2001 Fiscal Year Final Research Report Summary
Evaluation of shellfish culture potential in coastal areas based on carrying capacity of waters
| Project/Area Number |
11660181
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General fisheries
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
FURUYA Ken Graduate School of Agricultural and Life Sciences, THE UNIVERSITY OF TOKYO, Professor, 大学院・農学生命科学研究科, 教授 (30143548)
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| Co-Investigator(Kenkyū-buntansha) |
KOMATSU Teruhisa Ocean Research Institute, THE UNIVERSITY OF TOKYO, Associate Professor, 海洋研究所, 助教授 (60215390)
OTOBE Hirotaka Ocean Research Institute, THE UNIVERSITY OF TOKYO, Research Associate, 海洋研究所, 助手 (10169328)
KISHI Michio Hokkaido University, Graduate School of Fisheries Sciences, Professor, 大学院・水産科学研究科, 教授 (90214767)
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| Project Period (FY) |
1999 – 2001
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| Keywords | carrying capacity / rias on Sanriku coast / shellfish culture / dissolved oxygen / sediment trap / PAM / primary productivity / plant pigment |
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| Research Abstract |
Evaluation of carrying capacity of coastal waters was investigated for sustainable exploitation of biological production from coastal aquaculture. Field experiments were conducted in Otsuchi Bay, a ria in Sanriku coast on the northeastern coast of Japan. Accurate estimation of phytoplankton primary production and understanding of oxygen dynamics are of prime importance for scaling the carrying capacity. Bio-optical sensors for natural and active fluorescence prove to be useful approaches for rapid and accurate quantification of primary production. This was exemplified by field application of both the natural fluorescence technique and the pulse amplitude modulation of fluorescence to monitor primary production in aquaculture ground. Growth of the cultured kelp called wakame and phytoplankton was compared as competitors for nutrients during spring. As another important factor determining the carrying capacity, oxygen supply of subsurface layers is considered. During summer time, oxygen consumption of bottom sediment under shellfish rafts was high enough to exhaust dissolved oxygen within three to five days. However, no anoxic water was formed. Wind-driven circulation and inflow of subsurface coastal waters induced by the internal tide supplied enough dissolved oxygen to prevent the formation of anoxic layer.
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