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タイトル
  • en Density and sound-speed contrasts, and target strength of Japanese sandeel Ammodytes personatus
作成者
    • en Yasuma, Hiroki
    • en Nakagawa, Ryo
    • en Yamakawa, Takashi
    • en Aoki, Ichiro
アクセス権 open access
権利情報
  • ja © 2009 公益社団法人日本水産学会
  • en © 2009 The Japanese Society of Fisheries Science
  • en The final publication is available at www.springerlink.com
主題
  • Other en Ammodytes personatus
  • Other en Density contrast
  • Other en Japanese sandeel
  • Other en Sound-speed contrast
  • Other en Target strength
  • Other en Theoretical scattering model
  • NDC 468
内容注記
  • Abstract en Sound-speed and density contrasts (h and g, respectively), important acoustic material properties, of Japanese sandeel Ammodytes personatus were measured to estimate theoretical target strength (TS). The measured sound-speed contrast of adult fish varied between 1.016 and 1.023 (mean, 1.020), which showed temperature dependence. The measured density contrast differed significantly between juvenile and adult. The density contrast of juvenile varied between 1.017 and 1.024 (1.021), and that of adult varied between 1.026 and 1.038 (1.032). Using these results, TS at 38 and 120 kHz in the fishing season were estimated by an empirical sound scattering model. TS of an individual fish varied significantly with change of tilt angle. TS of near-dorsal aspect (TSmax) and tilt-averaged TS (TSave) differed up to 7 dB. At both frequencies, two different TSave-length relationships (TSave = a log L + b) were obtained for adult and juvenile. The coefficients of log L of adult were close to 20, suggesting that backscattering strength was proportional to the square of body length. These values were larger in juvenile (34.0 at 120 kHz, 56.5 at 38 kHz), suggesting that backscattering strength varied drastically with the cube or fifth power of body length.
出版者 en Springer Japan
日付
    Issued2009-05
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/2115/38598
関連
  • isVersionOf DOI https://doi.org/10.1007/s12562-009-0091-3
収録誌情報
    • PISSN 0919-9268
      • en Fisheries Science
      • 巻75 号3 開始ページ545 終了ページ552
ファイル
コンテンツ更新日時 2023-07-26