Effects of seawater pH on growth and skeletal U/Ca ratios of Acropora digitifera coral polyps
Effects of seawater pH on growth and skeletal U/Ca ratios of Acropora digitifera coral polyps
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DOI：
10.1029/2011gl047786
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发表时间：
2011-06
影响因子：
5.2
通讯作者：
M. Inoue;R. Suwa;A. Suzuki;K. Sakai;H. Kawahata
中科院分区：
文献类型：
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作者：
M. Inoue;R. Suwa;A. Suzuki;K. Sakai;H. Kawahata
大气中二氧化碳含量增加引起的海洋酸化对海洋钙化的影响已经被研究过了，包括纹状珊瑚。然而，二氧化碳浓度升高对珊瑚早期发育生命周期阶段的影响研究很少。在本研究中，我们在PHT分别为6.55、7.31、7.64、7.77和8.03的海水中，通过CO2鼓泡控制，养殖了指纹藻的息肉。在40d的实验后，我们测量了息肉骨骼的干重，以探讨海水文石饱和状态与息肉生长的关系。此外，我们还测量了骨骼U/Ca比值，以评估其对pH的依赖性。珊瑚虫的骨骼重量随着文石饱和状态的增加而增加，并在pH 7.77以上达到一个明显的饱和平台。U/Ca比值与pH值呈强负相关，与骨骼生长速率(息肉重量)关系不大，提示骨骼U/Ca值可用于古pH的重建。
The impact of ocean acidification caused by the increasing atmospheric CO2 has been studied in marine calcifiers, including hermatypic corals. However, the effect of elevated pCO2 on the early developmental life‐cycle stage of corals has been little studied. In this study, we reared polyps of Acropora digitifera in seawater at pHT 6.55, 7.31, 7.64, 7.77, and 8.03, controlled by CO2 bubbling. We measured the dry weights of polyp skeletons after the 40‐d experiment to investigate the relationship between the seawater aragonite saturation state and polyp growth. In addition, we measured skeletal U/Ca ratio to estimate their pH dependence. Skeletal weights of coral polyps increased with the aragonite saturation state and reached an apparent saturation plateau above pH 7.77. U/Ca ratios had a strong inverse relationship with pH and a negligible relationship with skeletal growth rate (polyp weight), suggesting that skeletal U/Ca could be useful for reconstructing paleo‐pH.