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Progress in 1964-65 at the
Bureau of Commercial Fisheries
Biological Laboratory, Honolulu

Thomas

A. Manar

Circular

243

February

1966

UNITED STATES DEPARTMENT OF THE INTERIOR

Stewart L. lUlall, Secretary

John A. Ciirvcr, Jr., Under Secretary

Stanley A. Cain, Ag.nxtanf Secretary for Fish and Wildlife and Parks

FLSH AND VVILDT.IFK SERVICE, Clari'iicc F. I'autzkr, Com»imiV„«.,-

Bureau of Commercial Fisheries, Donald 1.. .McKciikui, Dirertur

Progress in 1964-65 at the
Bureau of Commercial Fisheries
Biological Laboratory, Honolulu

Thomas A. Manor

Chief. Publication Sei\'ices

Bureau of Commercial Fisheries Biological Laboratory

Honolulu. Hawaii

Circulor 243

Wat?hington, D. C.
February 1966

ABSTRACT

This report deals with research results achieved by the
Bureau of Commercial Fisheries Biological Laboratory in
Honolulu from January 1, 1064, to June 30, 1965. Described
are developments in the following fields: the sensory capa-
cities of tunas: tuna behavior; subpopulations research
using genetic techniques; studies of the ecology of the ski])-
jack tuna and the albacore tuna: biological surve.vs of the
Indian Ocean; investigations of the oceanography of the
Hawaiian Islands area and of the entire Pacific: and studies
devoted to the evaluation of the use of a submarine for
research in fisheries and ocean()gra|)hy. Publications issued
or in i)ress during the period are listed.

INTRODUCTION

This report deals with research results achieved by the
Bureau of Commercial Fisheries (BCF) Biological Labora-
tory in Honolulu from January 1, 1964, to June 30, 1965.
Highlig-hts of the reporting period include:

1. Successful employment of new methods to maintain
living tunas in experimental tanks, a feat that has made
possible the first visual acuity curves and hearing curves
obtained from any of the several species of tunas; new
measurements of swimming speeds of tunas ; description of
the fish community around and near a floating object at sea;

2. Discovery and use of a highly sensitive new blood
group system for the identification of subpopulations of the
skipjack tuna;

3. Publication of a set of hypotheses that analyzes all
published material on the skipjack tuna to depict their
migrations in the eastern half of the Pacific; these hypoth-
eses suggest that the eastern Pacific and Hawaiian fisheries
are in part drawing on the same stock, a subpopulation that
is spawned in the equatorial waters south of Hawaii ; they
suggest also that the fishery reflects the passage of year-
classes of varying strength ;

rich, warm current that sweeps northward off the shores
of Japan ;

6. Surveys of the fishery resources of the world's third
largest and least known body of water, the Indian Ocean;

7. Commissioning of one of the Nation's finest oceano-
graphic research vessels, the Townsevd Cromwell, and her
employment ;

8. Conclusion of 16 month-long cruises in the Hawaiian
Islands as precursor to a larger investigation of the oceano-
graphy of the entire Trade Wind Zone, one of the most
ambitious projects in American oceanography;

9. Completion of an oceanographic atlas of the Pacific
Ocean, drawn from a massive amount of data collected dur-
ing the past 58 years and offering definitive depictions of
average seasonal conditions in the sea in layers of most
concern to the fisheries, those between the surface and about
5,000 feet ;

10. Research on a bold new concept in man's study of
the sea, a nuclear-powered submarine dedicated to research.

4. Analysis of the emerging tuna fishery of the South
Pacific ; establishment of a cooperative agreement between
this BCF Laboratory and the Nankai Laboratory in Japan
to carry out common studies of the Pacific's tuna resources ;

5. Representation of the interests of the United States
in international organizations designed toward the better
utilization of the marine resources of the Indo-Pacific region
and the conduct of a multination survey of the Kuroshio, the

Put more briefly, the period has seen significant research
on the fishes, the fisheries, and the sea. This report deals
with those topics in that order. To provide background for
the general reader, material is touched upon that deals
neither with the work of the past 18 months nor of this
Laboratory. Detailed descriptions of research methods have
been kept at a minimum, on the grounds hat the person
most likely to be interested in them, the specialist, will
have ready access to such material elsewhere.

FIGURE 1. Living tuiiu> fur behaviurul experiments are
collect oil b> expert fishermen <>f the HCS Laboratorv'?.
\e»sei (harlen //. (filbert. At ih*' left, the struggling tuna
is ^Huiig over the shipV rail us technician Haits t<i guide it
to the hdlfliiig lank. In the other photograph, the fish is
gently hxwereH into the fiber glass lank, where it will Hwim
free. The men are standing on the lid of the lank. The
Laboratory in Honolulu is the oiil> one in the world where
living tunas are regularlv available fur behavioral studies.

THE FISHES

The World of fhe Tunas

Fish and fish products, according to estimates of the Food
and Agriculture Organization of the United Nations (FAO),
provide man with 12 percent of the animal protein in his
diet. The percentage is small, but the surprising thing may
be not that men take so little of their food from the sea,
but that they are able to take so much, for the fish are
small and the ocean very large. Consider the catch of skip-
jack tuna, Katsuwoinoi pelamin (Linnaeus), in the Pacific
Ocean: About 100 million fish (550 million pounds) are
taken annually. These may represent one-tenth of the adult
population, which would then be 1 billion fish. These 1
billion skipjack are found in an oceanic area covering some
23-million square miles. If they were spread out evenly, like
checks in a plaid, then there would be one skipjack for each
0.023 square miles, or one for each 14.7 acres. To capture
3,000 of them, a relatively good catch, a boat would have
to collect every skipjack tuna in an area 10 miles wide and
69 miles long.

But fishes are not distributed evenly. They seek out areas
favorable for feeding or spawning, they gather in schools,
they migrate from place to place with the seasons. Commer-
cial fishing is possible only because over the millennia keen-
eyed fishermen have noted and taken advantage of recurrent

patterns in the behavior of fishes. Now these age-old obser-
vations are being extended and reinforced by the skills of
modern science.

During the past few decades, scientists have learned a
great deal about the sensory capacities of fish and how the
animals behave. Much of that knowledge rests, however,
on experiments with species that have little or no commer-
cial value, with the notable exception of the salmon.

Hindering efforts to conduct systematic experimental
studies of the food fishes of the open sea, such as the tunas,
has been the difficulty of maintaining the.se relatively large
and swift creatures in captivity. The Laboratory in Honolulu
has conquered this obstacle in a way that has made possible
several basic inquiries into the sen.sory capacities and be-
havior of tunas.

Several times a year, the Charles H. Gilbert, the smaller
of the Laboratory's two research vessels, no.ses alongside
the dock in Honolulu carrying on her deck a cargo of what
look like oversized bathtubs with lids on them (fig. 1). A
complex of water hoses runs to and from the tanks. P^ach
container carries 5 to 10 live tunas caught only a few hours
previously by the Gilbert's crew of expert pole-and-line
fishermen.

KKrl RE 2. Eve»ifehl [ilavs a significant role in lht> behav-
ior of tunas. The ^^tear*'' in the eve of this skipjack is an
artifact; it is u drop of water that remained when the fish
u;ts taken fri»iti the lank for photography.

The Gilbert's arrival is the signal for a crane operator to
stand by. Fishery scientists fit a bridle to the "bathtub"
tanks. One at a time, the tanks are lifted from the deck and
taken to the 24-foot plastic swimming pools that are part
of the Laboratory's complex for behavioral research. There
the lids are unbolted. The crane lifts the containers and
then lowers them into the sea water pools. Fishery scientists
carefully tip the containers to let their living cargo swim
free.

Such painstaking methods have had impressive results:
the Kewalo Basin facility often has as many as 60 or more
tunas waiting their turn for behavior studies. Thus this
Laboratory has become the only one in the world where
living tunas are regularly collected and held for study. The
procedure for handling the fish was worked out by biologist
Eugene L. Nakamura. One of the technological triumphs
of the Laboratory has been its ability to keep skipjack tuna
alive for several months. Prior to our improved handling
methods, the skipjack usually dashed themselves to death.
Now specimens -have been kept alive as long as 6 months
in the Laboratory's tanks.

Only since Nakamura perfected his methods of handling
have he and other behavioral scientists in the Laboratory
been able to conduct controlled experiments with tunas.
Already several scientific papers have been prepared, each
of them revealing previously unknown facets of behavior.
Currently underway are studies of how well the fish see and
hear and how they are able to maintain swimming depth.
From the broad base of such information may come new
and unconventional methods of catching tunas for commer-
cial purposes.

How Well Do Tunas See".'

How well tunas see has obvious implications for the

fishery. Experiments in the lucent waters of the central

Pacific a few years years ago proved it well-nigh impossible

to catch skipjack tuna in any numliers with a monofilament

FI(>1 RE ^{. Vi»ual ucuily depi-nds upon iht- liri^htiu'»» of
:\n objert. This figure cftnipares llit- \i»u!il aruilie«« «if
>t'lloMfiii. skipjack, and littl*- 1uiin>.

gill net; they dodged it easily. Ob.server.s .stationed at the
underwater ports of the Charles H. Gilbert and Toinixend
Cromwell have marked the apparent importance of vision in
feeding behavior.

Eugene Nakamura has now measured the visual acuity
of three species of tuna: skipjack, yellowfin, Thiouuis
albucare.i (Bonnaterre), and little tunny, Euthynnus ajfinis
(Cantor). His experimental apparatus and methods were
described in the Laboratory's last progress report. Briefly,
the fish are taught to respond to a pattern of black-and-white
stripes presented on a square of illuminated opal glass.
Reward (food) follows one pattern, punishment (a mild
electric shock) another.

The characteristic being measured is visual acuity, which
is one of the several elements of visual perception. Tech-
nically, visual acuity is "the reciprocal of the minimum
visible angle measured by minutes of arc." This measure of
visual perception depends upon the brightness of an object.
As the target becomes dimmer, details tend to blur.

The yellowfin "sees better," in this sense, than the skip-
jack, and the skipjack better than the little tunny (figs. 2, 3,
and 4). Comparative size may have something to do with
these results, a possibility Nakamura is now investigating.

It will be some time before these studies can be extended
to the other elements that sum up the visual experience:
the responses to color, form, size, number, position. Yet it is
only in such a painstaking way that quantitative studies can
be carried out.

A brightly lighted square of opal glass striped black and
white is obviously nothing that a tuna is ever likely to
encounter in its natural environment. Experiments of this
nature represent only a first step toward an understanding
of the role that sight plays in the life of the tuna. Neverthe-

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less, it is a step that has needed taking. Equally desirable
have been investigations of the responses of tunas to another
stimulus that is also unknown in the sea — pure tones, the
sort of tuneless "beep" with which television stations signal
the passage of the hour.

'1

52FTV LITTLE

TUNNY

SKIPJACK

FUil'RE 4. At a constant brightness, a ,^ellowfin sees
details of an .olijcct better than a skipjack nnrl a skipjack
belter than a little tunny.

How Well Do Tunas Hear?

All man's ingenuity has failed to greatly improve his
ability to see underwater, yet with the aid of relatively
simple instruments, he can hear across oceans. Sound travels
fast and far in the sea, obeying physical laws that are well
defined. The explosion of a 1-pound charge of dynamite
off the Hawaiian Islands has been picked up by hydrophones
on the Caliiornia coast.

The first quantitative measurements of the hearing capa-
city of a fish were made in the 1920's. The creature was a
goldfish, and it responded to frequencies between .32 and
2,752 c.p.s. (cycles per second). That is, it could hear sounds
so low that men could scarcely hear them but was unable to
hear high-pitched sounds common in the human experience.

Despite the worldwide interest on the part of scientists
and the fishing industry in the use of underwater sound to
attract or repel food fishes, little quantitative research has
been performed on the hearing abilities of the creatures.
One rea.son may be that such knowledge is only slowly
acquired because it is dependent on training the animals to
respond to signals that offer punishment or reward. During
the past months, Robert T. B. Iversen has recorded several
hearing curves for yellowfin tuna. No such curves are avail-
able for any other member of the scombrids — the large and
commercially important family to which the tunas belong.

Iversen has shown that the yellowfin tuna hears well at
frequencies from about 100 to 2,000 c.p.s. Its hearing is
most acute between 350 and 800 c.p.s. (fig. 5). Many sounds
in the sea that might be expected to have biological
significance for tunas are contained within that range.
Examples are the sounds made by small fish swimming
and by schools of squid. Iversen has been measuring audi-
tory "thresholds," the minimum intensity at which the
yellowfin tuna can hear a sound of a particular frequency.
He has not yet ventured into other aspects of hearing, such
as directional orientation, the ability to locate the source
of a sound.

