Questions concerning the methodology that should be used 

 to estimate porpoise mortality were raised by the Commission 

 and others in 1986. As a result of deliberations among the 

 National Marine Fisheries Service, the Commission, and other 

 interested parties, it was determined that the same methodology 

 that had been used previously would be used in 1987, but that 

 further review of alternative approaches would take place. 

 In addition, the Service decided to provide 100 percent observer 

 coverage for the first trip of the U.S. tuna fleet in 1987. 

 In response to comments from the tuna industry that the metho- 

 dology being used to estimate porpoise mortality tended to 

 overestimate the true level of kill and that the 1986 season 

 was closed prematurely, the Service initiated a study of the 

 issue and set a target of 100 percent observer coverage through- 

 out the 1987 season. The Service has reviewed the data from 

 the 1987 season to better determine the optimal level of 

 observer coverage and has prepared a draft report of its 

 findings. A final report of the study is expected to be 

 issued early in 1989. 



The 1988 amendments to the Marine Mammal Protection Act, 

 discussed in Chapter II, addressed the issue of observer 

 coverage in the tuna fleet, at least in the near term. Under 

 the amendments, the Service is reguired to place an observer 

 on board each certificated vessel for all trips during 1989 

 and subseguent years unless, for reasons beyond the Service's 

 control, an observer is not available. The 100 percent observer 

 reguirement may be waived after the 1991 fishing season if 

 the Service determines, after notice and opportunity for 

 public comment, that lesser coverage will provide sufficiently 

 reliable information. 



As noted previously, the Service published emergency 

 interim regulations in 1986 that imposed a ban on catching, 

 possessing, or landing yellowfin or bigeye tuna from the 

 eastern tropical Pacific Ocean once the porpoise guota had 

 been reached. An exception to the ban was established for 

 vessels that voluntarily carried a National Marine Fisheries 

 Service observer to verify compliance with the prohibition on 

 fishing on porpoise. By letter of 3 October 1986, the Commis- 

 sion supported the adoption of the regulations and recommended 

 that permanent regulations including similar requirements be 

 established for future fishing seasons. The emergency regula- 

 tions went into effect on 21 October 1986, and no additional 

 takes of porpoise were reported for that year. On 23 December 

 1986, the Commission again recommended that the Service adopt 

 permanent regulations to enforce the guota. At the close of 

 1988, no such regulations had been proposed by the Service. 



At the end of 1986, the Service took the first step 

 toward establishing regulations that would govern the perfor- 

 mance of individual vessels and/or captains in the U.S. tuna 



151 



