著者

杉松 宏一 八木 宏 小口 哲史 川俣 茂 宇田川 徹 中山 哲嚴 島村 信也 池川 正人 鈴木 彰

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.70, no.2, pp.I_411-I_415, 2014 (Released:2014-11-12)

参考文献数

6

被引用文献数

1

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To understand the characteristics of the current field and its seasonal variability off the Joban coast along the east coast of Japan, the continuous survey using the mooring system are performed from October 2012. The observed current was dominated by the along shore current with several days period caused by the continental shelf waves subjected to the meteorological disturbance with the seasonal variability. In addition, the cross shore current develops in summer because of the semi-diurnal internal tides caused by the strengthened density stratification. Furthermore, it is revealed that the southward mean current also has the seasonal variability by the geostrophic current with the enhanced baroclinic density fields except for the period when the warm water driven from the Kuroshio disturbance locates off the Joban coast.

著者

川俣 茂 長谷川 雅俊

出版者

日本水産工学会

雑誌

日本水産工学会誌 (ISSN:09167617)

巻号頁・発行日

vol.43, no.1, pp.69-79, 2006-07-15 (Released:2017-09-01)

参考文献数

37

被引用文献数

5

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Laboratory experiments were conducted to evaluate the effects of wave-induced oscillatory flow and temperature on feeding by the rabbitfish Siganus fuscescens on the kelp Ecklonia cava or Eisenia bicyclis. With a constant temperature of 20℃, feeding rates were very low from July to August and then increased until November. When feeding activity was highest, oscillating flow reduced feeding to 50% at the velocity amplitude of l.lm/s and to nil at ca 1.5m/s. An experiment with variable temperatures showed that temperature threshold for initiating feeding on kelp were variable with time, from 23℃ in late July to 17℃ in early November. Once reached maximal, feeding rate remained high until temperature was lower than 19℃ and then decreases to zero at 16℃. Contrary to expectations, the experimental results and wave-induced water velocity predictions lead to the conclusion that destructive feeding by S. fuscescens on kelp is very unlikely to be inhibited by waves on the Pacific coast of central Honshu, requiring further studies of the feeding ecology of S. fuscescens.

著者

川俣 茂 田井野 清也 宮地 麻央 中村 洋平

出版者

公益社団法人 日本水産学会

雑誌

日本水産学会誌 (ISSN:00215392)

巻号頁・発行日

vol.82, no.3, pp.306-314, 2016

被引用文献数

3

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イセエビ(頭胸甲長 CL:59-93 mm)によるツマジロナガウニ(4 サイズ群:殻径 10-19,20-29,30-39,40-49 mm)の捕食を水槽実験で調べた。被食ウニの最大殻径は CL の増加に伴い増加した。サイズ群別のウニに対する捕食成功率(捕食個数/攻撃回数)は,CL に対して最小サイズ群でほぼ一様に高く(約 75%),最大サイズ群で低く(<11%),また中間の 2 サイズ群で CL の増加に伴い増加した。この結果は,大型(>40 mm)のウニでは大型イセエビでも捕食され難くなることを示唆する。