Norton Sound Red King Crab Trawl Survey

The 1996 Norton Sound red king crab trawl survey was the first trawl survey of Norton Sound red king crabs to be conducted since the National Marine Fisheries Service (NMFS) performed their survey in 1991and it was the first trawl survey ever performed by ADF&G in Norton Sound. The stock assessment survey provided estimates of the Norton Sound red king crab population which are used by fishery managers.

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400 Eastern otter trawl used for the survey.

Trawl assessment surveys have been conducted in Norton Sound triennially from 1976 to 1991 by NMFS to provide distribution and abundance of demersal fish and invertebrates to fishery managers. Due to federal budgetary constraints, responsibility for future trawl surveys was transferred to the ADF&G.

In 1996 ADF&G surveyed a portion of Norton Sound for red king crabs and associated marine life for spatial distribution and abundance and population characteristics using a 400 eastern otter trawl. Population estimates of red king crabs were made from this data using the area-swept technique. Continuity with previous NMFS surveys was maintained by using the station midpoints, grid patterns, and general sampling procedures.

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Marine bycatch from the trawl.

The trawl survey occurred in a 12 day period from August 7-18, 1996. A total of 69 successful tows were made. There were 485 red king crabs captured. There were 113 taxa identified from the 69 tows which had a combined weight of 21,615 kg.

Fourteen of the top 20 taxa (ranked by weight) from the 1988 and 1991 NMFS and 1996 ADF&G Norton Sound trawl surveys were the same. Species of commercial value in Norton Sound may include: starry flounder, Pacific halibut, green sea urchin, walleye pollock, and various shrimp species.

The 1996 Norton Sound red king crab trawl survey. (Blau, S.F., L.J. Watson and J. Blackburn. 1996.)