Research on natural microbial communities is positioned at the frontier of both biological and ecological science.  Accumulated knowledge from decades of research demonstrates the central and critical role of bacteria and other microbes in every biogeochemical cycle of every ecosystems on the planet.  However, recent discoveries using new molecular techniques (PCR, DNA sequencing, etc.) are teaching us how little we know about the organisms involved in these processes.  Most microbes in the natural environment have never been grown in the lab or studied as individuals in any way.  Molecular tools are opening up a world of discovery with seemingly limitless possibilities.

My research is focused on microbial communities in aquatic systems; mainly estuaries, rivers and lakes.  But conceptually I place my results in the context of watersheds, and other “ecosystem-scale” units.  This viewpoint is essential when working in open systems like estuaries and rivers where organic matter, nutrients and microbes are transported in and out by the flow of water.  Like many other microbial ecologists, I’m fascinated by the linkages between microbial diversity (who they are) and microbial function (what they do), and I think we can learn a great deal about this by studying how and why the composition of microbial communities varies across environmental gradients and shifts with time in dynamic environments like estuaries, rivers and lakes.

Throughout my career I’ve worked closely with inter-disciplinary teams of scientists to integrate my discoveries with those of my colleagues and to produce more holistic descriptions of ecological systems. I continue to do this today through close collaborations with scientists here at UMCES Horn Point Laboratory and elsewhere, and by working at study sites that support vigorous and varied research programs like Toolik Lake, the Columbia River Coastal Margin, Plum Island Sound, and the Chesapeake Bay.