510 



Fishery Bulletin 88(3), 1990 



121°W 



120"W 



iirw 



iis-w 



in-w 



34°N 



33°N 



32"N 



San Miguel Is 



Santa Rosa Is 



I. OS Angeles 



San Nicolas Is. 



SAN CLEMENTE IS. 



an Diego 



Unil.eJ.!!^'-''--- 

 Mexico 



121°W 



120''W 



119"W 



1 1 8"W 



Figure 1 



Map showing Southern California Bight (SCB) and San Cleniente Island (SCI). 



scats, (2) dried scats representing one between-trip in- 

 terval, and (3) dried scats representing more than one 

 between-trip interval. Fresh scat samples represented 

 the diet of sea lions within 3 to 4 days of the collec- 

 tion. The second category provided dietary informa- 

 tion from the previous scat collection period to the time 

 represented by fresh scats. The third category repre- 

 sented a much longer period. 



Each scat was placed in a plastic bag, stored in an 

 air-tight plastic container, and frozen until processed. 

 Scats were soaked in a mild soap solution for 1-5 days, 

 and then rinsed with water through two or three nested 

 sieves. During September 1981-March 1983 we used 

 three sieves (mesh sizes 2.8 mm, 1.5 mm, and 1.00 mm) 

 and during April 1983-September 1986 we used two 

 sieves (mesh sizes 2.8 mm and 0.710 mm). After rins- 

 ing, we collected fish otoliths, cephalopod beaks, shark 



teeth, and cartilaginous vertebrae. Otoliths, shark 

 teeth, and cartilaginous vertebrae were air dried and 

 stored in gelatin capsules; cephalopod beaks were 

 stored in vials containing 70% ethanol. We noted the 

 presence or absence of fragments of pelagic red crabs 

 Pleuroncodes planipes. 



Sample analysis 



Prey items were identified to the lowest taxon possible 

 from comparative specimens and drawings (Iverson 

 and Pinkas 1971, Eschmeyer et al. 1983). We used 

 sagittal otoliths to identify teleost fishes, cephalopod 

 beaks to identify squid and octopus, teeth to identify 

 elasmobranchs, and exoskeletal fragments to identify 

 pelagic red crabs. We counted left and right sagittal 

 otoliths, and upper and lower cephalopod beaks. 



