Water is found in many places beyond stream channels throughout the watershed. Streamwater, groundwater, soil water, and water in sediments below the channel contain a rich array of organic carbon molecules important as food for microorganisms and as resources for other living things. This laboratory works on identifying the presence of these molecules and determining their role in the stream ecosystem.
Healthy streams often support 200 - 300+ species of aquatic insects, crustaceans and other invertebrates, forming a rich and complex biological community. This laboratory studies factors that affect the distribution and abundance of aquatic invertebrates, the functional role of invertebrates in stream and river ecosystems, and how these invertebrate communities respond to human activities in temperate and tropical watersheds.
Fish Molecular Ecology
This laboratory works to determine why fish in streams have the distributions they do. Our research includes field studies of fish movement, species composition and productivity; genetic studies of population structure; laboratory studies of tolerance limits to chemical, physical and biological factors; as well as mathematical modeling of population dynamics.
Water and sediment interact to create river channel habitats, floodplains and other elements of the physical riverscape that form the basis of river ecosystems. Our lab studies the movement of water, sediment, organic matter, nutrients and other molecules through watersheds to better understand watershed hydrology, geomorphology and biogeochemistry. We also investigate how watershed land use and river channel restoration practices influence hydrologically mediated processes such as surface-groundwater interaction, sediment transport, and channel evolution.
Microbial life such as bacteria, fungi, and algae are integral to a naturally functioning aquatic ecosystem. By applying comprehensive molecular approaches, this laboratory is focused on characterizing the composition and distribution of microbial communities, and determining the functional roles as well as their interactions with environments.
Organic and Isotope Geochemistry
The complex mixture of organic molecules in streams and rivers holds clues about a wide variety of natural and human processes occurring within watersheds. By determining the identity and origin of these molecules, the scientists in this laboratory can both expand scientific understanding of natural cycles of energy (carbon) and nutrients within the ecosystem and inform decision-makers about the sources and impact of human contamination on water quality.