We used biotelemetry to monitor monthly adult white crappie locations and core-use-area sizes at Lyndon B. Johnson (LBJ) and Waco reservoirs in Texas over two 6-month periods (December 2000-May 2001 and November 2001-April 2002) and tested whether deploying trap nets at sites near known fish locations and at similar sites predicted to contain fish would result in increased trap-net catch per effort compared to randomly selected sites. No evidence suggested crappie preferred different depths depending upon the time of year in LBJ or Waco reservoirs. We observed fish further from shore in January compared to April in LBJ Reservoir, but all months were similar for Waco Reservoir. The majority of fish locations (>55% for both reservoirs throughout study) were further from shore than our trap nets effectively fish (21.3 m). Trap-net catch rates for the three deployment strategies (known, predicted, and random) were not significantly different in any month (November 2001-April 2002) for LBJ or Waco reservoirs. Selecting sampling sites subjectively offered no significant benefit over selecting sites randomly. However, trap nets set in deeper water (>4 m) typically caught fewer fish at both reservoirs and nets set in the upstream third of Waco Reservoir generally caught greater numbers of adults. Addressing large- and small-scale habitat variables (i.e., linear distance from dam and water depth) may be more important than actual fish locations when deciding on a trap-net deployment strategy.
Fisheries Outstanding Technical Paper