Grant: Strategic Projects - Group

Canadian aquatic environments are increasingly stressed as a result of contaminant loads from industry, agriculture and urbanization. Chemicals eventually end up in aquatic environments where biological availability is high. The high level of stress in contaminated aquatic habitats will elicit an adaptive response in the resident fauna: either short-term physiological change (acclimation), genetic change driven by selection (evolution), or both. Such adaptive responses are not considered when we look for population- or ecosystem-level effects of contaminant exposure and may explain the rarity of negative population-level effects. This project examines the response of brown bullhead from contaminated and clean sites to contaminant (PAH) challenges. We propose that the energetic and survival costs of living in contaminated environments drive physiological and genetic changes that maximize the survival of the stressed fish; however, acclimation has high energetic costs and is thus a short-term solution, while evolutionary responses are longer-term solutions that drive other life history changes. Using novel methodologies developed for quantifying contaminant response across levels of biological organization (molecular, cellular, physiological, behavioural, and population) in this model catfish species, we will partition the toxicological stress response into physiological and genetic adaptive components. The goal of the project is to quantify and integrate stress response measures, and generalize our results by estimating the energetic costs of adaptive contaminant responses to explicitly incorporate such costs into a bioenergetic model.We will use integrated interdisciplinary approaches to evaluating population-level effects of contaminated environments to provide regulatory recommendations for contaminated aquatic ecosystems: for example, ecosystems exhibiting primarily acclimation are likely not stable, and immediate intervention would be indicated, while ecosystems exhibiting adaptive genetic change are more stable, and longer term action plans would be appropriate.