Cadmium
From Coastal Wiki
Cadmium is a heavy metal. The main anthropogenic sources are copper and nickel smelting, and fuel combustion. As such, it mostly enters the marine ecosystem through atmospheric loading and riverine discharges.[1]
Like other heavy metals, cadlium does not have biomagnifying properties. Higher trofic levels accumulate low amounts of cadmium and are able to deal with them efficiently with metallothioneins. Mollusks contain large amounts of cadmium and seam to accumulate them.[2]