MARINE MAMMAL COMMISSION — Annual Report for 1995 



illegal fillets, and otherwise assist in stopping possible 

 transport of totoaba fillets. No fillets were seized. 



The Fisheries Service also is making efforts to 

 educate U.S. travellers entering Mexico about the 

 illegality of catching or transporting totoaba. In 1993 

 the Service developed a brochure for tourists that 

 describes the distribution and external features of the 

 totoaba and the vaquita and discusses the prohibitions 

 regarding their capture or transport. Several thousand 

 copies were distributed in 1993. The brochure was 

 reprinted in 1994, and in 1994 and 1995 the Service 

 distributed copies to tourists entering Mexico and 

 other interested parties. 



The Commission is encouraged by actions taken by 

 the Government of Mexico and others to conserve the 

 vaquita and its habitat. However, it is not clear if 

 everything possible is being done to recover the 

 species. The Commission, in consultation with its 

 Committee of Scientific Advisors, will continue to 

 track activities related to the conservation of this 

 species. 



Gulf of Maine/Bay of Fundy 



Harbor Porpoise 



(Phocoena phocoena) 



Harbor porpoises, measuring less than two meters 

 in length, are among the smallest cetaceans. They 

 occur in coastal temperate and boreal waters only in 

 the Northern Hemisphere, and feed on a variety of 

 small schooling fishes, such as herring, silver hake, 

 and capelin. The species is prone to becoming 

 entangled in gillnets and, because its coastal distribu- 

 tion off New England overlaps major gillnet fishing 

 grounds whose target species, groundfish, also feed on 

 the same prey species, incidental catch of harbor 

 porpoises in gillnets is a significant conservation 

 problem in that area. 



Harbor porpoises appear to occur in discrete stocks 

 whose boundaries and geographic ranges generally are 

 not well known. Along the east coasts of the United 

 States and Canada, however, harbor porpoises have 

 been comparatively well studied. The studies suggest 

 a single migratory stock of animals exists from the 



Bay of Fundy in Canada south to North Carolina, the 

 southern limit of the species' normal range in the 

 western North Atlantic. It is known as the Gulf of 

 Maine/Bay of Fundy harbor porpoise stock because it 

 concentrates in those areas in summer. During spring 

 and fall, this stock disperses between the Bay of 

 Fundy and North Carolina. Its distribution in winter 

 is mostly unknown. Harbor porpoises also occur in 

 Canada north of the Bay of Fundy and off southern 

 Greenland, but porpoise in those areas are not thought 

 to part of the same stock. 



Many species of marine mammals are taken 

 incidental to commercial fishing in the United States; 

 however, the largest cetacean bycatch in recent years 

 has been the take of harbor porpoises in a sink gillnet 

 fishery for groundfish off New England. Harbor 

 porpoises from the same stock also are taken by sink 

 gillnets in the Bay of Fundy in Canada and by coastal 

 gillnets south of New England. A subjective analysis 

 by Canadian scientists combining anecdotal informa- 

 tion and very limited catch data suggested that early 

 in the 1980s perhaps 600 porpoises a year were being 

 taken in the Bay of Fundy, the Gulf of Maine, and 

 more southern waters, and that take in commercial 

 fisheries may have been affecting the regional harbor 

 porpoise stock since the 1970s. A study comparing 

 body lengths of porpoises collected in 1969-1973 with 

 those taken in 1981-1986 found that, while calves 

 tended to be larger in the latter period, the overall 

 population was composed of smaller animals. This 

 suggested that individuals were not surviving to older 

 ages, that calf-bearing periods of mature females were 

 becoming shorter, and that food was not a limiting 

 factor. 



In an effort to reduce the incidental take of marine 

 mammals in commercial fisheries, Congress amended 

 the Marine Mammal Protection Act in 1988. In part, 

 the amendments require that the National Marine 

 Fisheries Service establish an observer program to 

 assess and monitor incidental-take levels in U.S. 

 fisheries. Observer sampling in the New England 

 sink gillnet fishery for groundfish began in 1990. 

 Based on the levels of observed take of harbor por- 

 poises in that sampling program and estimates of total 

 fishing effort from port-based landing reports, the 

 Service estimated that harbor porpoise incidental-take 

 levels in the New England sink gillnet fishery was 



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