MARINE MAMMAL COMMISSION - Annual Report for 1998 



Efforts to reduce the incidental mortality of dolphins 

 in this fishery have been a primary focus of the 

 Marine Mammal Protection Act since it was enacted 

 in 1972. 



Background 



The eastern tropical Pacific tuna fishery was domi- 

 nated by U.S. vessels during the 1960s and early 

 1970s. In the late 1970s and early 1980s the U.S. 

 fleet declined and the number of foreign vessels 

 participating in the fishery grew. Along with these 

 shifts in the fishery came changes in the associated 

 dolphin mortality. As reflected by mortality data 

 presented in Table 10, progress made by the United 

 States to reduce dolphin mortality under the Marine 

 Mammal Protection Act was offset by increased 

 mortality from growing foreign operations. This 

 prompted Congress to amend the Marine Mammal 

 Protection Act in 1984 and again in 1988 to establish 

 comparability requirements for nations seeking to 

 export tuna to the United States. Imports of yellowfin 

 tuna caught in the eastern tropical Pacific were banned 

 from countries that failed to adopt a tuna-dolphin 

 program comparable to that of the United States or 

 whose fleet exceeded the incidental-take rate of the 

 U.S. fleet by a certain amount. In addition, imports 

 of yellowfin tuna from intermediary nations that 

 imported tuna from nations subject to a primary 

 embargo were made subject to a secondary embargo. 

 In an effort to reduce dolphin mortality further, 

 additional requirements also were placed on U.S. tuna 

 fishermen. 



The requirements enacted in 1988 and the threat of 

 tuna embargoes resulted in substantially reduced 

 dolphin mortality by foreign fleets. Another factor 

 contributing to the drop in dolphin mortality was the 

 La Jolla Agreement, an agreement entered into 

 voluntarily by the tuna-fishing nations in 1992, which, 

 among other things, established vessel-specific mortal- 

 ity limits. Under these requirements, dolphin mortali- 

 ty declined by more than 95 percent between 1988 

 and 1993. Although part of this decline is attributable 

 to a smaller number of sets being made on dolphins, 

 the primary factor in reducing incidental dolphin 

 mortality has been a marked reduction in the average 

 number of dolphins killed per set. 



Table 10. Estimated incidental kill of dolphins in 

 the tuna purse seine fishery in the 

 eastern tropical Paciflc Ocean, 

 1972-1998' 



These estimates, based on kill per set and fishing effort data, 

 are provided by the National Marine Fisheries Service and the 

 Inter-American Tropical Tuna Commission. They include 

 some, but not all, seriously injured animals released alive. 

 Preliminary estimate. 



Preliminary data suggest that dolphin mortality 

 incidental to the eastern tropical Pacific tuna fishery 

 in 1998 declined to a record low level. Although the 

 Inter-American Tropical Tuna Commission is still 

 collecting and analyzing data from 1998, it expects 

 that incidental dolphin mortality for the year will be 



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