Alaska Longline Survey
The Alaska Fisheries Science Center conducts annual longline surveys to estimate the relative abundance of major groundfish species on the continental slope of the eastern Bering Sea, Aleutian Islands, and the Gulf of Alaska. The survey is primarily designed to assess sablefish and indices of abundance have been computed since 1979. Catch data from other species are also available. From 1979 to 1994, the Center conducted cooperative annual longline surveys with Japan, and then independently from 1987 to present.
Data is available from annual bottom longline surveys conducted cooperatively by Japan (1979-1994) and the NOAA Fisheries' Alaska Fisheries Science Center (1988-present). Stations are spaced systematically (~20-30 km apart) along the slope from the eastern Gulf of Alaska west to the Aleutian Islands and north into the eastern Bering Sea. At each station, depths from ~150-1000 meters are sampled. The same stations are sampled each year except in the Aleutian Islands and the Bering Sea, which are sampled every other year at the beginning of the survey (last week of May-early June). Since 1995, in odd years the Bering Sea stations are sampled and in even years the Aleutian Islands are sampled. The status of each hook is recorded. Lengths are taken from major species including, sablefish, giant grenadier, Pacific grenadier, Greenland turbot, arrowtooth flounder, Pacific cod, shortspine thornyhead, and all rockfish caught.