Marine environments recorded in siliceous microfossil skeletons: species-level analysis of isotopic ratios and minor trace elements

2021 Fiscal Year Final Research Report

• Project/Area Number: 18H01329
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 17050:Biogeosciences-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Takuya Itaki 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 (30509724)
• Co-Investigator(Kenkyū-buntansha): 堀川 恵司 富山大学, 学術研究部理学系, 准教授 (40467858) ; 井尻 暁 国立研究開発法人海洋研究開発機構, 超先鋭研究開発部門(高知コア研究所), 主任研究員 (70374212) ; 岡崎 裕典 九州大学, 理学研究院, 准教授 (80426288)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 古海洋 / 指標 / 珪質微化石 / 放散虫 / 同位体比 / 人工知能

Outline of Final Research Achievements

Oxygen isotope ratio and trace elements recorded in siliceous microfossil skeletons such as diatoms and radiolarians are expected to be powerful tools for paleoenvironmental studies using sediments from areas or periods where carbonates are not preserved, however what kind of environmental information these values actually indicate is not fully understood. In this study, we developed a system that links the latest technology of automatic sorting and accumulation of fine particles with the automatic classification of microfossils using artificial intelligence, and established a method to accumulate a large amount of siliceous microfossils of a single species. This has paved the way for the analysis of small siliceous microfossils as a single species, which has been difficult in the past.

Free Research Field

古海洋学

Academic Significance and Societal Importance of the Research Achievements

手動では困難な小型の珪質微化石（放散虫）を自動で分類し大量に集積するシステムが構築されたことで、これまで実例のない、単種の放散虫の骨格に記録された同位体比・微量元素などの分析に道筋をつけた。これによって、古海洋研究に新たな指標の開発が可能となり、今後、多種多様な微化石に応用されることで、新規研究分野の創出にも繋がることが期待される。