60"N, 



se-N. 



54°N. 



52°N, 



50°N, 



48»N 



@ 14 RECOVERIES 



RELEASED 6/23-7/1 



3J 20 RECOVERIES 



RELEASED 6/8-6/29' 



I60°E. 



165* E. 



I70°E. 



I75*E. 



180* 



I75'W. 



I70*W. 



Figure S. — High-seas and coastal recoveries of pink salmon tagged at three points in the North Pacific Ocean and 



Bering Sea in 1959. 



over 80 liercent of the run arrives within 9 to 22 

 days, and this arrival period occurs regiUarly be- 

 tween June 23 and July 18 (Royc?, 1965)."^ The 

 peaks of the run vary only from July 2 to July 9. 

 The ocean migrations of the Bristol Bay sockeye 

 salmon liave been studied intensively more than 

 10 years (International Xorth Pacific Fisheries 

 Commission, 1957-66). Excellent data are avail- 

 able for the spring- and summer periods, and some 

 winter data are available, so that the entire migra- 

 tory pattern can be inferred. 



FIRST YEAR AT SEA 



The smolts from the five main river systems 

 ent«r the coastal waters of Bristol Bay in an inten- 

 sive mass migration that peaks sliarply during 



Jiuie. Their length at this stage typically ranges 

 from 7 to 12 cm., varying according to river system 

 and fresh-water age. During July, they travel at 

 least as far westward as long. 164° W. (250 miles 

 [463 km.] from the Naknek-Kvicliak estuary) and 

 are apparently most abundant uear the Alaskan 

 Peninsula. Observations at this stage are based on 

 limited purse seining in 1962 and 1966 (unpub- 

 lished) . Purse seine catches ranged up to 1,300 fish 

 per set. At this stage they feed heavily on euphau- 

 sids and larval fish and grow rapidly : the average 

 size of those in the westernmost samples ranged 

 from 13 to 15 cm. in July. 



After this early marine stage, data on their 

 migrations are few until tliey appear a year later 



MODELS OF OC'EAXIC MIGRATIONS OF PACIFIC SALMON 



449 



