Permeable coral reef sediment dissolution driven by elevated pCO2 and pore water advection
Permeable coral reef sediment dissolution driven by elevated pCO2 and pore water advection
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DOI：
10.1002/grl.50948
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发表时间：
2013-09-28
影响因子：
5.2
通讯作者：
Eyre, B. D.
中科院分区：
文献类型：
--
作者：
Cyronak, T.;Santos, I. R.;Eyre, B. D.
海洋酸化（OA）预计将在下个世纪推动珊瑚礁生态系统从净碳酸钙（CaCO3）沉淀向净溶解的转变。虽然可渗透沉积物是珊瑚礁中最大的 CaCO3 储库，但在自然条件下尚未测量到未来 pCO(2) 水平下浅层 CaCO3 砂的溶解情况。在原位，在升高的 pCO(2)（类似于 800 mu atm）下的平流室孵育使沉积物从净沉淀转变为净溶解。与扩散条件（0.42 g CaCO3 m(-2) d(-1)）相比，孔隙水平流溶解速率（1.10 g CaCO3 m(-2) d(-1)）增加了一倍多。沉积物溶解可能会在下个世纪内使苍鹭岛泻湖的净生态系统钙化率降低8%，相当于全球珊瑚礁湖平均钙化率降低25%。需要考虑 CaCO3 沉积物的溶解，以便解决在未来预测的 CO2 增加情况下 OA 将如何影响珊瑚礁的净增长。
Ocean acidification (OA) is expected to drive the transition of coral reef ecosystems from net calcium carbonate (CaCO3) precipitating to net dissolving within the next century. Although permeable sediments represent the largest reservoir of CaCO3 in coral reefs, the dissolution of shallow CaCO3 sands under future pCO(2) levels has not been measured under natural conditions. In situ, advective chamber incubations under elevated pCO(2) (similar to 800 mu atm) shifted the sediments from net precipitating to net dissolving. Pore water advection more than doubled dissolution rates (1.10 g CaCO3 m(-2) d(-1)) when compared to diffusive conditions (0.42 g CaCO3 m(-2) d(-1)). Sediment dissolution could reduce net ecosystem calcification rates of the Heron Island lagoon by 8% within the next century, which is equivalent to a 25% reduction in the global average calcification rate of coral lagoons. The dissolution of CaCO3 sediments needs to be taken into account in order to address how OA will impact the net accretion of coral reefs under future predicted increases in CO2.