Chapter Vm 



OUTER CONTINENTAL SHELF OIL, GAS, AND 

 MINERAL DEVELOPMENT 



Exploration and development of coastal and off- 

 shore oil, gas, and hard mineral resources may 

 adversely affect marine mammals and the ecosystems 

 of which they are a part. Under the Outer Continen- 

 tal Shelf Lands Act, the Department of the Interior's 

 Minerals Management Service is responsible for 

 assessing, detecting, and mitigating the adverse effects 

 associated with such activities in offshore water 

 beyond state jurisdiction. Under the Marine Mammal 

 Protection Act and the Endangered Species Act, the 

 National Marine Fisheries Service and the Fish and 

 Wildlife Service are responsible for reviewing pro- 

 posed actions and advising the Minerals Management 

 Service and other agencies of measures needed to 

 ensure that those actions will not have adverse effects 

 on marine mammals or endangered or threatened 

 species. The Commission reviews relevant policies 

 and activities of these agencies and recommends 

 actions that appear necessary to protect marine mam- 

 mals and their habitats. The Commission's activities 

 in this regard in 1991 are discussed below. 



Proposed OfTshore Lease Sales 



The Marine Mammal Conunission, in consultation 

 with its Committee of Scientific Advisors, reviews 

 and comments on proposed outer continental shelf oil, 

 gas, and hard mineral lease sales. During 1991, the 

 Commission commented to the Minerals Management 

 Service on proposed lease sales in the Gulf of Mexico 

 and a request for information on a possible lease sale 

 in Cook Inlet, Alaska. 



Oil and Gas Lease Sales #139 and 141, 

 Central and Western Gulf of Mexico 



In 1990, the Minerals Management Service issued 

 a call for information and notice of intent to prepare 

 an environmental impact statement for two proposed 

 Gulf of Mexico lease sales to be held in 1992. As 

 noted in the previous Annual Report, the Commission, 

 in consultation with its Committee of Scientific 

 Advisors, responded to the Service's request by letter 

 of 20 June 1990. 



The Service decided to proceed with the two sales 

 and on 11 April 1991 announced plans for oil and gas 

 lease sales #139 and #141. The proposed sale areas 

 includes approximately 29. 1 and 23.5 million acres of 

 submerged lands in the central and western Gulf of 

 Mexico, respectively. A Draft Environmental Impact 

 Statement on the proposed sales was circulated to the 

 Commission and others for comment. The Statement 

 listed 28 species of cetaceans, the West Indian mana- 

 tee, and California sea lions as occurring in the 

 northern Gulf of Mexico. Six of the cetacean species 

 (the right, blue, sei, fin, humpback, and sperm 

 whales) are listed as endangered under the Endangered 

 Species Act. Of these, only sperm, fin, and sei 

 whales have been seen in the proposed lease sale areas 

 in recent years. 



In its Draft Statement, the Service estimated that, 

 under the base case scenario, most marine mammals 

 likely would be affected to an extent that complete 

 recovery to pre-lease conditions would occur within 

 one or two generations. Considering cumulative 

 effects of the proposed sale and other ongoing or 

 proposed activities, the Service concluded that impacts 



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