Integrating Fish Bioenergetics and Volitional Movement in Water Quality and Hydrodynamic Models

The integration of fish bioenergetics models and volitional fish movement models with hydrodynamic models is a practical step forward in understanding how management changes in a water body system affect fish habitat and growth. This paper reviews incorporation of fish bioenergetics and habitat models and fish volitional movement models in several reservoirs throughout the USA.Lake Roosevelt with its 230 km long pool is located in northeastern Washington State. The Project provides hydropower, irrigation, flood control, and sport fishing. The reservoir’s 45-day mean residence time is much shorter than a typical lake. The spring freshet requires drawdowns of up to 20 m for flood control. A two-dimensional hydrodynamic and water quality model, CE-QUAL-W2 (Cole and Wells, 2013), was coupled with a fish bioenergetics model based on the Stockwell and Johnson (1999) model to examine the effects of management strategies on the algae-zooplankton-kokanee food web(McKillip, 2007; McKillip and Wells, 2006).Chester Morse Lake, located in central western Washington, is a key source of drinking water for the city of Seattle. The lake and its tributaries are also home to native bull trout, a species currently listed as “threatened” under the Endangered Species Act. A hydrodynamic and temperature model, CE-QUAL-W2 (Cole and Wells, 2013), was developed for Chester Morse Lake, WA. This water quality model was coupled with a fish habitat and bioenergetics model for bull trout (Wells and Wells, 2012; Wells, 2012). This tool was designed to allow managers and operators to estimate the impact on fish habitat and growth potential from various management decisions including extent of drawdown, timing/volume of flows, and pumping operations.Examples of a fish volitional movement model were shown based on temperature, velocity and dissolved oxygen gradients in Brownlee Reservoir on the Snake River system and J. Strom Thurmond Reservoir in Georgia/South Carolina (Nestler et al. 2002).