lakes; chum salmon [0. keta) and pink salmon in 

 salt-water estuaries and bays. The physiological 

 change from fresh water to salt water is highly 

 significant, but the ecological change is not. The 

 young salmon needs a place with food and pro- 

 tection from its enemies, and this it finds along the 

 shores of lake, river, or estuary. After it reaches 

 a length of about 5 to 8 cm. it may move to bigger 

 waters where the feeding is better, and at a size 

 of 10 to 15 cm. it usually seeks the open sea. This 

 is where our story of the ocean migrations begins. 



OCEAN MIGRATIONS OF PINK SALMON 

 OF SOUTHEASTERN ALASKA AND 

 BRITISH COLUMBIA 



Of the Pacific salmons, pink salmon probably 

 have the least complicated oceanic migrations be- 

 cause of their short and uniform 2-year life his- 

 tory. The pink salmon stocks about which we have 

 the most comprehensive knowledge of migrations 

 are those of southeastern Alaska and British 

 Columbia originating between Cape Flattery, 

 Wash. (lat. 48° N.), and Cape Spencer, Alaska 

 (lat. 58° N.)— figure 1. Washington State pink 

 salmon form part of these stocks in odd-numbered 



Figure 1. — Base map of North Pacific area aud surface 

 circulation (adapted from Dodimead et al., 1963, fig. 

 109). 



years. Spawning takes place from mid-July to 

 mid-October, but tends to be earlier in the more 

 northerly areas. Fry emerge from the gravel from 

 February through June; the peak period is in 

 April and May (Sheridan, 1962 : Neave, 1966) . The 

 fry immediately migrate downstream to salt water 

 and then feed in schools along the shores of 



estuaries and bays for 2 or 3 months. As they attain 

 a size of 5 to 6 cm., they venture farther offshore.^ 

 They migrate to the ocean proper in July, August, 

 and September, at a length of 12 to 15 cm. (Gil- 

 housen, 1962; Neave, 1966; Hartt, Dell, and 

 Mathews, 1966). 



The ocean migratory period of these stocks, typi- 

 cal of that of pink salmon, extends approximately 

 from July of the year after spawning until sum- 

 mer or early autumn of the next year. On the basis 

 of recent research, we can now describe or 

 hypothesize within moderate limits of depend- 

 ability the migrations of the southeastern Alaska 

 and British Columbia pink salmon throughout es- 

 sentially all stages of their 12 to 14 months at sea. 



SUMMER EMBARKATION 



Juvenile pink salmon enter the ocean proper at 

 numerous points along the southeastern Alaska- 

 British Columbia coast during July, August, and 

 September; their abundance apparently peaks in 

 August (Martin, see footnote 3 ; Hartt et al., 1966) . 

 They do not scatter randomly seaward, but turn 

 northward and migrate along the coast in a narrow 

 band extending about 20 miles (37 km.) offshore 

 (Hartt et al., 1966). They continue in this manner 

 around the northern periphery of the Gulf of 

 Alaska and southwestward past Kodiak Island. 

 The band widens, in the northern part of the Gulf, 

 presumably because there the Continental Shelf is 

 wider. Stocks other than those from southeastern 

 Alaska and British Columbia undoubtedly join 

 the procession oi!' Prince William Sound, Cook 

 Inlet, and Kodiak Island (Hartt, Smith, and Dell, 

 1967). 



The width of the band and the northerly direc- 

 tion of migration were determined by fishing a 

 large, fine-meshed purse seine at various distances 

 from shore and by facing the net in o^jposed direc- 

 tions. The seine was set in a semicircle, held open 

 for 30 minutes, and then closed to collect fish 

 migrating toward the opening of the seine. Catches 

 were large when the seine was held open to the 

 southeast and small when open noi-thwest (Hartt 

 et al., 1966). For example, in 1964 off southeastern 

 Alaska, the average catch was 350 fingerlings when 



3 Martin, John W. 1064. Studies of estuarine and insliore marine 

 oecilosry of juvenili' pink salmon in soutlieastern Alaska. In W. J. 

 McNeil (editor), Report of the 1964 northeast Pacific pink salmon 

 workshop and contributed papers. U.S. Fish Wildl. Serv., Bur. 

 Comm. Fish., Biol. Lab., Auke Bay, Alaska, Manuscript Rep. 

 64-5 : 80-83. 



MODELS OF OCEANIC MIGRATIONS OF PACIFIC SALMON 



44c 



