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The 2019 eastern and northern Bering Sea continental shelf trawl surveys : results for commercial crab species
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2020
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Description:The eastern Bering Sea bottom trawl survey has been annually conducted since 1975 by the Resource Assessment and Conservation Engineering Division of the Alaska Fisheries Science Center, National Marine Fisheries Service. The purpose of this survey is to collect data on the distribution and abundance of crab, groundfish, and other benthic resources in the eastern Bering Sea. These data are used to estimate population abundance and biomass for the management of commercially important species. This document includes the time series of results from 1975 to the present. In 2019, 375 total stations were sampled on the eastern Bering Sea shelf from 3 June to 28 July.
In 2019 the overall estimated biomass and abundance of Bristol Bay red king crab (Paralithodes camtschaticus) remained approximately the same, although there was a decline in legal male crab. Mature and legal red king crab males in the Pribilof Islands increased, while females and immature males declined or remained steady. Both red king crab populations saw an increase in pre-recruit abundance. There was an overall increase in estimated blue king crab biomass and abundance, except for Pribilof Islands immature females, of which none were caught in the survey. Estimated biomass and abundance of Tanner crab (Chionoecetes bairdi) declined for legal and mature males. Females and immature males remained approximately the same, except for the biomass of immature males east of 166o W, which increased. There was an overall increase in legal, mature, and pre-recruit male snow crab (Chionoecetes opilio), while immature males and all females declined.
In addition to the standard eastern Bering Sea survey, in 2019, following the conclusion of the standard survey, 144 stations were sampled in the northern Bering Sea region, encompassing the region south of Bering Strait, and including Norton Sound. These stations were sampled between 28 July and 20 August. We report the results of this survey separately from the eastern Bering Sea survey, within the northern Bering Sea section of this report. Blue king crab occurred largely in the region north of St. Lawrence Island. Estimated biomass and abundance declined in 2019 and densities were lower than for the St. Matthew Island stock. Red king crab occurred primarily in Norton Sound, with an overall decline in the biomass and abundance of mature males and an increase in immature crab. Density and abundance estimates for immature red king crab in Norton Sound were higher than observed in the Bristol Bay District, but the reverse pattern was seen for mature red king crab. Snow crab dominated the northern Bering Sea catch, with increases in both biomass and abundance estimates for mature and legal crab, especially along the border between the eastern Bering Sea and northern Bering Sea survey areas. Immature snow crab were distributed throughout most of the northern Bering Sea, but declined in overall biomass and abundance.
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Rights Information:Public Domain
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Compliance:Submitted
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