C-5 



of sperm whales, seals, oenguins , and some fish. It is 

 possible that they are less abundant in Antarctic than in 

 subantarcti,c areas (BIOMASS, 1977). 



Fish species thought to be of greatest importance in 

 the southern ocean are listed in Table 1. At present, fish 

 are not thought to contribute significantly to the Antarc- 

 tic marine ecosystem (BIOMASS, 1977). Some Antarctic fish 

 species are residents which remain south of the Convergence. 

 Some such as Nototheni a magellanica and Dissostichus 

 eleginoides occur in both subantarctic and Antarctic regions 

 Information to determine whether these species migrate 

 across the Convergence or form separate stocks in the two 

 regions is not yet available (H. DeWitt , conversation of 

 15 November 1977). However, it is unlikely that these are 

 of commercial interest. 



The blue whiting Micromesi stius australis does 

 migrate across the Convergence and is harvested. 



Seals 



Crabeater seals are by far the most abundant species 

 in Antarctic waters (Erickson, et al . , 1971; Laws, 1977). 

 Other seals present in the system are fur, leopard, Weddell, 

 Ross and elephant seals (see Table 2). The crabeater, 

 Weddell, leopard and Ross seals inhabit the pack-ice zone. 

 The fur seal Arctocephalus gazella breeds on islands south 

 of the Antarctic Convergence, primarily South Georgia 

 (BIOMASS, 1977). The crabeater seal consumes mainly krill. 

 Other seals eat fish, cephalopods , and occasionally birds 

 and young seals. 



Whales 



Antarctic whales feed intensively in Antarctic waters 

 in the summer months, increasing about 5 0% in weight. 

 After migrating northward in the autumn, they feed rela- 

 tively little during the winter. Large baleen whales 

 feeding south of the Convergence are fin, blue, sei , hump- 

 back and minke whales. Sperm whales, killer whales, and 

 some smaller toothed whales also feed in Antarctic waters 

 (BIOMASS, 1977). 



Distribution, abundance, and commercial use of Ant- 

 arctic whales are listed in Table 3. Minke whales are 

 assumed to feed for about six months in Antarctic waters, 

 while other baleen whales are present for only about four 

 months. About half of total sei whales and one-third of 

 exploitable male sperm whales feed south of the Convergence 



