Understanding the Mechanisms of oligotrophication in Mutsu Bay for sustainable bivalve culture
| Project/Area Number |
18K05776
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 40030:Aquatic bioproduction science-related
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| Research Institution | Hokkaido University |
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Principal Investigator |
KUDO Isao 北海道大学, 水産科学研究院, 教授 (00195455)
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| Co-Investigator(Kenkyū-buntansha) |
芳村 毅 北海道大学, 水産科学研究院, 准教授 (20371536)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2020: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2018: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
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| Keywords | 栄養塩 / 基礎生産 / 海底耕耘 / ホタテガイ養殖 / 物質循環 / ホタテガイ / 貧栄養化 / 栄養塩循環 / 持続的ホタテガイ養殖 / 栄養塩回帰 / 栄養塩動態 |
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| Outline of Final Research Achievements |
Oligotrophication, a decreasing trend in nutrient concentration has been revealed in Mutsu Bay, where intensive scallop hanging culture is conducted. The objectives of this study are to elucidate the mechanisms of the oligotrophication threatening sustainable biological production in the coastal areas and to propose the effective policies for it. Nutrients were depleted in summer and primary productivity (scallop diet) was depressed by the nutrient deficiency. Bottom sediment cultivation was conducted to examine the enhancement of return of nutrients from the sediment. The amounts of this return were estimated as much as 10-20% of the standing stock in the water column. Thus, the bottom sediment cultivation is an effective option for preventing oligotrophication in this area.
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| Academic Significance and Societal Importance of the Research Achievements |
「貧栄養化」については、近年日本各地で認識されはじめた新しい現象であり、本研究で取り上げた青森県陸奥湾における「貧栄養化」は、ホタテガイ養殖によって水揚げ及びホタテガイ糞粒の堆積物への除去により栄養塩元素が減少した事が、その要因として考えられる。養殖漁業と栄養塩環境の関係を明らかにする点は、他の「貧栄養化」研究では着目されていない独自の着想である。また、その最終目標として栄養塩が乏しい貧栄養環境において持続的な生物生産活動を行うために、栄養塩を有効に循環させる方策としての海底耕耘の実用性を評価する点は、水産業を持続可能に維持していく将来モデルを創造する基礎となる。
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Report
(4 results)
Research Products
(3 results)
