MARINE MAMMAL COMMISSION — Annual Report for 1991 



could be very high, primarily due to the effects of 

 large oil spills, and that such effects might result in 

 the complete loss of a regional population and require 

 three or more generations to recover to pre-lease 

 conditions. 



The Commission, in consultation with its Commit- 

 tee of Scientific Advisors, reviewed the Draft State- 

 ment and provided comments on 18 June 1991. In its 

 letter, the Commission noted that, although the 

 conclusions regarding estimated impacts on marine 

 mammals may be valid, the Draft Statement generally 

 did not provide data, analyses, or references to 

 support them. For example, the Draft Statement 

 stated that production waters and drilling muds would 

 dissipate so rapidly that they would not affect marine 

 mammal food supplies. However, it provided no 

 information on marine mammal diet, feeding areas or 

 food requirements. 



The Commission therefore concluded that the Draft 

 Statement did not provide a sufficiently thorough 

 assessment of the proposed action's possible impacts 

 on marine manmials in the sale area. In its letter, the 

 Commission suggested that the Statement be expanded 

 to provide a more thorough assessment of the possible 

 indirect food chain effects, as well as the possible 

 direct effects on marine mammals, particularly endan- 

 gered sperm whales and local populations of bottle- 

 nose dolphins. 



As a minimum, the Commission recommended that 

 critical uncertainties, research needs, and recommen- 

 dations identified at an August 1989 Minerals Man- 

 agement Service-sponsored Workshop on Sea Turtles 

 and Marine Mammals of the Gulf of Mexico be 

 considered and incorporated into the Statement. In 

 addition, the Commission recommended that, if it had 

 not already done so, the Service consult the National 

 Marine Fisheries Service to (a) obtain the most up-to- 

 date information on the distribution, abundance, 

 population structure, diet, and important calv- 

 ing/breeding/feeding areas of sperm whales, bottle- 

 nose dolphins, and other marine mammals common to 

 the northern Gulf of Mexico and (b) ascertain the 

 types of site-specific and population monitoring 

 programs needed to ensure that marine mammals and 

 their habitats are not adversely affected by offshore oil 

 and gas activities in the northern Gulf of Mexico. 



Proposed Offshore Lease Sale, 

 Cook Inlet, Alaska 



By letter of 17 June 1991, the Minerals Manage- 

 ment Service advised the Commission and other 

 agencies and organizations that it was considering a 

 potential offshore gas and oil lease sale in the Cook 

 Inlet area off south-central Alaska. In its letter, the 

 Service requested help in updating biological, socio- 

 cultural, oceanographic, and geologic information 

 concerning the area. The Service also noted its 

 intention to hold an information transfer meeting early 

 in 1992 for the Gulf of Alaska/Cook Inlet and Bering 

 Sea areas. 



In its 3 July 1991 response, the Commission 

 forwarded a number of documents bearing on the 

 assessment of possible impacts of offshore oil and gas 

 activities on marine mammals in the Cook Inlet area. 

 In its letter of transmittal, the Commission noted that 

 a variety of marine mammals occur in the Cook Inlet 

 and Shelikof Strait area and that species of greatest 

 concern are the northern right whale, the Steller sea 

 lion, the beluga whale, the harbor seal, and the sea 

 otter. The North Pacific right whale population may 

 number only a few animals and is probably near 

 extinction. The Steller sea lion population has de- 

 clined dramatically throughout most of its range 

 during the past 20 years, and has been listed as 

 threatened under the Endangered Species Act. 



Therefore, the Commission recommended that, if 

 it had not already been done, the Minerals Manage- 

 ment Service inmiediately consult the National Marine 

 Fisheries Service pursuant to section 7 of the Endan- 

 gered Species Act to determine whether exploration, 

 development, or related support activities in or near 

 areas being considered for leasing could jeopardize, the 

 continued existence of any endangered or threatened 

 species, particularly the right whale and the Steller sea 

 lion. 



Very little is known about the distribution, move- 

 ments, habitat requirements, or essential habitats of 

 marine mammals in the Cook Inlet area. However, it 

 is possible that substantial numbers of some species 

 (e.g., killer whales and harbor porpoise) are killed 

 incidentally in commercial fisheries. Therefore, in its 



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