Ecological benefits and toxicological consequences of flooding in river ecosystems

河流生态系统洪水的生态效益和毒理学后果

• 批准号: 434943-2013
• 负责人: Jardine, Timothy
• 金额: $ 1.97万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=631923
• 关键词: Ecological; benefits; toxicological; consequences; flooding

Floods are natural events that are often perceived by the public as uniformly harmful because of their negative effects on human property and in extreme cases, human life. But floods can also indirectly benefit humans via their influence on ecosystem services. The goal of this research is to determine the benefits and consequences of flooding for fish and other animals that live in rivers. It will use a model ecosystem - a series of beaver ponds in the Rocky Mountain foothills of Alberta - and a large, flood-prone delta in the Saskatchewan River to test the hypothesis that shallow, flooded areas of the river have higher rates of primary productivity, produce more and larger fish and have longer food chains than free-flowing sections of the river. These benefits are expected to be offset by higher concentrations of potentially toxic trace elements that result from their liberation from soils and decaying organic matter by floodwaters.My lab will use quantitative sampling in new and old beaver ponds to draw comparisons to free-flowing river reaches and develop models that predict changes in algal, invertebrate and fish productivity at various phases of the flood cycle. Stable isotope ratios of carbon and nitrogen will be used to examine the transfer of algal and detrital organic matter to invertebrates and fishes and assess exposure pathways for trace elements. In the Saskatchewan River delta, we will collect large, old fish and use new microsampling techniques of ageing structures (micromilling, laser ablation inductively-coupled plasma mass spectrometry) to interrogate the past feeding, growth and survival of individual fish and their exposure to trace elements in relation to hydrological conditions in the river. By increasing our understanding of both positive and negative effects of the flood pulse, it will help inform the debate surrounding the restoration of natural flow regimes via dam removal and wetland re-establishment and protection.

洪水是自然事件，由于其对人的财产，在极端情况下对人的生命的负面影响，公众往往认为洪水是一致有害的。但洪水也可以通过对生态系统服务的影响间接造福人类。这项研究的目的是确定洪水对生活在河流中的鱼类和其他动物的好处和后果。它将使用一个生态系统模型--位于阿尔伯塔落基山脉山麓的一系列海狸池塘--以及萨斯喀彻温河中一个大型的易发洪水的三角洲，来检验一个假设，即河流的浅水区，洪水区的初级生产力较高，生产更多更大的鱼，食物链比河流的自由流动部分更长。这些好处预计将被更高浓度的潜在有毒微量元素所抵消，这些微量元素是由洪水从土壤和腐烂的有机物中释放出来的。我的实验室将在新的和旧的海狸池塘中使用定量采样，以与自由流动的河流河段进行比较，并开发模型，预测洪水周期的各个阶段藻类，无脊椎动物和鱼类生产力的变化。碳和氮的稳定同位素比率将用于检查藻类和碎屑有机物质向无脊椎动物和鱼类的转移，并评估微量元素的暴露途径。在萨斯喀彻温河三角洲，我们将收集大型，老鱼，并使用新的微取样技术的老化结构（微磨，激光烧蚀感应耦合等离子体质谱法），询问过去的喂养，生长和生存的个别鱼和他们的接触微量元素在河流中的水文条件。通过增加我们对洪水脉冲的积极和消极影响的理解，它将有助于通过拆除大坝和湿地重建和保护来恢复自然水流系统的辩论。