Invasive smallmouth bass (Micropterus dolomieu): History, impacts, and control

In this review, we (i) describe smallmouth bass (Micropterus dolomieu Lacepède, 1802) invasions past, present, and future; (ii) summarize the impact that this species can have on native communities; and (iii) describe and discuss various options for control. M. dolomieu are invasive throughout much of the United States, southern portions of Canada, and in countries in Europe, Asia, and Africa. Historically, this species spread via stocking programs intended to improve sport fisheries. Currently, their spread is facilitated by anglers and global climate change. Models predict that M. dolomieu will continue to spread with consequences for native prey fish, sport fish, and food webs through predation, competition, and hybridization. Effective control methods are necessary to mitigate these impacts. Options for M. dolomieu control include biological control, chemical control, environmental manipulation, and physical removal. However, our review of the literature suggests that only a handful of the possible control options have been explored (usually in isolation and with limited success), and that there is a clear need for focused research and informed management. For example, our elasticity analysis of published M. dolomieu matrix population models suggests that M. dolomieu control will be most effective when it targets eggs, larvae, and juveniles. We recommend targeting these life stages by using nest failure as part of an adaptive and integrated pest management approaches that incorporate existing and emerging technologies. However, we also emphasize that M. dolomieu control, where necessary and possible, is more likely to take the form of suppression rather than permanent eradication. Therefore, we also recommend efforts to prevent M. dolomieu (re)introduction.