Shimon C. Anisfeld
Senior Lecturer and Research Scientist in Water Resources and Environmental Chemistry
Research Statement
My research aims to understand human impacts on streams and wetlands, especially in urban coastal environments, with the goal of using this information to improve our management of watersheds.Nutrients and tidal wetland loss
Many coastal areas have experienced significant loss of tidal wetlands, and this problem is expected to increase in severity as climate change leads to an acceleration in sea level rise. Tidal marsh drowning has been observed at several sites on Long Island Sound, but the mechanisms and causes of this marsh loss are poorly understood. We are testing the hypothesis that excessive loading of nutrients (N or P) plays a role in causing marsh loss, either through a decrease in belowground production or through an increase in belowground decomposition. The project involves both observational and experimental components. In the first, we are examining marsh processes (productivity, elevation change, decomposition) in 3 marshes with different nutrient loadings. In the second, we have established fertilization plots in order to determine the effects of added nutrients on marsh processes.
Tidal wetland loss in the Quinnipiac River, CT
We have been studying vegetation loss within the Quinnipiac River brackish marshes, with the goal of understanding the extent, mechanism, and causes of this problem. We have quantitated the changes in marsh vegetative cover over the last 30 years; these involve both mudflat development and a shift in dominance from Typha glauca (cattail) to Phragmites australis (common reed). We are currently collecting data on water levels, marsh surface elevation, salinity, and sediment accumulation rates, in order to assess the mechanism and causes for the vegetation loss. We are also interested in understanding the implications of wetland loss for water quality in the Quinnipiac River and Long Island Sound.
Stream water quality
I have begun a long-term project to regularly collect samples from streams around the state of CT that drain watersheds of different sizes and land uses. The samples are being analyzed for bacterial indicators and nutrients, and will represent a valuable data set for understanding what controls the spatial and temporal variability in stream water quality.
Isotopic studies of sources of nitrogen to Long Island Sound
Arguably the most important problem facing Long Island Sound is nitrogen enrichment and its various manifestations (hypoxia, loss of seagrasses, etc.). We are using an isotope signature approach to estimate the relative importance of different nitrogen sources (e.g., sewage, atmospheric deposition) in two rivers draining to Long Island Sound.
Requirements for stream water quality monitoring
Rivers are dynamic ecosystems in which both water quantity (streamflow) and water chemistry change substantially over a variety of time scales. This variability must be taken into account in planning sampling programs designed to assess the health of a given river. We have collected a high-resolution data set on levels of bacterial indicators (Escherichia coli) and nutrients at a riverine site. We are now using this dataset to evaluate the likelihood that the state’s current water quality sampling program (8-12 samples per year) accurately reflects stream health, as well as to understand the controls on temporal variability in these parameters.
Analysis of water and nitrogen use in New Haven
The sustainability of urban ecosystems is increasingly in question, as cities grow in population while per capita resource consumption continues to increase. Two key resources for urban areas are water and nitrogen; both of these present both scarcity issues and waste disposal issues. Together with Sheila Olmstead, I am creating a water and nitrogen budget for the city of New Haven, in order to assess the flows of these materials into and out of the city.
