2020 Fiscal Year Final Research Report
High-sensitivity tracer assay for oxygen consumption rate in ocean and lakes using 17O as a tracer
Project/Area Number |
19K22908
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Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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Allocation Type | Multi-year Fund |
Review Section |
Medium-sized Section 63:Environmental analyses and evaluation and related fields
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Research Institution | Nagoya University |
Principal Investigator |
Tsunogai Urumu 名古屋大学, 環境学研究科, 教授 (50313367)
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Project Period (FY) |
2019-06-28 – 2021-03-31
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Keywords | 溶存酸素 / 呼吸速度 / 光合成速度 / 安定同位体 / トレーサー / 海洋 / 湖沼 / 伊勢湾 |
Outline of Final Research Achievements |
A new method to quantify the respiration rates in water columns by using the trace stable oxygen isotope (O-17) as a tracer is developed. In this method, the oxygen molecules of which oxygen atoms have been replaced by O-17 are added to water samples sealed in glass bottles. Because the added oxygen molecules were converted to water molecules in the bottles through respiration, the respiration rates can be estimated by measuring temporal variations in the triple oxygen isotopic compositions of water. By using the new method, vertical distributions of respiration rates were measured in the water columns of a costal ocean area and a mesotrophic lake where hypoxic water mass can be found at the bottom. We concluded that the water column respiration is as important as the respiration in the water-sediment interface during the formation of the hypoxia in each water column. The new method can be applicable to determine the respiration rates in the open ocean water columns as well.
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Free Research Field |
同位体地球化学
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Academic Significance and Societal Importance of the Research Achievements |
各水環境における水中の酸素消費速度 (=呼吸速度) の大きさや、その季節変動や長期変化の実態を把握すること、さらにその大小を規定する環境因子を明らかにすることは、人類にとってきわめて優先度の高い課題であるが、暗瓶法等の従来の呼吸速度定量法は検出感度が低く、また確度にも問題があった。本研究で開発した新手法は高感度、高確度かつ簡便に水中の呼吸速度定量を実現する画期的な手法であり、水中呼吸速度の観測を一般化・普遍化出来る。貧酸素水塊発生時期予測の高精度化が実現し、貧酸素水塊発生原因の解明も、容易になる。
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