FISHERY BULLETIN: VOL. 71, NO. 3 



sity of Alaska, pers. comm.; Feder and Paul, 

 1973). 



A comparison of growth rates in the three 

 study areas indicates that differences in length 

 at age are less than 2 mm by the end of the 

 sixth year (Figure 6). In older clams the dif- 

 ference in growth rates between individuals 

 from the three study sites is more pronounced. 

 The annual increase in size for individuals 

 6 to 12 yr of age was generally greatest on 

 Shell Beach, and by age 12 specimens from 

 this beach were, on the average, 12 mm longer 

 than those from Eater Beach and 9.5 mm longer 

 than specimens from the Indian Creek Mudflat. 



and 8 where the number of clams surviving 

 as a function of year of settlement are plotted. 

 On the beaches examined, individuals of the 

 1966, 1967, and 1968 year classes are more 

 abundant than those of the 1970 or 1971 year 

 classes, even after surviving 3 to 5 yr of 

 natural mortality. It is also evident that the 

 1964 year class, which represented the newest 

 recruits to the sport fishery in 1971, was not 

 very abundant. 



The total number of young littleneck clams 

 found on the Eater Beach transect (352 clams 

 on a 12-station transect) as compared with the 

 number found on the Indian Creek transect 

 (528 clams on a 10-station transect) indicates 



5 6 7 8 

 Age group 



10 II i2 



Figure 6. — Cumulative growth in shell length for clams 

 from Shell KN = 368) and Eater Beaches (N = 554) 

 and Indian Creek Flat (N = 642). Plotted points 

 represent mean values. 



Recruitment and Distribution 



The number of recruits surviving in a little- 

 neck clam population varies considerably from 

 year to year. This is indicated in Figures 7 



1966 196? 1968 1969 



Year of RecruitmenI 



Figure 7. — Abundance of clams to 7 yr of age on a 

 12-station transect from Eater Beach, Galena Bay. 



1966 1967 1968 1969 



Year of Recruitment 



Figure 8. — Abundance of clams to 7 yr of age on a 

 10-station transect from Indian Creek Flat, Galena Bay. 



672 