Although tunas respond to sound, there is only the
slightest evidence that they themselves produce sound. That
fish make sounds men can hear was demonstrated to science
101 years ago. (Fishermen had known it for untold
millennia). Since the advent of sensitive hydrophones,
scientists have learned that the sea is quite a noisy place.
Many laboratories possess tape recordings of the hissings,
grunts, squeaks, and moans that contribute to the totality
of audible sound in the ocean. The living sources of some
of these have been identified. The carangid Trachurus
tiachurus Linnaeus, for example, is known to make "sounds
like those produced by running the fingers along the teeth
of a comb."

Yet from the experimental work to date, one would think
that the tuna, which is demonstrably far from deaf, is com-
pletely silent. A biological sound produced by its own kind
might well be of importance in the behavior of tunas, but
whether such a sound is produced is uncertain.

Maintaining Swimming Depth

Visitors to the Kewalo facility, watching the tunas con-
tinuously circling the tanks, are likely to ask two questions:
"Do they always swim in the same direction?" and "Don't
they ever stop swimming?" The answer to both questions
is "No." The fish do change their direction of swimming.
And never do they cease to swim, although normally they
swim only slowly.

For swimming, to the tuna, is far more than a method of
getting from one place to another. It is as vital to the fish
as breathing is to a man. If the tuna stopped swimming, it
would suffocate. And since the density of its firm body is
slightly greater than that of sea water, the fish would also
sink.

The Kewalo facility allows exact studies of the swimming
speed of tunas as it is related to the needs for ventilation
of the gills and the maintenance of hydrostatic equilibrium.

John J. Magnuson has found that the little tunny circles
the tank at 0.75 meter second (about 1.5 m.p.h.) both day
and night. When the fish were deprived of food for several
days, their speed declined to 0.55 m. sec. (about 1.1 m.p.h.).
The little tunny feeds by day. If the search for food played a
pi'edominant role in establishing swimming speed, one would
expect the fish to swim slower by night; and certainly one
would expect that the creature starved for several days and
questing for food would swim faster than the satiated
one. The little tunny, however, show^ed neither behavior.
Whether the minimum speeds reached were chiefly related
to a single function — gill ventilation or hydrodynamic lift —
Magnuson is not yet sure. For some tunas, there is evi-
dence that the requirements for gill ventilation are .some-

30

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50

100

200 300 400 500

CYCLES PER SECOND

1000

FIGl RE 5. Thf >rlIo»*Jin hear^ brwl sound> that arc near
."jOO r.p.s.. as is shown by the dip of the hearing curve at
that freqiienry. Sounds of this frequenrv are common in
the sea. An example is the sound pr«»duced h> a school :>f
small fish swimming.

what less than those for hydrodynamic lift, which means
that the fish would sink before it would suffocate.

Magnuson's research, summarized very briefly here, has
turned up one interesting if probably not too important
bit of information : when he began to measure body density,
he discovered that the little tunny in the laboratory tanks
were slightly less dense than those fresh from the sea, most
likely because of the presence of more lipids in their flesh —
the creatures seemed to be getting fat on their shoreside
diet.

The Fastest Fish

So far as this capability has been measured, the tuna
seems to be one of the fastest fish. It ranks with the cheetah.

1 K

the eagle, and the dragonfly as among the swiftest creatures
of their kind on earth. Most of the time, however, in tanks
at least, the tunas swim rather slowly. Rates reported from
studies at sea vary widely.

The presence of underwater viewing ports on the Charles
H. Gilbert has enaVjled our Laboratory scientist Heeny S. H.
Yuen to make quantitative studies of the swimming speeds
of yellowfin and skipjack tunas in the ocean. The procedure
for finding these speeds is ingenious: the fish are photo-
graphed with a 16-mm. camera; from calculations that take
into account the speed of the camera, the ship's forward
movement, and its roll, Yuen is then able to measure suc-
cessive images on the film in such a way as to arrive at a
realistic estimate of the actual speed of a fish that may have
appeared within the viewing range of the camera no more
than half a second (fig. 6).

In this manner, he has made 510 measurements of the
swimming speed of feeding skipjack tuna from four .schools
and 33 measurements of yellowfin from a single school.
These results were then treated statistically to determine
the validity of some of the relations suggested by the data.

The swimming speeds of the yellowfin tuna so measured
were from 1.6 to 5.4 m. sec. (3.2 to 10.9 m.p.h.). These
results fall between those reported for yellowfin swimming
at a depth of about 350 feet (2 m.p.h.) and struggling at
the end of a fishing line (40.8 m.p.h.).

The swimming speeds of the skipjack tuna (0.3 to 6.9
m. sec, or 0.6 to 13.9 m.i).h.) are much lower than those
found by other researchers (about 10 m. .sec, or 20.2 m.i).h.) .
The reason for this difference is unknown.

Both species swam faster (covered more body lengths)
at the tailbeat rates measured than did the few other kinds
of fish studied by earlier workers.

Kl<;i KK 6. Till' «>iimmin)s >|><'»'d» of luiias al >fa havo
ln'iii i'<>iii|iul<'il frimi the moxiiwnl of the lUh from fraiiw
li> fruiiu- on iiiolion piiliirt- film lak<-ii from ihi- >i<->«iii(5
rliaiiiliiT-. of till- ( liiirlfH II. *.i(/><Tl.

BIRD FLOCKS

CONVENTIONAL
PULSED SONAR

FREQUENCY
MODULATED SONAR

FIGL'RE 7. The new continuous-transmission, frequency-
modulated sonar to be installed aboard the Toirnsend
Cromwell will allow scientists to track individual fish and
fish schotds underwater. To locati* tuna schools the com-
mercial fleet now depends heavily on sighting bird flocks.

which are associated with the schools (left). Conventional
pulsed sonar (center) locates schools but cannot keep them
under constant surveillance, as can the frequency-modulated
sonar (right), which opens up wide areas of the sea to
the scientists.

Although the observations just described tell us how fast
individual fish swim, they say nothing about the speed of
schools as units. What these speeds are, whether the fish
school at night when visual contact may be lost, what
depths they may prefer — these are unknown factors at
present. They may not remain so. In spring 1966, the
Townsend Cromwell will take to sea for the first tests of a
new sonar system that is now being constructed in California
for the Laboratory in Honolulu and that will be installed on
the vessel early in 1966.

Unknown to the fish, long beams of unheard sound will
play upon creatures almost a mile away from the ship and
far below it. The echoes of these beams, received by sensi-
tive electronic equipment aboard the vessel, will give scien-

tists a new dimension to their picture of life in the open
ocean.

The sonar will be a continuous-transmission, frequency-
modulated equipment operating in two ranges of frequencies
(fig. 7). This sophisticated gear was chosen instead of the
more conventional pulsed sonar because it allows a target
to be kept under constant surveillance. Its use lessens the
probability of "losing" a target. The equipment will have a
range of about 1,000 feet on individual tunas and perhaps
5,000 feet on a target of suitable strength — for example, a
school. It will be capable of high resolution, distinguishing
between fishes 7 inches apart at 300 feet.

And a still more exciting prospect looms ahead — the
possibility of the construction of a nuclear submarine

Fliil. RF- 8. Tht' rafi .\<>n«*» offers crampoH quarl«T> to the
objicrvrr, who >il> in a wiiiHonod cai^'-on with a 360-d('gree
\i('\% of ihi" *irran art>un(l him. Thr rafl ha> i»ro\<'d useful
in sluHies of ihe fi^h cominunilies of the upper laver of
lh<> oe<>an.

especially designed for fishery-oceanography research, the
first nuclear submarine to be used for nonmilitary purposes.
All the advance planning for this addition to the Nation's
research capability has been done at our Laboratory and
will be di.scussed later. Obviously, the submarine will have
enormous possibilities for enlarging man's knowledge of
the behavior of creatures in the sea.

The new sonar and the research submarine — these are
exceedingly complex instruments for research. They make
demands on many types of technical skills and cost a great
deal of money. They are characteristic of much of the con-
duct of science of the latter half of the 20th century. But
complexity and great cost are not necessarily the sole hall-
marks of progress. The past months have seen some good
science done at our Laboratory with a piece of equipment
that was technologically feasible at least 2,000 years ago
when Alexander the Great made his celebrated descent in
a diving bell to the floor of the Mediterranean.

A Log With a View

Fishes collect around logs and other flotsam at sea. This
habit is commonly exploited in sport fishing, and some small
commercial fisheries have been based upon it. A few years
ago, Reginald M. Gooding built what is essentially "a log
with a view," a small raft equipped with a many-windowed
caisson beneath the waterline. Tested first off the island
of Hawaii, the raft Nenue proved seaworthy. The informa-
tion she provided was found worth collecting. Early in 1964,
the Nenue was shipped aboard the Churles H. Gilbert to
equatorial waters. There she undertook two drifts, one of
8 days, the other 9. During daylight, she was manned at
all times by two observers. Among them, Gooding, Magnu-
son, and Randolph K. C. Chang .spent 276 hours observing
the behavior of fishes under the dazzling canopy of the sea
surface (fig. 8). The raft allowed them to obtain some
striking photographs (fig. 9).

What did they find? When the raft was first put in the
water, no fish were to be seen. Within 10 minutes the first
of them arrived, little rudderfish that are cousins of the
Hawaiian nenue for which the raft is named. Dolphin fish,
known as mahimahi in Hawaii, appeared. They mingled
with triggerfish, close relatives of the Hawaiian humuhumu-
nukunukuapuaa, and many others. Within a short time,
numerous fishes had been sighted. By the end of the longer

10

drifts, almost a thousand fishes and some other creatures
were swimming within sight. Many of the same species
are present in both the Hawaiian and equatorial localities.
The length of these creatures ranged from a few inches to
several feet. The observations on these drifts constitute
the most exhaustive study yet made on an underwater
community in the open sea.

These raft studies and those described earlier have dealt
with individual fish or at the most a few thousand, the
school. Between the school and the millions of fish that
make up the total population of a single species lies anothei-
natural unit of study, the subpopulation, a group of geneti-
cally related fishes. Its dimensions are as yet unknown,
other than that they must stand somewhere between the few
thousands of a school and the many millions of a species.
The relatively recent application to fisheries of techniques
of genetic research that have proved their value in agricul-
ture and animal husbandry, as well as in the treatment of
human illness, is now providing a powerful tool for under-
standing some of the fundamental jjroblems of fishery
utilization.

Blood Kin

The water that Hows through a tap may have come from
a single reservoir or from one fed by half a dozen streams.
In a like manner, the reservoir of a species of fish that is
sampled by a fishery may consist of groups from many
sources. Such isolated, interbreeding stocks of fishes (or
other animals) are called subpopulations. Many lines of
evidence have strongly indicated that fished populations are
not as a rule homogeneous, like water from a reservoir fed
by a single stream, but consist of several subpopulations
that breed separately in different places and perhaps at
different times of the year.

Evidence for the e.xistence of subpopulations has come
from morphometries, the study of the physical character-
istics of the fish, from mathematical treatment of statistics

■"//«.

i^-T^

FKfI KK 9. >\ hitelip sharks (Carcharbinus tttuffhiKtiius)
photugraphrfl from lh<* rafi .\*>fiu<'. Th*- >lript-(l fish**» a^<^
pil4>tfi>li<'^ ( ytiucrntfs tluctor) thai arronipaiiv iUv sharks.
\ i>ibl> altai'hfil Ui ill** sharks ar«* surkcriish. Rentttra
rt'itiarn. Sharks fm|uenll> approa*-h«-cl thf .\**iim#'. a^ <lifl
a scorr <»f ijthcr (ishfs.

on the catch, and from tagging studies. Morphometries
offer many interesting clues to the existence of subpopula-
tions but have the shortcoming of dealing with character-
istics that can be drastically modified by the environment;
size is an example, for fishes of the same sjiecies can grow
at different rates in waters of different temperatures, and
these differential rates have not been shown to he linked to
inheritance.

Catch statistics, again, provide inconclusive evidence. Arid
tagging studies, which usually are made for estimates of
population size and mortality rates, rather than for sub-
jxiijulation research alone, are both slow and expensive.

11

Shortly after the discovery of human blood types at the
turn of the century, Japanese scientists began to seek
similar factors in fishes. These investigations were not
aggressively pursued on an international scale, however,
until the 1950's, when several U. S. investigators, including
Lucian M. Sprague, now with the BCF Laboratory in Hono-
lulu, took up this line of research.

Like men, like cattle, like most other creatures relatively
high on the evolutionary scale, fishes of the same species
may have different types of blood; this fact has given sub-
population research a new dimension. Here is a "tag" that
is built in, that is inherited and unalterable.

