Use Of Trawl CPUE Data To Forecast Black Crappie Fishery Strengths

Black crappie Pomoxis nigromaculatus support some of Florida’s largest and most popular freshwater fisheries.  However, angler effort, catch, and harvest of black crappie are often highly variable from year to year at many systems throughout Florida, and in other states.  This variability has been labeled as ‘boom-or-bust’, and has been contributed to erratic year class strengths driving fisheries.  We used multiple years of creel survey results and trawl catch data (age and length) collected at Lochloosa Lake, to develop simple linear regression models to investigate if trawl CPUE’s could be used as a tool to forecast the recreational crappie fishery. The relationship between CPUE of crappie > age-1 and creel estimates for angler effort, catch, and harvest over a year later were all significantly positive (angler effort: R²= 0.6576; P < 0.008; angler catch: R²= 0.9003; P < 0.0001; angler harvest: R² = 0.7149; P = 0.004).  The relationship between CPUE of crappie > 229 mm TL and angler harvest data 3 to 4 months later was also significantly positive (R²= 0.6417; P = 0.005).  These relationships suggest that our trawl samples can be useful for forecasting crappie fishery strength in the near future and over a year