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(INTERNATIONAL NORTH PACIFIC fJSHERIEf' COMMISSIONS^

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N MEETING '

UhMtED STATES DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE
BUREAU OF COMMERCIAL FISHERIES
WASHINGTON, D. C.

S

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A jv

n

CIRCULAR 85

UNITED STATES DEPARTMENT OF THE INTERIOR
Fred A. Seaton, Secretary

FISH AND WILDLIFE SERVICE
Amie J. Suomela, Commissioner

BUREAU OF COMMERCIAL FISHERIES
Donald L. McKeman, Director

INTERNATIONAL
NORTH PACIFIC FISHERIES COMMISSION

UNITED STATES SECTION MEETING, MARCH I960

PAPERS

Presented before a Joint Session

of the

Alaska Legislature

Juneau, Alaska

March 4, I960

Circular 85

Washington, D. C.
May I960

UNITED STATES SECTION
INTERNATIONAL NORTH PACIFIC FISHERIES COMMISSION

Commissioners

Milton E, Brooding, Chairnaan
Edward W. Allen
John H, Clawson
Arnie J. Suomela

Advisors

Clinton E. Atkinson
Stuart Blow
Fred C. Cleaver
Reynold A. Fredin
John T. Gharrett
George Y. Harry
William C. Herrington
Walter Kirkness

Donald P. Loker
J. L. McHugh
Donald L. McKernan
William F. Royce
Williann Smoker
William M. Terry
Wo F. Thompson
W, G. Van Campen

Advisory Committee

C. Lj, Anderson
W. C. Arnold
Harold F. Cary
Richard S. Croker
Albert M. Day
Haakon Friele
DeWitt Gilbert
Milton C. James
George Johansen

Robert C. Kallenberg
Harold E. Lokken
Milo Moore
Alfred Owen
T. F. Sandoz
John W. Smith
Peter Tanstad
Lowell Wakefield
James Waugh

11

CONTENTS

Page

The International North Pacific Fisheries Commission

and its work 1

Statement of the United States Section, International
North Pacific Fisheries Commission, by Milton E.
Brooding, Chairman 3

Scientific research by the United States, by J, L.

McHugh 11

Research related to the case for abstention, by R. A,

Fredin • 13

Distribution and racial composition of salmon on the

high seas, by Clinton E, Atkinson 19

Pacific salmon in international waters, by Allan C.

Hartt (presented by William F. Royce) •>•• 25

111

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Members of the United States Section, International North Pacific Fisheries Commission,
with Governor Egan of Alaska, March 3, 1960.

Left to right: Commissioners Edward W. Allen and John H. Clawson, Governor Egan,
Commissioners Milton E. Brooding and Arnie J. Suomela, State Senator Alfred Owen,
a member of the Advisory Committee.

IV

THE INTERNATIONAL NORTH PACIFIC
FISHERIES COMMISSION AND ITS WORK

Among the world's fisheries, those of the North Pacific
Ocean are in many respects unique. Vast and valuable stocks
of salmon spawn in fresh water, often hundreds of nailes
inland, in rivers that intersect thousands of miles of coast-
line, from Alaska to California and from Siberia to the
islands of Japan. The young soon return to the sea and
migrate over thousands of miles of ocean, feeding on rich
oceanic pastures as they grow and develop to maturity.
Tremendous stocks of halibut spend their entire life in the
North Pacific in relatively shallow waters over the conti-
nental shelf, and the scientific research that led to manage-
ment of these fisheries is a classic example of intelligent
utilization of fishery resources.

The basic principle in management of salnaon stocks is to
determine the optimum numbers of fish that must be allowed
to reach the spawning grounds, and to regulate the fishery
so that these numbers, and no more, escape the fishermen's
gear. Obviously, this control becomes nnore precise if regu-
lations can be applied close to the spawning streams, and
this is why the Pacific coastal states severely restrict
salmon fishing on the high seas.

The prospective development of a large high-seas salmon
fishery by foreign interests after World War II, therefore,
threatened to interfere seriously with management of Ameri-
can stocks. Alaskan salmon fisheries were especially vul-
nerable, particularly the large and valuable red salmon
stocks of Bristol Bay, in the Bering Sea, Entry into force of
the International Convention for the High Seas Fisheries of
the North Pacific Ocean between the United States, Canada,
and Japan in 1953 demonstrated the importance that these
three fishing nations placed upon conservation of high- seas
fishery resources, and their recognition of the need for
research and preservation of historic fishing rights.

Growth of the Japanese high-seas fishery has caused
increasing concern in Alaska, and the responsibilities and
activities of the International North Pacific Fisheries Com-
mission with respect to this situation have not always been
clearly understood. Accordingly, Governor Egan of Alaska
issued an invitation to the United States Section of the
Commission to hold its first meeting of I960 in Juneau, so
that the State Legislature and the public would have an
opportunity to understand better the Convention and the
activities that have taken place since it was ratified in 1953,

1

The United States Section promptly accepted the invitation
and nnet in Juneau early in March I960. The Section, with
its Advisory Comnaittee and scientists, nnet with the Natural
Resources Connmittees of the Senate and House on March 3,
and with the entire Legislature on March 4. In the evening
of March 4 an open hearing was held, at which the Section
and Advisors reviewed the Commission's work, heard state-
ments and answered questions. This Circular contains the
text of formal presentations before the Legislature.

Commissioner Brooding (center) addressing the Alaska Legislature.

STATEMENT OF THE UNITED STATES SECTION

INTERNATIONAL NORTH PACIFIC
FISHERIES COMMISSION

Presented by
Milton E. Brooding, Chairman

Mr. Chairman, Members of the Legislature, Ladies and
Gentlemen:

It is a privilege for the United States Section of the
International North Pacific Fisheries Commission to meet
here for the second time. When we received the invitation
from Governor Egan to hold our next meeting here in
Juneau, we immediately took steps to do so. Being here is
a most enjoyable experience and we deeply appreciate the
courteous reception extended us. We have had an opportunity
to become better acquainted with the Alaska viewpoint and
it is our hope that we can impart to you a better under-
standing of the North Pacific Fisheries Convention- -its
problems, and some of the accomplishnaents of the Com-
mission set up to administer its provisions.

It seems quite appropriate, in fact quite necessary, that
this be done, for there can be no question that affairs of the
Internationcil North Pacific Fisheries Commission impinge
more directly upon the public welfare of the people of Alaska
than those of any other of our coastal states, although all
these states have a deep interest in the affairs of this
Commission.

