Fate of Mercury Contaminants in Narragansett Bay, Rhode Island (2006 - Present)

Investigator:  David Taylor, Roger Williams University
Mentor:  Warren Prell, Brown University

Abstract:  Mercury (Hg) is a toxic environmental contaminant affecting human health, and exposure occurs mainly through dietary uptake of contaminated fish. To minimize Hg exposure, public health officials affiliated with the U.S. Food and Drug Administration, U.S. Environmental Protection Agency, and state agencies issue consumption advisories to inform citizens of the possible health risks associated with eating fish. While consumption advisories have been developed on a site-specific basis for fish inhabiting freshwater systems, advisories regarding the consumption of saltwater species lack geographic specificity. To this end, national consumption advisories for marine fish are possibly ill-advised and ineffective because they do not account for small-scale spatial variations in Hg contamination. Hg contaminants in local coastal fisheries, however, may be predictable if causative factors are taken into account, e.g., spatial variation in Hg pollution from locally- and distantly-derived sources, dietary differences among fish species, and residence time within water bodies of interest. Thus, research focusing on marine ecology and environmental chemistry is needed to support the development of models describing relationships between bioavailable Hg and local fish contamination. This investigation will focus on Narragansett Bay, Rhode Island, where local fisheries are important dietary and commercial resources for denizens of the state.  Rhode Island land use/watershed characteristics and potential point sources of Hg will be correlated with measured values of Hg from site-specific collections of sediment and certain marine fish and invertebrate species. These data will be used within the framework of a geographic information system to create predictive models and analyze spatial relationships between Rhode Island land use and watershed characteristics, Hg pollution, and contamination in the marine food web. These empirical models will be evaluated and refined to include spatial and mechanistic factors underlying Hg bioaccumulation in marine fish, as determined by environmental Hg levels and food web analyses. Such models provide the necessary link between environmental regulations and their efficacy in minimizing dietary fish Hg contamination in humans.