Interests

One of my main research focuses is on the fate and effects of persistent contaminants in aquatic biota. I am particularly interested in understanding the factors that affect the concentrations of pollutants in subsistence and sports fisheries as high concentrations of contaminants can be found in predators from remote systems. My research programs have included work on lakes in the Canadian and US Arctic, in temperate regions of Canada (see http://zeus.uwindsor.ca/glier/tsri/index.htm), and in central and southeastern Africa. These studies have examined the accumulation of persistent contaminants (such as mercury, DDT and current-use pesticides) in freshwater food webs and have used stable carbon and nitrogen isotopes to characterize trophic interrelationships and energy flow from primary producers to top predators. My research in the Canadian Arctic, on temperate lakes and in tropical regions has shown that stable carbon and nitrogen isotopes can be broadly applied to understand the trophic transfer of contaminants that are of concern for wildlife and humans consuming fish. The results of these previous and ongoing studies are being used to contrast the fate of persistent pollutants in food webs that differ in their climatic regimes and species composition. There is also emerging evidence that some pharmaceuticals and personal care products are not being completely broken down in the treatment of municipal sewage. Although their effects on aquatic organisms are not well understood, some of these chemicals are being found in sewage outfall and in receiving waters although many have not yet been pursued in environmental compartments. These compounds are designed to be biologically active, and it has been shown that some have adverse impacts on aquatic organisms. One of the studies that I am involved in is a whole-lake synthetic estrogen addition experiment. This long term ecosystem-level study is examining the biochemical- through population-level effects of the potent estrogen mimic used in birth control pills on fish and lower-trophic-level organisms. Results from the experiment will be critical in understanding the risks that estrogen mimics pose to aquatic organisms, and for linking responses across several levels of biological organization.