Induced nest failure as a method for controlling invasive bass

Background/Question/Methods

The spread of smallmouth (Micropterus dolomieu) and largemouth bass (Micropterus salmoides) beyond their native range is impacting individual species (e.g., sport and prey fishes) and entire food webs. Few management options have been tested for invasive bass, and those that have tend to be ineffective and inefficient. Using an age-structured model, we evaluate the efficacy of bass control via catch-and-release angling during the nesting season. Our hypotheses are that angling will induce nest failure via predation and abandonment, and that releasing angled adults will prevent conspecific competitive release. We are further testing these hypotheses with small lake experiments which assess our ability to induce nest failure via angling.

Results/Conclusions

Provided that failure is induced in a sufficient proportion of nests each year, our simulations suggest that induced nest failure can result in a smaller population of trophy bass that should have a relatively small impact on native species. When combined with some type of harvest, such as electrofishing, bass abundance further declines. In the scenarios tested, nest failure is able to prevent conspecific competitive release. Field trials suggest that it is possible to angle enough bass to induce sufficient levels of nest failure, dependent on the aggression of the bass in the population. We recommend this strategy to fisheries managers who are interested in efficiently and effectively controlling bass through stakeholder involvement.