Comparative Behavior Of Wild Bluegill Captured Inside And Outside Of A Long-Standing Aquatic Protected Area

In recreational fisheries it is understood that individual fish that exhibit bolder personality traits have a tendency to be removed from the population (i.e., fishing mortality via harvest or catch-and-release mortality), while more timid individuals remain. The use of aquatic protected areas (APAs) has been promoted as a means of offsetting the negative consequences that are associated with fishing mortality by protecting the full suite of phenotypes. However, little work has investigated whether APAs are able to maintain heterogeneity in behavioral traits in wild fish. We attempted to address this question by using wild Bluegill Lepomis macrochirus from Lake Opinicon, a freshwater system consisting of both an APA and heavily fished areas. The Bluegill were obtained via angling from three zones in the lake: the main lake area (i.e., fished), the APA (which has been in place since the 1940s), and a transitional zone between these two areas. In the laboratory, the Bluegill were subjected to two behavioral assessments, a Z-maze and a flight-initiation-distance (FID) test, to address differences in boldness and risk-taking between these populations. No significant effects of capture zone were detected for any of the behavioral metrics that were assessed in the maze trial. However, individuals that originated from the main lake population had significantly higher FID scores than the fish from the transitional zone and the APA did, indicating that they were more timid. Our results suggest that fisheries activities may only be acting only on specific traits, which may explain some of the null results that are presented here. Nevertheless, our study provides evidence that APAs are providing a reservoir of less timid individuals, which is consistent with an evolutionarily enlightened management strategy.