It would be appropriate at this point to introduce my
colleagues on the U. S. Section: Commissioners Edward
W, Allen, Seattle, Secretary of the Commission; John H.
Clawson, Anchorage; and Arnie J. Suomela, Washington,
D. C. We also have with us several members of our Advisory
Committee as well as scientists and other experts from
your own Department of Fish and Game and from the U, S,
Bureau of Commercial Fisheries in Juneau, Seattle, and
Washington, D. C,

In order to understand the origins of the International
North Pacific Fisheries Commission, the treaty under which
we operate, it is desirable to review some of the circvim-
stances of relatively recent history. Prior to World War II,
the interested public of the Pacific coast of the United States
realized that great Japanese high-seas fisheries were ex-
panding into the North Pacific. Their research vessels were
searching towards the Equator and towards the Bering Sea
for stocks of fish of all varieties. We know from the incident
in the Bering Sea in 1937 that the Japanese were searching
then for salmon in the eastern North Pacific. It appears that
only prompt diplomatic action by our Government at that
early date prevented exploitation on the high seas of salmon
stocks of North American origin.

Many of us, in and out of Government, realized that
expansion of fishing by the Japanese after the war, and the
change in control in some of the land areas of the western
North Pacific, would bring about an inevitable conflict of
interest. Some orderly procedure was needed to protect
the interests of the United States, yet not interfere with the
recognized right under international law of a country to
enjoy the freedom of the high seas.

AH of you know sonriething about the International North
Pacific Fisheries Commission. Some of you, I know, under-
stand it quite well. The Convention deals with highly complex
problems, difficiilt and sometimes conflicting international
interests, and relatively new and not widely understood
biological and conservation concepts. I believe it will facili-
tate our discussions if I first attempt to explain why the
Convention was drafted in its present form.

What is the International Convention for

the High Seas Fisheries of the

North Pacific Ocean?

The Convention is an agreement negotiated between the
United States, Canada, and Japan, chiefly concerned with
conservation principles and procedures to promote the
maximium sustainable yield of North Pacific stocks of fish
of "joint interest'*. The Convention runs for a minimum of
ten years from June 1953 and will continue thereafter until
one year after notice of intention to terminate is given by
one of the parties to the Convention.

The principal provisions of the Convention are:

1, It provides for establishment of a North Pacific
Fisheries Commission, composed of three national sections,
each with four members appointed by the governmsnts of
the respective parties to the Convention, It also authorizes
establishment of an Advisory Committee to each national
section, composed of persons well informed on North Pacific
fishery problems,

2, The Convention requires that the appropriate parties
to the Convention will abstain from fishing stocks of fish
which meet specified criteria, as follows:

a, the stocks are being fully utilized, so that more
intensive fishing will not provide a substantial increase in
yield which can be sustained;

b, fishing is controlled by legal measures in ac-
cordance with conservation programs based on scientific
research; and

c, the stocks are under extensive scientific study
designed to discover whether they are being fully utilized
and to determine the conditions necessary to obtain maximum
sustainable yield,

3, The Annex to the Convention specifies certain stocks
of fish, which, at the tinne the Convention was negotiated,
were found to satisfy these criteria for abstention,

4, It requires the Commission to study the stocks of fish
specified in the Annex to determine whether they continue to
qualify,

5, It provides that on request by any of the three coun-
tries, the Commission shall study any other stock offish
in the North Pacific to determine whether it qualifies for
abstention,

6, It provides that the countries fishing the stocks from
which certain other countries agree to abstain shall continue
to carry out necessary conservation measures for these
stocks,

7, It provides that, on request of any of the three gov-
ernments, the Commission shall study any other fish stock
under substantial exploitation by two or more countries to
determine the need for joint conservation measures,

8, The Convention provides that, if nationals or vessels
of a country not a party to the Convention adversely affect
the operations of the Commission, on request of any of the
three countries which are parties to the Convention, all the
contracting governments will confer to determine steps
necessary to obviate these adverse effects,

9, It spells out provisions for enforcing the Convention
and the various rules under which the Commission shall
operate,

10, The Protocol to the Convention specifies a provi-
sional line, east of which the Japanese will not fish anywhere
for salmon, and east of which the Canadians will not fish in
the Bering Sea for salmon. It further provides that the
Commission shall expeditiously investigate the area to
determine whether there are areas where stocks of salmon

of North American origin intermingle with stocks of Asian
origin. If such areas are found, then the Commission shall
determine a line or lines which best divide salmon of Asian
and North American origins and whether such line or lines
more equitably divide such salmon than the provisional lines
specified in the Protocol.

At the time the Convention was negotiated, the United
States had little factual knowledge on high- seas naigrations
and distribution of salmon. It was generally believed that
salmon spent their marine existence in waters, overlying
the continental shelf. This scarcity of information made
agreement on the location of a line defining the eastern limit
of Japanese salmon fishing very difficult. At one point the
conference caime very close to breakdown because views
regarding location of such a line were widely different.
The Protocol represents a compromise which saved the
conference from failure. At the time the compromise was
agreed upon, we had no information concerning the extensive
intermingling of Asian and North American salmon. It was
thought that if any movement of North American salmon
across the provisional line did occur, it was not substantial.
Our present knowledge is derived entirely from the Com-
mission*s research program of the last few years.

Why was the Convention Drafted
in Its Present Form ?

I believe almost any of us could propose changes in the
Convention which wovild make it much more to our liking.
In fact, I have heard or read many proposals for such
changes from sincere and well-intentioned people. Some of
these proposals appear so reasonable and simple that the
proposer finds it difficult to understand why they were not
included in the first place and, failing that, why they should
not be adopted now. Perhaps I can help to make clear why
this is not so simple as it looks. These are some of the
considerations:

1. Agreements between sovereign powers are based on
mutual interests and persuasion, not dictation. A country's
representatives sign and ratify a treaty only when they
consider that it is in their country's interest to do so,

2. In endeavoring to give protection to our North Pacific
fisheries, it was necessary to reconcile our claim to special
interest in these fisheries with the general international
legal concept of freedom of the seas. To meet the special
situation prevailing in this area, the principle known as
abstention avoided any assertion of ownership or jurisdiction
over any area of the high seas, at the same time that it did
assert that nationals of other countries should abstain from
catching these special stocks which came within the scope
of the principle.

