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Proposed PCS Lease Sale #87 

 Diapir Field, Alaska 



The Diapir Field lease sale, tentatively scheduled for 

 June 1984, involves 3,355 blocks (approximately 18 million 

 acres) of submerged lands in the Beaufort and Chukchi Seas 

 off Alaska's north coast. The DEIS prepared by the Minerals 

 Management Service noted that: four species of endangered 

 whales (bowhead, gray, right, and sei whales) may be affected 

 by the proposed action; it is unlikely that right or sei 

 whales would be adversely affected; oil spills and disturbances 

 associated with the proposed action are likely to have minor 

 effects on gray whales; and the combined effects of noise, 

 other disturbances, and oil spills on bowhead whales are not 

 expected to exceed the moderate level. The DEIS also concluded 

 that the combined effects of offshore oil and gas activities 

 in the area are not expected to exceed moderate levels with 

 regard to non-endangered marine mammals. 



The Commission, in consultation with its Committee of 

 Scientific Advisors, forwarded its comments and recommendations 

 to the Service on 10 November 1983. Concerning endangered 

 marine mammals, the Commission noted that most of the conclusions 

 in the DEIS were supported by the information provided, but 

 that additional consideration and analysis were needed with 

 respect to the possible effects of oil spills and disturbance 

 on bowhead whales in their feeding areas, particularly those 

 east of Barter Island in the lease sale area. Since the 

 Biological Opinion being prepared by the National Marine 

 Fisheries Service had not been completed at the time the 

 DEIS was issued, the Commission suggested that potential 

 mitigation measures identified in the DEIS be revised, as 

 necessary, in the FEIS to address any reasonable and prudent 

 alternatives and recommendations identified in the Opinion 

 with respect to protecting endangered whales in the proposed 

 lease sale area. 



With respect to non-endangered marine mammals, the 

 Commission noted that the assessment appeared to underestimate 

 possible effects of oil spills and disturbances on polar 

 bears. Among other things, the Commission recommended that 

 the DEIS be expanded to provide further information and 

 analysis concerning: the effect of acoustic and visual 

 disturbances associated with OCS-related facilities and 

 activities on the use of preferred coastal denning sites by 

 pregnant female polar bears; and the likelihood that disposal 

 of food wastes in garbage dumps near construction sites, 

 camps, and other facilities could lure polar bears into 



