CHAPTER X 



OUTER CONTINENTAL SHELF OIL AND GAS DEVELOPMENT 



Activities and oil spills associated with exploration and 

 development of offshore oil and gas resources may adversely 

 affect marine mammals and the ecosystems of which they are a 

 part. Under the Outer Continental Shelf (OCS) Lands Act, the 

 Department of the Interior's Minerals Management Service is 

 responsible for predicting, detecting, and avoiding or 

 mitigating the adverse effects of OCS exploration and develop- 

 ment. The National Marine Fisheries Service and the Fish and 

 Wildlife Service are responsible, under the Marine Mammal 

 Protection Act and the Endangered Species Act, for reviewing 

 proposed actions and advising the Minerals Management Service 

 of measures that may be needed to assure that those actions 

 will not be to the disadvantage of marine mammals and other 

 wildlife. The Commission reviews relevant policies and 

 activities of these agencies and recommends actions that 

 appear necessary to protect marine mammals and their habitats. 

 The Commission's activities in this regard in 1988 are discussed 

 below. 



Proposed OCS Lease Sale #91 

 Northern California 



Lease Sale #91, tentatively scheduled for February 1989, 

 involves leasing up to 223 blocks (approximately 1.1 million 

 acres) of submerged lands 3 to 27 miles off the coast of 

 northern California. Marine mammal species occuring in the 

 area include at least 21 species of cetaceans (including seven 

 species of endangered whales) , five species of seals and sea 

 lions, and the southern sea otter (listed as threatened under 

 the Endangered Species Act). The Minerals Management Service's 

 Draft Environmental Impact Statement (DEIS) on the proposed 

 action was provided to the Commission and others for review 

 and comment in December 1987. The Commission, in consultation 

 with its Committee of Scientific Advisors, reviewed the DEIS 

 and, by letter of 11 March 1988, provided comments to the 

 Minerals Management Service. 



In its letter, the Commission noted that the DEIS provided 

 a thorough assessment of the ways that marine mammals hypotheti- 

 cally could be affected by seismic surveys, vessel and aircraft 

 traffic, drill rig and pipeline construction and operation, 

 oil spills, etc . that could result from Sale #91. However, 

 the DEIS did not identify possible indirect (food-chain) effects 

 or provide a thorough, objective, and adequate assessment of 



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