1988 Fiscal Year Final Research Report Summary
Studies on inter-relationships between phytoplankton and zooplankton in patchy distributional manner
| Project/Area Number |
60440016
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
General fisheries
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| Research Institution | Tohoku University |
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Principal Investigator |
TANIGUCHI Akira Faculty of Agriculture,Tohoku University, 農学部, 教授 (30002091)
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| Co-Investigator(Kenkyū-buntansha) |
SASAKI Hiroshi Ditto, 農学部, 教務職員 (10183378)
FUJITA Naoji Ditto, 農学部, 助手 (10005639)
NAKAMURA Yasue Faculty of Agriculture,Tohoku University, 農学部, 助手 (10005613)
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| Project Period (FY) |
1985 – 1988
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| Keywords | epibenthic plankton / feeding activity of copepods / mixotroph / plankton patch / planktonic ciliates / 混合栄養者 |
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| Research Abstract |
The main aims of this project are to figure out the patchy distributions of phytoplankton and zooplankton in nature and then determine the inter-relationships between phytoplankton and zooplankton at different population densities, which may occur in nature depending on the presence or absence of patches. The data obtained can be summarized as below.
(1) Many instances of patchy distribution in fine scale of both phyto- and zooplankton in various sea areas were recorded by continuous towings of a Longhurst-Hardy Plankton Recorder and a Scatter-Fluorescence-Temperature-Depth Recorder.
(2) Diel rhythms in feeding activity of herbivorous copepods were found in natural populations Magnitudes of the rhythm changing with different feeding/starving regimes was also examined. Then ecological significance of diel vertical migration of copepods, which makes copepods encounter periodically phytoplankton patches in the surface layer, could be speculated.
(3) Distributional patterns of phytoplankton and heterotrophic and mixotrophic planktonic ciliates in Onagawa Bay were illustrated. Despite very weak swimming ability of the ciliates, each species seems to keep its specific position in water column which might be controlled by the degree of dependence on phtoplankton as a energy source.
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