Integrative understanding of marine nitrogen fixation based on global observations from tropics to polar regions.

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H04263
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: The University of Tokyo
• Principal Investigator: Shiozaki Takuhei 東京大学, 大気海洋研究所, 准教授 (90569849)
• Co-Investigator(Kenkyū-buntansha): 浜崎 恒二 東京大学, 大気海洋研究所, 教授 (80277871) ; 遠藤 寿 京都大学, 化学研究所, 助教 (80795055)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 窒素固定 / 極域

Outline of Final Research Achievements

Nitrogen fixation is the primary source of reactive nitrogen in the ocean. We found substantial nitrogen fixation near the Antarctic coast, especially around ice-covered regions. Nitrogen fixation has also been observed in the Arctic Ocean, indicating that marine nitrogen fixation is not a local process in the tropical and subtropical oligotrophic region, but is a ubiquitous process in the global ocean. We also revealed for the first time the genomes of nitrogen fixer in the Arctic Ocean. The polar environment shows heterogeneity compared to tropical and subtropical oligotrophic region. The genome information suggests that Arctic nitrogen fixers have some specialized functions adapting to their environment.

Free Research Field

微生物海洋学

Academic Significance and Societal Importance of the Research Achievements

海洋窒素固定は熱帯・亜熱帯海域貧栄養海域におけるローカルなプロセスであると考えられてきた。本研究によって極域を含む全球的なプロセスであることが明らかになったことはこれまでのパラダイムからの大きな変換をもたらす。窒素固定は海洋における主要な窒素源であり、基礎生産を制御している。極域を含めて海洋窒素固定を正確に見積もることは海洋基礎生産全体の理解に必要不可欠となる。