Within the past decade, an entirely new and e.xtremely
active area of research has opened up, and the geneticist
has entered the ranks of the marine professions. Recogniz-
ing the importance of the early findings, our Laboratory
entered the field in 1960 and since then has become a world
center for research on the blood groups of tunas (fig. 10).
Its accomplishments have been described in several scientific
papers and note«t in previous progress reports. They are.
briefly, (1) use of a number of systems, but mainly one
called the B system, discovered by Sprague, in studies that
showed that the Hawaiian fishery drew not on a single
population of skipjack, but several; (2) determination,
again largely by use of the B system, that as many as seven
subpopulations of skipjack may exist in the central Pacific
from Hawaii to Tahiti; (3) discovery of an A-B-0 system
in the bigeye tuna, a system named after that most familiar
in humans and resembling it in that it is determined by the
inheritance pattern of three related allelic genes; and (4)
the finding of blood group systems in the yellowfin and
bluefin tunas.

h'Hwl UK 10. AfitT thvy hH\e b^'^n Ivpt-d, !4«>nie blood ,
!-uiiipb'^ Hrt- frozen in a ((Urfriii solution f*»r lalrr ust* in
>liinHiir(li/-ing rfa|E<*i'l^. H«'r<' u U-chnician ^>rin|[*"> blood
into solution ihat will b#- fr«»/*-ii.

12

In Slimmer 1964, Kazuo Fujino. internationally known for
his studies of the genetics of whales, joined the staff of the
Laboratory in Honolulu to head the work on subpopulations.
The discovery by Fujino and his colleagues of a highly
sensitive new blood group system for distinguishing sub-
populations of the commercially important skipjack tuna
has highlighted recent blood group research at our Labora-
tory. This new system is called the Y blood group system.
(As with most blood group designations, the name is arbi-
trary). What the Y system offers is an opportunity to
examine any sizeable portion (100 or more fish) of the
skipjack population and determine mathematically whether
it represents a single subpopulatiun. It supplements earlier
systems and. in recognizing several more and e.xtremely
subtle differences in blood types than the others, holds forth
the promise of differentiating subpopulations that are closely
related. To date, tests of the Y system have shown the
existence of 15 kinds of "Y" individuals among skipjack.

It is the proportion of each of these kinds of "Y" types
in a sample that allows scientists to delineate subpopula-
tions. A single system is often not adequate, hence the
merit of several. The Y system of skipjack blood will thus
not replace the B and other systems already used but sup-
plement and extend them.

The geneticist drawing his samples from the commercial
fisheries can distinguish subpopulations, but he cannot deter-

mine the place of their origin. To do that, he must have
samples from far afield. For this reason, our Laboratory
has collected samples of tuna bloods from throughout the
Pacific.

The blood group studies represent the apijlication to
fishery problems of principles and techniques pioneered in
other fields. Another technique of genetic research on
human beings that has recently come into use in fishery
work is the study of the sera of fish bloods. Certain inherited
components of the clear fluid of bloods can be distinguished
by a method called starch gel electrophoresis, which relies
on the diflferential response of certain proteins in the serum
to an electric current. Fujino and his associates have used
this technique to locate two types of proteins in the sera
of both skipjack and yellowfin tunas. They have found three
phenotypes that allow the rigorous mathematical analysis
upon which conclusions concerning subpopulations are based.
An additional, very rare phenotype has been observed in
the skipjack tuna.

Research on subpopulations deals with fish in units of .r
thousands to .r millions These units in their totality con-
stitute a species. And it is with the concept of species that
both fishermen and fishery scientists are most familiar. At
our Laboratory, two species are of special interest, the
skipjack and the albacore tunas, both of which form the
basis of large U. S. fisheries in the Pacific.

THE FISHERIES

The Catch of Tunas

Two hundred sixteen countries have commercial fisheries,
but pickings are small for many of them. In 1963, the most
recent year for which reliable statistics are available, two
I'acific nations, Japan and Peru, took almost one-third of
the world's 51.1 million ton harvest of the sea, according
to FAO.

By weight, the tunas (or FAO's "tunas, bonitos, and
skipjacks") do not bulk large in the world catch, accounting
for only 3 percent of the total, or 1.4 million tons out of 51.1.
They are among the most highly prized of fishes, so that in
value to the fishermen they overshadow many others caught
in greater quantities. In California in 1964, the four main
species — albacore, bluefin, skipjack, and yellowfin — com-

13

JAPAN-

UNITED STATES
PERU

"ALBACORE"

JAPAN -

UNITED STATES
PERU

BONITO"

JAPAN

UNITED STATES
PERU

JAPAN

UNITED STATEr
PERU

40 60 80 100

THOUSANDS OF TONS

120

FKil RE II. Thi' ruli'li uf lullu^ uiiil luiialiki' fi!-h<-> in llic
PjirifM- Orraii ar<-iuinl> f<»r about c>n«'-lialf of llw worM's
total for lli<*M* ^|M•«•i€*^. licrt- ar*- >lio\«i) 4-;itrhf> <if I'lTil,
Japan, and tin- 1 liitrd Statr^ for I96.H. Sinirr<-> of the ilala

:ir.- tlu' KAO I96:{ '^.arl k of KMi.r> Stali>li<".. \ i,\. 16.

and niatrrial from tin* !Naiikai Kcgional h'ivhrri4'> l{r>4*ar<-l)
Laboratory, Japan.

1 A PAKI

i

UNITED STATES

BIGEYE

1

PERU

1

J

1

UNIT© STATES

■■

"BLUEFIN

1

1

140

TABLE 1. Catch (in thousands of metric tun>>) of major
tuna and lunalike specie;" bv Japan, United Slaloji, and IVru
in Pacific Ocean, 1963. Sources: FAO Yearbook, Vol. 16,
and INankai Hegional Fisheries Research Laboratory, Japan.

Japan

■nited States

Peru

Total

30.3

107.7
110.2

15.8

51.1

100.0

100.0

52.2

18.6

704.8

55.0

12.3

195.2

153.3

130.9

140.6

Albacore 77.4

Bigeye 110.2

Bluefiin 35.3

Bonito

Skipjack 124.4

Yellowfin 73.3

Total 420.6

manded prices ranging between 3200 per ton for skipjack
and $350 per ton for albacore, against $47.50 for Pacific
mackerel and jack mackerel. Similar disparities exist in
other countries. In Peru, tunas in 1963 commanded a price
per ton nine times that for the average of all other marine
products and in Japan, about three times.

Although tunas are found all around the globe and are
an important element of the French and Spanish landings,
Japan, the United States, and Peru have the major fisheries.
These three, in 1963. took 75 percent of the recorded world
catch of tunas: Japan, 677,100 tons (half the world catch) ;
the United States, 162,000 tons; Peru, 130,900 tons. The
total value to the fishermen was: in Japan $209 million, in
the United States $45 million, and in Peru $10 million. In
dollar values, the tunas formed the base of the most impor-
tant fishery in Japan, the second in Peru, and the third in
the United States, where they were exceeded only by shrimp
and salmon.

The Japanese fishing fleets range the Pacific, Atlantic, and
Indian Oceans, so that the 1963 total of 677,100 tons repre-
sents a worldwide catch. Recently the Nankai Regional
Fisheries Research Laboratory has made data available that
allow the separation of statistics on fishes caught in the
Pacific from those caught elsewhere. These figures show

that in 1963, the total Japanese catch in the Pacific of the
major tuna species was 420,600 tons, 64 percent of all Japa-
nese tuna landings. The U. S. Pacific total was 153,300 tons.
the Peruvian 180,900 tons. The Peruvian catches were
dominated by the tunalike bonito, which are not taken in
quantity by the United States and Japan. Thus about one-
half (704,800 tons) of the world's catch of tunas comes
from the Pacific Ocean (table 1 and fig. 11).

At the BCF Laboratory in Honolulu, investigations are
now concentrated on two species, the skipjack and the
albacore. Honolulu is located a little to the south of the
North Pacific albacore fishery but within the spawning
grounds of the species. With regard to the skipjack, Hawaii
stands at what may be either the terminus of a migration
of enormous dimensions or merely the center of a commuting
web; or, like Grand Central Station, it may partake of the
nature of both. Within a few miles of its shores lie the
boundaries of two of the great water types of the Pacific
Ocean, and the State itself is bathed in summer by one
of the major oceanic currents, a circumstance that may have
a profound significance in tuna studies. The local fishery
affords scientists an opportunity e.xcelled nowhere else in
the world to collect living tunas and to observe the conduct
of a year-round fishery. And near Hawaii lies a hidden
tuna resource of immense potential value.

The Skipjack Tuna

The name "skipjack" has been applied to several species
of fishes that jump above or play at the surface of the
water. The tuna that is called "skipjack" is found and
fished in all the world's oceans except the Arctic. There
are names for it in at least 20 tongues.' In 1'.h;:'>, the
skipjack tuna outranked in weight all other tunas caught
in the Pacific (table 1). The skipjack is a short-lived
fish and has a dark blue back and a silvery belly. It
attains a length of about 30 inches. There are at least

three cogent reasons for the study of the skipjack: the
commercial importance of the present fishery ; the much
greater potential commercial importance of the species; and
the growing possibility that elucidation of some of the
mechanisms that link the skipjack and its environment in
the central Pacific may give results that could be applicable
to fishery problems throughout the world.

The Aku Fishery

The Hawaiians have a name for the skipjack tuna that
is halfway between a cough and a sneeze — "aku." The aku
catch is by far the State's largest, accounting for 69 percent
of the total landings of 5,874 tons (about the average annual
catch) in 1963, according to the Hawaii Division of Fish
and Game. The skipjack are caught in Hawaiian waters
every month in the year, but the fishery depends heavily
upon the larger fish that are most often in evidence during
the summer.

The Hawaiian aku fishery is conducted by the sampan
fleet, the size of which has been dwindling with the years,
although catches have not paralleled this trend. Fishing is
done by pole and line. Usually schools are located by observ-
ing bird flocks. The schools are chummed with live bait, by
preference the "nehu" or anchovy ( Stolephorua purpureus) .
Landings have varied from 29,000 pounds in January, tradi-
tionally one of the poorest months, to more than 3 million
pounds at the height of the season in July, according to
Richard N. Uchida, our Laboratory scientist who has made
a definitive statistical study of the 1952-1962 catch.

'These ini'lude patois of ihe ItritUh West Indies (barriolcti ; Sinhale.se t ulai;utlura t :
Chinese (tow chun^i ; RnKlish (skipjack tunai ; Spanish latunl ; Danish (buKstribet
bimit) ; f reni'h (bonili- a ventre raye) ; tlerman (bauchstreifiirer I ; (ire<?k (l)elamy^t ;
Hiiwaiiiin laku) . Arabian ibnlanidal : Japanese ikatsuui : lndune»ian itjakalanKi :
NiTwivian ami Sw«lish ibonitl ; Ta^aluK (galyasani ; Portuguese (gayadu) ; Tunisian
ibiius^enui . VuKuslavian ilrup prutfavaci. The scientific name is almost equally vari-
ous, there are li» versions, of which Kat^uunnuH ^*-"umi,s is most generally usel.
( Kosa, Horaciu, Jr. I'.TiO. Scientific and common names applied t<i tunas, mackerels.
;ind spear fishes of ihe worhi. with notes on their j:e"krraphic distribution. KAO.
Washington. D. C.i

IS

As predictably as tourists flock to the famous beaches
of Waikiki in summer does the skipjack catch rise in the
warmer months. Both tourists and tunas are a source of
income to the State of Hawaii. (But tourism is a $200-
million-a-year business ; the fishing industry brings in about
$1 million to the fishermen.) The arrival of both tourists
and tunas in Hawaii is predictable. Unpredictable are the
numbers in which either will turn up. May 1965 was a
phenomenal month for the skipjack fleet. Ofl'icial figures
are not yet available, but it is no secret that in May the
fishermen had a month such as normally occurs only at the
peak of the season. July. In fact, this May's catch was
estimated to exceed that of most July's. Fishing almost
within sight of Waikiki, the sampans came home night
after night heavily loaded with aku. And the captains of
the Laboratory's research vessels reported that the fleet
was only nibbling on the population ; schools were abundant
offshore for many miles to sea. In June the catch slackened,
but Hawaii still appears to be headed for a record year.

The unusual, catch in May could be attributed to two
causes. First, it may have represented the passage through
the fishery of a year-class of great strength. Year-classes
of almost legendary abundance are well documented in many
fisheries. Like comets and great men, they appear so briefly
and infrequently as to be remembered long afterward. The
much studied 1939 year-class of sardines off the west coast
provides an instance, as does the classical 1904 year-class
of Norwegian herring. Second, the May catch might have
reflected the response of the skipjack to some change in
the ocean environment. These two posibilities are not
mutually exclusive, of course.

Aku Forecasts

As has been mentioned, the Hawaiian Islands lie near

the boundary between two water types. It is a boundary

that, like the front line in a stalemated war, shifts back and

forth. Thus the islands are bathed by water of relatively

high salinity during part of the year, by less saline water
during the rest. Normally, but not always, the more saline
water prevails during the fall and winter, the less saline
during the late spring and summer.

