Quantifying Metabolically Driven pH and Oxygen Fluctuations in US Nearshore Habitats at Diel to Interannual Time Scales
Quantifying Metabolically Driven pH and Oxygen Fluctuations in US Nearshore Habitats at Diel to Interannual Time Scales
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DOI：
10.1007/s12237-017-0321-3
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发表时间：
2018-06-01
影响因子：
2.7
通讯作者：
Smith, Erik M.
中科院分区：
文献类型：
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作者：
Baumann, Hannes;Smith, Erik M.
我们汇编和检查了15年（2002-2016）的高频监测数据，从国家河口研究储备系统（NERRS），以表征昼夜到年际变化的pH值和溶解氧（DO，%饱和度）在16个不同的，浅水栖息地沿着美国大西洋，墨西哥湾，加勒比海和太平洋沿岸。我们问这些系统是否表现出一个共同的pH/DO的关系，是否有可检测的年际变化趋势，温度，pH值和DO内和跨系统，以及如何pH/DO动态将涉及到营养素和叶绿素的测量水平。我们的分析证实，大，代谢驱动，因此并发的pH值和DO的波动是一个统一的功能近岸栖息地。此外，我们推导出良好的约束关系，预测（i）月平均pH值或（ii）平均昼夜pH值波动系统的基础上栖息地平均盐度和（i）平均DO或（ii）平均昼夜DO波动。这表明，共同的代谢原理驱动昼夜季节pH/DO的变化，以及跨河口环境的多样性。每年的pH值和溶解氧异常并没有表现出单调的趋势，在研究期间，网站和地区之间的差异很大。然而，每周异常的平均值，昼夜最小值，昼夜范围的pH值和DO随着时间的推移显着变化，并强烈相关的温度异常。这些一般模式提供了强有力的经验支持的概念，沿海酸化，除了被驱动的富营养化和大气CO2的增加，是加剧变暖，可能通过增加社区呼吸。营养和叶绿素动态呈负相关，在这些浅，混合良好的系统，但较高的营养水平仍然与较低的pH值和较低的DO水平，在大多数，但不是所有的系统。我们的分析强调了近岸栖息地的特殊动态和NERRS及其全系统监测计划的至关重要性。
We compiled and examined 15 years (2002-2016) of high-frequency monitoring data from the National Estuarine Research Reserve System (NERRS) to characterize diel to interannual variability of pH and dissolved oxygen (DO, % saturation) across 16 diverse, shallow-water habitats along the US Atlantic, Gulf of Mexico, Caribbean, and Pacific coasts. We asked whether these systems exhibit a common pH/DO relationship, whether there were detectable interannual trends in temperature, pH, and DO within and across systems, and how pH/DO dynamics would relate to measured levels of nutrients and chlorophyll. Our analyses confirmed that large, metabolically driven, and thus concurrent fluctuations of pH and DO are a unifying feature of nearshore habitats. Moreover, we derived well-constrained relationships that predict (i) monthly mean pH or (ii) mean diel pH fluctuations across systems based on habitat mean salinity and (i) mean DO or (ii) mean diel DO fluctuations. This suggests that common metabolic principles drive diel to seasonal pH/DO variations within as well as across a diversity of estuarine environments. Yearly pH and DO anomalies did not show monotonous trends over the study period and differed considerably between sites and regions. However, weekly anomalies of means, diel minima, and diel ranges of pH and DO changed significantly over time and were strongly correlated to temperature anomalies. These general patterns lend strong empirical support to the notion that coastal acidification-in addition to being driven by eutrophication and atmospheric CO2 increases-is exacerbated simply by warming, likely via increasing community respiration. Nutrient and chlorophyll dynamics were inversely related in these shallow, well-mixed systems, but higher nutrient levels were still associated with lower pH and lower DO levels in most, but not all, systems. Our analyses emphasize the particular dynamics of nearshore habitats and the critical importance of NERRS and its system-wide monitoring program.