explain the thinning out
of the snperficial coastal layer o\er the greater part of the gulf, though the coastal
water is found far more extensively in the southwestern part during the summer.

Intermediate water (30-32 Voo^'. — At the surface the intermediate water is found
in the northeastern part of the gulf, the northern half of Cabot strait, as a broad rim
south of Newfoundland, and occupying the Nova Scotian bank area with the Laureutian
channel. In two places the superficial layers of intermediate water force their way out
over the Atlantic depth, viz., off the Laurentian channel and east of Shelbume, N.S.
At a depth of 25m., intermediate water occupies the gulf with the exception of the
larger southern bank area, in the Atlantic it is found over the Xova Scotian bank area,
with the exception of the larger part of the Sable Island bank, and further it is found
as a broad rim south of Newfoundland, but not over the outer part of the Laurentian
channel. The two offshoots of intermediate water in the direction of the Atlantic depths,
noted at the surface, are marked at this depth as well. At a depth of 50m., intermediate
water occupies the southern and western parts of the gulf, the southern
and larger part of Cabot strait, and a rim east of Nova Scotia, with
broader portions in the north and south, marking off the two offshoots of
intermediate water in the more superficial layers, mentioned above. At a depth of 75m.
intermediate water is only found in the gulf over the deeper parts of the southern banks
between Gaspe and Magdalen islands. When we compare the extension of the inter-
mediate water during the summer with that found in the spring, it is noteworthy that
water of this low salinity is found farther out at the surface during the summer, thus
showing the influence of the outflow of fresher water from the estuaries near the coast.
The northern offshoot very sharply marks off the water-masses from the gulf of St.
Lawrence, and the southern one is most probably a result of the outflowing fresher
water from the Bay of Fundy.

BanJc water (32-33 '^/oo). — At the surface, water of this salinity is only found on
the shallower parts of the Newfoundland banks, and on the sloi>es of Sable Island bank
and La Have bank. Between these three areas it is forced seawards by the above-
mentioned offshoots of intermediate water. At a depth of 25m. it occupies the area
covering the Newfoundland banks and their slopes, the outer part of the Laurentian
channel, the slopes of the Nova Scotian banks and the larger part of Sable Island bank.
At 50m., bank water occupies the northeastern part of the gulf, the northern part of
Cabot strait, the Newfoundland and Nova Scotian bank area, with the exception of
Canso bank and part of Misaine bank. In the Laurentian channel, salter water at this
depth forces its way along the northern slopes, while on the other hand the bank water
sets on off the mouth of the channel and penetrates a distance out from the slopes.
At Y5-100m., bank water occupies the middle part of the gulf, the landward slopes of
the Newfoundland banks, the slopes and the channels of the inner Nova Scotian bank
area, and the Laurentian channel out to a line off the western point of St. Pierre bank.
At 200m. no trace of bank water is found.

Comparing the spring and summer conditions as regards the distribution of bank
water we find that superficially it is forced seawards in the summer by the outflowing
fresher water. This influence is felt down to at least 25m. Deeper down the salter
water sets on and forces the bank water back, especially in the Laurentian channel,
•where at a depth of 75-lOOm., it is found only as far out as off the western point of
St. Pierre bank. At a depth of lOOm. we found in the spring an offshoot of salter water
along the northern slopes of the channel as far in as Cabot strait; this we do not find
during' the summer, for it has been forced away by the bank water, which farther out

372 DEPARTMENT OF THE NATAL SERVICE

in the channel is carried towards the surface, and pushes its way through the sovithern
part of the channel out over the Atlantic slopes down to a depth of 50in.

Slope water (83-35 ^/m). — At the surface down to 25ni. slope water is only found
over the Atlantic depths, close up to the slopes off La Have bank and Great bank,
farther out in the larger part of the area between them, though somewhat nearer the
slopes south of Sable Island bank. At 50m. the seaward slopes of the Newfoundland
and Nova Scotian banks are covered by slope water. Along the southern slopes of St.
Pierre bank a tongue of slope water is found, while the southern part of the channel
IS occupied by fresher water. At 75 and lOOm. the seaward slopes and the deeper
parts of the Newfoundland banks, as well as the outer Nova Scotian banks, are
occupied by slope water, and in the Laurentian channel it penetrates as far as off the
the western point of St. Pierre bank. At 200m. slope water occupies the submarine
channels, the Atlantic slopes and the deeper pits of the Nova Scotian bank area.

Comparing the spring and summer conditions as regards the slope water we find
the difference most marked in the Laurentian channel, where in the summer it is
stoved up by a wall of bank water at a line off the western point of St. Pierre bank,
at a depth of 75-lOOm., while in the spring it is confined to the mouth of the channel,
and only sends a long and narrow offshoot along the northern slopes of the channel as
far inward as Cabot strait.

Atlantic water (above 35 V'joj. — Water of this high salinity is not foinid at the
surface in any of the sections, but on the slopes of La Have bank and Sambro bank we
find it close up to the slopes at a depth of 150-175m. and downwards. Farther out at
sea we find it as close to the surface as 25-50m. south of La Have, Sambro, and Sable
Island banks, and off the Laurentian channel it seems to have penetrated farther in
towards the channel at a depth of 100 to 200m. than in the spring.

h. Temperature (Sandstrnui Plate V).

The surface temperature is naturally much higher in the summer
than in the spring; this is mostly due to the influence of the fresher
water from the coast, which as we have seen forces its way far out to sea, but
also to the force of the Gulf Stream, which especially at some places sets on stronger
than in the spring. This circumstance is shown most plainly when we draw in the 16°
isotherm. In the gulf it runs from Gaspe to Cape Breton ; south of this line the surface
temperature is higher than 16° C. The highest surface temperature in the gulf is
found in Northumberland strait (station 28), viz., 18.5° C, and the lowest close up to
the north shore (station X 40), viz., 11.65° C. In the main the surface temperature
decreases from south to north, and from the Newfoundland coast towards the north
shore. In the Atlantic ocean the 16° isotherm runs along the slopes of the bank; only
off the mouth of the Laurentian channel the isotherm bends seawards. Out from the
slopes we have higher temperatures, the highest temperature being observed at station
XIII 44 (19.7° C). The lowest surface temperature observed during the summer
cruise is found at station XIII 37, near the coast off Shelburne, viz., 9.7° C. The
surface temperature in the Atlantic generally increases from the coast towards the
ocean. The lower readings being found very often over the edge of the banks, especially
in the northern part of the area.

Downwards the temperature decreases towards a layer of water of minimum
temperature. In the inner part of the gulf of St. Lawrence, the 10° isotherm mostly
runs at a depth of about 10m., but in the outer part at a depth of about 20m. The
layers of water of negative temperature we mostly find from a depth of 50- 80m. down-
wards. The lower 0° isotherm runs deeper in the northern part of the gulf, and the
layers of water of Jiegative temperature are thus more extended in the north especially
over the Esquimau channel, where the lower 0° isotherm runs at a depth of about 160m.

CANADIAN FISHERIES EXrEDJTION, VJl'i-lo 373

Over this channel these cold-water layers are more extended during the summer than
in the spring, a circumstance which seems to confirm the idea that there is a constant
inflow of colder water through the deeper parts of Belle Isle strait. In Cahot strait
we find traces of water layers of negative temperature, a slight minimum occurring
in the middle of the strait at a depth of 95-125m., where the salinity is between 32-5
and 3)3 "iMi (outer bank water). In the Atlantic ocean, the 10° isotherm rnns mostly
horizontally at a depth of 15 to 30m. In the two southernmost sections it very suddenly
trends vertically over the edge of the banks, farther north it trends vertically at a
distance off the slopes, especially off the mouth of the Laurentian channel. It becomes
horizontal again at a depth of 25O-300m. The deeper parts of these warm water-
masses (below 20m.) belong- to the Gulf Stream, as shown by the salinity, while tli(^
upper strata seem to be of more continental origin. Off the Laurentian channel the
influence of the water from the gulf of St. Lawrence at the surface seems to lie
unquestionable, at least as far out as station XVII 74, and the offshoot of relatively
fresh water at the surface south of Sable Island bank indicates that similar conditions
prevail in this area too. Water having a temperature between 0 and 5i° C. occupies the
deeper parts of the Laurentian channel and the channels between the Nova Scotian
banks, as was the case in the spring. In the spring \ve found layers of wat6r of
negative temperature at least over the'northei'n Xova Scotian banks; in the summer
in the Atlantic part of the area investigated these layers are limited to the channels
and slopes of the Xewfoundland banks, with slight minima situated over deep water
as found at stations XVIII 76 and XX 86 and 87.

The conditions reviewed above seem to indicate an increase in the influence of
the Gulf Stream and of the currents of continental origin, while the influence of the
Labrador current seems to have decreased from spring to summer. The water-masses
of continental origin have enlarged their area of distribution in a more horizontal
direction, occupying the superficial strata, while the Gulf Stream has forced its way
close tip to the slopes with w-ater-masses of immense vertical extension. The Labrador
(Arctic) current displays its influence in nearly the same areas as in the snring, but
the higher temperatures and salinities show that its influence has diminished. The
northern branch of the current turns round cape Ray and runs westward along the
Xewfoundland coast; the southern branch runs more to the south at right angles to
the direction of the Laurentian channel. This latter branch is deflected towards the
Xova Scotian banks through contact with water-masses of Atlantic origin. As shown
above (p. 369) these conditions are found during the summer as well as in the spring.
The water-masses especially characteristic of this current are mostly found ;it a dcntli
of 80 to 250m. during the summer, and from about 30m. downwards in the spring!.
Though the influence of the Labrador current off the Newfoundland banks seems to
have decreased in the summer, the contrary seems to be the case with the branch of
the current entering the gulf of St. Lawrence through Belle Isle strait, as shown by the
masses of water of negative temperature over the Esquimau channel. I cannot find
any other explanation of this fact than aii increased inflow of cold water from the
north, and at the same time I take it as an indication that the principal :source of the
(layers of excessively cold water in the gulf of St. Lawrence is to be found in the
inflowing currents of Arctic water entering the gulf through Belle Isle strait and
Cabot strait.

Before concluding this paper I must express my sincere thanks to Di*. Johan
Iljort for his kindness in giving me the opportunity of working out the results of the
expedition as regards the hydrographical observations, and also for his suggestions
as to the best way of attacking the work, and for his valuable help in the details.
My best thanks are also due to Mr. James Chumley, Glasgow, who has revised my
manuscript in a masterly manner, and to Messrs. Einar Lea and Thv. Easmussen,
Bergen, for valuable help by preparing the figures.

374

DEPARTMENT OF THE NATAL 8ERTICE

rV. ADDENDUM.

SUPPLEMENTASY CKUISE IN C.G.S. "ACADIA" CONDUCTED BY COM-
MANDER F. ANDERSON IN THE AUTUMN OF 1915.

As stated on p. 356, a supplementary cruise in the autumn of 1915 had been
planned in order to follow up some of the most important features in the hydro-
graphical conditions of the waters investigated- This cruise took place in C.G.S.
Acadia from November 14 to November 22, and the hydrographical material collected
has been sent to Norway for further elaboration in connection with that from the
spring and summer cruises. As, however, tlie latter material had been worked up,
the sketches drawn, and the manuscript almost ready for printing, it was found most
convenient to finish this part according to the original plans, and to work up the
results of the autumn cruise as an addendum.

The cruise was laid from Halifax, N.S., out to station V 4 of the spring cruise,
and from there along the coast of Nova Scotia and C. Breton island north to the New-
foundland coast and back again to C. Breton island, twice crossing Cabot strait. The
most interesting part of the cruise is the two cross-sections of the Laurentian channel,
the one almost identical with section IX of the spring cruise, the other more westerly.

i'ig. 8. — Map showing the course of the Autumn cruise.

Fig. 8 shows the course of the cruise and the most interesting features of the bottom
configuration.

AUTUMN CRUISE (Table le).

Station 92.

The position of this station is the same as station Y 3 of the spring cruise. As it
cannot very well be included in any of the sections it is taken apart.

Salinity. — The salinity of the surface water is not as high as in the spring, 30-40
against 30-92 Voo. The 30-water reaches down to 40m., against lOm. in the spring.
Down to 60m. the water is Salter in the spring than in the autumn, but from there
down to the bottom the salinity is almost identical in both seasons.

Temperature. — From the surface down to about 40m. we find that the tenmerature
is very uniform, between 8-2° and 8-4° C. From this depth the temperature decreases
evenly to 1-9° C. at 110m. During the spring we found a uniform temperature (a

CAyADIAy FISHERIES EXPEDITION, ldl.',-13

375

little above 4° C.) down to 20m, but from there a sudden fall to temperatures below
zero Between a depth of ^0-75m. and an increase farther downwards to 2-4°C. at llOra.

Section XXI, Stations 93-98. (Fig. 9).

The section runs from station 93, identical with station V 4 of the spring cniise
to station 98 off Cape Breton, and crosses Canso bank.

Salinity.'^. — Intermediate water is found from the surface down to 50m. in the
southern part of the section ; north of Canso bank it goes down to about 75m. In the

om

Sect. XXI

95 9^

100

200

Fig. 9 — Salinity and temperature along the coast from off Halifax to off Cape Breton.

south the 31-water predominates, in the north the 30-water. Off Halifax the bank
water is only present as a thin layer in a depth of about 50-60m., over the banks it
occupies the strata from 50m. down to the bottom and north of the banks from about
75m. to 125m. The deeper parts between the banks are filled with slope water, mostly
33-water, but south of the banks we find 34-water near the bottom (150-185ni.). The
lower salinity of the water in the northern part of the section is obviously due to the
outflow through the Gut of Canso, from which a deep submarine channel leads towards-
station 97.

Temperature. — The temperatures confirm the facts found by the salinity, with the
exception of those found from the surface down to 50m. at station 94 (see the footnote,
below). The 31-water in the south has a temperature higher than 8° C. and the 30-
water in the north mostly has a temperature between 5° and 8° C. From about 50m.
in the south, and 75m. in the north, the temperature decreases rapidly, in the south
towards a minimum with temperatures about 4° C. at 75-lOOm. with higher temper-
atures, up to 7-4° C. in a depth of 150m., while over the banks and over the northern
channel it is continuously decreasing towards the bottom. Xear the bottom of the
banks we find temperatures of about 1-9° C, and near the bottom in the channel north
of the same we find a temperature of 0-8° C.

1 N.B. — As regards the salinities from the upper 50m. at station 94 (table le), I find that
some errors in the labelling of the water samples must have taken place. The salinities found
in the table fall quite inversely to what might be expected, but comparing the salinities with
the corresponding temperatures the latter display a very uniform character corresponding to
the temperature at the same depths at the neighbouring stations 92, 93, and 95. The isohalines
In section XXI are therefore drawn according to a revision of the salinities made by the author,
while the observed (?) salinities might be found in the table.

376

DEPARTMEyT OF THE NATAL .SERVICE

Section XXII, Stations 99-102 (Fig. 10).

The course of the section and the position of the stations are almost identical
with those of section IX of the spring cruise.

om.

^fOO

Fig. 10. — Salinity and temperature across Cabot strait, eastern section.

Salinih/. — Coastal water is found near the surface at station 99, but the salinity
of the surface water increases rapidly to 32-24Voo at station 100. Down to a depth of
about 90m. we have, however, a wed'ge of intermediate water, mostly 30-water, dis-
playing the outflow of the water-masses from the gulf. Bank water occupies the rest
of the section down to 100-125m., consisting from the surface down to 60-T5ni., mostly
of inner bank water, while higher salinities are not as commonly distributed. From
100-125m. down to 400m. we find slope water, with the 34 Voo isohaline at a depth of
30O-35Om., forming a wave to a little above 300m. at station 101. The salinity in
400m. runs from 34-70 to 34-80Voo.

Temperature. — The temperature at station 99 from the surface to the bottom
(60m.) is very uniform, falling between 7-35° and 7-5° C. and the wedge of inter-
mediate water near the coast seems to have a temperature higher than 5° C. The
inner bank water from the surface down to 50-75m. in the northern part of the section
mostly has a temperature between 4-5° and 5-0° O., while up to the Newfoundland
coast we find temperatures a little below 4° C. in 25 and 50 metres depth. Tlie tem-
perature decreases very suddenly when descending into the outer bank water, where
we find temperatures between 0-2 and 1-8° C. From 75-lOOm. to about 160m. we find

CANADIAN FISHERIES EXi'LlilTlON, 10t',-l.j

377

temperatures between 0-0° and 10° C, but farther downwards the tempera. uro
increases to about 4° C in 300 and 400m. The layers of water of temperatures below
zero, found especially in the spring, are not found during the autumn, but the inter-
mediate temperature minimum at a depth of 100 to 160m. indicates that idiMiiical
water-layers are still found there, but their temperature is increased during the
summer.

Section XXIII, Stations 107-102 (Fig. 11).

The section runs from station 107 off cape Smoke on C. Breton island to station 102
of the foregoing section, and crosses the Cabot strait like section XXII, but more
westerly.

dm

Sect XXIII

107 106

400

Fig. 11. — Salinity and temperature across Cabot strait, western section.

Salinity. — Coastal water is not found by the observations but intermediate water
of low salinitv- (30-water) is found at station 107 from the surface do^\ai to at least
60m., thus indicating that coastal water is found at the surface nearer to the coast.
This suggestion is confirmed by the pbserv^ations at station 99 of the foregoing section.
The intermediate water covers the surface seawards to about station 105, and vertically
extends down to about 100m. near the coast. As in the foregoing section the 30-water
is predominant and the 31-water only forms a rim close up to the 32 Voo isohaline.
This feature seems to indicate that we have to do with water of different origin, the
fresher outflowing water near the southern coast and the Salter water in the northern
part of the section. From the surface down to 100-l25m. this consists of hank water

378 DEPARTMENT OF THE NAYAL SERVICE

with the 32-5 Voo isohaline running- at a depth of 50-75ni. The deeper part of the
section down to 400m. is occupied by slope water with a salinity between 34-70 and
34 • 80 Voo at 400m. The conditions so far confirm those found in section XXII, only
at the slopes of the bank found between stations 107 and 106 they seem to be somewhat
different. As will be seen in the table, the position of the water-masses along the slopes
of this bank seems to be quite disturbed. The bottom of the bank and the slopes down
to about 25m. from its edge are covered by 33-water, while deeper down, at about 140
to 180m. we find 31-water. The temperatures, as seen below, correspond with this
inverse position of the water-masses. I can only explain the fact as follows: A wedge
of Salter water is, by the configuration of the bottom or other agencies, forced upwards
and inwards, being at the same time undermined by a similar wedge of fresher water
running in the opposite direction. This position of the water-masses is not stable,
but as, however, the salinity and the temperature are in conformity we are forced to
acknowledg'e the fact.

Temperature.— The temperature of the intermediate water-masses seems to be
somewhat lower than in section XXII . This is, however, only apparent as station
XXIII 107 lies more seaward than station XXII 99, which is also shown by the higher
salinity at the former station. Nearer up to the coast we should most possibly find
about the same temperatui-e up to 7°-8° C, as in that section, the position of the
isotherms is almost the same in both sections, and the only exception is the cooling
down of the neighbouring water-masses over the bank, where the wedge of Salter and
colder water from the deeper parts has ascended.

Compared with conditions in the spring and summer it seems as if the inflowi:::,'
current in the northern part of Cabot strait, whose activity we found had diminished
somewhat in the summer time, has again increased and forced the more continental
water-masses up to the southern shore of the strait. The salinity of this inflowing
current, the western branch of the Labrador current, is however somewhat lower, and
the temperature, at least deeper down, somewhat higher than in the spring. This is
obviously due to the mixing of the Labrador water over the banks with the warmer
and fresher continental water-masses, which during the svimmer predominated at the
surface far seawards over the banks.

CANADIAN FISHERIES KXrEDlTlON, /.'>//-/,»

379

Table la. — Salinity, Temperature and Density of the water in the Gulf of
St. Lawrence during the spring of 1915.

C. G. S. "PRINCESS".

Station, time,
position and depth.

S

a

Q

Salinity

6.

S

Density

Station, time,
position and depth.

£

a.

Q

Salinity

i

Si
Eh

Density

Stat.l. May 11

9 a.m.
N. 47° 30' 00"
W. 63° 23' 00"

69 m.

0
10
20
30
40
50
65

Voo

29-79

29-88

30-38

30-59

31-17

31-25

31-31

00

1-5
^ 0-2
~ 0-7
^ 1-2
-H 1-4
H- 1-4

1- 02393
1- 02393
1-02442
1-02459
1-02507
1-02514
1 02520

Sect. I, 6. June 10

12.20 p.m.
N. 47° 30'
W. 64° 08'

61 m.

0
10
20
2c
30
40
6C

Voo
27-71
29-83
30-46

31 13
31 14
31-54

9-6

4-4

3-1

1-8

-=-0-75

H-0-8

-^115

1 021.36
1- 02367
1- 02428

1- 02503
1-02504
1 02538

Stat. 2. May 11

3.20— 4. 30 p.m.
N. 47° 27' 00"
W. 62° 10' 30"

45 m.

0
10
20
30

40

29-70
29-73
29-92
30-31
31-16

0-35
0-8
^0-3
^O-l.'^

H-1-2

1-02385
1-02.385
1- 02405
1-02435
1 02506

Sect. I, 7. June 10

3.40— 4..30 p.m.
N. 47° 50"
W. 63° 37'

76 m.

C
10
20
21
5C
75

27-35
27-86

31 12
31-68

9-5
5-3
51
2-0
0-4
^0-95

1-02110
1-02202

1-02467

Stat. 3. June 9

11 a.m. — 12 noon.
X.46°02'
W. 6.3° 25'

0
IC
20
22
25

27-83
28-44
28 -02
28 -6C

11-5

4-8
3-15
3-2
3-6

1-02115
1-02254
1-02274
1-02280

1-02499
1- 02549

25 m.

Sect. I, 8. June 10
8.15— 10.00 p.m.
N. 48° 11'
W. 6r04'

92 m.

Oj 29-04
10 "xi . R'-

91
7-75
71
1-85
0-2
-=-11

-r-0-6

-=-0-6
-=-0-5

1- 02247
1 02312

Stat. 4. June 9.

5.10 p.m.
N..46°28'
W. 64° 21'

21 m.

0

5

10

20

27-65
27-73
27-87
28-12

8-6
8-4
8-1
7-0

1-02146
1 02155
1 02170
1-02204

15
20
40
50
60
75
90

30-82
31-23

31-81

32-30

1- 02466
1 02508

Sect. I, 5. June 10

8.50— 9..35 p.m.
N. 47° 13'
W. 64° 35'

31 m.

G
10
15
20
30

27-46
27-82

29-11
30-32

101
8-6
5-8
4-35
2-4

1-02109
1 02169

1-02310
1-02422

1- 02558
1-02597

6551—28

380

DEPARTMENT OF THE NAYAL SERVICE

Table la. — Salinity, Temperature and Density of the water in the Gulf of
St. Lawrence during the spring of 1915 — Continued.

C. G. ,S. " PRINCESS.'

station, time,
position and depth.

s

Q

Salinity

d

d

c
o
H

Density

Station, time,
position and depth.

s

a
c

P

Salinity

d

d

£

H

Density

Sect. I, 9. June 11

12.15— 1.00 a.m.

N. 48° 27'
W. 62° 37'

160—300 m.

0
10
2£
40
50
75
100
125
150
200

Voo
31 00

31-46

32-25

32-84

33-53

8-05
5-9
2-5
0-7
H-M6
-^1-2
-hO-35
0-4
1-25
30

1-02415
1-02512

1-02595
1-02640

1-02688

Sect. I, 13. June 11

4.00 p.m.

N. 49° 45'
W. 61° 15'

ca. 200 m.

0
10
26
40
50
75
100
125
150
200

»/oo
28-44

31-18

31-98
32-54
32-63
33-02
3311
33-51

6-9

31

0-85

-hO-55

-hO-6

^0-9

-rl-05

H-0-6
H-0-25
1-2

1-02230

10250a

1-0257L
1-0261&
1-02626
1-02655
1-02661
1-02686

Sect. I, 10. June 11

7.00 a.m.

• N.48°53'
W. 61° 50'

150—250 m.

C

2?

50

75

100

150

200

30-86
31-66
31-92
32-48
32-86
33 -.30
33-80

6-45
3-1
0-8
H-M
H-0-35
0-05
2-25

1- 02426
1-02524
1-02561
1 02615
1-02641
1-02675
1-02701

Sect. I & II, 14.

June 11
7.00 p.m.
N. .50° 07'
W. 61° 09'

40 m.

0
10
20

25
35

26-15
29-78
31-50

31-95

8-1
3-5
0-9
10
H-0-15

1-02044
1-02370
1-02527

1-02568

Sect. II, 15. June 12

9.00— 10.00 a.m.
X. 49° 45'
W. 60° 08'

85 m.

0
10
20
30
40
60
80

28-94
28-96
30-51

32 10
32-43
32-90

5-75

5-4

4-3

0-7

^0-75

-Hl-3

H-0-85

1- 02282
1-02289
1-0242L

1-02582
1-02611
1-02646

Sect. I, 11. June 11

9.30 a.m.
N. 49° 02'
W. 61° 32'

51 m.

C

10
20
25
30
40
50

31-10
31-09
31-48
31-85

31-88
32-07

6-75

6-2

5-4

1-55

1-15

M5

0-5

1- 02441

1-02448
1-02488
1-02550

1-02556
1 02576

Sect. II, 16. June 12

1.15 p.m.
X. 49° 33'
W. .59°31'

260 m.

0

25

50

60

75

85

100

150

200

250

31-50
31-61
.32-02

32-66

32-94
.33-33
33-34
33-89

6-2

3-9

11

-^0•7

-f-0-7

H-0-7

-=-0-5

0-4

01

2-4

1-02480

Sect. I, 12. June 11

12.30— 1.30 p.m.
N. 49° 27'
W. 61° 20'

140 m.

0
10
26
40
50
60
75
100
125

31-07
31-47
31-75

31-96

32-54
32-83
32-92

7-55
4-45
2-35
0-3
^0-15
-=-1-3
^1-35
-^0-8
^0-45

1-02427
1-02496
1-02537

1-02569

1-02619
1-02641
1-02647

1-02512
1-02567

1-02627

1-02648
1-02676
1-02678
1- 02707

CANADIAN FISHERIES UPTimTION, lOtrl-)

381

Table la. — Salinity, Temperature and Density of the water in the Gulf of
St. Lawrence during the spring of 1915 — Continued.

C. G. S. " PRINCESS."

Station, timo,

c

d

Station, time.

i

d

■z.

Salinity

d

E

o

Density

JS

Salinity

d

Density

position and depth.

a.

o

position and depth.

1

s

Q

H

Q

H

Voo

°

Voo

°

Sect. II, 17. .Tune 12

0

31-55

4-9

1- 02497

Sect. 111,21.

Juno 13

0

31-73

4-2

1 02519

4.30 p.m.

25

31-69

40

1-02518

9.45 a.m.

25

31-72

4-0

1- 02520

N. 49° 22'

N. 47° .52'

W. 58° 56'

35

3-5

W. 60° 04'

50

32-12

2-45

1- 02565

130 m.

50

31-87

0-4

1-02559

ca. 500 m.

60

1-2

60

H-0-95

7r

32-36

-0-1

1-02600

•

75

32-43

-1-1

1-02610

85

-0-2

100

32-66

-=-0-7

1-02627

100

32-66

-0-4

1-02625

125

33 04

0-2

1-02654

200
300

33-89
34-41

2-4
4-1

1-02717

1- 027.32

Sect. II, 18. June 12

0

31-35

5-95

1-02470

400

34-78

4-25

1-02760

7.30 p.m.

20

4-2

N. 49° 16'
W. 58° 37'

30

31-79

0-7

1-02550

Sect. Ill, 22.

10

31-45

4-3

1-02496

64 m.

40

32-16

00

1 02584

June 13

1.30 p.m.

20

31 -.54

3-4

1-02512

50

32-26

^0-3

1 02593

N.47°33'

W. 60° 39'

30

31-89

H-0-3

1-02563

Sect. Ill, 19.

0

31-61

5-35

1-02498

55 m.

40

31-89

-0-4

1-02564

June 13

2.45 a.m.

10

31-62

4-4

1-02508

50

31-9.^

-0-5

1-02569

N. 48° 20'
W. 59° 13'

20

31-03

4-4

1-02509

Sect. Ill, 23.

0

. 31-42

82 m.

30

31-92

1-9

1-02553

June 13

4.00 p.m.

20

31 -SS

4-45

1-02.506

40

1-1

N. 47° ,37'

W. 60° 31'

40

32-04

2-4

1-025.59

50

32 10

0-8

1- 02575

ra. 100 m.

45

32-16

0-0

1- 02.584

60

32-45

0-1

1-02608

5C

-0-8

70

0-0

5.'

32-21

--0-8

1 02.591

80

32-63

H-0-1

1- 02622

60

32-41

-hO-5

1- 02606

Sect. Ill, 20.

25

31-57

4-4

1-02505

80

32-60

^0-4

1-02621

June 13

6.00 a.m.

50

31-61

2-6

1-02524

100

33-07

0-4

1-02655

N. 48° 06'

W. 59° 40'
250-^00 m.

60

75

^0-2
H-0-8

3211

1- 02583

Sect. Ill, 24.

0

.30-31

5-9

1 02389

June 1.^

85

-e-0-9

7.30— 7.55 a.m.
N. 47° 12'

10

30-34

5-9

1-02391

100

32-52

H-0-8

1 02616

W. 61° 20'

15

5-5

125

32-86

^0-25

1 02641

40 m.

2f

30-64

4-1

1-02434

150

33 12

0-3

1 02660

35

31-21

2-4J

1 02493

200

33-77

1-95

1-02700

6551— 28A

382

DEPARTMENT OF THE XAVAL SERVICE

Table la. — Salinity, Temperature and Density of the water in the Gulf of
St. Lawrence during the spring of 1915 — Continued.

C. G. S. "PRINCESS.

Station, time,
position and depth.

D.

Q

Salinity

d

d

Density

Station, time,
position and depth.

a.

c

Q

Salinity

d

d
£

Density

Voo

°

Voo

°

Sect. Ill, 25.

June 15
11.00 a.m.-12.00 noon
N. 46° 45'
W. 61° 27'

0
10
15

29-46
29-50

7-2
6-9
5-5

1-02306
1-02313

Sect. Ill, 26.

June 15
3.00-^.00 p.m.
N. 46° 20'
W. 62° 04'

0
10
15

28-94
29-00

70
6-4
5-3

1-02268
1- 02280

63 m.

18

3-2

40 m.

20

29-40

3-3

1-02342

20

30-68

--0-15

1-02465

25

29-64

2-0

1-02372

25

-0-3

35

30-67

-r-0-5

1-02466

30

31-27

^1-1

1-02515

40

31-33

H-1-1

1-02521

60

31-41

-^1-5

1-02529

STEAM DRIFTER "-33".

Sect. IV, 21.

June 25
7.20 a.m.
N. 48° 51'
W. 64° 10'

0
10
24

28-67
30-35
31-28

7-2

3-65

1-55

1-02244
1-02415
1-02506

Sect. IV, 23.

June 25
1.00 p.m.
N.49°03'
W. 63° 58'

0
10

20

28-59
28-93
30-78

8-1
8-0
3-4

1-02226
1-022.54
1-02451

27 m.

355 m.

30
40. .

31-31

2-15

1-3

0-35

1-02504

50

31-97

•

1-02567,

Sect IV '>2

0
10
20

28-49
29-42
31-01

7-8
5-55

2-8

1.09999

60..

H-0-2
H-0-8
-T-0-3

June 25
9.40 a.m.

N. 48° 54'
W. 64° 07'

02322
02474

75
100

32-51
32-84

1-02615
1-02640

195 m.

30

31-50

1-6

02523

150

33-48

1-3

1-02682

40

50

75

100

125

150

31-99
32-37
33-06
33-49
33-75

0-0
-^0-8
-v-0-45
0-35
1-4
2-35

250
350

34-22
34-62

3-7
4-55

1-02721

02573
02602
02654
02682
02696

1-02745

Sect. IV, 24.

June 26
5.25 a.m.

N. 49° 23'
W. 63° 38'

0
15
24

30-83
31-10
31-27

70
6-0
5-2

1-02416
1-02450
1-02473

190

33-87

2-6

02703

45 m.

42

32-32

01

1-02597

CANADIAy FISHERIES FJPEDf.TION, 191 yi3

383

Table la. — Salinit}-, Temperature and Den.sity of the water in the Gulf of
St. Lawrence during the spring of 1915 — Concluded.

8TE.\M DRIFTER ".33."

Station, time,
position and depth.

E

a.

c

Q

Salinity

6

6.
£

o

Density

Station, time,
position and depth.

E

Q.

Q

Salinity

6

d

a

Den-sity

Voo

°

Voo

o

Sect. IV, 25.

June 26
6.20 a.m.
N. 49° 18' 30"
W. 63° 42' 00"

0
10
20

29-66
29-68
30 08

8-25
805
7-4

1-02308
1-02312
1- 02352

Sect. IV, 26.

June 26
9.35 a.m.
N.49° 11' 30'
W. 63° 50' 00"

0
10
20

28-83
29-05
30 07

8-9
7-8
5-55

1 02223
1-02267
1- 02.373

271 m.

30
40

31-38

1-9
0-35

1 02511

389 m.

30
40

31-59

1-75
0-15

1 02529

50

31-92

-r-0-2

1-02565

50

32-38

H-0-8

1-02604

65

-hO-4

75

32-66

-^0•7

1-02627

75

32-48

-=-0-55

1-02612

100

32-92

-hO-15

1 02646

85

--0-4

150

33-37

1-0

1-02676

100

32-97

^0-2

1 02650

200

33-91

2-75

1-02714

150

33-38

1-05

1-02677

250

34-27

3-85

1-02725

269

34-48

415

1-02738

380

34-72

4-5

1-027.53

384

DEPARTMENT OF THE NAVAL SERVICE

Table 16. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the spring of 1915.

C. G. S. "ACADIA".

Station, time,
position and depth.

Q

Salinity

d
a

Hi

Density

Station, time,
position and depth.

a.

0)

Q

Salinity

O
d

H

Density

Sect. V, 1. May 29

9— 10 a.m.
N. 44° 35' 00"
W. 63° 32' 00"

25 m.

10
20

»/oo

30-73

31-35

3-4
2-0

1-02447
1-02507

Sect. V, 5. May 30

1—2.30 a.m.
N. 43° £6' 00"
W. 61° 32' 00"

73 m.

0
10
25
50
70

Voo

32-36

32-43

32-68

32-79

33-08

5-2
51
5-2
40
3*85

1- 02559
1 02566
1-02584
1-02606

Sect. V, 2. May 29

11.05 a.m.-12. 05 p.m.

N. 44° 29' 00"
W. 63° 22' 00"

60 m.

0
10
20
30
40
55

31-00
30-91
.30-94
31-15
31-44
31-74

4 71^

1- 02456
1-02456
1-02460
1-02490
1- 02520
1 02545

1 02630

3
3

1
0

9
9

1
2
95

Sect. V, 6. May .30

5.30— 6.30 a.m.
N. 43° 47' 00"
W. 60° 52' 00"

45 m.

0
10
20
30
40

32-06
32-06
32-05
32 05
.32-15

4-35

4-3

4-2

4-0

3-6

1- 02544
1-02544
1-02544
1-02546
1-02556

Sect. V, 3. May 29

2.30— i.30 p.m.
N. 44° 22' 30"
W. 62° 55' 00"

146 m.

0
10
20
30
40
50
60
75
90
110

.30-92
30-93
31-C6
31-65
31-93
32-09
32-14
32-29
32 -.54
32-82

4
4
4
1
0
H-0
H-0
0
0
2

45

25

15

9

0

25

1

0

45

4

1-024.53
1- 024.55
1- 02467
1-02534
1 02566
1- 02579
1-02.582
1-02594
1-02612
1-02622

Sect. V, 7. May 30

10.15— 11.15 a.m.
N. 4.3° 35' 30"
W. 60° 13' 30"

109 m.

