MARINE MAMMAL COMMISSION - Annua] Report for 1998 



peds in certain instances. Section 120 also directs the 

 Service to investigate the impacts of growing sea lion 

 and harbor seal populations on the recovery of sal- 

 monid stocks and on coastal ecosystems in Washing- 

 ton, Oregon, and California, and to establish a task 

 force to examine problems involving pinnipeds and 

 aquaculture projects in the Gulf of Maine. 



The new regime includes a mechanism for autho- 

 rizing a limited incidental take of marine mammals 

 listed as endangered or threatened under the Endan- 

 gered Species Act, something the original statute and 

 the interim exemption did not provide. Such authori- 

 zations may be issued under section 101(a)(5)(E), 

 provided the National Marine Fisheries Service (or the 

 Fish and Wildlife Service for manatees and southern 

 sea otters) determines that (1) the incidental mortality 

 and serious injury will have a negligible impact on the 

 species or stock, (2) a recovery plan has been or is 

 being developed under the Endangered Species Act, 

 and (3) if required, a monitoring program for relevant 

 fisheries has been established under section 118. 



Actions involving the preparation of stock assess- 

 ments and take reduction plans are discussed in this 

 section and, as they relate to specific marine mammal 

 stocks, in Chapter II. Implementation of the other 

 requirements of section 118 and provisions applicable 

 to endangered and threatened species and deterring 

 marine mammals from damaging fishing gear or catch 

 are also discussed in this section. Actions taken under 

 section 120 are discussed in the section on pinniped- 

 fisheries interactions later in this chapter. 



Stock Assessments 



Section 117 of the Marine Mammal Protection Act 

 requires the Secretaries of Commerce and the Interior 

 to prepare and periodically update stock assessment 

 reports for each marine mammal stock that occurs in 

 U.S. waters. This provision also requires that three 

 regional scientific review groups be established to 

 assist in the development of these reports. These 

 groups were established in 1994 for Alaska, the 

 Pacific coast, including Hawaii, and the Atlantic 

 coast, including the Gulf of Mexico. They include 

 experts in marine mammal biology, commercial 

 fishing technology and practices, and, in the case of 

 Alaska, Native subsistence uses. Among other things, 



scientific review groups are to advise the Secretaries 

 on (1) the estimated size, status, and trends of marine 

 mammal stocks, (2) uncertainties and research needs 

 regarding stock separation, abundance, and trends, (3) 

 research on modifications in fishing gear and practices 

 to reduce the incidental mortality and serious injury of 

 marine mammals, and (4) potential impacts of habitat 

 destruction on marine mammals and, for strategic 

 stocks, conservation measures to reduce such impacts. 



Based on the advice of the regional groups and 

 public comment on draft stock assessments, the 

 Secretaries are to publish a final assessment report for 

 each stock. The Act directs that each assessment 



• describe the geographic range of the stock; 



• provide a minimum population estimate, the 

 stock's current and maximum net productivity 

 rates, and current population trend, including the 

 basis for those findings; 



• estimate the annual human-caused mortality and 

 serious injury, by source, and, for stocks deter- 

 mined to be strategic stocks, describe other factors 

 that may be causing a decline or impeding recov- 

 ery; 



• describe the commercial fisheries that interact with 

 the stock, including estimates of fishery-specific 

 mortality and serious injury levels and rates, a de- 

 scription of seasonal or area differences in inciden- 

 tal take, and an analysis of whether incidental-take 

 levels are approaching a zero mortality and serious 

 injury rate; 



• assess whether the level of human-caused mortality 

 and serious injury would cause the stock to be 

 reduced below its optimum sustainable population 

 or, alternatively, whether the stock should be 

 categorized as a strategic stock; and 



• estimate the potential biological removal level for 

 the stock. 



As defined in the Act, a stock's potential biological 

 removal level is the maximum number of animals, not 

 including natural mortality, that can be removed from 

 the stock while allowing the stock to reach or remain 

 at its optimum sustainable population level. The 

 potential biological removal level is calculated by 

 multiplying three variables — the minimum population 

 estimate for the stock, one-half of the theoretical or 

 estimated maximum net productivity rate of the stock 



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