NOAA Technical Report NMFS SSRF-690
Migratory Routes of Adult Sockeye Salmon, Oncorhynchus nerka, in the Eastern Bering Sea and Bristol Bay
RICHARD R.STRATY
SEATTLE, WA
April 1975
NATIONAL OCEANIC AND National Marine ATMOSPHERIC ADMINISTRATION Fisheries Service NOAA TECHNICAL REPORTS
National Marine Fisheries Service, Special Scientific Report—Fisheries Series
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investigations that document long-term continuing programs .1 Scientific Report— Fisheries series was established in 1949. The series carries reports on scientific intensive scientific reports on studies of restricted scope. The reports may deal with applied fishery problems. The series is also used as a medium for the publica- — u... .f ...... 1:...^ scientific nature. (F are available free in limited numbers to governmental agencies, both Federal and State. They are also available in exchange for ns in the marine sciences. Individual copies may be obtained (unless otherwise noted) from D83, Technical Information Division, Emiiunmcnlal Science Inlormatiun Center, NOAA, Washington. D.C. 20235, Recent SSRF's are:
635. A bibliography of the blackfin tuna, Thunnus atlanticus (Lesson). By Grant L. lit. Macrozooplankton and small nekton in the coastal waters off Vancouver Island
iii Beardsley and David C. Simmons. August 1971. 10 pp. For sale by the Superintendent of ' 197 1 + anada) and Washington, spring and fall of 1963. By Donald S. Day. January , Documents, U.S. Government Printing Office. Washington. D.C. 20402. I pp.. 19 figs.. 13 tables.
636. Oil pollution Wake Island from the tanker R. Stoner. Regmald 620. The Trade Wind Zone Oceanography Pilot Study. Part IX: The sealevel wind field on C. By M. Gooding. 1971. iii -f 12 8 figs.. 2 tables. For sale by the Superintendent of and wind stress values, July 1963 to June 1965. By Gunter R. Seckel. June 1970, iii + 66 May pp., Documents. U.S. Government Printing Office. Washington, D.C. 20402. pp.. 5 figs.
637. Occurrence of larval, juvenile, mature crabs in the vicinity of Beaufort Inlet. 621. Predation by sculpins on fall chinook salmon. Oncorhynchus tshawytscha, fry of and North Carolina. By Donnie L. Dudley and Mayo H. Judy. August 1971. iii -f 10 pp.. 1 fig.. hatchery origin. By BerOamin G. Patten. February 1971, iii + 14 pp., 6 figs,. 9 Ubles. 5 tables. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 622. Number and lengths, by season, of fishes caught with an otter trawl near Woods Hole, Massachusetts, September 1961 to December 1962. By F. E. Lux and F. E. Nichy. 638. Length-weight relations of haddock from commercial landings in New England, Februar>' 1971. iii + 15 pp.. 3 figs.. 19 tables. 1931-55. By Bradford E. Brown and Richard C. Hennemuth. August 1971. v -I- 13 pp.. 16 figs., 6 tables, 10 appendix A tables. For sale by the Superintendent of Documents, U.S. -J3. Apparent abundance, distribution, and migrations of albacore. Thunnus alatunga, Government Printing Office, Washington. D.C. 20402. on the North Pacific longline grounds. By Brian J. Rothschild and Marian Y. Y. Yong. September 1970, v + 37 pp.. 19 figs.. 5 tables. 639. A hydrographic survey of the Galveston Bay system. Texas 1963-66. By E. J. PuUen,
W. L. Trent, and G. B. Adams. October 1971. v -I- 13 pp.. 15 figs.. 12 tables. For sale by the 624. Infiuence of mechanical processing on the quality and yield of bay scallop meats. By Superintendent of Docutnents, U.S. Government Printing Office. Washington. D.C. N. B. Webb and F. B. Thomas. April 1971. iii + 11 pp.. 9 figs., 3 tables. 20402.
25. Distribution of salmon and related oceanographic features in the North Pacific 640. Annotated bibliography on the fishing industry and biology of the blue crab. Ocean, spring 1968. By Robert R. French, Richard G. Bakkala. Masanao Osako, and Jun CatUnectes sapidus. By Marlin E. Tagatz and Ann Bowman Hall. August 1971. 94 pp. For Ito. March 1971, iii + 22 pp.. 19 figs., 3 tables. sale by the Superintendent of Documents. U.S. Government Printing Office, Washington. DC. 20402. 626. Commercial fishery and biology of the freshwater shrimp, Macrobnchium, in the Lower St. Paul River. Liberia. 1952-53. By George C. Miller. February 1971, iii + 13 pp.. 8 641. Use of threadfin shad, Dorosoma petenense, as live bait during experimental pole- figs., 7 tables. and-line fishing for skipjack tuna. Katsuwonus pelamis, in Hawaii. By Robert T. B.
Iversen. August 1971. iii + 10 pp., 3 figs.. 7 tables. For sale by the Superintendent of 627. Calico scallops of the Southeastern United States, 1959-69. By Robert Cummins, Jr. Documents. U.S. Government Printing Office. Washington. DC. 20402. June 1971. iii + 22 pp.. 23 figs.. 3 tables.
642. Atlantic menhaden Breuoortia tyrannus resource and fishery— analysis of decline. Investigations. 1969. Marine Biological Laborator\. 628. Fur Seal By NMFS, Mammal By Kenneth A. Henry. Augtist 1971. v -t- 32 pp.. 40 figs.. 5 appendix figs., 3 tables, 2 August 1971, 82 pp.. 20 figs.. 44 tables, 23 appendix A tables. 10 appendix B tables. appendix tables. For sate by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC. 20402. 629. Analysis of the operations of seven Hawaiian skipjack tuna fishing vessels. June- August 1967. By Richard N. Uchida and Ray F. Sumida. March 1971. v -H 25 pp.. 14 figs.. 643. Surface winds of the southeastern tropical Atlantic Ocean. By John M. Steigner and 21 tables. For sale by the Superintendent of Documents, U.S. Government Printing Of- Merton C. Ingham. October 1971, iii + 20 pp , 17 figs. For sale by the Superintendent of fice. Washington. D.C. 20402. Documents. U.S. Government Printing Office. Washington. DC. 20402.
630. Blue crab meat. I. Preservation by freezing. July 1971, iii -t- 13 pp.. 5 figs., 2 tables, 644. Inhibition of fiesh browning and skin color fading in frozen fillets of yelloweye n. Effect of chemical treatments on acceptability. By Jurgen H. Strasser, Jean S. Lennon. snapper [Lutzanus uiuanus). By Harold C. Thompson. Jr.. and Mary H. Thompson.
iii -t- 1 fig.. tables. and Frederick J. King. July 1971. 12 pp.. 9 February 1972, iii + 6 pp., 3 tables. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 631, Occurrence of thiaminase in some common aquatic animals of the United States and Canada. By R. A. Greig and R H. Gnaedinger. July 1971. iii •(• 7 pp., 2 Ubles. 645. Traveling screen for removal of debris from rivers. By Daniel W. Bates, Ernest W.
Murphey, and Martin G. Beam. October 1971, iii + 6 pp., 6 figs., 1 table. For sale by the
{2. An annotated bibliography of attempts to rear the larvae of marine fishes in the Superintendent of Documents, U.S. Government Printing Office. Washington. D.C. .aboratory. By Robert C. May. August 1971, iii + 24 pp.. 1 appendix I table. 1 appendix II 20402. table. For sale by the Superintendent of Documents, U.S. Government Printing Office. Washington. D.C. 20402. 646. Dissolved nitrogen concentrations in the Columbia and Snake Rivers in 1970 and their effect on chinook salmon and steelhead trout. By Wesley J. Ebel. August 1971. iii + 7
633. Blueing of processed crab meat. II. Identification of some factors involved in the pp.. 2 figs.. 6 tables. For sale by the Superintendent of Documents. U.S. Government 1,1,,.. ,i,.,.,,i.,ra,„.n .,f canned crab m^ni (•„)/,„»,>,. v,„ir,y.,> Rv \1,.lv.n K \v.,i,.rs Mbv Printing Office, Washington, D.C. 20402.
: , 3 tables.
647. Revised annotated list of parasites from sea mammals caught off the west coast ot
North America. By L. Margolis and M. D. Dailey. March 1972. iii -^ 23 pp. For sale by the 634. Age composition, weight, length, and sex of herring. Clupea paliasit, used for reduc- Superintendent of Documents, U.S. Clovernment Printing Office, Washington, D.C. (i.,n in AI^^W» iq'»l.*^ Rv r„.rHlH M Rfui ,lii|v I4T1 li, + -'S iin 4 fu-s IK tHltics
Continued on inside I t-iiJK;-:.
