Ecosystem level assessment of environmentally based flow restrictions for maintaining ecosystem integrity: a comparison of a modified peaking versus unaltered river

摘要: Although dams have impounded the majority of world's altered watercourses, there is a growing awareness importance mitigating or reversing some negative effects on aquatic ecosystems and related services they provide. We used an ecosystem approach, including detailed studies hydrology, geomorphology, invertebrates, fish, food web dynamics river by waterpower production natural flowing to assess system responses change in flow regime (specifically ramping rate flow). was significant alteration sediment regimes under original restricted regime, differences many biotic variables two rivers were not total invertebrate abundance diversity, fish biomass, condition, length. However, distribution sensitive taxa diversity observed between as energy base web, measured with stable isotopes. The had lower overall Odonata, Ephemeroptera Plecoptera, Diptera, Trichoptera, Ephemeroptera, Coleoptera increase towards deeper higher velocity thalweg. On average, δ13C values lighter sites compared unaltered sites, likely due carbon export from upstream reservoir. Results will inform Canadian federal provincial policy concerning efficacy restrictions tool mitigate environmental impacts associated peaking dam operations. Copyright © 2010 John Wiley & Sons, Ltd. Crown right Canada