0
10
25
50
75
100

31-90

32-05
33-01
33-22
33-80

4-0

3-9

3-8

2-05

2-6

4-9

1- 02535

1 02549
1-02639
1-02639
1-02683

Sect. V, 8. May 30

12.50 p.m.
N. 43° .50' 30"
W. 60° 04' 30"

51 m.

0
10
20
30
40
50

31-94
31-94
31-98
32-07
32-08
32-14

5-4
5-3
•4-2
3-4
3-4
2-85

1-02523
1-02524
1-02539
1-02554
1-02555
1-02563

Sect. V, 4. May 29

7.30 p.m.
N. 44° 07' 14"
W. 62° 11' 36"

173 m.

0

10

25

40

50

60

75

100

120

160

31-48
31-49
31-56
31-76
31-93
32-33

33-14
33-66
34-29

4
4
4
2

0

1
1
3
5
6

4

85

2

3

85

1

95

0

0

7

1-02497
1- 02497
1-02506
1-025.39
1-02561
1-02592

1-02643
1-02663
1-02692

Sect. V, 9. May 30

5^ — 6 p.m.
N. 43° 44' 00"
W. 59° 24' 00"

106 m.

0
25
40
50
60
75
100

32-19
32-82
33 03

33-09
33-42

3-8
3-3
1-3
1-25

1-7
1-9

2-75

1-02563
1- 02630
1-02647

1-02647
1-02668

CANADIAN FISHERIES EXPEDITION, 1914-15

385

Table 16. — Salinity, Temperature and Density of the water on the Nova Sootian
and Newfoundland banks during the spring of 1915 — Continued.

C. G. S. "ACADIA."

Station, time,
position and depth.

o.

a

Salinity

d

Density

Station, time,
position and depth.

a

a.

Q

Salinity

6

d

£

Density

Sect. V, 10. May 30

0

o/oo
32-48

4-4

1-02577

Sect. V, \2—Con.

150

»/oo
33

79

3

1

1-02694

7.15 p.m.
N. 43° 41' 30"
W. .59° 02 '00"

740 m.

25
50

32-61
3''-74

4-25

9.9

1 02589
1 02616

175
200

34

42

6
6

3
6

1-02707

60

32-83

2-0

1-02626

300

34

49

5

2

1 02727

75
90

32-86
33-58

0-8
3-1

1-02636
1-02677

400

34

45

3

7

1- 02740

Sect. V, 13. May 31

0

32

19

4

1

1-025.56

100
150

33-69
34-40

3-5

5-85

1- 02632
1-02712

4.45—9.45 a.m.
N. 4.3° 27' 35"
W. 27° 18' 25"

25
50

• 32
33

89
56

4
4

65
0

1- 02607
1- 02667

200

51-

over .500 m.

75

33

85

4

6

1-026S3

300

34-49

3-9

1-02741

100

34

43

6

6

1-02705

400

34-67

3-8

1- 02756

150

34

59

6

0

1-02725

200

34

61

5

3

1.09736

• 0

5-2

Sect. V, 11. May 30

Sect. V. 14. May 31

0

33

57

8

1

1-02616

10.50 p.m.-12.50 a.m.
N. 43° 38' 00"
W. 58° 35' 00"

25
50

32-79
32-86

5-0
3-85

1-02595
1-02612

12.55—2.30 p.m.

N. 43° 20' 00"
W. 56= 28' 30"

25
50

33
33

58
60

7
6

65
75

1-02624
1-02638

Over 500 m.

75

33-81

5-3

1-02672

Over .500 m.

75

33

74

7

5

1 02638

100

34-34

7-0

1-02693

85

34

72

8

35

1-02702

125

34-49

6-9

1-02705

100

34

77

8

4

1-02705

150

34-39

4-8

1-02724

125

34

69

7

0

1- 02719

200

3-8

150

34

70

6

75

1-02724

300

34-33

3-2

1- 02735

200

6

35

400

34-42

2-9

1- 02745

300

34

67

4

7

1-02746

400

34

75

4

7

1-0"' 7.53

0

32-61

4-55

1-02586

Sect. V, 12. May 31

Sect. V, 15. May 31

0

33

30

8

1

1-02594

4.30—6.35 a.m.
N. 43° 31' 00"
W. 57° 46' 00"

10
15

32-63

4-5
4-55

1-02588

7.15—9 p.m.
N. 43° 07' 50"
W. 55° 17' 5.5"

25
50

33
33

30
55

7
6

95
65

1-02.596
1-02635

Over 500 m.

20

-^0-3

Over 500 m.

75

33

44

5

8

1- 02636

25

32-81

-^0-3

1-02637

100

34

02

5

8

1-02682

50

32-82

H-115

1-02641

150

34

43

6

2

1-02710

75

32-94

-7-1-7

1-02651

200

fi

7

100

33 08

-^0-65

1-02661

300

34

68

5

6

1-027.36

125

33-24

0-4

1- 02669

400

34

61

4

25

1-02748

386

DEPARTMENT OF THE NATAL SERVICE

Table 16. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the spring of 1915 — Continued.

C. G. S. '-ACADIA."

Station, time,
position and depth.

Q

Salinity

i

Density

Station, time,
position and depth.

s

s:

D.

Q

Salinity

d

d
S

Density

Sect. V & VI, 16.

June 1
1.45— 3. 15 a.m.
N. 42° 53' 00"
W. 54° 09' 00"

0

25

50

75

100

150

200

300

400

Voo

35-01

.35-25

35-58
35-33

35 05
35-24
35-21

12-2
13-05
12-9
13-75
12 -.35
12-25
10-2
10-2
9-3

1
1

02658
02660

Sect. VI, 18— Con

100
150
200
300
400

"/oo

33-82
34-21

34-56
34-68

4-0

4-75

5-2

4-0

3-8

1-02687
1-02710

Over 500 m.

1
1

02671
02679

1- 02746
1- 02757

1
1

1

02696
02711
02726

Sect. VI, 19. June 1

8.1.5—10 p.m.
N. 44° 35' 00"
W. 54° 15' 00"

Over 500 m.

0

25
50
75
100
150
200
300
400

32-91
32-91
32-84
34-22
34-47
34-40

34 -.54
34-61

5-0
5-0
3-7
6-1
7-4
6-4
6-4
5-1
5-5

1 02604
1 02604
1 02613
1- 02694
1-02695
1- 02705

1 - 02733

Sect. VI, 17. June 1

9— 10.15 a.m.
N. 43° 30' 50"
W. 54° 12' 50"

Over .500 m.

0

25

50

75

100

150

200

300

400

34-90
3511

35-39
35-25

35-31
35 02

11-5

11-55
11-8
12-1
12-8
11-3
10-9
10-8
8-8

1-02664
1- 02673

1-02675
1-02692

1-027.34

Sect. VI, 20. June 2

1 a.m.
N. 44° 59' 00"
W. 54° 17' 00"

91 m.

0

25
50
75

.32-77
32-78
32-82
33-12

3-9
3-9

2-4
1-45

1-02605

1- 02707
1-02720

1-02606
1- 02622
1 02653

Sect. VI, 17a.

Jiine 1
1.10—1.25 p.m.

0
50

75
100

33-90

.35-34
35-38

8-8
12-2
120
12-05

1-02631

Sect. VI, 21. June 2

3.45— 4.45 a.m.

N. 45° 28' 00"
W. 54° 28' 00"

116 m.

0

35

50

65

100

32-71
32-87
32-87
33-06
33-24

2-2

11

1-05

^0-9

^1-3

1-02614
1-02635

N. 43° 56' 00"
W. 54° 16' 00"

Over 500 m.

1-02687
1-02690

1-02636
1-02660
1-02676

Sect. VI, 18.

June 1
4..30 p.m.
N. 44° 11'. 30"
W. 54° 13' 00"

0
25
40
50
60
75

32-89
32-88

32-84

34-16

4-8

41

2-9

2-8

8-25

7-3

1- 02606
1-02612

Sect. VI & VII, 22.

June 2

7.25—7.50 a.m.

N. 45° 50' 30"

W. 54° 20' 00"

73 m.

0
20
40
50
60

32-74
32-75
32-74
.32-88
33 03

3-4

3-0

1-4

-^0-25

-T-1-2

1-02606
1-02612

Over 500 m.

1-02621
1-02674

1-02622
1-02643
1-02658

CANADIAN FISHERIES EXPEDITION, Wl>,-15

387

Table 16. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the spring of 1915 — Continued.

C. G. S. "ACADIA."

Station, time,
position and depth.

B.
C

Q

Salinity

d

E

Density

Station, time,
position and depth.

Q

Salinity

6.

S

Density

Sect. VII, 23.

June 2
10.35 a.m.
N. 45° 39' 00"
W. 5.5° 03' 00"

100 in.

0
25
50
60
75

Voo

32-74

32-74

32-82

32-93

32-92

3-3

3-0

0-85

H-0-4

-=-0-5

1-02607
1-02610
1 02633

1 02647
1 02647

Sect. VII & VIII, 27.

June 3

2.10— 3.30 a.m.

N. 44° 06' 00"

W. 56° 54' 00"

Over .500 m.

0

25

50

75

100

lOObis

150

200

300

400

Voo

32-57
32-90
33-29
f 33-88
1 34-42
34-01

34-62
34-77

415

3-4

3-2

1-9

4-7

71

4-0

5-6

4-5

4-3

1-02602
1-02629
1- 02663
1-02684
1- 02695

Sect. VII, 24.

June 2
2.15—3.50 p.m.

N. 45° 16' 30"
W. 55° 29' 50"

120 m.

0

25
50

75
100

32-67

32-73
32-95
32-96

3-5

1-9

^0-6

H-1-35

^1-4

1-02601

1-02631
1-02653
1-02654

1-02702

1-02746
1-02759

Sect. VIII, 28.

June 3
6.15— 7.45 a.m.
N. 44° 12' 00"
W. 57° 24' 00"

Over 500 m.

0

25

50

75

100

125

150

200

300

400

31-73
31-89
32-00
32-59
32-97

34- 16

34-58
34-73

4-1

21

0-4

0-35

0-85

3-25

5-4

5-85

5-35

3-9

1-02.520
1-025.50
1 02569
1-02617
1-02645

1-02698

1-02733
1-02760

Sect. VII, 25.

June 2
5.40—6.30 p.m.
N. 44° 56' 00"
W. 55° 54' 00"

124 m.

0

25

50

75

100

120

32-77
32-83
33 05

33-17
33-36

3-4
2-45
0-9
■^0-6
005
0-35

1-02609
1-02622
1-02651

1-02665
1-02679

0

25

50

75

100

110

125

150

200

300

400

32-11
32-48
32-55

33-44

34-47
34-58

34-72
34-80

3-5

2-6

1-1

0-9

1-4

3-7

6-6

5-9

5-9

4-65

4-4

1- 02557
1-02593
1-02609

1-02679

1-02708
1-02726

1-02752
1- 02761

Sect. VII, 26.

Juno 2
10—11.15 p.m.
N. 44° 31' 00"
W. 56° 25' 30"

Over 500 m.

Sect. VIII, 29.

June 3

10.55 a.m. — 12 noon.
N. 44° 21' 36"
W. 58° 08' 00"

58 m.

0
20
30
40
55

31-69

31-79
32-23

4-6

40

2-25

2-2

0-0

1- 02512

1-02541
1-02590

Sect. VIII, 30.

June 3
3— 3.45 p.m.

N. 44° 40' 50"
W. 58° 42' 00"

127 m.

0

25

50

75

100

125

31-51
31-63
32-10
32-11
32-30
32-53

4-6

3-25

0-65

0-35

0-2

015

1-02498
1-02.520
1-02575
1-02578
1-02594
1-02613

388

DEPARTMENT OF THE NATAL SERVICE

Table I&. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the spring of 1915 — Concluded.

C. G. S. " ACADIA.'

Station, time,
position and depth.

Q.

0)

Q

Salinity

O
a

6

Density

Station, time,
position and depth.

S

a.
P

Salinity

d
a

Density

Sect. VIII, 31.

June 3
7.30—8.30 p.m.
N 45° 13' 00"

0
25
50

75

85

31-24
31-35
31-99
32 15

4-75

3-1

-0-2

^0-3

H-0-3

1-02476
1-02498
1-02571
1-02584

Sect. IX, 34— Con.

50
75

Voo
32-30

-0-4

^0-5

^0-45

1-85

4-2

1-02597

W. 58° 59' 00"
85 m.

100
200
300

32-51
33-45
-34-43

1-02614
1-02676
1-02734

0

25

50

75

100

150

31-37
31-68
31-83

32-48
32-99

4-5
2-55
1-9
00
H-0-35
0-45

1-02488
1-02531
1-02546

1-02611
1-02649

Sect. VIII, 32.

June 3
11.15 p.m.-12.15 a.m.

N. 45° 48' 30"
W. 59° 13' 00"

155 m.

Sect. IX, 35. June 4

11. .55 a.m. — 12. 55 p. m
N. 47° 04' 00"
W. 58° 26' 00"

Ca. 4)0 m.

0

15

30

50

75

100

150

200

300

400

32-15
32-21
32-24
32-49
32-83
33-05
33 - 66

34 -.56
34-66

4-5

4-2

2-7

0-45

0-25

0-7

2-1

3-6

4-2

4-05

1-02549
1-02557
1-02573
1-02604
1-02637
1-02652
1-02690

1-02744
1-02753

Sect. VIII & IX, 33.

June 4

3.50-^.50 a.m.

N. 46° 16' 30"

W. 59° 33' 00"

Ca. 73 m.

0
10
15
20
25
40
50
75

30-55

30-56

31-07
31-49
31-68
32-29

4-0
40
3-35
2-3
1-25
H-0-15
-^0-5
^0-55

1-02428

1-02434

1-02490
1-02531
1-02547
1-02596

Sect. IX, 36. June 4

3.30-^.30 p.m.

N. 47° 26' 00"
W. 57° 57' 00"

230 m.

0

15

25

50

60

75

100

135

200

32-02

32-17
32-49

32-01

33-16
33-81

4-3
3 - 35

1-02542

1-9

0-45

H-0-2

H-0-45

^0-35

0-4

2-3

1-02573
1-02608

Sect. IX, 34. June 4

7.45 — 8.45 a.m.
N. 46° 40' 00"
W. 59° 00' 00"

Ca. 350 m.

0
15
25
35

31-97
32-01

4-0
3-9
11
0-0

1-02541
1-02566

1-02622

1-02663
1- 02702

CANADIAN FISHERIES EXPEDITION, Wl-'rlo

389

Table Ic. — Salinity, Temperature and Density of the water in the Gulf of
St. Lawrence during the summer of 1915.

C. G. S. "PRINCESS".

Station, time,

E

C

Station, time,

s

6

j:

Salinity

6.

Density

ji

Salinity

Density

position and depth.

o.

a;

position and depth.

1

c

H

P

E^

Voo

"

Voo

o

Stat. 27. Aug. 3

0

27-86

16-4

1-02021

Sect. X, 32. Aug. 4

0

28-55

17-0

1-02060

5.30—6.30 p.m.

10

28-19

16-5

1-02044

4.55—5.50 p.m.

10

29-49

14-95

1-02277

N. 46° 02'

N. 48° 00'

W. 63° 24'

20

29-69

8-4

1-02308

W. 63° 25'

25

31-04

5-45

1-024.52

23 m.

87 m.

40
50
75

31-76
32-05

1-4

0-55

H-0-25

1-02,549

1-02576

Stat. 28. Aug. 3

0

27-63

18-5

1-01955

85

32-13

-rO-3

1-02583

11.45 p.m. -1.30 a.m.

10

27-72

17-1

1-01995

N.46°31'

W. 64° 20'

15

17-0

Sect. X, 33. Aug. 4

0

29-80

15-55

1-02089

23 m.

20

27-85

17-0

1-02007

8..55— 9.50 p.m.

10

29-97

10-35

1-02.300

N. 48° 17'
W. 62° 54'

25

31-23

2-5

1-02494

Sect. X, 29. Aug. 4

0

26-63

17-0

1-01914

78 m.

50

32-04

-e-0-95

1-02578

6.10 — 7.15 a.m.

10

27-45

15-6

1-02007

X. 47° 13'

75

32-69

-^0-5

1-02629

W. 64° 36'

15
20

28-24
28-91

10-7
9-3

1-02161
1- 02234

32 m.

Sect. X, 34. Aug. 4

0

30-11

15- 15

1-02220

25

29-08

8-1

1-02265

11.55 p.m. -2. 25 a.m.

10

30-90

11-75

1-02348

N. 48° 27'
W. 62° 37'

25

31-17

7-8

1-02432

Sect. X, 30. Aug. 4

0

27-85

16-1

1 02027

405 m.

50

32-05

^0-55

1-02577

lO.lf)— 11.05 a.m.

10

27-83

15-7

1-02033

N.47°31'

75

32-47

-M-15

1-02613

W. 64° 09'

25

' 28-67

10-5

1-02197

100

32-89

H-0-3

1-02644

66 m.

40
50
60

29-49
30-37
31-64

7-9

5-65

0-45

1-02299
1-02397
1-02540

150
200
300
350

33-51
33-96
34-59
34-72

1-0
3-0
4-45
4-45

1 02687
1-02708
1-02744

1-02753

Sect. X, 31. Aug. 4

0
10

27-37
27-44

16-55
13-9

1-01970
1-02041

1.35— 2.40 p.m.

N.47°47'

Sect. X, 35. Aug. 5

0

30-24

12-85

1-02276

W. 63° 45'

25

29-16

8-45

1- 02266

4.40—6.35 a.m.

10

30-51

12-9

1-02296

65 m.

40

30-57

7-5

1-02389

N. 48°41'

W. 62° 15'

25

31-44

3-4

1-02493

50

31-47

1-4

1-02527

Ca. 400 m.

50

32-25

-^0-6

1-02595

60

31-94

^0-35

1-02567

75

32-55

■^0-75

1- 02618

390

DEPARTMENT OF THE NAVAL SERVICE

Table Ic. — ^Salinity, Temperature and Density of the water in the Gulf of
St. Lawrence during the summer of 1915^ — Continued.

C. G. S. " PRINCESS."

Station, time,
position and depth.

s

Xi
a.

Q

Salinity

d

£

Density

Station, time,
position and depth.

E

n

Q

Salinity

Temp. C.

Density

Sect. X, 35— Con.

100
150
200
300
350

Voo

32-84
.33-26
33-89
34-56
34-65

^0-3
-^0-4
2-8
4-35
4-45

1- 02640
1-02674
1-02704
1-02742
1-02748

Sect. X, .39. Aug. 5

7.00— 8.35 p.m.
N. 49° 45'
W. 61° 19'

284 m.

0

10

25

50

75

100

150

200

275

Voo

30-15

30-24

31-76

32-36

32-68

32-96

33-18

33-48

34-29

13

13

2

^1

H-1

--0

-=-0

0

3

9

65

6

0

1

8

75

9

95

1-02249
1-02260
1 02536
1 02604
1-02630
1-02652
1-02669
1-02685
1-02735

Sect. X, 36. Aug. 5

9.30—10.20 a.m.

N. 48° 58'
W. 61° 48'

53 m.

0
10
25
35
50

29-91
29-90
30-62
31-71
31-96

14-3

14-2

7-6

1-3

0-3

1-02221
1-02222
1-02389
1-02540
1-02567

Sect. X & XI. 40.

Aug. 5
11.30 p.m.-12.25 a.m.
N. 50° 05'
W. 61° 16'

68 m.

0
10
25
40
50
65

29-43
31-18
31-72
32-09
32-30
32-30

11

7

1

^0

-^0

-^0

65
05
3

2

6

7

1-02199
1-02443
1-02541
1-02579

Sect. X, 37. Aug. 5

0
10
15
25
40
50
70

30-14
30-15

31-46

32-21
32-60

13-05
12-5
8-65
2-35
^0-4
^0-85
-Ml

1- 02265
1-02277

1-02513

1-02591
1- 02624

1-02597
1-02598

12.45— 1..35 p.m.
N. 49° 06'
W. 61° 21'

75 m.

Sect. XI, 41.

Aug. 6
3.30— 4.55 a.m.
N. 49° 54'
W. 60° 37'

189 m.

0

10

25

50

75

100

150

180

30-32
30 -.35
31-13
31-89
32-46
32-77
33 05
33-51

13

13

5

0

-M

H-0
H-0

1

25

35

2

4

1

95

65

25

1-02275
1 02276
1- 02462
1-02560
1-02612
1-02637
1-026.58
1-02685

Sect. X, 38. Aug. 5

4.00— 5,00 p.m.

N. 49° 28'
W. 61° 22'

180 m.

0

10

25

50

75

100

150

175

29-96
29-97
31-74
32 -.36
32-73
32-95
33-31
33-41

13-95

130

1-9

^0-95

-hl-1

H-0-95

^0-2

1-3

1-02233
1-02253
1-02540
1-02604
1- 02634
1- 02652
1-02678
1-02678

Sect. XI, 42.

Aug. 6
4.25— 8.00 a.m.
N. 49° 45'
W. 60° 07'

90 m.

0
10
25
40
50
75
85

30-53
30-54
31-23

32-01
32-68
32-70

12
12

7

5

0

^1

-T-1

65
65
35

4
65
0
0

1-02303
1- 02304
1- 02443

1-02568
1- 026.30
1 02631

CANADIAN FISHERIES EXPEDITION, 191.1,-15

391

Table Ic. — Salinity, Tomporaturo and Density of the water in the Gulf of
St. Lawrence during the summer of 1915 — Continued.

c. G. s.

PRINCESS."

Station, time,
position and depth.

s

Q,

D

Salinity

d

S

Density

Station, time,
position and depth.

o.

o

Q

Salinity

d

d

S
o

Density

Voo

°

Voo

"

Sect. XI, 43.

Aug. 6
11.00 a.m. -12.00 noon
N. 49° .33'
W. 59° 28'

0
10
25

30-72
30-73
31-39

13-4
13-4
7-05

1-02303
1-02.304
1-02458

Sect. XII, 40.

Aug. 12
5.2.5—6.35 a.m.
N. 47° 41'
W. 59° 52'

0
25
50

31-37
31-60
32-52

12-75
8-3
3-55

1-02.365
1-02459
1- 02588

265 m.

50

31-97

0-05

1 02568

75

32-57

0-8

1-02613

75

32-59

^0-85

1-02622

Ca. 455 m.

100

32-72

-0-1

1 02629

100

32-83

^0-8

1 02641

150

33-30

0-8

1 02671

150

3317

-hO-55

1-02667

200

33-91

2-8

1 02706

200

33-71

1-85

1-02697

300

34-52

4-2

1 02741

250

34-27

3-75

1- 02726

400

34-70

4-15

1-027.54

Sect. XI, 44.

Aug. 6
2.30—3.10 p.m.
N. 49° 24'
W. 58° 55'

0
10
25

30-68
30-69
31-29

13-45
13-4
5-5

1-02299
1-02301
1- 02471

Sect. XII, 47.

Aug. 12
8.35— 10.00 a.m.
N. 47° 25'
W. 60° 10'

410 111.

0
25
50
75

29-82
31 13
31-84
.32-41

14-35

12-15

5-95

2-95

1-02215
1- 02358
1 02509
1-02.584

157 m.

50

32-10

^0-3

1 - 02580

100

32-60

0-65

1-02616

75

32-52

-hO-75

1-02616

125

0-0

100

32-79

H-0-65

1-02638

1,^.0

33-22

0-55

1-02667

150

33-20

0-0

1-02668

175
200
300

33-65
34-36

1-5
1-7
3-9

1-02693

1 02731

Sect. XII, 45.

Aug. 12
2.05—3.50 a.m.
N. 47° 53'
W. 59° 38'

380 m.

0

25

50

75

100

31-71
31-92
32-32
32-57
32-60

12-45

11-35

5-7

2-8
1-2

1-02396
1-02434
1-02550
1 02599
1-02613

400

34-71

4-4

1- 02753

Sect. XII. 4S.

Aug. 12
12.40— 2.00 p.m.
X.47°08'
W. 60° 31'

0
25
50

29-72
31-29
31-97

16-2
8-9
0-5

1-02168
1-02426
1- 02566

150

32-75

0-2

1-02631

175 111.

75

32-65

0-35

1- 02621

200

33-30

0-7

1-02672

100

32-88

0-2

1 02641

300

34-45

115

1-02761

125

33-58

1-8

1 02687

375

34-66

4-0

1-02764

170

33-91

2-65

1-02707

392

DEPARTMENT OF THE NAYAL SERYICE

Table Ic. — Salinity, Temperature and Density of the water in the Gulf of
St. Lawrence during the summer of 1915 — Concluded.

C. G. S.

PRINCESS."

Station, time,
position and depth.

£
Q.

Q

Salinity

6

d

S

c

Density

Station, time,
position and depth.

Q

Salinity

d

s

Eh

Density

Voo

°

Voo

°

Sect. XII, 49.

Aug. 12
6.25—7.05 p.m.

N. 46° 40'
W. 61° 14'

0
10
25

28-55
28-59
30-43

17-05
16-9
5-25

1-02051

1-02083
1-02405

Sect. XII, 50.

Aug. 12
11.25 p.m. -12. 20 a.m.

N. 46° 18'
W. 61° 59'

0
10
25

28-60
28-62
29-23

16-15

16-2

10-65

1-02084
1- 02086
1-02238

75 m.

35

31-43

-0-5

1-02527

42 m.

30

4-9

50

31-56

-^1-1

1-02540

40

30-81

0-2

1-02474

60

31-82

H-1-05

1-02560

70

32-38

0-4

1-02599

«

STEAM DRIFTER "33".

•02260
-02352
-02510
-02577
-02594
-02606
-02621
•02623
-02625

Stat. 54. Aug. 7

9.15 a.m.

South Arm,
Bay of Islands,
Newfoundland.

110 m.

Stat. 58. Aug. 10

11.10 a.m.
OfT South Head,
Bay of Islands.

50 m.

0

22-45

15-2

1-01633

10

30-59

10 75

1-02340

25

31-55

4-2

1-02504

50

31-83

2-25

1-02544

75

32-27

0-1

1- 02593

100

32-37

^0-2

1-02601

108

-hO-25

0

30-32

13-7

1-02266

10

30-95

12-3

1-02342

25

31-60

5-4

1-02497

45

31-98

1-2

1-02563

Stat. 59. Aug. 10

12.50 p.m

Inside South Head

Bay of Islands

275 m.

0

29-22

14-75

10

31-00

12-0

25

31-67

4^7

50

32-01

10

75

32-29

0^15

100

32 42

-^0•25

150

3261

^0-3

200

32 63

-r-035

270

32 65

-=-0-4

CA^ADIAy FISHERIES EXPEDITION, JOl-i-lo

393

Table Id. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the summer of 1915.

C. G. S. "ACADIA."

Station, time,

E

C

Station, time,

E

d

s:

Salinity

d

Density

j=

Salinity

d

Density

position and depth.

a.

s

position and depth.

a

o

Q

s
e2

»'oo

°

Voo

"

Sect. XIII, 37.

0

3116

9-7

1-02403

Sect. XIII, 41.

0

34-27

18-35

1-02465

July 21

July 22

5..30p.m.

20

31-47

5-8.=

1-02481

5.25 a.m.

2f

35 07

18-95

1-02510

X. 4.3° .33 '00"

X. 42° 17' 00"

W. 65° 12' 50'

40

31-77

2-5

1-02538

W. 64° 30' 30"

40

15-6

62 m.

60

31-9.'^

1-95

l-0255f

420 m.

50

35-33

13-9

1 02647

75
100

35-25
35-35

13 05
12-5

1- 02659

1- 02678

Sect. XIII, 38.

0

31 02

12-4

1-0234.'

July 21

150

35-42

11-85

1-02695

7.50 p.m.

25

31-7C

10- 7c

1-02427

N. 43° 14' 00"

20C

35-40

11-3

1-02705

W. 65° 02' 00'

50

31-64

51

1-02503

30C

35- 14

8-95

1- 02727

170 m.

75
100

3201
32-92

1-9
4- 1£

1-02563
1-02614

40C

35 08

7-2

1-02747

Sect. XIII, 42.

0

34-33

18-7

1-02460

I2c

33-04

3-9

1-02627

July 22

9.00 a.m.

2i

3511

19-2

1-02507

150

33-22

3-8£

1-02641

X. 41= .58' 00"

W. 64° 20' 00"
Over 1,000 m.

50

75

IOC

35-21
35-38
35-33

14-35
13-15
12-2

1- 02630
1-02667
1-02682

Sect. XIII, 39.

0

31-24

12-5

1-02361

July 21

10.55 p.m.

21

31-27

9-5

1-02415

150

35-43

11-65

1-02700

X. 42° .55' 00"

W. 64° 51' 00"

40

31-43

7-7

1-02453

200

35-40

10-85

1-02713

95 m.

50

31-9.'

3-8

1-02541

30C

35-12

8-8

1-02727

7t
90

32 -3^
.32-43

3-U
3-2

1-02582
1-02584

400

35-09

7-4

1-02745

Sect. XIII, 43.

0

33-69

171

1-024.50

July 22
11.50 a.m.
X. 41° 38' 30"

21

34-59

180

1-02498

Sect. XIII, 40.

0

30-90

13-5

1-02314

W. 64° 10' 00"

50

34-62

15-75

1 02554

Julv 22

2.00 a.m.

25

33-02

I0-6£

1-02532

Over 1,000 m.

75

35-82

16-05

1 02638

' X. 42° 36' 00'

W. 64° 41 '00'

50

33-46

8-6

1 02595

100

35-82

15-8

1-02644

134 m.

60

7-05

150

35-62

13-75

1-02674

75

33-66

6-6

1-02643

200

35-47

12-95

1-02679

100

33-81

6-4

1-02659

300

35-42

11-2

1-02709

125

34 05

61

1 02681

400

35-12

8-4

1-02733

394

DEPARTMENT OF THE NATAL SERVICE

Table Id. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the summer of 1915 — Continued.

C. G. S. "ACADIA."

Station, time,

£

^

Station, time,

£

d

JS

Salinity

a.

Density

^

Salinity

d

Density

position and depth .

a
Q

2
o

position and depth.

o.

a

Q

Voo

°

Voo

"

Sect. XIII & XIV,

0

33-99

19-7

1-02411

Sect. XIV, 47.

0

31-31

13 ,35

1-02449

44. July 22

July 23

.3.10 p.m.

25

35-25

21-9

1-02445

6.30 a.m.

25

31-42

12-25

1-02478

N. 41° 19' 00"

N. 43° 15' 00"

W. 63° 59' 00"

50

35-90

19-9

1-02549

W. 63° 13' 30"

50

32-69

6-7

1-02566

Over 1,000 m.

75

35-99

17-3

1-02622

144 m.

75

33-47

5-2

1- 02656

100

35-57

13-9

1-02667

100

34-36

8-35

1-02674

150

35 - 35

11-95

1-02691

125

34-52

8-05

1-02691

200
300

35-44
35-25

11-6
9-45

1-02702
1-02724

Sect. XIV. 48.

0

30-99

13-1

1-02329

400

3511

7-5

1-02749

July 23

11.00 a.m.

25

31-62

10-5

1-02425

N. 43° 53' 30"
W. 62° 58' 30"

50

32-56

2-75

1-02598

Sect. XIV, 45.

0

33-73

16-3

1- 02472

July 22

264 m.

75

.32-94

2-75

1-02628

8.10 p.m.

25

34-28

17-65

1-02483

N. 42° 02' 00"

100

.33-70

5-4

1-02662

W. 63° 43' 00"

50

34-74

15-2

1-02575

125

34-40

7-3

1-02693

Over 1,000 m.

75
100
150
200
300

34-60
35-23
35-40
35-34
35-08

11-75
13-0
12-2
11-3

7-7

1-02634
1-02659
1-02688
1-02702
1-02745

150
200
250

34-67
34-87
34-82

8-1
8-2
7-55

1-02702
1-02716
1-02723

Sect. XIV & XV, 49

• 0

30-62

13-05

1-02302

400

35-04

6-2

1-02758

July 23

3.35 p.m.

25

31-80

9-2

1-02461

N. 44° 30' 30"
VV. 62° 43' 00"

40

31-98

3-35

1-02547

Sect. XIV, 46.

0

.32-46

,170

1- 02359

July 23

*

135 m.

50

32-13

3-3

1-02560

12.50 a.m.

25

32 05

10-5

1-02459

N. 42° 31' 00"

75

32-21

0-95

1-92583

W. 63° 31' 30"

50

33-58

7-5

1-02625

100

32-35

10

1- 02594

Over 1,000 m.

75

33-96

7-8

1-02651

125

32-59

1-15

1 02613

100
150

33-99
35-15

7-3
10-7

1-02660
1-02696

Sect. XV, 50.

0

3118

13-3

1-02340

200

34-92

9-4

1-02700

July 23

7.30 p.m.

25

31-90

8-9

1-02473

300

35-23

8-45

1-02740

N. 44° 12' 15"
W. 62° 35' 00"

40

3-25

400

34-94

6-9

1-02741

155 m.

50

32-63

3-3

1-02599

CANADIAN FISHERIES EXPEDITION, lOU-15

395

Table Id. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the summer of 1915 — Continued.

C. G. S. "ACADIA."

Station, tiino.

i

C

Station, time.

c

d

■£

.Salinity

d

Density

Si

Salinity

d

Density

position and depth.

a.
Q

s

o

position and depth.

1

Q

Voo

o

Voo

o

Sect. XV, 50— Con.

75

33 03

3 -.35

1-02631

Sect. XV, .54.

July 24

0

31-94

13-9

1-02.386

100

33-64

5-05

1-02661

7..30a.m.
N. 42° .57' 30'

25

.32-66

11-0

1-02498

125

33-99

6-05

1-02677

W. 61° .34 '00'

40

5-1

150

84-23

6-9

1-02684

Over 1,000 m.

50

75

100

33-45
33-87
33-93

5-05

4-7

4-95

1 02646
1-02683

1-02685

Sect. XV, .51.

0

31-44

12-95

1-02367

Julv 23

150

34-69

7-3

1-02715

10.2.5 p.m.

25

32-01

10 -.35

1-024.58

X.4.r .52'00"

200

34-96

8-5

1- 02719

W. 62° 18' 00"

40

.32-81

5-05

1-02595

300

34-89

5-3

1-02757

133 111.

50

75

100

.32-94
.33-46
33-99

4-45
4-6

6-2

1-02612
1-02652
1-02675

400

34-93

4-9

1 02765

Sect. XV, 55.

0

32-03

16-35

1-02342

Julv 24

125

.34-22

7 05

1-026S1

10.25 a.m.
N. 42° 41' 15"

25

.32-67

9-4

1-02526

W. 61° 21' 00'
Over 1,000 m.

50
75

.33-46
34-69

6 -.35
9-85

1- 02630

1-02675

Sect. XV, 52.

0

31-97

12-7

1-02412

July 24

100

34-31

7-85

1-02677

1.45 a.m.

25

32-23

9-4

1-02492

X. 4.3° 31' 00"

150

35-20

10-1

1-02711

W. 62° 01' 00"

40

32-59

4-4

1-02583

200

35-01

8-95

1-02717

95 m.

.50
60
75
90

32-76
33-01
33-03
33-56

3-4
2-95
2-55
4-15

1-02609
1-02630
1-026.38
1-02665

300
400

34-88
, 34-95

7-3
5-95

1-02727
1-02754

Sect. XV & XVI, 56

0

31-65

17-6

1-02283

July 24

9 1 f^ r\ tn

25

32-72

9-45

1-02529

^.\u p. Ill .

X.42° 16' 00"

Sect. XV, 53.

0

32-20

12-2

1-02440

W. 61° or 00"

50

35-59

15-45

1-026.34

July 24

4.45 a.m.

25

32-26

6-65

1- 02533

Over 1,000 m.

