Impacts of contaminants on aquatic ecosystems

在加拿大，我们的溪流和河流受到一系列点源污染物的影响，包括来自小城市中心、农业、高尔夫球场和草坪农场的径流，以及来自家庭和工业来源的废水排放。安大略省中南部靠近特伦特大学的卡瓦塔湖、加纳拉斯卡湖和西姆科湖流域是研究农业土地利用和城市发展对化学污染物释放的影响及其对河流群落影响的完美天然实验室。在这项研究中，特伦特大学的一组研究人员在Chris Metcalfe教授的指导下，将研究安大略省这一地区的温暖水流，以评估化学污染物是否正在损害有机物质的分解和营养循环，以及是否正在影响小溪流鱼(即斑点鱼)的健康和发育。如果这些影响正在发生，在溪流中使用被动采样器设备进行监测，将使梅特卡夫博士和他的研究生团队能够识别影响水生生物的污染源。一旦确定了污染源，监管机构就可以实施最佳做法来控制或减轻这些污染物的排放，包括河岸带、缓冲地带和湿地的管理、生态恢复和废水处理。这些研究也适用于加拿大其他地区，在那里，更集约化的农业和不断扩大的城市化正在影响我们的水资源。

In Canada, our streams and rivers are impacted by a range of point sources of contaminants, including runoff from small urban centres, agriculture, golf courses and turf farm operations, and discharges of wastewater from domestic and industrial sources. The Kawartha Lakes, Ganaraska and Lake Simcoe watersheds in south-central Ontario near Trent University are a perfect natural laboratory to study the effects of agricultural land use and urban development on the release of chemical contaminants and their effects on stream communities. In this study, a team of researchers from Trent University under the supervision of Prof. Chris Metcalfe will study warm water streams in this region of Ontario to evaluate whether chemical contaminants are impairing the decomposition of organic material and nutrient cycling, and are affecting the health and development of small stream fish (i.e. darter species). If these impacts are occuring, monitoring with passive sampler devices in the streams will allow Dr. Metcalfe and his team of graduate students to identify the sources of contamination that are impacting aquatic organisms. Once the sources have been identified, regulatory agencies can implement best practices to control or mitigate the release of these contaminants, including management of riparian zones, buffer strips and wetlands, ecological restoration and treatment of wastewater. These studies are applicable to other areas of Canada where more intensive agriculture and spreading urbanization are affecting our water resources.