Our research evaluates the causes and consequences of biodiversity changes in marine ecosystems, including studies showing how nutrients, consumers, and stress modify diversity in marine communities and how species diversity and identity affect key biogeochemical processes. We are interested in how an interdisciplinary approach to biology, which explores the linkages between processes at different levels of biological organization, can enhance our understanding of how natural systems work. Our biodiversity research is one example of this perspective. We study the processes that influence diversity change at the community level, but then take an ecosystem approach in asking how the diversity and identity of organisms influences their roles in mediating the transformation and flux of energy and matter. A related aspect of our work asks how consumers influence the supply of nutrients to primary producers in marine ecosystems.