NOAA Technical Report NMFS SSRF-690
Migratory Routes of Adult Sockeye
Salmon, Oncorhynchus nerka,
in the Eastern Bering Sea
and Bristol Bay
RICHARD R.STRATY
SEATTLE, WA
April 1975
j£»™JS»^f
UNITED STATES / NATIONAL OCEANIC AND / National Marine DEPARTMENT OF COMMERCE / ATMOSPHERIC ADMINISTRATION / Fisheries Service Rojers C. B. Morton, Secretary / Robert M, White. Administrator / Robert W Schoning. Director The National Marine Fisheries Service (NMFS) does not approve, rec- ommend or endorse any proprietary product or proprietary material mentioned in this publication. No reference shall be made to NMFS, or to this publication furnished by NMFS, in any advertising or sales pro- motion which would indicate or imply that NMFS approves, recommends or endorses any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly the advertised product to be used or purchased because of this NMFS publication. CONTENTS Page
Introduction 1 The sockeye salmon fishery of Bristol Bay 2 Determining the distribution and migratory pattern of Bristol Bay sockeye salmon .... 3 Offshore distribution 3 Exploratory fishing 3 Results of exploratory fishing 3 Synopsis: Distribution of sockeye salmon in the eastern Bering Sea and Bristol Bay during spawning migration 6 Offshore tagging 6 Results of tagging 9 Synopsis: segregation of sockeye salmon stocks in the eastern Bering Sea and outer Bristol Bay H Inshore distribution 12 Capturing and tagging fish and recovery of tags 12 Analysis of recovery data 12 Interpretation of tagging results 16 Distribution of sockeye salmon stocks occurring on the east and west sides of inner Bristol Bay 17 Distribution of Ugashik River sockeye salmon in inner Bristol Bay 18 Distribution of Egegik River sockeye salmon in inner Bristol Bay 18 Distribution of Naknek and Kvichak River sockeye salmon in inner Bristol Bay 21
Distribution of Nushagak Bay sockeye salmon stocks in inner Bristol Bay . . 22 Synopsis: Segregation of sockeye salmon stocks in the inshore region of Bristol Bay 24 Synopsis of distribution and migratory routes of sockeye salmon in the eastern Bering Sea and Bristol Bay 24 Summary 25 Literature cited 25 Figures
1. Principal sockeye salmon river systems in Bristol Bay 2 2. Transects in the eastern Bering Sea and outer Bristol Bay where exploratory fishing was carried out in the 8 yr selected for study to determine the distribution of sockeye sal- mon in offshore area of Bristol Bay 4 3. Gill net catches of sockeye salmon along approximately long. 170°W, 17-28 June 1958. 4 4. Gill net catches of sockeye salmon along approximately long. 170° W, 27 June-3 July 1959. 5 5. Gill net catches of sockeye salmon along approximately long. 170° W, 12-25 June 1961. 5 6. Gill net catches of sockeye salmon between Cape Mordvinof and Pribilof Islands, 6 June- " 3 July 1940 5 7. Gill net catches of sockeye salmon between Pribilof Islands and Nunivak Island, 17-21 June 1940 5 8. Gill net catches of sockeye salmon between Cape Mordvinof and Nunivak Island, 7-11
July 1941 • 5 9. Gill net catches of sockeye salmon along approximately long. 161°30'W, 24 June-6 July 1965 and 1966 6 10. Gill net catches of sockeye salmon between Cape Seniavin and Cape Newenham, 27
June-23 July 1939 . 10 11. Distribution of sockeye salmon in eastern Bering Sea and Bristol Bay during spawning migration, showing main migration route. Distribution was determined from results of exploratory fishing 7 12. Areas of tagging by United States and Japan in the 6 yr selected for study to determine the distribution of sockeye salmon stocks in offshore area of Bristol Bay 9 13. Distribution of tags recovered in catch (commercial fishery) and observed in the escape- ments from sockeye salmon released at nine tagging sites in Naknek-Kvichak and Egegik fishing districts (inshore area) in 1955 13
iii 14. Distribution of tags recovered in catch (commercial fishery) and observed in the escape- ments from sockeye salmon released at 10 tagging sites in Nushagak and Naknek- Kvichak districts (inshore area) in 1956 14 15. Distribution of tags recovered in catch (commercial fishery) and observed in the escape- ments from sockeye salmon released at 10 tagging sites in Naknek-Kvichak, Egegik, and Ugashik fishing districts (inshore area) in 1956 15 16. Distribution of tags recovered in catch (commercial fishery) and observed in the escape- ments from sockeye salmon released at two tagging sites in Naknek-Kvichak fishing district (inshore area) in 1957 16 17. Distribution of tags recovered in catch (commercial fishery) and observed in the escape- ments from sockeye salmon released at four tagging sites in Nushagak fishing district (inshore area) in 1959 17 18. Distribution of tagged sockeye salmon in the Igushik, Wood, Kvichak, Naknek, and other Nushagak Bay river escapements, Bristol Bay, 1956 and 1959 19 19. Distribution of tagged sockeye salmon in the Kvichak, Naknek, and Egegik River escape- ments, Bristol Bay, 1955 and 1956 20 20. Distribution in the spawning escapement of 1.3 and 2.3 age groups of sockeye salmon
tagged at seven sites in the Naknek-Kvichak and Egegik fishing districts in 1955 . 21 21. Percentage distribution of recoveries within the Nushagak fishery of sockeye salmon tag- ged at four sites in the Nushagak district 23 22. General distribution of Bristol Bay stocks of sockeye salmon, showing area of greatest stock abundance 24
Tables
1. Actual numbers and expected numbers of tags recovered in four Bristol Bay fishing dis- tricts from sockeye salmon released in the Bering Sea and Bristol Bay by the United States and Japan in 1957, 1958, 1960, 1961, 1964, 1965 8 2. Summary of chi-square analysis of recovery data for tags released in the eastern Bering
Sea and outer Bristol Bay by the United States and Japan between 1957 and 1965 . 10 3. Total run (commercial catch plus escapement) of sockeye salmon (thousands offish) to four inshore fishing districts of Bristol Bay, 1955, 1956, 1957, and 1959, and ratio of each district's stocks to Naknek-Kvichak district stocks 18
Appendix Tables
1. Dates of exploratory fishing or tagging and source of data used to show the distribution and migration route of sockeye salmon in the offshore area of Bristol Bay 27 2. Number and percent of tagged sockeye salmon recovered in catch (commercial fishery) or observed in escapement from fish released at nine sites in Naknek-Kvichak and Egegik districts in 1955 28 3. Number and percent of tagged sockeye salmon recovered in catch (commercial fishery) or observed in escapement from fish released at 20 sites in Nushagak, Naknek-Kvichak, Egegik, and Ugashik districts in 1956 29 4. Number of tagged sockeye salmon recovered in catch (commercial fishery) from fish re- leased at two sites in Naknek-Kvichak fishing district in 1957 30 5. Number and percent of tagged sockeye salmon observed in escapement from fish released at two sites in Naknek-Kvichak fishing district in 1957 30 6. Number of tagged sockeye salmon recovered in catch (commercial fishery) from fish re- leased at four sites in Nushagak fishing district in 1959 31 7. Number and percent of tagged sockeye salmon observed in escapement from fish released at four sites in Nushagak fishing district in 1959 32
IV Migratory Routes of Adult Sockeye Salmon, Oncorhynchus nerka, in the Eastern Bering Sea and Bristol Bay
RICHARD R. STRATY-
ABSTRACT
The stocks of sockeye salmon, Oncorhynchus nerha, in Bristol Bay, Alaska, are produced in the lakes and streams of 10 major river systems, which discharge into the bay over a shoreline distance of 193 km. The establishment of fishing areas, the determination when fishing may be permitted, and the effect of exploiting simultaneously several stocks of sockeye salmon require knowledge of the migratory pattern of the individual stocks comprising the run to Bristol Bay during spaw- ning migration. Various mark-and-recapture experiments and exploratory fishing in the eastern Bering Sea and Bristol Bay provide a picture of the migratory pattern of Bristol Bay sockeye salmon from approximately long. I70°W to the head of Bristol Bay. The main migration route of all stocks of Bristol Bay sockeye salmon is in the offshore waters of the southern half of the entrance to the bay and in the southern half of the bay itself. All stocks remain in the offshore waters until within 32 to 80 km of their home-river systems. Segregation according to river of origin apparently began in the offshore waters as much as 200 km from the mouths of the home-river systems and appeared to progress to the head of Bristol Bay.
INTRODUCTION biologists have directed their efforts toward deter- mination of the routes and times of the spawning management in the Pacific Northwest has Salmon migrations of major stocks. These efforts have reveal- long been based on the premise that salmon homing to ed that most salmon stocks are completely separate various river systems or principal tributaries of river from others only when they become segregated in the systems constitute individual production units or spawning tributaries. stocks.' Because of its reproductive isolation and The establishment of fishing areas, the determina- attendant adaptive processes, each stock has its own tion of times when fishing may be permitted, and the requirements for spawning, incubation of eggs, unique assessment of the effects of exploiting simultaneously rearing, therefore be managed separate- and and must several salmon stocks having differing levels of ly insofar as it is practical to do so. productivity remain especially vexing problems. This of stocks of Pacific salmon, On- Thus, management is particularly true for the important stocks of sockeye corhynchus, in North America has resulted in a mul- salmon, 0. nerka, of Bristol Bay, Alaska where five tiplicity of regulatory districts, each of which is districts are designated for management and regula- associated with a major river, bay, or strait. Ideally, tion of the fishery—Togiak, Nushagak, Naknek- the times and places that salmon are taken would be Kvichak, Egegik, and Ugashik. The Togiak, Egegik, individual controlled within each district so that and Ugashik districts have single-river systems,^ stocks would be harvested independently of others, which discharge into Togiak, Egegik, and Ugashik in with its requirements each accordance own and Bays; the Nushagak district has four major river level of productivity. In pursuit of this ideal, fishery systems which discharge into Nushagak Bay; and the Naknek-Kvichak district has three river systems 'Based in part on a thesis submitted to the graduate school of discharge into (Fig. 1). Oregon State University, Corvallis, in partial fulfillment of the re- which Kvichak Bay quirements for the degree of Doctor of Philosophy, June 1969. Over the years the boundaries of each district have 'Northwest Fisheries Center, Auke Bay Laboratory, National undergone a number of changes which have generally Marine Fisheries Service. NOAA, Auke Bay, AK 99821. 