Identifying flood- and food-related limits to fish and wildlife production in the Saskatchewan River delta

点击翻译按钮获取中文摘要

In large river basins, water management agencies are responsible for delivering flows to downstream ecosystems. In many cases, extensive dam-building has led to more stable flows, with decreased incidence and severity of high flow events. However, a growing body of research suggests floods may be ecologically important, leading to questions regarding whether flows should be managed to more closely mimic natural flood regimes. This research aims to extend beyond our current knowledge of benefits of dams in terms of water storage for industrial, municipal and agricultural purposes to assess how dams can be operated in a way to achieve positive environmental outcomes, specifically via controlled floods. This project will examine aquatic productivity and food webs following periodic, experimental inundation from a dam spillway, coupled with parallel observations in a natural, flood-prone river delta to determine the value of wetland connectivity in driving fish and wildlife production. The experimental wetland inundation, conducted at the E.B. Campbell Hydroelectric facility in Nipawin, SK, will serve as a model system to examine the biological response to overbank flows that occur further downstream in the Saskatchewan River delta, a region rich in biological productivity, diversity and human history. It will use natural chemical tracers - stable isotope ratios - to link animals to critical areas for feeding, growth and reproduction, and novel techniques to quantify the growth potential of animals, the quality of their food and the stress they experience. Together, these measurements will enhance our understanding of role of the flood pulse in sustaining fish and wildlife populations in northern rivers, and how the timing and magnitude of water delivery might achieve maximum ecological benefits under scenarios of increasing water scarcity and uncertainty.