Good fishing seasons for skipjack tuna are often charac-
terized by a flow of less saline water about the islands. This
circumstance is interesting but of little predictive value to
the fishermen, for by the time the less saline waters arrive
off Hawaii's shores, the fish are there too. Our Laboratory
scientists have noted, however, what appears to be another
characteristic of good fishing years: the seasonal warming
of the sea surface starts early.

Using the time of initial warming, as measured at Koko
Head, the southernmost point of the island of Oahu, and
information on the changes in salinity near the islands,
oceanographer Gunter Seckel for the past 6 years has
issued an "aku forecast" in April. The season has usually
borne out the forecast. The forecast for 1965 called for an
"average or above average" catch, and the fishery is un-
deniably headed that way.

These forecasts are of more use to the scientists than
to the fisherman. "Below average," for example, a term
as exact as the scientists are yet prepared to use, could mean
anything from rather poor to catastrophic, a Ijig difference
to a man trying to make his living from the fishery. To
the scientists they provide clues to the natural jjrocesses
that may account for the variations in the skipjack catch,
and these clues are being followed up.

The phenomenal catch in May provided a dramatic illus-
tration. The salinity value of ;M.8 ",,,, (parts per thousand)
has been empiiucally selected as that separating "favorable"
from "unfavorable" waters. Figure 12 shows that when
the salinity at Koko Head dropped below this value, and
stayed there, the estimated skipjack catch rose abruptly
and although landings declined in June, they remained well
above previous levels. The estimated monthly take of skip-

16

jack tuna from January through April was between 300,000
and 800.000 pounds per month. Then in May the catch
increased to an estimated 3.5 million pounds and in June
was 2.3 million pounds. For the first 4 months of the year
average salinities at Koko Head were about 34.99 ",,,,. drop-
ping- to 34.65 Villi in May and June.

On the basis of previously established criteria, the waters
changed from what is designated as an unfavorable type
in April to a favorable type in May. From the weekly
landings and the biweekly salinity samples one can see that
the change must have occurred about May 5. The salinity
was 34.99 Vim on May 4, dropped to 34.69 ",,„ on May 7 and
34.53 ",„, on May 11. For the 7-day period ending on May 3,
the estimated Oahu landings were 130,000 pounds, for the
7-day period ending May 10, they were 510,000 pounds.

This correlation supports the hypothesis that water type
is important in the distribution of skipjack. It should be
emphasized, however, that the correlation is between type of
water, of which the salinity is merely an inde.x, and skipjack
catch — not between salinity itself and skipjack catch. The
decline in the catch rate in June, when salinity remained
low, shows that other factors also affect the availability of
skipjack.

Skipjack Hypotheses
Theoretical studies of the origin of the skipjack caught
by the Californian and Hawaiian fleets may seem remote
from the immediate interests of the fishery. Yet until it is
known where and when the fish are spawned and in what
quantities it will be mosi. difficult to arrive at valid sugges-
tions for rational management of the resource. Since fishery
scientists, dealing with matters that vitally affect major
industries and international relations, only cautiously put
forward general theories on the basis of evidence not
wholly and repeatedly substantiated, there exists no gen-
erally accepted "skipjack theory." This reporting period,
however, has seen the publication of a scientific paper by

Brian J. Roth.schild that considers all of the available data
on the skipjack tuna and advances a set of interlinked
hypotheses to explain some of the enigmas of the fluctua-
tions of the skipjack catch. These hypotheses are not yet
a theory, but constitute a bold and significant first step
toward one, and almost all research on the skipjack in the
next few years will need to take them into consideration.

In brief, on the evidence of data on spawning, size distri-
bution, movements, and gonad indices, Rothschild hypo-
thesizes that the small skipjack that make up the bulk of
the eastern Pacific catch are spawned not in those waters
but somewhere in the central Pacific and that they immi-
grate to the shores of the Americas at an early age, stay

jmm

FIGVRE 12. The ai-rhal of water of lower »altnitv at
Oahu rail signal g<»od skipjack catches. Here are shown the
average nionthlv salinity values at Koko Head from January
through June 1965 (the line) and estimated a>erage skip-
jack catches (bars). Note that as salinitv dropped. es|i.
mated skipjack catches increased.

17

MARQUESAS ZONE

170' 160* 150' 140' 130° 1^0' IIP* 100* 9p° 80' W.

FIGURE 13. In a paper published during this reporting
period, one of our scientists hypothesized that the large
I'. S. fishery for skipjack tuna in the eastern Pacific
depends upon fish that are spawned in equatorial waters
south of Hawaii. The skipjack remain in the fishery area
only a short while, returning to the equatorial Pacific to
spawn. The Hawaiian skipjack fishery may also depend to
some extent on fish spawned in the Equatorial Zone.

there briefly (no more than a year), and then return to
the central Pacific.

On the basis of subpopulation studies and other evidence,
he suggests that the skipjack caught in Hawaiian waters do
not comprise a single population unit. He postulates that
the central Pacific spawing area can be divided into three
adjacent zones, one lying near the latitude of Hawaii, an-
other around the Equator, and the third south of the
Equator near the Marquesas. The fish spawned in this last
zone, he says, probably do not enter the eastern Pacific
fishery. He seeks to determine whether the skipjack caught
by the U. S. fishery in the eastern Pacific originate for the
most part in the Hawaiian or the Equatorial Zone. Several
lines of evidence suggest the conclusion that they come from
the Equatorial Zone.

Some of the skipjack in the Hawaiian catch do not orig-
inate in Hawaiian waters; whether these come from the
same equatorial stock as the eastern Pacific skipjack is not
known. There is some direct avidence that the two fisheries
are related: two skipjack tagged off Baja California in 1960
were caught in the Hawaiian fishery about 2 years later.
Another skipjack from Baja California was caught at
Christmas Island 16 months after tagging.

Other .scientists have suggested that the skipjack of the
eastern Pacific make long offshore-inshore migrations. What
is new about Rothschild's hypotheses is that dimensions
have now been postulated for these migrations: they reach
from the coasts of the Americas 3,000 miles westward to
the equatorial waters south of the Hawaiian Islands. New
is the suggestion that the Hawaiian and eastern Pacific
fisheries are to some extent drawing on the .same population,
with the implication that the "season" skipjack on which
the Hawaiian pole-and-line fishery so heavily depends may
be those which have escaped the nets of the eastern Pacific
fishery earlier in their lives (fig. 13).

Rothschild offers evidence of fluctuations in year-class
strength in the skipjack. This means that Hawaii could
well serve as a base from which future eastern Pacific
catches could be forecast as they could not be in the fishery
area itself. The reasoning is this: Some of the skipjack
taken in Hawaii originate in the same Equatorial Zone as do
those caught in the eastern Pacific; the Hawaiian catch
appears to reflect fluctuations in year-class strength : n
knowledge of the mechanisms that affect year — class
strength in the central Pacific would provide a lever toward
understanding success of spawning in the Equatorial Zone
and hence allow estimates of eastern Pacific catches.

Rothschild's paper is particularly important because he
suggests critical tests of the hypotheses advanced. Because
adult skipjack at the time of spawning have so far almost
completely eluded capture, the next best indicators of recent

18

spawning, the larval and juvenile skipjack, should be sought
in an area of the Pacific reaching from the Hawaiian Islands
2.400 miles southeast to the Tuamotu Archipelago, and their
genetic relationships determined. Equally important will be
genetic studies of the skipjack of the eastern Pacific catch.

A few days before Rothschild's paper was scheduled to
come off the press, the Laboratory received a copy of the
Bulletin of the Tolioku Regional Fisheries Research Labora-
tory that contained an article by T. Kawasaki whose conclu-
sions to some degree paralleled those of Rothschild. It is
interesting that two men working independently should have
arrived at somewhat similar conclusions from the sparse
existing data on an exceedingly complex problem.

Kawasaki goes a step further than Rothschild is now
prepared to do. He suggests that there are relations between
the catch in Japan and that in the central Pacific. If he is
right — and it is not known that he is wrong — he has intro-
duced a new element into considerations of the fishery. The
present controversy over the salmon of Bristol Bay illus-
trates vividly some of the difficulties that can arise when
two nations draw upon a single stock. The possibility that
his assumption may be valid underscores the pressing need
for more detailed information about the skipjack resource.

Hawaiians, Californians, and Japanese are not the only
fishers of skipjack tuna. It is one of the most widespread of
the food species. Prior to World War II, the islands that
now form the Trust Territory of the Pacific were mandated
to the Japanese, and a skipjack tuna fishery flourished there,
taking as much as 72.8 million pounds in a single year,
seven times the average Hawaiian catch. Today this fishery
is being revived under the auspices of the i)resent trustee of
the islands, the United States. A substantial fieet is build-
ing up at Palau in the Carolines and an American compan\-

I'K.l l<\: I I. A n<» iirl 2 lili'li'r~ (aboul 6 fi-it) l<> lh«-

>'u\v h;i^ l4-^lf(l ii(T Oahu in ihi- vunimiT of I yfl-S. l! >*«?•

conipar*'*! wilh lh4- rirciilar m-l I mt-lrr in ilianwU'r that i*
Hifl<'l> li^rd lo t-ol)<-f*l iilaiikliin.

19

has established a freezing plant there. In the spring of 1!)65.
with the cooperation of the High Commissioner of the Trust
Territory and the American firm there, the Bureau's Lab-
oratory in Honolulu stationed an observer at Palau to
document the resumption of the fishery at a commercial
level. The data from the Trust Territory should offer an
interesting supplement to those gained from the other U. S.
skipjack fisheries and of Japan.

The Youngest Tunas

Our Laboratory has collected more than 3,000 samples of
larval and juvenile tunas from the Pacific. Walter M.
Matsumoto is identifying these fish and preparing charts
of their distribution. He has also studied the larval phases
of other fishes, recently completing a description of the
larval and juvenile stages of the vvahoo ( AvunthocijbiiiDi
solandri), one of the scombrids closely related to the tunas.

Towards the end of the reporting period, Matsumoto has
been investigating improved methods of collecting juvenile
tunas (fig. 14). Often found near the surface, they have
proved to be the most elusive of fish, escaping capture so
readily that much of the information on them comes not
from nets operated by scientists but from the stomachs of
those more experienced collectors — the larger fish.

About 550 million i)Ounds of skipjack tuna are taken an-
nually in the Pacific Ocean. The resource may be able t(]
withstand a heavier rate of fishing. At present, however.
skipjack remain (e.xcept in Hawaii) a secondary resource.
They are taken in the eastern Pacific along with and as a
supplement to or substitute for the more highly valued
yellowfin. In Japan, skipjack suijplement catches of the
most prized of the tunas, the albacore. the other si)ecies
upon which the Bureau's Laboratory in Honolulu is e-xpenil-
ing a considerable share of its research effort.

The Prized Albacore

Honolulu is one of the most cosmopolitan of .American
cities. Its cuisine reflects its various cultures. The diet

ranges from poi to trench fries to kasha, from taro leaves to
spinach to bak choi. There is a particularly wide varietx
of sea foods, both locally caught and imported. The visitor
to the fresh-fish market finds a profusion of fishes for sale,
from the slender, silvery wahoo to the enameled splendor of
the red and blue and green reef fishes.

Much of the product of the fresh-fish market is supplied
by the Hawaiian longline fishery. Although Honolulu is
located in a region fished successfully by the Japanese long-
iiners, the Hawaiian longline fleet, composed of small vessels.
stays close to shore, rarel\' losing sight of land. Only in
recent years have some of the ships, with the encourage-
ment of our Laboratory, ventured 200 or 300 miles to sea.
where in some seasons they were rewarded by catches four
and five times as great as those taken nearer shore.

Tunas make up the bulk of the Hawaiian longline catch:
bigeye and yellowfin account for more than half. Only a
few albacore are caught (about 8 tons in 1962), but these,
it turns out. are uniquely important to science, for the\'
provide key information on the history and habits of this
valuable species.

Highly regarded as a food fish because of its tiavor.
te.xture, and color, the alljacore is found in all the world's
oceans except the Arctic. The Pacific catch is the world's
largest. In 1963, Japan, fishing in three oceans, took 127,300
tons of albacore. Of these. 77.400 came from the Pacific.
The United States, which has the onl>- other large fishery,
took 30,300 tons in an area that reached from Ba.ja California
to the Pacific Northwest and several hundred miles to sea.