Our salmon and halibut fisheries were developed exclu-
sively by our own and Canadian fishermen. Huge sums were

invested in research and regiilation of these stocks, and we
had reason to believe they were being fully utilized; that is,
additional fishing by other nations would not increase total
production, but would simply replace present fishermen and
discourage continuation of extensive conservation programs
necessary for obtaining the maximum sustainable yield from
these stocks. It was the incentive of increased and sustained
production for their benefit which persuaded our fishermen
to submit to the rigid regulation essential to effective con-
servation of these fisheries. Thus, the principle of abstention
was necessary as a companion measure to the general prin-
ciple of freedom of the seas, in order to preserve valuable
fishery resources that we were maintaining at great effort,

3. We must bear in mind that Japan is a great fishing
nation whose fishing activities are heavily dependent on the
principle of freedom of fishing. Consequently, Japan cannot
support or accept principles or procedures which seriously
endanger this freedom. To minimize Japanese sensitivity to
this problem, our proposals had to be related closely to the
characteristics of the fisheries which I have referred to
above and make clear the unique conservation considerations
and scientific requirements involved,

4, When studying the Convention wording, all of these
points should be kept in mind. The Convention refers to
stocks of fish, and therefore does not involve areas of
jurisdiction* It specifies full utilization, naanagement meas-
ures in accordance with conservation programs, and the basic
requirement that all must be supported by reasonable
conclusions derived from scientific findings.

I will readily agree that the Convention is not in the
precise form, or perhaps even in the approximate form,
in which you or I would wish to draft it if we had complete
freedom to do so, for it includes compromises necessary
for agreement. However, if you will study it closely, I think
you will find that it covers those stocks of fish of primary
interest to Alaska, There is one major exception, the stock
of Bristol Bay red salmon, which we now know migrate far
to the west to areas much closer to the Asian mainland than
to the mainland of Alaska, The results of recent research
have demonstrated that red salmon from Bristol Bay mingle
over a wide area with salmon of Asian origin. The problem
that develops from this is extraordinarily complex, a com-
plexity that derives from the extent and areas of migration,
extensive intermingling, and world politics.

Problems and Accomplishments
of the Commission

We have reviewed the nature and origins of the North
Pacific Convention and the make-up and terms of reference
of the Commission appointed under its provisions. What
are the problems of this Commission and what has it accom-
plished?

The Commission operates under the terms of reference
provided by the Convention. It has no authority to make
decisions or recommendations except as provided by the
Convention's terms. This frame of reference cannot be
changed by the Commission but only by agreement among
the three countries party to the Convention. The United
States Section, as part of the Commission, cannot change
the basic rviles under which it works. It must rely upon the
establishment of a solid scientific basis for the principles
under which the Convention was negotiated.

Operating in this manner, the Commission, and the United
States Section, have been engaged in a number of research
programs which have yielded extremely valuable results.
One of the most important, of course, is the program of
research relating to abstention. Unless the applicability of
the abstention requirement can be demonstrated clearly by
scientific research, the whole basis for the principle is
jeopardized, and abstention as a method of fishery manage-
ment cannot survive,

A review of the principal research projects will be
undertaken in greater detail later. However, it may be
useful at this time to summarize what the United States
Section has been doing in this regard. First, with respect to
salmon and halibut, the analysis carried out by United States
scientists has added substantially to our knowledge and has
greatly strengthened out abstention case in the Commission.
We feel that we have made a strong case for our salmon and
halibut stocks. Work in this field continues in order that
our case regarding all requirements for abstention with
respect to these stocks may be clearly demonstrated.

An extensive analysis of the data on herring stocks has
clearly shown a decrease in the utilization of herring in
recent years. It has shown further that increased fishing
would resiolt in a substantial and sustainable increase in
yield. Since the herring stocks of Alaska thus fail to meet
one of the primary requirements for abstention; i. e,, full
utilization, the United States Section and the Commission
had no choice but to recommend that they be removed from
the abstention list. A failure so to act would have undermined
the whole basis of the abstention principle.

Another important line of research is providing a basis
for interpretation of the Protocol to the Convention and the
question of possible relocation of the provisional line for
abstention by other countries from fishing American salmon.
The Protocol requires the Commission to investigate the
distribution of salmon of North American and Asian origin
to determine the area and extent of intermingling. Acting
under this requirement, the Commission, and particularly
the United States Section, has sponsored the nriost intensive
and extensive high- seas fishery research program ever
conducted.

This program has developed a surprising picture of the
distribution of salmon. They are found in large numbers
ranging completely across the ocean from North America

8

to Asia, New and ingenious methods to determine the origin
of salmon caught on the high seas have been devised.

With these new methods it has been found that Asian red,
chum, and pink salmon, especially chums and pinks, come
almost as far east as the tip of the Alaska Peninsula, Con-
versely, American salmon are found far to sea, moving
thousands of miles during their ocean life. Some Bristol
Bay red salmon are found far west in waters near Kamchatka,

The general outlines of the areas and extent of inter-
mingling have been determined. However, variations in
numbers of the various species in various parts of the ocean
and at various seasons require more investigation.

The Protocol provides that the question of possible relo-
cation of the provisional abstention line shall be referred to
a neutral committee of scientists if the Commission fails
within a reasonable time to make a unanimous recommenda-
tion. At present, however, there is disagreement within the
Commission as to interpretation of certain language of the
Protocol, specifically as to whether the words "best divide**
and "equitably divide*' mean "divide*' in the sense of **to
separate" or in the sense of "to apportion*'.

It is the Japanese contention that the line should divide
the salmon of the area, including all species, in such a
way that the nximber of North American salmon found west
of the line is equal to the niimber of Asian salmon found east
of the line. This would, of course, permit them to catch the
large numbers of Bristol Bay reds which cross the line and
would not interfere seriously with their ability to catch
salmon of Asian origin which move east of the line, for
these salmon eventually must return to Asian shores to
spawn, ivloreover, Asian salmon wovild not be vulnerable
to capture by American fishermen east of the line, for we
prohibit salmon fishing with nets on the high seas.

It is the contention of the United States Section that the
Protocol shoiild be interpreted in the light of the primary
objective of the treaty, which is to apply the principle of
abstention to the entire stock of salnnon coming within its
purview, and therefore the line should be so located that the
Japanese will abstain from catching American salmon. We
recognize, of course, that the abstention principle should
not be interpreted so rigidly that Japan will be prevented
from continuing her historical fishery for Asian salnnon.

Despite the increasing volume of scientific knowledge on
intermingling of North Amierican and Asian salmon, it will
not be possible to refer the data to a neutral committee for
decision until the disagreement over interpretation is re-
solved. The meaning of the language is fundamentcd to the
decision a neutral committee would be asked to make.
Because this disagreement involves the basic terms of
reference of the Commission, the question of interpretation
of the Protocol has been referred to the three Governments
for clarification.

Thus, the Commission is not in a position at present to
come to a decision regarding relocation of the abstention

line. Nevertheless, the scientific work which has been done
and which continues on this subject has yielded substantial
benefits. Can anyone doubt that the facts which have been
brought to light have had a very considerable effect in the
past two years on Japanese high- seas operations west of the
provisional line? Furthermore, we are in a position to
proceed on what we consider to be a basis of solid scientific
knowledge once interpretation of the Protocol is settled.

