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leopard, Ross and Weddell seals is regulated under the 

 Convention for the Conservation of Antarctic Seals, which 

 has recently entered into force. The Convention for 

 Antarctic Seals applies only south of 60°S latitude. All 

 breeding by pack ice and fast ice seals does occur south 

 of eCS although distributions of juveniles may occasional- 

 ly extend north of that latitude during part of the year. 

 Only those nations which are parties to the International 

 Whaling Convention and the Convention for Conservation of 

 Antarctic Seals are bound by the policies developed under 

 those conventions. The possibility of unregulated har- 

 vesting by other nations does exist. 



2. Direct Impacts on Exploited Stocks 



The greatest environmental concerns over commercial 

 harvesting in the Antarctic are the direct impacts of a 

 harvest on the resource stocks themselves. 



The Scotia Sea, Weddell Sea region is the only known 

 area of krill ( E. superba ) spawning. At the same time it 

 is one of the areas of greatest abundance of krill and is 

 likely to be a region subject to intensive harvesting. 

 Overexploitation of gravid individuals before reproduction 

 occurs would jeopardize maintenance of a breeding stock. 

 The same problem may occur in other geographic regions of 

 krill abundance, but that cannot be determined until it is 

 known whether krill are one or several breeding stocks. 

 Geographic considerations will be important in management 

 of krill harvesting. 



Even though krill are very abundant, the possibility 

 of their overexploitation is a real one. Krill abundance 

 is estimated at 200 to 600 million tons in the summer. 

 Since krill have a very long life span for zooplankton, 

 their productivity may also be relatively low. The rate 

 at which the krill population is replaced is not known at 

 present. Therefore it i s impossible to estimate sustain- 

 able yield with any accuracy. Nonetheless, expectations 

 for krill harvesting are high. Present total world har- 

 vest of marine resources is around 70 million metric tons 

 per year. Estimates for potential annual krill harvest 

 range up to 150 million tons in the scientific literature 

 (Everson, 1°"1) and up to 200 million tons in the popular 

 press (Gwynne, 1977). After consideration of possible re- 

 placement rates, of increases in other krill predators 

 with che decline of 'i.ales, and of the desirability of re- 

 covery of baleen whaie populations, a sustainable annual 

 harvest appears to be less than one-third of these esti- 

 mates (Green, 1977) . A potential for an enthusiastic 



