Variation in Marine nitrogen budgets during the last 200-year global warming

2021 Fiscal Year Final Research Report

• Project/Area Number: 17H04708
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Environmental dynamic analysis
• Research Institution: Kyushu University (2018-2021); Hokkaido University (2017)
• Principal Investigator: Yamazaki Atsuko 九州大学, 理学研究院, 助教 (40723820)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 海洋窒素収支 / 地球温暖化 / サンゴ骨格 / 窒素同位体比

Outline of Final Research Achievements

The possibility that nitrogen, essential for marine life, is declining in response to global warming has been discussed. This study investigated changes in the ocean nitrogen budget associated with global warming using nitrogen isotope ratio measurements of reef-building coral skeletons. The results showed that the amount of nitrogen in the ocean surface layer tends to decrease with warming by comparing the world's largest nitrogen-fixing oceans, the Caribbean Sea in the North Atlantic, Hawaii in the Central Pacific, and Oman, which faces the Arabian Sea. In addition, the supply of deep to the surface water with decadal to multi-decadal oscillations in water temperature is suggested to be an essential source of nitrogen and phosphorus in tropical and subtropical regions.

Free Research Field

サンゴ礁地球環境学

Academic Significance and Societal Importance of the Research Achievements

近年、人為起源の二酸化炭素に起因する地球温暖化によって、海洋の窒素量が減少している可能性が議論されてきましたが、十分な証拠がありませんでした。窒素は生物にとって必要不可欠な元素であり、海洋表層の窒素の存在量の均衡は生態系に大きな影響を与えます。本研究はサンゴ礁海域において地球温暖化に伴う海洋表層の窒素の存在量の変化を示したものであり、温暖化が生態系に不可欠な元素の供給量を変化させることを示す重要なデータを提供しました。