To sum up, few international agreements which involve
conflicting national interests are perfect documents in the
sense of giving complete satisfaction to all parties. The
North Pacific Fisheries Convention is no exception. The
Convention has not afforded complete protection to ail stocks
of interest to Alaskan fishermen, for Bristol Bay reds are
not adequately covered. However, the Convention has pro-
vided practically full protection for all other salmon stocks
of Alaska and the rest of the Pacific coast and for halibut
as well.

10

SCIENTIFIC RESEARCH BY THE UNITED STATES

by Dr. J. L. McHugh

Chief, Division of Biological Research

Bureau of Commercial Fisheries

Washington, D. C.

Research conducted by the Bureau of Commercial Fish-
eries for the Commission has two major purposes, to provide
scientific knowledge necessary to determine whether the
stocks of fish specified in the Annex to the Convention
qualify for abstention, and to study the distribution of ssdmon
on the high seas to provide knowledge required for proper
interpretation of the provisions of the Protocol. The first
objective, you will remember, is to show: (1) whether or
not more intensive exploitation of the stocks of salmon,
halibut, and herring will yield substantial increases in yield
that can be sustained year after year; (2) that this exploita-
tion is regulated by legal measures to maintain or increase
the maximum sustained yield in accordance with scientific
knowledge; and (3) that extensive scientific study is in prog-
ress to discover whether the stocks are being fully utilized
and determine the conditions necessary to maintain maxi-
mum sustained yields. The second objective is to determine
if there are areas in which salmon of North American and
Asian origin intermingle, and if so, to determine a line or
lines which best divide salmon frora these two sources, and
to show beyond reasonable doubt that this line or lines nnore
equitably divide such salmon than the present provisional
line at 175° West longitude.

Information bearing on the abstention question has been
provided by several agencies. We have received, and are
pleased to acknowledge, the assistance of the Alaska De-
partment of Fish and Ganae on many occasions. The rela-
tionship between numbers of spawners and the success of
fishing when their progeny return from the ocean has been
determined from information provided by the scientific staff
of Bureau of Commercial Fisheries Region 5, based in
Juneau. The staffs of the International Pacific Halibut and
Salmon Commissions have given us nauch useful information,
also, as have the Washington, Oregon, and California State
fishery agencies. Investigations of high-seas distribution of
salmon have been made by the staffs of our Seattle Biological
Laboratory and the Fisheries Research Institute of the
University of Washington,

Continued exploitation of a fishery resource is possible
because nature makes adjustments to offset the catch that is
made by man. If this were not true, and the numbers of fish
in the sea were always directly in simple proportion to the
numbers that spawned, then continued fishing would lead to
complete extinction of the resource, at a rate proportional

11

to the rate of fishing. With no fishing, of course, there is
no catch, and the potential yield is wasted insofar as man
is concerned. On the other hand, it is obvious that at some
very high rate of fishing it woxold be impossible for the
survivors to produce enough spawn to maintain equally
large catches in later years. But judicious thinning can
produce a steady yield year after year, somewhat as a row
of carrots, or an apple tree, will produce the greatest weight
of crop if thinned or pruned carefully. It is the purpose of
scientific fishery research to determine the relationship
between nxombers of spawners and the size of the commer-
cially-valuable crop they will produce, so that the best
sustained yield can be known and can be maintained by
regulating fishing and other controllable sources of mor-
tality,

Mr, Fredin, of our Seattle Laboratory, in charge of
scientific investigations bearing on the abstention case, will
report to you first. He will be followed by Mr, Atkinson,
Director of our Seattle Laboratory, who will describe
studies of high-seas distribution of salmon, and Dr. Royce,
Director of the Fisheries Research Institute, who will dis-
cuss distribution and movements of salmon as revealed by
tagging.

12

RESEARCH RELATED TO THE CASE FOR ABSTENTION

By R. A. Fredin

Fishery Research Biologist

Bureau of Commercial Fisheries

Biological Laboratory

Seattle, Washington

I shall review the abstention provisions of the North
Pacific Treaty, including their purpose, the stocks of fish
concerned, the conditions under which a stock qualifies for
abstention, and the scientific studies required.

The purpose of the Treaty is to ensure maximum sus-
tained productivity of the fishery resources of the North
Pacific Ocean, To this end, Canada and Japan agreed, in
1953, to abstain from fishing certain stocks of fish in certain
waters, and Canada and the United States agreed to carry out
necessary conservation measures.

Japan agreed to abstain from fishing the following stocks
in certain waters: (1) halibut {Hippoglossus stenolepis)
originating along the coast of North America and which
occur off the coasts of Canada and the United States; (2) her-
ring {Clupea pallasii) of North American origin occurring
off the coasts of Canada and the United States, exclusive of
the Bering Sea and waters of the North Pacific Ocean west
of the nneridian passing through the western extremity of
the Alaskan Peninsula; and (3) the five species of salmon
(Oncorhynchus spp.) originating in the rivers of Canada and
the United States, Because the range of the salmon was
unknown, a provisional line was specified in the Protocol.
Japan and Canada agreed to abstain from fishing these stocks
because, at the time the Treaty was negotiated, it was con-
cluded that each fulfilled the three conditions for abstention,
(1) fvill utilization, (2) regvilated exploitation, and (3) extensive
scientific study.

At the time the Treaty was negotiated it was recognized
that errors in classification might be possible or that
changes in a stock and its fishery might take place. Hence,
the Treaty required that each year, beginning in 1958, the
Commission should determine whether the stocks of halibut,
salmon, and herring continue to qualify for abstention in the
three conditions given above.

In order for the Commission to make the required study,
it has been necessary to assemble scientific data and other
information relating to the three conditions for abstention
for each stock on the abstention list. The task has been and
is a difficult one, particularly with respect to the first condi-
tion for abstention. For a salmon stock, for example, the
scientific evidence relating to the first condition for absten-
tion includes an assessment of the current condition of the
stock, a measure of the intensity of the fishery and the

13

interrelationships of fishing intensity, stock size, and
yield.

To demonstrate how this evidence is used to study the
qualification of a salmon stock for abstention, let us sup-
pose that the relationship between nvimber of spawners
and the nximber of ad\ilt fish they produce resembles the
hypothetical examples in the following table:

Run of Permissible

Number of adult fish catch for

Example spawners they produce sustained yield

1 500 1500 1000

2 1000 2500 1500

3 1500 2000 500

If, from the 1500 adxilt fish in (1) we catch 1000 fish, we
leave 500 spawners to perpetuate the run at an average of
1500 fish. If, from the 2500 adult fish in (2) we catch 1500
fish, we leave 1000 spawners to perpetuate the run at an
average of 2500 fish. If, from the 2000 adtilt fish in (3) we
catch 500 fish, we leave 1500 spawners to perpetuate the
run at an average of 2000 fish. We can say that these catches
of 1000, 1500, and 500 fish represent the average sustained
yield at the three levels of escapement. In this case the
maximum average yield is 1500 fish, and the optim\im
escapement is 1000 spawners.

