National Status And Trends, Mussel Watch Program : A 2022 Assessment of Trace Metals in Dreissenid Mussels in the Great Lakes Basin

In 2022, the National Oceanic and Atmospheric Administration (NOAA) Mussel Watch Program (MWP) conducted an assessment of the presence, distribution, and concentrations of trace metals in mussels (Dreissena polymorpha and Dreissena rostriformis bugensis, collectively referred to as dreissenid mussels) from the Great Lakes Basin. The national MWP utilizes a sentinel-based monitoring approach by collecting and analyzing bivalves as surrogates for coastal water pollution. Mussels and oysters are sessile organisms that filter and accumulate particles from water; therefore, measuring contaminant levels in their tissue is a good indicator of local chemical contamination. Dreissenid mussel tissue samples from 66 monitoring sites across the Great Lakes Basin from Wisconsin to New York were analyzed in this study. Samples were analyzed for 14 trace metals including aluminum (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), nickel (Ni), selenium (Se), silver (Ag), tin (Sn), and zinc (Zn).