Fishing for Answers: Do Protected Areas Prevent the Selective Removal of the ‘Best’ Largemouth Bass Dads

Abstract

While the use of aquatic protected areas that exclude angling might be considered an evolutionarily-enlightened management approach to dealing with fisheries-induced evolution (FIE), there is little empirical data on the effectiveness of this approach at maintaining the diversity of phenotypic traits within protected areas. In species with parental care, including largemouth bass (Micropterus salmoides), active nest guarding and aggression towards potential brood predators by males may render these individuals particularly vulnerable to capture via angling because of increased propensity to attack fishing lures near their nests. Selective removal of more aggressive individuals by anglers should therefore drive population-average phenotypes towards lower levels of aggression. To assess the effectiveness of protected areas at mitigating FIE, the parental care behaviours of wild, free-swimming male bass were compared during the early nesting period for bass within and outside protected areas. It was found that nesting males within long-standing fishing protected areas (>70 yrs) were more aggressive towards potential nest predators. Males within protected areas were also more likely to strike at artificial fishing lures and more prone to capture during angling events. Collectively, the findings suggest that recreational angling selects for individual bass with lower levels of parental care and aggression,and that the establishment of protected areas may mitigate this potential FIE at the population level. The extent to which this phenomenon is found in other species and systems likely depends on their reproductive strategies, their spatial ecology relative to protected area boundaries, and habitat quality within protected areas.