INTERACTIONS BETWEEN METALS AND MICROBIAL COMMUNITIES IN NEW-BEDFORD HARBOR, MASSACHUSETTS

The fate of toxic metals in marine sediments depends on a combination of the physical, chemical, and biologic conditions encountered in any given environment. These conditions may vary dramatically, both spatia lly and temporally, in response to factors ranging from seasonal chang es and storm events to human activities such as dredging or remediatio n efforts. This paper describes a program designed to evaluate the int errelationships between the microbial community and pollutants in the New Bedford Harbor, Massachusetts, area, a U.S. Environmental Protecti on Agency designated Superfund site. Research has focused on establish ing distributional relationships between contaminant metals, fluxes of metals between sediments and the overlying water, changes in microbia l diversity in response to metals, and potential use of the microbial community as a biomarker of contaminant availability. This research ha s shown that a significant flux of metals to the water column is media ted by benthic biologic activity, and that microbial communities may b e a responsive marker of contaminant stress. A combination of biogeoch emical studies and the use of molecular tools can be used to improve o ur understanding of the fate and effect of heavy metals released to aq uatic systems.