Suppose that we have a run of 2500 fish annually. If we
catch 1500 and leave 1000 for spawning, we would be f\illy
utilizing the stock while maintaining the escapement at the
level which, on the average, will provide the maximum
sustained yield. It woiold be concluded that more intensive
fishing would not provide a substantial increase in the sus-
tained yield. However, take a case where we have a run of
2000 fish annually, out of which we have always caught only
500 fish and have left 1500 for spawning. These 1500 spawners
provide a long-term yield of 500 fish. By increasing the
fishing intensity to catch 1000 fish instead of 500, the escape-
ment would be reduced from 1500 spawners to 1000 spawners.
These 1000 spawners woxild provide a long-term yield of 1500
fish. Here, then, is a case where naore intensive fishing
would provide a substantial increase in the sustained yield.

For a halibut or herring stock, the scientific evidence
required to determine whether the first condition for ab-
stention is satisfied includes additional data on growth rates,
rates of mortality from natural causes, the age at which the
fish enter the fishery, and the nxomber of years they remain
available to the fishery.

The following example illustrates how growth and natural
mortality rates affect the yield to be obtained from a given
number of fish. Suppose we have a group of 1000 fish which
is going to be available to us for one year, and that we could
catch any or all of them at any one time during the year. Let
us say that, at the start of the year, each fish weighs 5

14

pounds. Thus, if we harvest them all at the start of the year,
our yield would be 5000 pounds. Suppose that we let the fish
remain for the year, that none of them dies from naturcd
causes during the year, and that each fish gains one pound
in weight. At the end of the year, the available catch is 6000
pounds. Therefore, catching the fish at the end of the year
rather than at the start, our yield increased by 1000 povmds,
because the gain in weight exceeded the loss due to natural
mortality.

On the other hand, suppose that during the year we let
the fish remain, 500 of them died from natural causes,
leaving only 500 for harvesting at the end of the year. The
yield at the end of the year would be 500 times 6 pounds, or
3000 pounds. The yield would be ZOOO pounds less than it
would have been had we harvested at the start of the year,
because the loss due to natural mortality exceeded the gain
in weight by the survivors. Similar knowledge of the growth
and natural mortality of halibut and herring enable us to
estimate when and how much fishing shovild be employed to
obtain the ma:ximum yield from a given number of fish
entering the fishery. If the current fishing intensity is lower
than that which provides the estimated maximum yield, we
wovild conclude that an increase in fishing would provide an
increase in yield. If the current fishing intensity is at or
above that which provides the estimated maximum yield,
we would conclude that more intensive fishing would not
provide an increase in yield.

Another type of evidence can be used to study the quali-
fication of a stock for abstention. It consists of the historiced
changes or trends in catch, fishing effort and relative abun-
dance of a stock. The conclusions to be drawn from this type
of evidence are usually rather general. Nevertheless, they
are, if logically, drawn, based on the same biological prin-
ciples and concepts as those drawn from the more rigorous
analytical treatment of return-escapement data orgrowthand
natural mortality data.

With regard to the second condition for abstention, it is
necessary to demonstrate that our reg\ilatory measures are
designed for the purpose of achieving maximum sustained
yield, and that they are based on the findings of scientific
research.

For the third condition for abstention, it is necessary to
explain the scope and objectives of our research programs.
It should be emphasized that, unless the third condition for
abstention has been and is reasonably satisfied, we lack the
scientific evidence required to study the qualification of a
stock under the first condition for abstention and to serve
as a basis for regulatory measures. Clearly, the three con-
ditions for abstention are closely related.

During the past three years, we have assembled various
types of scientific data concerning utilization of our stocks
and other information relating to regulation of and research
studies on the stocks. These data and information represent
a body of knowledge on our salmon, halibut and herring

15

stocks which had not been gathered together prior to the
negotiation of the treaty, and they constitute a significant
advance in the science of fishery conservation. This has
been presented to the Commission in the form of seven
major technical docxaments and about twenty other supporting
documents, which have been our cases for abstention to date.
Without a doubt, additional documents will be required, for
while our cases for abstention are for all reasonable pur-
poses conclusive, they are not, and never can be expected to
be, entirely perfect.

For salmon, we have presented evidence which shows
that, for several years following World War II, a greatly
intensified United States fishery failed to provide an increase
in yield. We have also shown, for most of ournnajor red {0.
nerka) and pink {0. gorbuscha) salmon-producing areas, that
recent spawning escapements have been lower than those
escapements associated with the larger average yields. We
have concluded from this that more intensive fishing woiold
further reduce escapements and probably would result in a
decrease, not an increase, in the sustained yield. Indeed,
with regard to Bristol Bay red salmon, which Canada ab-
stains from fishing, the Canadian Section agreed with this
conclusion at the last annual meeting of the Commission,

However, the Japanese Section of the Commission has
stated that we have not yet demonstrated that more intensive
exploitation of our salmon stocks would not provide a sub-
stantial increase in yield which covild be sustained. Their
scientific argiunents have been based on the hypothesis that
the long-term average yield from a salmon stock is pri-
marily controlled by natural factors, and that fishing plays
a relatively minor role. This problem of separating the
effects of a fishery from those of the environment is a diffi-
cult one, and it will be necessary to examine the logic of
Japanese scientific argximents regarding the effects of fish-
ing on salmon stocks and to demonstrate, with supporting
data, the weaknesses of their logic. In addition, it is im-
portant that we gather the scientific evidence required to
determine whether or not a high-seas salmon fishery results
in a waste of the salmon resources.

For North American halibut stocks, we have presented
one document on the history of the changes in the stock and
the fishery, and another on the yield to be expected at various
levels of fishing intensity under present-day conditions of
growth and natural mortality. This latter docvunent is a
significant contribution to our knowledge of the halibut stocks.
The scientific data indicate, for halibut stocks outside the
Bering Sea, that present-day fishery is taking almost the
maximum yield from the stocks, and that greatly intensified
fishing would provide only a relatively small increase in
yield, Canadian scientific reports on halibut have reached
essentially the same conclusions,

Japan has stated that we have not yet demonstrated that
more intensive fishing of the halibut stocks would not provide
a substantial increase in yield which could be sustained,

16

Their principal scientific argximent has been that we do not
know the relation between stock size and production of new
halibut of commercial size. It will be necessary for us to
study the logic of this argument that such information is
necessary to the management of a marine species such as
halibut.

