Use of a Fish Bioenergetics Model to Evaluate Effects of Dissolved Oxygen Mitigation at Norris Dam

The management of tailwater fisheries, aquatic ecosystems, and hydropower can have conflicting objectives. For example, the installation and operation of hydroelectric facilities affect downstream biological resources by changing flow regimes, temperatures, and water quality. Special interest groups vigorously support and promote each of these resources: tailwater sport fisheries, which enhance the economic and cultural life of a region; natural aquatic ecosystems, which contribute to biological diversity; and hydroelectric power, which can boost economic growth. Conflicts among these interests may multiply in the next 3 years as the licenses of hundreds of hydroprojects in the nation expire and applications for relicense are evaluated for renewal. When the physical costs to each resource can be presented in quantitative terms and the basis on which these costs are determined is available to review, all parties can benefit because many different solutions can be examined and their consequences quantified. This paper shows how a fish growth model influenced by environmental conditions such as water temperature and dissolved oxygen concentrations can be used to generate information about the costs and benefits of different hydropower development and mitigation scenarios. Models can provide defensible, objective, and accessible insight into outcomes of different development, mitigation, or non-development decisions. This research is conducted as part of the Environmental Mitigation Study of the US Department of Energy's Hydropower Program.