Cooperative Fish and Wildlife Research Units Program: Alabama
Education, Research and Technical Assistance for Managing Our Natural Resources

The coupling of climate uncertainty and increasing water demands for multiple uses presents challenges for provision of suitable instream water quality conditions for natural resources. The diversity of aquatic organisms in the southeastern US presents a major challenge when trying to set reasonable and effective temperature and dissolved oxygen requirements. A temperature regime tolerated by one species may be stressful or fall outside the range of tolerance to another. An innovative approach-electron transport system assay (ETS)-has been recently proposed by researchers that could be used as a screening tool to determine and compare optimal and stressful thermal regimes among species. It provides a quantitative measure of the potential oxygen consumption rate of an organism if all enzymes function maximally and the relation between ETS enzyme activity and temperature may be used as an indicator of thermal tolerance for some species. Therefore this project is evaluating ETS as a screening tool to distinguish among organisms with varying tolerance levels. Results will be of great value to Alabama Department of Conservation and Natural Resources, USFWS and private dam operators as it will provide quantitative evidence as to whether measured temperature regimes below dams provide non-stressful conditions, especially for species of interest. These data could inform decisions for modification of flow releases in order to minimize stress to downstream organisms and inform decisions relative to flow regulations associated with dam relicensing.