332 



Fishery Bulletin 89(2), 1991 



Figure 1 



Map of Southern California Bight showing location of San Nicolas Island. 



1984 through spring 1985. Jack mackerel was found 

 in scats more often in summer 1981 through autumn 

 1983 than after that period. Rockfish were commonly 

 found in winter 1982, and spring 1984 through spring 

 1985. Market squid was more common in the diet prior 

 to 1983 and its frequency of occurrence was higher in 

 either autumn or winter, or both, each year except in 

 1984. Pelagic red crabs Pleuroncodes planipes ap- 



peared in scats in 1983, were frequently eaten through 

 1985, and then disappeared from the sea lions' diet. 

 Pacific mackerel occurred frequently in summer and 

 autumn 1982. Octopus spp. were eaten more often in 

 spring 1984 than at any other time and appeared in 

 the diet mostly in spring and summer of all years. 



About 69% of all scats contained one or two prey taxa 

 (Fig. 3). There were significant season-year interac- 

 tions (jP<0.05) for all years and seasons, but the num- 

 ber of prey taxa occurring in each scat was greatest 

 from 1981 through 1984 and least in 1985 and 1986 

 (Fig. 3). 



Discussion 



California sea lions forage in a number of different 

 habitats and depth strata in the Gulf of California and 

 along the North American Pacific coast from Baja 

 California to British Columbia. The composition of the 

 sea lions' diet varies geographically (Jameson and 



