Experimental determination of ramping rate effects on downstream biota: Magpie River, Ontario

点击翻译按钮获取中文摘要

Canada is the worlds largest producer of hydro-electric power, with more than 230 plants. Two-thirds of domestic electricity comes from hydro and Canada is a world leader in the development and management of hydro-electric facilities. Key to effective management is knowledge and minimization of the ecological effects of operation. To date there has been little study of the ecological effects of ramping, sudden changes in the rate of water release from dams to meet rapid increases in electric demand, on river ecosystems downstream of dams. The research proposed here aims to test whether regulating ramping rates can provide ecological benefits, while at the same time minimizing operator production losses. Ramping rate restrictions are believed to result in harm reduction including: loss of downstream diversity, habitat degradation, changes in sediment input and river temperature regimes. The study proposed here will experimentally compare a period of ramping rate restriction to unlimited ramping and determine how fish living in the river are affected by examining changes in individual growth rates, condition and the water temperatures used by resident fish. In addition, changes in the structure of the river foodweb will also be examined to determine if unrestricted ramping simplifies the foodweb and significantly alters fish diets and dependence on prey. To conduct the work cutting edge stable isotope methods that facilitate determining the water temperatures and prey used by fish will be both used and developed. Results of study in the experimental river will be contrasted to a parallel study of a control river that has no dam to determine how ramping changes the river ecosystem as a whole. The research addresses the need for new experimental approaches to advance scientific understanding at scales relevant to whole-river management by using controlled river flow manipulations and placing emphasis on cooperative interactions among scientists, industry and resource managers, all of whom will participate at some level in the research. Thus, the research will provide practical information and suggest and test new tools for habitat and fisheries managers in relation to ramping and the use of ramping rates for river ecosystem protection.