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【博士後期課程 合同セミナー(H30-B-015)】のお知らせ          

Last Update : 2018-11-05 13:32

合同セミナー【H30-B-015】

Advanced Seminar of Specialization 【H30-B-015】

「Depth retention and aggregation of zooplankton and the utilization of prey patches by fish」

博士後期課程在学生 各位

To Doctoral Course Students

博士後期課程の合同セミナーのお知らせです。合同セミナー番号は次のとおりです。

Information of an Advanced Seminar of Specialization of doctoral course students, a seminar number is as follows,

合同セミナー番号【H30-B-015】

なお、品川地区は、学務部教務課大学院係(講義棟1階)のカウンター、越中島地区は、1号館事務室の掲示板前、の合同セミナーのバインダーに、それぞれ綴っております。

There is a file of the Advanced Seminar of Specialization as follows,

Shinagawa Campus: Graduate School Section

Etchujima Campus: Front of the bulletin board of the Administration Division

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「Depth retention and aggregation of zooplankton and the utilization of prey patches by fish」
 

日時:2018年11月8日(木) 10:30-12:00

Date&Time: November 8, 2018, 10:30~12:00

場所:品川キャンパス  2号館 208教室

Venue:208Lecture Room,2Bulding, Shinagawa Campus

使用言語:英語

Language:English

講演者:Speaker

Prof. Amatzia Genin

The H. Steinitz Marine Biology Laboratory of the Hebrew University

概要:Abstract

Many planktivorous fish in coral reefs are site-attached, foraging upstream of their shelters on prey swept with the currents. Predation by these fishes is remarkably intense and efficient. A single group of fish can remove more than half of the zooplankton passing through their foraging space. Consequently, the abundance of zooplankton in water parcels flowing over the reef declines at a rate of about 50% per hour, leading to an order of magnitude lower zooplankton abundance and a shift to a smaller body size near the reef, compared with the open waters, just 200-300 away. Cross-shore currents, largely driven by differential heating and cooling of the water over a sloping bottom, replenish the depleted waters near the reef with plankton-rich waters originating off shore. Predation rates by individual fish increase linearly with increasing prey density with no apparent "leveling-off", not even at exceedingly high prey densities. This unique functional response results from the fish's selective predation on micro-aggregates, so that the number of prey captured per strike increases with prey density. Aggregations of zooplankton are expected near the coast due to the behavioral response of zooplankton to vertical flows, driven by the cross-shore currents. Such aggregations are formed when zooplankters swim against vertical flows in order to retain their depth. The depth retention, proposed long ago, is documented here for the first time in situ, based on some 200,000 tracks of individual zooplankters (mostly copepods), obtained with a high-frequency (1.6 MHz) multi-beam sonar (FishTV). The "supply" and aggregation of prey under conditions of vertical currents and the remarkable "sink" due to fish predation are key processes in the benthic-pelagic coupling in coral reefs and possibly in other coastal and oceanic habitats. Implications to trophic subsidy of coastal ecosystems and micro-patchiness of zooplankton will be discussed.

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担当教員:山崎 秀勝(海洋環境学部門 教授)

問い合せ:hide@kaiyodai.ac.jp

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