Date Awarded


Document Type


Degree Name

Master of Science (M.Sc.)


Virginia Institute of Marine Science


Fecal contamination in estuaries has become an increasing concern worldwide. The use of wetlands for wastewater treatment has expanded due to their natural ability to improve water quality by removing suspended sediments, nutrients, and fecal bacteria. In general, most of the removal occurs through deposition and accumulation in the wetland substrate. This would suggest that wetlands are effective filters for fecal coliform transported from terrestrial environments to surface waters. It has also been hypothesized, however, that wetlands may be an intermittent source of fecal coliform in tidal systems as a result of wildlife deposition and /or accumulation from terrestrial sources. To investigate the role of tidal wetlands in fecal coliform loadings from small estuarine systems, this project examines the difference between monitoring data and modeling data for shellfish growing areas in Virginia. Results suggest that models should treat tidal wetlands as discrete components of contributing watersheds, rather than assuming they can be grouped with forested land areas. Tidal wetlands’ role in fecal coliform transport could be embodied through the net sediment transport between tidal wetland and adjacent coastal water. When the tidal wetland substrate is resuspended, what happens to the water quality? Do tidal wetlands contribute to and how they contribute to the high amount of fecal coliform (FC) in shellfish harvesting zone? To address these questions, Loading Simulation Program C++ (LSPC) and a hydrodynamic model - Tidal Prism Water Quality Model were used to simulate fecal coliform transport through the watershed (including wetlands) and coastal waters with the support of the project of Development of Shellfish TMDLs for Virginia. The error analysis, that is the discrepancy between the model prediction and observation data, will then be used to explore the sinks and/or sources of fecal pollution in tidal marshes. Seasonal variation of fecal coliform concentrations in shellfish growing water and model sensitivity tests will be analyzed and discussed surrounding this issue.



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