'The term "stock" as used in this paper is applied to the popula- 'Each lake or group of connected lakes and its outlet to the ocean tion of salmon of a given species inhabiting a specific river system is termed a "system" and designated in this report by the name of or main tributary during the spawning and rearing stages of the life the outlet or trunk river. For example Coville, Grosvenor, Brooks, cycle. This use of the term is, for the most part, consistent with and Naknek lakes are connected to the ocean through the Naknek current management practices. River, and the system is therefore called the Naknek. Figure 1. —Principal sockeye salmon river systems in Bristol Bay. reduced the size of the area where fishing is permitted describe the probable routes followed by individual and have confined the fishing fleets closer to the river river stocks of sockeye salmon during spawning migra- mouths. The earliest changes were made on the large- tion from approximately long. 170° W in the Bering ly intuitive assumption that the fish nearest to a river Sea to the head of Bristol Bay. mouth were fish produced in that river system. To establish a more scientific basis for setting up THE SOCKEYE SALMON FISHERY district boundaries, mark-and-recovery experiments OF BRISTOL BAY which defined areas of concentrations of the major stocks of sockeye salmon were carried out in the inner Sockeye salmon runs to Bristol Bay are among the region of Bristol Bay in the 1950's and early 1960's by largest on the North American Continent. More than the Bureau of Commercial Fisheries (now the 50 million adult salmon have returned to spawn in the National Marine Fisheries Service, NOAA); the river and lake systems of this area in a single year. Fisheries Research Institute, University of The individual stocks that make up the annual run Washington, Seattle; and the State of Alaska Depart- are produced in the lakes and streams of 10 major ment of Fish and Game. The most extensive of these river systems which discharge into the bay over a were conducted from 1955 through 1959, principally shoreline distance of 193 km (Fig. 1). by the Bureau of Commercial Fisheries. In addition, a The spawning migration starts in the distant ocean considerable amount of salmon tagging and ex- in early May. Salmon move directly toward the Aleu- ploratory fishing has been carried out in outer Bristol tian Islands passes from their feeding grounds in the Bay and the eastern Bering Sea by the United States North Pacific Ocean and then eastward in the Bering and Japan. Sea to Bristol Bay at a rate of about 48 km per day In this study, I summarize the results of the inshore (Hartt 1962). Small numbers offish are on the fishing and offshore tagging and exploratory fishing and grounds by mid-June, and the run usually reaches peak proportions between 1 and 10 July. By late July involved in the exploratory fishing and the tagging I most of the fish have entered their respective river consider here are given in Appendix Table 1. systems, and few are left on the fishing grounds. Commercial fishing in Bristol Bay is done almost Exploratory Fishing. —The exploratory fishing entirely with gill nets. The nets are set from one- or was done in offshore waters of the Bering Sea inter- two-man boats and drift with the tide (drift nets) or mittently over a period of 28 yr. In most cases gill nets are staked or anchored along the beaches (set nets). of various lengths and mesh sizes were the principal The fishery is so intense and efficient that it takes gear, although purse seines and longlines were also almost all of the fish in a district during an open used. fishing period. Because of this, the fishery in each dis- Results from 8 of the years of this exploratory trict is closed periodically so that spawners from all fishing (all with gill nets) are used to show distribu- time segments of the run can escape to the stream. tion in the offshore area. These years were selected The day-to-day progress and size of the run through because (1) fishing was carried out during the period each fishing district is monitored by the Alaska of the spawning migration when sockeye salmon are Department of Fish and Game, which exercises con- most abundant (June and July); (2) fishing was fairly trol over Alaska fisheries. Test-fishing is done during systematic, usually on consecutive days at stations the closed periods and in closed fishing areas both up- located along given transects (Fig. 2); and (3) the stream and seaward of the fishery to obtain im- transects fished provided the most extensive coverage mediate indices of the numbers of fish entering and available. escaping the fishery. Finally, sample counts are made In some years fishing was carried out along a given from observation towers on each bank of all the major transect two or three times. In these instances, catch rivers entering the bay to obtain an accurate estimate data are used to examine the consistency of the of spawning escapements. sockeye salmon distribution and therefore the migra- tion route at various times during the spawning DETERMINING THE DISTRIBUTION migration. Fishing was also carried out along long. AND MIGRATORY PATTERNS OF 170°W in 3 different years, making possible a com- BRISTOL BAY SOCKEYE SALMON parison of sockeye salmon distribution between years with runs of different magnitude. Three different types of investigations have Fishing.—The gill net demonstrated that sockeye salmon in the Bering Sea Results of Exploratory catches of sockeye salmon along the six transects es- near long. 170°W and lat. 60°N are bound for Bristol tablished across the approaches to Bristol Bay in the Bay. These investigations involved (1) studies of scale of sockeye characters, morphological characteristics, and offshore area show that the abundance increases and then decreases with increasing parasite infestations (Margolis et al. 1966); (2) studies salmon northerly direction offshore from the of the direction of movement of sockeye salmon distance in a northwestern side of the Alaska Peninsula and the caught in gill nets (Barnaby 1952) and purse seines northeastern Aleutian Islands (Figs. 3-10). With one (Hartt 1962); and (3) tagging experiments (Hartt exception (28 June-3 July 1940— Fig. 6) this pattern 1962, 1966; Kondo et al. 1965). was consistent for all years and along all of the In this section I examine data from these published sources and from unpublished tagging studies done in transects. of greatest abundance of sockeye salmon Bristol Bay proper to describe the distribution and The area transect was between 161 and migration pattern of stocks in offshore and inshore along the long. 170°W 322 offshore in 1958, 1959, and 1961 (Figs. 3-5). areas. In addition, I use changes in the age group km nearer the south side of the Pribilof structure of fish tagged at various locations to show Catches decreased 1961 large catches were made the distribution of several major sockeye stocks in the Islands. In 1959 and Islands (Figs. 4 and but they inshore area. The offshore region includes that area of north of the Pribilof 5), with increasing distance to the north of the Bering Sea east of long. 170°W and south of lat. decreased these islands. comparison of the abundance of fish 60° N to a line drawn between Cape Constantine and A along the long. 170°W transect at approximately the the Cinder River (Figs. 1 and 2). The inshore area in- week or two apart, shows that cludes the remaining area to the river mouths. same locations, but a the pattern of distribution remained essentially the Offshore Distribution same (Fig. 5). This 2-wk period is sufficient for the major portion of the total Bristol Bay sockeye salmon The distribution and migration routes of sockeye run to pass through this area. These results, plus the salmon in the offshore area have been determined fact that the distributions of sockeye salmon in the 3 from the results of exploratory fishing along north- yr were similar, suggest that this pattern may not vary south transects by research vessels of the United greatly during the time the entire run passes through States and from the locations of recapture of sockeye this area or from year to year. salmon tagged in the offshore area by the United Along the transect between Cape Mordvinof and States and Japan. The sources of data and the years the Pribilof Islands the size of the catches increased, 60'
59'
58'
ST. PAUL 57'
56'
55=
54'*- 700- 400-
1 JUNE 27 — NUNIVAK ISLAND O 300- iJUNE 21 O I I500- (/) JUNE 28
"400- jST PAUL ISLAND JUNE 29 4 ST. GEORGE ISLAND JUNE 19 UJ |300- JUNE 30 2 o 100- JUNE 18
"JUNE 17 _L -L. -L. -L. _L I JULY 2 20 40 60 80 100 120 140 160 ISO
' JULY 3 15 NUMBER OF FISH/1,250 FATHOMS OF NET
_l I 20 40 60 80 100 120 140 160 180 200 Figure 7. —Gill net catches of sockeye salmon between Pribilof NUMBER OF FISH/36 SHACKLES OF NET/ 12 HR FISHING Islands and Nunivak Island, 17-21 June 1940. Note: Fishing time was not specified, but I assumed that it was the same for Figure 4. —Gill net catches of sockeye salmon along approxi- each set. (See Appendix Table 1 for source of data.) mately long. 170°W, 27 June-3 July 1959. Each shackle of net
was about 50 fathoms. (See Appendix Table 1 for source of data.)
600-
400- 'ST. PAUL ISLAND
< ST GEORGE ISLAND JUNE 2! u) 300- ^—— JUNE 16
JUNE 22 2 200-
I JUNE 23
I JUNE 24 I JUNE 12 ^^JUNE 25
I I I 1_ .J_ -L. l_ 40 80 120 160 200 240 40 60 80 120 160 (JUNE 12-18) (JUNE 19-25)
NUMBER OF FISH /40 SHACKLES OF NET/ I 2 HR FISHING
Figure 5.— Gill net catches of sockeye salmon along approxi- mately long. 170°W, 12-25 June 1961. Each shackle of net was about 50 fathoms. Note: The net was fished for only 7 h on 21 June; the net used on 25 June had only 39 shackles. (See Appen-
dix Table 1 for source of data.)
— ST RIUL ISLAND m JUNE 16 JULY 3 — ST GEORGE ISLAND NO FISH JUNE 16 ^" JULY 2 JUNE 9
I JUNE 29 JUNE 28 -NO FISH JUNE 789 -NpFIS^ }JUf Figure 6. —Gill net catches of sockeye salmon between Cape Mordvinof and Pribilof Islands, G June-3 July 1940. Note: Fish- ing time was not specified, but I assumed that it was the same for each set. (See Appendix Table 1 for source of data.) 15 30 45 60 75 90 NUMBER OF FlSH/50 FATHOMS OF NET / I 2 HR FISHING Figure 9. —Gill net catches of sockeye salmon along approxi- mately long. 161°30 W, 24 June-6 July 1965 and 1966. (See Ap- pendix Table 1 for source of data.) that shown by catches along the transect between Cape Seniavin and Cape Newenham in 1939 (Fig. 10). Here, the distribution remains essentially the same from early to late July. The greatest abundance of sockeye salmon along both transects was offshore but in the southern half of Bristol Bay. The pattern of abundance of sockeye salmon in gill nets fished by the Japanese training ship Oshoro Maru in 1967 and 1969 (Hokkaido University, The Faculty of Fisheries 1968, 1970) in the western part of Bristol Bay substantiated their high abundance in this region during the spawn- ing migration. The abundance of sockeye salmon along all transects was greatest in offshore waters of the eastern Bering Sea and in Bristol Bay itself. 240- 60' 59" - 58" - 57* 56" - 55" - Figure 11. —Distribution of sockeye salmon in eastern Bering Sea and Bristol Bay during spawning migration, showing main migration route. Distribution was determined from results of exploratory fishing. River sockeye salmon, Peterson (1954) showed that «.-(l)'^.) gill nets of the type and mesh size (13.65-cm stretch measure) used in Bristol Bay were selective for size of where fish. Differences in the size composition between the R^ = expected number of tag recoveries from the commercial catch and the escapement indicate that ith fishing district the gill nets used by Bristol Bay fishermen are selec- R = tag recoveries in total Bristol Bay commer- tive for the larger .3 fish' (Mathisen 1971). Apparent- cial catch ly, many of the smaller .2 fish are able to pass through C = total Bristol Bay commercial catch the gill nets and escape. Cj = catch in the ith fishing district. Ricker (1958) found that fish tagged with plastic For most years, the recoveries from several tagging disk tags, the type used most frequently in the locations have been grouped for computation of ex- offshore tagging studies, are more vulnerable to cap- pected recoveries (Table 1). This was done because ture by gill nets than untagged fish because the twine tagging was often carried out in the same general area of the net catches under the disk. Because of the tag, a or to provide a larger number of recoveries in the analysis. 