CONTAMINANT AND NUTRIENT ELEMENT LEVELS IN SOFT-TISSUES OF ZEBRA AND QUAGGA MUSSELS FROM WATERS OF SOUTHERN LAKE-ONTARIO

The objective of this study was to compare concentrations of toxic and nutrient elements in soft tissues of two dreissenid mussels, Dreissena polymorpha and a new dreissenid species given the working name of ''quagga'', collected from the New York waters of Lake ontario. In general, elemental concentrations were similar between the two mussel types. The only exceptions were concentrations of Cr, Mo and Zn which were significantly (p < 0.05) higher in zebra mussels compared to quagga and V which was significantly (p < 0.05) higher in quaggas. There was little or no relationship between shell size and contaminant concentration for both mussel types. Only Cd and Mn exhibited significant differences (t-test, p < 0.05) between large and small shell size categories and this Was limited only to quaggas. Elemental concentrations of Cu, Cd, K, Na, Ni and Zn in mussel soft tissues increased (p < 0.05) with Lake Ontario water depth. Elevated levels of Cd, Ni, Pb and Se were observed in both quagga and zebra mussels at all sites and could pose a contaminant risk to organisms such as waterfowl that heavily utilize mussels for food.