Tagging studies have proved that the United States and
Japanese albacore catches in the North Pacific are related.
Working with data from these studies and the catch. Tamio
Otsu of our Laboi'ator\' has depicted a complex pattern of
migrations. Though nianx' features are still obscure, in broad
terms this investigation showed that the albacore are
siiawned in tropical and subtropical waters, migrate to

20

temperate waters in their second year, and enter the eastern
Pacific catch in large numbers in their third year. Many
cross the Pacific to mingle in the catch off Japan, where
they spend several years ; eventually the older fish perform
another migration, returning to subtropical and tropical
waters to spawn. The albacore is a long-lived fish. It does
not reach sexual maturity until its sixth year. The fish that
migrate to the south are large and old.

The albacore taken in the Hawaiian longline fishery are
unlike those caught anywhere else; they are on the average
considerably larger than those in any other North Pacific
fishery. They have reached record weights (93 pounds is
the largest; albacore caught in the eastern Pacific fishery
average about 14 pounds). These fish seem to represent
the large, old segment of the population that has entered
.subtropical waters to spawn. That the albacore do spawn
near Hawaii has been borne out by other studies. Although
tuna eggs cannot be distinguished by species, many of the
postlarvae can. Identification is especially simple for the
albacore postlarva, which develops a flattened haemal spine
on the first caudal vertebra. This unique characteristic
appears in specimens as short as 2 centimeters, about three-
fourths of an inch. Discovery of these small fish in Hawai-
ian waters has shown that the albacore spawn nearby.

Little Albacore
Very few of the juvenile albacore have been taken
by the scientists' nets. More have been found in the
stomachs of billfishes. During this reporting period, Howard
O. Yoshida has studied juvenile albacore collected from
the stomachs of billfishes from the Honolulu fresh-fish
market. From 3, .348 stomachs collected between June 1962
and December 1964, he took 23 juvenile albacore. (Stomachs
contained far more skipjack — 696 ; these form the basis of
another study.) Most of the billfish, 2,791, were striped
marlin (Makaira audax), which weigh from 10 to 325
jtounds.

By measuring the length of the vertebral column of his
specimens, Yoshida was able to estimate the standard
length of the intact fish. Using these lengths and his
information on the date of the landing of the billfish, he
estimated the growth rate of the very young fish, a matter
upon which very little data exist. His estimate is that the
young albacore grow about 3 centimeters (a little more than
an inch) a month during most of their first year of life
(fig. 15). He was able to estimate the date of spawning,
which appears to begin late in May and to last several
months.

It is only rarely that fish smaller than 40 centimeters
(15.6 inches) enter the albacore fisheries. Hence Yoshida's
work corroborates other information that would place the
North Pacific albacore in subtropical or tropical waters dur-
ing the first year of its life. Where its spawning grounds are
centered and how extensive they are, is unknown. Some

JUNE JULY AUG. SEFT. OCT. NOW DEC. JAN. FEB. MAR.
FIGURE 15. The juvenile albacore grows about 3 cenli-
melers (a little more than an inch) a month in Hawaiian
**alers during ihe fir!st vear of its life.

21

evidence suggests the Hawaiian Lslaiuis may be only on
the eastern fringe of them.

Yoshida's work also hints at varying seasonal and annual
abundances of the juvenile albacore in Hawaiian waters.

O'-

W-

20*s

ao's.-

1954

170*E. 180* 17

TONGA
IS.

MARQUESAS
IS

O" W ISO* IW 130° 1^0' W.

V'

1964

10*-

20*

V

30«S.-

FlJh
IS*

MARQUESAS
IS

•SAMOA IS

TONGA
IS. ;

P%.

^1

170° E. 180' 170° 160° 150' 140» iy)« 1^0* TC

tlCrLRE 16. The iireu fishfd for Iuiiuti bv ^e»!ieU ha!«eH
ill Aiiii'riruii Sniilou has fxpandi'il gr4-atl> >inrf operation!'
lM><;aii ill 19,>l. It iioM r€*arlir> cast of \\\v MariiiH-*a?«
iHlaiul^. The lU^K Laboral<ir% in lli>iioliiJu niailitaill> a lii-lil
station tlitTi*, a> it aUo doc? at Paiaii in llii- 'I'ru^t Ti-rritor.f
f>f the Purifir lKlan(l>. Darker shaitiii^ in the fif;tire« al>o\4'
(ll*|liel> areu> of heu\ie>t eateh.

A New Fishery

The North Pacific albacore fishery is relatively old, dating
back to the turn of the century at least. The albacore fishery
of the South Pacific was established'only 11 years ago. The
most important operations are based in American Samoa,
where one American firm established a cannery in 1954.
another in 1963.

Starting modestly with 7 Japanese tuna boats in 1954.
the fishery grew to a total of about 100 vessels in 1963. In
December 1964, 68 vessels from three nations were operat-
ing; 40 vessels were from Japan. 17 from South Korea. 11
from Taiwan.

The growth of the South Pacific fishery has been a matter
of extreme interest to the Bureau's Laboratory in Honolulu.
Samoa provides a rare opportunity to study the early history
of a considerable commercial fishery. As a result, the
Laboratory, through the cooperation of the Governor of
American Samoa and the American firm there, established
a field station at Pago Pago in 1963. Manned by observers
from our Laboratory, the field station is effective not only
in obtaining biological samples of the catches, but also in
collecting catch and operational data from the vessel opera-
tors who deliver their catches to the canneries. These data
are transmitted to Honolulu, where Otsu is preparing a com-
(H-ehensive report on the Samoan fishery.

The fishery has expanded rapidly. Figure 16 shows the
fishing area in 1954, and in 1964, when the vessels were
fishing in an area from the Equator to as far south as 30 ,
the latitude of mid-Australia, and from slightly east of the
international date line to long. 120 W.. south of San Fran-
cisco. The area covers about 8 million square miles and takes
the vessels as far as 3,000 nautical miles from their base.

The fishermen gear their efforts toward capturing the
])rofitable albacore. The albacore catch increased from about
360 tons in 1954 to 14,900 in 1963, but dropped to 11,700
in 1964. Figure 17 shows the total annual landings of

22

albacore, the total number of fishing trips made each year,
and the average catch per fishing trip. The rather sharp
decline in landings in 1964 appeared to be caused by a
decrease in fishing effort, compounded by the effects of a
decreased average catch per fishing trip.
Cooperative Effort

It is obvious that American and Japanese interests are
linked in both the North Pacific, where the fishing fleets
draw on a common resource, and in the South, where
mutually dependent commercial efforts are involved. Fishery
scientists of neither nation can speak with full authority
on albacore problems without access to all available infor-
mation on the Pacific, and much of it has not been published.

Under these circumstances, the Laboratory in Honolulu
in 1964 entered into an informal agreement with the Nankai
Regional Fisheries Research Laboratory, where much of
the Japanese tuna research is conducted, to cooperate in
studies of the albacore. Tamio Otsu left Honolulu in Sep-
tember and spent the next 6 months at Kochi, Japan. Un-
published data from the North Pacific fishery, some going
back to the years before World War H, were made freely
available to him. In return, our Laboratory has provided
its Japanese sister laboratory data from its cruises, from
the eastern Pacific, and from Samoa. Although this project
was launched before the formal beginning of the Inter-
national Cooperation Year, it is fully in the spirit of that
enterprise.

Otsu returned to Honolulu in March 196.5, bringing with
him transcriptions of the Japanese data to be coded, checked,
and key punched so that they can be analyzed by com-
puters. This work is scheduled to be finished by the
end of 1965. The wealth of information in the data should
l)rovide the basis of many new studies of the prized albacore.

The Hidden Resource

The central Pacific is fished by the Hawaiian fleet and
the Japanese. The Hawaiian fleet is rarely out of sight of

land. It takes about 7,000 tons of tuna a year. The Japanesi>
fleet ignores the islands to reap a harvest overwhelmingly
larger than that taken by the Hawaiians.

Several lines of evidence suggest that the Japanese fleet
is not exhausting the protein riches of the central Pacific:
there are still far less potentially harvestable fish caught
than uncaught. The most plentiful tuna larvae in the area
are tho.se of the skipjack tuna. Because the skipjack appar-
ently spawn no more frequently or plentifully than the other
tunas, the presence of these larvae point to the existence in
the central Pacific of an immense population essentially un-
touched by the Japanese longline fleet and only sampled by
the Hawaiian vessels. The bigeye and yellowfin tunas taken
on the Japanese longlines are large and old; somewhere in
the area there must be not only more of these fishes but

a

o
a.

35

30

O 25

g5

20

15

10

rTTTT^

V^,

m

1954 1955 1956

1959 1960 1961 1962 1963 1964

FKU RF. 17. (mil 196.'<, ihr hi>lor< of lanHitig> al Annr-
iraii >ani<ia Ha^ i»n»' of ainiohl ^Irad* inrrt-a^f. T**i> fa<*tor*
am>uiil for lh<- sluriip in 1964: fener \f>><'I.. Hi-rt- ri..liiM^
atul lh«' a^rragr oaN-h |»«-r trip H<Tr«'a..rd.

23

also larger populatiuiis of the smaller and youiig-er tish, that
now are not taken at all.

Speaking at the Governor's Conference on Science and
Technology, State of Hawaii, in January 1965, John C. Marr.
BC'F Area Director. Hawaii, said, "It has been estimated
that these resources could yield an annual catch of jjerhaps
200.000 tons. We know that the resources exist, we know
the general — but not the specific — details of their geograph-
ical distribution, we know that they generally occur beneath
the surface, and we suspect that they occur in schools. We
do not know where major concentrations occur, if such
exist, we do not know their depth distribution and how this
may vary, and we do not know certainly that the fish occur
in .schools."

As this report has shown, much of the work of our
Laboratory is shaped toward solving the problems in meas-
uring, locating, and harvesting this great hidden re.source.

Tunas in the Indian Ocean

.■\lthough it covers one-seventh of the globe, until recently
the Indian Ocean has been one of the least explored areas
on earth. Our Laboratory has planned and implemented
that portion of the U. S. contribution to the great Inter-
national Indian Ocean Expedition that is concerned with
fishery biology. Scientists, technicians, and crew members
from the Laboratory participated in .several of the cruises
of the U. S. biological research vessel Anton Bnittti. In the
course of these cruises, our Laboratory collected informa-
tion on the distribution and abundance of tunas; when
examined in conjunction with data from the Japanese tuna
catches there, this information should Ijring a new uiuier-
standing of the food resources of the Indian Ocean, which
is bordered by teeming nations whose need of new supplies
of animal protein is jiressing.

HfTort in the Indian Ocean was devoted to carrying out a
wide north-south survey to determine the distributional

limits of the \arious species and to gather environmental
data.

Richard S. Shomura, who is analyzing the information
on the high-sea resources of the Indian Ocean, found a most
distinct separation of water types along the transect at
long. 70 E. (fig. 18). Arabian Sea Water with high temper-
atures and high salinities in the surface layers extended
south to about lat. 10" N. In the central Indian Ocean,
equatorial water was found from lat. 10' N. to about lat.
11 S. From there to lat. 37- S., the southernmost station.
South Indian Ocean Central Water prevailed. The other
three transects showed more complex relations.

All of the catches of albacore tuna were made south of
lat. 8 S. in waters that seem to be of the South Indian
Ocean Central type. The albacore were mostly large.

The yellowfin tuna were taken widely in the central and
western Indian Ocean. In the central portion, they were
taken from'about lat. 10 N. to about lat. .30 S. They ap-
peared to be associated with both the equatorial water and
South Indian Ocean Central Water. They averaged 76
pounds.

Bigeye tuna were caught from lat. 10 N. to the southern-
most station, but a gap appeared to exist between lat. 12 S.
and 40 S. They averaged 100 pounds.

The data from the Indian Ocean cruises will be added to
the tremendous store from the Japanese fisheries in a co-
operative study that will be carried out with scientists from
the Nankai Regional Fisheries Research Laboratory. The
study will examine the relation of distribution and abun-
dance to oceanograi)hic features.

One of the aims of the biological program in the Indian
Ocean was to gather information on creatures of the sea
other than food fishes. Included were the zooplankton — those
little drifting marine animals that make up much of the
food of fishes. These data are still being studied. From the
[ireliminary studies have come some interesting results.

24

Bulking large in the economy of the sea and the food
chains of most oceanic fishes are the copepods, small animals
much less than an inch long that resemble shrimp. Biologist
E. C. Jones of our Laboratory has found that in the central
Pacific the occurrence of some members of the copepod
family Candaciidae provides clues to the history of the
waters in which they are collected.

Preliminary results suggest that members of the same
copepod family can be used in the Indian Ocean in the same
way — that certain species are associated with waters of
certain temperature and salinity. The distribution of some
is associated with water found primarily in the Arabian Sea.
that of others with equatorial water or the South Indian
Ocean Central Water.

In another Indian Ocean study, biologist Thomas S. Hida
has examined the fishes collected by bottom-trawling in the
Bay of Bengal and the Arabian Sea and is making a study
of the polynemids (threadfins) of the Bay of Bengal. Some
species of this group are commonly used for food.

