Correlation between δ^(18)O, Sr/Ca and Mg/Ca of coral Acropora and seawater temperature from coral culture experiments

作     者：XIAO YingKai LIU WeiGuo MA YunQi ZHANG YanLing HE MaoYong LUO ChongGuang LIAO QingQiang 

作者机构：Qinghai Institute of Salt LakesChinese Academy of Sciences State Key Laboratory of Loess and Quaternary GeologyInstitute of Earth Environment Chinese Academy of Sciences Beihai Aquarium 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2014年第57卷第5期

页      面：1048-1060页

核心收录：

学科分类：07[理学] 0708[理学-地球物理学] 0704[理学-天文学] 0713[理学-生态学] 

基　　金：supported by National Natural Science Foundation of China (Grant Nos. 40976074 and 41173019) State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS (Grant. No SKLLQG1126) 

主　　题：coral culture seawater temperature oxygen isotope microelement ratio 

摘      要：To be used as proxies of seawater surface temperature （SST）, the 61Soc values and Sr/Ca and Mg/Ca ratios of scleractinian coral skeletons must be verified by coral culture experiments in the laboratory. This paper describes a coral culture experiment that was conducted at several seawater temperatures T （21-28℃） using a tandem aquarium system and the new method for depositing coral skeletons grown under controlled conditions. The δ180c values and the St/Ca and Mg/Ca ratios of the cultured coral were measured. We concluded that the δ18Oc values and Sr/Ca and Mg/Ca ratios of the cultured coral are clearly corre- lated with T. The linear regression curve is δ18Oc（‰）=-0.1427×T（℃）-0.1495 （n=18, r=0.955, p〈0.0001）, and the slope of -0.1427‰/°d℃ is at the low end of the range of published values （-0.13-0.29‰/°d℃）. The Sr/Ca ratio decreases with increas- ing T, whereas the Mg/Ca ratio increases with increasing T, indicating a negative correlation between Sr/Ca and Mg/Ca. Their linear regression curves are Sr/Ca（mmol/mol）=-O.O4156×T＋lO.59 （n=15, r=-0.789, p〈0.005） and Mg/Ca （mmol/mol）= 0.04974×T＋2.339 （n=17, r=-0.457, p〈0.05）, respectively, which demonstrate that when Mg/Ca and Sr/Ca are increased by one unit, T increases by 5.19℃and decreases by 15.62℃, respectively. These variations are significantly lower than published values.