Interactions Between Eutrophication and Contaminants. II. Mobilization and Bioaccumulation of Hg and Cd from Marine Sediments

The bioaccumulation of contaminants in benthic invertebrates is strongly affected by the availability of labile organic matter and oxygen from the bottom water. A two-factor microcosm experiment was developed to evaluate this assumption. Researchers maintained three species of sediment-dwelling organisms in sediments containing elevated concentrations of super(203)Hg and super(109)Cd. The organisms used in these tests included Abra alba, Nereis diversicolor, and Amphiora filiformis. In addition, samples of blue mussels (Mytilus edulis) were maintained downstream from the test containers in separate vessels. The waters flowing through the aquaria were distinguished by two levels of organic carbon and two levels of oxygen. Monitoring of gamma emission values for the two isotopes was then conducted for samples of sediments, porewater, and biota.