FISHERY BULLETIN: VOL. 72, NO. 2 



Table 1.— Proportion of age 2.1 sockeye salmon in samples 

 from the northeastern Pacific and south of Adak Island in 1962, 

 1967, and 1969 and of age 2.2 sockeye in the following year's 

 Bristol Bay run. 



was estimated to be about 24% age 2.2 fish (Fredin 

 and Worlund).*' On the basis of age composition, 

 therefore, we can surmise that most of the small 

 fish taken near lat. 46°30'N in the central Aleu- 

 tian area were of Bristol Bay origin and that this 

 is one area occupied by Bristol Bay fish in winter. 

 In the northeastern Pacific Ocean, good catches 

 of age .1 sockeye salmon were made in the winters 

 of 1962, 1967, and 1969. The proportions of age 

 2.1 fish in these catches are shown in Table 1. 

 Also shown are the proportions of age 2.1 fish 

 in the catches made the following summer south 

 of Adak Island (where Bristol Bay fish tradi- 

 tionally predominate as shown by tag returns) 

 and the proportions of age 2.2 fish in the following 

 year's run to Bristol Bay. 



Catches in 1969 probably best illustrate the 

 presence of Bristol Bay fish in the area during the 

 winter season. Progeny of the record-size spawn- 

 ing run to Bristol Bay in 1965 were expected 

 to be abundant and predominate among samples 

 of immature fish at sea in 1969 and as age 2.2 

 maturing fish in returns to Bristol Bay in 1970. 

 The 1969 winter sampling along ISS^'W resulted 

 in relatively large catches of age . 1 sockeye salmon 

 in January which were composed of approximately 

 60% age 2.1 fish (73% in areas of largest catches 

 near lat. 49' and 50'N) as would be expected 

 if they originated from Bristol Bay. The few age .1 

 sockeye taken in more northern waters along this 

 longitude (near lat. 52' to 55°N) were mainly age 

 1.1 fish (82% ); they possibly originated from North 

 American coastal areas eastward of Bristol Bay. 

 The 1969 samples of age .1 sockeye salmon taken 



sPredin, R. A., and D. Worlund. Catches of sockeye salmon 

 of Bristol Bay origin by the Japanese mothership salmon 

 fishery, 1956-70. Natl. Oceanic Atmos. Admin., Natl. Mar. 

 Fish. Serv., Northwest Fish. Cent., Seattle, Wash. (Unpubl. 



manuscr.) 



along long. 165°W had an even higher proportion 

 of age 2.1 fish (83%) than samples taken along 

 long. 155''W and compared more closely to the age 

 composition of samples south of Adak Island in 

 the summer (79% age 2.1) and to the age compo- 

 sition of maturing fish returning to Bristol Bay 

 rivers in 1970 (90% age 2.2). 



The 1967 winter sampling produced catches of 

 age .1 sockeye salmon along long. 162'W which 

 were also similar in age composition (34% age 

 2.1 fish) to that of maturing fish returning to 

 Bristol Bay in 1968 (37% age 2.2). Sampling along 

 long. 155'W in 1967 showed a somewhat dif- 

 ferent proportion of age 2.1 fish (53%) from that 

 along long. 162'W. In 1962 the proportion of 

 age 2.1 fish along long. 155'W also differed 

 substantially from that of maturing fish in Bristol 

 Bay in 1963 (35% age 2.1 along long. 155° W in 

 winter 1962 and 50% 2.2 fish in Bristol Bay 

 in 1963). 



From the above relations, we surmise that 

 sockeye salmon originating from Bristol Bay 

 reach the northeastern Pacific Ocean by January 

 and February of their first year at sea. It appears 

 from age comparisons that they probably pre- 

 dominate eastward to about long. 160'W and 

 possibly to long. 155'W in years of high abun- 

 dance such as in 1969. Their range may extend 

 even farther to the east. Catch data thus demon- 

 strate that Bristol Bay sockeye become widely 

 distributed across the North Pacific Ocean in their 

 first winter at sea and probably extend from near 

 long. 175'E to at least 155"W. 



Catch data also indicated possible routes used 

 by the young fish to move from the Bering Sea 

 into the North Pacific Ocean. Sampling near 

 long. 170°E in the winter of 1965 resulted in a 

 catch of a single age .1 sockeye salmon whereas, 

 as previously shown, large catches were made 

 between long. 175'E and 180". The lack of age 

 .1 fish along long. 170'E and the evidence from 

 age composition that fish from 175'E to 180° were 

 of Bristol Bay origin suggest that the waters 

 near long. 170'E may represent an area separat- 

 ing Asian and Bristol Bay sockeye in winter. Most 

 Asian sockeye salmon are assumed to be located 

 west of long. 170°E. Inasmuch as catches of age .1 

 fish were made in the central North Pacific 

 Ocean from the Aleutian Islands to near lat. 45'N, 

 it is likely that one route of the young fish 

 from the Bering Sea is through central Aleutian 

 Islands passes. In sampling on long. 165°, 160°, 

 and 155° W, we caught few age .1 sockeye north 



594 