75

14-05

N. 43° 14' 30"

W. 61° 48' 00"

40

32-68

1-8

1-02615

100

35-42

13-05

1- 02672

99 m.

50

32-77

1-8

1-02622

150

35-37

11-55

1- 02699

60

1-85

200

35-35

11-35

1-02700

75

33 00

1-9

1-02640

300

.35-21

9-2

1-02728

95

33-13

2-1

1-02649

400

35-01

7-8

1-02734

6551—29

396

DEPARTME^fT OF THE NATAL SERVICE

Table Id. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the summer of 1915 — Continued.

C. G. S. "ACADIA."

Station, time,

£

O

Station, time.

£

O

X

Salinity

d

Density

^

Salinity

d

Density

position and depth.

o

Q

S
H

position and depth.

a.

Q

E

Voo

°

«/00

o

Sect. XVI, .57.

0

.32-84

17-5

1-02376

Sect. XVI, 62.

0

31-08

11-6

1-02364

July 24

July 25

7.18 p.m.

25

32-67

10-45

1-02508

10.05 a.m.

25

31-31

9-35

1-02420

N. 42° 57' 30"

N. 44° .34' 30"

W. 60° 56' 00"

50

33-30

6-6

1- 02615

W. 60° 47' 00"

40

31-67

3-9

1-02518

Over 1,000 m.

75

.33-63

4-75

1 02664

62 m.

50

31-96

2-5

1- 02552

100

33-96

5-2

1-02684

60

32 08

1-8

1- 02567

150
200

34-56
34-61

6-45
5-75

1-02716
1-02731

Sect. XVI, 63.

0

31-04

11-8

1-02.361

July 25

300

35 06

6-8

1 02752

11.55 a.m.

N. 44° 43' 30"

25

31-54

6-7

1-02476

400

34-98

5-5

1-02763

W. 60° 46' 00"
55 m.

50

32 13

21

1- 02568

0

32-28

14 65

1- 02.398

Sect. XVI, 58.

.July 24

Sect. XVI, 64.

0

30-39

12-3

1-02298

10..35 p.m.

25

.32-74

10-5

1-02512

July 25

N. 43° 23' 00"

2.30 p.m.

25

31-15

9-65

1- 02403

W. 60° 53' 00"

50

.33-20

5-5

1-02622

N. 4.5° 04' 00"

W. 60° 46' 00"

50

31-74

5-1

1- 02.511

187 m.

75

33 -.30

5-4

1-02630

120 m.

75

32-24

0-35

1-02589

100

33-64

3-5

1-02677

110

32-52

0-4

1-02613

125
150

34-20
34-36

61
6-2

1- 02693
1-02704

Sect. XVI & XVII,

0

29-85

12-3

1-02257

175

34-76

7-85

1-02713

65. July 25

5.15 p.m.

10

30-35

11-8

1- 02305

N. 45° 17' 00"

W. 60° 42' 30"
105 m.

25

30-92

5-7

1-02440
1-02555

Sect. XVI, 59.

0

31-73

11-55

1-02415

50

31-88

1-25

July 25

12.00 noon.

15

31-75

11-3

1-02422

75

32-00

0-75

1-02567

N. 43° 48' 30"

W. 60° .50' 00"
45 m.

30
45

31-92
32-21

8-45
4-55

1-02496
1-02554

100

.32-21

0-45

1-02585

Sect. XVII, 66.

July 25

0

30-58

11-85

1-02321

Sect. XVI, 60.

0

31-80

13-3

1-02388

7.55 p.m.

10

30-61

11-7

1-02325

July 25

N. 4.5° 08' 00"

5..53 a.m.

25

32-22

9-6

1-02487

W. 60° 23' 00"

25

.30-59

11-6

1- 02327

N. 44° 13' 30"

W. 61° 14' 00"

50

32-73

4 -.35

1- 02.597

64 m.

40

31-09

5-9

1-02451

98 m.

75

33-17

3-5

1-02641

50

31-67

1-8

1-02535

95

33-46

4-3

1-02655

60

32-06

0-35

1-02574

CANADIAN FISHERIES! EXPEDITION, JOl.'rlo

397

SESSIONAL PAPER No. 38b

Table Id. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundhind banks during the summer of 1915 — Continued.

C. G. S. "ACADIA."

Station, time.

c

c

Station, time.

£

c

S

Salinity

d

g

Density

■z

Salinity

d

Density

position aiul depth.

c.

position and depth.

a.

t

C

h

^

h

"/oo

°

Voo

Sect. XVII, 67.

0

31 05

11-95

1-02355

Sect. XVII, 71.

0

32 01

15-15

1-02397

July 2.5

Julv 26

11.55 p.m.

10

31

05

11

9

1-02.3.56

2.30 p.m.

25

32

65

9-8

1 02.517

N. 44° 49' 00"

X. 43° .57' 00"

W. .59° 40' 00"

25

31

52

8

65

1-02447

W. 57° 46' 30"

50

33

00

4-3

1-02619

205 in.

40

4

55

Over 1,000 m.

75

33

64

3-9

1 02674

50
75

32
32

21
47

1
0

45
55

1-02579
1-02606

100

34

19

5-6

1-02698

Sect. XVIII, 72.

0

32

01

161

1 02.346

July 26

100

32

53

0

45

1-02611

3.45 p.m.

10

12-55

N. 43° 51' 30"

150

32

75

0

65

1-02629

VV. 57° 33' 00"

25

32

83

9-1

1- 02542

200

32

89

0

8

1-02639

Over 1,000 m.

50
75

33
33

04
26

2-6
0-85

1- 02638

Sect. XVII, 68.

0

31

32

11

65

1-02382

1-02668

July 20

3.55 a.m.

10

31

38

10

8

1-02401

100

33

95

4-7

1 02689

X. 44° .32' 00"

W. 59° 04' 00"

25

32

01

3

85

1-02545

150

35

01

9-3

1 02710

54 m.

40

32

12

2

4

1-02566

200

35

04

8-9

1-02719

50

32

26

1

95

1-02580

300
400

34
34

49
88

4-0
5-6

1-02740

Sect. XVII. 69.*

0

30

90

10

95

1-02361

1-02753

July 26

8.05 a.m.

10

30

89

10

8

1- 02363

Sect. XVII, 73.

0

32

54

17-6

1-02351

N. 44° 19' 15"

July 26

W. 58° 36' 00"

25/

I

31
31

37
83

9
6

9
3

1 02416
1 02503

5.45 p.m.
X. 43° 46' 00"
W. 57° 21' 00"

25
50

32
32

72
99

9-8
1-35

1-02.523
1-02644

64 m.

40/

32

18

2

25

1 02571

I

32

26

1

95

1-02580

Over 1,000 m.

75

33

84

5-2

1 02676

50
60

32
32

27
20

1
4

95
45

4 02581
1- 02554

100

34

59

8-4

1-02692

Sect. XVII. 74.

0

32

90

18-45

1-02357

July 26

7.00 p.m.
N. 43° 41' 00"

10

13-4

Sect. XVII, 70.

0

31

91

13

9

1-02397

July 26

W. 57° 08' 00'

25

34

79

16-65

1-02546

11.40 a.m.

25

32

57

8

25

1-02535

N. 44° 05' 00"

Over 1,000 m.

50

34

31

10-2

1- 02639

W. 58° 05' 00"

50

33

08

4

2

1-02626

75

35

39

13-25

1-02666

Over 1,000 m.

75
100
150
200
300

33
34
34
34

34

49
15
57
77
62

3
5
6
6
4

2

55

25

3

3

1-02668
1-02696
1-02720
1-02735
1-02748

100
150
200
300
400

35
35
35
35
34

42
37
28
05
83

12-8

11-7

10-95

8-45

60

1-02678
1-02696
1- 02702
1- 02726
1-02744

400

34-76

415

1-02759

The figurc-j for this station are not reliable, owing to some fault in taking the observations.

398

DEPARTMENT OF THE NAVAL SERYICE

Table Id. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the summer of 1915^ — Continued.

C. G. S. "ACADIA."

Station, time,
position and depth.

s

D.

Q

Salinity

d

s

Density

Station, time,
position and depth.

£

D.

C

Q

Salinity

6.

E

o

Density

Sect. XVII &

XVIII, 75. Julv2r)
10.55 p.m.

0

10

25

50

75

100

150

200

300

400

Vuo

32-81

33 06

34-63

34-78

35-59

35-51

35-41

35-35

35-15

34-63

16-0
16-4
17-45
16-1
14-5
13-2
12-2
11-2
8-9
4-7

1-02408
1-02418
1 02514
1-02558
1-02656
1-02676
1 02689
1-02704
1-02728
1-02744

Sect. XVIII, 78.

July 27
10.15 a.m.
N. 44° 33' 00"
W. .55° 29' 00"

Over 1,000 m.

0

25

50

75

100

Voo
32-38

15-35

1-02.389

N. 43° 30' 00"
W. 56° 43' 00"

Over 1,000 m.

33-36
33-48
34-41

40

2-35
6-75

1-02651
1 02675
1-02701

Sect. XVIII &
XIX, 79. July 27
12.05 p.m.

N. 44° 47' 00"
W. ,55° 13' 00"

410 m.

0

10

. 25

50

75

100

150

200

300

400

.32-42
.32 ,53
.32-85
33-06
.33 -.33
33-97
34-40
34-60
34-61
34-72

13-05

11-1
9-5
5-5
2-5
4-9
5-9
6-2
4-65
4-15

1-02441
1-02486
1-02538
1-02610
1-02662
1-02689
1-02711
1-02722
1-02743
1-02756

Sect. XVIII, 76.

July 27
2.45 a.m.
N. 43° 55' 30"
W. 56° 13' 00"

Over 1,000 m.

0

10

25

50

75

100

150

200

300

400

30-49

31-33
32-68
33-00
33-98
34-43
34-58
34-67
34-84

13-85
13-6
8-65
1-75
0-0
5-65
6-2
5-45
4-2
4-65

1-02276

1- 02432
1-02616
1-02652
1-02681
1-02709
1-02732
1-02752
1-02760

Sect. XIX, 80.

July 27
3.40 p.m.
N.45° 17' 00"

W. .5.5° 27' 00"

1.55 in.

0

10

25

40

50

75

100

125

150

31-97
32-00
32-21
32-57
3.2-72
.33-02
33 07
33-10
33-10

12-3

11-2

8-7

41

1-25

-M-05

-^1-3

H-1-2

^1-2

1-02420
1- 02442
1-02500
1-02587
1-02622
1-02657
1-02662
1-02663
1-02663

Sect. XVIII, 77.

July 27
7.25 a.m.
N.44°21' 15"
W. 55° 42' 30"

Over 1,000 m.

0

10

25

50

75

100

150

200

300

400

31-27
31-92
33-35
33-17
33-40
33-86
34-37
34-53
34-70
34-75

15-3
13-55
11-65
40
3-15
5-0
5-8
5-3
4-9
4-3

1-02305
1 - 02389
1-02540
1-02635
1-02662
1-02679
1-02710
1-02729
1 02747
1-02757

Sect. XIX, 81.

July 27
7.20 p.m.
N. 45° 48' .30"
W. 55° 43' 00"

56 m.

0
10
25
40
54

32-17
32-16
32-50
32-64
32-65

11-65
10-85
6-3
3-05
2-5

1-02448
1-02462
1-02556
1-02002
1-02607

CANADIAN FISHERIES! r.irKDJTION, 1914-15

399

Fable Id.— Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the summer of 1915 — Continued.

C. G. S. "ACADIA."

Station, time,
position and deptli.

£

o.

Q

Salinity

U
H

Density

Station, time,
position and depth.

E

D.

c

Salinity

d

Den.sity

Sect. XIX, 82.

July 27
10.00 p.m.
N.46° 11' 00"
W. .').5°54'00"

58 m.

0
10
25
40
50

Voo

32-20

32-20

32-38

.32-42

32-70

1215
12- 15
8-8
5-9
0-95

1-02442
1-02442
1-02.511
1 02.555
1- 02622

Sect. XX, 86.

July 28
11.10 a.m.
N. 4.')° 47' 00"
\V. 57° 34' 00"

455 m.

0

25

40

50

75

100

150

200

300

400

Voo
31 14
32-86

32-92
33-17
33 -.33
34-16
34 -.36
.34 -.58
34-78.

13-8
8-9
5-4
20
^0-4
1-4
4-5
4-85
41
4-0

1 02327
1-02.548

1-02628
1 02607

Sect. XIX & XX,
83. July 28

12.45 a.m.
N. 46° 32' 00'
W. 56° 04' 00"

172 m.

0

10

25

50

75

100

125

150

170

31-89

31-96
.32-56
32-73
32-82
32-91
.33-00
33 04

11-3

10-75

8-75

1-3

-r-0-05

H-0-8

-4-1-2

-T-1-45
-hl-4

1-02433

1-02480
1-02609
1-026.30
1 02040
1-02648
1-02656
1-02660

1 02670
1- 02709
1 02720
1 02747
1-02763

Sect. XX, 87.

July 28
2.15 p.m.
N. 45° 38' 30"
W. .57° 59' 30'

330 m.

0

15

25

50

75

100

150

200

300

31-36
32- 16
32-73
32-94
33-10
33-31
.34 07
34-23
34-63

14 Oo
10-9
7-95
2-0
^0-4
1-15
4-75
3-95
4-3

1 02327
1- 02461
1 02552

Sect. XX, 84.

July 28
4.35 a.m.
N. 46° 17' 00'
W. 56° 37' 00'

00 m.

0
10
25
40
50

32-24
.32-23
32-51
32-54
32-74

11-9

11-75

9-45

4-9

0-3

1-02449
1- 02452
1-02512
1- 02576
1 02629

1-02634
1-02661
1 02670
1-02699
1- 02720

Sect. XX, 85.

July 28
8.05 a.m.
N. 46° 02' 45'
W. 57° 09' 00'

492 in.

0

20

40

50

75

100

150

200

300

400

30-93
31-54
.32-56
33-39
33-26
33-42
34- 17
34-46
34-62
34-78

12-9
7-3
4-9
7-15
3-25
1-8
5-1
5-35
41
4-0

1-02329
1 02467
1-02578
1-02615
1-02650
1-02675
1- 02703
1 02725
1-02750
1-02763

1-02749

Sect. XX, 88.

July 28
5.45 p.m.
N. 45° 26' 00"
W. ,58° 34 '.30"

130 m.

0
25
40
50
75
100
125

30-27
31-34
31-68
31-86
32-15
32-50
3304

13-9
4-25
1-2
1-7
0-2
0-15
0-55

1-022.58
1-02487
1-02.539
1 02551
1- 02582
1 02610
1-02652

400

DEPARTMENT OF THE NATAL SERVICE

Table Id. — Salinity, Temperature and Density of the water on the Nova Scotian
and Newfoundland banks during the summer of 1915 — Concluded.

C. G. S. "ACADIA."

Station, time,
position and depth.

g

o.

o

Q

Salinity

d

E

Density

Station, time,
position and depth.

E

D.

Q

Salinity

d
E

Density

Sect. XX, 89.

July 28
8. .3.5 p.m.
N. 45° 16' 00"
W. .59° 04' 00'

130 m.

0
25
50

75
100
125

»/oo

30-52

30-90

31-92

.32-13

32 13

.32-24

13-95
9-1
0-75
015
0-15
0-05

1-02276
1-02.391
1-02561
1-02581
1-02581
1-02.590

Stat. 91. July 29

12.30 p.m.

Canso Strait,
off Hawkeshurv
50 m.

0
10
20
30
45

Voo

29 07

29-21

29-14

29-14

29-14

12-05

120

11-7

11-5

11-45

1- 02201
1-02212
1- 02213
1-02216
1-02217

CAXAUIAX FISHERIES EXl'EDITION, 191-1-15

401

Table le. — Salinity, Temperature luul Density of the water along the Coast
from Halifax to Newfoundland (Cabot strait) during the autumn of 1915.

C. G. S. "ACADIA. "

Station, time,

c

C

i'tation, time.

s

C

~

Salinity

d

Density

■£

Salinity

d

Density

position and dopth.

a.
C

position and depth.

a
Q

S

Voo

o

Voo

°

Stat. 92. Nov. 14

0

30-40

8-2

1 02366

Sect. XXI, 95.

0

30-52

7-75

1-02381

5.45—6.45 p.m.

Nov. 15

N. 44° 2.3' 00'

10

.30-41

8-4

1- 02364

6.45—7.25 a.m.

10

30-52

7-85

1-02.380

W. 62° 54' .30"

20

30-42

8-4

1- 02364

N. 44° .50' 00"

25

30-56

7-9

1 02,382

158 m.

W. 61° 03' 00"

30

30-43

8-4

1-02365

90 m.

40

31-86

5-35

1 02518

40

30-77

8-3

1-02397

50

32-11

3-65

1- 02555

50

31-60

6-85

1-02480

60

32-34

2-65

1 02.581

60
75

31-88
32-21

5-3
3-3

1-02519
1-02566

75

32-47

1-85

1-02598

90

32-53

2-2

1-02599

Sect. XXI, 96.

Nov. 15

0

30-61

6-95

1- 02399

110

32-84

1-9

1 02628

10..50— 11.10 a.m.

10

.30-63

7-2

1-02.398

N . 4.5° 1 1 ' 00"

25

30-72

7-3

1 - 02404

w! 60° 29' 00"

Sect. XXI, 93.

0

31-73

9-15

1 02446

40

30-86

7-3

1-02415

Nov. 14

75 m.

10.00—10.50 p.m.

10

31-74

9-3

1 02444

50

.32 16

3-5

1 02.560

N. 44° 09' 00'
\V. 62° 13' 00'

25

31-72

9-3

1- 02448

60

.32-41

1-95

1-02.588

40

31-74

9-3

1-02444

175 m.

Sect. XXI, 97.

0

30-42

6-4

1-02.391

50

32-86

5-2

1-02598

Nov. 15

2.45— 3.15 p.m.

10

30-44

6-7

1- 02.391

60

33- 12

4-15

1-02629

N. 45° 32' 00"

25

30-54

6-65

1-02400

75

33-24

3-9

1-02643

W. 59° 53' 00"

40

30-61

6-6

1-02404

100

33-60

4-85

1-02661

190 m.

50

30-67

61

1-02415

120

33-91

5-95

1-02672

60

31-23

5-75

1-024M

160

34-39

7-4

1-02691

75
100

31-96
32-62

4-5
1-6

1- 02535

1-02612

Sect. XXI, 94.

0

*31-05

8-4

1-02414

Nov. 15

125

33-03

0-9

1- 02649

2.40— 3.20 a.m.

10

32 14

9-2

1-02488

N. 44° 30' 00'

150

33-21

0-8

1 02664

W. 61° 39' 00"

25

31-55

9-85

1-02430

172 m.

40
50

31-03
30-95

8-9
8-75

1-02405
1-02402

175

33-23

0-8

1-02666

Sect. XXI, 98.

0

.30-61

615

1- 02409

60

32-97

5-55

1 02602

Nov. 15

6.50— 7.20 p.m.

10

30-96

6-3

1- 024.35

75

33-27

4-55

1-02637

N. 45° 54' 00'

25

30-97

6-3

1-02436

100

33-60

4-6

1-02664

W. 59° 17' 00"

40

3100

6-3

1-024.39

150

34-04

6-1

1-02680

83 m.

• Some errors in the labelling of the water samples must have occuired at this station in a depth of
o to 50 m. (see p. . .).

402

DEPARTMENT OF THE NAVAL SERVICE

Table le. — Salinity, Temperature and Density of the water along the Coats
from Halifax to Newfoundland (Cabot Strait) during the autumn of 1915 —

Continued.

C. G. S. "ACADIA."

Station, time,

S

d

Station, time.

s

U

^

Salinity

d

Density

43

Salinity

d

Density

position and depth.

a

a

c

position and depth.

&

Z
H

Voo

o

Voo

o

Sect. XXI, 98— Con.

50

31-21

5-65

1-02463

Sect. XXII &
XXIII, 102.

0

3211

4-45

1- 02546

60

31-74

4-5

1-02517

Nov. 23

5 a.m.

25

32-14

3-8

1-02556

75

32- 15

3-2

1-02562

N. 47° 26' 00"

50

32-31

3-45

1-02572

w! 57° 54' 00"

Sect. XXII, 99.

0

29-97

7-45

1-02343

75

32-60

1-8

1-02609

Nov. 15

231 m.

10.15 p.m.

10

30 06

7-5

1-02348

100

32-85

0-65

1-02636

N. 46° 17' 00"

25

30 09

7-5

1-02351

110

33-035

0-3

1-02653

W. 59° 33' 00"

40

30- 11

7-45

1-02354

125

33-07

0-2

1 02656

73 m.

50

30-16

7-4

1-02358

135

33- 17

0-65

1-02662

60

30-32

7-35

1-02372

150
200

33-21
33-61

0-5
1-95

1-02665

1-02688

Sect. XXII, 100.

Nov. 23

0

32-24

4-8

1 02.553

1 p.m.

25

32-15

4-65

1-02548

N. 46° 39' 00"

Sect. XXIII, 103.

0

32-11

4-85

1-02542

W. 58° 52' 00"

50

32-23

4-7

1-02554

Nov. 23

1.45 a.m.

25

32-13

4-75

1- 02545

Over 400 m.

75

32-28

4-45

1-02559

N. 47° 24' 00"

W. 58° 28' 00"

50

32-23

3-35

1-02557

100

32-85

0-75

1-02636

185 m.

75

32-77

1-35

1-02626

125

33-12

0-0

1-02661

110

32-85

0-65

1-02636

150

33-40

0-65

1-02681

125

32-945

0-25

1- 02646

200

33-86

2-8

1- 02701

150

33-12

01

1-02660

300

34-42

4-2

1- 02732

175

33-51

1-35

1-02685

400

34-70

3-95

1- 02748

Sect. XXII, 101.

0

32-20

4-9

1-02549

Sect. XXIII, 104.

0

32-205

4-55

1- 02553

Nov. 23

Nov. 22

9 a.m.

25

32-20

5-0

1-02548

10.35— 11.15 p.m.

25

32-20

4-5

1-02553

N. 47° 03' 00"

50

32-38

4-55

1-02569

N. 47° 21' 30"

50

32-48

2-95

1-02590

W. 58° 24' 00"

W. 59° 08' 30"

75

32-94

0-6

1-02643

75

32-70

1-5

1-02618

Over 400 m.

Over 400 m.

100

.32-98

0-3

1-02648

100

32-87

0-5

1-02638

125

33-21

005

1-02668

125

33-14

0-05

1-02663

150

33-51

0-35

1-02691

150

33-37

0-2

1-02680

200

34-06

3-4

1-02712

200

33-77

2-75

1-02694

300

34-61

4-2

1- 02749

300

34-45

4-2

1- 02735

400

34-80

4-1

1- 02765

400

34-74

4-0

1-02758

CANADIAN FISHERIES EXPEDITION, 191Jrl5

403

Table le. — Salinity, Temperature and Density of the water along the Coast
from Halifax to Newfoundland (Cabot Strait) during the autumn of 1915 —

Concluded.

C. G. S. "ACADIA."

Station, time,

s

d

Station, time,

S

O

ji

Salinity

a.

Density

jz

Salinity

2-

Density

position and depth.

Q

S

po.sition and depth.

Dep

1 Ten

Vuo

°

Sect. XXIII, 106—

Voo

»

Sect. XXIII, 10.1.

0

32- 15

5-6

1-02537

Con.

100

33-06

0-75

1 02652

Nov. 22

7.50— 8.30 p.m.

25

32- 10

5-55

1-02533

110

33-13

0-3

1- 02660

N. 47° 06' 00"

50

32 10

5-4

l-02.');55

125

32-27

3 05

1-02573

W. 59° 28' 30"

75

32-565

2-65

1-02599

150

31-34

4-65

1-02484

Over 400 m.

100

32-78

11

1- 02628

200

32-12

4-15

1- 02550

125

32-95

0-35

1- 02645

225

32-385

2-2

1 02571

150

33-33

0-8

1-02674

200

33-96

2-95

1 02708

Sect. XXIII, 107.
Nov. 22

0

30-28

5-95

1.02387

300

34-59

4-3

1-02745

3 p.m.

10

30-27

5-8

1-02389

400

34-785

4-25

1-02761

N. 46° 40' 00"
W. 60° 01' 00"

25

30-30

5-75

1-02390

128 m.

40

30-31

5-7

1-02391

Sect. XXIII, 106.

0

30-70

51

1-02428

50

30-44

5-35

1-02406

Nov. 22

5— 5.40 p.m.

25

31-89

4-7

1-02527

60

30-71

4-85

1-02431

N. 46° 51' 00"

50

32-21

4-55

1-02553

75

31-17

4-3

1- 02474

W. 59° 47' 00"

75

32-65

2-9

1- 02604

100

32-65

1-9

1- 02612

235 m.

90

33-00

0-05

1-02651

125

33-17

1-5

1-02656

6551— 29a

General Map

of
Area invesrigated

^Princess* Sect. l-ni,X-M
>Acad/a« SecfE-IX-EIIl-XZ.
>i>J5» Sect ET

-Read "C. Breton slaiid " for "Bii-tuD I, ' and ■•Sambro' for "Sabro". Also "Acadia Sect. V-IX, XIII-XX" for "Acadia Sect. V-IX-XIII-XX

Summer cruises.
Salinily

29iK.; ^1 Coastal water

Intermediate water
Bank water
Slope water
Atlantic water

Temperature

53 -

ATA.-HM. Xll. read "C. l!.Hi». I.l»i

n Islami". S.-Lt-XIV

CANADIAN FISHERIES EXPEDITION, 1914-15.

BIOLOGY OF ATLANTIC WATERS OF CANADA.

SOME QUANTITATIVE AND QUALIFATIVE PLANKTON STUDIES
OF THE EASTERN CANADIAN PLANKTON.

BY

A. G. HUNTSMAN, B.A., M.B.,

University of Toronto, Curator of the Atlantic Biological Station, St. Andrews,

New Brunswick.

1. — Introduction.

2.— Quantity of Plankton.

3. — A special Study of the Canadian Chaetogiiaths, their distribution, etc., in the
waters of the Eastern Coast.

6551—30

CANADIAN FISHERIES EXPEDITION, 191J,-io 405

CANADIAN FISHERIES EXPEDITION, 1914-1915.

BIOLOGY OF ATLANTIC WATERS OF CANADA.

SOME QUANTITATIVE AND QUALITATIVE PLANKTON STUDIES OF THE
EASTERN CANADIAN PLANKTON.

BY

A. G. HUNTSMAN, B.A., M.B., Etc.,

University of Toronto, Curator of the Atlantic Biological Station, St. Andrews,

New Brunswick.

1 . — Introduction.
2. — Quantity of Plankton.

S. — A special Study of the Canadian Chaetognaths, their distribution, et<:-., in the
'waters of the Eastern Coast.

PREFATORY NOTE.

By Prof. E. E. Prince^ Dominion Commissioner of Fisheries, and Chairman of the

Biological Board of Canada.

A note of explanation api>ears desirable respecting the series of papers by Dr.
Huntsman which are here brought together. They are separate reports upon his work
during the season of 1915 (under Dr. Hjort's Canadian Fisheries Expedition) ; but, in
subject and treatment, they form practically one research, the first short paper being of
the nature of an introduction ; the second paper has a general character, the quantitative
phase being emphasized in it, and demonstrating that in colder and deeper water the
plankton content is more abundant than in warmer, more superficial, strata, while the
plankton as a whole seeks during the night a deeper level than during the day. The
third paper embodies a detailed study of the distribution of Sagitta, or rather of the
Chaetognaths, of which Dr. Huntsman determines ten species in our eastern coastal
waters, seven species of Sagitta, and one species each of Pterosagitta, Eul-rohnia, and
Khronitta. These delicate, actively swimming creatures, of a glassy translucency and
needlelike in form, are typical pelagic forms, at one time included amongst sea-worms;
but now^ regarded as an aberrant group. They proved to be very abundant, and must
form an important element of food for fishes, especially in the younger stages of the
latter. These Chaetognaths vary in length from half an inch to tmo inches (50mm.) in
length, and Dr. Huntsman's elaborate study is of special interest and importance, and
illustrated by twelve figures, four of them being drawings of the creatures themselves,
and eight of them charts showing the details of their distribution in the sea.

6551—30*

406 DEPARTMENT OF THE NAVAL SERVICE

INTRODUCTION.

By A. G. Huntsman, B.A., M.B., University of Toronto, Curator of the Atlantic
Biological Station, St. Andrews, N.B.

In undertaking a study of certain groups of animals from the plankton, as pro-
posed by Dr. Johan Hjort, I have been obliged to limit it to certain forms that could
be identified with reasonable ease. Not having a special knowledge of these groups, it
has been necessary for me to repeatedly alter the scope and method of work during the
progress of the investigation. This has resulted in a lack of uniformity in the records
that would have been avoided if it had been possible to formulate a definite plan at tlie
beginning.

This collection of plankton has been of the greatest interest, not only because it
came from localities representative of the greater part of our Atlantic waters and
permitted a survey of the whole region, but also because it came from waters of such
diverse nature. It has afforded an unequalled opportunity for an introduction to, if
not a solution of, the problem of the factors that are concerned in the distribution of
our planktonic species. The subject has been considered from that standpoint, namely,
to determine, if possible, the distribution, both vertical and horizontal, and the rela-
tive abundance, of each species.

The time was too short for taking many closing-net hauls, which are so essential
in determining the vertical distribution. It was also unavoidable that the hauls were
not perfectly reliable for quantitative comparison of the regions covered. Some of the
factors to which this was due are: the well-known irregularity in the local distribu-
tion of species (their occurrence in streaks or shoals which may be taken or missed
in successive hauls at the same locality) ; the hauls not having been taken uniformly
either from the bottom, from a certain depth, or to the surface (at certain stations no
vertical hauls were made) ; the hauls not having been always strictly vertical owing
to the drifting of the ship before the wind; the variations in the coeflicient of filtration
of the net, depending upon its condition, the character of the plankton and the rate
of hauling; the individual factor, the hauls having been taken by different persons;
occasionally incomplete or faulty preservation; the difficulty in recognizing small
specimens in large quantities of plankton; the unsuitability of the method of capture
for large species (capturing too few) and for small species (their passage through or
retention in the net depending upon the other elements in the plankton).

For these reasons the results as to distribution must be accepted with reserve and
considered as tentative merely. It has been necessary, however, to take the results as
they stand and, notwithstanding the large element of doubt, to put forth general views
which future investigation may either confirm or refute. Where possible, account has
been taken of these factors. Knowing the irregularities in the method of obtaining the
plankton, I have been frequently astonished at the apparent completeness of the
picture presented in the distribution of many of the species.

The charts of distribution have been made graphic by lining in the supposed
areas of distribution, the positions of the stations from which data were obtained
being indicated by circles. This method is objectionable in that it shows perhaps more
than the facts warrant, but, since all the data are published, false impressions may be
corrected by reference to them.

In some instances the hauls that were taken were not of the proper kind to show
definitely the presence or the absence of a species. Such stations have not been con-
sidered in plotting the charts, although many of them have been indicated on the
charts. For example, no vertical hauls were taken at Acadia Stations 10, 18-2'2, 27,
33, 43, 61, 77, and 90; the vertical hauls of the cruises of the Princess were not deep

CA^'ADIAN FISHERIES EXPEniTIOX, lOl'rto 407

enough to explore the peculiar bottom water of the deeper portions of the gulf. It has
not been thought necessary to refer in every instance to these evident imperfections
in the material.

The tow hauls arc the most unreliable, owing to lack of information in the records
as to the manner in which thej' were taken. The depths given are in most instances
merely presumptions from the scanty data available. The tow hauls were taken in a
great variety of ways.

There has been a possibility of considerable error arising in counting the speci-
mens, for, owing to the large amount of plankton and the short time available for the
work, it was necessary in many cases to take only a portion of the catch for examina-
tion and for the determination of the number of individuals. A varying portion was
taken, depending largely upon the quantity of the plankton and the ninnlu'l- and the
range of size of each species. The figures indicate the manner in which the deter-
mination was made: 15x10 meaning that 15 individuals were counted in approximately
one-tenth of the entire haul. With many of the tow hauls arbitrary signs have been
used to indicate roughly the relative number of individuals : x meaning that the species
occurred or that only a few specimens could be seen; xx meaning that there were more
numerous; + meaning that there were many; and ++ meaning that there were very
many.

There is also a doubt as to proper identification when large numbers are examined
rapidly. Errors from these causes have been detected and corrected in a number of
instances. Naturally, the larger the individuals the less likelihood is there for such
errors to arise.

2.— ON THE QUANTITY OF PLANKTON OBTAINED AT ONE HFNDRED
AND SEVENTY-NINE STATIONS DURING THE CANADIAN FISH-
ERIES EXPEDITION, 1915.

(By A. G. Huntsman, B.A., M.B., Curator of the Atlantic Biological
Station, St. Andrews, New Brunswick.)

At Dr. Hjort's request, I have determined roughly the amount of plankton taken
in the various hauls during the cruises of C.G.S. Acadia, C.G.S. Princess, and C.G.S.
No. 33. For a number of reasons the data are far from being accurate. The plankton
was not measured at the time it was obtained. In most cases all of the plankton was
preserved, but at times only a portion was retained and the rest thrown away. In
some of these cases (but not all) an estimate was made of the total amount at the time
it iwas taken. In other cases the plankton was partially sorted or a portion taken out
before being measured. As a result, some of the larger quantities should be still larger,
but the smaller quantities are approximately correct.

The table given below is self-explanatory, but some comment may be advisable.
Under " hour " are given the times of commencement and finish of the station as far
as the records were kept. When only one time is given, it is the time at which the
station was begun. The depth of water is given in metres. When no sounding in
metres was made, the sounding in fathoms has been converted into metres for
uniformity.

The hauls of plankton were made in three ways: (1) Vertical hauls (vert.) in
which the net was lorwered to a certain depth and then hauled to the surface; (2)
vertical closing hauls (vert, clos.), similar but closed some distance before the surface
was reached; and (3) toiv hauls (tow), in which the net was towed at a variable dist-
ance from the surface. The vertical hauls were not always vertical owing to the
drifting of the ships, fwhich in some cases was considerable. The numbers given for the
depths of the hauls indicate the amount of wire out, which was occasionally more than
the actual depth at the station. In Acadia stations 44 to 91 the vertical hauls were

408

DEPARTMENT OF THE NAVAL- SERVICE

made in fathoms. These have been converted to round numbers in metres. No time
has been given for the tow hauls. The records are not complete in this respect. In
many of these hauls the net was towed by the drifting of the ship before the wind.
Sometimes it was part drift and part steam towing. The rate at which the net was
to\^ed varied within such wide limits that the time could not well be used for purposes
of comparison. This does not apply to the tows made by C.G.S. No. S3. The letter
"c*' (circa) before the depth indicates that the depth has been presumed only.

With two exceptions all the hauls were made with a net having a mouth with a
diameter of one metre and made of silk bolting clpth with from fifteen to sixteen meshes
to the centimetre. Certain hauls made at Princess stations 1 and 2 were made with a
net of finer mesh (gear 20).

When two hauls were made at the same depth at the same station, these have been
distinguished by the Eoman numerals I and II.

The plankton was measured after settling in the bottles in which it was preserved.
Similar bottles were graduated and the amount of plankton determined by comparing
the bottle containing the plankton with the graduated bottle of the same kind. This
was a quick but rough method of determining the amount.

The measurements confirm the observations made during the cruises that: (1)
there is more plankton in colder water, (2) there is more plankton where the water is
deeper, and (3) the plankton as a whole is at a deeper level during the day.

PLANKTON.— HAULS AND QUANTITY.
C. G. S. "Acadia."

No.

of

Station .

10

Date.

May 29.

May 29.

May 29.

May 30.

May 30.

May 30.

May 30.

May 30.

May 30.

Hour.

11.05a.m.-12.0.5p.m.
2.30-4..30 p.m

7.30 p. m

1.00-2..30a.m

5.30-6.30 a.m

10.15-11.15 a. m

12. .55 p.m

5.00-6.00 p.m

7.15-9.00 p.m

Depth

(metres).

