The 2002 eastern Bering Sea upper continental slope survey of groundfish and invertebrate resources

Abstract

The results of the 2002 Alaska Fisheries Science Centers’ (AFSC) bottom trawl survey of the groundfish and invertebrate resources of the eastern Bering Sea upper continental slope (Alaska) is presented.

The 2002 survey is the first biennial groundfish survey standardized to the AFSC’s latest technologies and protocols for survey design, net design, catch data gathering, species identification and recognition, and net mensuration monitoring.

One hundred and fifty-six tows were conducted from 200 to 1,500 m on the slope with 141 tows being successful (200-1,200 m) and used for abundance estimates. The survey area stretched from north of the Aleutian Islands, Alaska, at 54° N to near the Russian-U.S. border at 61° N. Sampling was stratified by six subareas running north to south and by five depth strata within each subarea. Target sampling effort was proportional to the subareas and depth strata and an average tow represented approximately 255 km2.

Presented are biomass in metric tons (t), population, and catch per unit effort (CPUE; no./ha and kg/ha) for all species identified on the survey. Size frequencies (33 species) and CPUE distribution (40 species) plots are presented for the most abundant or for species of commercial and ecological interest.

The largest fish species biomass encountered during the 2002 slope survey included giant grenadier (Albatrossia pectoralis), Pacific ocean perch (Sebastes alutus), and popeye grenadier (Coryphaenoides cinereus). The largest biomass of invertebrates encountered was the triangle Tanner crab (Chionoecetes angulatus).


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