Oxygen metabolism and pH in coastal ecosystems: Eddy Covariance Hydrogen ion and Oxygen Exchange System (ECHOES)
Oxygen metabolism and pH in coastal ecosystems: Eddy Covariance Hydrogen ion and Oxygen Exchange System (ECHOES)
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沿海生态系统中的氧代谢和 pH 值：涡流协方差氢离子和氧交换系统 (ECHOES)
DOI：
10.1002/lom3.10038
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
D. McCorkle
中科院分区：
文献类型：
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作者：
M. Long;M. Charette;W. Martin;D. McCorkle
开发了一种水生涡度协方差（EC）系统，用于测量沉积物 - 水界面上氧气（O₂）和氢离子（H⁺）的交换。该系统使用O₂光学传感器和一种新开发的微流池H⁺离子选择性场效应晶体管；这些传感器显示出足够的精度和足够快的响应时间，能够测量与湍流交换相关的浓度变化。总碱度和溶解无机碳的离散样本被用于确定水柱的背景碳酸盐化学，并将O₂和H⁺通量与底栖过程相关联。ECHOES系统被部署在一个富营养化的河口（沃奎特湾），结果显示底栖生物在白天是酸度的汇，在夜间是酸度的源，H⁺和O₂通量分别为±0.0001和±10毫摩尔每平方米每小时。还使用底栖通量室测定了H⁺和O₂通量，以便与EC速率进行比较。以0.25小时为间隔测定的通量室通量与EC通量共同变化，但幅度约低4倍。这种差异可能是由于通量室内孔隙水平流受到抑制以及封闭通量室上覆水的化学性质发生变化。在每个数据集（EC和通量室）中，单个的H⁺和O₂通量高度相关，并且两种方法得出的H⁺通量都不能仅用O₂代谢来解释。ECHOES系统为确定底栖生物地球化学循环对沿海海洋酸化和碳循环的影响提供了一种新工具。
An aquatic eddy covariance (EC) system was developed to measure the exchange of oxygen (O2) and hydrogen ions (H+) across the sediment‐water interface. The system uses O2 optodes and a newly developed micro‐flow cell H+ ion selective field effect transistor; these sensors displayed sufficient precision and rapid enough response times to measure concentration changes associated with turbulent exchange. Discrete samples of total alkalinity and dissolved inorganic carbon were used to determine the background carbonate chemistry of the water column and relate the O2 and H+ fluxes to benthic processes. The ECHOES system was deployed in a eutrophic estuary (Waquoit Bay), and revealed that the benthos was a sink for acidity during the day and a source of acidity during the night, with H+ and O2 fluxes of ± 0.0001 and ± 10 mmol m−2 h−1, respectively. H+ and O2 fluxes were also determined using benthic flux chambers, for comparison with the EC rates. Chamber fluxes determined in 0.25 h intervals co‐varied with EC fluxes but were ∼ 4 times lower in magnitude. This difference was likely due to suppressed pore‐water advection in the chambers and changes in the chemistry of the enclosed chamber overlying water. The individual H+ and O2 fluxes were highly correlated in each dataset (EC and chambers), and both methods yielded H+ fluxes that could not be explained by O2 metabolism alone. The ECHOES system provides a new tool for determining the influence of benthic biogeochemical cycling on coastal ocean acidification and carbon cycling.