Effect of ocean acidification on coral calcificationt

2016 Fiscal Year Final Research Report

• Project/Area Number: 26340051
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental impact assessment
• Research Institution: University of the Ryukyus
• Principal Investigator: OHDE Shigeru 琉球大学, 理学部, 教授 (20117568)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 海洋酸性化 / 二酸化炭素 / サンゴ / 石灰化 / アラゴナイト / pH / 沖縄

Outline of Final Research Achievements

Atmospheric carbon dioxide is predicted to be double of pre-industrial period in 2100. Such an increase reduces surface ocean pH and carbonate ion in seawater. We evaluated effects of seawater pH and carbonate on coral calcification. From the coral culture data obtained from the field and laboratory, the calcification is possibly controlled by an reaction law, R=k( Ω-1), where R is the rate, k is the rate constant, and Ω is the seawater saturation state with respect to aragonite. If atmospheric carbon dioxide increases from ~280 ppm in 1800 to ~400 ppm in 2017 and to ~560 ppm in 2100, seawater Ω is predicted to decrease from 4.5 to 3.8 and 3.0, respectively. Using the above model equation, the coral calcification rate is predicted to decline 80% and 57% by 2017 and 2100, respectively. In conclusion, coral calcification is closely coupled to seawater carbon dioxide and Ω, and declined coral calcification is predicted near future when atmospheric carbon dioxide further increases.

Free Research Field

海洋環境化学