'The terms .2 and .3 refer to the number of winters a salmon has Several factors inherent in the commercial fishery spent in the ocean. A numeral to the left of the dot indicates the could cause the smaller tagged fish to be more number of winters the fish has spent in fresh water and the numeral to the right of the dot the number of winters in the ocean. Thus a 2.3 vulnerable to capture than untagged fish of the same adult salmon is one which has spent 2 winters in fresh water and 3 size. winters in the ocean and is in its sixth year of life. The use of this Commercial fishing in all districts of Bristol Bay is method (European method) for designating the age of adult Pacific done entirely with gill nets. Working with Fraser salmon (marine life only) was proposed by Koo (1962). Table 1.- -Actual numbers and expected numbers {in parentheses)- of tags recovered Table 1 .--Conti nued. in four Bristol Bay fishing districts from sockeye salmon released (see Fig. 12 for tagging sites) in the Bering Sea and Bristol Bay by the United States and Japan in 1957, 1958. 1960, 1961, 1964, 1965. (See Appendix Table 1 for sources of data.) Recoveries by fishing district Year, country, '^' East side and tagg ing site —^^ Date of Naknek- A T~\ \ (lat. and long.) tagging Nushagak Kvichak Eqegik 1957— United States Midway between Unalaska Island and Pribi lof Islands 17 June 55^37'N. 168°33'W 56''00'N. 170°00'W 56°12'N. 169°54"W 56°50'N. 170°13'W Se^lO'N, 171*08'W 54°2rN, 166°55'W Total 1958-United States 170' NUNIVAKI 59° - • 1957 U.S O 1958 U.S n I960U.S A I9 60 JAPAN 58' A 1961 JAPAN ® 1964 U.S. 'P/. % O 1965 U.S. ST, PAUL I 57°- 0©^^ © ©9^ ST GEORGE I. 56' 55' A^ CAPE MORDVlNOF^.v'-^'^W>^-^o 54' 9?' ^^/ UNALASKA I Jd. 170' 165' 160* Figure 12. -Areas of tagging by United States and Japan in the 6 yr selected for study to determine tlie distribution of sockeye salmon stocks in offshore area of Bristol Bay. (See Appendix Table 1 for source of data.) greater proportion of the .2 fish, which were better between the actual and expected number of tags able to pass through the gill nets, might be captured; recovered in the four Bristol Bay fishing districts .3 fish were usually held in the net by the gills. (Table 1), are the results of the only significant tag- The size composition of sockeye salmon runs to ging to be carried out in the Bering Sea and outer each fishing district in Bristol Bay varies from year to Bristol Bay. Therefore, I have used consistencies in year and between districts in a single year. In some the recovery distribution for all 6 yr of tagging as an years the run to a given district may be composed indication of segregation of individual sockeye stocks largely of the smaller .2 fish. In other years the larger in the offshore area. The results of the chi-square .3 fish may predominate. Large differences between analysis to test the hypothesis of like distribution in districts in the proportion of .2 and .3 fish could lead the offshore area for all sockeye salmon stocks of to error in interpreting tagging results because of the Bristol Bay origin are given in Table 2. differences in the vulnerability of tagged fish in these Except for 1958, the hypothesis of like distribution, two size groups. No adjustments have been made for i.e., no segregation, for all sockeye salmon stocks of the selective action of gill nets in calculating the ex- Bristol Bay origin occurring in the eastern Bering Sea pected number of tags from each district, and the is not rejected. A consistent feature in the recovery assumption is made in the analysis that tagged fish in data for those sockeye salmon tagged in the Bering both size groups were as vulnerable to fishing as un- Sea in 1957, 1958, 1960, 1961, and 1964 (tagging sites tagged fish. 8, 9, and 10, Fig. 12) is the lower-than-expected number of recoveries in the Nushagak fishing district Results of Tagging. —The tag recoveries, though (Table 1). However, except for the 1958 tagging near few in number and producing only small differences the Pribilof Islands, differences between the actual ) and expected numbers of tag recoveries were not large Although the data are weak because of the few tags enough to result in significant chi-squares in tests recovered from taggings at stations 12, 13, 15, and 16, between sockeye salmon stocks from individual the distribution of the tag recoveries suggests that fishing districts or between members of stocks cap- segregation of individual stocks may be beginning in tured in fishing districts on the east and west sides of this region of Bristol Bay. For example, recoveries in Bristol Bay (Table 2). The significant chi-square ob- the Egegik and Ugashik districts (Table 1) were about tained in the analysis of the 1958 tag recovery data equal to or were greater than the expected number was largely due to the few Nushagak recoveries and to from the tagging at station 12 (inshore), but no a lesser extent the more-than-expected Egegik recoveries were made from the offshore tagging at sta- recoveries (Table 1). The few tags recovered from the tion 13 (offshore). Also recoveries from the Naknek- taggings at sites near the Pribilof Islands in 1964 (sites Kvichak district were less than expected from fish 8 and 9, Fig. 12) did not result in significant chi- tagged at station 12 but about as expected from fish squares and is in contrast to the results of the 1958 tagged at station 13. Recoveries from Nushagak Bay tagging in the same area. were about as expected from tagging at station 12 and Tagging in outer Bristol Bay in 1964 at stations 12, greater than expected from tagging at station 13. 13, 15, and 16 (Fig. 12) was closer to the mouths of the My interpretation of the data from the outer two major river systems, where one might expect more stations is as follows: Ugashik and Egegik fish are pres- segregation of individual stocks. Tagging stations 12 ent at station 12 nearshore but not at station 13 and 15 were near shore, and stations 13 and 16 were offshore, an indication that these stocks are beginning well offshore. For these reasons tag recoveries from to leave the offshore waters and move toward their each of the four stations were treated individually and home-river systems on the east side of Bristol Bay. then combined as nearshore and offshore tagging This would decrease the proportion of Naknek- (Table 1). In all tests the differences between the ac- Kvichak stocks at station 12 near shore. The number tual and the expected number of tag recoveries were of Naknek-Kvichak recoveries from tagging at station not sufficient to result in significant values of chi- 12 was, in fact, less than expected (Table 1). The ac- square (Table 2), and the hypothesis of like distribu- tual number of Naknek-Kvichak recoveries from sta- tion for all sockeye salmon stocks is not rejected. tion 13 is close to the expected number and indicates Table 2. --Summary of chi-square analysis of recovery data for tags released in the eastern Bering Sea and outer Bristol Bay by the United States and Japan between 1957 and 1965. (See Fig. 12 for location of release sites. that stocks of sockeye salmon bound for these river tagging sites toward the west side of the bay than at systems are still abundant in the offshore waters. the inshore sites toward the east side. Although the differences are slight, the recovery data The distribution of the recoveries from fish tagged indicate that Nushagak Bay stocks are more abun- at lat. 57°48'N and long. 158°30'W (near Cape Greig, dant offshore (station 13) than inshore (station 12). the most easterly of the offshore tagging sites) differs Tagging stations 15 and 16 are closer to the head of from the distribution of recoveries from fish tagged Bristol Bay (Fig. 12), and Ugashik and Egegik more seaward in 1965 (Table 1). Significant chi- recoveries from station 15 (nearer shore) were sub- squares were obtained for comparisons both between stantially greater than expected (Table 1). Ugashik individual fishing districts and between east and west and Egegik recoveries from station 16 (offshore), on side districts (Table 2), and are cause for rejection of the other hand, were almost lacking. This is the same the hypothesis of like distribution for all stocks in the pattern that resulted from taggings at stations 12 and area of tagging. The high chi-square values are due to 13 farther seaward. Likewise the returns of Naknek- the much greater-than-expected number of recoveries Kvichak and Nushagak stocks tagged at stations 15 from the Nushagak Bay district and the substantially and 16 are like those of taggings at stations 12 and 13, smaller-than-expected number of recoveries from the i.e., these stocks are still mostly offshore (station 16) Naknek-Kvichak district. This distribution of rather than inshore (station 15). recoveries suggests that stock segregation is occurring Finally, comparisons of the tag recoveries from the toward the head of the bay, and appears consistent east districts (Naknek-Kvichak, Egegik, and Ugashik with the results farther offshore. The Cape Greig tag- combined) with those from the west district ging site (lat. 57°48'N and long. 158°30'W) is offshore (Nushagak) further suggest that segregation of stocks and comparable to sites 13 and 16—Fig. 12). My inter- is taking place as the fish progress toward the inner pretation of this pattern is that by the time migrating bay. The recoveries from nearshore taggings (stations salmon have progressed this far up the bay, most of 12 and 15) in the combined three east districts and the the Egegik and Ugashik fish have gone inshore, as single west district were near the expected number have many fish of the Naknek-Kvichak stocks, and (Table 1). Recoveries from the offshore taggings many of the remaining offshore fish are bound for the (stations 13 and 16) were greater than the number ex- Nushagak district. pected in the Nushagak district (west side) and less than the number expected in the combined east side Synopsis: Segregation of Sockeye Salmon Stocks districts (Table 1). These differences, however, were in the Eastern Bering Sea and Outer Bristol not great enough to result in rejection of the Bay. —The distribution of recoveries of sockeye hypothesis of like distributions for sockeye salmon salmon tagged in the offshore area between long. 165° stocks destined for fishing districts on each side of and 170°W and south of lat. 57°N (Fig. 12) were con- Bristol Bay. sistent in showing that fish bound for the four major All the tagging in 1965 was done within Bristol Bay fishing districts were present in the tagging area in in three general areas: (1) lat. 57°N and long. 160°W proportion to their abundance in the total run to (most seaward); (2) lat. 57°48'N and long. 158°30'W Bristol Bay. In only one instance (1958) was the (nearest the head of the bay); and (3) opposite Port hypothesis of like offshore distributions for all stocks Heiden—actually seven closely adjacent locations rejected. In most cases, the results also showed that midway between areas one and two (Fig. 12, Table 1). stocks of sockeye salmon bound for the Nushagak Again, the results of chi-square tests of the recovery fishing district occurred at tagging locations in distributions from the taggings at lat. 57°N and long. numbers less than expected. Although exploratory 160°W and from the taggings opposite Port Heiden fishing has shown substantial numbers of sockeye (Table 2) did not result in rejection of the hypothesis salmon occur north of lat. 57°N, only limited tagging of like distributions of all stocks. Recoveries in the was carried out in this area and too few tags were Nushagak district were less