2022 Fiscal Year Final Research Report

A study of the extinction of marine organisms at the end of the Cretaceous using corals and foraminifera breeding experiments

Research Project

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Project/Area Number	18K18793
Research Category	Grant-in-Aid for Challenging Research (Exploratory)
Allocation Type	Multi-year Fund
Review Section	Medium-sized Section 17:Earth and planetary science and related fields
Research Institution	National Institute of Advanced Industrial Science and Technology
Principal Investigator	Suzuki Atsushi 国立研究開発法人産業技術総合研究所, 地質調査総合センター, 研究グループ長 (60344199)
Co-Investigator(Kenkyū-buntansha)	黒柳あずみ東北大学, 学術資源研究公開センター, 准教授 (20536510) 井口亮国立研究開発法人産業技術総合研究所, 地質調査総合センター, 主任研究員 (50547502) 大野宗祐千葉工業大学, 惑星探査研究センター, 上席研究員 (80432631) 酒井一彦琉球大学, 熱帯生物圏研究センター, 教授 (50153838)
Project Period (FY)	2018-06-29 – 2023-03-31
Keywords	海洋酸性化 / 飼育実験 / 石灰化
Outline of Final Research Achievements	The impact of the extinction of marine organisms at the end of the Cretaceous was greater for coccolithophytes and smaller for diatoms, which is more in harmony with the "ocean acidification by sulfuric acid rain" theory than the "photosynthesis inhibition by impact winter" theory. First, we tested the addition of sulfuric acid to corals (early stage polyps of Acropora spp.) and foraminifera (reef dwelling benthic species), and found that the area of early stage coral polyps tended to decrease as the amount of sulfuric acid added increased. Next, we prepared highly alkaline seawater that mimicked the composition of seawater during the Cretaceous period and tested the growth of early coral polyps. The Cretaceous seawater showed a calcification rate similar to that of present-day seawater with similar carbonate saturation.
Free Research Field	生物地球化学
Academic Significance and Societal Importance of the Research Achievements	本研究課題による取り組みは、生物絶滅現象の新しい研究手段としての生物飼育実験法を提唱するものである。また、今回の予察的な結果は、海水の炭酸飽和度が石灰化に重要なパラメータであることを確認するとともに、将来の地球温暖化の緩和を目指して検討が進められている海洋ネガティブエミッション・海洋アルカリ増進技術の試みに関係した示唆にも富む。