Analysis of the impact of flathead catfish predation on the abundance of four centrarchid species

The top piscivore in Byllesby Reservoir, a 98.6 ha hydropower impoundment in southwestern Virginia is the flathead catfish Pylodictis olivaris. The most numerically abundant fish in the reservoir are centrarchids, specifically bluegill Lepomis macrochirus, redbreast sunfish L. auritus, smallmouth bass Micropterus dolomieu, and spotted bass M. punctulatus. A bioenergetics model was used to estimate the number of age-l and older centrarchids consumed annually by the flathead catfish population. These estimates were then compared to estimated abundances of each centrarchid species (age-1 and older) in the impoundment, resulting in an estimate of predation impact.