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

Abstract

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%). I 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 fishery sectors to evaluate the relative magnitude of potential population impacts among these fishery sectors. An estimated 56.1% of Largemouth Bass were captured annually in year 1 of the study at Lake Guntersville and 49.5% in year 2 and 45.8% (year 1) and 30.8% (year 2) at Lake Wheeler. Harvest rates were 4.7% and 5.9% at Lake Guntersville and 2.3% and 2.9% at Lake Wheeler. After accounting for literature-based estimates of post-release mortality, an estimated 8.5% and 10.6% of the Largemouth Bass died due to angling at Lake Guntersville versus 5.4% and 7.8% at Lake Wheeler. Although total capture rates were high, harvest and catch-and-release mortality are likely low enough that the total population impact of recreational angling is low. Tag reporting rates were lower for fish caught in competitive tournaments than that for non-tournament captures. The annual instantaneous tag loss rate of dart tags was 0.037. The tagging induced mortality rate was 0.015 after one month. My results could improve management strategies at heavily fished reservoirs with high rates of voluntary release.