Coral skeletal Sr/Ca has valuable potential as a proxy of sea surface temperatures (SSTs). However seawater pCO₂ can influence skeletal Sr incorporation and Sr/Ca-SST calibrations derived from present day corals may not be applicable to ancient specimens or older sections of modern corals deposited under lower seawater pCO₂ than the present day. In this study we analysed skeletal Sr/Ca in multiple genotypes of massive Porites spp. cultured over a range of seawater pCO₂ (from 180 to 750 μatm) and temperature (25 °C and 28 °C). Multiple linear regression analysis indicates that the Sr/Ca aragonite partition coefficient, K_D Sr/Ca is inversely related to seawater temperature and positively related to seawater pCO₂ (equivalent to changes in skeletal Sr/Ca of 0.046 mmol mol⁻¹ °C⁻¹ and 0.0002 mmol mol⁻¹ µatm⁻¹ respectively). Applying present day Sr/Ca-SST equations to older coral skeletons growing at lower pCO₂ could underestimate seawater temperatures. However K_D Sr/Ca vary significantly between some coral genotypes cultured at the same seawater pCO₂ indicating that other unidentified processes also influence skeletal Sr/Ca and it is unknown how these processes varied when ancient corals were deposited. We do not observe a significant relationship between K_D Sr/Ca and coral calcification rate after combining all coral genotypes to allow identification of the correct K_D Sr/Ca to apply to coral records.

珊瑚骨骼 Sr/Ca 具有作为海面温度 (SST) 代理的宝贵潜力。然而，海水 pCO ₂会影响骨骼 Sr 的掺入，并且源自当今珊瑚的 Sr/Ca-SST 校准可能不适用于沉积在比现在更低的海水 pCO ₂下的古代标本或现代珊瑚的较旧部分。在这项研究中，我们分析了大量Porites spp 的多个基因型中的骨骼 Sr/Ca 。在一定范围的海水 pCO ₂（从 180 到 750 μatm）和温度（25 °C 和 28 °C）下培养。多元线性回归分析表明 Sr/Ca 文石分配系数 K _DSr/Ca 与海水温度呈负相关，与海水 pCO ₂呈正相关（相当于骨骼 Sr/Ca 的变化分别为 0.046 mmol mol ^-1 °C ^-1和 0.0002 mmol mol ^-1  µatm ^-1）。将当今的 Sr/Ca-SST 方程应用于在较低 pCO ₂下生长的旧珊瑚骨骼可能会低估海水温度。然而，在相同海水 pCO _{2 下}培养的一些珊瑚基因型之间K _D Sr/Ca 差异显着表明其他未识别的过程也会影响骨骼 Sr/Ca 并且不知道这些过程在古代珊瑚沉积时如何变化。在结合所有珊瑚基因型以识别正确的 K _D Sr/Ca 以应用于珊瑚记录后，我们没有观察到 K _D Sr/Ca 与珊瑚钙化率之间的显着关系。