Infernational Studies

As has been pointed out, the skipjack tuna populations
of the eastern Pacific, the Hawaiian area, and Japan may
well be linked; certainly Japan and the United States are
drawing on a common albacore resource in the North Pacific :
they are competing, most unequally, for the fishes of the
central Pacific; in the Indian Ocean, Japan takes many more
tons of tunas than does India. Fishery problems, when they
deal with the creatures of the high seas, are not local. They
are at least oceanwide in scale.

FIGIIRE 18. Water tvpes along long. 70° E. transect in
the Indian Ocean, based on teniperulure-salinitv distribu-
tion. Arabian Sea Water is verv Harm, highlv saline. Equa-
torial water is cooler and les> saline. The waters of the
si>uth central Indian Ocean partake 4»f some of the charac-
teristics of both the others.

o
&

H

H

fe

H
N

30

J

'-•;^~~~\ "'••■:.

< — -v..

\ v--.. v^\

\ \ ■••••••.. "^ \

^ ^ \ : ••

/\ N * .•• < .'

/ ^v\ * -• "^ -

25

/ ^

k I ..•••■

^

*v ^

.•

^^^//

K "X ''^

NA^ /

' \l <^ \ '

/ nl <. \ /

20

/ ^ '■■\^ t '

■ "^ : ' \ oJ

/ if •/ 1 u

:

! ^ } I

;

^ 1 h

.*

\<!lsii

\oii/o !

15

wJ^

lOV^/

H^/

\/^/ :

l/ /^

aVi \ 1

/•^/ 1 • •

10

/O/ \': 1

/ 1/ ^

it '

/ 1 i

IK ^

1 1 'i ■

1 1 '/ ••'

/ ll :

\ :' •

5

1 > .7 !

I X 1 ^

34. (

35.0 36.(

SALINITY %o

37.0

25

The Pacific and Indian Oceans provide about one-half of
the world fish catch, although together they constitute
three-fourths of the oceanic waters in the world. Their
shores are bordered by some of the most populous nations
on earth. In these coastal areas alone live about a billion
people, one-third of the world's population.

To develop and properly use the living aquatic resources
of the Indo-Pacific area and further to attain these ends
through international cooperation, an Indo-Pacific Fisheries
Council was established in 1948 under the auspices of the
United Nations. The Council has 17 members, comprising
most of the nations of the region with the notable exceptions
of mainland China and the U.S.S.R. The Council has met 11
times, most recently in October 1964 at Kuala Lumpur,
Malaysia. There the United States was represented by
John C. Marr, Area Director, BCF, Hawaii.

The 12th Session of the Council is now scheduled for
Honolulu in October 1966. It will mark the first time the
group has met on American soil.

One of the most productive fishery regions on earth is the
Kuroshio Current off Japan. Originating in tropical waters,
the warm "Black Current" sweeps northeastward oflT the
coast of Japan, follows a great arc beneath the Aleutian
Islands, and eventually contributes to the sluggish south-
moving California Current that influences the climate of
our western States.

A major international survey of this Pacific counterpart
of the Gulf Stream is now underway. Participating nations

include: Japan, Hong Kong. Korea, the Philippines, the
Republic of China, the United States, and the U.S.S.R. At
the request of the Department of State, Marr serves as
U. S. National Coordinator of the Cooperative Study of the
Kuroshio and Adjacent Regions (CSK).

Object of the CSK is an intensive effort to understand
the oceanography, and secondarily, the fisheries of this
fruitful region of the sea.

The need for international studies of fishery resources,
and particularly tuna resources, figured in the deliberations
of the American Fisheries Advisory Committee when it met
in Honolulu in January 1964. The Committee placed special
emphasis on the fishery resources of Hawaii and the central
Pacific Ocean. Organized under the Saltonstall-Kennedy Act
of 1954, the Committee is responsible for advising the
Secretary of the Interior on general fishery matters. One
of the earliest conclusions reached at the meeting was that
in view of the fact that the tuna fisheries are becoming
more international in nature and world tuna consumption
has increased, the "United States must make every effort
to increase its catch of tuna."

In its proceedings the Committee emphasized the need
for further studies of the oceanography of the Pacific Ocean
as it relates to the fisheries, and it is in that field that for
several years our Laboratory has poured much of its effort,
becoming the acknowledged center of oceanographic re-
search in the central Pacific.

THE SEA

The Cruises of the Townsend Cromwell

Townsend Cromwell was a modest, cheerful, and able
oceanographer who lost his life in a plane crash in 1958.
He was 36. Bearing his name today are a son, a major
ocean current, and one of the Nation's finest vessels for

oceanographic research, a ship much better equipped than
any Townsend Cromwell ever had a chance to use.

The subsurface C'ronnvell Current which Tow^^send Crom-
well discovered while on the staff of the Bureau's Labora-
tory in Honolulu, is one of the principal features of the

26

Pacific Ocean. Shallow and swift, it runs eastward beneath
the Equator for about 5,000 miles, carrying as much water
as 10,000 Mississippi rivers.

The ship, Toinisend Cromwell, especially designed for
oceanographic and fishery research, was commissioned in
.January 1964. By July 1965, she had made 17 oceano-
graphic cruises. A vessel 158 feet long, she has a cruising
speed of 12.5 knots and can carry 10 scientists and 15
officers and crew. She can travel anywhere in the Pacific.
Her equipment includes radar, Loran, echo sounders, record-
ing pyranometer, and such new and specialized scientific in-
struments as a salinity-temperature-depth recorder.

In February 1964 the newly commissioned vessel sailed
from Honolulu on a 20-day oceanographic cruise that took
her 960 miles south, 550 miles east, and 240 miles north of
Oahu. For the next 16 months, except in August 1964, she
set forth on a voyage that followed the same unaltering
course. When the last cruise of the series was completed on
July 2, 1965, she had sailed 72,000 miles, spent 320 days at
sea, collected many thousands of items of data, and proved
a significant point : that the work had been well worth
doing.

The waters of the Hawaiian region rank among the most
intensively studied in the world. More oceanographic cruises
have put forth from Hawaii than any of the other 49
states, except California and Massachusetts (the sites of
the Nation's largest and oldest oceanographic institutions)
and perhaps Washington. The Hawaiian waters are so well
known, in fact, that oceanographers are now in a position
to progress beyond a broad, essentially static description of
average conditions in seasonal and annual terms to analyses
of the dynamic processes these conditions refiect. This dif-
ference is approximately that between a still photograph
and a motion picture. It was the Townsend Cromwell's
mission to gather the sequential data on which such studies
must be based, and to survey the distribution of physical

and chemical properties of the ocean with area, depth, and
time.

Although the numbers and distribution of fish must be
intimately related to changes in the environment, not until
a few decades ago did scientists feel confident enough of
their knowledge of the fisheries and the ocean to begin
attempts to link the two. But with the prodigious growth
of oceanography and fishery biology during the past few
years, such efforts have been made in several fisheries
located in many areas of the world ocean. In Japan, for
example, oceanographers have used their investigations to
locate promising areas for the tuna fleet. As another in-
stance, our Laboratory in the 1950's found rich accumula-
tions of tuna in the equatorial region south of the Hawaiian
Islands. The Towimend Cromwell's cruises were undertaken
in support of an enterprise of somewhat more sophistica-
tion than these pioneering ventures ; they were part of an
effort to depict the whole environment as it changes through
the year.

The central Pacific affords a particularly convenient
laboratory for such investigations. As has been said, sea-
sonal and annual conditions in the surface waters are well
known. The climate is equable, so that field studies can be
carried on throughout the year and thus comprehensive
winter data, so rare in studies of the temperate Pacific, can
be readily obtained. The pronounced seasonality and sharp
annual fluctuations in the Hawaiian skipjack catch suggest
that if the availability of the fish directly reflects changes
in their immediate environment, then that availability can
be readily monitored from catch statistics. And the partial
success of the "aku forecasts" hints that skipjack avail-
ability is related to observable dynamic processes in the
ocean.

The Hawaiian Oceanographic Climate
In 1962, after analysis of all the data available at that
time, oceanographer Gunter R. Seckel of our Laboratory

27

30«
N.

20«

10«

■fw"^r^ww^ww^ww^^w»r^wwww*w!?ww^

NORTH PACIFIC CENTRAL WATER

HAWAII »

_\V^V

NORTH PACIFIC EQUATORIAL WATER

■■'^^^^i^s^issMS^^SMmim..

%s^$v^\'SSS$^i$iS-JiS$SJ^i;sx-;;'

170" W.

150"

140"

130»

120"

published a description of the oceanographic climate of the
Hawaiian region. Describing the mixed layer, that warm
upper skin of the ocean that extends from the surface to
the thermocline a few score feet below and which is charac-
terized by temperature and salinity values that change only
negligibly with depth, he found that the central Pacific can
be thought of as two adjacent lakes whose waters have
differing properties. The banks of these lakes are not solid

earth but those immensely wide streams in the ocean we
call currents. The.se currents follow irregular, meander-
ing courses in time and space, now squeezing an adjacent
lake, now allowing it room to expand. And the currents
themselves contract and dilate with the different seasonal
wind regimes.

Tlie current in the central Pacific, which is called the
California Current Extension, generally runs south of the

28

FlGliRE 19. In winter and fall, the Hawaiian I^land^ are
usually bathed by the highly saline waters of the North
Pacific (Central type, in summer their shores are washed
hv less saline waters from the California (Current Extension.

Hawaiian Islands in the fall and winter and shifts northward
to bathe the archipelago in the spring and summer. It
separates the highly saline water of the North Pacific
Central water type on the northwest from the less saline
water of the North Pacific Equatorial water type on the
southeast (fig. 19). To interpret seasonal changes in the
positions of these three bodies of water, Seckel formulated
a simplified heat budget for the region. This budget indi-
cated that warm water was flowing into the region during
the early spring, and cold water at times in other seasons.
Thus sea surface temperatures responded not only to the
amount of solar radiation in the region itself, but reflected
processes that had their origin far out in the Pacific. The
sea surface temperatures, however, described massive water
movements far less clearly than did salinity values. Because
the Hawaiian region is neither one of extreme evaporation
nor precipitation, surface salinity is less affected by seasonal
changes than is surface temperature, which is primarily
responsive to the seasonal march of the sun. For this rea-
son, the movement of isohalines, lines of equal salinity value,
within the region can be interpreted to depict the movement
of the boundaries of the water types in the area. He found
that these movements could be predicted to some degree
from temperature and salinity data gathered twice weekly
at Koko Head, Oahu, Hawaii.

The movements of the upper layers of the water are
largely determined by the winds, and the dominant wind
system of the lower latitudes of the North Pacific is that of
the trade winds. On the basis of the studies briefly sum-
marized above, Seckel proposed that the Bureau's Laboratory
in Honolulu begin a long-term investigation of the oceano-
graphy of the Trade Wind Zone, an area larger than the

continental United States and reaching from long. 135° W.
to 180% and from lat. 10" N. to 30" N. (fig. 20). The proposal
called for a three-phase study: design and planning, field
work, and evaluation of the results.

When the Toioisend Cromwell sailed on the June 1965
cruise, she was concluding the initial part of the first phase,
which has been called the Trade Wind Zone Oceanography
Pilot Study. Although about twice the size of Texas, the
area covered by the Townsend Cromwell in the Pilot Study
is small in comparison with the entire Trade Wind Zone
(fig. 21). It is only as large as one ship, even as swift and
well-equipped for scientific work as the Townsend Cromwell,
can cover in a single month. The pattern for the scientific
observations (fig. 22) was established early in the series
of cruises and did not vary significantly throughout. This
unchanging routine, in fact, was the heart of the study,
whose object was to document month-to-month changes in
the oceanographic and meteorological properties in the area,
with the ultimate aim of understanding the relation of winds
and weather to the oceanographic properties at the surface
and to a depth of more than a quarter of a mile, particularly
as they affect the commercial fisheries.

The plan for the investigations included 43 oceanographic
stations 90 miles apart. Samples were obtained at 20 levels
to about 4,500 feet. After July 1964, casts to about 12,000
feet were made on three stations each cruise. Bathythermo-
graphs, which record temperature in the upper layers of the
ocean, were taken at 30-mile intervals along the cruise tracks,
except at three locations on each cruise, where they were
made at 10-mile intervals. In addition, meteorological obser-
vations were made and the radiation from sun and sky was
recorded.

Seven persons are now engaged full time in processing
the data gathered on the cruises. The data are being trans-
ferred to cards for analysis by computers at the University
of Hawaii. The data are scheduled to be published in 1966.

29

They will be followed by a series of descriptive and analy-
tical reports in 1966 and 1967. Preliminary analyses have
shown that the monthly cruises have gathered information
that does indeed provide new insights into processes in the
ocean.

