90 



Fishery Bulletin 91(1). 1993 



dives and second in abundance on 9 dives. Of the rock- 

 fish, 76% were large, 21% small, and 3% other. Other 

 commonly observed fish were shortspine thornyhead, 

 flatfish, and walleye pollock (Table 1). 



Distribution of large rockfish 



Large rockfish were solitary or in groups of 2-200 fish. 

 Of the 4020 large rockfish observed, 998 (25%) were 

 solitary and 3022 (75%) were divided about equally 



among groups of 2-10, 11-50, and 51-200 (Table 2). 

 Although 53% of the rockfish were in groups of more 

 than 10 fish, the number of these groups were few: 56 

 groups of 11-50 fish and 9 groups of 51-200 fish, com- 

 pared with 303 groups of 2-10 fish (Table 2). The in- 

 frequent occurrence of large groups probably contrib- 

 utes to the high variability of trawl catch rates 

 encountered during rockfish surveys. 



Regardless of group size, large rockfish were sepa- 

 rated by 1-4 m, were similar in size within each group, 



