Prediction of dispersal and establishment of aquatic nonindigenous species across Ontario lakes: Linking vector-based and habita

Prediction of range expansion of nonindigenous species is important, as it is often easier to prevent invasions than to mitigate impacts once invasions have occurred. A combination of models for propagule pressure (gravity models) and habitat matching based on lake chemistry and fish communities allow for refined predictions of where species may be expected to disperse and establish. We compare dispersal patterns and mechanisms of the spiny waterflea and the zebra mussel in inland Ontario lakes. We surveyed recreationalists regarding the movement of trailered boats to model vector traffic among lakes, and used this measure of propagule pressure as the first input into a logistic model. Both species are transported overland by mechanisms associated with boating, though differences in dispersal may be influenced by differences in life-history traits, which, in turn, influence the relative importance of different mechanisms. For example, spiny waterflea resting eggs may be transported long-distance on contaminated fishing line, whereas zebra mussel adults may attach to macrophytes entangled on boat trailers. Simulations will be highlighted that illustrate predicted differences in spread based upon dispersal vectors and environmental tolerances.