Beneath The Surface

Man lives in a sea of air, the most immediately perceptible

characteristics of which are temperature — is it hot or cold?

— and humidity — is it wet or dry? Taken together, these

properties define climate. Neither alone will do so. In July

30

KIGIIRE 20. Trade W ind Zone of the North Pacific Ocean.
< )rean<»praph> of the zone is to be in\esti{jateil by ih*' B('F
l.:thiiral«ir« in Honolulu.

the weather i.s equally warm in New Orleans and Tucson, but
a man who flies from the one city to the other will have no
difficulty in distinguishing between the languorous breath
of the South and the crisp air of the West. Conversely, the
air in w-arm Miami in summer can be as humid as that in
cool San Francisco.

The creatures of the ocean live in an environment whose
climate and weather can likewise be described to some
degree in terms of two properties — temperature and salinity.
Is it hot or cold? Is it very saline or less so?

Neither temperature nor salinity values vary widely in
the central Pacific, but these variations might define oceanog-
ra[)hic climates as distinguishable as those of New Orleans
and Tucson, Miami and San Francisco. And variations exist
not only at the surface, but beneath it, so that a man might
lish at the same depth in the same spot in two successive
months but be taking his catch from waters of sharply
contrasting climates.

The detailed description of the subsurface layers of the
ocean in the Hawaiian region is one of the fruits of the
Trade Wind Zone Oceanography Pilot Study. As a result of
their preliminary analyses, Seckel and his colleague, Robert
L. Charnell, are able to say that south of the Hawaiian
Islands are locations where the upper 300 meters (about
1,000 feet) contain as many as four distinguishable layers
of water whose salinity values suggest they originated in
surface water types formed many miles away (figs. 23 and
24). This finding emphasizes the importance of the Hawaiian
region as a monitoring station, for here in one easily acces-
sible location are reflected the effects of energy input in the
Pacific wind systems from lat. 40" S. to above 40° N.

145"

FIGURE 21. In the I'ih.l .Slud> for the Trad. \» in.l Zone
investigation, thi- Tawnnrnd t-roniicell rovere*! the tr;i(-k
shoMii al>o\e each month f<»r 16 months.

31

These layers of water change in size and position, and
sometimes most rapidly; along a meridian, displacements by
as much as 300 miles in a month have been observed. The
movement of each of the various layers appears independent,
yet the distribution of properties is dependent upon occur-
rences in each of the layers.

These initial results of the Pilot Study support the feasi-
bility of the full-scale investigation. This research will
require the use of three ships over a period of 18 months
to 2 years. It will start in 1967.

Nothing exactly like the Trade Wind Zone Oceanography
investigation, both in nature and scope, has been attempted
before. Although it springs from an interest in fishery
problems and the compelling need to understand better the
relation of the fish to the sea, the study will bear impor-
tantly on the fields of meteorology and naval operations. It
might also provide information that would make this type
of investigation no longer necessary, for it could point to
those sites in the ocean where such observation platforms
as anchored buoys might most appropriately be located, thus
making it possible to obtain truly synoptic data on oceanog-
raphic and meteorological conditions in midocean without
the use of surface ships.

The First Mile Down

In the preceding section it has been shown that to under-
stand the nature of the water column in the vicinity of the

FI(;i'RE 22. The heart of (he Pilot Sludv of the Traile
\^in<i /one waj* an unvarying pattern of observations of
<M-eani>eraphir properties month by month. At the left a
terhnirian reads temperature registered by thermometer
in >ansen boltle. In the center a technician operates the
hnth> thermograph winch. She is Karbara Boldt, the first
ttoman to serve as a sea-going technician at this l.ab<irator> .
Al the right the '*fish*' of the salinity-temperaturcHlepth
recorder is brought aboard the Townnend i'.roinwoH.

32

-«j<8«;>

'■ ♦-."w

33

^B r^ORTH PACIFIC CENTRAL VMTER | | CALIFORNIA CURHENT EXT.

L . I :;oRTH rm:ific equatorial water ^^ north pacific current

10* N.

latitude

Hawaiian Islands, one must take into account the climate
and weather of areas thousands of miles away. The face of
the earth is essentially a single ocean interrupted by islands
that range in size from a single lonely volcanic peak thrust-
ing up from the floor of the deep sea to the vast bulk of
Eurasia. This ocean occupies more than 70 percent of the
surface of the earth. For many reasons, however, the chief

FIGIKE 2:<. Saliiiilv valut-^ along long. 148 \i . in Mav
and Oclobrr 1964. Thr .-rclions rxtrnd to a depth of 500
nielors, about 1,500 frot. The shading delineates bodies of
Hater whose salinities are eharacterisljc of surfaee values
in other parts of the ocean. Note thai at lat. 13° N. there
are four layers of waters of different types in the first SOO
meters (1.000 feet).

being that each occupies an identifiable basin and thus forms
a convenient unit of study, it is conventional to regard this
world ocean as being comprised of four smaller oceans, the
Pacific, the Atlantic, the Indian, and the Arctic. The.se
bodies are still very large entities; the Pacific Ocean alone
occupies about one-third the surface of the earth.

A Pacific-wide Study
Although conditions within one part of the Pacific influ-
ence those in all others to some degree, studies of the Pacific
Ocean in its enormous entirety are relatively rare. At least
two reasons account for this circumstance. The first is that
.some studies can be made in a relatively small region with
acceptable precision even if one neglects the influence of the
remainder of the ocean. The second reason is simply that it
is a tremendous task to study the ocean as a whole. Ocea-
nographic research has been conducted in the world ocean
for almost a century now. An immense fund of information
has been collected, particularly within the past few decades.
Until the development of computers, it was impossible
to handle these data without undue expenditures of money
and time. Today analysis of all temperature and salinity
data now available from the Pacific Ocean by manual
methods would run to some 200 man-years and an expend-
iture of $1.5 million.

FIGURE 24. Surface origin of water types shown in figure
23. By sampling the water column near Hawaii, oceanog.
raphers ran see the results of events that have happeneil
hundreds or even thousands of miles awav.

34

Yet critical fields of study exist in which one does need
to examine the entire Pacific Ocean, or large sections of it.
Some of these fields lie within the range of fishery research.
An example might be the investigation of albacore catches
of the North Pacific. Here is a fishery that reaches from
the shores of North America to those of Japan. If one hopes
to investigate the response of albacore to oceanographic
conditions, one must consider this entire 6,000-mile-wide
sweep of water.

Faced with a problem such as this, the biologist recog-
nizes that he has neither the time nor the professional
competence to analyze the scores of separate .studies of an
area of this extent. What he needs is a single publication
in which all the available information has been evaluated
and summarized by an expert in oceanography.

Adequate publications exist for the surface layer of the
Pacific Ocean and for the layers below about 1,000 meters.
Yet the chances are great that the biologist's primary

130» E. 140° 1150» 160" 170" 180° 170" 160" 150° 140° 130" 120° 110" W.

35

interest will focus on the intervening layers, from those just
below the surface to 1,000 meters, for these hold the world's
substantial stocks of marine creatures, including the tunas.
Existing atlases of this marine domain are based on limited
amounts of data (less than half the total, at the best) and
rest upon methods of analysis relatively insensitive to some
of the subtle changes in oceanographic properties.

Recognizing these needs, Richard A. Barkley of our
Laboratory started 5 years ago to prepare such a publica-
tion. It has now been completed and is ready for submission
to the publishers, so that by 1967, or if all goes well, late
1966, there will be available an atlas of the oceanographic
properties of the top 5,000 to 6,000 feet of the entire Pacific
Ocean, based upon 50,000 oceanographic stations.

The 3 million observations upon which the atlas draws
come from cruises as early as 1906, and as late as December
1964. The data have been supplied on punched cards by
the National Oceanographic Data Center. They have been
analyzed at our Laboratory, by use of the facilities of the
University of Ha'waii Statistical and Computing Center for
most of the automatic data processing.

The atlas emphasizes the density structure of the Pacific.
This structure is closely related to processes of advection,
mixing, and water-mass formation. The atlas contains a
series of 135 charts showing properties along the various
sigma-t (density) surfaces, with the deepest at about 2,000
meters average depth. These charts are arranged by quarter
years. In addition, the atlas contains a set of vertical
sections that extend across the Pacific from Asia to the
Americas, and from about 30° S. to the northern boundaries
of the Pacific. Other charts show temperature, salinity,
and sigma-t at 10 meters by months and the density of
observations at several levels by quarter.

Examples of the charts are shown in figures 25 and 26.
In figure 25 is shown the 25.40 sigma-t surface averaged for
January, February, and March throughout the Pacific. The

lighter lines at the top and bottom of the chart show that
this layer reaches the surface level of the water at mid-
latitudes (it sinks to more than 1,000 feet off Japan). The
surface layer north and south of these lines has water of
higher density. Plotted on the chart are the salinity values,
which also reflect temperature distributions, since density
is a function of temperature and salinity. It is easy to see
on this chart the effect of the large rivers of the Pacific
Northwest as they p)our into the ocean and decrease the
average salinity. Their influence is felt over a good part of
the eastern half of the North Pacific Ocean.

Figure 26 is a vertical section showing average values of
salinity and depth reaching from 30° S. to 53° N., from
Chile to Canada, along long. 139° W., which runs near the
Marquesas Islands. The vertical scale is density, and this
accounts for the irregularity of the top line. As the lower
panel makes apparent, the density of water above 1,000
meters varies c«msiderably ; it is least dense (lightest),
depth for depth, at about 10° N.

The atlas will provide the basis for a number of analytical
studies. Two already underway include work on the three-
dimensional distribution of mass transport by currents and
rates of water-mass formation and dissipation. These and
a variety of other related research projects are intended to
lead towards a realistic conceptual model of the Pacific
Ocean that can be used in computer-simulation experiments
to study such factors as diffusion and biological consumption
of dissolved oxygen, as well as the response of the ocean
currents to changes in the atmosphere. Thus the atlas
will have a bearing on a host of studies in fishery biology,
as well as constituting a definitive document in the oceanog-
raphy of the Pacific.

Drift Cards and Collecting Nets
In addition to the completion of the atlas, which has occu-
pied much of the energies of Barkley and his associates
during the reporting period, two other projects in oceanog-

36

PACIFIC OCEAN

\^r--^. (7,= 2S.40 JAN.- FEB.- MAR.

SALINITY %.

\'-^\\^\\

mtntstt di

100* IKS' 120' ll6° 140^ 1^' iGty " 170° 180° 170° 160° 150°

0° 130' 150° 110° iO(y 90° 80° 70°

FIGURE 25. Chart from the oceanographic atla!^ of the
Pacific Ocean, showing a »ignia-t (density) surface that
extends from iho surface (northern and southern extremes)
to a depth of about 1.000 feel off Japan. The period is
Jaiiuar> through March. The values marked by numbers

are those for salinity, which is given in parts per thousand.
The effect of th*- large rivers of the Pacific Northwest is verv
clear from the salinity distributions. The discharge of fresh
water into the sea is evident for hundreds of miles offshore.

37

30" S. 20'

10' 0" 10'

LATITUDE

50° N.

FIGURE 26. Vertical section showing average values of
salinity and depth from lat. 30' S. to 53^ N. along long,
139 W.

raphy have been conducted. One, now nearing completion,
is a continuation of the .study of surface ocean currents
around the Hawaiian Islands by the use of drift cards. For
a year or more, drift cards have been dropped from an
airplane flying a fixed pattern near the island of Oahu each
month. The results of the drift-card returns are now being
analyzed. The ,second study ventures far afield from physical
oceanography and concerns itself with the mathematics
involved in the problem of trapping the small creatures of
the sea in nets.

Fishermen are not the only persons who deplore the fish
that got away. Scientists are equally concerned. As has
been mentioned, the standard collecting device for plankton
is the 1-meter net. Barkley has published a short paper
with a long title, "The theoretical effectiveness of towed-net
samplers as related to sampler size and to swimming speed
of organi.'^ms," in which he explores the relation of the
mouth opening of the collector, the towing speed, and the
estimated swimming speeds of the animals captured. One
of the interesting things that has come out of the paper
is a set of estimates as to how fast the creatures would
have to swim to escape nets, both standard and uncon-
ventional, towed at various speeds. The data collected by
Walter Matsumoto and mentioned earlier may be of value
in testing the soundness of this theoretical treatment,

A Submarine for Research

On June 17, 1965, Secretary of the Interior Stewart L.
Udall announced that a study sponsored by the Bureau of
Commercial Fisheries shows that it is feasible to build a
specially designed nuclear-powered submarine for fishery
and oceanography research.

The study was conducted by Electric Boat Division of
General Dynamics Corporation, Groton, Conn., the pioneer
submarine designer and builder that developed the Xautiliis,
Skipjack, George Washington, and other submarines.

