| The 2003 to 2008 U.S. West Coast bottom trawl surveys of groundfish resources off Washington, Oregon, and California : estimates of distribution, abundance, length, and age composition - :4051 | National Marine Fisheries Service (NMFS)
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The 2003 to 2008 U.S. West Coast bottom trawl surveys of groundfish resources off Washington, Oregon, and California : estimates of distribution, abundance, length, and age composition
  • Published Date:
    2011
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The  2003 to 2008 U.S. West Coast bottom trawl surveys of groundfish resources off Washington, Oregon, and California : estimates of distribution, abundance, length, and age composition
Details:
  • Corporate Authors:
    Northwest Fisheries Science Center (U.S.)
  • Description:
    "The Northwest Fisheries Science Center's Fishery Resource Analysis and Monitoring Division conducts an annual West Coast Groundfish Bottom Trawl Survey (WCGBTS) from May to October each year. The WCGBTS is a continuation of a number of transect-based surveys conducted between 1977 and 2002. This report summarizes the results of the annual WCGBTSs from 2003 to 2008. WCGBTSs collects data on more than 90 species described in the Pacific Coast Groundfish Fishery Management Plan to fulfill the mandates included in the Magnuson-Stevens Fishery Conservation and Management Act. The surveys are designed to provide fisheries-independent indices of stock abundance, which support stock assessment models for commercially and recreationally harvested groundfish species. The surveys also monitor long-term trends in distribution and abundance of West Coast groundfish species. Since 2003 the surveys have adopted a stratified-random sampling design and included the continental shelf (depth 55-183 m) and the continental slope (depth 184-1,280 m). WCGBTSs have been conducted each year by chartered commercial fishing vessels from mid-May until late October. An Aberdeen-type net with a small mesh codend liner has been used to sample fish biomass. Tows were made within randomly selected cells in three depth zones (55-183 m, 184-549 m, and 550-1,280 m) and five International North Pacific Fisheries Commission statistical areas. In 2004 the survey was subsequently grouped into two geographic strata, north and south of Point Conception, California. From 2003 to 2008, 3,971 successful tows were completed along the U.S. Pacific Coast south of Cape Flattery (47°20'N), Washington, and north of the U.S.-Mexico border (32°40'N). During this time, 750,000 individual lengths and 136,000 age structures were collected from species of management concern. In this report, we document operations and results of the 2003-2008 groundfish surveys with intent to summarize the data available for the creation of indices of abundance for stock assessment purposes"-Executive summary, page xv.

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