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Birds eat krill, squid, and fish. Adelie penguins are 

 the most abundant species (measured by biomass) south of 

 the Convergence. They consume very large amounts of krill 

 in proportion to their body weight (Prevost and Sapin- 

 Jaloustre, 1965; Prevost, in press) . They are eaten by 

 leopard seals and killer whales (Gilbert and Erickson, 

 1977) . 



5. Seals 



The crabeater seals, whose population may be as high as 

 30 million individuals, are the most abundant seal in the 

 Antarctic region and the most abundant seal in the world. 

 They are residents of the pack ice region and feed mainly on 

 krill. Other pack ice seals are the leopard and Ross seals. 

 Pack ice seals breed in the pack ice region, usually south 

 of 60°S latitude. Distribution of juveniles of these popula- 

 tions is unknown and they may occasionally range north of 

 60°S. Weddell seals inhabit coastal areas of fast ice. Ross 

 and Weddell seals eat fish and squid as well as some krill. 

 Leopard seals are predatory, eating mainly krill but also some 

 fish, the young of other seal populations and occasionally 

 penguins . 



Elephant seals and fur seals breed on islands near the 

 Convergence. The main population of the fur seal Arctocephalus 

 gazella is at South Georgia. Other fur seals breed north of 

 the Convergence. Elephant seals eat fish and squid; fur 

 seals eat mainly krill. Elephant seals and fur seals are 

 also resident in the Antarctic region (Erickson, et a_l, 1971; 

 Erickson and Hofman, 1974; Appendix H, BIOMASS, 1977). 



6. Whales 



Whales are circumpolar in distribution. The baleen 

 whales, or fin, blue, sei, humpback and minke whales, migrate 

 into Antarctic waters during the austral summer to feed on 

 krill. Southern right whales are occasionally found south 

 of the Convergence. Baleen whales are found south of the 

 Convergence from November through March. Individual animals 

 average about four months feeding in the area. Whales feed 

 in open water. The larger species and larger individuals 

 within species penetrate further south, approaching the edge 

 of the pack ice. While feeding intensively in Antarctic 

 waters, baleen whales increase about 50% in weight during the 

 sumirier season (Mackintosh and Brown, 19 74; Laws, 19 77a; 

 Appendix H, BIOMASS, 1977) . 



Sperm whales, killer whales and some small cetaceans are 

 probably resident in the Antarctic region. A third of the 

 exploitable male sperm whale stock is assumed to feed south 



