Fate and Transport of Metallic, Radioactive and Organic Contaminants in the Ecosystem

An ecosystem consists of the biological community that occurs in some locale, and the physical and chemical factors that make up its non-living or abiotic environment. There are many examples of ecosystems — a pond, a forest, an estuary, a grassland. The boundaries are not fixed in any objective way, although sometimes they seem obvious, as with the shoreline of a small pond. Usually the boundaries of an ecosystem are chosen for practical reasons having to do with the goals of the particular study.

The study of ecosystems mainly consists of the study of certain processes that link the living, or biotic, components to the non-living, or abiotic, components. Energy transformations and biogeochemical cycling are the main processes that comprise the field of ecosystem ecology. How can we study which of these linkages in a food web are most important? One obvious way is to study the flow of energy or the cycling of elements. For example, the cycling of elements is controlled in part by organisms, which store or transform elements, and in part by the chemistry and geology of the natural world. The term Biogeochemistry is defined as the study of how living systems influence, and is controlled by, the geology and chemistry of the earth. Thus biogeochemistry encompasses many aspects of the abiotic and biotic world that we live in.

My research focuses on understanding transport, fate and bioaccumulation of metals, radioactive elements and organic contaminants in aquatic systems. I have studied a range of contaminants including trace elements (metals, Se, Hg), radioactive elements (Cs, Th), and organo-chlorine pesticides (PCBs, DDT), in a variety of aquatic systems including lakes and reservoirs, wetlands, estuaries and rivers, and in biota ranging in size from zooplankton to diving ducks and sturgeon. These diverse research interests have led me to a greater understanding of how contaminants behave chemically in the environment, interact with biological systems and manifest their effects in nature. Each research area is of sufficient importance and interest to continue dedicated research on them; however, it is how they interact in a larger ecosystem context that I find most intriguing. In the past, the goal of understanding complex environmental problems in nature was seen as unattainable. However, with new tools and combined approaches from a variety of disciplines I believe we will soon be able to develop ecosystem models that accurately depict mechanisms of contamination at all levels of ecosystem organization. It is only through this level of awareness that will we truly be able to understand chemical stressors and protect our environment.