AUTHORS: Stephen M. Tyszko, Ohio Department of Natural Resources, Division of Wildlife; Jeremy J. Pritt, Ohio Department of Natural Resources, Division of Wildlife; Richard D. Zweifel, Ohio Department of Natural Resources, Division of Wildlife; Stuart A. Ludsin, The Ohio State University; Joseph D. Conroy, Ohio Department of Natural Resources, Division of Wildlife; Jay Kelly, The Ohio State University; Michael Figueroa, Ohio Department of Natural Resources, Division of Wildlife.
ABSTRACT: Stocking yearling Channel Catfish to mitigate perceived predation by Largemouth Bass has long been the convention despite greater costs compared to stocking smaller life stages. We quantified recruitment of stocked cohorts of Channel Catfish and investigated the effects of stocking life stage (fingerling vs. yearling), Largemouth Bass density (low vs. high), and their interaction on the percentage of a cohort recruiting to the adult population and fishery. Marked (magnetized wire tags) cohorts of advanced fingerling and yearling Channel Catfish were concurrently stocked into reservoirs with low (7 reservoirs, CPUE < 100 fish/h) and high-Largemouth Bass density (5 reservoirs, CPUE > 100 fish/h) populations. We sampled these reservoir Channel Catfish populations with baited, tandem hoop nets 7–8 years after stocking and estimated recruitment. We used a linear mixed model with reservoir as a random effect to test whether cohort recruitment differed by life stage stocked, Largemouth Bass density, or their interaction. Overall, the mean percentage of Channel Catfish recruiting to the adult population and fishery in cohorts stocked as advanced fingerlings was 2.4% (SE = 0.69%) and the mean percentage in cohorts stocked as yearlings was 10.6% (SE = 2.8%). Largemouth Bass density did not have a significant effect on recruitment (P = 0.43) while the effects of stocking life stage (P < 0.001) and the interaction between Largemouth Bass density and stocking life stage (P < 0.003) were significant. The highest recruitment occurred in cohorts stocked as yearlings in reservoirs with high densities of Largemouth Bass. Stocking advanced fingerling Channel Catfish can produce viable year classes in reservoirs with low or high densities of Largemouth Bass. In addition to higher cost, stocking yearling Channel Catfish may result in excessive densities and slow growth.
