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タイトル
  • en The influence of warp length on trawl dimension and catch of walleye pollock Theragra chalcogramma in a bottom trawl survey
  • ja スケトウダラ着底トロール調査におけるワープ長の違いが網形状と漁獲に与える影響
作成者
    • en Chiba, Kenji
    • en Oshima, Tatsuki
    • en Honda, Satoshi
アクセス権 open access
権利情報
  • ja © 2005 公益社団法人日本水産学会
  • en © 2005 The Japanese Society of Fisheries Science
主題
  • Other en footgear contact
  • Other en trawl dimension
  • Other en trawl survey
  • Other en walleye pollock
  • Other en warp length
  • NDC 664
内容注記
  • Abstract en We examined variation in trawl dimension, bottom contact, and catch with differing warp lengths during walleye pollock surveys conducted by the Fisheries Research Agency. The ratio of warp length to fishing depth (scope ratio) was set at 2.5, 3.0 and 3.5 at depths of 110 m. At a 2.5 scope ratio, the net mouth shape and footgear contact fluctuated, as the trawl door did not contact the bottom. Footgear contact was complete when the scope ratio was 3.0 or more. Walleye pollock, sculpins, and flatfishes were the main catch in all tows, and the catch increased with scope ratio. There was no difference in the length frequency of n= 300 walleye pollock captured at 2.5 and 3.0 scope ratio. However, the length frequency at 3.5 was significantly different from that of other scope ratios. These results suggest the following: at a scope ratio of 3.0 or more, the trawl door will not leave the bottom at any depths. To compliment echo surveys for walleye pollock, a 3.0 scope ratio would be optimal, since the catch data for a 3.5 scope ratio was dissimilar from that of scope ratios.
出版者 en Blackwell Publishing
日付
    Issued2005-08
言語
  • eng
資源タイプ journal article
出版タイプ AM
資源識別子 HDL http://hdl.handle.net/2115/623
関連
  • isVersionOf DOI https://doi.org/10.1111/j.1444-2906.2005.01023.x
収録誌情報
    • PISSN 09199268
      • en Fisheries Science
      • 71 4 開始ページ738 終了ページ747
ファイル
    • fulltext Tables.pdf
    • 9.0 KB (application/pdf)
      • Issued2005-08
    • fulltext figure.pdf
    • 355.77 KB (application/pdf)
      • Issued2005-08
    • fulltext trawl.zip
    • 401.86 KB (application/zip)
      • Issued2005-08
コンテンツ更新日時 2023-07-26