Estimating Capture and Mortality Rates of Largemouth Bass at Guntersville and Wheeler Reservoir, Alabama

Catch-and-release angling for largemouth bass (Micropterus salmoides) has substantially increased since the 1980s, yet few studies have assessed the population-level consequences of these activities.  Guntersville and Wheeler Reservoirs, Alabama, are nationally known largemouth bass fishing destinations with high levels of angling effort and high rates of voluntary release (>85%).  We used a variable reward tagging study to estimate rates of capture, release, mortality, and angler reporting of tagged largemouth bass at these reservoirs.  Separate estimates were obtained for non-tournament release, tournament release, and harvest fisheries to evaluate the relative magnitude of potential population impacts among these fishery sectors.  Preliminary results from the first year of the study suggest that 44% of largemouth bass at Guntersville and 31% at Wheeler Reservoir were captured by anglers in 2014.  Harvest rates were 6% at Guntersville and 2% at Wheeler.  Competitive tournaments captured 10% of largemouth bass at Guntersville and 12% at Wheeler.  Tag reporting rates were lower for fish caught in competitive tournaments than that for non-tournament captures.  The estimated instantaneous natural mortality rate was 0.40 yr^-1 and did not differ between reservoirs.  Our results could improve management strategies at heavily fished reservoirs with high rates of voluntary release.