The third species of fish of United States origin on the
abstention list in 1953 was Alaska herring. Within the past
year, some important new scientific evidence was assembled
for Alaska herring, and this was reviewed at the last annual
meeting of the Commission,

The new scientific evidence consisted of information on
levels of fishing intensity during the past five or six years,
natural mortality, and growth rates. These data showed that
after herring are three or four years old, natural losses in
numbers of fish far exceed the weight increases of the sur-
vivors. The data also showed that present-day fishing
intensity is low, much lower than during the years preceding
negotiation of the Treaty, and considerably below the levels
which would provide higher sustained yields.

The conclusion drawn from the scientific evidence was that
more intensive fishing of Alaska herring would, with reason-
able certainty, provide a substantial increase in yield which
could be sustained. This conclusion was agreed upon by
scientists of Japan, Canada, and the United States,

17

DISTRIBUTION AND RACIAL COMPOSITION OF
SALMON ON THE HIGH SEAS

By Clinton E. Atkinson
Director, Biological Laboratory
Bureau of Commercial Fisheries
Seattle, Washington

The Protocol to the International Convention for the High
Seas Fisheries of the North Pacific Ocean directs the Com-
mission **to investigate the waters of the Convention area to
determine if there are areas in which salmon originating in
the rivers of Canada and of the United States of America
interm.ingle with salmon originating in the rivers of Asia*',
and to "conduct suitable studies to determine a line or lines
which best divide salmon of Asiatic origin, and sadmon of
Canadian and United States of American origin*'. Since its
organization the United States Section of the Commission has
conducted extensive investigations on the problems of the
Protocol to determine whether or not the present provisional
line at 175° W. (fig, 1) adequately protects North American
runs of salmon from exploitation by the Japanese fisheries.
The resvilts of research to date show that the provisional line
protects most North American runs of salmon with the
exception of Bristol Bay red satlmon which range far to the
westward and into the area of high seas fishing.

150°

1

I60» I70» l«
\ \ \ \ \ ^

0'

170* I60« 150° 140* 130'
K^ H-^l 1 1 ' 1 1 1 1

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Figure l.--North Pacific Ocean and Bering Sea, showing position of
Provisional Abstention Line.

18

At the time the treaty was signed, almost no information
was available on distribution of Asian or North American
salmon on the high seas. It is true that the Japanese in the
1930*s had vmdertaken a detailed survey of the Bering Sea
west of 180°, but the main purpose of their survey was to
determine where Scdmon were most abundant for purposes
of establishing a commercial fishery, and no attention was
given to whether the fish taken were of Asian or North
American origin. The limited research of the United States
in 1937 and 1938 in eastern Bering Sea indicated that salmon
were probably confined to the continental shelf.

After entry into force of the Treaty on June 12, 1953, the
Commission was organized in February of 1954 and its pro-
gram of research was approved in the fall of that same year.
The first explorations to determine distribution of salmon
were made in the spring of 1955 when the U. S. Fish and
Wildlife Service vessel John N. Cobb was sent out along the
west coast of North America, across the Gulf of Alaska, and
along the Alaskan Peninsula. Wherever the Cobb set its nets,
salmon were taken.

Based upon this information, two halibut schooners were
chartered in July 1955 to investigate the critical waters
between 175° E. and 165° W, lying on both sides of the pro-
visional line. Again, they took salmon all along the Aleutian
Islands north of about 48° N, But when the boats passed into
more southern waters, salmon disappeared from their
catches and instead, quantities of edbacore were taken. It
was now obvious that two separate environments had been
found. This was most important to us because it meant that
we had found the southern range of salmon distribution (fig. 2),

170» 180

40° I30»

Figure 2.- -North Pacific Ocean and Bering Sea showing area inhabited by
salmon in May - June.

19

However, further evidence was required on distribution
of salmon in spring (winter in the sea) when the colder water
of the North Pacific extends as far south as about 40° N.
Arrangements, therefore, were made for vessels from the
laboratory of the Bureau of Commercial Fisheries at Hono-
lulu to extend their spring cruise for tuna into waters north
of 40° N. and, as predicted, salmon were found in these
waters. It was evident that the distribution of salmon was
intimately associated with conditions in the ocean, varying
from season to season and, of course, from year to year.

Coupled with this knowledge of the southern limit of sal-
mon distribution, subsequent studies have shown that the
northern limit lies at a temperature of about 3° C, and here
again the temperature pattern varies markedly between
seasons and years.

Yearly changes in abundance of salmon have be en followed
closely since 1955 by fishing the sajiae stations on the high
seas. In this work we discovered that the numbers, kinds,
and sizes of salmon on the high seas vary from time to time
and place to place. For example, we have found the ocean
near the central Aleutian area to be heavily poptilated with
pink salmon {Oncorhynchus gorbuscha) during odd-numbered
years, and we have found that these are Asian fish. In marked
contrast, very few pink salmon are present in the even-
numbered years, and these fish are predominantly of North
American origin. Pink salmon invariably return to spawn at
the end of their second year of life, hence these patterns are
not surprising.

The distribution of salmon within this area varies as the
season progresses. In 1959 pink salmon were first observed
in large numbers about 200 miles south of the Aleutian chain.
As the summer progressed, pink salmon became more and
more abundant near and north of the Aleutian chain in the
Bering Sea, but by mid-Jxily they co\ild be found only in the
westernmost part of the ocean, near the Asian continent.

Similar changes have been foundfor red salmon (0. nerka).
In May and Jxine of 1959, the central area just north of the
Aleutians was heavily populated with adult red salmon almost
certainly of Bristol Bay origin, and red salmon remained
abundant here until about the end of June, In July, the larger,
more mature red salmon became scarce but we began to
catch large numbers of immature red salmon. In 1959
these immature red salmon were about 10 times more
abundant than in previous years and were certainly part of
the very large outmigration of small fish from Bristol Bay
in 1958.

These initial explorations were sufficient to give us an
answer to the first question posed by the Protocol, that is,
did Asian and North American salmon intermingle on the
hign seas? There is no question but that large numbers of
salmon from Asia and North America intermingle in the
mid- Pacific and the Bering Sea. We also found that the
amount of mixing and the actual distribution of the salmon
was related to the abundance of fish from certain mainland

20

rearing areas and to the configuration of the hydrography of
the sea.

Our next problem was to define this area of mixing for
the three important species of salmon: red, pink and chum
{0. keta) salmon. Tagging experiments provided the best way
to define these areas, and such investigations were arranged
by contract with the Fisheries Research Institute of the
University of Washington,

Finally, to answer the problem set forth in the Protocol,
we must know not only where salmon are, but also the rela-
tive abundance of North American salmon at any point on the
high seas. The answer to this question required the develop-
ment of new methods for identifying Asian and North Ameri-
can fish. In effect, we must examine a salmon, and by certain
differences, such as variations in size, shape, or numbers
of parts in various sections of the body, be able to say that
this fish is from Asia or from North America, Three suc-
cessfxil methods for identifying stocks of salmon are now
being used.

