Chapter II — Species of Special Concern 



minimum diameter of twine used for net webbing. 

 They also include requirements for tie-downs {i.e., 

 tying floatlines and leadlines together to minimize the 

 vertical height of the net) and affixing identification 

 tags to nets. With these measures, the Service pro- 

 jected that bycatch levels in the mid-Atlantic area 

 would be reduced by 79 percent. Based on an aver- 

 age annual bycatch estimate of 207 for 1995 and 

 1996, it projected that bycatch in the mid- Atlantic 

 area would be reduced to 50 per year. 



The proposed plan also included several non- 

 regulatory provisions. These include a mandatory 

 training program on the use and maintenance of 

 pingers; efforts to randomly check pingers for their 

 functional reliability; the development of hydrophones 

 for enforcement officers to help ensure that deployed 

 nets are equipped with functioning pingers; studies to 

 assess the possibility that porpoises may habituate to 

 pinger sound (thereby reducing the effectiveness of 

 pingers); smdies of the effects of pinger sounds on 

 other ecosystem components; efforts to make bycatch 

 estimates available in a more timely manner; and an 

 expanded observer program for the mid- Atlantic area. 



The Commission provided comments on the 

 proposed plan to the Service on 13 October 1998. In 

 its letter, the Commission noted that the new proposal 

 incorporated important new features, such as take 

 reduction measures for the mid-Atlantic area, mea- 

 sures to expand the use of pingers off New England, 

 and the implementation of relevant rules under provi- 

 sions of the Marine Mammal Protection Act rather 

 than fishery management plans. The Commission 

 concluded that the rules should contribute substantially 

 to reducing the harbor porpoise bycatch. 



The Commission also noted, however, that some 

 assumptions used by the Service to predict expected 

 bycatch levels under the proposed plan were overly 

 optimistic. For example, it noted that available 

 pingers require a level of maintenance difficult to 

 provide in commercial operations and that experience 

 to date with their use in commercial operations 

 suggests that porpoise bycatch would be reduced 50 

 percent or less in some times and areas. Thus, it did 

 not seem reasonable to expect that pingers, at least in 

 the initial year of broadscale use, would achieve an 80 

 percent reduction in bycatch in all areas. In addition. 



the Commission noted that time-area restrictions have 

 often displaced fishing effort and associated bycatch to 

 surrounding areas and times. The plan did not 

 account for such shifts in predicting future bycatch 

 estimates. Further, the Commission noted that 

 bycatch estimates for the mid-Atlantic area were based 

 on questionable assumptions that almost certainly 

 underestimated bycatch in that area. Thus, the 

 Service was underestimating bycatch reduction needs 

 for the mid-Atlantic area. 



Therefore, the Commission recommended that the 

 Service use a more conservative estimate of the likely 

 effectiveness of pingers and reexamine the accuracy of 

 the mid-Atlantic area bycatch estimates used as the 

 basis for developing its plan. Noting the need to 

 offset higher bycatch levels given its reduced expecta- 

 tions for the initial effectiveness of pingers, the 

 Commission recommended that the Service replace its 

 complex system of time-area management zones for 

 pingers with a blanket provision requiring that pingers 

 be used on all gillnets in all times and areas off New 

 England except Massachusetts Bay and south of Cape 

 Cod in summer when harbor porpoises are unlikely to 

 occur in those areas. Doing so, the Commission 

 noted, would increase the level of bycatch reduction 

 realized by using pingers, simplify the regulations, 

 and facilitate enforcement. With regard to enforce- 

 ment, the Commission noted that, by requiring all 

 gillnets to be equipped at all times with functioning 

 pingers, it would be possible to check for properly 

 functioning pingers in port as well as on fishing 

 grounds. If a blanket requirement for using pingers 

 still was insufficient to reduce projected bycatch below 

 the potential biological removal level, the Commission 

 recommended that the Service reconsider a provision 

 recommended by the Gulf of Maine team, but not 

 adopted by the Service, to close an area between 

 northeastern Massachusetts and southern Maine to all 

 gillnet fishing during March. 



On 2 December 1998 the Service published final 

 rules in the Federal Register to implement the regula- 

 tory portions of its harbor porpoise take reduction 

 plan. Although the final rule included some changes, 

 they did not differ significantly from the proposed 

 measures. For the New England area, the Service 

 retained its approach of overlaying new time-area 

 management zones (i.e., for fishing closures and 



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