NOAA Technical Memorandum
NMFS-AFSC-138
Compilation of marine mammal incidental take data from the domestic and joint venture groundfish fisheries in the U.S. EEZ of the North Pacific, 1989-2001
Abstract
This report presents a compilation by species, year, area, and gear type (trawl, longline, pot, and jig) of observer data on incidental take by the domestic (1989-2001) and joint venture (1989-1990) groundfish fisheries in the U.S. Exclusive Economic Zone of Alaska and the U.S. West Coast. Nineteen species of marine mammals (276 individuals) were observed killed or injured. Four of these 19 marine mammal species are classified as endangered under the Endangered Species Act : the western population only of the Steller sea lion (Eumetopias jubatus), the humpback whale (Megaptera novaeangliae), the fin whale (Balaenoptera physalus), and the sperm whale (Physeter macrocephalus). Sperm whales were not killed in groundfish gear, but two sperm whales were considered seriously injured after becoming entangled in and released with trailing longline gear. The only take recorded for the jig fishery was one Dall's porpoise (Phocoenoides dalli) entangled in the lines and released with trailing gear; no marine mammals were directly killed by jig gear. Thirteen individual marine mammals sustained minor injuries before being returned to the sea, and 26 other individuals returned to the sea unharmed after either being caught by the gear or boarding the vessel of their own volition .
Sea otters (Enhydra lutris) were reported killed in the groundfish fisheries only by pot gear, and only in 1992 . Stratified random sampling ratio estimates were used to calculate total bycatch . The at-sea Pacific whiting trawl fishery off the coasts of Washington, Oregon, and California was estimated to have incidentally caught and killed a total of 44 marine mammals between 1990 and 2001. In Alaska, the domestic trawl fishery was estimated to have incidentally killed a total of 445 marine mammals during the years from 1989 to 2001 . The estimated average annual bycatch of Steller sea lions by the domestic trawl fisheries in Alaska during 1990-2001 was about 10% of the level of the average annual estimated take (127 sea lions) by the joint venture fisheries in Alaska during 1985-1989.
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