IMIS

Purpose: Although harbor porpoises, Phocoena phocoena, are known to occur throughout Alaska waters, few estimates of abundance exist. In 1991, the National Marine Mammal Laboratory initiated a 3-yr study on Alaska harbor porpoises. The objectives of this program were to: 1) Obtain minimum population estimates in coastal waters using line transect methodology with a coefficient of variation for density estimates of less than 30% for each survey area, and 2) Establish a baseline for detecting changes in abundance through time, for analysis of trends. Supplemental information: 9/8/2005: This dataset and associated effort data were updated. Those who downloaded them before that date should renew them. The ability of the observers to sight porpoise was sensitive to environmental conditions. As expected, when conditions deteriorated the number of porpoises observed declined.