These areas of the North Pacific Ocean mentioned above
were all fished by our research vessels for the purpose of
securing samples to determine where fish in the high seas
originated. In studying these fish samples, examination of
the structure of scales of individual fish was the first
approach followed. It has been found that salmon tend to
deposit rings (or circvili) on their scales in patterns charac-
teristic for each area, A careful study of these characters
of red salmon scales demonstrated by 1957 that Bristol Bay
red salmon were fovind far to the west in the central Pacific,
Subsequently, we have devised means of making quantitative
separations into continent of origin of scale ssmnples taken
on the high seas.

Similarly, we have experienced considerable success in
the study of the coxints of body structures of salmon. This
different approach makes use of variations in the number of
scales on the fish, bones in the backbone, bones in the gill
arches, and fin rays, as well as a number of other readily-
examined portions of the fish which tend to show differences.
This method has been particularly useful to us in developing
quantitative separation of red salmon on the high seas. We
have been able to determine with reasonable precision what
portion of the salmon in a sample taken in the middle of the
ocean came from North America and what portion Ceime
from Asia,

One of the newer and more fascinating approaches, or
techniques, applied is that of serological or blood chemistry
differences between Asian and North American fish. It has
been necessary to develop this research from a rather
scanty basis of knowledge of blood types in fish. However, it
has been found that salmon and other fishes do indeed have
blood types. It has been possible to produce antisera which
will react with the blood of North American red salmon but
will not react with the blood of Asian red salmon. By this
means it is possible to collect samples of blood on the high

21

seas and, subsequently to determine whether the blood was
from Asian or North American fish, although the fish may
have been taken thousands of miles from its point of origin.

To siommarize briefly the results and progress at this
point, we have worked out, for the years during which
research has been possible, a picture of the distribution of
North American red, pink, and chum salmon on the high
seas.

For red salmon it has been found that Bristol Bay fish
are dominant in the Aleutian area as far west as 175° E.
longitude; that is, a matter of about three-fourths of the
distance from Bristol Bay to Kamchatka (fig, 3). Asian fish
in smadler numbers are found as far east as the eastern
Aleutian Islands,

Figure 3.- -Distribution of western Alaska red salmon in 1957. In the shaded areas, western
Alaska-type red salmon were dominant, and their relative abundance was proportional
to the depth of the shading.

Pink sailmon from the Bering Sea coast of North America
were found very nearly as far west as Bristol Bay red
salmon; however, not nearly so abundantly. Conversely,
Asian pink salmon in 1957, and apparently also in 1959i were
found as far east as the tip of the Alaska Peninsula in very
considerable numbers. It seems that in these odd-numbered
years Kamchatka fish overwhelmingly dominated the entire
mid-Aleutian pink salmon population,

Chxim salmon were distributed in approximately the same
manner as pink salmon. Asian chums have been caught near
the Shumagin Islands, and North American chums, while they
go far to the west, do not appear actually to reach the Asian
mainland. Again, the numbers of Asian chum Scdmon in
mid-ocean appear to far outnumber those from North America.

22

The resiilts of racial studies provide two important
answers related to problems of the Protocol. First, infor-
mation on the extent of mixing of the salmon on the high seas
is further strengthened. The east-west extent of the mixing
area is shown in figure 4, North American red salmon, the
species of greatest concern, have been recognized by the
Commission to predominate in catches as far west as 175°
E; these red salmon originated in the Bristol Bay region.

Figure 4.--East-west extent of high seas mixing between American and Asian salmon.
The area observed was near the Aleutians. The bars indicate for each species the range
of latitude over which American and Asian fish are commonly found in the same waters.

But the most important problem at this time is raised by
the information on proportions of Bristol Bay red Seilmon
found in various areas of the high seas (fig. 1), Even though
the data presented here are only of the most general nature,
the chart does show the extent of the Bristol Bay red salmion
runs which migrate beyond the provisional line and are
subject to capture by the Japanese fishery. This is the
problem of the Protocol now before the Commission.

23

PACIFIC SALMON IN INTERNATIONAL WATERS^

Presented by

William F. Royce

Director, Fisheries Research Institute

University of Washington

Seattle, Washington

Intensive research in the past several years has shown
that the five species of Pacific salmon (genus Oncorhynchus)
and steelhead trout {Salmo gairdneri ) travel tremendous
distances in their ocean migrations. American salmon travel
so far west, and Asian salmon so far east, that stocks from
both continents are found mixed throughout a large part of the
central North Pacific Ocean and Bering Sea. Some king or
Chinook salmon {0. t skawytscka) born in the gravels of the
Salmon River in the State of Idaho range at least as far as
the central Aleutian Islands before maturing and returning
again 2,500 miles to ascend the Columbia River enroute
home. Occasional red or sockeye salmon {0. nerka) from
lakes in British Columbia swim westward at least to 177° E.
longitude, well over halfway to Asia, in their ocean travels.
Chum salmon (0. keta) from southeastern Alaska naay make
a round trip of 3,500 miles to the central Aleutians in their
quest for food at sea, Steelhead trout from rivers of the
State of Washington and Oregon also may wander at least to
the central Aleutians in their seaward journeys.

Likewise chum salmon and pink salmon (0. gorhuscha)
from many Asian spawning areas are found feeding along the
Aleutian chain as far eastward as the Alaska Peninsula, a
distance of 1,000 to 1,500 miles from their nated streams.
Ch\ims in the rich ocean feeding areas at the base of the
Alaska Peninsula often are a mixture originating from such
diverse spawning grounds as the Anadyr River in the Siberian
Arctic, various rivers tributary to the Sea of Okhotsk,
streams on the island of Hokkaido, Japan, and, as already
mentioned, streams in many parts of Alaska, Silver or coho
salmon (0. kisutch) from east Kamchatka range seaward to the
central Aleutians (175° W.) a distance ofatleast 1,000 miles.

High-seas salmon tagging has been conducted since 1955
by the Fisheries Research Institute of the College of Fish-
eries of the University of Washington under contract to the
United States Bureau of Commercial Fisheries. Tagging is
also being done on a smaller scale by the Canadian and
Japanese sections of the Commission, and the three programs
have been integrated as far as practicable.

Tagging salmon on the high seas has proved much more dif-
ficult than tagging in coastal areas. Large specially -designed

* Prepared by Allan C. Hartt, Fishery Research Institute, University of Washington for
presentation at the North American Wildlife Conference. Dallas, Texas. March 7-9. 1960.

