Measurements of density contrast and sound-speed contrast for target strength estimation of Neocalanus copepods (Neocalanus cristatus and Neocalanus plumchrus) in the North Pacific Ocean

Matsukura Ryuichi; 松倉 隆一; Yasuma Hiroki; 安間 洋樹; Murase Hiroto; 村瀬 弘人; Yonezaki Shiroh; 米崎 史朗; Funamoto Tetsuichiro; 船本 鉄一郎; Honda Satoshi; 本田 聡; Miyashita Kazushi; 宮下 和士

タイトル	en Measurements of density contrast and sound-speed contrast for target strength estimation of Neocalanus copepods (Neocalanus cristatus and Neocalanus plumchrus) in the North Pacific Ocean ja 北太平洋におけるNeocalanus属カイアシ類（N. cristatusおよびN. plumchrus）の理論ターゲットストレングス推定に必要な密度比, 音速比の測定
作成者	en Matsukura, Ryuichi ja 松倉, 隆一 en Yasuma, Hiroki ja 安間, 洋樹 en Murase, Hiroto ja 村瀬, 弘人 en Yonezaki, Shiroh ja 米崎, 史朗 en Funamoto, Tetsuichiro ja 船本, 鉄一郎 en Honda, Satoshi ja 本田, 聡 en Miyashita, Kazushi ja 宮下, 和士 NRID 1000070301877
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 Copepod Other en Density contrast Other en Neocalanus cristatus Other en Neocalanus plumchrus Other en Signal-to-noise ratio Other en Sound-speed contrast Other en Target strength NDC 663
内容注記	Abstract en The mass density and sound-speed contrasts against surrounding seawater (g and h, respectively) of Neocalanus copepods (N. cristatus and N. plumchrus) were measured in 2006 and 2007 to compute the theoretical target strength (TS). The values of g ranged from 0.997 - 1.009 in N. cristatus and from 0.995 - 1.009 in N. plumchrus. There were no correlations in prosome length (PL) and g. The values of h ranged from 1.006 - 1.021 in N. cristatus and 1.013 - 1.025 in N. plumchrus and varied by changes in temperature. TS were estimated by theoretical sound scattering model with the values of g and h that computed by temperature, salinity, and depth where the specimens were collected. Regressions of the tilt averaged TS vs. PL were obtained at 38, 120, and 200 kHz. The averaged TS of N. cristatus and N. plumchrus at 120 kHz, which is widely used as a high frequency, were ranged from -110.0 to -103.1 dB and from -121.4 to -109.7 dB. The higher the frequency was, the higher the value of averaged TS. The differences of TS at 120 and 38 kHz varied from 14.8 to 16.4 dB in N. cristatus, from 17.9 to 18.7 dB in N. plumchrus. The differences of TS at 200 and 120 kHz varied from 2.9 to 5.5 dB in N. cristatus, from 5.3 to 6.5 dB in N. plumchrus. Abstract ja Neocalanus属カイアシ類の理論ターゲットストレングス（TS）を推定するため，海水との密度比g, 音速比hを測定した。N. cristatusとN. plumchrusのgの範囲は0.997～1.009, 0.995～1.009で体長との相関はみられなかった。一方hは1.006～1.021, 1.013～1.025の範囲で水温による変化がみられた。採集深度における水温, 塩分, 深度から計算したg, hを用い, DWBAモデルにより周波数38, 120, 200kHzにおける理論TSと体長の回帰式を得た。
出版者	en Springer Japan
日付	Issued2009-11
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/2115/40066
関連	isVersionOf DOI https://doi.org/10.1007/s12562-009-0172-3
収録誌情報	PISSN 0919-9268 en Fisheries Science 巻75 号6 開始ページ1377 終了ページ1387
ファイル	fulltext FS75-6_1377-1387.pdf 471.64 KB (application/pdf) Issued2009-11
コンテンツ更新日時	2023-07-26