Relationships Between Concentrations of Metals in Sediment and Two Species of Freshwater Mussels in the Ottawa River

Abstract

Abstract This study examined the relationships between concentrations of metals in sediment and freshwater mussels from the Ottawa River to determine whether mussels could provide useful Information on the bioavailability of sediment-associated metals. Sediment and two species of mussels, Elliptio complanata and Lampsilis radiata (F. Unionidae), were collected from several sites on the river and analyzed for residues of nine metals. Significant positive correlations between concentrations in mussels and sediment were observed for only four metals (Cd, Cr, As, Se), even though the readily extractable or “bioavailable” fraction of the total load in sediment was compared for all metals except As, Se and Hg. Lack of correlation for other metals may have been due to a narrow range of exposure concentrations tested or to the regulatory capabilities of the mussels themselves. Interspecific differences in bioaccumulation were observed for As, Cr, Cu, Ni and Zn. Interpretation of data from mussel monitoring programs requires knowledge of the complex processes influencing bioaccumulation.