FISHERY BULLETIN: VOL. 72, NO. 2 



Japanese mothership fleet between long. 180° and 

 ITS^W in the Bering Sea in June occur from the 

 Aleutian Islands to lat. SS^N, and fairly good 

 catches may extend to lat. 58^N (Peterson, 1971). 

 U.S. research vessels have made large catches of 

 maturing sockeye salmon in June near the 

 Pribilof Islands — which indicate migrations far 

 north of the Aleutian Islands. The entry of most 

 sockeye into Bristol Bay, however, is apparently 

 off the southern coast of the bay. Gill-net 

 sampling near Bristol Bay, before the fishing 

 season, between long. 165^ and 160^W indicated 

 that the largest concentration of sockeye salmon 

 was about 40 miles (74 km) from the Alaska 

 Peninsula (French, Craddock, and Dunn, 1967). 

 Paulus (1968)^ reported the largest catches in this 

 area to be from 40 to 60 miles (74 to 111 km) 

 offshore. 



Third Year at Sea 



Most age .2 sockeye that do not mature after 

 their second year at sea remain an additional year 

 in the ocean and then return to Bristol Bay to 

 spawn as age .3 fish. A few fish will stay at 

 sea still another year to return as age .4 fish. 



*Paulus, R. D. 1968. Bristol Bay intermediate high seas 

 inshore test fishing program. Project AFC-6-2, 1968 field 

 season. Alaska Dep. Fish Game, Annu. Tech. Rep. Anadro- 

 mous Fish Proj., 61 p. 



but they make up a very small percentage of the 

 Bristol Bay run. From 1960 to 1965 the estimated 

 number of age .4 fish in the spawning run ranged 

 from 2,300 fish to 25,600 fish or from 0.01% to 

 0.22% of the total run. 



Immatures Age .2 (July-December) 



The immature age .2 sockeye were shown to 

 move south and separate from the concentrations 

 of maturing fish of age .2 in the winter. In the 

 winter and spring, they become intermixed with 

 the newly arrived age .1 immatures. In the 

 summer, they probably repeat the migration they 

 made the previous summer as age .1 fish since 

 age .2 immatures are intermixed with age .1 

 fish in all areas sampled. Machidori (see foot- 

 note 7) shows the immature age .2 sockeye in the 

 Bering Sea in the same general areas as the age 

 .1 sockeye. 



Maturing Age .3 (January-June) 



The maturing age .3 sockeye, in the winter, are 

 generally distributed in northern areas of the 

 North Pacific Ocean, and in January and 

 February they were also found in the Bering Sea 

 (Figure 23). In these areas, the distribution of 

 age .3 fish overlaps considerably with that of 



Figure 22. — Tagging location for maturing sockeye salmon tagged in the North Pacific Ocean 

 in April, May, and June 1956-67 and recaptured in Bristol Bay or the Japanese mothership fishery. 

 Percentage recovery for each 5^ of longitude is shown below. 



608 