60

99-144

171

45

108
£0

104

732

Depth of Haul (metres).

50- 25
20- 0
100- 50
30- 0

0

150-100

80- 40

30- 0

60- 0

0
40- 0

0

0
50(?)- 0

0
25- 0

0

0

(vert, elos.)

(vert.)

(vert, clos.)

(vert.)

(tow)

(vert, elos.)
(vert, clos.)

(vert.)

(vert.)

(tow)

(vert.)

(tow)

(tow)

(vert.)

(tow)

(vert.)

(tow)

(tow)

Quantity

(in c.c.)

15

2

35

10

30

70

15

25

25

170

35

35

5

5

25

5

20

800

CANADIAN FISHERIES fSXi^DDITION, 19U-15

409

PLANKTON.— HAULS AND QUANTITY— rofi/inued.
C. G. S. "Acadia" — ConlinueJ.

12

13

14

15

16

17

18
19
20
21
22
23

24

25

26

27
28

29

30

June 1... 9.00-10.15 a. in I over 2,000

May 30-31. 10.50 p. in. -12. 50 a.m.

May 31.

May 31.

May 31.

May 31.

4.30-6.35a.m...

8.45-9.45 a.m..
12.55-2.30 p.m.

7.1.V9.00p.m..

June 1 . . . . 1.45-3.15 a.m.

over 2,000

over 2,000

over 2,000
over 2,000

over 2.000

over 2.000

June 1 .

June 1 .

June 2.

June 2 .

June 2 .

June 2 .

4.30 p. m

8.15-10.00 p.m.

1.00 a. m

3.45-4.45 a.m. .
7.25-7.50 a.m..
10.35 a.m

June 2... 2.1.5-3.00 p.m.

June 2 .

June 2.

June 3 .

June 3 .

June 3 .

5.40-6.30 p.m.

over 2,000
over 2,000
90
115

118

122

10.00-11.15 p. in ■■ over 400

2.10-3.30 a.m.
6.15-7.45 a.m.

10.55 a.m. -12 noon.

June 3.. 3.00-3.45 p

over 400
over 400

57

126

70- 0
0

100- 0

0

70- 0

200- 0
0

100- 0
0

200- 0
0

200- 0
0
0
0
0
0
0
70- 0
0

100- 0
0

120- 0

10(?)-0

100- 0
0
0

100- 25

0

55- 0

0

120(?)-0

0

vert.)

tow)

vert.)

tow)

vert.)

vert.)

tow)

vert.)

tow)

vert.)

tow)

vert.)

tow)

tow)

tow)

tow)

tow)

tow)

vert.)

tow)

vert.)

tow)

vert.)

tow)

vert.)

tow)

tow)

vert, clos.)

tow)

vert.)

tow) ■. . .

vert.)

tow)

70

800

70

2.50

30

70

5

175

550

90

160

50

20

CO

100

45

45

25

10

7

25

25

60

15

55

400

400

05

80

10

5

25

410

DEPARTMENT OF THE NAVAL SERVICE

PLANKTON.— HAULS AND QVANTITY—Continued.
C. G. S. "Acadia." — Continued.

No.

of

Station,

Date.

Hour.

Depth
(metres).

Depth of Haul (metres).

Quantity
(in c.c.)

31

32

33
34

35

36

37

39

40

41

42

43
44

June 3. . .

June 3-4 .

June 4 . . .

June 4. . .

June 4 . . .

June 4 .. .

July 21...

July 21 . . .

July 21...

July 22...

July 22...

July 22...

July 22...

July 22...

7..30-8.30 p.m

11.15 p.m.-12.15a.m

3.50-4.50 a.m

7.45-8.45 a.m

11.55 a.m. -12. 55 p.m

3.,30-4..30 p.m

5.00 p.m

8.00 p.m

11.00 p.m

2.00 a.m

5.30-6.30 a.m

9.00 a.m

11.50 a.m

3.00 p.m

82

153

70
e. 360

c. 450

226

62

170

95

1.34

360

over 1 ,000

over 1,000
over 1 ,000

75(?)-0

0
100- 25

0

0
100- 0

0
125- 25

0
100- 15

0
60- 20
60- 0
20- 0

0
150- 0
100- 0

0

100- 0

25- ?

0
125- 0
125- 0

0
200- 0
100- 0

0
200- 0

0

0
270- 0

0

vert.)

tow)

vert, clos.)

tow)

tow)

vert.)

tow)

vert, clos.)

tow)

vert, clos.)

tow)

vert, clos.)

vert.)

vert.)

tow)

vert.)

vert.)

tow)

vert.)

vert . )

tow)

vert.) I....
vert.) II...

tow)

vert.)

vert.)

tow)

vert.)

tow)

tow)

vert.)

tow)

70

75

125

115

?

90
32
70
20
20
30
15
15

1 (?)
100

60
75
110
50
50
75
25
25
12
5(?)

2 (?)
10 (?)

5

5

5
25
40

C4X4DJ.4.Y FISHERIES EXPEDITIOX, 191.'rl5

411

PLANKTOX.— HAULS AND QV A^i TIT \— Continued.
C. G. S. "Acadia" — Continued.

No.

of

Station.

Date.

Depth
(metres).

Depth of Haul (metres).

Quantity
(in c.c.)

45

46

47

48

49

50

51

July 22.

.July 23.

July 23.

July 23.

July 23.

July 23.

July 23.

52 Julv 24 .

53

54

55

56

July 24.

July 24.

July 24 .

July 24.

8.10 p.m.

1.00 a.m.

6.30 a.m.

11.00a.m.

3.35 p.m.

7.30 p.m.

10.25 p.m.

1.45 a.m.

4.45 a.m.

7.30 a.m.

10.25 p.m.

2.15 p.m.

over 1,000

over 1 ,000

140

248

126

151

131

95

over 1,000

over 1,000

over 1,000

270- 0 (vert.) 50

90- 0 (vert.) 5

0 (tow) 50

270- 0 (vert.) . 130

0 (tow) 25

125- 0 (vert.) 25

90- 0 (vert.) 15

0 (tow) 10

70-2 0 (vert.) 70

4.5- 0 (vert.) 2

0 (tow) 25

125- 0 (vert.) 1 35

125- 0 (vert.) II 35

0 (tow) 100

14.5- 55 (vert, clos.) 80

145- 0 (vert.) 55

55- 0 (vert.) 25

0 (tow) 45

125- 55 (vert, clos.) 60

125- 0 (vert.) 60

0 (tow) 100

90- 0 (vert.) 1 40

90- 0 (vert.) II 45

0 (tow) 25

90- 0 (vert.) 40

0 (tow) 120

270- 0 (vert.) 10

125- 0 (,vert.) 5

0 (tow) 5

270- 0 (vert.) 15

90- 0 (vert.) 5

0 (tow) 5

375-250 (vert, clos.) i 15

250- 0 (vert.) ' 10

412

DEPARTMENT OF THE NAVAL SERVICE

PLANKTON.— HAULS AND QUANTITY— Con^mwed.
C. G. S. "Acadia" — Continued.

No.

of

Station.

57

58

59

60

61

63

66

67
67

68

Date.

July 24.

July 24.

July 25.

July 25.

July 25 .

July 25.

July 25.

July 25.

July 25.

July 26.

July 26.

July 26.

Hour.

7.18 p.m.

10.35 p.m.

12.00 a.m., . .

6.53 a.m

7.30 a. m

10.05 a.m....

11.55 p.m. . . .
5.15 p. in

7.55-8.30 p.m

11.55-12.30 a.m.
11.55-12.30 a.m.

3.55 a.m.

Depth

(metres).

over 1,000

187

45

99

72
61

53

90

63

198
198

53

Depth of Haul (metres).

270- 90

90- 0

0

180- 55

155- 0

55- 0

0

45- 0

0

90- 0

0

0

55- 0

55- 0

0

55- 0

0

110- 0

90- 0

0

55- 0

55- 0

0

190- 0

90- 0

0

45- 0

45- 0

0

5- 0

c. 20- 10

(vert. elos.).

(vert.)

(tow)

(vert. elos.).

(vert.)

(vert.)

(tow)

(vert.)

(tow)

(vert.)

(tow)

(tow)

(vert.) I....
(vert.) II...

(tow)

(vert.)

(tow)

(vert.)

(vert.)

(tow)

(vert.) II...
(vert.) II...

(tow)

(vert.)

(vert.)

(tow)

(vert.) I

(vert.) II...

(tow)

(tow)

(tow)

Quantity

(in c.c.)

50
35
25
30
50
25
10
25

500
65
20
45
40
75
over 65
60
50
10
10
25
15
12

150

150
50

230

5

8

50

20

100

CANADIAN FISHERIES EXITAJITION, 19Ulo

413

PLANKTON.— HAULS AND QVXSTITY— Continued.
C. G. S. "Acadia" — Continued.

Date.

Hour.

Depth

(metres).

Depth of Haul (.metres).

Quantity
(in r.c.)

.July 26.

•July 26

.July 26.

July 26.

.July 26.

July 27.

July 27.

July 27.

July 27.

July 27.

July 27.

July 28.

8.05 11. m.

11.40-1.00 p.m.

68

3.45 p.m.

7.00 p.m

10.55 p.m

2.45 a.m

7.25 a.m

12.05 p.m. . . .

3.40-4.15 p.m

7.20 p.m

10.00 p.m....

12.45 a.m

over 1,000
over 1 ,000
over 1,000
over 1,000

over 1,000

over 1,000
360

168

60
60

172

60- 0

60- 0

5- 0

c. 20- 10

325- 0

55- 0

c. 20- 10

325- 0

55- 0

c. 20- 10

325- 0

55- 0

c. 20- 10

325- 0

55- 0

e. 20- 10
270- 0

c. 20- 10

c. 20- 10

325- 0

55- 0

145- 0

55- 0

f. 20- 10
55- 0

0. 20- 10
55- 0
55- 0

c. 20- 10

160- 0

55-100

c. 20- 10

(vert.) I..
(vert.) II.

(tow)

(tow)

(vert.)....

(vert.)

(tow)

(vert.)

(vert.) —

(tow)

(vert.)..,..

(vert.)

(tow)

(vert.) —

(vert.)

(tow)

(vert.)

(tow)

(tow)

(vert.) —
(vert.) —
(vert.) —
(vert.) —

(tow)

(vert.)

(tow)

(vert.) I.,
(vert.) II.

(tow)

(vert.)

(vert.) —
(tow)

55

20

5

1(?)
10

5

1 (?)

4
20

2

5
10

2
15
25

5
50
40

20

35

45

25

50+

25

85

15

20

+ c. 25.000
(Aurelia)
70

45
400

414

DEPARTMENT OF THE NAYAL SERVICE

PLANKTON— HAULS AND QVANTITY— Continued.
C. G. S. "Acadia" — Concluded.

No.

of

Station.

Date.

Hour.

Depth

(metres).

Depth of Haul (metres).

Quantity
(in c.c.)

84

85

86

87

90
91

July 28.

July 28.

July 28.

July 28.

July 28.

July 28.

July 29.
July 29.

4.35 a.m.

8.05 a.m.

11.10a.m.-12.30p.m.

2.15 p.m.

5.45 p.m.

8.35 p.m.

c. 2.00 a.m..
c. 12.30 p.m.

60

over 400

over 400

331

130

132

c. 60
c. 45

55- 0

55- 0

c. 20- 10

270- 0

55- 0

c. 20- 10

270- 0

55- 0

r. 20- 10

290- 0

55- 0

c. 20- 10

110- 0

55- 0

c. 20- 10

115- 0

55- 0

c. 20- 10

c. 20- 10

45- 0

(vert.) I.
(vert.) II
(tow)....
(vert.)...
(vert.)...

(tow)

(vert.).. .
(vert.)...

(tow)

(vert.)...
(vert.)...

(tow)

(vert.). . .
(vert.). . .

(tow)

(vert.) —
(vert.). . .

(tow)

(tow)

(vert.)...

35

50
230

65

20
150

60

40

60

50

20
125

15
5

20

80

55
235
200+
5

C. G. S. "Princess."

May 11.

May 11.

June 9 .

June 9.
June 10.

June 10.

9.00 a.m.

3.20^.30 p.m.

11.00 a. m.-12.00 noon.

5.10 p. m

8.50-9.35 a.m.

12.30 p.m.

45

20

32

57

?

20- 0 (vert.)

0 (tow).

20- 0 (vert.)

30- 0 (vert.)

0 (tow).

60- 0 (vert.)

0 (tow).

100
10 (gear 20)

90
10 (gear 20)
5
50
15
25

120+
20
50

CANADIAX FISHERIES EXPEDITION, 1914-15

415

PLANKTON'.— HAULS AND QUANTITY— Conhnwed.
C. G. S. "Princess" — Continued.

No.

of

Station.

Date.

Hour.

Depth

(metres).

Depth of Haul (metres).

Quantity
(in CO.)

June 10.

June 10

10

12

15

16

17

18

19

20

21

Tune 11

June 11.

June 1 1 .

Juno 11 .

June 1 1 .
June 1 1 .

June 12.

June 12 .

June 12 .

June 12.

June 13.

June 13.

June 13 .

3.40-4..30p.m.

8.1.5-10.00 p.m.

12.1.5-1.00 a.m.

7.00 a.m.

9..30a.m.

12.30-1.30 p.m.

4.00 p.m.
7.00 p.m.

9.00-10.00 a.m.

1.15 p.m.

4.30 p.m.

7.30 p.m.

2.45 a.m.

6.00 a.m.

80

80

over 200

over 200

48

135

9.45 a.m.

over 200
39

90

over 250

130

63

81

over 200

over 400

80- 0

0
80- 0
40- 0

0

0

100- 0

80- 0

0
100- 0

0
50- 0

0
100- 0

0

100- 0

35- 0

0
80- 0

0
100- 0
100- 0

0
100- 0
100- 0

0
50- 0

0
80- 0

0
100- 0

0
100- 0

0

vert.)

tow)

vert.)

vert.) —
tow.). . . .

tow)

vert.) —

vert.)

tow)

vert.) —

tow)

vert.)

tow)

vert.) —

tow)

vert.) —
vert.) —

tow)

vert.) —

tow)

vert.) I..
vert.) II.

tow)

vert.) I..
vert.) II.

tow)

vert.)

tow)

vert.)

tow)

vert.)

tow)

vert.) —
tow)

10

15
90
90
50
180

(gear 20)
55
50
50
50+
45
20
20
30
55
10

3

5
25
15
40
45
20
35
35
40
15

2

30
50
50
65
60
15

416

DEPARTMENT OF THE NATAL SERVICE

PLANKTON— HAULS AND QUANTITY— ConhnMed.
C. G. S. "Princess" — Continued.

No.

of

Station.

22
23
24

25

26

27

28

29

30

31

32

33

June 13.
June 13 .
June 15 .

June 15.

Date.

June 15.

Aug. 3.

Aug. 3^ .

Aug. i.

Aug. 4 .

Aug. 4.

Aug. 4.

Aug. 4

Hour.

1.30 p. m

4.00 p.m

7.30-7.55 a.m

11.00 a.m. -12 noon

3.00-4.00 p.m.

5.30-6.30 p.m.

11.45 p.m. -1.30 a.m.

6,10-7.15 a.m.

10.15-11.05 a.m.

1.35-2.40 p.m.

4.55-5.50 p.m.

8.5.5-9.50 p.m.

Depth

(metres).

52

115

40

63

39

23

19

32

65

87

78

Depth of Haul (metres).

Quantity
(in c.c.)

50- 0

100- 0

35- 0

35- 0

0
60- 25
60- 25
60- 0
60- 0

0
40- 0
40- 0

0
20- 0
20- 0

20- 0
20- 0
20- 0

20- 0

c. 20- 10

60- 0

30- 0

c. 20- 10

60- 0

30- 0

c. 40- 0

80- 0

30- 0

c. 40- 0

80- 0

30- 0

c. 40- 0

vert.)

vert.)

vert.) I

vert.) II

tow)

vert, clos.) I. .
vert, clos.) II.

vert.) I

vert.) II

tow)

vert.) I

vert.) II

tow)

vert.)

tow)

vert.) I. .
vert.) II.
tow)

vert.),
tow). .
vert.),
vert.),
tow) . .
vert.),
vert.),
tow). .
vert.),
vert.),
tow). .
vert.),
vert.),
tow)..

20
80

5

8
30

5
10
25
40
50

5
10
20

1

(plankton +

bottom

material)

(plankton +

bottom

material)

12

25

20

10
150

30
5

30

50

25
120

30

25
260

CAyADIAN FISHERIES EXPEDITION, 191'rlo

417

PLANKTON— HAULS AND QUANTITY— Con/inueJ.
C. G. S. "Princess" — Continued.

Aug. 4-5.

Aug. 5 .

Aug. 5.

Aug. 5 .

Aug. 5.

Aug. 5.

Aug. 5-6

.\ug. 6 .

Aug. 6.

Aug. 6.

Aug. 6 .

11.55 p.m. -2. 25 a.m.

4.40-6.35 a.m.

9.30-10.20 a.m.

12.45-1.35 p.m.

4.00-5.00 p.m.

7.00-8.35 p.m.

11.30 p.m. -12.25 a.m.

3.30-4.55 a.m.

7.25-8.00 a.m.

11.00 a. 111.-12 noon.

2.30-3.10 p.m.

Depth

(metres).

405

over 350

48

75

180

284

189

90

265

Depth of Haul (metres).

157

130-

30-

c. 40-

130-

30-

c. 40-

60-

c. 40-

80-

30-

C.40-

1.30-

40-

c. 40-

130-

40-

c. 40-

70-

30-

c. 40-

130-

30-

c. 40-

100-

30-

c. 40-

130-

130-

30-

30-

c. 40-

130-

30-

0 (vert.)....
0 (vert.)....

0 (tow)

0 (vert.)....
0 (vert.)....

0 (tow)

0 (vert.)...,

0 (tow)

0 (vert.)....
0 (vert.)...
0 (tow).....
0 (vert.)...
0 (vert.)...

0 (tow)

0 (vert.)...
0 (vert.)...

0 (tow)

0 (vert.)...
0 (vert.)...

0 (tow)

0 (vert.)...
0 (vert.)...

0 (tow)

0 (vert.)...
0 (vert.)...

0 (tow)

0 (vert.) I.
0 (vert.) II
0 (vert.) I.
0 (vert.) II
0 (tow)....
0 (vert.)...
0 (vert.)...

Quantity
(in c.c.)

45
10
1.50
20?
.30?
140
20
75
10

5
50
20

5
30
25

5
25
15
15
55
10

10

2

10

10

8

2

1

30

25

10

418

DEPARTMENT OF THE XAVAL SERVICE

PLANKTON.— HAULS AND QUANTITY— Continued.
C. G. S. "Princess" — Concluded.

No.

of
Station.

Date.

Hour.

Depth

(metres).

Depth of Haul (metres).

Quantity
(in e.c.)

45

46

47

49

50

Aug. 12.

Aug. 12.

Aug. 12.

Aug. 12.

Aug. 12.

Aug. 12-13.

2.05-.3.50a.m.

5.25-6.35 a.m.

8.35-10.00 a.m.

12.40-2.00 p.m.

6.25-7.05 p.m.

11.25 p.m.-12.20a.m.

375

over 400

over 400

171

52

130-

30-

c. 40-

130-

30-

c. 40-

130-

130-

30-

c. 40-

130-

30-

c. 40-

70-

30-

c. 40-

40-

40-

c. 40-

0 (vert.

0 (vert.

0 (vert.

0 (vert.

0 (vert.

0 (tow)

0 (vert.

0 (vert.

0 (vert.

0 (tow)

0 (vert.

0 (vert.

0 (tow)

0 (vert.

0 (vert.

0 (tow),

0 (vert.

0 (vert.

0 (tow).

35
20

300
20
15

210
15
10
3
30
30
20

130
40
15
70
10
10

100

CAXADIAX FISHFAilKs EX I' EDITION, IDl.'f-lo

419

PLANKTON.— HAULS AND QM A^TITX— Continued.
C. G. S. "No. 33".

6551-31

420

DEPART3IENT OF TEE XAYAL SERVICE

PLANKTON.— HAULS AND QUANTITY— ronY/nMcd.
C. G. S. No. "33" — Concluded.

No.

of

Station.

Date.

Hour.

Depth

(metres).

Depth of Haul (metres).

Time.

Quantity
(in c.c).

35

July 7....
July 8 . . . .
July 13...
July 26...
July 27....
Aug. 7....

.A.ug. 9...
Aug. 10...
Aug. 10...
Aug. 11...
Aug. 13...
Aug. 17. . . .
Aug. 17...
Aug. 18....
.\ug. 18....

11.00 a.m

25
60
38

?

?
110

210

50

275

•>

9
?

?
?

15- 6 (tow)

20- 8 (tow)

c. 9 (tow)

40- 0 (tow)

, 15- 0 (tow)

70- 34 (tow)

25- 5 (tow)

200- 0 (vert.)

? min

45 min

? min

? min

? min

I5 hours

1 2 hours

50

36
40

48

5.00 p.m

? p.m

5.00 p.m

110
95
90

49

54

57

5.00 p.m

9.15 a.m

3.15 p.m

11.10 a.m

12.50 p.m

?

145

2,000+

2,000+

75

58
59

c. 40- 0 (tow)

270- 0 (vert.)

20 min

50
130

62

30- 0 (tow)

8

64
67

68

9.30 a.m

7.00 p.m

4.00 a.m

2..30p.m

80- 20 (tow)

30- 0 (tow)

70- 20 (tow)

80 min

75 min

35 min

75+
8
350

69
70

100- 20 (tow)

8- 2 (tow)

45 min

75 min

320
100

BIOLOGICAL LAUNCH "Prince."

No.

of

Station .

Date.

Sept. 14.

Sept. 14.

Sept. 15.

Sept. lo.

Hour.

3.45 p.m.

4..30-5.00p.m.

10.00-11.00 a.m.

5.30 p.m.

Depth
(metres).

c. .38

c. 100

180

c. 35

Depth of Haul (metres)

c. 3.5- 0 (vert.) I.

c. 35- 0 (vert.) II

c. 20- 10 (tow)....

0 (tow)....

100- 0 (vert.)...

c. 4- 2 (tow)

180- 0 (vert.)...

20- 10 (tow)....

2- 0 (tow)....

c. 35- 0 (vert.)...

15- 5 (tow)

Quantity
in (c.c.).

18
12

230
40
30
20

220
40
25
10
10

C AX AD I AX FISHERIES EXI'EDITIOX, lOl-'rlo 421

3. A SPECIAL STUDY OF THE CAXADIAX CH.ETOGXATHS, THEIR
DISTRIBUTION, ETC., IN THE WATERS OF THE EASTERN COAST.

By A. G. IIuxTSMAX, B.A., M.B., University of Toronto.
, . (With 12 Figures.)

The transparent worm-like animals of this group were A'ery prominent in the
catches, sometimes forming more than half of the entire catch. In comparatively few
instances were they lacking. The method employed was therefore a suitable one for
studying their distribution, and they are as valuable as any group as an index of the
character and origin of the "water. They are free-living in all stages and therefore
independent of the presence of banks per se. Their distribution will depend upon
temperature, salinity, light, oxygen, currents, and food.

The measurements given are of the total length. In determining the tail per-
centage the tail fin was not included in the measurements. The number of jaws at
first increases and later may decrease with age.

KEY TO THE SPECIES.

Ai. Two pairs of lateral fins. (Sagitta.)

Bi. Fins (lateral) adjacent or connected.

Ci. Anterior fin not extending to ventral ganglion.

S. hjra. Rather soft and stout. Transparent. Fins with anterior end and inner zone
free from rays. 8-10-3 jaws. Tail percentage, 21-14. No collarette. Ovary
rodlike. Up to 38mm.
C2. Anterior fin extending to ganglion.

S. maxima. Rather soft and stout. Transparent. Fins with anterior end and inner
zone free from rays. 10-11-4 jaws. Tail percentage, 32-19. No collarette.
Ovary rodlike. Up to 87mm.
B2. Fins separated.

Di. Fins completely traversed by rays.

El. Anterior fin extending to ventral ganglion.

S. hipunciata. Stiff and slender. Rather opaque. 8-10-7 jaws. Tail percentage, 28-
21. Short collarette. Ovary rodlike. Up to 25mm.
E2. Anterior fin not exteeding to ventral ganglion.

S. elegans. Stiff and moderately slender. 8-13-8 jaws. Tail percentage, 27-10. Short
collarette. Ovary rodlike. Up to 52mm.

D2. Fins not completely traversed by rays (anterior end and inner zone free).
Fi. Anterior fin extending to ventral ganglion.

S. serratodentata. Stiff and slender. Rather opaque. 5-10 jaws, tips turned inwards
and inner edges serrate. Tail percentage, 32-20. Short collarette. Up to
24mm.

F2. Anterior fin not extending to ventral ganglion.
Gi. Anterior teeth few (3-5), long and diverging.

S. hexaptera. Stout. Transparent. 7-10-4 jaws. Tail percentage, 26-16. No collar-
ette. Ovary rodlike. Up to 70nam.

G2. Anterior teeth many (5-11), short and overlapping.

^. ejiflata. Soft and stout. Transparent. 7-10-7 jaws. Tail percentage, 23-14. Short
collarette. Ovary sausage-shaped. Up to 30 mm.

A2. One pair of lateral fins.

Hi. Lateral fins on tail only. Two rows of teeth on each side.
6551-31i

422 DEPARTMENT OF THE XAVAL SERVICE

Pterosagitta draco. Stiff. Rather opaque. Fins completely traversed by rays. 7-10-8
jaws. Tail percentage, 46-38. Collarette very thick and over whole of trunk.
Ovary rodlike. Up to llmm.

H2. Lateral fins on both trunk and tail. One row of teeth on each
side.
Ji. Fins extending- to ventral ganglion and largely without rays.

Eukrohnia hamata. Stiff and moderately slender, 8-11-9 jaws. Tail percentage, 22-32.
No collarette. Up to 43mm.

J2. Fins well behind ventral ganglion, with small inner zone free
from rays.

Krohnitta suhtilis. Stiff and slender. T-10 jaws. Tail percentage, 29-38. No collar-
ette. Up to 16mm.

LITERATURE.

Apstein, C.

1911. Chaetognatha. Cons. Perm. Internat., Bull. Trimestr., part 2, pp. 170-
175, Plate xxiv.

Bigelow, H. B.

1914. Explorations in the Gulf of Maine, July and August, 1912, etc.. Bull. Mus.
Corap. Zool., a'oI. Iviii, No. 2.

1915. Exploration of the Coast Water between Nova Scotia and Chesapeake Bay,
July and August, 1913, etc. Bull. Mus. Comp. Zool., vol. lix. No. 4.

Conant, F. S.

1896. Notes on the Chaetognaths. Johns Hopkins Univ. Circ, vol. xv. No. 126.
Towler, G. H.

1906. The Chaetognatha of the Siboga Expedition. Siboga-Exped., Mon. xxi.

1907. Chaetognatha. Nat. Ant. Exped., Nat. Hist., voL iii.

1896. Plankton of the Faeroe Channel. No. 1. Proc. Zool. Soc, pp. 991-996,
Plate L.

Michael, E. L.

1911. Classification and Vertical Distribution of the Chaetognatha of the San
Diego Region, etc. Univ. Calif. Publ. Zool., vol. 8, No. 3.

1913. Vertical Distribution of the Chaetognatha of the San Diego Region, etc.
Amer. Natur., vol. xlvii, pp. 17-49.

Murray, J. and Hjort, J.

1912. The Depths of the Ocean. London, 1912.

Ritter-Zahony, R. Von.

1910. Chaetognatha from the Coasts of Ireland. Fish. Ireland, Sc. Invest.,

1910, iv.

1911. Chaetognathi. Das Tierreich.

Strodtmann, S.

1892. Die Systematik der Chaetognathen. Arch. Natur., vol. 58i, pp. 338-377.
1911. Die Chaetognathen. Nordisches Plankton, vol. v.

CANADIAy FISHEnir:S expedition', lOL'rlo

423

(a) Sagitta hexaptera d'Orbifrny.

1911. Eitter-Zahony, p. 12.
The specimens varied in size from ll-50mm. in length.

DISTRIBUTIOX.
r. G. S. "Acadia."

Station No.

16

17

44

56

74

75

Depth (metres).

over 2,000

over 2,000

over 1,000

over 1.000

over 1,000

over 1,000

Depth of Haul (metres).

Length fmm.).

200- 0 (V.).

0 (T.).

200- 0 (V.).

0 (T.).

270- 0 (V.).

0 (T.).

375-2.50 (C).

250- 0 (V.).

.32.5- 0 (V.).

55- 0 (V.).

c. 20- 10 (T.).

.325- 0 (V.).

55- 0 (V.).

c. 20- 10 (T.).

32 & .50

13, 21 & 36

17 & 20

11 & 12

30

Number.

Vertical. — With one exception this species was obtained only in deep open net
hauls, down to 200 metres or over, and did not occur in the shallower hauls (55
metres up). The exception was in a tow hau Itaken about 20 metres below the surface
at station 74. The two individuals obtained were the smallest taken (11 and 12mm.).

The small number of individuals found is quite inadequate for determining the
distribution, but the hauls made at stations where the species was found show its
absence below 250 metres, its rarity above 55 metres (and then only small individuals),
and its uniform presence in hauls made through intermediate depths. This agrees
with the finding of Michael (1913, p. 34) who suggests its maximum abundance as
existing between 50 and 100 fathoms, based upon twenty-eight specimens taken in
fourteen hauls. The presence of two small individuals near the surface in station 74
on the edge of the Gulf Stream, is explained by the fact that in warm waters this
species occurs quite to the surface in its younger stages.

Horizontal. — Sagitta hexaptera is a cosmopolitan oceanic form occurring in
tropical regions, but large individuals have been found far into the polar regions.

It was found only in the outermost warm water stations of the Acadia's cruises,
and it occurred in every one. As it is a form characteristic of intermediate depths,
from 100 to 200 metres, its distribution is an indication of the extent to whicli this
intermediate water has pressed in toward our shores from the open Atlantic. Tlie
imier limit of its distribution would appear to be well outside the continental shelf,
perhaps sixty or more miles in May and June, and rather closer, from twenty to forty
miles, in July and August. Its distribution (shown for July-August by the vertical

424 DEPARTMENT OF THE NAVAL SERVICE

interrupted lines in fig. 1) does not indicate that there has been any movement of this
intermediate water of the Gulf Stream in over the banks or up the gully leading to the
gulf of St. Lawrence.

^kJj /,-, i'/'"'

'6

Fig. 1— Distribution of fiulf Stream Chaetognaths, July- August li)15. S. enfl.ata P. draco

S. h'/puii<'lat'i

.S'. lyra

S. hcxaptcra I ,

K. suht/lis

Bigelow (1915, p. 298) obtained it in the July-August cruise (1913) of the
Grampus only in the outermost stations, apparently from 10 to 20 miles outside the
continental shelf, and in the more northern of the outer stations not at all, as these
were apparently not far enough out for it. "We may perhaps deduce from these facts
that this species comes nearer to the coast as the summer progresses, that its
distance off the coast increases as we go northward from Chesapeake bay to the
Grand Banks, and that along our shores it belongs to the Gulf Stream water coming up
from the south, and not to the cold boreal (water coming down from the north. The
occurrence of this species in the far north (74° N". according to Michael, 1913, p. 26)
and in the far south (77° S., Fowler, 1907, p. 3) would lead one to expect it in our

CANADIAN FISHERIES EXPEDITION, lOl-'flo

425

boreal oceanic water. As it belongs typically to lower latitudes, its absence may mean
that older individuals when carried toward the poles survive, but do not have any
progeny (owing to the absence of the warm salt surface water frequented by the young)
and as a result the cold water that passes toward low latitudes is devoid of this species,
the old individuals having all died off.

There is, however, some doubt as to how far it is carried toward the poles. Ritter-
Zahony considers that Fowler's Antarctic specimens belong to S. gazellae and not to this
species, and he gives the usual distribution as between the fortieth parallels north and
south.

(b) Sagitta enflata Grassi.

1911. Ritter-Zahony, p. 16.

The range in size of the specimens obtained is from 7-23mm. The larger indi-
viduals were all sexually mature. This species is easily recognized by the short tail and
the short sausage-shaped ovaries.

DISTRIBUTION.

C. G. S. "AcADu."

Station
No.

Hour.

41

42

44

.50

56

75

6 a.m.

9 a.m.
3 p.m.
9 p.m.

3 p.m.
9 p.m.

Depth
(metres).

360

over 1,000

over 1,000

151

over 1 , 000

over 1,000

Depth of Haul (metres). Length (mm.). | Number.

200- 0 (V.).

100- 0 (V.).

0 (T.).

200- 0 (V.).

0 (,T.).

270- 0 (V.).

0 (T.).

145-55 (C).

145- 0 (V.).

55- 0 (V.).

0 (T.).

375-250 (C).

250- 0 (V.).

.325- 0 (V.).

55- 0 (V.).

c. 20- 10 (T.).

11

7-23

7-20

IS

(fragment)

13
6-13

0
0
1
2
0
39
170
0
1
0
0

1

0

I

4
0

Vertical. — All the specimens obtained came from open-net vertical hauls or from
horizontal surface hauls. This species is a typical "surface form belonging to the upper
epiplankton. The majority of the specimens were taken in a surface haul at 3 p.m.

horizontal.

Horizontal. — Sagitta enflata is a troi)ical form ranging north to the fortieth parallel.
The present records appear to be more northern than any hitherto recorded for this species.
Two specimens were obtained at Acadia station 75, the position of which was 43° 30' N..

426

DEPARTMEWT OF TEE NAVAL SERVICE

56° 43' W. It belongs to the surface water of the Gulf Stream. It was not found on
the first cruise of the Acadia. On the second cruise of the Acadia it occurred in
abundance only at the southernmost station (station 44), where 209 specimens were
obtained. At each of five other stations, one to five specimens were taken (stations
41, 42, '50, 56 and 75). Its occurrence at station 50 is interesting as indicating the
movement as far as that point of the surface Gulf Stream water. Its distribution is
shown by the horizontal continuous lines in fig. 1.

Bigelow in his July- August cruise of 1913 obtained it south of cape Cod up to a
latitude of nearly 40°.

(c) Sagitta lyra Krohn.

1911, Ritter-Zahony, p. 13.

The specimens obtained varied in size from 15-38mm. in length. The individuals
obtained at Acadia stations 16 and 17 .on June 1 were not sexually mature, seminal
vesicles and ovaries not being easily seen, although the tests were distinct. Those
obtained on the later cruise were more mature, the ovaries being moderately long but
narrow, and the seminal vesicles appearing. This species and the next are easily
separated from the other species by the very evident connection between the anterior
and posterior fins.

DISTRIBUTION.
C. G. S. "Acadia."

Station No.

Depth (metres).

Depth of Haul (metres).

Length (mm.).

Number.

16

17

42
44
55

56
70

74

over 2,000

over 2,000

over 1,
over 1 ,
over 1,

over 1 ,
over 1 ,

000
000
000

000
000

over 1,000

over 1,000

200- 0 (V.).
0 (T.).

200- 0 (V.).

0 (T.).

200- 0 (V.).
0 (T.).

270-

0 (V.).
0 (T.).

270- 0 (V.).

90- 0 (V.).

0 (T.).

375-250 (C).
250- 0 (V.).

325- 0 fV.).

55- 0 (V.).

c. 20- 10 (T.).

.325- 0 (V.).

55- 0 (V.).

•. 20- 10 (T.).

325- 0 (V.).

55- 0 (V.).

e. 20- 10 (T.).