than expected, but recovered to make an analysis. recoveries in the Naknek-Kvichak district occurred in The recoveries from the tagging at sites inside about the numbers expected. Recoveries in the Egegik Bristol Bay (between long. 158° and 161°W—Fig. 12) district were about as expected from tagging at lat. showed that Nushagak district stocks were present in 57°N and long. 160°W but were considerably more expected or greater-than-expected numbers at the abundant than expected from the seven grouped northernmost tagging sites. Sockeye salmon bound for taggings. Differences from the expected number of the Nushagak district may also be more abundant recoveries in the Ugashik district were not great. A than expected in the eastern Bering Sea. Apparently, comparison between east and west side fishing dis- the more northerly portion of the area encompasses tricts shows that recoveries from the west side their migration route, but data to substantiate this (Nushagak Bay) were fewer than expected. These point are lacking. For the present, the stock composi- results and those from the 1964 taggings farther tion of sockeye salmon in the northern portion of the offshore (stations 13 and 16 in Table 1) indicate that approach to Bristol Bay remains open to question. sockeye salmon stocks bound for the Nushagak dis- The recoveries of sockeye salmon tagged between trict (west side) were more abundant at the offshore long. 158° and 161 °W showed an increase in the 11 segregation of stocks toward the head of the bay. Fish net fishery, and the spawning grounds. The visual bound for the Nushagak and Naknek-Kvichak fishing sightings were made either from weirs built across districts were still abundant in the offshore tagging some of the major rivers or from towers located on areas toward the head of the bay. Those bound for the each bank of the other rivers. Observations were made Ugashik and Egegik districts, however, were less from these structures of tagged fish in the daily es- abundant at offshore locations and apparently had capement to each major river system. Placards dis- already moved toward the coast and the mouths of playing tag color combinations were placed at the their home-river systems. counting gates of each weir and at each tower to facilitate positive identification of tagged salmon. Inshore Distribution Analysis of Recovery Data. —I used the tag The distribution of individual sockeye salmon recoveries from the Nushagak, Naknek-Kvichak, stocks in the inshore area of Bristol Bay was deter- Egegik, and Ugashik fishing districts and the obser- mined from unpublished data from tagging ex- vations of the tags sighted in the escapements to the periments and related studies I conducted in inner individual river systems to show the distribution in Bristol Bay in 1955-57 and 1959. The tagging sites inner Bristol Bay of the stocks of sockeye salmon were located within and adjacent to the four bound for the four river systems. In addition, the regulatory fishing districts in the inshore area: fishery recoveries from the 1959 tagging in Nushagak Nushagak, Naknek-Kvichak, Egegik, and Ugashik. Bay were grouped according to location of capture Tagged fish were recovered by the commercial fishery within the Nushagak district. For this purpose the within these districts. Some tagged fish were seen at district was divided into five subdistricts, and the dis- weirs or from towers located on the major river tribution of fish from each tagging site within these systems entering each fishing district. Tagging was subdistricts was used to show the distribution of each not carried out in all of the districts during the 4 yr of stock contributing to the total run to the Nushagak the study; the schedule was as follows: district. 1955— Naknek-Kvichak and Egegik (Fig. 13); Because the commercial catch of sockeye salmon 1956— all four districts (Figs. 14 and 15); within the four fishing districts is composed of mixed 1957 — Naknek-Kvichak (Fig. 16); and stocks, the distribution of tagged fish in the escape- 1959—Nushagak (Fig. 17). ment is a better indicator of the final destination of Unfortunately, no sockeye salmon were tagged in a fish released at various sites in inner Bristol Bay than large area in the middle of the inner bay, and in the distribution of tagged fish caught in the fishing analyzing the tag recovery data I therefore infer the districts. Fish recaptured in the fishing districts have stock composition of fish in that region from the been included in the analysis, however, because they results of both the offshore and inshore tagging. serve to complement the results shown by the dis- One additional method was used to show the dis- tribution of tags in the escapement. When viewed tribution of sockeye salmon stocks in 1955. The age with the distribution of tags in the escapement, the group (2.3, 1.3, 1.2, etc.) of each fish tagged at seven distribution of tags in the fishing districts aids in in- sites in the Naknek-Kvichak and Egegik fishing dis- terpreting the movement of individual sockeye tricts (Fig. 13) was determined from scale readings. I salmon stocks within these districts. In addition, both used the age group structure of the fish tagged at each types of tag recovery distributions indicate that the site to aid in explaining the distribution of Naknek- mixing of several nondistrict stocks within a given Kvichak and Egegik River sockeye salmon stocks in fishing district was not serious enough to prevent in- the inshore area. terpretation of the distribution and migration routes of individual sockeye salmon stocks in inner Bristol Capturing and Tagging Fish and Recovery of Bay. Tags. —The sockeye salmon for tagging were cap- I made several assumptions in interpreting the tag tured in linen or nylon drift gill nets of the type (13.97- recovery data: First, sockeye salmon of each river cm stretch measure, 28 meshes deep) commonly used system are assumed to be tagged in proportion to their in the Bristol Bay commercial fishery during the years abundance in the area of tagging. If significant mixing of tagging. of stocks of two different ocean age groups ( .2 or .3) oc- Fish were marked with serially numbered red, blue, curred in that area of tagging, the selective action of green, white, and yellow Petersen disk tags used in the gill nets (page 7) used to capture fish for tagging various color combinations so that the date and loca- could have resulted in a larger proportion of one stock tion of tagging could be determined from visual obser- being caught and tagged than were actually present. vations. In general, the recovery distributions resulting from Recoveries of tags in the 4 yr of the study included tagging at several of the same locations but in actual recaptures and visual sightings of tagged fish. different years were similar. The magnitude of the run Actual recaptures were obtained from the commercial as well as the size composition varied between fishing gill net fishery operated in each district, the personal- districts in these years. The similarity of distributions use gill nets operated on the major rivers above the gill for different years indicates that such mixing of stocks 12 r TAGGING SITES BOUNDARIES OF DISTRICTS OPEN TO FISHING FISHING DISTRICT TAG RECOVERIES ^;77A ESCAPEMENT TAG OBSERVATIONS 156° \—r— Figure 13. — Distribution of tags recovered in catch (commercial fishery) and observed in the escapements from sockeye salmon released at nine tagging sites in Naknek-Kvichak and Egegik fishing districts (inshore area) in 1955. 13 W TAGGING SITES BOUNDARIES OF DISTRICTS ~ ~ OPEN TO FISHING FISHING DISTRICT TAG RECOVERIES \yy/^ ESCAPEMENT TAG OBSERVATIONS RECOVERY AREA Figure 14. — Distribution of tags recovered in catch (commercial fishery) and observed in the escapements from sockeye salmon released at 10 tagging sites in Nushagak and Naknek-Kvichak districts (inshore area) in 1956. of different ocean age was not serious enough to pre- intensity. Therefore, I consider the apparent distribu- vent interpretation of the distribution of individual tion of individual sockeye salmon stocks in inner stocks in inner Bristol Bay. Bristol Bay resulting from my analysis to represent A second assumption is that the proportion of each the major portion of the run to each district. stock at a given tagging location remained essentially A third assumption made in analyzing the tagging the same throughout the duration of the sockeye data is that tagged fish recaptured in each district had salmon run into Bristol Bay. This assumption is an equal likelihood of being reported to investigators. necessary because I have grouped the recoveries from There was no reason to expect a variation in reports all laggings at each site (regardless of the date when from fishermen in each district of the tagged fish cap- the fish were tagged) so that I would have enough tags tured and therefore no reason to question the validity for analysis, particularly in 1955, 1956, and 1959. of this assumption. In most years and at most tagging sites, fish were The final assumption is that each tagged fish in the tagged during the 2-wk period when sockeye salmon escapement had an equal likelihood of being obser\'ed runs to each fishing district reached their maximum and identified as to its location of tagging. It was 14 9 TAGGING SITES BOUNDARIES OF DISTRICTS OPEN TO FISHING ^Hl FISHING DISTRICT TAG RECOVERIES ^///A ESCAPEMENT TAG OBSERVATIONS RECOVERY AREA Figure 15. —Distribution of tags recovered in catch (commercial fishery) and observed in the escapements from sockeye salmon released at 10 tagging sites in Naknek-Kvichak, Egegik, and Ugashik fishing districts (inshore area) in 1956. 15 necessary to ascertain the color of the tag on each side actual number of tags in the spawning escapement to of the fish to determine where the fish had been tag- rivers where tags were observed from towers was ged. At the weirs this was a relatively simple task, probably higher than is shown in the results. because the observer sat directly over an opening through which each fish had to pass and both sides of Interpretation of Tagging Results. —Recoveries the fish could be seen easily. Identifying the color of and visual observations of the tagged fish released at the tag on both sides of a fish from a tower was more sites within and adjacent to the four regulatory fishing difficult, however. The observer did not sit directly districts in the inshore area in 1955, 1956, 1957, and over the fish as they moved upstream, and if the fish 1959 (Figs. 13-17) are used in this section to show the were some distance from shore, the observer could distribution of major sockeye salmon stocks. The identify the color of the tag on only one side. number of tagged fish recovered in the commercial Therefore, rivers with weirs probably had a higher fishery in the inshore area and those observed in the proportion of tagged fish identified correctly than did escapement at weirs, towers, or on the spawning rivers covered by towers. Because of such factors as grounds on the five major sockeye salmon river the magnitude of the run and turbidity of the water, systems of Bristol Bay are listed in Appendix Tables the ability to identify tagged fish from towers also 2-7. varied from day to day, between river systems, and The relative sizes of the runs (catch plus escape- from year to year. The numbers of fish bearing each ment) to each of the inshore fishing districts in the 4 tag color combination observed in the spawning es- study years (Table 3) must be taken into account capement to each river system have not been adjusted when drawing inferences about the distribution of for possible differences in the ability of observers to each major sockeye stock from the distribution of identify the color of both tags. When viewing the tagged fish because the size of the runs to each district recovery distribution in the discussion of the tagging varies from year to year. Tag recoveries have not been results, the reader should keep this point in mind. The weighted for size of run because, as will become ap- TAGGING SITES BOUNDARIES OF DISTRICT OPEN TO FISHING FISHING DISTRICT TAG RECOVERIES ESCAPEMENT TAG OBSERVATIONS 157° RECOVERY AREA Figure 16. —Distribution of tags recovered in catch (commercial fishery) and observed in the escapements from sockeye salmon released at two tagging sites in Naknek-Kvichak fishing districts (inshore area) in 1957. 