U.S. Geological Survey New Jersey Water Science Center, Lawrenceville, NJ 08648, USA.
Devereux Consulting, Inc, Silver Spring, MD 20901, USA.
Sci Total Environ. 2021 Jun 20;774:145687. doi: 10.1016/j.scitotenv.2021.145687. Epub 2021 Feb 9.
If not managed properly, modern agricultural practices can alter surface and groundwater quality and drinking water resources resulting in potential negative effects on aquatic and terrestrial ecosystems. Exposure to agriculturally derived contaminant mixtures has the potential to alter habitat quality and negatively affect fish and other aquatic organisms. Implementation of conservation practices focused on improving water quality continues to increase particularly in agricultural landscapes throughout the United States. The goal of this study was to determine the consequences of land management actions on the primary drivers of contaminant mixtures in five agricultural watersheds in the Chesapeake Bay, the largest watershed of the Atlantic Seaboard in North America where fish health issues have been documented for two decades. Surface water was collected and analyzed for 301 organic contaminants to determine the benefits of implemented best management practices (BMPs) designed to reduce nutrients and sediment to streams in also reducing contaminants in surface waters. Of the contaminants measured, herbicides (atrazine, metolachlor), phytoestrogens (formononetin, genistein, equol), cholesterol and total estrogenicity (indicator of estrogenic response) were detected frequently enough to statistically compare to seasonal flow effects, landscape variables and BMP intensity. Contaminant concentrations were often positively correlated with seasonal stream flow, although the magnitude of this effect varied by contaminant across seasons and sites. Land-use and other less utilized landscape variables including biosolids, manure and pesticide application and percent phytoestrogen producing crops were inversely related with site-average contaminant concentrations. Increased BMP intensity was negatively related to contaminant concentrations indicating potential co-benefits of BMPs for contaminant reduction in the studied watersheds. The information gained from this study will help prioritize ecologically relevant contaminant mixtures for monitoring and contributes to understanding the benefits of BMPs on improving surface water quality to better manage living resources in agricultural landscapes inside and outside the Chesapeake Bay watershed.
如果管理不善，现代农业实践可能会改变地表水和地下水质量以及饮用水资源，从而对水生和陆地生态系统产生潜在的负面影响。接触源自农业的污染物混合物有可能改变生境质量，并对鱼类和其他水生生物产生负面影响。特别是在美国各地的农业景观中，注重改善水质的保护措施的实施继续增加。本研究的目的是确定土地管理行动对五个切萨皮克湾农业流域中污染物混合物主要驱动因素的影响，切萨皮克湾是北美大西洋沿岸最大的流域，二十年来一直在记录鱼类健康问题。采集并分析了 301 种有机污染物的地表水，以确定旨在减少营养物质和沉积物进入溪流的最佳管理实践（BMP）的实施效果，同时减少地表水的污染物。在所测量的污染物中，除草剂（莠去津、甲草胺）、植物雌激素（芒柄花素、染料木黄酮、雌马酚）、胆固醇和总雌激素（雌激素反应指标）的检出频率足以与季节性水流效应、景观变量和 BMP 强度进行统计比较。尽管这种效应在不同季节和地点因污染物而异，但污染物浓度通常与季节性溪流流量呈正相关。土地利用和其他利用率较低的景观变量，包括生物固体、粪便和农药施用以及产生植物雌激素的作物比例，与站点平均污染物浓度呈反比。BMP 强度的增加与污染物浓度呈负相关，表明 BMP 在研究流域减少污染物方面具有潜在的共同效益。本研究获得的信息将有助于为监测确定具有生态相关性的污染物混合物，并有助于了解 BMP 对改善地表水质量以更好地管理切萨皮克湾流域内外农业景观中生物资源的益处。
