358 



Fishery Bulletin 103(2) 



Odd year smolts 



Even year smolts 



Circuli pair 



Figure 2 



Average seasonal scale growth for Kvichak and Egegik ocean age-3 sockeye 

 salmon (Oncorhynchus nerka) that entered the ocean as smolts during odd 



( ) and even ( ) numbered years, 1952-2000. Growth of salmon 



spending one (age 1.3) and two years (age 2.3) in freshwater are shown 

 separately. Circuli pair ordering restarts at the beginning of each new 

 growing season (SW1, SW2, SW3, SWPL). 95 f 7r confidence intervals (CIs) 

 are shown at each measurement. 



after the fish entered Bristol Bay during May and early 

 June, reaching peak growth near the fifth circuli (Fig. 2). 

 Thereafter, growth declined steadily to a minimum at 

 the first ocean annulus (circuli 18-22). 



Peak scale growth of age-2. smolts was significantly 

 greater compared with that of age-1. smolts for both 

 Kvichak (df=79, i=5.757, P<0.001) and Egegik salm- 

 on (df=73, £=4.667, P<0.001). During the first eight 

 circuli, age-2. smolts averaged 6.5% greater growth 



than age-1. smolts. Thereafter (circuli 11-20), growth 

 of age-2. smolts declined more rapidly and averaged 

 2.3% (Kvichak) to 6.1% (Egegik) less than growth of 

 age-1. smolts. 



Within the SW1 growth period, no statistically sig- 

 nificant difference in circuli growth was detected be- 

 tween smolts entering the ocean during odd- and even- 

 numbered years (P>0.05). However, there was a trend 

 for greater growth among even-year smolts in some 



