Submarine groundwater discharge drives biogeochemistry in two Hawaiian reefs
Submarine groundwater discharge drives biogeochemistry in two Hawaiian reefs
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海底地下水排放驱动夏威夷两个珊瑚礁的生物地球化学
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Joseph K. Fackrell
中科院分区：
文献类型：
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作者：
C. Richardson;H. Dulai;B. Popp;K. Ruttenberg;Joseph K. Fackrell
在沿海珊瑚礁研究中，地下水输入通常被忽视为环境变化的驱动因素。为了评估地下水排放对珊瑚礁生物地球化学的影响，我们研究了位于夏威夷奥胡岛南岸Maunalua湾的两个边缘珊瑚礁环境，这些环境接收了大量的海底地下水排放。我们用高分辨率24小时营养物、溶解无机碳（DIC）、总碱度（TA）和δ13C-DIC测量补充了盐度、水温、pH、溶解氧和222Rn的25 -和30 - d时间序列测量，以评估地下水诱导和生物驱动的沿海碳酸盐化学在盐度梯度中的变化。这两个地点的海底地下水排放具有较低的pHT(7.36 ~ 7.62)，相对于周围海水DIC （1734 ~ 3046 μM）和TA （1716 ~ 2958 μM）含量变化的特征。在我们的研究地点，地下水驱动的沿海碳酸盐系统参数变异性通常与生物驱动的碳酸盐系统参数变异性处于同一数量级。此外，我们的数据揭示了在地下水驱动的物理化学梯度中，珊瑚礁代谢从净溶解到净钙化的转变。在地下水暴露水平高的地点，净群落产量和钙化率降低。我们的研究结果揭示了在检查沿海碳酸盐化学时考虑地下水输入的重要性。
Groundwater inputs are typically overlooked as drivers of environmental change in coastal reef studies. To assess the impact of groundwater discharge on reef biogeochemistry, we examined two fringing reef environments, located in Maunalua Bay on the south shore of O‘ahu, Hawai‘i, that receive large inputs of submarine groundwater discharge. We supplemented 25‐ and 30‐d time series measurements of salinity, water temperature, pH, dissolved oxygen, and 222Rn with high‐resolution 24‐h nutrient, dissolved inorganic carbon (DIC), total alkalinity (TA), and δ13C–DIC measurements to evaluate both groundwater‐induced and biologically‐driven changes in coastal carbonate chemistry across salinity gradients. Submarine groundwater discharge at these two locations was characterized by low pHT (7.36–7.62), and variable DIC (1734–3046 μM) and TA (1716–2958 μM) content relative to ambient seawater. Groundwater‐driven variability in coastal carbonate system parameters was generally on the same order of magnitude as biologically‐driven variability in carbonate system parameters at our study locations. Further, our data revealed a shift in reef metabolism from net dissolution to net calcification across this groundwater‐driven physicochemical gradient. At sites with high levels of groundwater exposure, net community production and calcification rates were reduced. Our findings shed light on the importance of considering groundwater inputs when examining coastal carbonate chemistry.
海洋酸化加速了珊瑚礁的生物侵蚀。
影响因子：
3.7
作者：
Wisshak M;Schönberg CH;Form A;Freiwald A
通讯作者：
Freiwald A