We are researching the factors that drive bacterial pollution in estuarine waters (e.g., climate variability, wastewater management, and agricultural practices), and their potential as indicators of estuarine condition. Our research will support management of coastal resources through better understanding of how human practices and climate changes affect coastal condition in the Chesapeake Bay, and how indicators of bacterial pollution relate to the presence of pathogen groups.
Why We Care
When deciding to restrict use of a natural resource, such as a shellfish bed or recreational beach, coastal managers often rely on assessment tools that provide limited information.
Our research directly addresses information needs of coastal resource managers and partners in the Chesapeake Bay. For example, the Maryland Department of the Environment may refine shellfish bed closure decisions based on our findings about climate drivers. Our findings may also be useful to state and local managers evaluating the effectiveness of best management strategies and communicating the drivers and variability of coastal pollution. We also hope to improve our understanding of the relationships between pathogens and microbial communities associated with bacterial pollution indicators.
What We Did
We quantified the relationship between inter-annual precipitation and air temperature patterns and the densities of fecal indicator bacteria in shellfish harvest waters in Maryland’s portion of the Chesapeake Bay using 34 years of data (1979–2013).
We partnered with the Maryland Department of the Interior/ Science Services Administration, the University of Maryland’s Center for Environmental Studies, and Oregon State University.
What We Found
Annual and seasonal precipitation totals had a strong positive relationship with average fecal coliform levels in shellfish harvest waters. Fecal coliform levels were also significantly and negatively related to average annual air temperature. Continental-scale sea level pressure (SLP) analysis revealed an atmospheric pattern that influences both extratropical and tropical storm tracks and very high fecal coliform years, while regional precipitation was found to be significantly correlated with the Atlantic Multi-decadal Oscillation and the Pacific North American Pattern. These findings indicate that management of shellfish harvest waters should account for changes in climate conditions and that SLP patterns may be particularly important for predicting years with extremely high levels of fecal coliforms.
We will publish a paper on the microbial community associated with bacterial pollution indicators at a shellfish harvest station in the Chesapeake Bay.