Distribution, Abundance and Behavior of Endangered Whales in the Alaskan Chukchi and Western Beaufort Sea, 1989

摘要

The report summarizes the 1989 investigations of the distribution, abundance, migration timing and route, behavior, and habitat relationships of endangered whales in the Alaskan Chukchi and western Beaufort Sea (hereafter, study area); 1989 was the first year of a 3-year (1989-91) study. Data were collected during transect and search surveys flown in a specially modified Grumman Goose (model G21G) aircraft over the study area from 20 September through 3 November. The Bering Sea stock of bowhead whales (Balaena mysticetus) was the principal species studies. Gray whales (Eschrichtius robustus) were also studied, with incidental sightings of all other marine mammals routinely recorded. Data collected during the 1989 study were subsequently integrated with the results of surveys conducted from 1980-88. In 1989, there were 69 sightings of 131 bowhead whales and 59 sightings of 170 gray whales in the study area from 20 September through October. Over 8 survey seasons (1982-89) there were 226 sightings of 501 bowhead whales and 137 sightings of 397 gray whales. Bowheads were seen from 18 September (1983) to 29 October (1989), with ca. 10-day oscillations in daily sighting rate suggesting that whales migrate in pulses.