Vulnerability to angling and survival of Smallmouth Bass in a northern Wisconsin lake
Stephanie L Shaw, Taylor N Preul-Stimetz, Greg G SassAbstract
Objective
Catch-and-release angling can influence survival of Smallmouth Bass Micropterus dolomieu, particularly in small inland lakes, when angler effort is high and fish are repeatedly captured. However, not all fish may be equally vulnerable to capture, which could apportion mortality effects unequally across the population. Our objectives were to (1) assess angler behavior, effort, and catch relative to abundance; (2) estimate survival and probability of capture in relation to fish sex and angler effort; and (3) evaluate vulnerability to capture and refractory periods following catch-and-release events.
Methods
We relied on standardized fisheries-independent surveys to estimate abundance, and we used compulsory creel data to characterize angler behavior and Smallmouth Bass catch rates in Pallette Lake, Wisconsin, during 2015–2025. Beginning in 2021, anglers were asked to record unique tag numbers of Smallmouth Bass that were caught and released. Captures from agency surveys and angler reporting were used to develop individual capture histories for fish and to estimate apparent annual survival and probability of capture. The probability of capture and the refractory period were evaluated in relation to fish characteristics (sex and year-class) and angler effort.
Results
Angler total catch divided by abundance suggested that all Smallmouth Bass could have been caught and released three to seven times in any given year during 2015–2025. Probability of capture for individual Smallmouth Bass increased as effort increased, and the probability was higher for males relative to females. Survival was 80% for males and 83% for females. During the tag reporting period, 42% of tagged Smallmouth Bass were never reported as caught by anglers, while 20% were reported once. The refractory period averaged 31 d and was not related to sex, year-class, or angling year.
Conclusions
Despite high estimated rates of catch and release per individual, the annual survival of Smallmouth Bass in Pallette Lake was relatively high compared with survival reported in other studies. Less than half of the population appeared highly vulnerable to angling, while a large segment of the population was less vulnerable, potentially due to a behavioral or spatial mismatch between bass and anglers. Differences in vulnerability to angling can influence the effects of fishing-related mortality on a population and are especially important to consider in high-effort, high-catch fisheries.