Response of a Brown Bullhead Population to Flathead Catfish Introduction in a Small Virginia Impoundment

John Odenkirk
VA Fish & Game, 1320 Belman Rd., Fredericksburg, VA 22401, 540-899-4169, 540-899-4381 (FAX), jodenkirk@dgif.state.va.us

Flathead catfish Pylodictis olivaris were stocked in 1990 and 1994 in a 31 ha Virginia impoundment to control stunted and undesirable fish populations including brown bullhead Ameiurus nebulosus. Changes to the fishery were monitored with creel surveys and gill nets. Brown bullhead harvest decreased from 2285 in 1992 to 25 in 1998. Average weight of harvested brown bullheads increased (rē=0.94; P<0.0001) as population numbers declined. Brown bullheads harvested in 1998 averaged 761g; whereas, those harvested before flathead catfish introduction rarely exceeded 150 g. Brown bullhead catch in gill nets followed a similar trend from 1993 through 1998, and average weight increased (rē=0.86; P=0.02); whereas, catch declined significantly (r2=0.73; P=0.03). Flathead catfish appeared to have effectively controlled brown bullheads in our study lake.