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Predicting introduction, establishment and potential impacts of smallmouth bass

Sharma, Sapna, Herborg, Leif-Matthias, Therriault, Thomas W.
Diversity & distributions 2009 v.15 no.5 pp. 831-840
Micropterus dolomieu, climate, economic impact, ecosystems, environmental factors, fish communities, habitats, humans, hydrochemistry, indigenous species, lakes, models, prediction, regression analysis, risk, salmon, trout, British Columbia, Ontario
The introduction of non-indigenous species has resulted in wide-ranging ecological and economic impacts. Predictive modelling of the introduction and establishment of non-indigenous species is imperative to identify areas at high risk of invasion to effectively manage non-indigenous species and conserve native populations. Smallmouth bass (Micropterus dolomieu), a warm water fish species native to central North America has negatively impacted native fish communities, including cyprinids and salmonid populations, as a result of intentional introductions. We predicted the introduction risk; species establishment based on habitat suitability; identified lakes at high risk of invasion; and finally assessed the consequential impacts on native salmon, trout and cyprinid populations. Ontario and British Columbia, Canada. Classification tree and logistic regression models were developed and validated to predict the introduction and establishment of smallmouth bass for thousands of lakes. Densely human populated areas and larger lake surface areas successfully identify lakes associated with the introduction of smallmouth bass (introduction model) in British Columbia. Climate, lake morphology and water chemistry variables were the driving environmental parameters to define suitable smallmouth bass habitat (establishment model). A combination of the introduction and establishment model identified 138 lakes that are currently at risk in British Columbia to the introduction and establishment of smallmouth bass. Of these 138 high-risk lakes, 95% of them contain at least one species of salmon, trout or cyprinid, thereby increasing the potential impact of an invasion by smallmouth bass. Our framework can be applied to other terrestrial and aquatic species to obtain a better understanding of the potential risk posed by a non-indigenous species to an ecosystem. Furthermore, our methodology can be used to focus management efforts on areas at higher risk (e.g. number of potential releases, more favourable habitats) to control future introductions of non-indigenous species, thereby conserving native populations.