Gretchen joined the department of Environmental Resources at IHE Delft in May 2010. Her research activities are focused on understanding the role of aquatic and wetland ecosystems in maintaining water quality in the context of land use and climate change.
Because coastal eutrophication is a serious global problem, she is especially interested in landscape and hydrologic factors that control nitrogen and organic carbon export from human-impacted basins. Most recently she has examined the role of wetlands in the northeast U.S. in controlling nitrogen retention in an urban basin and, in a possible trade off, a source of organic material to downstream ecosystems. One of her main interests is understanding how dissolved organic carbon quality varies with land use, and how it may in turn affect denitrification potential and other ecosystem processes due to variation in lability. She uses a combination of empirical and mass-balance approaches in her research.
Gretchen has worked in arctic, temperate, and tropical regions. In addition to the work described above, she has also conducted research on nutrient and grazing controls of nitrogen fixation in nitrogen limited lakes and streams. Other research has focused on the role of fish distribution in controlling food web structure in arctic lakes and the effects of eutrophication on fish community structure in temperate coastal marine ecosystems.
She has taught undergraduate and graduate courses in Aquatic Ecosystems (focused on biogeochemistry and ecosystem processes), Watershed and Water Quality Management, Stream Ecology, Limnology, Science Writing, as well as many seminar courses focused on special topics.
Before joining IHE, she was a Research Scientist in the Water Systems Analysis Group, Complex Systems Research Center at the University of New Hampshire (U.S.) and a post-doctoral researcher at the Department of Natural Resources at the same university (2005 - 2010).
She earned her Ph.D. (2006) from Cornell University in Ithaca, New York (U.S.) in the Biogeochemistry Program. Her M.S. (1998) was from the University of Minnesota (U.S.) in Water Resources. Her B.A. degree (1993) from Boston University (Massachusetts, U.S.) was in Biology with a specialization in Marine Science (Program at the Marine Biological Laboratory, Woods Hole, MA.)