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The squid group, like the fish group, are krill predators 

 and themselves serve as food for other predatory species as 

 well as potentially harvestable resources. The presence of 

 potentially harvestable populations are several trophic levels 

 i.e., herbivores and primary and secondary carnivores, is a 

 characteristic of the Antarctic ecosystem. 



3. Fish 



I 

 Fish stocks are thought to be low in the Antarctic 

 (Gulland, 1970) . In contrast to other oceans, there are not 

 dense shoals of obligate pelagic fish in Antarctic waters. 

 Pelagic fish present in the waters are Myctophidae, the Noto- 

 theniid genera Pleuragramma and Dissostichus , and the Gadoid 

 genus Micromesistius . Although the Myctophidae may be abun- 

 dant in the open ocean, they apparently do not form dense 

 enough concentrations to support a fishery (Appendix H, 

 Everson, 1977) . 



The Antarctic cod or Nototheniids are distributed in 

 coastal areas around islands such as the Scotia Arc, Ker- 

 guelens, Crozet, Bouvet, and in the Magellanic and New Zealand 

 regions. The latter may migrate south to the Ross and 

 Scotia Seas in the summer, but most of the fish populations 

 are probably resident in Antarctic waters. The southern 

 blue whiting Micromesistius australis from the Magellanic and 

 New Zealand regions does migrate into the Antarctic zone only 

 during the summer to feed. The Antarctic tooth fish and 

 Antarctic silverfish are found around the continent over 

 continental shelves. Antarctic cod and some ice fish are 

 being harvested commercially. Other fish species may consti- 

 tute potentially harvestable resources. 



4. Birds 



The Antarctic Convergence is not a barrier for birds 

 because of their mobility. However, breeding of penguins, 

 albatrosses and petrels, cormorants, skuas, ducks, gulls and 

 terns occurs along the coast of the Antarctic continent or 

 on islands between 50°S and 65°S latitude. South Georgia 

 and Kerguelen have the greatest diversity of breeding birds 

 (Watson, et al, 1971; Everson, 1977) . 



Migratory birds are present in the Antarctic ecosystem, 

 either south of the Convergence or on subantarctic islands, 

 for only part of the year for feeding and breeding. The eco- 

 system provides habitat for such bird populations. When they 

 move northward, they export some material from the Antarctic 

 ecosystem. 