13-30

2.5-30
15, 16 & 19

(fragment)
15-25
24 & 27

26-32
25-32

38

18-33

29-33

4
3
0

5
0

2
0
0

7
4

1
0
0

4
0
0

10
0
0

CANADIAN FISHERIES EXPEDITIOS, IDUflo 427

Vertical. — This species was obtained only in deep open-net hauls down to 2'00 metres
or more, and in one closing-net haul below 250 metres. It was therefore distributed from
above 200 metres to below 250 metres. All the hauls from 90 metres up, and shallower,
were negative. Michael (1913, p. 31) found it very rarely above 25 fathoms, and
attaining its maximum abundance below 250 fathoms. He does not, however, distin-
guish S. maxima from this species. Ritter-Zahony (1911, p. 14) gives its distribu-
tion as from 100-200 metres downwards. It is thus typically in the deeper layers of
water.

Horizontal. — This species is cosmopolitan and extends well to the north in the Atlantic.
It is oceanic, being confined to deep water. In our waters its distribution is very similar
to that of S. hexaptera, it was found only in the outer stations. But it occurred in
more of these than did hexaptera, pressing farther in towards the continental shelf.
In the May- June cruise it was found at the same stations as hexaptera, and did not
occur at Acadia station 14, where a suitable haul was made. It would seem to have
been at that time about sixty miles oif the continental shelf, but the data are quite
insufficient. In the July-August cruise (its distribution is shown by the vertical
continuous lines in fig. 1) it was found in moderate abundance (about half-a-dozen
specimens) at the outermost stations (44, 56, 74, 75) with hexaptera, and as well in
some of the neighbouring stations (42, 55, 70), but only one or two si^ecimens in each
case. Thus it virtually came to the edge of the continental shelf. It might have been
expected at stations 45, 72 and 76. Station 45 was peculiar in giving only one Chaetog-
nath, S. serratodentata. Stations 72 and 76 appear to have had too great an amount
of coastal water (witness the presence of »S'. elegans). It is perhaps worthy of note that
at only one station (Acadia 16) were S. lyra and S. elegans found together, and at only
four stations were they both absent. The inner limit in distribution of S. lyra almost
corresponds with the outer limit of S. elegans. Although coming very close in, Sagitta
lyra does not appear to be carried over the banlvs or up the gullies between the banks
or up into the gulf of St. Lawrence.

It belongs to the deeper part of the bank of Gulf Stream water, and is carried in
small numbers into the " cold wall " of boreal water that Hjort (1912, p. 10) has shown
to exist along the southern side of the Grand Banks between the Gulf Stream and the
continental shelf, and that Bigelow (1915) has shown to become narrower as we pass
southward along the coast. "We may take arbitrarily a salinity of 35 per thousand as
forming the boundary line between the two. It is present in this boreal water only
south of the angle where the Gulf Stream is deflected to the south by proximity to the
Grand Banks, as if some mixing of the two waters occurred there.

The passage of this species from the Gulf Stream into the boreal oceanic water,
and the failure of 8. hexaptera to pass in a similar direction is perhaps to be explained
by the fact that S. lyra occurs in deeper, colder water than S. hexaptera, and is there-
fore more apt to pass through the bottom of the Giilf Stream. The rarity of S. hex-
aptera may also be responsible for our failure to get it in the boreal oceanic water.

Dr. Bigelow (1915, p. 297) lists S. lyra from each of his four stations taken just
outside the continental shelf south of cape Cod in July-August, 1913, and not from
those inside, except for two specimens from the gulf of Maine.

428

DEPARTMENT OF THE NATAL SERVIVE

(d) Sagitta maxima. (Conant.) Fig. 2,
1911. Eitter-Zahony, p. 15.

The rang'e in size is from 7 to 55mm. in length.

Yig. 2.-Sagitta
maxima x 2.

With one exception all the individuals were quite immature. Those obtained on
the first cruise had no evident gonads. The larger ones of the second cruise had the
ovaries of moderate size, but not mature, and the seminal vesicles distinct. Michael
(1911, 13. 37) has considered this form identical with S. lyra, but by following Ritter-
Zahony's account I have experienced no difficulty in separating the two species, except
with damaged specimens. The points relied upon have been : relation of anterior ends
of anterior fins to ventral ganglion and proportionate length of the tail. This species
reaches and matures at a much larger size than Sagitta lyra.

It is interesting to note that the specimens of this species described by Conant
(1896, p. 84) were obtained by the Albatross at station 2428, 42° 48' N. and 50° 55'
30" W., just inside the southern tip of the Grand Banks, and therefore in the " cold
wall " of boreal water. They were brought up in the trawl wings.

CANADIAX FISHERIES EXPEDITIOX, 191.',-io

429

DISTRIBUTION.
C. G. S. "Acadia."

Station No.

Depth (metres).

14

16

17

44

46

48

54

55

56

57

over 2.000
over 2,000
over 2,000

over 1,000

over 1,000

248

over 1,000

over 1,000

over 1,000
over 1,000

over 1,000
over 1,000

Depth of Haul (metres).

200- 0
0

200- 0
0

200- 0

0

270- 0

0
270- 0

0

270- 0

45- 0

0
270- 0
125- 0

0

270- 0

90- 0

0

375-250

250- 0

270- 90

90- 0

0
325- 0

55- 0

c. 20- 10

325- 0

55- 0
c. 20- 10

v.).

T.).

v.).

T.).

v.).

T.).

v.).

T.).

v.).

T.).

v.).
v.).

T.).

v.).
v.).

T.).

v.).

v.).

T.).
C).

v.).

C).

v.).

T.).

v.).

v.).

T.).

v.).
v.).

T.).

Length (mm.).

15-32

15-25

7-13
15-30

14-19

24

23

19-25
20&22

17-28

20-25
13-21
1.3-42

20-30

23-40

Number.

14

0
16

0

3 X 10

98

0

4

0

1

0

0

1

0

4

2

0

6

0

0

3

5

7

0

0

9

1

0

0

8

1

0

430

DEPARTMET^'T OF THE NAVAL SERVICE

' 'Acadia ' ' Concluded .

Station No.

Depth (metres).

Depth of Haul (metres).

Length (mm.).

Number.

74

75

76

79

85

S7

over 1 , 000

over 1,000

over 1,000

360

over 400

over 400

331

325-

55-

c. 20-

325-

55-

c. 20-

270-

c. 20-

325-

55-

270-

55-

c. 20-

270-

55-

c. 20-

290-

55-

c. 20-

0 (V.

0 (V.

10 (T.

0 (V.

0 (V.

10 (T.

0 (V.

10 (T.

0 (V.

0 (V.

0 (V.

0 (V.

10 (T.

0 (V.

0 (V.

10 (T.

0 (V.

0 (V.

10 (T,

10-16

15-24

13-36

12-40

10-16

15-17

15 & 23

Vertical. — Except in three instances, this species was obtained only in hauls
taken from a depth of 200 metres or more. The exceptions are small individuals,
25 m m.or less in length, and were obtained at Acadia stations 48, 54 and 72. The
conditions at these stations were peculiar. The surface oceanic species S. serratoden-
tata, the coastal species S. elegans, and two deep-water boreal species, the present one
and Eukrohnia hamata, all occurred together. These are undoubtedly places where
mixing of the different kinds of water occurs and where vertical currents might be
expected to bring temporarily nearer to the surface forms that are ordinarily to be
found only in deeper water. The number of individuals in each case was small (1,
2,1).

On the first cruise of the Acadia, numerous specimens were obtained in all the
hauls made from 200 metres to the surface (stations 14, 16 and 17) outside the con-
tinental edge and none in the hauls made from 100 metres to the surface (stations 12,
15, 26 and 27). On the second cruise (with the exceptions noted above) again only the
deeper hauls were productive. The shallower hauls were not very deep (90 metres or
less). At station 56, three individuals were obtained in the closing net from below 250
metres. These facts show an ordinary distribution of this species in our waters from
above 200 metres (but not above 100) to below 250 metres. Michael (1913, p. 32)
gives for *S'. lyr-a (in which he includes 8. maxima) a maximrun abundance below 250
fathoms and a decreasing frequency toward the surface (above 25 fathoms it was

CAXADIAX FISHERIES EXPEDITION, 1914-lo 431

extremely rare) for the San Diego region. Fowler (1896, p. 9f>2 as S. whartonx) in
his investigations of the Faeroe channel found it only on one occasion above 100
fathoms, and Ritter-Zahony for the coasts of Ireland found it regularly only below
100 fathoms.

In the Gulf Stream stations of the second cruise a gradation in depth according
to size is evident. At the southernmost station (station 44), the haul from 270 metres
up yielded no specimen longer than 19mm. At station 56, the next station north, the
haul from 250 metres up gave specimenes up to 21mm., and the haul from 375 to 250
metres, specimens up to 25 ( ?) mm. The northern Gulf Stream stations (stations 74
and 75) from a depth of 325 metres to the surface gave specimens up to 16 mm. and
24mm. respectively. The boreal stations yielded much larger specimens from similar
depths (e.g. up to 25, 28, 42, 55, 40, 36, and 40mm. at stations 54, 55, 57- 70, 72, 76,
and 79 respectively). Therefore, as we pass into warmer water the larger specimens go
decider and deeper down and only the smallest specimens occur near the upper limit of
distribution. It is worthy of note that at the Gulf Stream stations of the second cruise
(stations 44, 56, 74 and 75) in eaeli of the hauls, the average size of S. maxima (the
larger species) was less than the average size of S. lyra (the smaller species). This
seems to indicate that S. lyra attains its maturity and perhaps also its maximum abun-
dance in the upper part of the mesoplankton- and *S^. maa:ima its maturity and maximum
abundance in the lower part of the mesoplankton. These two closely related species,
though having to a great extent a coincident horizontal distribution would be rather
sharply separated in their vertical distribution, as Michael (1913) has shown to be the
case for other couplets of species in this group. Data as to the lower limit of distri-
bution S. lyra are lacking, although Ritter-Zahony (1910) appears to have obtained it
in quantity below 700 fathoms.

Horizontal. — This species is cosmopolitan, extending to the far north in the Atlantic,
so that it may be considered a cold-water species, distributed in all oceans in the depths.
In our waters in the depths that we have examined (down to from 200 to 300 metres)
it occurs in greatest abundance outside the continental shelf and inside the outermost
stations, that is, inside the Gulf Stream. Little can be stated as to its distribution
during the first cruise of the Acadia, owing to the fact that only three deep hauls
were made. At station 17 an extraordinary number were obtained, 12S in the one
open-net haul from 200 metres to the surface. Larger individuals were obtained at the
innermost of the thre stations, 30 and 32toim. at stations 17 and 14, respectively, as
opposed to 25mm. at station 16. The records indicate that it was present in maximum
abundance between station 16 and the Newfoundland banks, and decreased in abund-
ance toward the west and south. Its distribution in July-August is shown in fig. 3.
It occurred in moderate abundance at the outermost stations (7, 5, 8 and 4 specimens
at stations 75, 74, 56 and 44- respectively). At the remaining- stations outside the con-
tinental shelf, it occurred in maximum abundance at the northeast, and decreased in
abundance with almost perfect regularity, passing to the southwest, until it disappeared
altogether (14, 14, 8, 10, 7, 6, 4, 1, 0. 0 and 0 specimens at station 79, 76, 72, 70,
57, 55, 54, 46, 45, 42 and 41, respectively) considering in each case only the deep open-
net haul. It also occurred in fair abundance up the gully leading to the Gulf of St.
Lawrence. In the gully it was present in greater amount on the north side, the num-
bers obtained in the deep vertical hauls being 6, 5 and 2 specimens, respectively, at
stations 85, 86 and 87. Inside the Gulf of St. Lawrence, on the cruises of the Princess,
it was not found, perhaps because the hauls were not deep enough (not over 130
metres). The only other place where it was found was at station 48 in the deep water
inside the outer banks off Halifax, where a solitary specimen was obtained. Its dis-
tribution (fig. 3) suggests (1) that this species belongs typically to the deep boreal
water that is found against the side of the continent; (2) that this water disappears
as we pass southwest along the continent, doubtless seeking a lower level, unexplored
by our nets; (3) that some of it passes up over the banks south of Sable island to mix

432

DEPARTMENT OF THE NAVAL SERVICfJ

with the shallow- coastal water; and (4) that another portion passes up the gully-
leading to the St. Lawrence gulf but keeping mainly to the north side of the gully.

Its centre of abundance (fig. 3, closely placed lines) is then the deeper part of
the northern oceanic (boreal) water which flows to the south around the Newfound-
land banlvs. It is carried by the latter into the coastal water and beneath the Gulf
Stream. In the coastal water it must speedily perish, but in the Gulf Stream, the
smaller individuals at least find suitable conditions. The Gulf Stream on its way to
the north would seem to receive fresh additions of this species from the boreal water
beneath. The numbers obtained in the open vertical hauls from the south to the north

Fig. 3.

-Distribution of S. maxima, July-August 1915. Zones show frequencies of 1 to 5, 6 to 10 and 10

and over per station.

are 4, 5, 5, 7 at stations 44, 56, 74 and 75, respectively, showing an increase in the
number at the north. This may explain how the fauna of the Gulf Stream, as it
passes to the north, changes from tropical to boreal, the change in temperature killing
the tropical forms which are replaced by the boreal forms that enter the stream as
young individuals from the boreal water below. The growth of the boreal forms pro-
ceeds pari passu with the change in temperature, and they find themselves constantly
in water of suitable temperature for their continued existence.

CANADIAN FISHERIES EXPEDITION, lOUfla

433

Hjort (1912, p. 640) considers that this species (as S. gigantea) is arctic to boreal
in its distribution, and has found it as a typical inhabitant of the deep cold water of
the Norwegian sea. Apstein (1911, p. 173) records its distribution in European waters
as being restricted to the Atlantic and the Norwegian sea, but in one year at least
coming down the Norwegian gully to the western part of the Skager-Rack. It was
strictly limited to the deep water, remaining below 100 metres. This is very similar
to what we have found, the species tending to enter the St. Lawrence gulf along the
submerged Laurentian valley. It will probably be found at times well inside the
gulf in the deep water.

The distribution of this species may bo contrasted with that of S. lyra, its closest
ally. 8. lyra belongs to the Gulf Stream, but large individuals wander into the north-
ern oceanic water *S'. maxima belongs to the northern oceanic water, but small indi-
viduals wander into the Gulf Stream. Both species are apparently unfitted for life
in water of low salinity like the coastal water, regardless of temperature.

(e) Sag^tta serratodentata Krohn. Fig. 4.
1911. Ritter-Zahony, p. 22.

Fig. 4. — Sagitta
serratodentata.

The range in size is from 6 to 24m'm. in length. All the larger individuals were
sexually mature. The slender build of this species- and the early appearance of the
seminal vesicles on either side of the tail, make it easily distinguishable from our other
Chaetognaths. A character to which attention does not appear to have been called is
the presence in the young of a distinct bridge between the anterior and, posterior fins
on each side. This tends to disappear with age. In young individuals the seiTations
on the hooks are seen with difiiculty, if at all. The variations in the descriptions of
this species, as taken in different localities, make one question whether several species
have not been confounded. The great differences in the conditions throughout our
waters give us almost the extremes of these variati(ms. In the warm water at Acadia
station 44, the largest individuals were only 12mm. long. Both their male and female
gonads were mature. The jaws were few (5-8), the tail proportion small (23-27 per

434

DEPARTMENT OF THE NAVAL SERVICE

cent) and the body relatively stout. At Acadia station 38, individuals as long as
22mm. were obtained, and those as long as 15mm. were immature. The jaws were
more numerous in these (7-10), the tail proportion larger (25-32 per cent), and the
body more slender. If these are one species, the differences in structure will be due
to the differences in the conditions under which they have developed. These hifFer-
ences are similar to those seen in the varieties of S. elegans (see -under that species)
occurring in localities where different climatic conditions prevail. In both the cold
water develops a type of larger size, with more jaws, and a higher tail percentage.
The number of jaws increases with age (there may be latterly a decrease) and the
maximum number in the cold-water type is higher than is found in the warm-water
type (though the difference is not great). The following are the numbers of jaws
found in the two types : —

Tropical water. ("Acadia" Station 75).

Length (mm.)-

7

8

9

10

11

12

13

Number of jaws

6

6

6

6

5

7

6

7

6

6

6

6

7

7

6

6

6

6

7

7

6

6

6

6

7

7

6

6

fi

7

8

7

7

7

6

7

8

7

7

7

7

7

8

8

7

7

7

8

8

7

7
7

7

7
7
8

8

8

8

8

8

8

8

Boreal Water. ('"Acadia" Stations 17, 38, and 85).

Length (mm.).

10

11

12

13

14

15

16

17

18

19

20

7
7
7
8

7
7
7
8

7
8

7
8
8
8
8
9
9

7
8
8
8
8
8

8
8
8
9

8
8
8
8
8
8
9

8
8
8
9
9
9

7
8
8
8

8

9
9

CAXADIAX FISillERIES ^XI'KDlTlOy, lOUl.'t

435

The comparative variability in the mimlx>r of jaws in individuals of the same size
makes it necessary to examine larger numbers of individuals than would otherwise be
the case. Although the number is not very large, it is fairly evident from the figures
given that there is a very gradual but steady increase in the number of jaws, and this
is irrespective of the type, individuals of the same length in the two types having
equal numbeis of jaws (or slightly more in the larger type).

In the ease of the tail percentage there is a decrease with age. The following are
the result? of measurements of the percentages in the two types of S. serratodentata.

Boreal Water. ("Acadu" Station 38.)

Length (nini.).

10

11

12

13

14

15

16

17

Tail pcroentages

29
30
30
32
32

28
29
30
30
30

27

28
28
28
29

26
27

28
28
30

26
27
28
28
28

25
25
26
27
28

26
26
27

27

25
27

For the larger sizes it was necessary to examine specimens from another point.
Boreal Water. ("Acadl\" Station 85.)

Length (mm.).

17

18

19

20

24

23
23
24
24

23

23

Tropical Water. ("Acadia" Station 75.)

Length (mm.).

Tail percentages.

8

9

10

11

26

26

24

24

26

26

24

24

27

26

25

24

28

27

25

25

28

25

26

12

23
23
23
24
24

For the sm.allest sizes specimens from another station were taken.

6551—32

436

DEPARTMENT OF TEE NAVAL SERVICE

Tropical Water. ("Acadia" Station 41.)

Length (mm.).

Tail percentages.

30

28
30
30
32

29

The range in percentage is the same for the two types (32-23), but for any given
length it is very different, for example, for 12mm., 23-24 per cent and 27-29 per cent.
If we consider 20mm. the ordinary upper limit for the boreal water and 12mm. that
for the tropical water, we find that for corresponding sizes the percentages are as
nearly the same as could be expected. Half-grown individuals show percentages of
30 and 27-29, respectively; two-thirds grown individuals of 26-28 and 25-28; fully-
grown individuals of 23-24 and 23. , , • n i-

It is probable that we have not to do with two races, but that the tropical lorm
is constantly brought to the boreal water, keeping the strain uniform. The differences
may be confidently be referred purely to the environmental factors. Cold may be said
in this species to increase the length, delay maturity till a much greater length is
attained delay the decrease in tail percentage correlative to maturity, and increase
the number of jaws. We have the number of jaws correlated with size and the tail
percentage corrleated with maturity (attainment of maximum size and also maturity
of sexual organs).

DISTRIBUTION.
"Acadia."

■ tation No.

12

Hour.

3 a.m

6 a.m
6 a.m

9 a.m
3 p.m

Depth
(metres).

45

over 2,000

over 2,000
over 2,000

Depth of Haul (metres).

60- 0 (V.).
0 (T.).

40- 0 (V.).

0 (T.).

100- 0 (V.).

0 (T.).

70- 0 (V.).

200- 0 (V.).

Length (mm.).

19
10-15
15-20
14
13
13-15
16-17

0 (T.).

14
14-15
16-24

^Number.

1
35
43

3

2
3-MXlO
3
0
1
3
18+1X10
0

CAXADIAX FISHERIES EXPEDITION, 191.^-15

"Acadia" — Continued.

437

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.).

Number.

15

16

17

18
19
25

26

27
28

38

39

40

9 p.m.
3 a.m.

9 a.m.

6 p.m.
9 p.m.
6 p.m.

12 m. n

3 a.m.
3 a.m.

9 p.m.
12 m. n
3 a.m.

over 2,(X)0

over 2,(X)0

over 2,000

over 2,000

over 2,000

122

over 400

over 400
over 400

170

95

134

100- 0
0

(V.).
(T.).

200- 0 (V.).

0

200- 0

0
0
0

120- 0
10(?)- 0

100- 0
0
0

100- 25
0

150- 0

(T.).

(V.).

(T.).
(T.).
(T.).
(V.).
(T.).
(V.).
(T.).
(T.).
(C).
(T.).
(V.).

100- 0 (V.).

0

100- 0

(T.).

(V.).

25- ? (V.).

0

125- 0

125- 0

100- 0

0

(T.)...

(V.)I..
(V.)II.
(V.)...
(T.)...

16-18
13-15
16-20
6-7
13-15
15-20
9-21
4-12
15-21
11-20
17-18
15-19
13

15-17

c. 17

16

10-15

15-16

7-15

15-22

9-14

12-15

15

12-15

15-17

10-17-5

12

10

shrivelled
specimens

9
5X2

19X2

58X10

3X10

27X10

+ +

43+19X10

16+13X10

c. 30

2

c. 20

1

0

3

0

X

0

1 seen

10+20X10

4

30+25x10

19+3X10

X X

12X10

4

5X5

14

X X

2

1

0

X

6551—32*

438

DEPARTMENT OF THE NAVAL SERVICE

"Acadia" — Continued.

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.).

Number.

41

44

45

46

47

48

50

6 a.m.

9 a.m.

3 p.m.

9 p.m.

12 m.n.

6 a.m.

12 m.n

9 p.m.

12 m.n

.360

over 1,000

over 1,000

over 1,000

over 1 , 000

200- 0 (V.).
100- 0 (V.).

0 (T.).
200- 0 (V.).

0 (T.).
270- 0 (V.).

0 (T.).

270- 0 (V.).

90- 0 (V.).

0 (T.).
270- 0 (V.).

40

125- 0 (V.).

250

151

131

90 -0 (V.).

0 (T.).

270- 0 (V.).

45- 0 (V.).

0 (T.).

145- 0 (V.).

14.5- 55 (C).
5.5- 0 (V.).

0 (T.).
125- 55 (C).
12.5- 0 (V.).

0 (T.).

6-9

10-12

10

7-11

7-11
7-12
6-11
7-15

5-13
5-16
5-14
16-20
9-14
15 & 17

5-1^

12-5
12-14
16-20

16
10-14

17
10-16
9& 15
14-15
15-19
11-16

25

3

1
67

0

26

58

8X4

21

0
14+4X5

2

+

X

13+2x10

2
X
+

0

1

0

2X5

12

5

1

5+1X5

1

+ +

2X5

3+1X5
4

+

CANADIAN FISHERIES EXPEDITION, JOL'rlo
' 'Acadia" — Conlintwd.

439

Station Xo.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.).

Number.

52

53

54

56

58

60

70

72

3 a.m.
6 a.m.

9 a.m.
12 m...

3 p.m.
9 p.m.

12 m.n.

6 a.m.
12m...
p.m.

99

95

over 1,000

over 1,000

over 1 , 000

over 1 , 000

187

99

over 1,000

over 1,000

90- 0 (V.) II.

0 (T.)...

90- 0 (V.).

0 (T.).
270- 0 (V.).
125- 0 (V.).

0 (T.).
270- 0 (V.).

90- 0 (V.).

0 (T.).

375-2.50 (C).

250- 0 (V.).

270- 90 (C).

90- 0 (V.).

0 (T.).

180- 55 (C).

55- 0 (V.).

0 (T.).

90- 0 (V.).

0 (T.).

325- 0 (V.).

55- 0 (V.).

c. 20- 10 (T.).

325- 0 (V.).

55- 0 (V.).

c. 20- 10 (T.).

17

13 & 14

16-18

9

11-12

15-19

19

1.3-14

7-12

8

17

16

9-15

e. 8

7-9

8

9& 12

9-12

10 & 12

9-10

8-13

18-20

7-5-9

15

small

13-14

9-13
16

1
2
2

1X5
3
3
X
3
0

c. 12
2
1
2
7
2
42
1
2
15
2
4

c. 15
2

3X5

1X5
X
0
0
4
0
0
7
1

440

DEPARTMENT OF THE NAYAL SERVICE

' 'Acadia ' ' — Concluded.

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.).

Number.

74

75

77

85

86

6 p.m.

9 p.m.

9 a.m.

9 a.m.

12 m.

3 p.m.

over 1 , 000

over 1 , 000

over 1 , 000

over 400

over 400

331

325-

55-

c. 20-

325-

55-

c. 20-

c. 20-

270-

55-

c. 20-

270-

55-

c. 20-

290-

55-

c. 20-

0 (V.).

0 (V.).
10 (T.).

0 (V.).

0 (V.).
10 (T.).
10 (T.).

0 (V.).

0 (V.).

10 (T.).

0 (V.).

0 (V.).

10 (T.).

0 (V.).

0 (V.).

10 (T.).

8-11

7-13

7-12

6-12

6-12

8-14

10-14

18 & 19

15-21

11 & 21

17

1.5-20

19

19

19

13 & 14
17-20

52

21

+

25X4

50X5

+ +

c. 12

2

XX
4
1
1 seen

0

2 seen
5 seen

"Prince."

12 m.

200 180- 0 (V.).

e. 20- 10 (T.).
2- 0 (T.).

19-5
5-5

1 seen

0

In discussing the distribution of this species, it has been thought advisable to
distinguish between small and large individuals.

Ritter-Zahony states that in warm water this species rarely reaches more than
15mm. in length. As we have both warm and cold water in the area explored, those
under 15mm. may show a different distribution from those over 15mm. In the table
given above in most cases these two groups have been separated. It must be re-
membered, however, that this division is quite arbitrary, warm water individuals
being occasionally longer than 15mm. and cold-water individuals being of all sizes.

Vertical. — Fowler and Ritter-Zahony regard this species as typically epiplaiik-
tonic, but extending int othe mesoplankton. Michael, on the contrary, for the San
Diego region, states that the species reaches its maximum abundance below 150
fathoms, and that only the immature were taken above 100 fathoms except at night
when the larger specimens came up as far as 50 fathoms (1911, p. 150). This contra-
diction would indicate that diiferent species have been confounded.

CANADIAN FISHERIES EXPEDITION, lOlJflo

441

The small individuals of the (iulf Stream stations were taken in abundance at
or near the surface at 3 p.m. (station 44), G p.m. (station 74), and 9 p.m. (station
75), and these hauls contained mature individuals, thoug-h small. At station 50, two
si>ecimens were obtained in the deep closing-net haul below 260 metres, and forty-
two from 250 metres to the surface. The records at station 74 and 75 show that
nearly as many (21 as opposed to 35) or more (50 x 5 as opposed to 25 x 4) were
obtained from the shallow vertical haul (55 — Om.) as from the deep vertical haul
(325 — Om.). These facts indicate that the warm-water variety of the Gulf Stream
occurs chiefly near the surface, even during the day.

The large individuals of the colder water are to bo found in the intermediate
water (between Gulf Stream and coastal water) where mixing may be supjwsed to be
going on. The vertical currents that are doubtless i:)rescnt here would tend to bring
them nearer to the surface, and so influence the vertical distribution.

The mixing would also tend to give the opposite result, namely, fewer aft the
surface, when the surface water comes from the cold shallow coastal water, in which
S. serratodentata does not occur. However, the records show fairly conclusively that
these large individuals do come to the surface at least dTiring the night, num1x?rs
having been taken near the surface at 9 p.m. (Acadia Stations 19, 38, 50), at 12 mid-
night (Acadia stations 39, 46, 51) at 3 a.m. (Acadia stations 5 and 16), at 6 a.m.
(Acadia station 47), and at 9 a.m. (Acadia stations 17 and 85). At no stations taken
about the middle of the day were large individuals obtained in numbers, yet si^ecimens
were taken near the surface at 12 m. (Acadia station 86) and at 3 p.m. (Acadia stations
72 and 87). At Acadia station 50, twenty-seven specimens were caught in the vertical
open net from 145 metres to the surface, one in the closing net from 145 to 55
metres, eleven in the open vertical net from 55 metres to the surface, and very many
at the surface. This would indicate that at 9 p.m. the bulk of the individuals were
above 55 metres. On the other hand, at station 51 almost as many were obtained
from 125 to 55 metres as from 125 metres to the surface, so that the data are
inconclusive.

In the Laurentian channel at Acadia stations 85, 86, and 87, the vertical hauls
indicate that it came very near the surface, but was as abundant in the depths as at
the surface, or perhaps more abundant. The three stations gave fourteen in the deep
hauls, as compared with three in the shallow hauls. This suggests that it is farced
into deeper water by the presence near the surface of water of too low a salinity. If
it comes to the surface is spite of the unsuitability of the surface water, it will
doubtless perish and thus fail to penetrate as far into the St. La\\Tence gulf at does
E. liamaia.

Individuals a)jove ISmni. in length were obtained at or near the surface at
practically evei-y hour of the day. Taking the stations at which these large individuals
were obtained, we have the following positive and negative results for the near
surface hauls : —

6 a.m.

9 a.m.

12 m.

3 p.m.

6 p.m.

9 p.m.

12 m.n.

3 a.m.

1
2

3
0

1
2

2

1

1
0

3
1

4

1

5
0

Negative

There can be no doubt that this species is truly epiplanktonic in both cold and
warm water, though whether or not it is driven below the surface to any extent. 1)>
the light during the day is an open question.

Horizontal. — S. serratodentata is cosmopolitan, occurring in all oceans except in
the far north and the far south. Its most northerly record is 60° 2' N. and 22° 56' W,

442

DEPARTMENT OF THE XAYAL SERVICE

It extends farther to the north than anj" of the other epiplanktonic warm water
forms. In our area, too, it extends farther inshore than any of the others, being able
to withstand the lower temperature and salinity better. It seems to be equally at home
in the Gulf Stream and in the cold boreal water next the banks. It grows to a much
larger" size in the latter, but this difference can scarcely be used for dividing the
species into two groups. The presence of individuals above 15mm. in length is
indicative of the presence of boreal water, but the presence of small individuals is
not necessarily indicative of the presence of Gulf Stream water. Small sexually
mature individuals might be indicative of Gulf Stream water, but I have not correlated

Fig. 5. ^Distribution of S. serratodentatu. May- June 1915. The zones indicate frequencies of 1 to 2r),

26 to 100 and 100 and over per station.

distinct from the cold bank water. Fig. 5 shows its distribution during the first
cruise of the Acadia. It is virtually confined to the deep water off the continental
shell, passing upwards over the banks only at stations 5 and 6 on the lower part of Sable
sexual maturity with size in my records. Taken as a whole the species is indicative
of the extent to which oceanic water (either Gulf Stream or boreal) extends, as

CAXADIAX FISHERIES EXPEDITIOX, lOl.'rlo

443

island bank. The deep water between Sable Island bank and Halifax seems to have
been free from it. It can only be considered to have been abundant at the two outer
stations (IG and 17), although the lack of uniformity in the hauls renders the point
uncertain.

Fig. 6 shows its distribution during the second cruise of the Acadia. Owing to
the route of the second cruise being different from that of the first, a strict comparison
is difficult.

Fig. (i.— Distribution of ^. scrratodcnlata, .Jnly-.\ugust l!tl5. Vertical lines indicate the boreal form with
zones showing ffequencies of 1 to 2o, 2d to 100 and lol to 300. Horizontal lines indicate the Gulf
Stream form with zones showing frequencies of 1 to 50 and 51 to 300.

Several points are noteworthy: first, its presence in quantity in the deep water
between Sable Island bank and Halifax; second, its absence on Sable island bank at
station 59, where it was present on the first cruise (station 6); and third, its absence
at station 76 well out in deep water off the centre of the mouth of the Laurentian
channel. The sinuosities in the inner limit of its distribution are much the same in
the two cruises, except that they have been shifted toward the west in the second
cruise. The species does not seem to have pressed farther in to any appreciable extent

444 DEPARTMENT OF THE NAVAL SERVICE

during the intervening two months. With S. maxima it extends well up the Laurent-
ian channel as shown at stations 85, 86, and 87 and, like that species- it is most abund-
ant on the north side of the channel. The decrease in abundance from north to south
across the channel is very evident, for the deep vertical hauls eight, four, and two
specimens were obtained at stations 85, 86, and 87, respectively, and for the shallow
vertical hauls two, one, and zero specimens for the same stations.

It was not obtained at any of the stations of the Princess cruises and, being a
surface form, it could scarcely have been missed. It does not therefore extend into
the St. Lawrence gulf, doubtless being killed by the cold brackish surface water. Its
absence over the banks south of Newfoundland (St. Pierre and Green banks), and
over those north of Sable island (Banquereau, Misaine, etc.) and along the Nova
Scotia shore is noteworthy as denoting the absence here of oceanic water.

Bigelow has shown that it extends well up into the gulf of Maine, keeping to the
deep water near the centre, in July and August of both 1912 and 1913 (1914, p. 121,
and 1915, p. 299). Our record of September, 1915, at Princess station 3, in the deep
water between Grand Manan and Nova Scotia, shows that it extends at least up into
the mouth of the Bay of Fundy. It was absent at Prince station 2 off Campobello
island, farther up the bay. The small number of specimens obtained at Prince station
3, and the lateness in the season, indicates that this is its northern limit in the bay.

It may perhaps be possible to delimit pure Gulf Stream conditions as exhibited
by this species, when we take note of both size and abundance. This is shown in
fig. 6, horizontal lines representing the small variety and vertical lin'es the large.

The outermost stations gave in the vertical hauls comparatively large numbers of
individuals, whose upper limit in length was 13mm. Taking these together with the
stations that show similar results and we have the following list of " Gulf Stream"
stations: Station 41, 200-Om., 6-9mm., twenty-five specimens; station 42, 250-Om.,
7-llmm., sixty-seven specimens; station 44, 270-Om., 7-llmm., twenty-six specimens;
station 45, 270-Om., 6-llmm., thirty-two specimens ; station 56, 250-Om., 7-9mm., forty-
two specimens; station 74, 325-0'm., 8-llmm., thirty-five specimens; station 75- 325-
Om., 6-1 2mm., 25 x 4 specimens. The line separating these stations from the others
nearly coincides with the outer limit of specimens over 15mm. in length.

There are several stations at which a few small individuals were obtained (station
40, 54, 57, and 70), but the degree of sexual maturity shown by them indicates that
they belong to the larger cold water form. A line drawn just inside stations 41, 45,
56, 74, and 75 would separate the warm water form from the cold water form. It must
be emphasized, however, that this line cannot be sharp, as there is a transition from
one form to the other. A study of the specimens from stations 44, 45, and 46 shows
this. At station 44 a maximum size of 12mm. is attained ; at station 45, of. 15mm. ;
and at station 46 of 20mm. There is the same gradation in the change from a stout
to a slender body and from early to late maturity.

Its absence at Acadia stations 59 and 76, where numbers of S. elegans were
obtained indicates that at these points definite tongues of coastal water extend out
into the boreal or mixed water, which doubtless come from the mass of coastal water
present over and between the banks north of Sable island. These two tongues are
shown in fig. 6. On the earlier cruise of the Acadia these two tongues are fused as
shown in fig. 5, this species not ocurring at Acadia stations 6 to 10. The distribution
of *S'. elegans during the same cruise (fig. 8) shows the two tongues but they are close
together.

On neither cruise is there any indication that the cold coastal water of the New-
foundland banks (where 8. serratodentata was not found) has to any extent flowed
out from the banks into the water outside the continental shelf, but it does appear that
the water north of Sable island has done so.

Though the quantitative data as to the distribution of this species are incomplete,
the centre of ai)undance during the first cruise of the Acadia, as shown in fig. 5, was

CANADIAN FISHERIES EXPEDITION, 19U-15

445

definitely at the outermost stations (10 and IT). It decreased in abundance to the
north and to the west (perhaps also to the south). This perhai)s indicates that sur-
face boreal water was at tliat time cmninj;- around the southern side of the Newfound-
land hanks.

