Predicting the impacts of species invasions in aquatic systems

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Biological invasions are a disruptive stressor that is becoming increasingly frequent in freshwater and marine systems worldwide. The longterm goal of my research program is to develop a predictive understanding of the factors that determine the success and impact of invasive species in aquatic environments. My lab will pursue three major lines of research over the next five years. We will investigate: (1) how community-level impacts (e.g. extinctions) caused by invasive species vary with environmental conditions; (2) whether the success and impact of an invasive species can be predicted from its life history traits; and (3) whether the impacts of invasive species are predictable across a range of habitat types and spatial scales. These investigations will involve a combination of experimental studies and statistical analyses of data from documented invasions worldwide. A series of field experiments in the St. Lawrence River will investigate the factors that determine the replacement of one dominant invader by another. On canal walls, we will clear patches of competing Eurasian mussels (the zebra mussel and the quagga mussel) at multiple sites and across multiple depths, and subsequently monitor patterns of recolonization and subsequent species dominance of cleared patches over time and how these patterns vary temporally and spatially. Another series of experiments will examine the influence of zebra mussel colonies on the diversity of benthic invertebrates at small spatial scales. We will also investigate how antagonistic interactions (mutual predation) between a native and invasive crustacean vary across water chemistry gradients, so as to reveal the conditions in which one species or the other dominates. Finally, using meta-analytical techniques, we will examine a global dataset of bivalve invasions to determine if there are predictable patterns of impact that can be related to the life history characteristics of a species, the composition of the invaded community, and the physical characteristics of the invaded habitat. Together, these studies aim to produce useful generalizations and predictive models that are currently lacking for aquatic invasions.