Chapter HI — Species of Special Concern 



2,900 porpoises in 1990, 2,000 porpoises in 1991, 

 1,200 porpoises in 1992, and 1,400 porpoises in 

 1993. As discussed below, the observer program was 

 continued in 1994 and 1995 but, due to changes in the 

 way the Service tracked fishing effort and other 

 problems, estimates of total incidental take for the 

 fishery in those years were not yet available at the end 

 of 1995. Partial analyses in 1995, however, suggest 

 that incidental take in 1994 increased substantially 

 above the 1992 and 1993 levels. 



The incidental catch of harbor porpoises in the 

 Canadian gillnet fishery in the Bay of Fundy also has 

 been a concern, but until recently reliable data on take 

 levels from that area have not been available. In 1993 

 and 1994 the Canadian Department of Fisheries and 

 Oceans carried out an observer program to assess 

 harbor porpoise take in the Bay of Fundy in Canada. 

 Based on results for those years, incidental take by 

 gillnets in that area has been estimated at 424 porpois- 

 es in 1993 and 101 porpoises in 1994. Almost all of 

 the porpoises were taken in two small areas in sum- 

 mer and early fall. Adding together the 1993 catch 

 estimates for Canadian and New England waters 

 suggests a total take of more than 1,800 animals in the 

 northern end of the range of the Gulf of Maine/Bay of 

 Fundy harbor porpoise stock in that year. 



Information on incidental take of harbor porpoises 

 between New York and North Carolina is based on 

 stranded porpoises exhibiting marks from gillnets or 

 attached net fragments. In 1993, 50 harbor porpoises 

 were found stranded in this area, mostly in Virginia 

 and North Carolina between March and May, and 

 several animals showed signs of gillnet interactions. 

 In 1994 the number of harbor porpoise strandings in 

 the area increased. As of the end of 1995 information 

 was not yet available on the number of strandings 

 showing evidence of gillnet interactions or the number 

 of strandings in 1995. 



The source of these interactions is unclear. Coastal 

 gillnetters fishing between New York and North 

 Carolina target various fish species depending on 

 location and season. In recent years many gillnet 

 fishermen from the northeastern United States also 

 have begun fishing in this area for dogfish and monk- 

 fish. They often operate from small boats on sched- 

 ules that make observer programs difficult. Although 



gillnet fishery observers in this region have not yet 

 identified the fishery responsible for harbor porpoise 

 strandings, a coastal shad fishery that has not yet been 

 studied may be involved. 



The high number of porpoises caught in gillnets off 

 New England prompted the National Marine Fisheries 

 Service to conduct harbor porpoise surveys in 1991 

 and 1992 to estimate stock size. The surveys were 

 carried out in the summer when the stock is concen- 

 trated in the northern part of its range, and they 

 produced stock size estimates of 37,500 animals (95% 

 confidence interval 26,700 to 86,400) from 1991 data, 

 and 67,500 animals (95% confidence interval 32,900 

 to 104,600) from 1992 data. Pooling the results gives 

 a weighted stock size estimate of 47,200 animals 

 (95% confidence interval 39,500 to 70,600). Al- 

 though a new survey was conducted in the summer of 

 1995, analyses had not yet been completed as of the 

 end of 1995. 



Given estimates of stock size, harbor porpoise 

 reproductive biology, and other information, it seems 

 likely that incidental-take levels from the Gulf of 

 Maine/Bay of Fundy harbor porpoise stock have 

 exceeded sustainable levels. 



Gulf of Maine/Bay of Fundy 

 Harbor Porpoise Stock Assessment 



In 1994 the Marine Mammal Protection Act was 

 amended to require that the National Marine Fisheries 

 Service develop marine mammal stock assessments to 

 help manage the incidental take of marine mammals in 

 U.S. fisheries (see also Chapter IV). The assessments 

 are to include estimates of stock size, maximum net 

 productivity, and a potential biological removal level 

 (other than natural mortality) that would allow the 

 stock to increase to or remain within optimum popula- 

 tion limits. The assessments also are to include a 

 determination as to whether a stock should be consid- 

 ered "strategic," which could trigger the formation of 

 an incidental-take reduction team to prepare an 

 incidental-take reduction plan. 



The Service circulated the draft stock assessments 

 in August 1994. In its 12 December 1994 comments 

 on the draft assessments, the Commission noted that 



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