This area was not explored during the second cruise. The distribution at that
time, as shown in fig. G, would indicate the presence of very little surface boreal water
south of the Newfoundland banks, probably owning to the pressing in of the surface
Gulf Stream water. The centre of abundance at this time was off the lower end of
Nova Scotia, where no stations were taken on the first cruise. Whether the animals
were transported to this point from the north during the intervening two months or
not must remain problematical, although the direction of the known surface currents
in these waters would support such a view.

The rarity of S. serratodentata in north Kuropean waters as recorded by Ritter-
Zahony (1910, p. 2) and Apstein (1911, p. 174) is remarkable. It is rare even in the
open Atlantic off Ireland. Its occurrence on one occasion in the deep water of the
Skager-Rock, and only at a depth of 150 metres or more (Apstein) indicates a res-
trictdon to the deep salt water on the rare occasions when it is carried into the North
sea.

(/) Sagitta bipunctata, Quoy et Gaimnrd.
1911. Ritter-Zahony, p. 10.

" Acadia."

Station No.

Hour.

Depth (metres)

Depth of Haul (metres).

Length (mm.).

Xuniber.

44

3 p.m.

Over 1,000

270-0 (V.).
(0. T.)

12 & 15
12-15

2

5

This species was obtained only at the southernmost station of the second cruise
of the Acadia, at station 44 (fig. 1, horizontal dotted lines). It occurred in both sur-
face and open-net vertical hauls. It is a tropical surface form, but extends well north
in the Atlantic. Owing to its confusion with other species the records of its occur-
rence are untrustworthy.

It was obtained l)y Bigelow in July- August, 1913, only in his more southern and
outer stations south of cape Cod.

(.'/) Sagitta elegans Yorrill. Fig. 7.

1911. Ritter-Zahony, p. 17 and figs. 1-3.

This is the characteristic Sagitta of our Atlantic waters, from its general occur-
rence in the shallow water all along the coast.

The range in size is from 2 to 52mm. iu length. Ritter-Zahony divides the species
into three subspecies, of which two, elegans and arctica, would be represented here. As
these are not distinct but are connected by intermediates, I have not thought it worth
while to consider them separately. The differences between the two are similar to the
differences between the two types of S. serratodentata- and are no doubt due to the same
cause, namely, difference in temperature during development. It is interesting to note
that the only place where individuals longer than 3Gmm. were found, was in the Bay
of Islands. In that place there is an extensive layer of water below the freezing point,
from about 50 fathoms to as much as 150 fathoms deep. Such an extreme condition
was not found elsewhere, and approaches the conditions in the Arctic regions.

446

DEPARTMElsT OF THE xYAYAL SERVICE

Eitter-Zahony gives the upper limit of S. elegans as 30mm. and of 8. elegans
arctica as 44mm. Our measurements would indicate that 8. elegans reaches a length
of 36mm. (an individual from the Bay of Fundy, (which is almost in the region from
which the species was first described, measured 35mm.), and 8. elegans arctica a length
of 52mm.

The majority of the larger specimens are sexually mature, but even some of the
largest are immature. The size at which maturity is attained apparently varies with
the region. JSTo measurements of the sexual organs were made, but on examining
material from a number of points and observing the state of the ovaries and seminal

Fig. 7.

Sagitta
.k4.

vesicles it was seen that in the Bay of Islands No. S3 station 57), the sexual organs
were maturing only when a length of 30mm. was reached (but even as low as 22mm. in
a catch by the young fish trawl); northern part of gulf {Princess station 16), 23mm.;
middle part of gulf (Princess station 33), 23mm.; southern part of gulf (Princess
station 25). 20 mm.; southern coast of Newfoundland (Acadia stations 20, 35, 83),
24mm.; off northern end of Nova Scotia (Acadia stations 67 and 90), 25 mm.; off
southern part of Nova Scotia (Acadia station 38), 24mm.; in the Bay of| Fundy,
(Prince station 1), 22mm. At Prince station 3 at the mouth of the Bay of Fundy, the
specimens even as large as 35mm. had immature ovaries. Other factors are doubtless
involved.

CAXADIAN FISHERIES EXPEDITIOX, lOJ.'rl'j

447

The subject demands much more extensive investigation than the present oppor-
tunity affords, but from the cursory examination made, it would appear that in warmer
water the species matures at a smaller size, as is seen very definitely to be the case with
S. serratodentata.

The southern gulf specimens in early maturity approach the Baltic subspecies,
S. elegans haliica. It is rather difficult to say what is the upper limit in size in this
area, owing to the currents bringing outside individuals into the area. As the chief
current sweeps across this part of the gulf from west to east, the individuals of the
eastern side are perhaps most representative. In June, at Princess station 20 the
largest individual was 25mm. long, at station 25, farther north, 32mm. long. In August
at Princess station 50, the largest was 20mm. long; at station 49, 20mm. long, and at
station 48, 26mm. long. In June, at No. S3 stations 4-15 (all in this same area between
Prince Ed'ward, Cape Breton, and Magdalen Islands) the largest individuals were
26mm. long. This (26) may be considered as the maximum size for individuals that
have grown up in the area (the larger ones at Princess station 25 may well have been
carried in from without. In the Bay of Fundy at Pnnce station 3 the maximum size
was 35mm. In the Bay of Islands at A'o. 33 stations 57 and 59 the maximum was
45mm. (at station 57 a very large number were obtained with the young fish trawl, and
among these one individual 52mm. long was seen).

The maximum size therefore varies |with the temperature, being higher in colder
water.

S. elegans haltica, according to Ritter-Zahony, has from eight to ten jaws on each
side, the number being largest in specimens of medium size (about 16mm.). In S.
elegans elegans, the number is from eight to eleven, with probably no decrease in older
individuals. In S. elegans arctica, the number is from eight to twelve, with apparently
no decrease in older individuals.

Counts were made to determine whether a difference could be detected in this
respect between the Bay of Islands specimens and those from the Lower Gulf.

Bay of Islands (No. 33 Statiox 57.)

Length (mm.)-

Xo. of Jaws.

Length (mm.)

Xo. of Jaws.

20

11-12
10-11
12-12
10-10
11-11
12-12
12-12
12-12
12-12
11-11
13-13

39 . ...

11-11
12-12

1 ■■> 1 9

21

40

09

40

24

40

40

]0 |0

24

13 13

2.5

42

12-12

10 10

25

43

26

44

10 10

28

46

13 13

29

49 . .

9-10
10-11

35

52

448

DEPARTMENT OF TEE T^'ATAL fiERTICE

Bay of Islands (No. 33 Station 54.)

Length mm.).

No. of Jaws.

Length (mm.)

No. of Jaws.

13

9-9
10-10
10-11

15

15

8 9

14

10-11

14

Lower Gulf. (Princess Station 25.)

Length (mm.).

No. of Jaws.

Length (mm.)

No. of Jaws.

22

11-11
11-11
12-12
11-11

26

12-12

24

27

11-11

24

27

30

11-11

25...

12-12

Lower Gulf. (Princess St.\tion 50.)

Length (mm.).

No. of Jaws.

Length (mm.)

No. cf Jaws.

q

9-9

9-10

10-10

14

10-10

11

15..

10 11

14...

So far as can be seen, the number of jaws is dependent upon the size, irrespective
of the degree of maturity. Only in the very largest individuals is there any indication
of the decrease in number that is so characteristic of certain other species. •

The number of jaws is therefore proportional to the size, and becomes greater in
the colder water.

The subspecies S. elegans haltica Ritter-.Zahony (1911, p. 18) differs from both
the typical and arctic subspecies in having a relatively shorter tail, that is, its tail
percentage (the percentage of the length of the tail in the total length) is less. It
seemed likely that this character would show differences characteristic for each region
and that the Lower Gulf specimens would approach the Baltic type. To test this, in
the first place a series of small individuals from 11 to 16.5 mm. long, taken in July
and August at different poins, were studied. There were none available from the Bay
of Fundy. The results were as follows : — •

Bay of Islands (No. 33 Station 54).

Length (mm.).

12

12-5

13

13-5

14

15

15-5

16

Tail percentages

19
19
21

19
20

IS
19
20

19
19
20

19
21

19

18

19

CANADIAN FISHERIES EXPEDITION, 191f,-15

South Coast or Newfoun-dland (" Acadia " Station 83.)

449

Length (mm.).

12-5

13

13-5

14

15

15-5

16-5

Tail percentages

19
20
21

18
18
18

18

20

19

17

18

Outer Coast of Nova Scotia (" Acadia " St.\tion 37).

Length mm.).

11

11-5

12-5

13

15

16

16-5

T-iil

20

20

18

19

19
19

19

18

18

19

Southern Part of Gulf. (" Princess " Station 48).

Length mm.).

11

12-5

14-5

15

15-5

16

16-5

Tail percentages '. . . '

18

18
20

17
18
19

17
18

18
19

18
18

17

17

18

The differences shown in the above tables are very slight. The Bay of Islands
specimens have, on the whole, the highest tail percentage, and the southern gulf speci-
mens the lowest. Larger individuals show more marked differences. A series from
21 to 27mm. were taken from three localities: (1) Bay of Islands (No. S3 station 57)
with icy cold bottom water doubtless throughout the year; (2) Bay of Fundy (Prince
station 3) with moderately cool water throughout the year; and (3) the southern part
of the gulf (Prindess station 25) with water very warm in summer and very cold in
winter.

The tail percentages for the different sizes are given in the following tables:—

Bay of Islands (No. 33 Station 57).

Length (mm.).

21

22

23

24

25

26

27

Tail percentages

20
20

20

22
22
20

19
21
20
21

20
20
20
20
19
21
20

20
19
19

19

20
20

20

450

DEPARTMENT OF TEE 2\"Ay.4L SERVICE

Bay of Fundy. (Prince Station 3).

Length (mm.).

21

22

23

24

25

26

27

17
18
17
IS
17

16
18
16
17
16
18

17
17

17

17
18

17
19
18
19
16
19
17

18
19
17
17
18
18
17
20
18
17
17
18
19

17

19
17
17

17

....

17

19

19

Southern Part of Gulf. (Princess Station 25).

Leni2:th finni.).

21

22

23

24

25

26

27

16
16
17
16

15
15
15
16
17
15
16

17
16
17
19
18

15
16
14
15
18
16

16
16

16
18
17
16
19
18
15
18

16

16

The general result is that for the Bay of Islands the percentage varies from 19 to
22, with the greatest number at 20; for the Bay of Fundy, from 16 to 20, with the
greatest number at 17 ; and for the lower part of the gulf from 14 to 19, with the
greatest number at 16. The individual sizes show similar gradations.

We have very little knowledge as to the conditions under which these forms
grow, and as to their life-histories, but the greater differences in tail percentages
shown by the larger individuals is, I think significant.

As will be shown farther on, the young individuals occur much nearer the
surface than do the older ones. This surface water becomes quite warm in the
summer throughout the region (except in the Bay of Fundy, from which we have no
specimens) so that conditions are much the same for the young in all the regions and
as a result, the tail percentages do not greatly differ. The older individuals seek the

CANADIAN FISHERIES EXPEDITION, 1914-15

451

deeper water and have lived long enough to experience the totality of conditions
characteristic of the several regions, and consequently exhibit greater diflFerences.

The next point is: do the cold-water individuals ever attain as low a tail per-
centage as those of warm water? Large individuals from the Bay of Islands show
the following: —

Bay of Islands. (No. 33 station 57).

Length (mm.).

30
31
39
40
42

Tail percentage.

20

18

18, 20

18, 18, 19, 19, 19

19

Length (mm.

44
46
49
52

Tail percentage

17, 17
17
17
19

Above 40mm. in length the Bay of Islands specimens reach a tail percentage
(17) equal to that of specimens between 20 and .30mm. in length from the Bay of
Fundy. They would appear never to reach as low a tail percentage as do those of the
lower gulf.

The tail percentage is seen to be a function of the degree of maturity, although
the cold water seems to delay the decrease in tail percentage more than maturity.

The general result is definite. The Bay of Islands provides conditions suitable
for the Arctic type, the lower part of the St. Lawrence gulf furnisher a type
approaching that found in the Baltic sea, and the remainder of the region shows the
intermediate type or the typical S. elegans.

I

Distribution.
"Acadia."

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.).

Number.

2

12 m

60
99-144

171
72

50-25 (C.)

1.5-31

25

15

19-31

22-29

28

3 p.m

9 p.m

3 a.m

20-0 (V.)

1

3

100-50 (C.)

1

3O-0 (V.)

0 (T.)

62
4
0

4

150-100 (C.).. .

12-30
20-27
1.5-30
10
1.3-24

46

80-40 (C.)

20

30-0 (V.)

15

6O-0 (V.)

1

0 (T.)

6-1-7x2

6551—3.3

452

DEPARTMENT OF THE NAVAL SERVICE

"Acadia" — Continued.

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.)

Number.

6

6 a.m

45

40-0 (V.)

12-26

8

0 (T.)

10-23

9

7

12m

12 m

108
50

0 (T.)

c. 15
6

2

8

50 (?)-0 (V.)

12

17-25

11

0 (T.)

25

9

6 p.m

104

25-0 (V.)

16

0 (T.)

0

10

9 p.m

732

0 (T.)

17 & 20

2

11

12 m.n

over 2,000

70-0 (V.)

12 & 13
15-20

2
6

0 (T.)

21

1

12

6 a.m

over 2, 000

100-0 (V.)

14
19

1

3

20-30

41

0 (T.)

27

1

13

9 a.m

over 2,000

70-0 (V.)

11-24

6

14

3 p.m

over 2,000

200-0 (V.)

20

1

9 p.m

over 2,000

0 (T.)

0

15

100-0 (V.)

20

1

0 (T.)

0

16

3 a.m

over 2,000

200-0 (V.)

30

1

0 (T.)

15 & 19

2 seen

20

12 m. n

90

0 (T.)

11-26

35

? 23

12 m

99

70-0 (V.)

0 (T.)

4

2
0

25

6 p.m

122

120-0 (V.)

10(?)-0 (T.)

11-30

30
0

26

12 m. n

over 400

100-0 (V.)

11
18-30

1

107

0 (T.)

17-.32

+ +

27

3 a.m

over 400

0 (T.)

15-30

+

i

CANADIAN FISHERIES EXPEDITION, IDUf-lo
' 'Acadia" — Continued.

453

Station Xo.

Hour.

Depth
(metres).

Depth of H;iul (metres).

Length (mm.)

Number.

28

29

30

31

32

34

35

36

38

6 a.m.
12 m...

3 p.m.

9 p.m.
12 m. n

9 a.m.
12m...

3 p.m.

6 p.m.

9 p.m.

over 400

57

i:6

82

153

circa 360

circa 450

226

62

170

100-25 (C.)..

0 (T.)..

55-0 (V.)..

0 (T.).,

120(?)-0 (V.).

0 (T.).

75(?)-0 (V.)..

0 (T.).

100-25 (C).

0 (T.).

100-0 (V.).

0 (T.).

125-25 (C).

0 (T.).

100-15 (C).

0 (T.).

60-20 (C).

60-0 (V.).

20-0 (V.).

0 (T.).

150-0 (V.).

100-0 (V.).

0 (T.).

14-28

15-25

17&22

21

12-31
c. 20
14-30
15-32
16-34

14-32

15-24

26

18

8-17
20-30

4-10

8-16

20-30

8-5 & 14

20-27

5-19
20-23

7-19
20-30

5-19
20-31

5-16
21-22

100

X

2

0

1

0

28

X

130

c. 50

28X5

0

102X2

c. 15

1

1

12

120

31X5

120

190

+ +

X

22+15X10

115

70+63X10

104

+

X

6551—334

454

DEPARTMENT OF THE NAVAL SERVICE
"Acadia" — Continued.

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.

Number.

39

12 m. n.

40

3 a.m.

47

6 a.m.

12 m.

49

50

3 p.m.

9 p.m.

12 m. n.

95

134

140

248

126

151

131

100-0 (V.

25-? (V.).

0 (T.).

125-0 (V.) I..
125-0 (V.) II.

0 (T.).
125-0 (V.).

90-0 (V.)..

0 (T.)..

270-0 (V.)..

45-0 (V.)..

0 (T.)..,

125-0 (V.) I.

0 (T.).
145-55 (C).

145-0 (V.).

55-0 (V.).

0 (T.).
12.5-55 (C).
125-55 (C).

7-18
20-30

6-12

7-15
20-26

7-14
20-30
12-16
20-25
15
20-30
small

8-19
20&22

8-19

20-30

7-12

9-20

23-31

6-13

11-13

12-20

21-26

9-17

9-20

21-28

9-14

7-5-20

7-15

5-14

11-19

21-25

28X10

35

30X5

18

7
+
X

4
12

2
11

?

122+2X10
2

c. 100

0

7

0

0

82X5

175

6

+

3X5

225

9

35X5

124X3

8

27X5

164

+

76X5

257

3

CANADIAN FISHERIES EXPEDITION, 1914-15
' 'Acadia ' ' — Continued.

455

Station No.

Hour.

3 a.m.

6 a.m.

9 a.m.

3 a.m.

6 a.m.

9 a.m.
12 m...

12 m.

6 p.m.

9 p.m.

Depth

(metres).

99

95

over 1 , 000

45

99

61

53

90

63

Depth of Haul (metres).

125-0 (V.

0 (T.)...,

90-0 (V.) II.

0 (T.)....

90-0 (V.)....

0 (T.)...
270-0 (V.)...
125-0 (V.)...

0 (T.)...
45-0 (V.)...

0 (T.)...
90-0 (V.)...

0 (T.)...

0 (T.)...
55-0 (V.) II.

0 (T.).
55-0 (V.).

0 (T.
110-0 (V.

90-0 (V.).

0 (T.)...
55-0 (V.) II.

Length (mm.)

10-17

9-19

28

8-20

13-20

13-18

8-13

13-15

10-11

30

0 (T.).

6-12-5

10-14

13

small

4-10

7-9

10-19

7-9

8-16

20-25

6

5-17

18-19

21-33

5-15

19

22-36

6-11

12-14

6-14

25-29

7-14

Number.

86X5

96

1

+ +

9

14

7X5

13

X

2

0

0

21X10

+

1X5

X

X

18X10+8X40

137

XX

44-1-31X15

4

X

30+41X4

3

50

75+50X5

1

16

+ +

X

90X4

3

+ +

456

DEPARTMENT OF TEE NAVAL SERVICE

"Acadia" — Continued.

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.)

Nuinbcr.

67

68

69

72

76

79

80

81

82

12 m.n.

3 a.m.

9 a.m.

3 p.m.

3 a.m.

12 m.

3 p.m.

9 p.m.

9 p.m.

198

53

68

over 1,000

over 1,000

360

168

60

60

190-0 (V.).
90-0 (V.).

0 (T.)...,

45-0 (V.) II.

0 (T.)...,

5-0 (T.)...,

60-0 (V.) I..

5-0 (T.)...,

c. 20-10 (T.)...

325-0 (V.)...

55-0 (V.).

c. 20-10 (T.).

270-0 (V.).

c. 20-10 (T.).
325-0 (V.).

55-0 (V.).
14.5-0 (V.).

55-0 (V.).

c. 20-10 (T.).

55-0 (V.).

c. 20-10 (T.)..

55-0 (V.) I.

c. 20-10 (T.)..

8-15
20-34

8-14
21-28

8-15

8-20
10-13
10-12
11-14

11
18-20

11-18

20-24

13-16

6-11

8-15

21

6-9

8-11

9-18

21-30

7-5-18

20 & 22

8-15

17

6-13

10-16

22

10-15

9-14

12

109X10

20

c. 100+184X5

10+2X5

+ +

63

6

6

4

0

0

1

3

0

0

8+4x4

12

XX

33X10

16

1

18

29X20

82X4

15

131X4

2

+ +

X

44X10

201

1

+ +

7X4

1

CANADIAN FISIIERIHS KXrKDlTlOX, nil.',-15

457

"Acadia" — Continued.

Station No.

Hour.

Depth

(metres).

Depth of Ihuil (metres).

Length (mm.)

Number.

83

84

85

6 a.m.

9 a.m.

12 m.

3 p.m.

6 p.m.

89

9 p.m.

172

60

over 400

over 400

331

130

132

160-0 (V.)..

55-0 (V.)..

c. 20-10 (T.)..

55-0 (V.) I

c. 20-10 (T.)..

270- 0 (V.)..

55-0 (V.)..
c. 20-10 (T.)..

270-0 (V.)..

55-0 (V.)..

c. 20-10 (T.)..

290-0 (V.)..

55-0 (V.)..

c. 20-10 (T.)..

110-0 (V.)..

55-0 (V.)..

c. 20-10 (T.),.

115-0 (V.)..

55-0 (V.)..

e. 20-10 (T.)..

8-15
17

20-29

7-15

17 & 19

21-24
7-15
9-15
8-14
8-14
19 & 20

25-30

8-16

15

20-30
7-11

12-19

21-26
6-16
7-15
7-10

12-19

23-27

6-9

6-5-17

6-15

17

6-15

6-14

6-15

6-14

22-34
6-14

20-29
6-14

20-29

14X40

1

8

90X4

2

3

+

21X5

+ +

12

2

9

11

X

X

24X10

100

9

9X10

X X

6X10

29

8

5X5

43

+

X

92

86

+ +

19+107X5

124

113X5

61

+

4

458

DEPARTMENT OF THE NAVAL SERVICE

"Acadia' ' — Concluded.

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres).

Length (mm.).

Number.

90
91

12 m.n

(?)

c. 60
c. 45

c. 20-10 (T.)

45-0 (V.)

11-2

20-30

7-13

X
c. 100
17X20

'Princess."

10

11

15

16

17

9 a.m.

3 p.m.
12 m...

9 a.m.

12m...

3 p.m.

9 p.m.

12 m.n.

6 a.m.
9 a.m.
9 a.m.
12 m...
6 p.m.

45
20

32

57

80

80

over 200

over 200

48

over 250

130

. (?)

(?) ...

(?) ...

20-0 (V.

0 (T,

30-0 (V.

0 (T,

60-0 (V

0 (T,

80-0 (V,

0 (T.

80-0 (V.

40-0 (V.

0 (T,

100-0 (V.

80-0 (V.

0 (T.

100-0 (V.

0 (T.

50-0 (V.

0 (T.

80-0 (V.

0 (T.

100-0 (V.

0 (T.

100-0 (V.

100-0 (V.

0 (T.

II

14
11-22
11-22
c. 15

16

4-6

6

4-5

6

c. 6

17-27

28

10

15-26

15-30

15-30

15-30

25-33

15-18

25-30

11-14

16-31
28
21

1

22

c. 25

X

1

0

7X5

0

2

5X6

2X3-5

X

13

1

1 seen

c. 40

21

23

C.30

30

3 seen

9

0

4

0

26

1

1

0

0

CANADIAN FISHERIES EXPEDITION, 1D1J,15
"Princess" — Continued.

459

Station No.

Hour.

Depth
(metres).

Depth of Haul (metres).

Length (mm.).

Number.

18

19

20

21

23
24

25

26

29

30

31

32

9 p.m

3 a.m

6 a.m

9 a.m

3 p.m
9 a.m

12 m..

3 p.m .

6 a.m.

12 m.

3 p.m.

6 p.m.

63

81

over 200

over 400

115
40

68 (?)

39

32

66

65

87

50-0 (V.)...

0 (T.)...

80-0 (V.)...

0 (T.)...

100-0 (V.)...

0 (T.)...

100-0 (V.)...

0 (T.)...

100-0 (V.)...

35-0 (V.) I.

35-0 (V.) II.

0 (T.)...

60-25 (C.) I..

60-25 (C.) II.

60-0 (V.) I..

60-0 (V.) II.

0 (T.)....

40-0 (V.) I..

40-0 (V.) II.

0 (T.)....

20-0 (V.)....

c. 20- 10 (V.)....

60-0 (V.)....

30-0 (V.).

c. 20-10 (T.).

60-0 (V.).

30-0 (V.).

c. 40-0 (T.).

80-0 (V.).

30-0 (V.).

c. 40-0 (T.).

23

19-32

15-32

17 & 22

15-32

16

20-31

16

c. 4

20-30
20-30

20-32
7
17-20
15-25

5-13

10-21

.small

6-15

small

3-11

6-9

2-8

5

10 & 15

6-8

1

0

55X4

0

67

2 seen

176

1

14

1

4

0

14

24

22

35

1

5

12

0

23X5

0

15

9X5

3X5

X

23X5

11

X

2X10

2

16

X

460

DEPARTMElSiT OF THE N^VAL SERVICE

"Princess' ' — Continued.

Station No.

Hour.

Depth

(metres).

Depth of Haul (metres)

Length (mm.)

Number.

33

9 p.m.

34

12 m. n.

35

6 a.m.

36

37

9 a.m.

12 m.

38

39

6 p.m.

9 p.m.

40

12 m. n.

405

over 350

75

180

284

80-0 (V.).

30-0

c. 40-0

130-0

30-0

c. 40-0

130-0

30-0
c. 40-0

60-0
c. 40-0

(V.).
(T.).
(V.).

(V.).
(T.).
(V.).

(V.).
(T.).
(V.).
(T.).

80-0 (V.

30-0

c. 40-0

130-0

40-0

c. 40-0
130-0

40-0

c. 40-0

70-0

30-0

(V.).
(T.).
(V.).
(V.).

(T.).
(V.).

(V.).
(T.).
(V.).

(V.).
e. 40-0 (T.).

10-18

20-30

7-26

12-19

20-29

9-28

20-30

8-20

20-26

10-20

10-17

6-16

6-16

30

6-12

8-20

25 & 29

6-17

6-21

6-16

&-15

6-16
6-15

20-26

6-14

6-16

6-15

26

small

10-23

26X10

17

164

+

1X10

6

13

17

e. 50

19

23

12+4X4

+ +

28+39X4

+

1

10X4

32

2

42

+

120+12X4

64

+
108+13X4

7
24
+
59

1
76
22
+

CAXAfHAX FlsllKlllEfi EXPEDITION, 191 ',-13
' 'Princess" — Continued.

461

Station No.

Hour.

41

42

43

44

45

46

47

48

49

3 a.m.

9 a.m.

12 m.

3 p.m.

3 a.m.

6 a.m.

9a.i

12 m.

6 p.m.

1? m. n

Depth

(metres) .

189

90

265

157

375

over 400

over 400

171

Depth of Haul ("metres).

130-0 (V.)...

30-0 (V.)...

c. 40-0 (T.)...

100-0 (V.)...

30-0 (V.)...

o. 40-0 (T.)...

130-0 (V.) I..

30-0 (V.) I..

30-0 (V.) II.

c. 40-0 (T.)...

130-0 (V.)...

30-0 (V.)...

130- 0(V.)...

30-0 (V.).

c. 40-0 (T.).
130-0 (V.).

30-0 (V.)..

c. 40-0 (T.)..

130-0 (V.) I.

3O-0 (V.).

c.40-0 (T.).

130-0 (V.).

30-0 (V.)...

c.40-0 (T.)...

70-0 (V.)...

30-0 (V.)...

c.40-0 (T.)...

40-0 (V.) I.

c. 40-0 (T.)...

Length fmm.)

6-15

7-15

6-15

7-10

6-12

6-14

6-13

5-9

7

7

6-17

6-16

12-21

24-30

6-20

26

8-20
21-32
8-17
c. 13
5-18
23 & 26
6-15
c. 12
6-18
22-26
6-18
c. 15
6-16
6-20
c. 12
6-20
c. 15

Number.

155
116

+ +

18

26

+ +

49

5

1

11

192X4

64X4

170X8

8

110X8

2

+ +

90X5

13

60X4

X X

110X4

2

102

+ +

80

4

50X4

+

42X10

52X4

+

148X4

+ 4-

462

DEPARTMENT OF THE NATAL SERVICE

Princess " — Continued.

Station No.

Hour.

Depth
(metres).

Depth of Haul (metres).

Length (mm.).

Number.

4

6b
9
10

11
12

13
14
15

19b
23

26

29
36
40
48
49
54

57

58

3 p.m.
3 p.m.
12m..
3 p.m.

b p.m.
9 p.m.

9 p.m.
12 m.n.

6 a.m.

6 p.m.
12 m...

9 a.m.

6 p.m.
6 p.m.
?

6 p.m.
6 p.m.
9 a.m.

3 p.m.

45

c-30

10

39

59
67

39
58
38
90
355

12 m.

389

41
60
38

110

210

50

2-0 (T.).

2-0 (T.).

2-0 (T.).

2-0 (T.).

35-25 (C).

25-10 (C).

10-0 (V.).

2-0 (T.).

2-t) (T.).

3-0 (T.).

3-0 (T.).

2-0 (T.).

2-0 (T.).

340-145 (C).

100-60 (C).

45-0 (V.).

0 (T.).

30-15 (T.).

2-0 (T.).

3-2 (T.).

20-8 (T.).

c-9 (T.),

40-0 (T.).

15-0 (T.).

70-35 (T.).

25-5 (T.).

200-0 (V.).

12

22

19-24

16-26
14

5

3-6

13

10-22

10-26

15

6

20
23-32
15-22

40-0 (T.).

6-10
6-10

10-19
5

11-16

11-16
9-15

27-33
42

10-12

1

1

5

0

32

1

0

1

6

1

c-50

+ +

1

1

0

1

29

5

0

1

1

0

X

X

X

c. 100

1

+ +

+ +

12+51x10

31

1

+

CANADIAN FISHERIES EXPEDITION, IdUflo

463

"Princess "—Concluded.

Station No.

59

64
67
68
69

70

Hour.

12 m..

8 a.m
1

6 p. Ill
3 a.m
.3 p. in

3 p.m

6 p.m
12 m...

6 p.m

Depth
(metres).

275

Depth of Haul (metres).

270-0 (V.).

80-20 (T.).

30-0 (T.).

70-20 (T.).

100-20 (T.).

8-2 (T.).

Length (mm.)

10-16
17-45
11-16
11
10-30
10-.30
13-15

Number.

106X10
70
1X2

+
+ +

+
c- 6

" Prince."

c. 38

e. 100

180

c. 35

c. 35-0 (V.) 1..

c. 35-0 (V.) II.

c. 20-10 (T.)....

0 (T.)....

100-0 (V.)....

4-2 (?) (T.)

180-0 (V.)....

c. 20-10 (T.)

2-0 (T.)....

c. 35-0 (V.)....

15-5 (T.)....

18-30

22-28

18-35
9

23 & 27
26

0

0

41

5

9
0
98
1 seen
0
2
1

464 DEPARTMENT OF THE ^AYAL SERVICE

Vertical.— So many factors are involved in tlie vertical distribution of this species
that a discussion of particular stations is necessary. At No. 33 station 23 in the deep
water off Anticosti island no specimens were obtained in the closing-net haul between
34£) and 145 metres. Between 100 and 60 metres, one specimen 20mm. long and twenty-
nine over 23mm. long were obtained. Between 45 and 0 metres there were five speci-
mens all 22 mm. or under in length, and at the surface none were obtained. These
hauls were made about midday (l-2p.m.). The larger specimens were all below 45
metres, the intermediate specimens above 60 metres but not at the surface. No speci-
mens were in the deep saline water. No small specimens were present.

At No. 33 station 10 off the eastern side of Prince Edward Island in shallow water,
the closing haul from 35 to 25 metres gave thirty-two specimens over 16mm. in length.
The haul from 25 to 10 metres one specimen 14mm. long; and the hauls from 10 to 0
metres and at the surface, none. These hauls were made about 3 p.m. The larger were
in the cold bottom water below 25 metres, and there were none above 10 metres.

In the Bay of Islands at No. S3 station 54 the tow hauls 'which were presumed to
go as deep as 70 metres brought up an abundance ofi this species, but all the individuals
were 16mm. or less in length. At practically the same spot at No. 33 station 55, the
young -fish trawl brought up from the bottom (about 110 metres deep) an abundance
of large individuals (23 to 43mm. in length.) Here again the larger individuals were
wholly confined to the cold bottom water below 70 metres, and there was an abundance
of small individuals above 25 metres. The time of day was between 9 and 10 a.m.

At No. S3 station 57 in the Bay of Islands where the depth was 210 metres with
moderately saline water below the freezing point quite to the bottom, the young-fish
trawl, which was towed along the bottom, brought up an abundance of large individuals
between 21 and 52mm. long. These were thoroughly mixed with typical bottom forms
(shrimps and Amphipods) so that there can be little doubt but that they were near
the bottom. It is at least probable that in the Bay of Islands the larger individuals go
down, into the deepest water, for example, 270 metres at No. 33 station 59. More
definite information is desirable on this point. There would thus be a marked differ-
ence in the vertical distribution depending upon the character of the water. Where
proper conditions of salinity and temperature obtained, the species goes far into the
depths, but if not, it is restricted to the suitable intermediate layers.

As in the case of Euk-rohnia hamata, the hauls made in the Bay ofl Fundy at
Prince stations 1, 2 and 3 showed the effect of the vertical currents due to the tides.
At station 1 where the species was so rare as not to be taken in either of two vertical
hauls, the tows taken near or at the surface yielded 46 large specimens. At stations
2 and 3 it was obtained in numbers in the vertical hauls, but failed to occur in the tows,
except one small individual in the deep tow at station 3.

Vertical currents doubtless explain many of the irregularities appearing in the
vertical distribution elsewhere.

Owing to differences due to this and other factors, it is very difficult to determine
what effect light has on the vertical distribution of this species. If we divide the
twenty-four hours into three-hour intervals, and designate these by their mid-points,
6 a.m. representing from 4.30 to 7.30 a.m., and others similarly, and then put together
the records for each three-hour period, we can to some extent overcome the influence
of the other factors. The stations on the first cruise of the Acadia, at which this
species was obtained, give the following result as to its presence or absence in the
surface hauls: 9 a.m., one negative; 12 m., two negative, 3 positive; 3 p.m., three nega-'
tive, one positive; 6 p.m., two negative; 9 p.m., one negative, two positive; 12 midnight,
four positive; 3 a.m., three positive; 6 a.m., two positive. It is noteworthy that large
numbers were obtained in the surface hauls only for 12 midnight and 3 a.m. From this
we conclude that S. elegans comes to the surface from 9 p.m. to 3 a.m., occurring there

CAXADIAX FISHERIES EXPEDITIOX, nu'rl.j 465

ill uumbers about the middle of that period. From 9 a.m. to G p.m. it seeks a lower
level. The individuals obtained on this cruise were of large size.

The Princess cruise (stations 3 to 26) gives similar results, but the figures require
analysis: 9 p.m. and 12 midnight show many large individuals at the surface (stations
8 and 9; 6 a.m. shows several only (stations 10 and 20). For some reason the single
3 a.m. station (19) is negative. From 9 a.m. to 6 p.m. the stations are negative or
show only small individuals (9 a.m., ICmm. ; 12 midnight, 5-7mm. ; 3 p.m., 6mm.);
but there is a single exception at station IG, where one large individual was obtained.

The specimens from the second cruise of the Acadia (stations 37 to 90) have been
divided into two groups, those under and those over 20mm. in length. The larger group
is represented in surface hauls in only three instances. A few specimens were obtained
in the surface hauls of the first three stations, at 6 p.m., 9 p.m., and 12 midnight. The
largest individuals were obtained at the midnight station. In the deeper tow hauls of
the latter i^art of the cruise, they were obtained in only three instances; occasional in
one at 9 a.m., abundant in one at 9 p.m., and one at 12 midnight.

