Department of Earth and Environment, Florida International University, Miami, FL 33199, USA.
Institute of Environment, Florida International University, Miami, FL 33199, USA.
Int J Environ Res Public Health. 2021 Sep 6;18(17):9417. doi: 10.3390/ijerph18179417.
Anthropogenic developments in coastal watersheds cause significant ecological changes to estuaries. Since estuaries respond to inputs on relatively long time scales, robust analyses of long-term data should be employed to account for seasonality, internal cycling, and climatological cycles. This study characterizes the water quality of a highly managed coastal basin, the St. Lucie Estuary Basin, FL, USA, from 1999 to 2019 to detect spatiotemporal differences in the estuary's water quality and its tributaries. The estuary is artificially connected to Lake Okeechobee, so it receives fresh water from an external basin. Monthly water samples collected from November 1999 to October 2019 were assessed using principal component analysis, correlation analysis, and the Seasonal Kendall trend test. Nitrogen, phosphorus, color, total suspended solids, and turbidity concentrations varied seasonally and spatially. Inflows from Lake Okeechobee were characterized by high turbidity, while higher phosphorus concentrations characterized inflows from tributaries within the basin. Differences among tributaries within the basin may be attributed to flow regimes (e.g., significant releases vs. steady flow) and land use (e.g., pasture vs. row crops). Decreasing trends for orthophosphate, total phosphorus, and color and increasing trends for dissolved oxygen were found over the long term. Decreases in nutrient concentrations over time could be due to local mitigation efforts. Understanding the differences in water quality between the tributaries of the St. Lucie Estuary is essential for the overall water quality management of the estuary.
人为开发沿海流域会导致河口生态发生重大变化。由于河口对输入物质的响应时间相对较长，因此应该采用长期数据的稳健分析方法来考虑季节性、内部循环和气候周期。本研究对美国佛罗里达州圣卢西亚河口流域进行了水质特征描述，该流域是一个高度管理的沿海流域，从 1999 年到 2019 年，以检测河口及其支流的水质时空差异。由于该河口与奥基乔比湖人工相连，因此它从外部流域接收淡水。1999 年 11 月至 2019 年 10 月期间每月采集的水样采用主成分分析、相关分析和季节性 Kendall 趋势检验进行评估。氮、磷、颜色、总悬浮物和浊度浓度具有季节性和空间变化。奥基乔比湖的流入物以高浊度为特征，而流域内支流的流入物则以高磷浓度为特征。流域内各支流之间的差异可能归因于流量模式（例如，大量释放与稳定流）和土地利用（例如，牧场与作物轮作）。在长期内，发现正磷酸盐、总磷和颜色呈下降趋势，溶解氧呈上升趋势。随着时间的推移，营养物浓度的降低可能是由于当地的缓解措施。了解圣卢西亚河口各支流之间的水质差异对于河口的整体水质管理至关重要。
