Biogeochemical linkage in the polar - subarctic region via sea ice melting water

2021 Fiscal Year Final Research Report

• Project/Area Number: 17H00775
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Hokkaido University
• Principal Investigator: Nishioka Jun 北海道大学, 低温科学研究所, 教授 (90371533)
• Co-Investigator(Kenkyū-buntansha): 黒田 寛 国立研究開発法人水産研究・教育機構, 水産資源研究所(札幌), 主任研究員 (30531107) ; 鈴木 光次 北海道大学, 地球環境科学研究院, 教授 (40283452)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 西部ベーリング海 / 北極海 / アナディル湾 / オホーツク海 / 鉄・栄養塩 / 海氷融解水 / 春季ブルーム

Outline of Final Research Achievements

We conducted field observations in the northwestern Bering Sea and the Sea of Okhotsk, which are subpolar marginal seas, and adjacent subarctic waters, and evaluated the effects of the inflow of melting water from the sea ice on the distribution of nutrient such as iron and nutrients, and the growth of phytoplankton species. The results suggest that the East Sakhalin Current within the Sea of Okhotsk and sea ice meltwater carry iron from continental shelf origin over a wide area of the southern Sea of Okhotsk and coastal Oyashio waters, and forming water masses characterized by high nutrient and iron concentrations, which have a significant impact on phytoplankton growth during the spring season. The results of observational studies of the western Bering Sea to East Sakhalin Current showed that the western Bering Sea is an important region that links the subarctic and polar regions through nutrient cycling.

Free Research Field

化学海洋学

Academic Significance and Societal Importance of the Research Achievements

これまで極域（亜極域）と北太平洋亜寒帯域の物質循環的な繋がりを詳しく研究した例はなく、本研究によって日本近海の生物生産を生み出す栄養物質循環像の詳細が明らかになった。ロシア領海内を含めた観測データも取得され、今後、北太平洋の物質循環をより詳しく理解するための情報も飛躍的に増強された。これらは、我が国の水産資源を生み出す仕組みの理解に繋がるだけでなく、海洋における大気中二酸化炭素の吸収メカニズムを理解することにも役立つ知見となる。