Those under 20 mm. show a different distribution. Surface hauls : 9 a.m., two
negative, one positive (occasional specimens up to 10 mm. long) ; 12 m., one negative,
two positive (occasional specimens up to 9mm.) ; 3 p.m., one positive (many specimens
up to 13mm.) ; G p.m., two positive (very many specimens up to 19mm) ; 9 p.m., three
positive (very many specimens up to 16mm.) ; 12 midnight, three positive (many
specimens up to 20mm.) ; 3 a.m., four positive (several specimens up to 18mm.) ; 6
a.m., one negative, two positive (occasional specimens up to 11mm.). Deeper tow
hauls : 9 a.m., one negative, one positive (occasional specimens) ; 12 m., one negative,
one positive (occasional specimens) ; 3 p.m., one negative, two positive (many speci-
mens) ; 6 p.m., one positive (very many specimens) ; 9 p.m., three positive (very many
specimens) ; 12 midnight, one positive (many specimens) ; 3 a.m., one positive (occa-
sional specimen) ; 6 a.m., one positive (very many specimens). There is little evidence
of any daily migration of the larger individuals at these stations. They remain almost
constantly in the depths. The smaller individuals come nearer to the surface. They
are less abundant and smaller or entirely absent from 6 a.m. to 3 p.m.

Taking the shallow vertical hauls (30 to 0 metres) of the second Princess cruis'j
(station 27 to 50), we have the following upper limits in size for the individuals
obtained in the several three-hour periods: 9 a.m., 15mm.; 12m., 18mm.; 3 p.m., l(3nim. ;
6 p.m., 20mm. ; 9 p.m., 26mm. ; 12 midnight, 28mm. ; 3 a.m., 20mm. ; 6 a.m., 20mm.
There would seem to be a definite movement of the larger individuals across the 30-
metre line during the twenty-four hours.

As to the effect of temperature on the vertical distribution, we may compare ths
early and late cruises both outside and inside the gulf. On the earlier cruises the
surface water was decidedly colder than on tlie later ones. The Acadia^s cruises show
that outside the gulf in May-June large individuals came in numbers to the surface
during the night, while in July-August tliey were virtually absent. The Princess'
cruises show that inside the gulf in ,lune larger individuals came to the surface than
came above 30 metres in August, for 9 a.m., 12m., 9 p.m., 12 midnight and 6 a.m. This
decrease in the daily vertical migration is doubtless due to the warming of the surface
water.

The facts point to the following conclusions Safjitta elegans is confined to water
of comparatively low salinity, being stopped in its migration into the depths by water
of high salinity. It is affected by light, coming nearer the surface at night. It is
affected by temperature, keeping to the colder water. The young behave differently
from the adults, living in the lighter, warmer surface water. With increasing age it
becomes gradually restricted to the darker, colder water, which is deeper.

466

DEPARTMENT OF THE NAVAL SERYICE

Horizontal. — This species belongs to the subarctic and arctic regions. Along our
coast it is typical of the cold coastal water and is found over practically the whole of
the continental shelf. Its distribution in May-June is shown in fig. 8. Of the entire area
covered, it was absent at only three places ; western part of Northumberland straits
(Princess station 4), north of Anitcosti island (Princess stations 12 to 14) and out in

Fig. 8.

-Distribution of S. e/e>/<ins, May-June 1915. Zones showing frequencies of I to 10, 11 to 100 and 100
and over. Horizontal lines indicate a zone containing none over 10""" in length.

tbe open Atlantic at one of the outermost (Acadia station IT). Its area of abundance
(Corresponded closely with the deeper parts of the coast water, the shallow southern
part of the gulf an dthe shallow banks elsewhere showing only a few or small indi-
viduals. Its great abundance at the mouth of the Laurentian channel and off Banque-
leau at Acadia stations 12, 13, 26, 27, and 28 would indicate the presence there of a
large amount of cold coastal water. At the remainder of the stations off the con-
tinental shelf, it was present in small numbers or altogether absent.

CANADIAN FisHEliIKH EXPEDITION, 19tJrl5

467

The distribution in July-August is represented in fig. 9. The large individuals
(those above 20mm. in length are represented by vertical lines) are more restricted
to the deeper parts of the coastal water, and in the northern part of the gulf they are
few in number or altogether lackin.g even in the deep water. We again see
them abundant off the mouth of the Laurentian channel on the southern
side, at Acadia station 70, indicating the presence there of coastal water, tliat

Fig. 9— Distribution of S. dcfiium, .Tiily-August 1915. Horizontal line.s indicate individuals under
20 mm. in length and vertical lines those over 20 min.

has doubtless come from inside Banquereau. Tlie absence of large individuals
on the banks where warmer water conditions prevail than in the spring-
is important. The small individuals (represented by horizontal, lines) are
generally present over the whole of the continental shelf, and pass out with the coastal
water from the mouth of the Laurentian channel. In two places they are absent, and
for different reasons. In Northumberland straits there were none, perhaps because
this area is too far from the places where the adults occur. In the Bay of Fundy.
among 156 specimens there was only one individual under 18mm. in length, and that

6551—34

468 DEPARTMENT OF THE NAVAL SERVICE

at Prince station 3 in the mouth of the Bay. There can be no doubt that the absence
of warm, brackish surface water in this part has prevented their development, the
Bay of Fundy being a distinctly unfavourable breeding place,, although quite suitable
for the adults, as large numbers of them were found. In the Bay of Islands fjord the
conditions appear to be ideal for both the old and the young, the icy bottom water
containing an abundance of the adults and the warm brackish surface water an
abundance of the young. There is therefore a sharp contrast between the conditions
in: (1) the Bay of Islands, (2) the lower part of the gulf, and (3) the Bay of
Fundy. In the first the conditions are suitable for both adults and young, in the
second suitable only for the young and in the third suitable only for the adults.

The virtual absence of small individuals in the Bay of Fundy is important, as
indicating the lack of suitable conditions for the breeding of species that require
quite warm water of comparatively low salinity for at least the early stages of develop-
ment. Many fish of economic importance have eggs and young larvae at the surface
that would be affected by this. Further investigation of the Bay of Fundy is needed.

The hauls lacking young Sagitta elegans were made in September. Prof. J. P.
^VfcMurrich informs me that in a series of tow-nettings taken regularly in Passama-
quoddy bay from October, 1914, to May, 1915, only two small Sagittoe were obtained,
and these at the mouth of the St. Croix river on October 29, 1914. This is a spot
with strong tidal currents^ where forms brought in from without would appear, if
they did appear anywhere. The nets used were more suitable for talking younj^
Sagittce than older ones, and yet ten large individuals from 23-5 to 32-5 mm. in length
were taken in a haul on January 1, 1915.

The centre of abundance during the earlier cruises (May-June) is shown in
fig. 8. Stations at which more than 100 individuals were obtained in the deep vertical
haul occur in an area represented by the most closely placed lines. This area occupies
the Laurentian channel from the centre of the gulf outwards to slightly beyond the
mouth. Two tongues extend from it to the southwest. One just outside Cape Breton
island and the other just outside Banquereau. These may signify the directions in
which the currents are carrying the abundant schools. On the later cruises the centre
of abundance of the larger individuals is at the lower end of Nova Scotia (as shown
in fig. 10). This part of the region was not investigated on the first cruise, but it is
at least probable that the currents have during the intervening two months carried'
large numbers from the Laurentian channel down along the coast, and thus depopulated
the northern part of the area. This is all the more probable because the conditions
at the lower end of Nova Scotia do not appear to be as suitable for the large individuals
as those of the intermediate water in the Laiirentian channel.

Another centre of abundance is seen among the banks north of Sable islaiid
at Acadia station 89 where 124 specimens were obtained in the vertical haul. Their
presence near the surface was demonstrated by the taking of sixty-one in the haul
from 55 metres to the surface, and by tlie large number ol>tained in the tow. This
zone apparently extended to station 90, where many were obtained in the tow, but
where no vertical haul was made. The neighbouring station (66) showed very few
large individuals, but at station 65 ofl" Cape Canso, fifty were obtained in the deepest
haul. The distribution suggests that the pressing-in of the boreal water over the
banks south of Sable island has tended to separate the zone of abundant ^S*. elegans
into two parts, one north of Sable island and the other at the lower end of Nova Scotia.

At Acadia station 77 at the mouth of the Laurentian channel no vertical havl
was made, but since the deep-water form Eul-rohnia hamafa was obtained in the tow
haul and no S. eleqanst. it is practically certain that the. latter species was absent. This
is significant, indicating almost pure boreal water at that point between two stations
where coastal water was present. This boreal tongue extends into the Laurentian
channel on the north side. Farther up the channel it is covered with coastal water
(stations 85 and 9'^).

CANADIAN FlSUEIilKti KXrEDlTION, 191/rlo

469

The distribution of the large individuals in July-August shows that they have
retreated from the shallower banks, also from the lower part of the gulf and curiously
enough also from the deep northern part of the gulf. Between Anticosti island and
the north shore they were entirely absent in June but present in August. The gcnoral
circulation in the gulf has doubtless been responsible for this, carrying them around
and then out through Cabot strait.

Fig. 10.— Distribution of ,S'. clemns (those over 20""" in length), .July-August 1915. Zones showing
frequencies of 1 to 8, 9 to 90 and 90 and over pt-r station.

The retreat inshore of the species during the summer from the open Atlantic is
shown by its absence beyond the continental shelf during the late cruise, except at the
mouth of the Laurentian channel, while during the early cruise it occurred at the
outermost stations (except Acadia station 17), though in small numbers. In some
place.=s on the late cruise it was pushed well back from the edge of the shelf, particularly
in the southern part.

During the June cruise the western side of the lower part of the gulf contnircd
only small individuals, 6mm. or loss in length. This is shown by the horizontal lines
6551— 34J

470 DEPARTMENT OF THE NAVAL SERVICE

in fig. 8. This is the beginiiing of the condition that in the August cruise was found
over practically the whole of the lower part of the gulf. It is interesting that this
change has spread from west to east in the direction of the Gaspe current.

The presence of two large individuals of this species in the boreal oceanic water
at Acadia station 54 does not, I think, indicate that there has been an outflow of
coastal water at this point, but rather that individuals carried into the boreal water
■ by the tongue of coastal water that comes out of the southern side of the Laurentian
-channel, have been transported in the boreal water along the side of the continent past
Sable island along the course shown by the distribution of E. hamata (fig. 12). During
May-June the tongue of coastal water actually extended from the channel mouth to the
southwest for a considerable distance, as found at Acadia station 12 (see fig. 8), with
boreal water on either side. We can readily believe that early in the year such a
tongue extended as far to the south as Acadia station 54 at least, and from that point
passed up over the banks to connect with the coastal water off Halifax. In July-
August this connection of the coastal water outside Sable island had been severed in
the middle and only the ends left.

The large amount of boreal water occurring on the shelf off Halifax accounts for
the few large *S^. elegans found at stations 47, 48, and 51.

On the New England coast, Bigelow (1915, p. 299) has found the species extending
in the coast water as far south as Long island.

In making a comparison of the distribution of this species on the two sides of the
Atlantic, there arises a doubt as to the identification of the European specimens.
According to Eitter-Zahony this species has been confused with S. hipnnctata. If the
European records of the latter species are referable to *S'. elegans, we have the .latter
species confined to the epiplankton and occurring down to 100 fathoms off the Irish
coast (Ritter-Zahony, 1910, p. 2) with the younger stages in the upper layers, and the
older stages in the lower. Its outer limit of distribution is not indicated.

Apstein (1911, p. 171) describes its occurrence throughout the North sea and
neighbouring waters, going below 300 metres in depth in the Skager-Eack, and in the
Baltic not usually occurring near the surface but only in the deeper water where more
saline conditions prevailed; sometimes only on the bottom below 85 metres (Danziger
Bucht). The Arctic form occurred only in the Kattegat and Skager-Eack, and was
confined to the deeper layers, coming near the surface only in winter.

There is a definite agreement between the distribution on the two sides of the
Atlantic — its general occurrence in the coastal waters and usually confined strictly to
the epiplankton; its -rarity and restriction to the deeper layers in areas where low
salinity and high summer temperatures prevail, as in the lower St. Lawrence gulf
region and in the Baltic ; and the development of a small type in an extensive shallow
enclosed area and of a very large type where the true coastal water is deep. One
difference is worthy of note: it has (at least in summer) a sharp outer limit on the
American coast, where as on the European coast none has been shown, indicating that
there is not there the sharp distinction between oceanic and coastal water that is met
with on this side of the Atlantic.

CA\ADIAX FIfiHERIES EXrEDITlOy, 191>,-1')

471

(/() Pterosagilla draco (Xrohn).

" Acadia."

Station Xo.

Hour.

Depth

(metres).

Depth of Haul (metres)

Length (mm.).

XuinlxT.

41

44

G a.m

9 p. Ill

360

over 1,000

over 1,000

200-0 (V.).

100-0 (V.).

0 (T.).

270-0 (V.)

0 (T.).

32.S-0 (V.).

5.5-0 (V.).

c. 20-10 (T.).

.5-9 • .5

Only six specimens were obtained, four of which were in the surface, haul at
station 44. Its distribution is shown by the horizontal interrupted lines in fig. 1. It
is a tropical surface form. Bigelow obtained it iu July-August, 1913, at his outermost
southern stations south of cape Cod. It is noteworthy that it occurred at three of
the five stations at which Sagitta enflata was found, and that four of the six specimens
came from the onlj^ station where 'S'. enflata was abundant. Fowler notices this agree-
ment in the general distribution of the two species (1906, p. 76).

Fowler gives its most northerly record as 41° 36' N, 56° 18' W. (Strodtmann).
Its occurrence at Acadia station 75 (43° 30' N., 56° 43' W.) extends its known northern
limit. These two tropical species (for both of which new northerly records are now
given and for our waters, their previous northerly records having also been from our
waters) come much farther north on this side of the Atlantic than on the European
side, where they only reach the latitude of the Mediterranean, thus harmonizing in
a general way with the distribution of salinities and temperatures (see Hellaud-IIau-
sen in Murray and Hjort, 1912, pp. 227 and 297). Strodtmann, who studied the
Chaetognaths obtained by the Plankton-Expedition in the North Atlantic, which
included a series of stations both north and south of the Newfoundland banks, con-
siders that these two species characterize the true region of the Gulf Stream (1892,
p. 369) as opposed to the Labrador current and the northeastern branch of the Gulf
Stream.

Their distribution indicates that the surface water of the Gulf Stream presses
in much nearer the continental shelf at the lower (southern) end of our range than
elsewhere.

472

DEPARTME^'T OF THE ^'AVAL SERVICE

(i) Eukrohnia hamata (Mubius). Fig. 11.
1911. Ritter-Zahony, p. 30.

Fig. 11. — Eukrohnia iiaiaata. x 4.

The range in size is from 7 to 35mm. long. The latter is near the upper limit of
its length, and yet in none were the ovaries mature, although in some of the larger
individuals the seminal vesicles were distinct. It may be doubted whether it breeds
in our area, unless in the deeper parts of the outer waters, which we did not investigate.
As it is typically a deep-water species, except in polar waters, the absence of mature
individuals is not to be wondered at.

C'.4.Y.4/>/.i A FISH !■:/>'/ i:s i:\ri:niTi(>y\ lui'rU

473

DISTRIBLTION.
"Acadia."

Station Xo.

26

27
28

35

47

18

50

Depth

(metres).

over 2, 000

over 2,000
over 2,000

over 2, 000

over 2,000

over 2,000

122

over 400

over 400
over 400

c. 450

140

248

151

Depth of Haul (metres).

60-0 (V,
0 (T.

70-0 (V,

0 (T.

70-0 (V.

200-0 (V.

0 (T.

100-0 (V.

0 (T.

200-0 . . .

0 (T.

200-0 (V.

0 (T.

120-0 (V.

0 (T.

100-0 (V.

0 (T.

0 (T.

100-25 (C.

0 (T.

125-25 (C.

0 (T.

125-0 (V.

90-0 (V.

0 (T.

270-0 (V.

45-0 (V.

0 (T.

145-55 (C.

145-0 (V.

55-0 (V,
0 (T,

Lenglit fmm.).

12

10-14
9-20

20
20

e. 15
21

8-13

10-12

10-22

c. 20
10-16

1.5-19

8-14

14

10

15

10-14

IS & 21

Xuiiiher.

10X10

0

1

1X2

1

1 seen

3K10

0

3

1

12

X

XX

6

0

3X2

0

8

X

0

1

0

0

2X5

2

2X5
2

0
0

474

DEPARTEIENT OF THE NATAL SERVICE

"Acadia" — Continued.

Station No.

Depth
(metres).

Depth of Haul (metres).

Length (mm.). Number.

52

54

57

58

67

70

72

74

76

99

over 1 , 000

over 1,000

over 1,000

187

over 1,000

over 1,000

over 1,000

over 1,000

over 1,000

90-0 (V.) II.
0 (T.)....
270-0 (V.)....
125-0 (V.)....
0 (T.)...,
270-0 (V.)....
90-0 (V.)....
0 (T.)....
270-90 (C.) ..
90-0 (V.)...
0 (T.)...
180-55 (C.)...
150-0 (V.)...
55-0 (V.)...
0 (T.)...
190-0 (V.)...
90-0 (V.)...
0 (T.)...
325-0 (V.)...
55-0 (V.)...
c. 20-10 (T.)...
325-0 (V.)...

55-0 (V.).

c. 20-10 (T.).

325-0 (V.).

55-0 (V.).

c. 20-10 (T.).

270-0 (V.).

c. 20-10 (T.).
c. 20-10 (T.).

12

9-16

9-11

10-13

12

24

7-15

7-13
17-23
11-13

8-12
15-21

12
14-20

17
24

1
0

29
0
0
5
0
0

22
0
0
1
0
0
0

1

0
0

54
0
0

60

12
3
0

31
2
0
0
11X4
9
0
1
1

CWADIAX FISHEh'IES EX/'EDfr/OX, Wl',-15
"Acadia" — Continued.

475

Station Xo.

Depth

(metres).

Depth of Haul (metres).

Length (mm.).

Number.

85

87

360

over 400

325-0 (V.).

55-0 (V.).
270-0 (V.).

over 400

55-0 (V.).

c. 20-10 (T.).

270-0 (V.).

.331

.5.5-0 (V.).

c. 20-10 (T.).

290-0 (V.).

55-0 (V.).
c. 20-10 (T.).

.5-14

10-23

12

7 -.5-10

10-19-5

10-20

10-17

8-10

13-23

10-13

c. 12

8-11

11-22

12-19

14 & 15

10X10

43

1

4X40

27

17

X X

14X10

28

5X10

1 seen
3X10

19
5

2 seen

34

"Princess'

405

130-0 (V.).

30-0 (V.).

c. 40-0 (T.).

18-28

"No. 33'

23

355

340-145 (C).

100-60 (C).

45-0 (V.).

0 (T.).

10-13
22 & 35

"Prince'

c. 38

180

c. 35-0 (V.)I..

c. 35-0 (V.) II.

c. 20-10 (T.)....

0 (T.)...,

180-0 (V.)..,

c; 20-10 (T.)...

2-0 (T.)...

19-21

24 & 26

476 DEFART3IENT OF THE NAVAL SLRTICE

Vertical. — At station 23 of the cruises of tlie trawler No. 33, three vertical hauls
were made frora various depths with the closing net. This station is well up in the gulf
of St. Lawrence, and so well away from places, where mixing is going on which might
through vertical currents vitiate the results. Six specimens of this species were
obtained between 340 and 145 metres, and none between 100 and 60 metres and from
45 metres to the surface. On the cruises of the Princes^ in the gulf, numerous hauls
were made in the deeper parts with open vertical nets from 100 or 130 metres, and at
only one station was this species obtained. Its vertical distribution for the gulf may
be considered to lie below 130 metres.

In the Bay of Fundy at station 3 of the Prince, two specimens were obtained in
the open vertical net from 180 metres and none in the tows above 20 metres in depth.
Yet at station 1, although none were obtained in two open vertical hauls from the
bottom (showing the rarity of the &i)ecies there), three specimens were obtained in the
tow haul about 20' metres in depth and one in a haul made at the surface. This latter
station was in the Friar Roads between Eastport and Campobello island. The tides
here are of such magnitude that the water forms whirlpools and the " boiling "' up of
the deep water to the surface can be seen constantly. These vertical currents are
certainly responsible for bringing this deep-water species to the surface at this point.
Jiist outside Campobello island at station 2, both the vertical haul from about 100
metres up and the tow hauls failed to secure any specimens of this form, showing that
it was some distance down.

Its presence at or near the surface at Acadia stations 15, 16, 25, 26 and 27 indicates
that there were strong vertical currents at the mouth of the Laurentian channel on the
first cruise of the Acadia. On the second cruise it was at or near the surface only at
stations 77, 85, 86, and 87 at the mouth and some distance up the Laurentian channel-
showing strong vertical currents in about the same area. The data from the last three
stations are interesting. At stations 85 on the north side of the channel, where S.
serratodentata and S. maxima were most abundant, we find this species coming near the
surface in fair numbers (20-10? metres, rather many) and many obtained in both the
shallow and deep vertical hauls. At 86 in the middle of the channel, while very many
were obtained from both vertical hauls, only one was seen in the material taken by the
tow haul. At station 87 on the south side of the channel, while a fair number came up
in the deep vertical haul, the shallow vertical haul yielded five only, and a solitary
specimen was observed in the tow. This species comes aiearer to the surface as we pass
to the north across the channel, indicating greater vertical currents on the north side-
or a greater influx of the cold deep boreal water, from which the vertical currents may
bring the species to the surface. There is, of course, the possibility of the species
coming to the surface of itself under changed conditions, perhaps of salinity and
temperature, as it does in polar regions.

The vertical distribution seems to vary with the region, but these details may
more appropriately be considered in connection with the horizontal distribution.
Suftice it now to say that it did not appear in the outer and southern stationsi (stations
41 to 46, 56, 75), the hauls, one of which was fi-om a depth of 375 metres, apparently
being too shallow, the cosmopolitan distribution of the species making it fairly certain
that it was present but at lower levels. Fowler (1906, p. 73) refers it to the epiplank-
ton (usually young specimens) north of 47° IST., and to the ^nesoplankton in tropical
and sub-tropical waters. Michael (1913, p. 35) states that his data suggest " that the
region of maximum abundance is in the neighbourhood of 250 fathoms for the San
Diego region."

The records are too fragmentary to show whether or not daylight affects the
vertical distribution.

Horizontal. — This species is cosmopolitan, being found in all seas, and it extends
to both tliei farthest north and the farthest south- As it is a deep-water form in low lati-
tudes, if we consider only the proper layers of the sea (the part explored by our nets),

CANADI.W FISUEHII.s EX I'EhlTION, JDUf-lS 477

this species is characteristic of arctic and antarctic seas. In our region it may be con-
sidered the typical form of the deep boreal water next the banks. On the first cruises
during May and June it occurred at Acadia station 5, inside Sable isUnid, generally
in the deep water examined off the mouth of the Laurentian channel, up the channel
in Cabot strait (Acadia station 35) and far up the channel in the deep water between
Anticosti and Gaspe (No. S3 station 23). It is doubtless present in all the central
deep parts of the St. Lawrence gulf. Our other hauls in this area were too shallow
to obtain it. The distribution in July and August, as shown in fig. 12, was similar,
with the gulf hauls again too shallow except at one station (Princess station 34). It
is again present in the Laurentian channel and at its mouth, as well as along the outer
side of Sable island bank and in the deep water between that bank and Halifax and
in the Bay of Fundy. In both cruises it is definitely absent over the banks south of
Newfoundland, over the banks north of Sable island (rare in the gullies or fjords —
Acadia station 67, one specimen), as well as in the shallow parts of the gulf and close
olong the Nova Scotia shore. It is therefore absent from the cold coastal water. This
is well shown by its absence in the Bay of Islands (No. 33 stations 57 and 69), where
there is a depth of as much as 150 fathoms, but with water of low salinity and low
temperature all the way to the bottom.

Its outer limit of distribution was not reached on the May-June cruises, (though
it was rare at stations 15 and 16) but in the July- August cruises it was plainly
demonstrated. It failed entirely at the typical Gulf Stream stations (Acadia stali<.ns
41-(45, 56, and 75) except the most northerly one (74), as well as at some of the inter-
mediate southern stations (Acadia stations 38-40 and 46). The hauls of the Prince
in September show that it occurs in all the deeper parts of the Bay of Fundy. Bigelow
found it in July-August, 1913, in all the deeper parts of the gulf of Maine and under
the edge of the Gulf Stream, but never at the surface.

The absence of any connection being shown between its distribution off the Nova
Scotia coast and in the gulf of Maine is apparently owing to the prcssino- in of the
Gulf Stream close against the continental shelf (Acadia station 41), and also owing
to the hauls at this point not being deep enough to get below the Gulf Stream. Tbis
phenomenon of the sinking of the species to lower levels as we pass out inln tb" Gelt
Stream is very well shown in the records. At Acadia station 72, three individuals were
obtained in the shallow vertical haul (55-0 metres), and 72 in tlie deep vertical haul
(325-0 metres). At station 74 there were none in the shallow haul, but thirty-three in
the deep haul. At station 75 there were none in either haul. At stations 52 and 58
on the continental shelf it was obtained in hauls from 90 and 180 metres, respectively.
At stations 54, 55 and 57 it occurred in fair numbers in the vertical hauls from 2'70
metres, but not in the vertical hauls from 125 and 90 metres. And at station 56 it
was not present even in the deep haul from 375 metres. The gradation in size as we
pass into warm water is equally distinct. For the same depth, the individunl-s beenn^e
distinctly smaller as we pass to warm water. At station 72 the proportion of small to
large (those under and those over 15mm.) was 5 to 1. At station 74 for a similar haul
it was 15-5 to 1, and at the same time the maximum size changed from 23mm. to 21mni.
Off Sable Island bank the stations taken in order of their nearness to the continental
shelf show the followintr for similar haids (270-0 metres) : Station 54. twentv-nine
specimens with a maximum size of 16 mm. ; station 57, twenty with a maximum of
13 mm.; station 55, five with a maximum of 11 mm.; and station 56, none. There is
a decrease in maximum size as well as in the number taken. Although the records
are framentary this species is seen to resemble others in that the younger individuals
are to be found in the upper, warmer water, as described by Broch and Fowler for this
species.

The records are too incomplete to show where the centre of abundance was during
the earlier cruises, but it must have been north of Acadia station 16. between that
point nnd tlie eontiiuMital shelf, as shown by the numbers at stations 14 and 17. the

478

DEPARTMENT OF THE yiVAL SERVICE

only two where deep hauls were made. On the later cruises the centre of abundance
(as shown by the closely placed lines in fig. 12) was definitely in the northern oceanic
water just south of the Newfoundland banks. It decreased in quantity to the north.

Fig. 12. — Distribution of E. hamata, July- August 1915. Zones showing frequencies of 1 to 20, 21 to 75

and 75 and over per station.

west, and south. The agreement with the distribution of S. maxima is very evident.
They both belong to the deeper part of the boreal oceanic water and show its extension
up the Laurentian channel and to the south along the outer side of the continental
shelf and to some extent over the banks, but diminishing in amount in each direction.
The two species differ in that S. m,axima can not endure as much of a decrease in
salinity as can HJ. hamata, and does not extend as far up the Laurentian channel or
over the banks as the latter species. It can, however, endure an increase in salinity
better than E. hamata, as it occurs in the outer Gulf Stream stations, where the latter
is absent on the later cruise though present on the earlier. High temperature may,
however, be as potent a factor in excluding E. hamata from the Gulf Stream as high
salinity.

C.I.V.4/>/.^.Y FfSlfKh'IKS F.XrKniTloy, 191 ',-15

479

The absence of this species generally in the hauls from 130 metres to the surface
in the gulf on the August cruise of the Princess and its occurrence in such a haul at
Princess station '.'A indicates an upwelling of the deep boreal oceanic water at that
point.

The definite separation of this species from S. elegant in vertical distribution as
seen at No. 33, station 23, shows that they belong to waters of different salinities.
Where they occur together in mixed water, as south of Sable island or in the Bay of
Fundy, E. hamata is to be found only in small numbers, showing that this mixed
water is not suitable for it.

To the south of our area, Bigelow, (1915, p. 297) has found this species in the
deeper parts of the gulf of Maine and along the edge of the continental shelf as far
south as Chesapeake bay in July-August, 1913. Its outer limit was, however, nnt
determined. It decreased in quantity to the south,

Apstein (1911, p. 174) for European waters gives its distribution as similar to
that of S. maxima, but occurring regularly in the iSTorwegian channel; and in the
Skager-Rack, where it was abundant, it occurred at the surface, but was most abun-
dant in the depths. This is quite similar to the conditions on our coast, where it
passes landward up the deep gullies, and much farther than does S. maxima.

(./') Krohnitta subtilis (Grassi).

1911. ]iitt(>r-Zahony. p. .32.

"Acadia".

Station No.

Depth

(metres).

Depth of Haul (metres).

Length (mm.).

Xumhor.

44

over 1 , 000

270-

0 (V.)

13-5

1

0 (T.)

0

A single specimen of this species was obtained at station 4-t, the southernmost
station of the second cruise of the Acadia, in an open-net vertical haul from 270
metres (fig. 1, vertical dotted lines). It is a tropical species occurring chiefly in th(?
raesoplankton; according to Eitter-Zahony, chiefly in the lower epiplankton and upper
mesoplankton ; according to Fowler (1906, p. 74), and according to Michael (1913, p.
35), chiefly between 200 and 250 fathoms (none above 50 fathoms). Fowler gives its
most northerly record in the Atlantic as 60° 12' X., 22^ 56' W.

(GENERAL SUMMARY OF DISTHIBFTIOX,

In sununarizing the distribution of the Chaetognaths it will bo well to review
briefly the principal features of the region covered.

The general topography as shown in the charts is too well known to require
description. The submarine physiography has been described by J. W. Spencer {see
chapter ix of Sub-Oceanic Physiography of the North Atlantic Ocean, by E. Hull,
London, 1912; and Bull. Geol. Soc. Amer., vol. xiv, 1903, p. 207). The main feature
is the submerged Laurentian valley cutting across the middle of the St. Lawrence gulf
and passing out to the open ocean through Cabot strait aiad between St. Pierre bank
and Banquereau. We have referred to this as the Laurentian channel. Another

480 DEPARTMENT OF THE NATAL SERVICE

channel, the Cansan, cuts through between Sable Island bank and Banquereau.
Farther to the south is the Fundian channel passing out from the Bciy of Fundy and
through the gulf of Maine. These three channels delimit two portions of the con-
tinental shelf off Nova Scotia. That to the north between the Laurentian and Cansan
channels includes the Banquereau, Misaine, and Cansan banks, and may be called the
Breton portion of the shelf, or the Breton bank, since it lies off Cape Breton island.
The southern part lies between the Cansan and Fundian channels and includes La
Have and Sable Island banks. It may be called the Scotian bank since it lies against
the main portion of the province of Nova Scotia.

In the St. Lawrence gulf we have to the north of Anticosti island, the Anticostian
channel, and running north towards the straits of Belle Isle the Esquimau channel.
To the south of the Laurentian channel in the gulf is an extensive submarine plateau
with, for the most part, less than 30 fathoms of water covering it. Cropping up from
it are the Magdalen islands and Prince Edward island. This area is peculiar in its
biological and hydrographical characters. We have referred to it as the Lower Gulf
region. It might be called the Magdalen bay.

The currents of the region have been thoroughly investigated by Dr. W. Bell
Dawson, and his results published in the reports of the Tidal and Current Survey of
Canada from 1894 to 1913, including special reports on the currents. In the gulf of
St. Lawrence he finds that the general circulation is in a left-handed direction and
chiefly confined to the deep central portions. A current enters the gulf through Cabot
strait off cape Ray and spreads out to the north and northeast. Part runs up the
Esquimau channel on the east side and returns on the west. Similarly a current runs
up the Anticostian channel on the north side and returns on the south, and up tlje
Laurentian channel between Anticosti island and the Gaspe coast on the north side
and returns on the south. The last of these, the Gaspe current, is very strong and
spreads to the southeast over the Magdalen bay, passing to either side of the Magdalen
islands, and finally as a single stream of constant strong character, the Cape Breton
current, it emerges from the gulf on the south side of Cabot strait.

Dr. Dawson has shoiwn by density determinations that the inflowing water is more
saline than the outflowing and, as a result, the northern part of the gulf is constantly
more saline than the southern, a line of division passing from East cape, Anticosti
island, to the middle of Cabot strait.

The shallower channels of the gulf show the same circulation but to only a slight
degree. Through the straits of Belle Isle and the Mingan channel on the north there
is a general inward or westward tendency, and through the Northumberland strait
(and perhaps also the Gut of Canso^ on the south a general outward or eastward
tendency.

Outside the gulf there is a slight westward tendency on the southern coast of
Newfoundland and a southwestward drift along the outer coast of Nova Scotia. In the
gulf of Maine, Bigelow has found a general left-handed circulation, entering the gulf
on the north and leaving it on the south. In the Bay of Fundy there is doubtless a
similar circulation, although so masked by the heavy tides that Dawson has been
unable to determine it by current measurements.

Farther out we have two well-known strong currents, the Polar or Labrador
current coming down from the north along the outer coast of Newfoundland, flooding
the Grand Banks and then turning to the east at their southern border; and the Gulf
Stream coming from the southwest along the coast of the United States and being
deflected to the east and south just south of the Grand Banks.

As a basis for our knowledge of the different kinds of water occurring in the
region we may take the three sharply marked zones found ly TTjuvt off our eon t^ in
1910 (Murray and Hjort, 1912, p. 109) in his section from the Azores to Newfoundland.
There are the following: (1) a Northern Coastal zone (Arctic?) on the Newfoundland

1 1 have just received from Dr. Dawson a proof sheet of a forthcoming report in which he
describes a preponderance of outflow to the south througli the Gut of Canso.

CAXADIAX FlSlli:iiIi:S EXPEDiriOy, lOl.'rlo 481

banks, with water of low salinity (under o3"/oo) and very low temperature (down to
1-5° C.) except at the surface in summer; (2) a Northern Oceanic zone (boreal) along
the southern side of the Grand Banks, with water of moderately high salinity (33-
35Voo) and moderately low temperature (3°-8° C), which connects with the bott(jm
water of the Atlantic; and (3) a Southern Oceanic zone (tropical) farther to the south
in the Gulf Stream, with water of high salinity (over SS^oo) and high temperature
(10°-25° C).

The nortliern coastal water owes its low salinity to the fresh water poured in by
the rivers and to tlie melting of the icebergs from the north, and its low temix-rature
to the cooling effect of the rigorous winters and to floating ice.

The southern oceanic water is brought up from the tropics by the Gulf Stream.
This accounts for its high temperature and salinity.

The northern oceanic water may be derived in part from a mixture of the two pre-
ceding kinds. It is essentially an intermediate water, and in its circulation will, on
the one hand, have its temperature and salinity reduced by mixture with the coast
water and, on the other hand, have its temperature and salinity increased by mixture
with the Gulf Stream water. As it is heavier than they, it will be found beneath them
and, particularly toward the south, where it is less extensive, it will permit of their
mixing together above it. It is continuous around the south side of the Grand Banks
with the open water of the northwestern Atlantic, where is found the Labrador current.
The latter doubtless contributes along this course (around the banks) to our northern
oceanic water, but for the most part only at some depth and not on the surface.

To these may be added a fourth, the Southern Coastal zone existing in the 'Mag-
dalen bay, to which certain southern coastal forms, e.g., the oyster, are restricted. It
is characterized by water of very low salinity and very high summer temeprature. and
is therefore similar to the upper layers of the northern coastal water. Its low salinity
is due to the large amount of fresh water poured into it by the St. Lawrence and other
rivers. Its high summer temperature is due to the same cause and to the shallowness
of this part of the gulf. In a negative way the absence of heavy tides contributes
to both the low salinity and the high temperature.

In the Southern Oceanic zone we have at the surface Sagitta eJiflata, S. hipundata,
small 8. serratodentata, and Pterosagitta draco. In the depths there are iS^. hexaptera,
S. lyra, and KhronUta suhtilis. The extent of this zone in July-August is shown in '
fig. 1. Surface species are indicated by horizontal lines, deep-water species by vertical
lines. The further extension landwards of the surface forms in the southwest part
of the region and of the deep-water forms in the northern part is noteworthy. This
is corroborated by the distribution of small S. serratodentata as shown in fig. G. The
nearness of the zone to the continental shelf on the south as compared with the north
is also important, indicating a turning of the Gulf Stream to the east.

