CHAPTER VII 



INCIDENTAL TAKE OF MARINE MAMMALS IN THE COURSE 

 OF COMMERCIAL FISHING OPERATIONS 



The Marine Mammal Protection Act directs the Secretaries 

 of Commerce and the Interior, in consultation with the Commis- 

 sion, to develop regulations governing the incidental taking 

 of marine mammals by persons subject to the jurisdiction of 

 the United States. It also calls upon the Secretaries, again 

 in consultation with the Commission, to develop effective 

 international arrangements, through the Secretary of State, 

 for the purpose of reducing the incidental taking of marine 

 mammals to insignificant levels approaching a zero mortality 

 and serious injury rate. 



Although the incidental taking of marine mammals occurs 

 in the course of many fisheries and involves many different 

 species of marine mammals, the "tuna-porpoise" issue involving 

 the incidental mortality and serious injury of porpoises 

 entrapped in purse seine nets used by commercial yellowfin 

 tuna fishermen has, over the past decade, been the subject of 

 the most intense concern, attention, and controversy. More 

 recently, there has been concern over the incidental taking 

 of Dall's porpoises and other marine mammals in the course of 

 the Japanese salmon gill net fishery in the North Pacific 

 Ocean, a portion of which occurs within the United States' 

 200-mile Fishery Conservation Zone. The Commission's activities 

 during 1988 related to the tuna-porpoise and Dall's porpoise 

 issues are discussed below. Interactions between fisheries 

 and other marine mammals are discussed in Chapter VIII. 



The Tuna-Porpoise Issue 



Discussions of the Commission's past activities and a 

 historical summary of the efforts to resolve the tuna-porpoise 

 problem are presented in previous Annual Reports. As discussed 

 below, the Commission, the National Marine Fisheries Service, 

 the U.S. Congress, the U.S. tuna industry, and others continued 

 to devote substantial attention to the issue in 1988. In 

 1986, the U.S. tuna fleet reached the incidental kill quota 

 of 20,500 porpoises in mid-October. As a result, the U.S. 

 tuna purse seine fleet was prohibited from fishing for tuna 

 by setting on marine mammals for the remainder of the year. 

 The level of marine mammal mortality observed in 1987 was 

 considerably lower than that for 1986 and there was no need 

 to prohibit setting on porpoise in 1987. The mortality of 

 eastern spinner dolphins, however, was unusually high and 

 necessitated close monitoring to ensure that the allowable 

 level of take of 2,750 would not be exceeded. 



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