Species Identification Confidence in the Gulf of Alaska and Aleutian Islands Surveys (1980-2011)
April 24, 2018
The quality and specificity of field identifications for many taxa have fluctuated over the history of the surveys due to changing priorities and resources. Historical trends in identification quality for each of the major Alaska Fisheries Science Center bottom trawl surveys was documented. These reports include identification confidence matrices for all fish and invertebrates identified from respective surveys.
The Resource Assessment and Conservation Engineering (RACE) Division of the Alaska Fisheries Science Center (AFSC) has been conducting bottom trawl surveys of the continental shelf and upper slope of the Gulf of Alaska (GOA) and Aleutian Islands (AI) since 1980. Both surveys were conducted triennially from 1980 until after 1999 in the GOA and after 2000 in the AI, when both became biennial surveys. A stratified random design is used in station selection to conduct standardized trawling operations (Stauffer 2004) in trawlable areas to depths of 500 m in the AI and down to 1,000 m in the GOA (von Szalay et al. 2010, 2011). Since 1980 the AI survey has averaged about 450 successfully completed trawls, while the GOA survey has averaged about 850 trawls per survey. Data gathered from the summer surveys are stored in an AFSC Oracle™ database (RACEBase) and are used for fisheries-independent assessments of population trends that inform stock assessments used to develop management strategies for commercially exploited fish and invertebrates in these regions. In addition to their utility for making fisheries management decisions, data collected during these surveys have been used by a variety of constituents to examine spatial and temporal trends in the fish and invertebrate fauna of the Alaska region.