Results of the 2010 Eastern Northern Bering Sea Continental Shelf Bottom Trawl Survey of Groundfish and Invertebrate Fauna.

摘要

From June to August 2010, the National Marine Fisheries Service's Alaska Fisheries Science Center, Resource Assessment and Conservation Engineering Division, conducted its 29th annual eastern Bering Sea (EBS) continental shelf bottom trawl survey of groundfish and invertebrate fauna. In addition, the 2010 survey coverage was expanded to include the northern Bering Sea (NBS). The expanded study area covered the entire Bering Sea continental shelf from 20 to 200 m bottom depth to the U. S.-Russian Convention Line between the Alaska Peninsula and the Bering Strait, including Norton Sound. Three stern trawlers, the 43.5-m FV Alaska Knight, the 40-m FV Aldebaran, and the 38-m FV Vesteraalen were chartered to sample this survey area. Demersal populations of fishes and invertebrates were sampled by trawling for 30 minutes at stations centered within a stratified systematic grid consisting of a total of 376 stations in the EBS and 145 stations in the NBS. At each station, species composition of the catch was determined, and length distributions and age structure samples were collected from ecologically and commercially important species. All survey stations were sampled successfully in the EBS, and all but three stations were sampled successfully in the NBS. For the fifth consecutive year, average surface (5.4 degrees C) and bottom (1.4 degrees C) water temperatures for the EBS shelf were well below the long-term means from 1982 to 2009 for the surface (6.6 degrees C) and for the bottom (2.3 degrees C). A total of 120 species of fishes representing 23 families and 74 genera, as well as 199 species of invertebrates representing 14 phyla, were identified in the catches from both the EBS and NBS. Fish taxa in the EBS accounted for 74% of the total CPUE compared with the NBS where fish taxa accounted for only 38% of the total CPUE. In the EBS, walleye pollock (Theragra chalcogramma), Pacific cod (Gadus macrocephalus), yellowfin sole (Limanda aspera), and rock sole (Lepidopsetta spp.) comprised 77% of the total fish biomass, and in the NBS, yellowfin sole and Alaska plaice (Pleuronectes quadrituberculatus) comprised 61% of the total fish biomass. The majority of invertebrate biomass in both the EBS (67%) and NBS (67%) consisted of echinoderms and crustaceans. Survey results presented herein include abundance estimates for fishes and invertebrates, geographic distributions and abundance-at-length of the more common fish species, and summary surface and bottom temperature data during the summer survey period. Appendices provide station data, summarized catch data by station, species listings, and detailed analyses of abundance and biological data of the sampled populations.