Much of the preliminary re.search on this project was
conducted at the Honolulu Laboratory by Donald W. Stras-
burg. It has become increasingly apparent to the Laboratory
that neither the tuna resource nor the oceanic environment
can be fully understood on the basis of observations from
surface vessels, A submarine would make a better platform
for tuna research. The known behavior and distribution of
tunas indicated that such a vehicle should have a 20-knot
speed, a 1,000-foot operation depth, and a submerged endur-
ance of 6 weeks. Provisions for direct viewing of fish, con-

38

FIGURE 27. Platttic model of nuclear-powered >ul>niuriiir
proposed by this Laboratory for fisherv-oceanography
research. The craft would be 163.S feel long and carry

a scienliiic party of 7, a crew of 24. It would be able In
make a ho^l of sludie^ impossible t<i carry out from
surface ship>.

39

tinuous environmental sampling, and quiet operation are
also essential.

With these criteria, Electric Boat has made preliminar.v
designs for a submarine (fig. 27) that would be 163.5 feet
long (a few feet longer than the Totnisend CromwtU) , have
a maximum submerged speed of 20 knots, a surface speed
of 11 knots, an operating depth of 1,000 feet. The craft
would carry 7 scientists in addition to the crew of 24. The
vehicle would be unique in almost all respects. There would
be an 8-foot observation sphere in the bow with five windows
for direct observation. The scientific laboratories would
equal or excel those of surface craft. Equipment would
include: water sampler capable of delivering 15 water
samples simultaneously, hull-mounted instruments for
recording temperature, salinity, and depth ; a continuous-
transmission, frequency-modulated sonar; two inverted echo
sounders. Seven television cameras would be mounted on
the hull. In the stern laboratory would be placed a tube

from which trawls, plankton nets, fishing lines, bottom
samplers, and other instruments could be launched while
the craft is submerged.

The object of the submarine is to place the scientist in
the environment which he is studying. With it, he would
be less dependent on weather (most oceanographic opera-
tions are necessarily conducted in equable climes, although
the fish are less radically affected). The submarine could
study such oceanic features as thermoclines, fronts, cur-
rents, turbulence, and waves, where precise control and the
ability to hover or maneuver in three dimensions are needed
to define the features of the environment or determine the
relations among variables. A neutrally buoyant submarine
could accompany a particular water mass and measure its
changing physical and biological properties. There is little,
in fact, in observational oceanography that the submarine
cculd not undertake, and further uses will undoubtedly
present themselves when the craft is available for operation.

REPORTS

January 1, 1964 - June 30, 1965

BARKLEY, RICHARD A.

19(i4. The theoretical effectiveness of towed-net .samplers as

related to sampler size and to swimming speed of organisms.

J. Cons. 29(2) :146-157.
11104. Studies of ocean currents near the Hawaiian Islands.

[Abstract.] Proc. Hawaiian Acad. Sci., 3U Annu. Mtg.,

1963-1964, p. 2.5-26.

BARKLEY, RICHARD A., BERNARD M. ITO, and
ROBERT P. BROWN.
I9(i4. Releases and recoveries of drift bottles and cards in the
central Pacific. U. S. Fish Wildl. Serv., Spec. Sci. Rep. Fish.
492, iii + 31 p.

BROWN, ROBERT P.

19G.5. Delineation of the layer of maximum .salinity in tropical
and subtropical oceans by means of bathythermograph
traces. Limnol. Oceanogr, 10(1 ) :1.')7-16U.

FUJINO, K., and L. M. SPRAGUE.

In press. The Y blood group system of the skipjack tuna
(Kntsiiivonus lielamis). [Abstract.] Genetics.

GOODING, REGINALD M.

1964. Observations of fish from a floating observation raft at sea.
[Abstract.] Proc. Hawaiian Acad. Sci., 39 Annu. Mtg.,
1963-1964, p. 27.

1965. A raft for direct subsurface observation at sea. U. S. Fish
Wildl. Serv.. Spec. Sci. Rep. Fish. 517, iii -f- 5 p.

HIDA, T. S., and W. T. PEREYRA.

In press. Results of bottom trawling in Indian Seas by R/V Anton
Biiitiii in 1963. Tech. Rep. lado-Pac. Fish. Counc.

•Reports listed here were published duriTiK this reporting period or were in press
in June 1965.

40

JONES, EVERET C.

1965. Evidence of isolation between populations of Ciindncia
IKichi/diictyla (Dana) (Copepoda: Calanoidai in the Atlan-
tic and the Indo-Pacific Oceans. [ Ab.stiact.] Symposium on
f'rustac'ia, held under the auspices of the Marine Biological
Association of India at the Oceanographic Laboratory, Uni-
versity of Kerala, Ernakulam, 12-15 Janur.ry l'J65, Abstract
of Papers, p. 18.

1965. The general distribution of species of the calanoid copepod
family Candaciidae in the Indian Ocean with new records.
[Abstract.] Symposium on Crustacea, held under the aus-
pices of the Marine Biological Associ;-tion of India at the
Oceanographic Laboratory. University of Kerala, Ernaku-
lam, 12-15 January 1965, Abstract of Papers, p. 17-18.

KEALA. BETTY ANN L.

1U65. Table of sigma-t with intervals of 0.1 for temperature and
salinity. U. S. Fish Wildl. Serv., Spec. .Sci. Rep. Fish. 506,
186 p.

MAGNUSON, JOHN J.

1U64. Activity patterns of scombrids. [Abstract.] Proc. Hawaiian
Acad. Sci., 39 Annu. Mtg., 1963-1964, p. 26.

1964. Tuna behaviour research programme at Honolulu. /«
Modern Fishing Gear of the World, 2:560-562. Fishing
News (Books) Ltd., London.

In press. Tank facilities for tuna behavior studies. Progr. Fish-
Cult.

MARR, JOHN C.

1965. Oceanographic instrumentation and Hawaiian fisheries.
Proceedings of the Governor's Conference on Science and
Technology, State of Hawaii, January 26-30, 1965, p. 67-72.

In press. Research program of the U. S. Bureau of Commercial
Fisheries Biological Laboratory, Honolulu, Hawaii. Marine
Biological Association of India Symposium on Scombroid
Fishes.

MURCHISON, A. EARL, and JOHN J. MAGNUSON.

In press. Notes on the coloration and behavior of the common
dolphin, Coryphaeiiii hippitriis. Pac.Sci.

NAKAMURA, EUGENE L.

1964. A method of measuring visual acuity of scombrids.
[Abstract.] Proc. Hawaiian Acad. Sci., 39 Annu. Mtg.,
1963-1964, p. 26-27.

1964. Salt well water facilities at the Bureau of Commercial
Fisheries Biological Laboratory, Honolulu. In John R.
Clark and Roberta L. Clark (Eds.), A collection of papers
on sea-water systems for expL-rimental a<iuariums. U. S.
Fish Wildl. Serv., Res. Rep. 63:169-172.

In press. Food and feeding habit.; of skipjack tuna (K'ttsiiivuniit
pelamis) from the Marquesas and Tuamotu Islands. Trans.
Amer. Fish. Soc.

In press. Fiber glass tanks for transferring pelagic fishes. Progr.
Fish-Cult,

NAKAMURA, EUGENE L., and JOHN J. MAGNUSON.

1965. Coloration of the scombrid Euthyiniiis affliiis (Cantor).
Copeia (2) :234-23o.

ROTHSCHILD, BRIAN J.

1964. Observations on dolphins (Coryphaeiii spp.) in the central
Pacific Ocean. Copeia (2):445-447.

1964. Skipjack tuna oceanography. [Abstract.] Proc. Hawaiian
Acad. Sci., 39 Annu. Mtg., 1963-1964, p. 25.

1965. Hypotheses on the origin of e.xploited skipjack tuna (Katsii-
ivotiiis peUiniis) in the eastern and central Pacific Ocean.
U. S. Fish Wildl. Serv., Spec. Sci. Rep. Fi.sh. 512, iii -|- 20 p.

In press. Some uses of statistics in fishery biology. University of
Hawaii, Proceedings of conference on mathematics: Agent
of change.

ROYCE, WILLIAM F.

1964. A morphometric study of yellowfin tuna, Thiiinuis nlbacares
(Bonnaterre). U.S. Fish Wildl. Serv., Fish. Bull. 63:395-
443.

SECKEL, GUNTER R.

1964. Climatic oceanography and its application to the Hawaiian
skipjack fishery. [Abstract.] Proc. Hawaiian Acad. Sci.,
39 Annu. Mtg., 1963-1964. p. 26.

SHERMAN, KENNETH.

1964. Pontellid copepod occurrence in the central South Pacific.
Limnol. Oceanog. 9(4) :476-484.

SHOMURA, RICHARD S.

1964. Effectiveness of tilapia as live bait for skipjack tuna fishing.
Trans. Amer. Fish. Soc. 93 (3) :291-294.

SHOMURA, RICHARD S., and THOMAS S. HIDA.

In press. Stomach contents of a dolphin caught in Hawaiian
waters. J. Mammal.

41

SPRAGUE, LUCIAN M.

196-i. A new look at an old ocean. [Abstract.] Proc. Hawaiian

Acad. Sci., 3!) Annu. Mtg., 1963-1964, p. 25.
nie.'). Fish immunoKenetics research. Science 148(3674) :1252-

1254.
In press. Serum polymorphisms of the skipjack (Katsiiu'oiiKx

pelamis) and the yellowfin (Xeotliiitiniis inacmijtfriis) tunas.

[Abstract.] Genetics.

STRASBURG, DQNALD W.

1964. A possible breakdown in symbiosis between fishes. Copjia

(1) : 228-229.
1964. An aerating device for salt well water. /« John R. Clark
and Roberta L. Clark (Eds.), A collection of papers on
sea-water systems for experimental aquariums. U. S. Fish
Wildl. Serv., Res. Rep. 63:161-167.
1964. Further notes on the identification and biologry of echeneid
fishes. Pac. Sci. 18(1) :51-57.

1964. Postlarval scombroid fishes of the genera Aciiiithncyhuim,
Nealotiis, and Diplospiiiiis from the central Pacific Ocean.
Pac. Sci. 18(2):174-185.

1965. A submarine for research in fisheries and oceanography.
Transactions of the Joint Conference and Exhibit, MTS/
ASLO. Ocean Science and Ocean Engineering 1:568-571.

1965. Description of the larva and familial relationship.^ of the
fish Snyderidia caniiia. Copeia (l):20-24.

UlNITED) SITATES] BUREAU OF COMMERCIAL FISHERIES.
1965. Progress in 1962-1963. U. S. Fish Wildl. Serv., Circ. 206,
31 p.

VAN CAMPEN, WILVAN G.

In press. A bibliography of research on tunas for the years 1954-
1956. Proceedings of the World Scientific Meeting on th;'
Biology of Tunas and Related Species, 2-14 July 1962.

WALDRON, KENNETH D.

1964. Fish schools and bird flocks in the central Pacific Ocean,
1950-61. U. S. Fish Wildl. Serv., Spec. Sci. Rep. Fish.
464, iv + 20 p.

YOSHIDA, HOWARD 0.

In press. New Pacific records of juvenile albacore Thunnux ala-

lidiga (Bonnaterre) from stomach contents. Pac. Sci.
In press. Skipjack tuna spawning in the Marquesas Islands and
Tuamotu Archipelago. U. S. Fish Wildl. Serv., Fish. Bull.
YOSHIDA, HOWARD 0., and EUGENE L. NAKAMURA.

1965. Notes on the schooling behavior, spawning and morphology
of Hawaiian frigate mackerels, Aiuris fhazard and Au-i'is
rochei. Copeia (1):111-114.

42

Hawaii Area

John C. Mark, Director

LuciAN M. Sprague, Deputy Director

ACKNOWLEDGMENTS

Tamotsu Nakata i)repared the drawings and took the
photograph that appears as figure 27 ; Reginald M. Gooding
provided figure 9 ; John J. Magnuson, figure 8 ; and Jerome
S. W. Marr, figures 1, 2, 10, 14, and 22.

Created in 1849, the Department of the Interior~a department of conservation—is concerned with the
management, conservatior, and development of the Nation's water, fish, wildlife, mineral, forest, and park
and recreational resourcts. It also has major responsibilities for Indian and Territorial affairs.

As the Nation's principal conseivation agency, the Department works to assure that nonrenewable
resources are developed and used wisely, that park and recreational resources are conserved for the future,
and that renewable resources make their full contribution to the progress, prosperity, and security of the
United States-now and in the future.

UNITED STATES
DEPARTMENT OF THE INTERIOR

Fli^II AM) WILDLIFE SERVICE

BURE.'VU OF COMMERCUL FISUERIES

WASHINGTON', D.O. 20210

POSTAGE AND FEES PAID
U.S. DEPARTMENT OF THE INTERIOR