Antibiotic resistance in microbial communities in aquatic systems

Recently there has been concern over the increasing concentration of antibiotics in streams and the prevalence of antibiotic resistance amongst pathogenic microorganisms. Due to the nature of resistance mechanisms, it is important to quantify potential reservoirs of resistance. My lab is currently quantifying antibiotic resistance in a variety of stream microbial communities.

Role of photochemical and microbial processes on the degradation of Phragmites-derived and Spartina-derived organic matter in Delaware Bay salt marshes

Typically dominated by Spartina alterniflora, the marshes of the Mid-Atlantic are being altered by the invasion of Phragmites australis (foreground of picture). Salt marshes are typically heterotrophic systems with Spartina playing major role in fueling the microbial food web. Understanding how the alteration from Spartina-dominated to Phragmites-dominated marshes affects secondary production is important for understanding how the whole marsh ecosystem is functioning. This work is funded through the New Jersey Sea Grant Consortium Marsh Ecology Research Program.

Restoration of stream ecosystems through removal of small dams

In recent years, concern over degradation of aquatic resources, issues of liability, and maintenance costs, has led to the removal of several small dams around the United States. However, few studies have been conducted that document the scope and magnitude of the ecological changes associated with dam removal. Along with colleagues at the Patrick Center for Environmental Research, the University of Delaware, and the Delaware Riverkeeper Network, I have been studying the ecological effects of removing a small dam on the Manatawny Creek ecosystem in Pennsylvania. For more information please see http://www.acnatsci.org/research/pcer/manatawny.html.

Annual leaf litter input in a Pennsylvania stream

Organic matter dynamics in stream systems with small dams

In order to better predict the ecological effects of dam removal, it is important to have an understanding of the ecological effects of the dam while it is in place. A key process in stream ecosystems is the decomposition of organic matter. My research has been focusing on stream systems with small impoundments to determine if there are significant differences in the processing of organic matter by biological communities due to the presence of a dam.