Stress-tolerant corals of Florida Bay are vulnerable to ocean acidification
Stress-tolerant corals of Florida Bay are vulnerable to ocean acidification
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佛罗里达湾的耐压珊瑚很容易受到海洋酸化的影响
DOI：
10.1007/s00338-013-1015-3
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发表时间：
2013
期刊：
影响因子：
3.5
通讯作者：
Langdon, C.
中科院分区：
文献类型：
--
作者：
Okazaki, R. R.;Swart, P. K.;Langdon, C.
现场钙化测量测试了一种假设，即来自pCO2和pH自然波动较大的环境(美国佛罗里达州海湾)的珊瑚将比实验室实验中变化较小的碳酸盐化学物质的珊瑚对海洋酸化的耐受性或敏感性较低。佛罗里达州海湾的二氧化碳浓度在夏季和冬季之间变化了几百ppm，与本世纪末预测的增幅大致相当。在普遍的环境化学条件下，以及在经过修正以模拟两年期间每两个月一次的pH下降0.1-0.2单位的条件下，测量了两个耐受胁迫的珊瑚物种--放射状珊瑚和光泽珊瑚的净光合作用和钙化速率。净光合作用不受pCO2升高和pH下降的影响，但饱和状态下单位降钙量分别下降52%和50%。这些结果表明，骨钙化的速度是最快的.放射线S。与之前研究过的珊瑚物种一样，鬣狗对饱和状态的降低也同样敏感。换句话说，对温度和盐度极端的胁迫耐受性以及经常暴露在pCO2和pH的大幅波动中，并不会使它们对海洋酸化的敏感度降低。这两个物种可能在佛罗里达州海湾存活下来，部分原因是它们在钙化过程中投入的能量比大多数其他物种要少，而且由于海草初级生产量高，平均饱和状态相对于附近近海水域的水平较高。
In situ calcification measurements tested the hypothesis that corals from environments (Florida Bay, USA) that naturally experience large swings in pCO2and pH will be tolerant or less sensitive to ocean acidification than species from laboratory experiments with less variable carbonate chemistry. The pCO2in Florida Bay varies from summer to winter by several hundred ppm roughly comparable to the increase predicted by the end of the century. Rates of net photosynthesis and calcification of two stress-tolerant coral species,Siderastrea radiansandSolenastrea hyades, were measured under the prevailing ambient chemical conditions and under conditions amended to simulate a pH drop of 0.1–0.2 units at bimonthly intervals over a 2-yr period. Net photosynthesis was not changed by the elevation in pCO2and drop in pH; however, calcification declined by 52 and 50 % per unit decrease in saturation state, respectively. These results indicate that the calcification rates ofS. radiansandS. hyadesare just as sensitive to a reduction in saturation state as coral species that have been previously studied. In other words, stress tolerance to temperature and salinity extremes as well as regular exposure to large swings in pCO2and pH did not make them any less sensitive to ocean acidification. These two species likely survive in Florida Bay in part because they devote proportionately less energy to calcification than most other species and the average saturation state is elevated relative to that of nearby offshore water due to high rates of primary production by seagrasses.