16 parent in the discussion below, the recorded catch for action of the gill nets (see page 7). The mixing of each district was composed of stocks destined for the stocks within fishing districts, however, was not con- river systems of several fishing districts. The con- sidered serious enough to prevent use of the size of the tribution of each stock to the commercial catch of a total run in interpreting the distribution of tagged fish fishing district will vary from year to year depending for the 4 yr of study. In most years large escapements on the relative size of the individual runs. Assignment to individual rivers occurred when large catches were of portions of the catch in each fishing district to in- made within the fishing district (Table 3). dividual river systems was not done in 1955 and 1956, but it was done in 1957 and 1959. These appor- Distribution of Sockeye Salmon Stocks Oc- tionments were based on the age composition of the curring on the East and West Side of Inner Bristol spawning escapement of each river system. The age Bay. —The distribution of tags recovered in the com- composition of the escapement, however, has been mercial fishery and observed in the spawning escape- modified to a certain extent because of the selective ment (Figs. 13-17) showed that sockeye salmon stocks 9 TAGGING SITES BOUNDARIES OF DISTRICT OPEN TO FISHING WM FISHING DISTRICT TAG RECOVERIES P?^ ESCAPEMENT TAG OBSERVATIONS 159° 158° RECOVERY AREA Figure 17.—Distribution of tags recovered in catch (commercial fishery) and observed in the escapements from sockeye salmon released at four tagging sites in Nushagak fishing district (inshore area) in 1959. 17 Table 3. --Total run (cofmercial catch plus escapement) of sockeye salmon (thousands of fish) to four inshore fishing districts of Bristol Bay, 1955, 1956. 1957, and 1959,- and ratio of each district's stocks to Naknek-Kvichak district stocks. Item 1955 1956 1957 Naknek-Kvichak district Catch 2,564 4,579 1.689 Escapement Kvichak River 250 Alagnak River Naknek River Total run Nushagak district Catch Escapement Wood River Igushik River Nushagak River Snake River Total run Ratio to Naknek-Kvichak stocks Egegik district Catch Escapement Total run Ratio to Naknek-Kvichak stocks Ugashik district Catch Escapement Total run Ratio to Naknek-Kvichak stocks TAGGING SITES BOUNDARIES OF DISTRICT OPEN TO FISHING BB 1956 ^ 1959 9 TAGGING SITES OF DISTRICT BOUNDARIES oc OPEN TO FISHING ^H 1955 TAGGING VZ^ (956 TAGGING 158° the smaller runs of sockeye salmon to the Naknek and vations of fish tagged on the west side of the bay were Kvichak Rivers in 1955 than in 1956 and 1957 (Table made in the Kvichak River system but a few were 3), so that a greater proportion offish of Egegik origin made in the Naknek River system. The results were were probably taken in the Naknek-Kvichak fishing similar for sockeye salmon tagged at site 1 on the west district in 1955 than in 1956 or 1957. side of Kvichak Bay in 1957 (Fig. 16). Fishery recoveries and escapement observations of The escapement distribution of fish tagged on the sockeye salmon tagged between Middle Bluff and the east side of Kvichak Bay between the Naknek River entrance to Egegik Bay showed that Egegik River fish mouth and the outer boundary of the Naknek- were the most abundant stock in this area (Figs. 13 Kvichak fishing district indicated that a mixture of and 15). The runs of Naknek and Kvichak River fish Naknek, Kvichak, and Egegik stocks occurred there outnumbered Egegik fish in all years of tagging, but (Figs. 13-15). More fish from these taggings were probably were offshore and outside this tagging area. observed in the Naknek River system than in the The recoveries of sockeye salmon tagged at the outer Kvichak River system in 1955 (Fig. 19), indicating a east side boundary of the Naknek-Kvichak fishing greater abundance of Naknek fish in the area of tag- district, however, showed that Naknek and Kvichak ging. River fish became the most abundant stocks in the This dominance of Naknek River sockeye salmon in nearshore area north of Middle Bluff. Most Egegik the area of tagging is also reflected in the age composi- River fish apparently left the offshore waters for the tion of fish tagged at sites 1 through 7 in 1955 (Fig. coast and their home-river system south of the outer 20). The age composition of sockeye salmon in the es- boundary of the Naknek-Kvichak fishing district. capements to the Naknek, Kvichak, and Egegik The recoveries of sockeye salmon tagged south of Rivers differed significantly in 1955. These differences the entrance to Egegik Bay in 1956 (Fig. 15) showed are discussed here as supporting evidence for my in- that Egegik fish were abundant in the coastal areas as terpretation of the distributions of Naknek, Kvichak, far south as the entrance to Ugashik Bay. Egegik and Egegik stocks based on the results of inshore tag- River sockeye salmon were probably the most abun- ging. The dominant age groups in the escapements dant stock north of site 15 (Fig. 15), while Ugashik were: 2.3 in the Egegik River, 1.3 in the Naknek River River fish, as pointed out above, were the most abun- (Fig. 20), and 1.2 in the Kvichak River. The propor- dant in the area between tagging sites 18 and 16. Most tion of the 2.3 and 1.3 age groups at each tagging site fish bound for the Naknek, Kvichak, and Alagnak changed between the mouth of the Egegik and rivers were apparently farther offshore outside the Naknek Rivers (Fig. 20). The 2.3 age group decreased area of tagging. in abundance north of the Egegik River mouth, and the 1.3 age group increased in abundance. This show- Distribution of Naknek and Kvichak River ed a change from the Egegik River stock to Sockeye Salmon in Inner Bristol Bay, —Sockeye predominantly Naknek River stock, consistent with salmon tagged as far south as the entrance to Ugashik the results of tagging discussed above. Bay on the east side of inner Bristol Bay were recovered in the Naknek-Kvichak fishing district and River escapement (Fig. 15). observed in the Kvichak NAKNEK Sockeye salmon tagged on the west side of Kvichak Bay (Fig. 16) and in outer Nushagak Bay off Etolin Point (Fig. 14) were recovered in the Naknek-Kvichak N = 548 fishing district and observed in the Kvichak River es- capement. The results of the taggings discussed thus O JI 1 far, however, have shown that the main migration ESCiPEMENT route of sockeye salmon bound for the Naknek and Kvichak River systems was offshore outside the area of tagging on both the east and west sides of inner Bristol Bay. Naknek and Kvichak River sockeye salmon stocks become abundant in the coastal waters only north of Middle Bluff on the east side and northeast of Etolin Point on the west side of Kvichak Bay. In this region, Kvichak Bay is only about 32.3 km wide and Naknek, Kvichak, and Alagnak River stocks probably occupy the entire area during the migration to their home-river systems. The escapement recoveries of fish tagged in 1955 and 1956 at the same locations on the east and west sides of Kvichak Bay (Fig. 19) indicates that sockeye salmon on the west side of the bay were largely Kvichak River stocks. Most of the escapement obser- With the exception of the tagging off the Naknek also indicated by the fishery recoveries of fish tagged River mouth, more fish from the 1956 taggings along at sites 1-4 in 1959. The tags recovered within the the east side of Kvichak Bay (Figs. 14 and 15) were Nushagak fishing district were grouped by tagging observed in the Kvichak River escapement than in the site and subdistrict in which they were recovered (Fig. Naknek River escapement. In 1956 the escapement to 21). A high proportion of the fish tagged at sites 1 and the Kvichak River system was more than five times 2 were caught in a subdistrict encompassing the that to the Naknek River system (Table 3). This Igushik River mouth; most of these fish were recap- greater abundance of Kvichak River sockeye salmon tured in the set and drift gill nets operated within or would explain why more Kvichak River fish than close to the Igushik River mouth. Most of the recap- Naknek River fish were tagged on the east side of tures of sockeye salmon tagged at sites 3 and 4 were Kvichak Bay. Naknek stocks, however, were still from subdistricts on the east side of Nushagak Bay. more abundant on the east side than on the west side As shown above, more sockeye salmon tagged at sites of Kvichak Bay in 1956. 3 and 4 were observed in the Wood River escapement The escapement distribution of sockeye salmon than in the escapement to the other river systems, in- tagged at site 2 on the east side of Kvichak Bay in dicating that the Wood River stock moved through 1957 (Fig. 16) showed that Naknek River fish were Nushagak Bay principally on the east side. more abundant than Kvichak River fish in this area. In spite of the dominance of Wood River stocks in Although the run to the Naknek-Kvichak fishing dis- 1959 and the smaller amount of fishing effort on the trict in 1957 was about half as large as in 1956, the west side of Nushagak Bay, most of the fish that were relative sizes of the escapements to the Naknek and tagged at site 1 and recaptured were recaptured on the Kvichak Rivers (Table 3) indicated that Kvichak west side of Nushagak Bay. Wood River stocks River stocks again dominated this run. Kvichak River generally make up the greater portion of the total run fish were apparently not as abundant in the near- to Nushagak Bay. For example, in 1959 the Wood shore waters on the east side of Kvichak Bay in 1957 River escapement was more than three times the as they were in 1956; as a result, a higher proportion of Igushik escapement (Table 3), and over 75% of the Naknek fish were probably tagged in this area in 1957. fishing effort in 1959 (estimated from aerial surveys of The foregoing results illustrate three points about the fishery) was concentrated in the eastern half of | the distribution of sockeye salmon stocks in Kvichak Nushagak Bay, which is the area of greatest fishing Bay. First, Kvichak and Wood River stocks occurred success. The proportion of tagged fish observed in the together along the west side of Kvichak Bay between escapement was significantly higher for fish from site Etolin Point and the outer boundary of the Naknek- 1 than for fish from the other three sites (Appendix Kvichak fishing district. Second, a mixture of Table 7), and probably reflects the smaller amount of primarily Naknek and Egegik River stocks occurred fishing effort on the west side of Nushagak Bay. along the east side of Kvichak Bay. Third, the stock The escapement distribution of sockeye salmon composition changed from principally Naknek River tagged off Etolin Point in 1956 was similar to that of sockeye salmon on the east side of the bay to mainly the fish tagged in this location in 1959 (Fig. 18), which Kvichak River sockeye salmon on the west side. suggests that sockeye salmon on the east side of Nushagak Bay were primarily Wood River stocks. No Distribution