Estimating Largemouth Bass Abundance Using Creel Census and Tournament Data in the Fishing-Success Method

Abstract

The fishing-success or depletion method of calculating abundance was applied to largemouth bass (Micropterus salmoides) data from a 1980 creel survey and bass tournaments on Back Bay, Virginia. Catch-per-unit-effort of all anglers was regressed against total catch after several adjustments of the data. First, recruitment of fish smaller than 305 mm was accounted for by analysis of age and length composition of the catch. Second, catch-per-unit-effort data were adjusted for variation in catchability based on catch rates in bass fishing tournaments. Third, the slope of the regression between catch per unit effort and cumulative catch was adjusted according to similar calculations for a known number of tagged fish in the bay. After all adjustments, the method provided an estimate of about 72,000 largemouth bass longer than 305 mm. This estimate was about 45% lower than the mark-recapture estimate and 70% lower than cove-rotenone estimates. The fishing-success estimate is considered a minimum useful estimate that requires less effort to generate in contrast to other estimation techniques.