Estimation of CO2 stress threshold of corals by real-time observation of photosynthesis and calcification

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K17885
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Tokyo Metropolitan University (2022); National Institute of Advanced Industrial Science and Technology (2021)
• Principal Investigator: Yamamoto Shoji 東京都立大学, 都市環境科学研究科, 特任教授 (90775751)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: 連続測定 / アルカリ度 / 石灰化 / サンゴ / 海洋酸性化 / 地球温暖化

Outline of Final Research Achievements

In this research, the total alkalinity measurement system devised by Yamamoto was employed to assess photosynthetic and calcification reactions within a coral, allowing for the examination of minute-scale responses. Notably, we achieved real-time monitoring of the photosynthetic response exhibited by symbiotic zooxanthellae and the calcification response of Acropora tenuis. Furthermore, the continuous observation of calcification in Acropora aspera, under varying light intensity conditions, revealed a noteworthy inhibition of calcification when exposed to intense light surpassing 1000 μmol/m2/s. By employing our experimental system, which integrates a continuous total alkalinity measurement device with a dissolved oxygen meter, we have successfully established a method for measuring coral calcification and zooxanthellae photosynthetic response on a minute scale.

Free Research Field

海洋化学

Academic Significance and Societal Importance of the Research Achievements

本研究では、サンゴの石灰化と共生している褐虫藻の光合成応答を分スケールで測定することに成功した。サンゴと褐虫藻の共生関係の理解がより一層深まる点で学術的な意義を持つ。また、地球規模の社会問題である温暖化や海洋酸性化に対して、高い生物多様性をもつサンゴ礁生態系およびサンゴが、具体的にどの程度まで健全でいられるかの指標を提供でき、実社会へも大きく貢献できると考える。