Simulating Largemouth Bass Fishery Responses to Catch-and-Release Angling Mortality

Largemouth bass Micropterus salmoides recreational fisheries are increasingly dominated by catch-and-release (CR) practices.  Recent research indicates that when fishing pressure is high, CR-related mortality may comprise a large portion or majority of overall fishing-related mortality.  CR mortality is a challenge to managers because it is unlikely to be altered by actions such as changing length or bag limits.  We conducted a population survey in 2012 of Mansfield Hollow, a popular bass lake in northeast Connecticut, including a population estimate, creel surveys, and tournament monitoring to characterize the contribution of CR mortality to overall annual mortality vs. purposeful harvest and natural mortality.  We simulated the outcomes of management actions such as length limits, decreased and increased fishing pressure and a range of CR mortality rates on population size structure.  Tournament monitoring and creel surveys indicated that the total number of catch events was 3.9 times higher than the estimated population size, indicating that most individuals are captured more than once.  We estimated CR mortality to represent between 60.4 and 83% of fishing related mortality.  The results of our simulations will inform management actions on highly exploited lakes in the CR era.