of Nushagak Bay Sockeye Salmon fish tagged off Cape Constantine in 1956 were ob- Stocks in Inner Bristol Bay. —Escapement obser- served in Wood or Nushagak River escapements (Fig. vations of sockeye salmon tagged in 1956 and 1959 18). Eighteen fish tagged off Cape Constantine in 1956 (Figs. 17 and 18) indicated the individual stocks com- were captured in set gill nets near the mouth of the prising the run to Nushagak Bay were already Igushik River, which indicates that they were destin- segregated to a certain extent before entering this bay. ed for the Igushik Lake spawning grounds. Few fish This was particularly true for the Wood and Igushik from the 1956 tagging north of the Igushik River River stocks and may also be true for the Snake River mouth (Fig. 18) were recaptured in set nets in the stocks. Igushik River. Most of these tagged fish were observed The recovery distribution of the sockeye salmon in the Wood River (Fig. 18), which indicates that tagged in 1959 at the entrance to Nushagak Bay (Fig. Igushik River fish were not abundant north of the 17) showed Igushik River fish were the most abundant river but probably went directly up the Igushik River stock on the west side of the bay, while Wood River after they entered Nushagak Bay. fish appeared to be the most abundant stock on the My interpretation of the distribution of the east side of the bay. More fish tagged at site 1 on the individual stocks in the sockeye salmon run to west side of Nushagak Bay were observed in the Nushagak Bay is as follows: (1) Igushik River fish are Igushik River escapement than in the Wood River es- already segregated, to a certain extent, from Wood capement and more fish tagged at sites 2, 3, and 4 River stocks before they enter Nushagak Bay; (2) the were observed in the Wood River escapement than in main migration route of Igushik River fish is in the the Igushik River escapement. nearshore area around Cape Constantine, along the The apparent segregation of the individual sockeye west side of Nushagak Bay, and up the Igushik River; salmon stocks comprising the run to Nushagak Bay is and (3) Wood River fish, and probably those of the 22 Consideration of the results of the exploratory tion route of sockeye salmon returning to Bristol Bay fishing and tagging studies in the inshore and offshore is in the offshore waters of the southern half of Bristol areas in their entirety yields a reasonable picture of Bay (Fig. 11). Exploratory fishing and the offshore the distribution and migratory routes of the major and inshore tagging studies showed that Bristol Bay stocks of adult sockeye salmon bound for Bristol Bay. stocks remain in the offshore waters until they are The exploratory fishing in the eastern Bering Sea east within 32 to 80 km of the mouths of their home-river of long. 170°W (Fig. 2) showed that the main migra- systems. 158° 159° Snake and Nushagak Rivers, too, occur farther offshore in the Cape Constantine area. Therefore, these three stocks must enter Nushagak Bay in the middle and on the east side of the bay during migra- tion to their home-river systems. The results of the 1959 tagging in Nushagak Bay suggest that a substantial number of sockeye salmon tagged near the middle of the bay (site 2—Fig. 17) were bound for the Snake River system. The propor- tion of tagged fish observed in the escapements of the Wood and Igushik Rivers was significantly lower for fish from site 2 than sites 1, 3, and 4 (Appendix Table 7). Because the proportion of fishery recaptures of tagged fish was essentially the same for all four sites (Appendix Table 6), removal of tagged fish by the fishery was not regarded as the cause of the lower proportion of tagged fish from site 2 in the escape- ment. Fishery recaptures of fish tagged at site 2 were equally abundant on the east and west sides of Nushagak Bay (Fig. 21), even though the fishing effort on the east side of Nushagak Bay was considerably greater than on the west side. This indicates that more fish tagged at site 2 were on the west side than on the east side and consequently more of the fish should have escaped the fishery to be observed in the spawning escapement. A plausible explanation for their absence in the escapement is that they went to some river system not adequately searched for tagged Figure 22.—General distribution of Bristol Bay stocks of fish. sockeye salmon, showing areas of greatest stock abundance. Reliable observations of tagged sockeye salmon were not made in the Nushagak River escapement, but five tags were recovered in the personal-use gill nets in the main Nushagak River. The personal-use SYNOPSIS OF DISTRIBUTION AND fishery is well above the commercial fishery and below MIGRATORY ROUTES OF SOCKEYE the escapement enumeration towers. The recovered SALMON IN THE EASTERN BERING SEA fish were from taggings at sites 2, 3, and 4 (Appendix AND BRISTOL BAY Table 7) in the middle and on the east side of Nushagak Bay. There were no statistically significant differences in The Snake River system was not checked for tags the distributions of the major stocks of sockeye until late August, when it was discovered it had salmon destined for the fishing districts of Bristol Bay received an unusually large escapement. Most of the between long. 171° and 167°W (Fig. 11). Stocks bound sockeye salmon in the Snake River escapement spawn for Nushagak Bay appeared to be more abundant in on the beaches of Nunavaugaluk Lake (Fig. 1). High the northerly approaches to Bristol Bay, but the winds and rough water during a 3-day survey of this results are inconclusive. The distribution of stocks in lake hampered observations of the spawning fish, but the eastern Bering Sea between long. 167° and 161°W three tags were positively identified. Two of the fish also remains open to question. In the area between had been tagged at site 2 and one at site 3. These Port Moller and Cape Newenham, however, stocks observations are too few to be conclusive, but they do appeared to become segregated into those destined for suggest the distribution noted previously here, i.e. rivers entering on the west and those entering on the Snake River fish are most abundant on the west side east sides of Bristol Bay. Sockeye salmon migrating to and in the middle of Nushagak Bay. Kvichak Bay were abundant in the offshore waters in the southern half of Bristol Bay. Stocks bound for Synopsis: Segregation of Sockeye Salmon Stocks Nushagak Bay were abundant in the offshore waters in the Inshore Region of Bristol Bay. —In Figure 22, farther north. Stocks bound for the Ugashik and I present a generalized picture of the probable migra- Egegik Rivers declined in abundance in the offshore tion routes of various stocks of sockeye salmon as they waters and increased near to shore on the east side of move through Bristol Bay after leaving the Bering Bristol Bay. The tagging in outer Bristol Bay between Sea. Additional tagging is needed in both the near- long. 161° and 158°30'W showed that stock segrega- shore and offshore waters on the north and west sides tion continued toward the head of Bristol Bay (Fig. of Bristol Bay. 22). 24 The results of the tagging in the nearshore areas on these fish were still as much as 200 km from the the west and east sides of inner Bristol Bay also show- mouths of their home-river systems. ed an increase in stock segregation (Fig. 22). 3. Inshore tagging studies showed a continuation of Nushagak Bay sockeye salmon became the most stock segregation toward the head of Bristol Bay. abundant stocks on the west side of inner Bristol Bay, Those sockeye salmon stocks originating in the river and Ugashik and Egegik River fish the most abundant systems of Nushagak Bay became most abundant on stocks on the east side of the inner bay. From this dis- the west side of inner Bristol Bay. They appeared to tribution, I concluded that Naknek, Kvichak, and be somewhat segregated before entering Nushagak Alagnak River fish mostly remained in the offshore Bay. Ugashik and Egegik River sockeye salmon waters until they reached Kvichak Bay in the area became the most abundant stocks on the east side of northeast of Middle Bluff. the inner bay. Naknek, Kvichak, and Alagnak river The various sockeye salmon stocks in the run to sockeye salmon stocks remained offshore until they Nushagak Bay became segregated to a certain extent reached Kvichak Bay in the area northeast of Middle before they entered that bay. The Igushik River stock Bluff. These results are illustrated on a chart of was most abundant in the nearshore area off Cape Bristol Bay. Constantine and along the west side of Nushagak Bay to the Igushik River mouth. The data suggest that Snake River fish were most abundant along the west LITERATURE CITED side and in the middle of Nushagak Bay. The Wood River stock was most abundant on the east side of the BARNABY, J. T. bay, indicating this stock and probably the Nushagak 1952. Offshore fishing in Bristol Bay and Bering Sea. U.S. River stock enter en masse on the east side and in the Fish Wildl. Serv., Spec. Sci. Rep. Fish. 89, 30 p. middle of Nushagak Bay. FRENCH, R. Ugashik sockeye salmon were also declining in 1963. Salmon distribution and abundance on the high seas. abundance in the offshore waters of outer Bristol Bay Int. North Pac. Fish. Comm., Annu. Rep. 1961:92-101. and increasing in abundance nearer to shore on the FRENCH, R., D. CRADDOCK, R, BAKKALA, J. DUNN, and K. east side of inner Bristol Bay. South of lat. 58°N THORSON. Ugashik River fish increased in abundance, becoming 1967. Ocean distribution, abundance, and migrations of most abundant in the nearshore area south of the en- salmon. Int. North Pac. Fish. Coram., Annu. Rep. 1966: trance to Ugashik Bay. 78-89, GILBERT, C. H. Sockeye salmon bound for the Egegik River system 1923. Experiment in tagging adult red salmon, Alaska Penin- were declining in abundance in the offshore waters of sula fisheries reservation, summer of 1922. U.S. Bur. Fish., outer Bristol Bay as far seaward as long. 159°W. They Bull. 39:39-50. apparently the coastal area in greatest reached abun- HARTT, A. C. dance between Middle Bluff and lat. 58°N. 1962. Movement of salmon in the North Pacific Ocean and Naknek and Kvichak River sockeye salmon were Bering Sea as determined by tagging, 1956-1958. Int. North also segregated from each other by the time they Pac. Fish. Comm., Bull. 6, 157 p. entered Kvichak Bay. Fish bound for the Kvichak 1966. Migrations of salmon in the North Pacific Ocean and River were most abundant on the west side and in the Bering Sea as determined by seining and tagging, 1959-1960. middle of Kvichak Bay. Naknek River fish were most Int. North Pac. Fish. Comm., Bull. 19, 141 p. HOKKAIDO UNIVERSITY, THE FACULTY of FISHERIES. abundant in the nearshore waters on the east side of 1968. Data record of oceanographic observations and explora- Kvichak Bay northeast of Middle Bluff. tory fishing. No. 12, 421 p. 1970. Data record of oceanographic observations and explora- SUMMARY tory fishing. No. 14, 429 p. INTERNATIONAL NORTH PACIFIC FISHERIES COMMIS- 1. The results of the exploratory fishing operations SION. in the eastern outer Bristol Bering Sea and Bay show- 1959. Distribution and racial sampling of salmon on the high ed that the main migration route of Bristol Bay seas. Int. North Pac. Fish. Coram., Annu. Rep. 1958:74-78. sockeye salmon is in the offshore waters of the south 1960. Distribution and racial sampling of salmon on the high half of the entrance to the bay and in the south half of seas. Int. North Pac. Fish. Comm., Annu. Rep. 1959:79-85. the bay itself. This migration route is illustrated on a KASAHARA, H. chart of the area. 1963. Salmon of the North Pacific Ocean, Part I. Catch sta- tistics for North Pacific Salmon. Int. North Pac. Fish. 2. Offshore tagging studies showed that there was Coram., Bull. 12, p. 7-82. little segregation of the individual stocks of Bristol KONDO. H., Y. HIRANO, N. NAKAYAMA, and M. MIYAKE. Bay sockeye salmon in the eastern Bering Sea and 1965. Offshore distribution and migration of Pacific salmon outer Bristol Bay as far as a line between Port MoUer (genus Oncorhynchus) based on tagging studies (1958-1961). and Cape Newenham. Toward the head of the bay Int. North Pac. Fish. Coram., Bull. 17, 213 p. line, from this there was a progressive segregation of KOO, T. S. Y. sockeye salmon stocks according to their river system 1962. Age designation in salmon. Univ. Wash., Publ. Fish, of origin. This segregation appeared to begin while New Ser. 1:37-48. 