My research is driven by a desire to understand the relationship between ecosystem dynamics and animal populations. As the trophic-dynamic model of whole ecosystems gained favor in the 1960's and 70's, many researchers began to downplay the importance of animals in structuring ecosystems. New interest in the role of animals in ecosystems has been stimulated by work in community ecology that indicated keystone species strongly influence community composition as well as by work on "top-down" controls on productivity. We now know that grazing, predation and physical disturbance by animals can influence a host of processes at the ecosystem level. My research combines the ecosystem perspective of energy and nutrient flows with traditional population and community dynamics.

I am especially interested in the role fish play in aquatic ecosystems. I have examined problems ranging from the importance of fish in exporting nutrients and carbon from estuaries, to the effect of habitat degradation on fish community structure in coastal embayments, to the response of upper trophic levels to increased nutrients in arctic streams. I use a combination of approaches to address these questions ranging from surveys of fish abundance and species composition to traditional gut content analyses as well as state of the art techniques such as measuring of the natural abundance and flows of ¹⁵N tracers in food webs.

Through collaboration with other scientists at the Center, I am also able to assess how animals influence processes like nutrient regeneration. One of my current interests is the ways that animals, through feeding, constructing burrows, or migration can regulate or modify biogeochemical cycles.