though gonatid squids have occurred throughout the fur seals' 

 range, squids of this family were not among the four principal 

 forage species in the areas south of Alaska. 



Oceanic squids of the family Onychoteuthidae, Onycho- 

 teuthis sp. and Onychoteuthis borealijaponicus, are principal 

 prey species of fur seals off California, Washington, and Brit- 

 ish Columbia (Figs. 7, 9, 10). 



The oceanic squid fauna of the North Pacific Ocean and the 

 Bering Sea are poorly known but the population of some 

 pelagic squids can probably be considered large based on in- 

 formation obtained from the analysis of stomach contents of 

 marine mammals and seabirds. Sanger (cited in Mercer 1981 ") 

 presented information on the trophic relationship of seabirds 

 and squids based on stomach contents of seabirds collected in 

 the Gulf of Alaska and the Bering Sea from 1975 through 1978. 

 Sanger estimated that consumption of squids by seabirds dur- 

 ing the summer in Alaska was at least 53,000 1. The population 

 of the two species of gonatid squids, B. magister and G. bore- 

 alis, can be considered a major resource based on fur seal feed- 

 ing data collected during 1958-74 in the eastern Bering Sea. 

 Even in the first feeding studies of fur seals in the Bering Sea, 

 it was revealed that squids were principal forage species (Lucas 

 1899). Currently B. magister is fished commercially by Japan 

 along the shelf edge in the Bering Sea. 20 Fiscus (1982) sum- 

 marized the known predation by 25 marine mammals on squids 

 and the possible predation by 20 other marine mammals in the 

 eastern North Pacific Ocean and Bering Sea. He also discussed 

 the species of squids that may be sufficiently abundant enough 

 to support a commercial fishery. 



Sperm whales are known to feed primarily on squids and 

 should give a good indication of the available benthic squid 

 fauna of the area. Kawakami (1980), in reviewing sperm whale 

 feeding, reported that the frequency of squids in sperm whale 

 stomachs was between 71 and 94% of total stomach contents 

 in sperm whales taken in the Bering Sea-Aleutian area and 

 32% for the Gulf of Alaska. The occurrence of squid and fish 

 in stomachs of sperm whales taken in the Gulf of Alaska and 



"Mercer, R. W. (editor). 1981. Proceedings of the squid workshop. NWAFC 

 Processed rep. 81-11, 34 p. Northwest and Alaska Fish. Cent., Natl. Mar. Fish. 

 Serv., NOAA, 2725 Montlake Blvd. E., Seattle, WA 981 12. 



"R. G. Bakkala, Northwest and Alaska Fish. Cent., NMFS, NOAA, 2725 

 Montlake Blvd. E., Seattle, WA98112, pers. commun. October 1981. 



the Bering Sea- Aleutian area shown in Figure 35 gives some in- 

 dication of the distribution of squids. 



Based on estimated catch per unit of effort (CPUE) data by 

 Japan and the United States (in subareas 2, 3S, and 3N (Fig. 27) 

 in the 100 to 400 fathom (183-732 m) depth zone commonly 

 fished by Japanese and U.S. vessels), the estimated squid bio- 

 mass ranged from 16,842 to 27,037 t. The commercial catch of 

 squids was about 9,000 t in 1978 and has dropped to about 

 5,000 t in recent years (Bakkala footnote 20). The gonatid 

 squid B. magister is fished near the shelf edge while O. boreali- 

 japonicus is fished near the Aleutian Islands. 



Pacific herring. — Pacific herring is important in the food 

 web throughout its range as it is one of the primary forage 

 foods of many animals in the marine environment including 

 fishes, marine mammals, and seabirds. Pacific herring has 

 been among the principal forage foods of fur seals in the east- 

 ern Bering Sea, southeastern Alaska (Sitka Sound), and espe- 

 cially important to fur seals off Washington and British Co- 

 lumbia, Canada (Tables 6, 7). 



The importance of Pacific herring as forage food of fur seals 

 off the Washington-British Columbia coast (Fig. 36) can be at- 

 tributed to an abundant adult herring population estimated at 

 about 350,000 tons and the fact that the main feeding grounds 

 for juvenile and immature herring was located off the Strait of 

 Juan de Fuca and in Hecate Strait (Hourston and Haegele 

 1980). About 200,000 tons of adults (19 billion fish) are found 

 in several major concentrations of individual schools (each 

 containing up to 10,000 tons) scattered along the edges of 

 banks extending along 100 mi of coast off the Strait of Juan de 

 Fuca. These aggregations move north or south during the sum- 

 mer presumably following their food supply with adult herring 

 returning to their offshore feeding grounds in April and May. 

 The abundance of herring in this area is probably the principal 

 reason that Pacific salmon are also leading forage prey of fur 

 seals off Washington and British Columbia (Figs. 9, 10). Both 

 herring and salmon apparently feed on the rich zooplankton in 

 the area. The Hecate Strait population (100,000 tons) is 

 thought to be similar (Hourston and Haegele 1980). 



In the Bering Sea, Pacific herring was one of the principal 

 foods consumed by fur seals taken during August (Fig. 8), 

 north and east of St. Paul Island. This fish represented 31% of 







r 



+ 



a 



/ ., 



+ 



Pribilof Is. 





4. 







"*■■*■ 





Bering Sea 



"*35P'o-'-- 



=. 







*«*> ♦ 





:^ 







\ 



i i i 



Figure 34. — Locations where 473 northern fur seals were collected whose stomachs contained Gonatopsis borealis, 



1958-74. 



27 



