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VI. ENVIRONMENTAL IMPACTS OF PROPOSED ACTION AND ALTERNATIVES 



The proposed federal action represents one point on 

 a continuum of management regimes for Antarctic living 

 marine resources, from totally unregulated harvesting to 

 a ban on all commercial harvesting. Similarly the impacts 

 of each of the alternatives under consideration also fall 

 on a continuum from greatest to least impact on the marine 

 environment. Future activities associated with the devel- 

 opment of non-living resources in Antarctic waters could 

 affect living resources through modifications of the en- 

 vironment. For conservation of living resources, the 

 activity of greatest concern in terms of environmental 

 impact on the Antarctic marine ecosystem is commercial 

 harvesting of renewable resources. Krill is the resource 

 of most immediate interest, but there are other potentially 

 harvestable resources as well: fish, squid, birds, and 

 seals. Under different management regimes there would be 

 different degrees of environmental impact. 



There are three classes of impacts of commercial har- 

 vesting on the Antarctic marine ecosystem. The first and 

 most significant are the impacts of harvesting on the popu- 

 lations of the renewable resources. The impacts are both 

 direct, i.e. changes in abundance of any stock which is 

 harvested, and indirect, i.e. changes in abundance of 

 species which depend on the harvested stock for food. The 

 second are the impacts of shipping traffic and harvesting 

 operations on the local marine environment. The third is 

 the impact of increased human activity on a relatively un- 

 disturbed marine ecosystem. The range of possible impacts 

 of harvesting on stocks, on the marine environment, and on 

 the southern ocean as a relatively undisturbed habitat 

 will be discussed. Then the degrees of impact anticipated 

 from the proposed federal action and the alternatives will 

 be compared. 



A. Impacts of Commercial Harvesting 



1. Impacts Unaffected by Proposed Action 



There are some environmental impacts of human activity 

 in the Antarctic Ocean which will not be affected by the 

 conclusion of the proposed conservation regime, specifical- 

 ly sealing and whaling. Sei whales, minke whales and sperm 

 whales are harvested in the Antarctic while fin, blue, hump- 

 back and southern right whales are protected under the 

 International Whaling Convention, Harvesting of crabeater. 



