360 



Fishery Bulletin 103(2) 



Odd year smolts 



Even year smolts 



Circuli pair 



Figure 4 



Percent change in scale growth of ocean age-3 sockeye salmon (O. nerka) 

 entering the ocean during 1977-97 from those entering the ocean during 

 1952-76. Growth patterns represent smolts entering the ocean during 

 odd- ( ) and even-numbered years ( ). Even-year smolts encoun- 

 ter odd-year pink salmon (O. gorbuseha) during their second year at sea 

 (SW2), but they encountered even-year pink salmon during the their third 

 year at sea (SW3). 



15% increase in growth after 1976. In contrast, growth 

 near the winter annulus (circuli 20-22) was up to 5% 

 lower after the 1977 climate shift. 



Second year (SW2) growth of ocean 

 age-3 sockeye salmon 



At the beginning of the second growing season (SW2), 

 when Bristol Bay sockeye salmon are farthest south 



in the North Pacific Ocean (French et al., 1976), scale 

 growth of both stocks and age groups increased rapidly, 

 but the rate of increase was 59% less than that of SW1 

 and 377, less than SW3 growth (Fig. 2). Peak growth 

 occurred near circuli 5 or 6 and it averaged 15% lower 

 than that of SW1 growth. 



During their second year at sea, even-year sockeye 

 smolts inhabited the North Pacific and Bering Sea when 

 Asian pink salmon were abundant in offshore waters 



