Creating tools to predict the ecological mechanisms of stressor effect and recovery in freshwater systems.

加拿大的淡水资源可能因人类对景观的活动而受到各种污染物（化学和生物）的损害。这些包括农药、人类和兽医用药物、营养物质，以及我们最近了解到的携带抗生素耐药基因（ARGs）的生物体。这些压力源可对人类健康和生态结构与功能构成重大风险。地表水中这些污染物的两个最常见来源是城市污水排放和一般农业；这两项活动在可预见的未来都不会停止。因此，我们需要了解和预测这些污染物如何影响水质，并探索减轻其释放和影响的解决方案。我的实验室的长期研究目标是了解化学和非化学压力源诱导水生生态系统变化的生态机制。有了这一发现，我们将研究浮游动物和底栖无脊椎动物在通过放牧压力从环境中清除不需要的抗生素耐药生物，特别是来自废水和农业投入的生物，以及初级生产者、营养物质和杀虫剂对这种关系的影响。一种新的工具（换壳酶、壳聚糖酶）将被用于预测无脊椎动物的结构（丰度和生物量）和功能（即ARG放牧），作为评估这种生态服务和次生生产系统状况的一种手段。通过定义和理解毒性和恢复潜力的生态机制（并创造工具来测量和预测这些变化，即生物标志物的影响），我们可以权衡证据，以确定压力源是否具有显著的生物效应。这项工作对使用处理湿地来处理泻湖处理过的废水有影响，特别是在当地生态适宜的环境下，即加拿大大草原，在那里农村污水的被动处理是常态，就像在全球许多地区一样。具体而言，它将直接告知人工湿地与ARGs衰减相关的设计特征和管理方法。因此，这项工作将有助于改善地表水质量，减少人类和生态风险，并更好地了解这些系统的生态和服务。

Freshwater resources in Canada can be impaired by any number of contaminants (chemical and biological) as a result of human activities on the landscape. These include pesticides, human and veterinary-use pharmaceuticals, nutrients, and as we are recently learning, organisms bearing antibiotic-resistant genes (ARGs). These stressors can pose significant risks to both human health and ecological structure and function. The two most common sources of these contaminants to surface waters are release of municipal wastewater effluent and agriculture in general; two activities that will not cease in the foreseeable future. Therefore, we need to understand and predict how these contaminants can impact water quality, and explore solutions to mitigate their release and effects. My laboratory’s long-term research objective is to understand the ecological mechanisms by which chemical and non-chemical stressors can induce change(s) in aquatic ecosystems. With this Discovery, we will investigate the role of zooplankton and benthic invertebrates in removing undesirable antibiotic resistance-bearing organisms, especially those from wastewater and agricultural inputs, from the environment via grazing pressure, and the influence of primary producers, nutrients, and pesticides on this relationship. A new tool (the molting enzyme, chitobiase) will be used in attempts to predict invertebrate structure (abundance and biomass) and function (i.e., ARG grazing), as a means by which to assess the status of systems around this ecological service and secondary production in general. By defining and understanding ecological mechanisms of toxicity and potential for recovery (and creating tools to measure and predict these changes, i.e., biomarkers of effect), we can weigh the evidence to determine whether a stressor is having a significant biological effect. The work has implications for the use of treatment wetlands for polishing wastewater treated in lagoons, particularly those under a local, ecologically appropriate context, i.e., the Canadian Prairies, where passive treatment of rural sewage is the norm, as it is in many regions globally. Specifically, it will directly inform design features and management approaches in constructed wetlands as related to attenuation of ARGs. Thus, this work will contribute to improving surface water quality, reducing human and ecological risks, and a better understanding of the ecology and services of these systems.