As indicated in past Annual Reports, there appears to have been a worldwide 

 increase in unusual marine mammal mortality events since the late 1970s. More 

 occurred in 1991. While the reasons for the apparent increase are not clear, the increase 

 may be due, at least in part, to environmental pollution or other factors that suppress the 

 immune systems and weaken the ability of marine mammals to ward off natural disease. 

 This issue, of great concern to the Commission, is discussed in Chapter V. 



Marine mammals and other species, including some that are endangered, are killed 

 or injured as a result of becoming entangled in or ingesting lost or discarded nets, line, 

 and other debris. Such debris is now recognized as a major form of marine pollution and 

 a serious threat to many species. As discussed in Chapter VI, the Commission continued 

 in 1991 to help the National Marine Fisheries Service in its efforts to carry out 

 education, mitigation, and research activities through the Marine Entanglement Research 

 Program. In cooperation with the Coast Guard and the National Marine Fisheries 

 Service, the Commission also helped focus attention on implementing the provisions of 

 Annex V of the International Convention for the Prevention of Pollution from Ships, 

 which regulates disposal of ship-generated garbage. 



As noted in Chapter VII, marine mammal management in Alaska is particularly 

 challenging. This is due, in part, to the large numbers of marine mammals in Alaska, 

 their use for subsistence purposes by Alaska Natives, and interactions with commercial 

 fisheries and offshore oil and gas development. In 1991, the Commission took steps to 

 help the Fish and Wildlife Service and the National Marine Fisheries Service strengthen 

 their marine mammal programs in Alaska. Among other things, the Commission started 

 preparation of draft conservation plans for walruses, polar bears, and sea otters, and the 

 preparation of species accounts with research and management recommendations for 

 Steller sea lions, killer whales, and harbor seals. For reasons that are not known, 

 populations of a number of Alaska marine mammals and seabirds have declined 

 significantly in recent years. In December 1990, the Commission and the National 

 Marine Fisheries Service conducted a workshop to assess possible causes and 

 implications of these declines and related research and management needs. The 

 workshop report, completed and widely distributed in 1991, is among the matters 

 discussed in Chapter VII. 



The Minerals Management Service, the National Marine Fisheries Service, and the 

 Fish and Wildlife Service share responsibility for ensuring that activities and events, like 

 oil spills, associated with offshore oil, gas, and mineral exploration and development do 

 not have significant adverse effects on marine mammals or the ecosystems of which they 

 are a part. In 1991, these agencies, in consultation with the Commission, promulgated 

 regulations and took other actions, as described in Chapter VIE, to give effect to section 

 101(a)(5) of the Marine Mammal Protection Act. This section of the Act directs the 



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