Effect of herbicides on competition between marine diatoms and flagellates: A comprehensive search of herbicides causing trigger the flagellates blooms.
| Project/Area Number |
16K18738
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Aquatic bioproduction science
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| Research Institution | Fisheries Research and Education Agency |
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Principal Investigator |
Onduka Toshimitsu 国立研究開発法人水産研究・教育機構, 瀬戸内海区水産研究所, 主任研究員 (00371972)
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| Co-Investigator(Renkei-kenkyūsha) |
NAKAYAMA NATSUKO 国立研究開発法人水産研究・教育機構, 瀬戸内海区水産研究所, 主任研究員 (20612675)
ITO KATSUTOSHI 国立研究開発法人水産研究・教育機構, 瀬戸内海区水産研究所, 主任研究員 (80450782)
MOCHIDA KAZUHIKO 国立研究開発法人水産研究・教育機構, 瀬戸内海区水産研究所, 環境保全センター長 (00371964)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | 珪藻 / 鞭毛藻 / プランクトン遷移 / 福山港 / 藻類競合関係 / 除草剤 / 感受性差異 |
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| Outline of Final Research Achievements |
The acute toxicities of eleven herbicides having different action mechanisms to a diatom Chaetoceros sp. and a flagellate Heterosigma akashiwo were assessed, Chaetoceros sp. was more sensitive to inhibitors of photosystem II in photosynthesis such as bromacil than H. akashiwo. In addition, ten kind of herbicides were identified in environmental water in Hukuyama Port where flagellate blooms were generated in recent years, concentration of the herbicides in environmental water over 50 times lower than the acute toxicity values. Moreover, diversity of marine microalgae in surface water in Fukuyama Port was calculated, and relationships between the diversity and environmental parameters were investigated, there was a significant correlation between bromacil concentration and the community structure of marine microalgae. Herbicides may therefore influence the community structure of marine microalgae including generation of flagellate blooms in the environment.
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| Academic Significance and Societal Importance of the Research Achievements |
日本近海では鞭毛藻による有害赤潮が頻発しており、甚大な漁業被害がもたらされている。本研究では、鞭毛藻が優占する機構について除草剤の影響の観点から検討し、毒性試験を実施するような藻類の増殖に適した条件下では少なくとも単独の薬剤では影響が認められないものの、実環境中では除草剤が微細藻類群集の変化に影響を及ぼす可能性を示した。また、作用機序の異なる除草剤の中で光合成の光化学系Ⅱ阻害剤がより低濃度で藻類に影響を及ぼし、実環境中の微細藻類群集の変化とも相関が認められた。そのため、これらの除草剤の使用の制限や、他の作用機序の除草剤への置き換えにより、赤潮による漁業被害の軽減が可能になると期待される。
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Report
(4 results)
Research Products
(3 results)
