 Mussel Watch monitors the concentration of contaminants in bivalves (mussels and oysters) and sediments in the coastal waters of the U.S., including the Great Lakes, to monitor bivalve health and by extension the health of their local and regional environment.Mussel Watch consults with experts to determine appropriate contaminants to monitor; these include dichlorodiphenyltrichloroethane (DDT), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs).As of 2008, Mussel Watch monitors approximately 140 analytes.