The Effect of Water Temperature, Angling Time, and Dissolved Oxygen on the Survival of Largemouth Bass Subjected to Simulated Angling and Tournament Handling Procedures

Abstract The Largemouth Bass Micropterus salmoides is the most sought-after species by recreational and tournament anglers in the United States. Survival of angled and tournament-handled Largemouth Bass has been related to numerous factors, but the independent effects of water temperature, angling time, and live-well dissolved oxygen (DO) concentration on survival have not been measured. Understanding the independent effects of these factors on fish survival is necessary to formulate realistic models to predict population effects of catch-and-release and tournament angling throughout the year. Survival responses to water temperature, angling time, and live-well DO concentration are also needed to develop guidelines useful for maximizing survival of released Largemouth Bass. Five-day survival of Largemouth Bass larger than 300 mm was evaluated after simulated catch-and-release and tournament handling (8 h of confinement in aerated live wells and a weigh-in before release) over the range of water temperatures typically encountered by Largemouth Bass anglers (17–33°C) while also testing independent effects of simulated angling time (1 and 3 min), live-well temperature change (∆T = 0, −4, and +4°C), and live-well DO (2.0, 5.5, and 8.5 mg/L). Survival of fish subjected to catch and immediate release was 100% at all temperatures measured, and survival of tournament-caught fish was over 80% at temperatures of 29°C or less but declined at 33°C. Survival decreased with increased simulated angling time at high temperatures and at a DO level of 2.0 mg/L in live wells. Survival rates and probabilities provided in this study should be considered best-case estimates because all fish were handled carefully and not subjected to hook wounding. However, results suggest that high survival of angled and tournament-handled Largemouth Bass is possible with short angling times and appropriate live-well management.