Use of a Catch-Depletion Method to Estimate Population Density of Age-0 Largemouth Bass in Submersed Vegetation

Abstract

Abstract A Leslie catch-depletion method was used to estimate abundance of age-0 largemouth bass Micropterus salmoides in submersed aquatic vegetation. Four 0.11-hectare areas were enclosed with a block net in stands of Eurasian milfoil Myriophyllum spicatum. Young largemouth bass were removed during six to seven successive 10-min intervals by use of DC electrofishing gear. Over time, catch per effort declined linearly with cumulative catch by an order of magnitude. Age-0 largemouth bass population density estimates from the four enclosures were similar to those obtained in a 1.2-hectare vegetated cove treated with rotenone. Catchability coefficients, or the slopes of the regressions between catch per effort and cumulative catch, were similar among enclosures and remained relatively constant over successive electrofishing intervals. The coefficient of variation for mean density, derived by using the catch-depletion method, was 42%, similar to values typically associated with rotenone sampling. This catch-...