25 LANDER, R. H., G. K. TANONAKA, K. N. THORSON, and T. MATHISEN, 0. A. levels and productivity of the Nushagak A. DARK. 1971. Escapement to 1966. Fish. Bull., U.S. 1966. Ocean mortality and growth. Int. North Pac. Fish. sockeye salmon run from 1908 Comm., Annu. Rep. 1964:105-111. 69:747-763. LANDER, R. H., K. N. THORSON, R. C. SIMON, T. A. DARK, PETERSON, A. E. gillnets on Fraser River sockeye and G. K. TANONAKA. 1954. The selective action of Fish. Comm., Bull. 5, 101 1967. Ocean mortality and growth. Int. North Pac. Fish. salmon. Int. Pac. Salmon p. Comm., Annu. Rep. 1965:99-106. RICH, W. H. experiments in Alaska, 1924 and 1925. MARGOLIS, L.,-F. C. CLEAVER, Y. FUKUDA, and H. GOD- 1926. Salmon-tagging FREY. U.S. Bur. Fish., Bull. 42:109-146. 1966. Salmon of the North Pacific Ocean, Part VI. Sockeye RICKER, W. E. of computations for biological statistics of salmon in offshore waters. Int. North Pac. Fish. Comm., 1958. Handbook fish populations. Fish. Res. Board Can., Bull. 119, 300 p. Bull. 20, 70 p. 26 Appendix Table 1. --Dates of exploratory fishing or tagging and source of data used to show the distribution and migration route of sockeye salmon in the offshore ar«a of Bristol Bay. Date Source of data Exploratory Fishing 27 June-23 July 1939 Barnaby (1952), Table 4, Page 12 6 June-3 July 1940 Barnaby (1952), Table 7, Page 16 17-21 June 1940 Barnaby (1952). Table 9, Page 17 7-11 July 1941 Barnaby (1952), Table 16, Page 20 17-28 June 1958 International North Pacific Fisheries Comnission (1959). Table 2, Page 75 27 June-3 July 1959 International North Pacific Fisheries Coimlsslon (1960), Table 2, Page 82 12-25 June 1961 French (1963), Table 9, Page 100 24 June-6 July 1965 French et al . (1967), Figure 8, Page 79 24 June-6 July 1966 French et al. (1967), Figure 8, Page 79 Tagging 17-29 June 1957 Hartt (1962) 16-27 June 1958 Hartt (1962) 20 June 1960 Hartt (1966) 28-30 June 1960 Kondo et al. (1965) 20-23 June 1961 Kondo et al . (1965) 19-28 June 1964 Lander et al . (1966) 24 June-2 July 1965 Lander et al. (1967) 27 Appendix Table 2. --Number and percent- of tagged sockeye salmon recovered in catch (conmercial fishery) or observed in escapement from fish released at nine sites in Naknek-Kvichak and Egegik districts in 1955. (See Fig. 13 for location of tagging sites.) Appendix Table 3. --Number and percent- of tagged sockeye salmon recovered in catch (comnercial fishery) or observed in escapement from fish released at 20 sites in Nushagak, Naknek-KvichaK Egegik, and Ugashik districts in 1956. (See Figr. 14 and 15 for location of tagging sites.) Appendix Table 4. --Number of tagged sockeye salmon recovered in catch Appendix Table 4. --Continued. (commercial fishery) from fish released at two sites in Naknek-Kvichak fi shing No. fish recovered in Naknek- district in 1957. (See Fig. 16 for location of tagging sites.) Appendix Table 6. --Number of tagged sockeye salmon recovered in catch Appendix Table 6. --Continued. released at four sites in Nushagak fishing (cotimercial fishery) from fish Tagging No. fish recovered in site No. Naknek- Fig. 17 for location of tagging sites.) district in 1959. (See and fish Togiak Nushagak Kvichak Egegik Ugashik date tagged district district district district district Total Tagging No. fish recovered in ' site No. Naknek- Site 3 and fish Togiak Nushagak Kvichak Egegik Ugashik date tagged district district district district district Total 21 June 17 1 Site 1 25 June 226 38 20 June 2 3 27 June 73 23 June 2 2 29 June 118 26 June 4 4 1 July 310 28 June 22 22 3 July 140 30 June 27 27 8 July 15 2 July 122 36 36 10 July 37 6 July 185 75 75 12 July 17 7 July 27 17 17 14 July 11 9 July 33 6 6 11 July 60 24 26 13 July 72 28 30 15 July 11 2 2 Site 4 Total 771 19 June Percent- 21 June 25 June Site 2 27 June 20 June 11 2 2 29 June 26 June 110 11 11 1 July 343 28 June 31 12 12 e July 11 30 June 330 110 113 10 July 413 2 July 223 82 82 12 July 206 7 July 19 6 6 9 July 66 18 18 14 July 3?_ 11 July 15 10 11 Total 1,071 13 July 20 11 11 Percent-.1/ 15 July 8 3 3 Total 833 Percent- ) Appendix Table 7. --Number and percent- of tagged sockeye salmon observed in escapement from fish released at four sites in Nushagak fishing district in 1959. (See Fig- 17 for location of tagging sites. 646. Weight loss of pond-raised channel catfish Uctalurua punctatus) during holding in 662. Seasonal distribution of tunas and billfiahes in the Atlantic. By John P. Wise and processing plant vats By Donald C. Greenland and Robert L. Gill. December 1971, iii + 7 Charles W. Davis. January 1973. iv -t- 24 pp.. 13 figs., 4 tables. For sale by the Superinten- pp., 3 figs., 2 tables. For sale by the Superintendent of Documents, U.S. Government dent of Documents. U.S. Government Printing Office, Washington, D.C. 20402, Printing Oflice. Washington, D.C. 20402. 663. Fish larvae collected from the northeastern Pacific Ocean and Puget Sound during 649. Distribution of forage of skipjack tuna {Euthynnus pelamis) in the eastern tropical April and May 1967. By Kenneth D. Waldron. December 1972, iii -f 16 pp., 2 figs,. 1 table, Pacific By Maurice Blackburn and Michael Laurs. January 1972. iii + 16 pp.. 7 figs., 3 4 appendix tables. For sale by the Superintendent of Documents, U.S. Government Print- tables, For sale bv the Superintendent of Documents. U.S. Government Printing Office. ing Office. Washington. DC. 20402, Washington. DC 20402. 664. Tagging and tag-recovery experimenta with Atlantic menhaden. Brevoortia tyran- 650. EffecU of some antioxidants and EDTA on.the development of rancidity in Spanish nua. By Richard L. Kroger and Robert L. Dryfoos. December 1972, iv -f 11 pp., 4 figs., 12 mackerel i Scorn beromonts maculatus) during frozen storage. By Robert N. Farragut. tables. For sale by the Superintendent of E)ocumenta, U.S. Government Printing Office, Februar>' 1972, iv + 12 pp.. 6 figs., 12 tables. For sale by the Superintendent of Washington. D.C. 20402. Documents, U.S. Government Printing Office. Washington. D.C. 20402. 665. Larva) fishsurveyofHumbolt Bay. California. By Maxwell B. Eldridge and Charles 651. The effect of premortem stress, holding temperatures, and freezing on the F. Bryan. December 1972. iii + 8 pp.. 8 figs., 1 table. For sale by the Superintendent of biochemistry and quality of skipjack tuna. By Ladell Crawford. April 1972. iii + 23 pp.. 3 Documents. U.S. Government Printing Office. Washington. D.C. 20402. figs.. 4 tables. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington. DC. 20402. 666. Distribution and relative abundance of fishes in Newport River. North Carolina. By William R. Turner and George N. Johnson. September 1973. iv -I- 23 pp.. 1 fig.. 13 tables. with 12.5-meter (Headrope) GulT-of- 653. The use of electricity in conjunction a Mexico For sale by the Superintendent of Documents, U.S. Government Printing Office, iv -f 4 shrimp trawl in Lake Michigan. By James E, Ellis. March 1972. 10 pp.. 11 figs.. Washington. D.C. 20402. tables. For sale by the Superintendent of Documents. U.S. Government Printing Office, Washington. DC. 20402. 667. An analysis of the commercial lobster (Homarus americanus) fishery along the coast of Maine. August 1966 through December 1970. By James C. Thomas. June 1973, v + 51 654. An electric detector system for recovering internally tagged menhaden, genus pp.. 18 figs.. 11 tables. For sale by the Superintendent of Documents. U.S. Government Brevoortia. By R. O. Parker. Jr. February 1972, iii + 7 pp.. 3 figs.. 1 appendix table. For Printing Office. Washington, D.C. 20402, sale by the Superintendent of Documents. U.S. Government Printing Office. Washington. D.C. 20402. 668. An annotated bibliography of the cunner, Tautogolabrus adspersus (Walbaum). By 665. Immobilization of fingerling salmon and trout by decompression. By Doyle F. Fredric M. Serchuk and David W. Frame, May 1973, ii + 43 pp. For sale by the Sutherland. March 1972. iii + 7 pp,. 3 figs.. 2 tables, For sale by the Superintendent of Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. Documents. U.S. Government Printing Office. Washington, D.C. 20402. 20402. Allen T. Costello. May 656. The calico scallop. Argopecten gibbus. By Donald M. and J. 669. Subpoint prediction for direct readout meteorological satellites. By L. E. Eber. 1972, iii + 19 pp.. 9 figs.. 1 table. For sale by the Superintendent of Documents, U.S. August 1973, iii + 7 pp., 2 figs., 1 table. For sale by the Superintendent of Documents, Government Printing Office. Washington, D.C. 20402. U.S. Government Printing Office. Washington. D.C. 20402. 667. Making fish protein concentrates by enzymatic hydrolysis. A status report on 670. Unharvested fishes in the U.S. commercial fishery of western Lake Erie in 1969. By research and some processes and products studied by NMFS. By Malcolm B. Hale. Harry D. Van Meter. July 1973. iii + 11 pp.. 6 figs., 6 tables. For sale by the Superinten- November 1972, v + 32 pp.. 15 figs.. 17 tables, 1 appendix table. For sale by the dent of Documents. U.S. Government Printing Office, Washington, D.C. 20402. Superintendent of Documents. U.S. Government Printing Office, Washington. D.C. 20402, 671. Coastal upwelling indices, west coast of North America. 1946-71, By Andrew 668. List of fishes of Alaska and adjacent waters with a guide to some of their literature. Bakun. June 1973, iv + 103 pp.. 6 figs.. 3 tables. 45 appendix figs. For sale by the By Jay C. Quast and Elizabeth L. Hall. July 1972, iv + 47 pp. For sale by the Superinten- Superintendent of Documents, U.S. Government Printing Office. Washington, D.C. dent of Documents. U.S. Government Printing Office, Washington, D.C. 20402. 20402. 659. The Southeast Fisheries Center bionumeric code. Part I: Fishes. By Harvey R. 672. Seasonal occurrence of young Gulf menhaden and other fishes in a northwestern Bullis. Jr.. Richard B. Roe. and Judith C. Gatlin. July 1972, xl + 95 pp.. 2 figs. For sale by Florida estuary. By Marlin E. Tagatz and E. Peter H. Wilkins. August 1973. iii + 14 pp.. 1 the Superintendent of Documents. U.S. Government Printing Office. Washington. D.C. fig.. 4 tables. For sale by the Superintendent of Documents. U.S. Government Printing Of- 20402. fice. Washington. D.C. 20402. 660. A freshwater fish electro-motivator (FFEM)-its characteristics and operation. By 673. Abundance and distribution of inshore benthic fauna off southwestern Long Island. James E. Ellis and Charles C. Hoopes. November 1972, iii + 11 pp., 9 figs. N.Y. By Frank W. Steimle. Jr. and Richard B. Stone. December 1973. iii + 50 pp.. 2 figs.. 5 appendix tables. 661. A review of the literature on the development of skipjack tuna fisheries in the cen- tral and western Pacific Ocean. By Frank J. Hester and Tamio Otsu. January 1973. iii + 674. Lake Erie bottom trawl explorations. 1962-66. Edgar Bowman. January 1974. 13 pp.. 1 fig. For sale by the Superintendent of Documents, U.S. Government Printing Of- By W. fice, Washington. 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