24

purse seines were developed for capturing salmon in the
open sea in good condition for tagging. Brailing nets and
holding tanks were designed for handling salmon with mini-
mvim injury. Experiments were needed to find tags that would
give maxim\am returns after 1 or 2 years on rapidly- growing
fish. Identification of the several species of salmon, not
normally a problem in coastal areas where fish are mature,
was a problem at sea. Catches often included all five species
and many age groups. Rapid identification of the younger
fish sometimes only 8 to 10 inches long required practice.
Sccde samples were taken from all fish tagged for later
positive identification. A toted of 48,296 salmon and steelhead
have been tagged over the 5 years, and 1,128 have been
returned to date. The overall rate of return (2,3 percent)
is based on all salmon tagged, including immatures, which
of course yield fewer returns than matures. Returns of
mature salmon, those destined to spawn in the year of
tagging, average nearly 10 percent, Immatures may spawn
1, 2, or 3 years later, and some of those still at liberty will
be recovered in I960 and 1961, Returns from centrad Pacific
experiments have come from Japan, the U.S.S.R. , Alaska,
Canada, Washington, Oregon, and Idaho, and from the Japa-
nese high seas gill net fishery in the North Pacific Ocean
and Bering Sea.

Each year, results of tagging have disclosed new and
valuable data on ocean habits and movements of salmon.
The abxindance and migration patterns of the several species
have been fovind to vary tremendously from year to year, so
that continued observations are needed to answer fully the
questions implicit in the North Pacific Treaty.

A sximmary of resxilts to date for all species is presented
in figures 5 to 8, Tagging areas are shown by circles, and
recovery locations by arrowheads. The thickness of lines
indicates approximate relative numbers of fish to a given
destination. Liines are not intended to show exact routes, but
are drawn diagrajumatically for simplicity. Fish are shown
moving westward prior to going through Aleutian passes
because purse- seine catches indicated a positive westward
movement through tagging areas south of the Aleutians. In
evaluating the four figures, it must be borne in nriind that
most tagging was in the areas along the Aleutians from 160^
West to 170*^ East longitude. Mature salmon, of course, are
recovered only in the year of tagging, while immatures are
recovered 1 or 2 years later (except for some few immatures
which were taken by the Japanese high seas gear in the year
of tagging). Since tagging was conducted at numerous loca-
tions each year from May to September, returns may be
considered representative of summer stocks in the Aleutian
area.

Red salmon returns (fig. 5) indicate the overwhelming
predominance of American red salmon along the entire
Aleutian Chain in the North Pacific and Bering Sea. A total
of 215 was returned from Bristol Bay, but only one from
Asia. The destingation of a few others is uncertain. The

25

Figure 5.- -Generalized distribution pattern of tag returns from red salmon tagged at sea

from 1956 to 1959.

distribution of returns is in keeping with what we know about
relative production in Asia and America; red salmon pro-
duction in Bristol Bay alone is probably greater than that of
Asia.

Chum salmon (fig. 6) show quite a different picture, for
those tagged in the Aleutians yielded 146 returns from Asia,
and 52 frora Alaska. Nearly all Alaskan returns were from
releases in the eastern Aleutians. Again results are in
harmony with relative production in the pertinent recovery
areas; Asian chum salmon production is much greater than
that of northwest Alaska, Alaskan chiims are present at least
to 177° West. The lone return to southeast Alaska indicates
that few chums from this source travel as far as the central
Aleutians.

Pink salmon returns (fig. 7) show a still different picture.
It should be noted here that pink salmon have a very uniform
2-year life history, and in many areas throughout their
range, runs have a pronounced cyclic abvmdance in odd or
even years. In odd years (1957 and 1959), pinks were abiuidant
in the Aleutian tagging areas, and tag returns came only from
east Kamchatka or were intercepted at intermediate points
on the high seas by the Japanese fleet. (In 1955, tagging
consisted of small-scale preliminary experiments only as
far west as Kodiak Island.) In even years (1956 and 1958),
pinks were present in relatively small numbers, but all
coastal returns were from Alaska. Those taken on the high
seas, as shown, had an uncertain destination, but it is
noteworthy that runs to east Kamchatka were large in 1957
and 1959, and smadl in 1956 and 1958. Although other Asian
production areas (west Kamchatka, for example) have very
large runs in even and odd years, these areas have yielded
no pink scdmon returns to date. East Kamchatkan pink runs
are many times larger than those to northwest Alaska, at
least in odd years. The few pinks tagged in the Gxilf of Alaska

26

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Recovery area

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Figure 6.- -Generalized distribution pattern of tag returns from chum salmon tagged at

sea from 1956 to 1959.

Figure 7.--Generalized distribution pattern of tag returns from pink salmon tagged at

sea from 1956 to 1959,

indicate that some of this species cross the Gulf from
southeastern Alaska.

Results of tagging king and silver salmon and steelhead
trout, as mentioned previously, have demonstrated that these
species travel spectacxilar distances at sea, but numbers
tagged and recovered have been too small for conclusions
as to relative importance of Asian and American stocks
in the areas of intermingling. In figure 8 each arrow indi-
cates only one tag return. To date, returns of kings and
steelhead have come only from America, but silvers have
come from both continents. American production of kings
and steelhead is far greater than Asian.

Thus, tagging to date has shown a mixture of American
and Asian salmon in ocean areas fished by the Japanese

27

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Figure 8.- -Generalized distribution pattern of tag returns from king and silver salmon
and steelhead trout tagged at sea from 1956 to 1959.

high seas fleet. Red salmon are overwhelmingly American
(Bristol Bay) across the full length of the Aleutians. Chums
are a mixture, and Asian fish probably predominate in areas
west of 170° West longitude. Pinks are abundant and over-
whelmingly Asian in odd years, whereas in even years this
species is scarce, but principally American in origin.

The problem of boundaries of distribution of Asian and
American salmon is thus made more complex by the dis-
similar distribution of the several species. These distri-
butions can be expected to vary annually in accordance with
relative abundance and perhaps according to varying migra-
tion patterns, oceanographic conditions, and the like.

Canadian and United States regulations prohibit all szilmon
fishing, except some trolling, on the high seas. This permits
much more effective regulation since intensity of fishing
upon rtms to individual rivers may be regulated according
to size of runs. Depleted stocksmay be protected, and healthy
runs fished more. High seas harvesting permits no such indi-
vidual controls and cilso takes many immature salmon.

This paper presents a brief outline of results to date of
one phase of a large research program on Pacific salmon at
sea. In addition to providing data for the purposes of the
International North Pacific Fisheries Conunission, the re-
search is providing a wezilth of new information on the ocean
biology of scdmon. The saltwater life-history of salmon and
steelhead is proving no less remarkable than their much-
studied yet little-understood freshwater life-history.

MS. 978. 5-60
28

6P0 89 368 5

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