On the May-June cruise only the northern part of the area was investigated.
Only deep-water species were obtained. The records show that the surface Gulf
Stream forms, which were not found, must have been farther out than the deep-water
forms, and that both were at that time farther from the continental shelf than in July-
August.

There is the question as to what part the Gulf Stream plays in mixing with either
the coastal or the boreal oceanic waters. The sharp inner mar^ns of the areas of
distribution of most of the Gulf Stream species is against the view that the Gulf
Stream by any back eddies remains as a distinguishable part of our waters. In the
upper layers the most abundant species (S. enflata) decreases in abundance toward the
inner side of the stream, and may even be lacking, showing that this inner margin is
mixed water going with the stream. A solitary individual was found inside the
stream, far in on the Scotian bank off Halifax. Its ability to survive in the water of
interrnediate salinity and temperature indicates that there can be little water of Gulf
Stream origin in the intermediate boreal oceanic zone, otherwise individuals of this
species would have been obtained at some of the nine intervening stations. S. serra-

482 DEPARTMEXr OF THE XATAL SERVICE

todentata is a Gulf Stream form, but its occurrence in the boreal water is not indi-
cative of a recent Gulf Stream origin, since it is of a decidedly different type in the
boreal water. Its abundance in our boreal water and its rarity on the European coast
may be due to its ability to live and grow to maturity but not to reproduce success-
fully in boreal water. With this interpretation our boreal water would have a very
slight but constant contribution from the Gulf Stream.

Of tlie deep-liviijg species, 8. hexaptera is absent from the boreal wa<ter, but
*S'. lyra was found at two of the boreal stations. One of these stations was, however,
really on the edge of the Gulf Stream, and the single specimen found at the other
station (Acadia station 70) was much larger than any others obtained. This indi-
vidual may have passed through the bottom of the Gulf Stream, since the species goes
into very deep water and is a constant inhabitant of the depths of the Atlantic ; or if
it has entered the boreal water by the mixture of the latter with the Gulf Stream, its
size precludes a recent entrance.

We have therefore no certain evidence of any deep contribution of Gulf Stream
water to the boreal zone in our region, and evidence of only a slight surface contri-
bution.

Of movement in the opposite direction, from the boreal water to the Gulf Stream,
since there is no peculiar surface boreal form, we have merely the negative evidence
of rarity of the surface tropical species at the northern Gulf Stream stations. The
deep-living boreal species, <S'. maxima, was regularly found at the Gulf Stream stations
except at the extreme southwest, and it was more abundant at the north, while
Eukroknia liamata was found at only one of the stations, the most northerly {Acadia
station 74). There is therefore evidence that the boreal water does contribute to the
Gulf Stream in the deeper part, and perhaps also at the surface. The latter contri-
bution will tend to be indistinguishable from coastal water.

In the Northern Oceanic zone we have large ,S^. serratodeniata at the surface, and
in the depth, 8. maxima and E. hamata. For its extent in July- August see figs. 3,
6 (vertical lines), and 12. There is to be seen an extension of the surface water over
the Scotian bank to the south, and of the deep water up the Laurentian channel to the
7iorth. The deep water is present in small amount over the Scotian bank, the surface
.vater in the Laurentian channel, and both in the gulf of Maine and Bay of Fundy.
The virtual absence of this water over the Newfoundland banks is worthy of note, it
being held off by the coastal water. Its centre is seen to be a narrow zone close against
the continental shelf, decreasing in width to the southwest. The vertical distribution
of 8. maxima and E. liamata shows that it passes to a deeper level below the coastal
water up the Laurentian channel and below the Gulf Stream to the south and south-
west.

On the May-June cruise the small area explored showed a similar distribution,
but extending farther out from the continental shelf.

The absence of any continuation of the deeper part of this water (as indicated by
E. liamata and 8. maxima) along the continental shelf oft" Shelburne in July- August
as shown by our most southern section, indicates the abruptness of the transition from
Gulf Stream to coastal water at this point, the boreal water having been squeezed out
by the pressing in of the Gulf Stream close to the continent. This is doubtless
temporary. At another time, perhaps earlier in the season, the boreal water would
be much more extensive and pass continuously down the coast and up into the gulf of
]\raine.

Dawson has shown that in the deep parts of the St. Lawrence gulf there is water
with the characters which we have given above for boreal oceanic. The Albatross, as
reported by Townshend, found in July, 1885, very low temperatures at the bottom
which would indicate no boreal water on the bottom on the banks just south of New-
foundland, on the Breton bank, nor close along the shore of Nova Scotia; but in the
mouth of the Laurentian channel and off Shelburne near La Llave bank the bottom

CANADIAN FISHERIES EXPEDITION, 1914-15 483

temperatures were higher (37-8° — 40° Fj, indicating boreal water. For the banks just
south of Newfoundland, Dawson's investigations did not go deep enough, but iljurt
failed to find it at the bottom, or only in very small amount at the north. The Chal-
lenger, on May 20, 1873, found, just east of La Have bank, water at the bottom with
too low salinity and temperature to be boreal. For the early part of the year the boreal
water may be absent from the Scotian bank. Bigelow has found boreal water at the
mouth of the Bay of Fundy. With the exception of the ChalleiKjer record, for which
the season of the year may be responsible, the distribution of the Chaetoguatlis agrees
with what has been found as to the extent of the boreal oceanic water.

As to its origin and movements, we have seen that there is little reason to suppose
that the Gulf Stream contributes appreciably to it. It must therefore come either
from the deeper part of the Polar current around the outer side of the Grand Banks
(its comparative purity at the north as shown by the quantitative distribution of
S. maxima and E. hamata support this view) or by upwelling from the depths of the
Atlantic, since it is being constantly dissipated by mixture with the coastal water.
That it is actually moving toward the southwest seems to be shown by the movement
of the centre of abundance of S. serratodentata to the southwest during the summer,
and also by the rarity of the boreal species over the Scotian bank, which is an indica-
tion that boreal water is passing in that direction and being dissipated.

The greater abundance of the boreal species on the northern side of the Laurentian
channel is an evidence that the boreal water forms part of the current entering the
gulf. On its way it must be mixing with the coastal water, as is witnessed by the
presence of E. hamata near the surface. This doubtless explains the failure of two
of the species to enter the gulf. The third species certainly passes up the Laurentian
ichannel as far as the Gaspe coast, although it is unlikely that it reproduces there.

The boreal oceanic water may be considered as coming from the northeast, and
in our region disappearing partly by mixing with the coastal water, particularly in
the Laurentian channel, on the Scotian bank and in the gulf of Maine, partly by
mixing with the Gulf Stream and returning to the northeast and partly by sinking
beneath the Gulf Stream to pass into the Atlantic bottom water.

In the Northei'n Coastal zone there is only a single species, S. elegans. Young
individuals characterize the upper layers, large individuals the lower layers, and very
large ones the deepest parts. Fig. 9 shows the distribution in July-August, horizontal
lines representing individuals under 20mm., and vertical lines those over 20mm. The
general extent of the zone corresponds with the continental shelf, but passes beyond
it to some extent in the north, particularly at the mouth of the Laurentian channel.
The only parts of the shelf not in the zone are the Xorthumberland strait and the
extreme outer part of the Scotian bank. The former is occupied by the southern
coastal water, and the latter by the boreal oceanic water. If we exclude the smaller
individuals, considering that they belong properly to the southern coastal water, the
zone is more restricted, the shallower banks and particularly the Magdalen bay being
excluded. This intermediate water containing chiefly the large individuals over
20mm. in length has a salinity of from 3lVoo to 33Voo and temperature ranging from
about 10° C. down to — 1-5° C. Its apparent absence in the northern part of the gulf
will be explained later. Its full development as indicated by the largest individual? of
S: elegans occurs in deep fjords like the Bay of Islands, and to a less extent over the
Breton bank. The May-June cruises show less difference between the upper and lower
layers, large S. elegans being nearer the surface, and therefore in shallower water and
more generally distributed. The zone as a whole was at that time more extensive,
covering parctically the whole area investigated, extending into Xorthumberland strait
and out to the outermost station in the Atlantic. The species was, however, not
abundant near these limits nor over the shallower banks.

The effect of the currents on the coastal water and this coastal species would seem
to be the following: The circular motios around the gulf acts as a huge whirlpool and
tends to collect S. elegans in the central portions. "Wherever data are available they

6551—35

484 DEPARTMENT OF THE A^AYAL SERVICE

show that more individuals were in the middle in the various channels, where Dawson
has shown that the water is comparatively stationary, than along the sides. Four of
the channel sections show this.

The outflowing Cape Breton current depopulates the gulf to a considerable extent,
the older individuals being much less numerous during the second cruise. They are
carried by the current along the southern side of the Laurentian channel out into the
open Atlantic oil' the continental shelf for some distance and also into the deeper water
on the Breton bank. Such a course for the coastal water is indicated imperfectly by
Dickson's charts for surface temjjerature and salinity for the North Atlantic for the
years 1806 and 1897 (Phil. Trans., A, vol. 196, pis. 1-4, 1901), in which can be seen a
tongue of water of low salinity, warn in summer and autumn and cold in winter and
spring, extending along this course from Cabot strait. This is evidently a very per-
manent condition. The continuation of this tongue toward the southwest along the
outer side of the continental shelf, as appears, in fig-. 8 at Acadia station 12, may well
be a regular course for a part of the coastal water in the colder part of the year. It
will connect south of Sable island over the Scotian bank with the band of coastal water
along the JSTova Scotia shore. This view is supported by the finding of coastal water
at the bottom near La Have bank by the CJxallenger in May, 1873, and by the presence
of !S. elegans at Acadia station 54 (see fig. 10) which would be a last remmant for the
summer of this current. This cui-rent and the more constant one close to the Nova
Scotia coast carry the species to the southern end of Nova Scotia and heap it up there
as is seen in fig. 10. During the two months between cruises the currents have trans-
ferred the centre of abundance from the Laurentian channel to the lower end of Nova
Scotia, only a part being left on the Breton bank.

The current along the southern coast of Newfoundland may carry coastal water
and with it this species to Cabot strait and possibly into the gulf. That it does not
enter to any great extent into the current running in past cape Ray will appear from
the following considerations. The stations in the northern half of the gulf during
both cruises showed few or no large 8. elegans. The cold intermediate water in which
it lives is present in this part of the gulf but will have been formed by the mixture of
the inflowing boreal water with the surface water, neither of which contain large
8. elegans. Consequently, few or no large individuals are to be expected in the first
part of the water's course, that is in the northern half of the gulf. If it were derived
from the coastal water south of Newfoundland, this would not be the case.

The loss of large individuals from the gulf through Cabot strait being greater than
the gain, the gulf would be depopulated were it not for the yearly swarms of young
individuals growing up in the surface layers. These will likewise be carried out, but
since they are several times as numerous as the adults, enough will be left to keep up
the stock. The more or less stagnant areas in the gulf, for example the Bay of Islands
fjord, will aid in repopulating the whole area. The conditions in that fjord are most
suitable for this species. The bar at the mouth prevents the egress of the large
individuals during the summer at least and yet permits of many of the young escaping.
We found only the latter at the mouth in August. In the deepest haul in the bay,
where there was over 2O0 metres of suitable water, seventy large individuals were
obtained. This may be considered the upper limit for the number that is normal to
an area. More than this would certainly be due to concentration, as for example the
areas of abundance shown in figs. 8 and 10. The numerical relation between the
adults and young is interesting. At both stations in the Bay of Islands where vertical
hauls were made {No S3 stations 57 and 59) the young were about fifteen times as
numerous as the adults (^-%2 and ^''^%o). This provides a very considerable surplus
to overflow into the neighbouring depopulated part of the gulf.

The areas of distribution of the boreal oceanic and northern coastal waters overlap
to a great extent. In the gulf of St. Lawrence where conditions are moderately static
they are separated vertically, the boreal water being below. Elsewhere the separation
is not so complete, more or less active vertical mixing going on, as is evidenced by the

CANADIAN FISHERIES EXPEDITION, 19U-15 485

two groups of species being mixed and the deep forms found near the surface. The
chief large areas of this kind are along the Laurentian channel from Cabot strait out
to some distance beyond the edge of the continental shelf, the central portion of the
Scotian bank, and the -Bay of Fundy.

The typical northern coastal water, as we have described it, has been found by
Dawson generally in the gulf of St. Lawrence, along the outer coast of Nova Scotia
and around the southeastern corner of Newfoundland. The Albatross records show
that it was present in July, 1885, on the banks off cape Race, on the Breton bank and
along the Nova Scotia shore. Bigelow's results show it in the mouth of the Bay of
Fundy, and Copeland's account demonstrates its presence at the bottom in Passama-
quoddy bay, as at Prince station 4. This is in entire accord with the distribution of
S. elegans.

In the Southern Coastal zone there are no Chaetognaths or merely small S. elegans.
It is scarcely distinct from the northern coastal and might be taken to include the
surface layers of the latter. This would give it a salinity of less than 3lVi»o and a
summer temperature of from 10° to 20° C, although a somewhat higher salinitj^ would
not be excluded. It occurs typically in the Magdalen bay, particularly toward the
south. Elsewhere it is not so typical and grades into the northern coastal water. The
surface waters generally over the continental shelf approximate to the southern coastal
type, except in the Bay of Fundy where the heavy tides increase the surface salinity
and lower the temperature. As a result of this there is a virtual absence of small
S. elegans in the Bay of Fundy.

The movements of this water are not indicated by the Chaetognaths, but it will
be carried out of the gulf by the Cape Breton current, and perhaps also to a slight
extent through the Gut of Canso. It arises by a mixture of the river water with the
northern coastal, and is dissipated by mixture with the latter and with the boreal
oceanic.

CANADIAN FISHERIES EXPEDITION,
1914-15.

QUANTITATIVE INVESTIGATIONS AS TO PHYTOPLANKTON

AND PELAGIC PROTOZOA IN THE GULF OF ST.

LAWRENCE AND OUTSIDE THE SAME.

PY

H. H. GRAN.

Royal Frkfjeuick Uxiversity, Ciiristianu, Norway.

4ST
G551— 3G

QUANTITATIVE INVESTIGATIONS AS TO PHVTOPLANKTON AND PELAGIC
PROTOZOA IN THE GULF OF ST. LAWRENCE AND OUTSIDE THE SAME.

By II. H. Gran.

The plankton investigations wliicli have been carried out in North European waters
since P. T. Cleve and Aurivillius, in the nineties of the past century, made their pioneer
researches on the phuikton of the Skagerak, and which from 1901 have been under
the guidance of the International Council for the Exploration of the Sea, have, as a
first general result, given us a very close knowledge of the distribution of the different
:,pecies and their relative frequency at the various seasons of the year. A survey of
die data thus acquired has been issued by the Council in a series of papers, edited by
Dr. C. II. Ostenfeld.i

The next aim of the investigations is to enable us to determine the quantitative
occurrence of the plankton as a measure of the production in the different areas of sea.
The question was already raised by Hensen, and his methods of operation, by vertical
hauls made with " quantitative " nets and countings of individuals in certain fractions
of the catch — or simple determinations of volume for the whole — made the first steps
towards a solution of this great and many-sided problem. With the fundamental work
of Lohmann in this field, a great advance was made in regard to the methods employed,
and we are now able to determine the quantity of plankton in relatively small water
samples, by means of the centrifuge. In seeking to ascertain the relation of plankton
production to various external conditions, such as light, temperature, salinity and food,
it will not be enough to work merely with samples taken in vertical hauls, as the con-
ditions in question are by no means uniform throughout the entire column of water
filtered by the net. A series of water samples, on the other hand, taken at the same
locality, but at different depths, will show how the quantity of the plankton varies with
the depth, so that we can, with a suiRcient quantity of material, ascertain the depend-
ence of the production upon the different factors, which vary in a horizontal as well
as in a vertical direction, throughout the sea.

A further improvement of the method, and adaptation of the same to particular
purposes, was made when I succeeded in finding a means of preserving water samples
by means of Flemming's liquid, added in the proportion of 1-25 ; this rendered it pos-
sible to collect a greater quantity of material in a short time, and store it for subse-
quent thorough investigation. The method was employed for research work through-
out the whole of the year in the Norwegian coastal waters, as also in extensive investi-
gations of the North sea and North Atlantic, carried out in ^lay-June, 1912, by the
North Sea countries acting in concert.-

The large amount of material and observations collected in the course of these
investigations presents various points of difficulty in regard to judging the results,
as it is distinctly seen that the conditions in the sea are rarely, if ever, so stationary
that we can immediately presume the existence of causal relation between the quan-
tities of plankton found at any spc>t and the conditions of life there prevailing at the
time. The plankton moves, not only with the currents in a horizontal and a vertical
direction, but sinks to a great extent, and rises also, though in a lesser degree,
actively, within the water mass in which it has developed. We often find, for instance,
considerable quantities of pelagic algte at depths far beyond the level at which they
can have developed; so far down, indeed, that their assimilation of carbonic acid

1 Bull. Trimestriel .... Resume des Observations sur le Plankton, Parts 1-3, 1910-19«13.

3 H. H. Gran. The Plankton Production of the North European Waters in the spring of
1912. Bulletin Planktonique pour I'annee 1912, publie par le bureau du Conseil Permanent Inter-
national pour I'exploration de la mer. Copenhague 1915.

489

490 DEPARTMENT OF THE NAVAL SERVICE

must be far less than their respiration; there can hardly be any possibility of con-
tinued propagation here. Thus even the comparatively simple question as to the limit
of depth at which assimilation predominates over the destructive metabolism of chloro-
phylliferous organisms offers in itself considerable difficulty, and can hardly be solved
by mere investigation of the vertical distribution of the organisms concerned.

The investigations in question did, however, furnish various important results
which could serve as basis for further research; among these, the following may be
particularly mentioned: —

(1) The diatoms, which appear to be the most rapidly growing of all producers
in the sea, develop in great quantities in the coastal waters of Northern Europe during '
the later winter months (February-April) while the temperature of the surface layers
is still at or slightly above the minimum for the year. They are restricted to a cold
surface layer with comparatively low salinity, lying above water layers of considerably
higher temperature. The .greatest quantities are found in places where there is a
continual inflow of water either from the land, e.g. from the Baltic, and from the
rivers of Northern Europe, or fi-om the ice limit of the Arctic ocean, but where the
fresh water has nevertheless become so mixed with salt that there is a certain degree
of stability in regard to osmotic pressure. The supply of foodstuffs brought down by
the river water seems to play an essential part in this production.

(2) The great production of diatoms in the coastal waters ceases in May-June,
when the surface layers become warmer. At this time of year, there may be a second-
ary minimum in the total quantity of phytoplankton, until the mobile algae, chiefly
Ceratium, propagating in the warmest season of the year, have reached such numbers
as to replace the diatoms. Local and temporary maxima of diatoms may, however,
occur also in summer, especially in the vicinity of the coast after a rainy spell, when a
rich supply of foodstuff in solution has been carried down from the land. In summer,
then, the conditions of life must be unfavourable to diatoms, the marked isolation
between the warm, light surface layer and the waters below preventing any introduction
of nutritive matter by vertical circulation or mechanical mixture, and also because
they are ill able to keep floating in the water layers of low specific gravity, which are
also, owing to their high temperature, of comparatively slight viscosity. These obstacles
can be surmounted by the mobile Ceratium, though these also exhibit a distinct
tendency to sink down towards the limit of the surface layer — but not by the diatoms,
save where circumstances are particularly favourable with regard to nourishment, as
by abundant supply of food from the land. In the autumn, when cooling begins, when
the autumn gales and also the purely mechanical equilibrium of the water layers
drives the surface water towards land, so that both vertical circulation and a stronger
mechanical mixture can take place, then the conditions are more favourable. At this
season, in October-November, we find a new maximum, and the diatoms can then,
at any rate, in some years, again occur in quantity.

The characteristic feature, then, of North European waters, considered as feeding
grounds for pelagic plant life, is the rich supply of river water, which in a mixed
state flows over the surface in thick layers in the vicinity of the coasts. This supply
is probably the most important source of the great productivity of the entire area of
sea, but it is just in the hottest season, when the surface layer is most markedly
isolated from the remaining water masses, that it offers the least favourable conditions
lor production.

The waters about the east coast of Canada present numerous points of resemb-
lance in oceanographical resi)ects to what we flnd off Northwiestern Europe, and it may
therefore be interesting to try how far the working hypotheses above set forth may be
applicable to conditions on the coast of America. I was therefore happy to avail
myself of Pr. Hjort's kind offer to collect a series of water samples in and outside

C'AXADIAX FISUKRIES I.X I'KDn li)\, I'Jt'rlo 491

the gulf of St. Lawrence, according- to the same method as we have followed in Europe.
The method is, it must be admitted, not without certain limitations, and these become
more than usually apparent when dealing with a water whose phytoplankton is less
known, or where, at any rate, the annual periodicity of the species, a point with which
we are here especially concerned, is very little known indeed. The comparatively small
samples offer no occasion for critical consideration of the species from a systematic
point of view, or for description of the rarer forms. All species of common occurrence
are, however, well known from the North-European waters, so that this is only of
minor importance. A more serious difficulty is the fact that an investigation such
as the present can naturally give widely different results at different seasons of the
year, and it will consequently be impossible to determine at what season the samples
should preferably be collected, when seeking to obtain, from a limited quantity of
material, a view of the characteristic features in the production of the water con-
cerned.

The present material was collected at two different seasons, in early summer
(May 29 to June 15) and, later on, in August. The former period would, on first
consideration, appear very favourable, provided that the conditions prevailing were
anything like those of Northern Europe; we should at this time expect to encounter
the transition between the rich spring plankton and the incipient development of the
summer plankton ; in August, on the other hand, the summer plankton should be near-
ing its culmination, though this would probably not be actually reached until Sep-
tember.

The results show us a plankton essentially consisting of the same species as are
also found on the other side of the Atlantic, but which is both qualitatively and
quantitatively poorer than that of the European waters. We must doubtless reckon
with the possibility that the greatest maxima are found at other seasons of the year
than those covered by the present investigations; this is, indeed, more than likely
to be the case. In the North-European waters, the diatoms have their maximum
in March- April, when the surface temperature is at the annual minimum; this
mass development of diatoms is here composed chiefly of northern, and to some
extent of Arctic species with low temperature optimum, and the Arctic character
becomes more and more pronounced farther to the north. Such a maximum was
encountered in the gulf of St. Lawrence on the 11th of May, when no plankton samples
were taken for quantitative investigation, but only qualitative samples, taken in the
ordinary nets. These samples were very rich, and consisted of markedly Arctic
species, a community such as we find in May-June off the coasts of Greenland or in
the Barents sea, or, to a less pronounced degree, off the northwest coast of Norway in
April. It also exhibits great resemblances to the plankton described by P. T. Cleve
from the water about Disco island in May, 1894.1

1 P. T. Cleve, Diatoms from Baffins Bay and Davis Strait, collected by M. E. Nilsson, 1896,
Bihang till K. Svenska Vet. Akad. Handlinger Bd. 22 Afd. Ill, No. 4.

492 DEPARTMENT OF THE NATAL SERVICE

The following species were found: —

Achnanthes twniata Grun., abundant, with resting spores
AmpJnprora hyperborea (Grun.) op^i co.

Bacterosira fragilis Gran.
Bidclulphia mirita. (Lyngb. )
Chwtoceras atlanticum. Cleve.

compressum. Lander.
criophilum. Castr.
debile. Cleve.
decipiens. Cleve.
diadema. (Ehrbg.) Gran.
scolopendra. Cleve.
teres. Cleve.
Detonula confervacea. Cleve.
Eucampia groenlandica. Cleve.
Fragilaria cylindrus. Grun.

oceanica. Cleve, predominating, with resting spores
Navicula pelagica. Cleve. fpoies.

septenirionalis. Oestrup, abundan
Vaiihaeffeni. Gran.
Nitzschia closterium. W. Smith.

frigidki. Grun.
Pleurosigma Stuxbergi. Cleve et Gran.
IZhisosolenia hebetata (Bail.) f. semispina, Hensen
Thalassiosira bioculata. (Grun.)

gravida. Cleve, with resting spores.
hyalina. (Grun.)

Nordenskioldi. Cleve, predominating.
J halas.siothrix longissima. Cleve et Grun.
Dinophysis granulata. Cleve.

No such quantitie.s of diatoms were found in any of the quantitative samples from
June to August, and the species of diatoms which characterize the rich spring plank-
on ^re only found at some few stations in the gulf of St. Lawrence (stations 10 and
Vol V } \ '^ ^""^ ^''^^ *^^'^ ^" ^^^^^'^ quantities, and restricted to the

ha"t theTh " ^r'y\''' '' ^' ^- ^^P'^- ^^^°"^ ^^"^ -^ -^y presumably conclude
of Tut f^l^'''''^l''^'^'^' -^P""^ plankton has already disappeared by the middle
of June or has sunk down to deeper water layers, whore remains of it are found for
the most part with resting spores. ^uunu, lor

Cruise of the "Princess '^ June 9 to 15 (Table 1 (a), (b), and (c).

The plankton samples from the cruise of the Princess, June 9 to 15, 1915 dis-
tinctly show that the development of the pelagic diatoms at this season has passed it^
annual maximum. In the first place the markedly Arctic species, mentioned above,
have sunk down to the deeper water layers, where we may certainly presume that they
will no longer find conditions suitable for their further development, and have to a
considerable extent formed resting spores. But in addition to this, we find thaJ a

and CJ. lacznwsum which somewhat later must have replaced the Arctic species is
now a ready declining. These species we find more particularly at the stat on

rran -tv -n ib^^'^'^"" l' '' 'V ^^' ''^- ^^^^^ '^'^^ are Hkewise not found

necre? T J r ^""^"'f ^^V^'^ ^"^" '''' ^^^"^ ^« deep dowia as the Arctic

species. I heir maxima lie, as the table shows.—

At station 3, at 20 m.
5, at 10 m.
" 10, at 0-25 m.

12, at surface, but small quantities.
25, at 30 m., but sparsely.

The stations where they are found nearest the surface (stations 10, 12) have lower
surface temperature than the places where the diatoms had almost or entirely dis-

menced in these species also.

CANADJAX I'lSUERIES EXI'EI>[T1()\ . lUI',!-', 493

The species which in June predominate in the surface layers are, on the one hand,
the brown Cilioflagellates Dinophysis norvegica and D. acuminata (Especially at
stations 5, 6, and 8) ; and, on the other hand, infusoria. Foremost among these we
find the remarkable Mesodinixim ruhrum, and species of the genus Lahoea, the distri-
bution of which is, up to the present, but little known, as all previously known methods
of collection and preservation render them unrecognizable. Of the Lahoea species,
two in particular are found to predominate, viz., L. conica Lohmann, and L. vestita
Leegaard. Both the Mesodinium and these two Lahoea species are distinguished by
the presence of chlorophyll (covered by a brown colouring matter) and thus belong to
the producers of the plankton. Mesodinium is, according to Lohmann's investiga-
tions, doubtless colourless in itself, but lives symbiotically with small brown algae,
which fill the whole of its cell. The two Lahoea species — in contrast to several others
of the same genus — are brown, which fact I have been able to convince myself of by
investigation of living material; up to the present, however, I have not been able to
ascertain exactly whether the colour is due to captured algal cells or belongs to organs
in the cells of the infusoria themselves. In any case, these three species appear to have
been the most important C'02-assimilating organisms in the gulf of St. Lawrence in
June, 1916. Lahoea conica has hardly been found before at any place in such great
quantities as here (over 3,000 per liter at stations 6 and 8, over 5,000 at station 16).

It may appear remarkable that just these interesting organisms which unite the
nutritive power of the plants with the lively movement of the animals, should be the
first to populate the surface layers after the conclusion of the diatoms' period of
development, but as their development otherwise is at present little known, we cannot
deeidte whether the feature in question is characteristic of the gulf of St. Lawrence.

A further noteworthy point is the comparatively large quantities of colourless
Gymnodinium species, especially G. Lohmanni. This Cilioflagellate subsists by absorb-
ing solid bodies into its interior; whether it is also capable of absorbing dissolved
organic matter from its surroundings has not yet been determined. An occurrance of
3,000 per liter (station 8) or 5 per ec. is a very considerable quantity for so large an
organism, obliged to live upon organic food, and may be taken as a certain sign that
it finds particularly favourable conditions for development.

Cruisk of the "Acadia'' May 29 to 31, 1915 (Table 2).

The samples from the Princess are supplemented in an interesting manner by the
series taken somewhat more than a week earlier by the Acadia in the sea outside the
Gulf of St. Lawrence. Most of the stations have, however, a plankton surprisingly
poor in quantitative respects; this applies especially to stations 2, 4, 10, and 12. The
quantities found are in reality so small that we must presume that the conditions for
development cannot have been favourable to the phytoplankton. Of producers, only
quite small quantities were found of colourless Cilioflagellates (Gymnodinium Loh-
manni), with infusoria (Lahoea sipecies) somewhat more numerous. The method of
preservation leaves it an open question whether Coccolithophoridae, whose calcareous
shells would have been dissolved by the acid employed, or small flagellates, which are
difficult to find in a preserved state, were or were not present. If no such sources of
nutrition occur it will be difiicult to explain the finding of so rich a stock of organisms
unable to assimilate carbonic acid for themselves. At station 10, however, we find at
the surface a quite rich stock of the assimilating Lahoea conica.

An exception is formed by the two stations 6 and S, which have a rich diatom
plankton, with Leptocylindrus danicus, and at station 8 also Chcetoceras' dehile. This
plankton resembles both in quantity and quality that Avhich may be found on the
coasts of Northern Europe in May. Both the composition in regard to species, and
the abundance, point to a distinct coastal influence; the species are neritic, and the
rich development is most probably due to dissolved nutritive matter from the coastal

494 DEPARTMENT OF THE NATAL SERVICE

sea. The vertical distribution is peculiar; at station 6 we find Lepiocylindrus danicus
almost evenly distributed from surface to bottom, though with a certain increase in
numbers toward the lower levels. We may be justified in concluding that this even
distribution is a result of vertical movements, either of the water masses or of the
diatoms themselves, which, after a rich development at the surface, have then sunk
down to deeper layers. At station 8, this development is somewhat further advanced;
the rich diatom plankton has almost disappeared from the warmer and somewhat less
saline surface layer, and is first met with at 30 m. and thence down to the bottom.

Leptocylmdrus danicus represents, on the coasts of Northern Europe, the last
phase in the development of the spring diatom plankton, and the same appears to be
the case in the waters here investigated, where the development already seems to be
nearing its conclusion in the last week of May. Here, however, we do not find, as we
do in Europe, any rich plankton of Cilioflagellates ready to replace the diatoms; these
organisms have their optimum at higher temperatures. The most northerly of these
species, Ceratium arcticum, is found, it is true, especially at station 10, but in small
quantities compared with the numbers of Ceratium found in the coastal waters of
Europe. Only at station 14, where the surface layer has attained a temperature of
8-l°C, do we find any considerable quantity, especially of Ceratium longipes.

Cruise of the " Princess '" August 4 to 5, 1915 (Table 3).

On investigating the gulf of St. Lawrence in the first days of August we might
expect to find the results of the summer influence upon the plankton development
typically represented. The present investigation, however, reveals a remarkably poor
plankton. From what we know of the European waters, we should hardly expect, at
this season, to find any considerable quantity of diatoms; and they are also but very
sparsely represented in our samples. August should, however, be the right time for
Cilioflagellates, especially Ceratium and Dinophysis species. Of these, we find
Ceratium, fusus and longipes quite abundant at the two first stations (29 and 30) ;
otherwise, however, they are somewhat scarce. The genus Dinophysis is represented
by Dinophysis norvegica, the occurrance of which corresponds to that of the Ceratium
species. Ceratium tripos, which, with C. fusus, is distinctly euryhaline on the coasts
of Europe, is here altogether lacking, as also C. fxirca. Of infusoria, we find the
interesting Lahoea strohila abundant at station 29; otherwise all species occur but
sparsely. As, however, these samples were preserved with formalin, which is far less
calculated to preserve the more delicate forms than Flemming's liquid, the result may
be somewhat misleading in the case of the infusoria; with Diatoms and Cilioflagel-
lates, on the other hand, this method also is thoroughly efficacious.

As a general result, then, we may say that the phytoplankton of the area investi-
gated appears to be in quantitative respects considerably poorer than at the correspond-
ing season in the North sea; on the coasts of Europe, we find a secondary maximum
in September-October, when the surface layers are driven in towards the shores; and
we might expect to find something similar also on the other side of the Atlantic.
The present investigations seem to show that the general character of the plankton
has an annual periodicity similar to that noted on the coasts of Europe, though com-
mencing somewhat later, with the psychrophile species more predominant, while a
number of the thermophile forms of Northern Europe are lacking, or occur but
sparsely. The relative poverty in an area such as the gulf of St. Lawrence, which
with its rich supply of fresh water, should ofi^er, for the diatoms especially, good con-
ditions of nouT-ishment, is somewhat surprising; possibly it may be connected with the
rapid alterations in hydrographical conditions. On the coast of Norway, the develop-
ment of the diatoms commences in February, and not until May is the
rise of temperature in the surface layers so perceptible that the develop-

€ANADIAX FISBERIES EXPEDTTIOX, J91.'rlo 495

ment is arrested; in the gulf of St. Lawrence, the development can liardly be supposed
to begin before early May, and at the close of this month the rise of temperature in
the surface layers of the coastal water is distinctly apparent. On the other hand, the
summer temperature is not sufficiently high to favour the development of a rich
Ceratium plankton answering to the European plankton community called by Cleve
the " Triposplankton."

More than this we can hardly say on the basis of the present observations; they
represent a first commencement. As a necessary foundation for further studies, we
must first have observations carried out throughout the entire year from a number of
selected stations, so that we can obtain a clear view of the annual periodicity. In this
connection, it will be of great interest to have investigations similar in plan to
the present ones, repeated over a wider area at various seasons, but a continuous
investigation series covering the whole of the year should first be made, in order that
it may be possible to choose, for the more extensive investigations, the seasons at
which the most imix)rtant plankton communities are in course of development. Even
now we may say that it would be particularly interesting to have quantitative; investi-
gations of the plankton in the gulf of St. Lawrence and environs for the beginning
of May, so that we could determine the distribution of the rich spring plankton; the
investigations should preferably be combined with determinations of oxygen content
according to Winkler's method, as this would enable us to gauge the quantities of
organic matter produced by the phytoplankton during this rich period of development.

I have not considered it necessary at the present stage to give a list of the species
found and their synonyms. It will here suffice to refer to " Xordisches Plankton,'*
where the great majority of the species are described; to my paper on the plankton
production of the Xorth European waters in May, 1912^; and to Caroline Leegard's
work published at the same time (Untersuchungen ueber einige Planktoneiliateu des
Meeres." Kristiania, 1915. Nyt Magazin for Naturbidenskaberne, Bd. .j-j), with a
description of the Lahoea species and some related forms.

3 Joe. at.

6551—37

Table 1 (<i).— Dintonis, "Princess," June, 1915.

lATOMS, ■• PRINCESS ". JUNK. :

CosoioodlsDuit c
DipIonoiBBp.. .

Laudorliiicluiriiil
LoptocylindruH

Table 1 (W.— Cilioflaedlatn. 'Tmiii-ss," June, 1015.

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TABLE 1 (c). INrcSOKIA, ■' rRINCESS". JUNE, 1918.

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St. 4. May 29.

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Table 3.— "Princess," June, 1915.

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DEPARTMENT OF THE NAVAL SERVICE

CANADIAN FISHERIES EXPEDITION, 1914-1915

Investigations in the Gulf of St. Lawrence
and Atlantic Waters of Canada

UNDER THE DIRECTION OF

DR. JOHAN HJORT,

Head of the Expedition
Director of Fisheries for Norway

OTTAWA

J. DE L.ABROQUERIE TACH:fi

PRINTER TO THE Klxr.S MOST EXCELLENT MAJESTY

I'M;'