FRENCH and BAKKALA: NEW MODEL OF OCEAN MIGRATIONS 



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Total Number 

 of Returns 



Proportion of Returns from: 



[48(553 — W****""" Alaska 



Other N American 



areas 



Asia 



T 



Figure 2. — Tagging locations (2° x 5° areas) for maturing sockeye salmon recovered in western Alaska, other North American 

 areas, and Asia, 1956-69. The proportion of returns to these major land areas from each 2° x 5° area of the ocean are shown 

 diagrammatically by having each 2° x 5° rectangle represent 100%. Small percentage returns could not be accurately 

 illustrated, and in some instances percentages are exaggerated to show presence. 



across most of the North Pacific Ocean and in the 

 central and eastern Bering Sea south of lat. 

 60°N (Figure 2). 



These tagging data also illustrate areas where 

 Bristol Bay sockeye predominate as well as areas 

 where they overlap with other stocks. Although 

 tagging effort varied between some years and 

 was far from uniform in various parts of the 

 ocean, the return showed Bristol Bay sockeye 

 predominating in the spring from about long. 

 155°W to 170°E. Their main area of overlap with 

 other North American stocks was from about long. 

 140° to 160°W. With Asian sockeye, their main 

 area of overlap was between long. 165° and 175°E. 



Tag returns from immature sockeye salmon 

 tagged primarily in the summer (late June 

 through August) have been too few to portray 

 their oceanic distribution in detail (Figure 3). 

 The small numbers of tag returns are due to the 

 poor survival associated with tagging small im- 

 mature fish and the lack of widespread tagging 

 throughout the oceanic areas inhabited by the 

 fish. For limited data, the results show overlap 

 of Bristol Bay sockeye with other North American 



stocks between about long. 145°W and 175°E. 

 Bristol Bay immatures predominate south of the 

 Aleutian Islands. Total returns of tagged fish for 

 all years indicate that in the area immediately 

 south of Adak Island, approximately 10% of the 

 tag returns were from other North American 

 areas. Very few tag returns were reported from 

 Asian streams. The returns suggest some overlap 

 of immature fish of Asian origin with Bristol 

 Bay fish south of the central and western Aleu- 

 tian Islands, but they do not indicate areas where 

 Asian sockeye predominate. 



Recent studies by the National Marine Fisheries 

 Service (NMFS) have been directed toward under- 

 standing the influence of the oceanic environ- 

 ment on distribution and migration of salmon at 

 sea. These studies, primarily concerned with 

 Bristol Bay sockeye salmon, should disclose the 

 causes of change in distribution and movements 

 of the Bristol Bay stock. They should also lead 

 to improved forecasts of run sizes and predictions 

 of the effect of the Japanese high-seas fishery on 

 salmon stocks of the United States. Results of 

 these investigations and conclusions drawn from 



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