Status of the harbour porpoise, Phocoena phocoena, in Canada

Abstract

No surveyed census estimates of population sizes are available in Canadian coastal waters other than for the Bay of Fundy-northern Gulf of Maine, which has a seasonal population of 4000-8000 animals, with a peak period of residency from late July to mid-September. This population, like those on the west coast, in the St. Lawrence and off Newfoundland, is believed to make a seasonal migration of a rather diffuse nature. Although generally regarded as a common species, it is evidently in decline in many parts of its total range. While factors such as increased human disturbance of coastal regions may be implicated in this decline and increased contamination of the environment may be another factor, the most likely reason for decreasing numbers is the toll exacted by incidental catches in fishing gear, especially groundfish gillnets, coupled with the animal's very limited reproductive flexibility. -from Author