He says evidence supports both possibilities, perhaps operating together. Once we find where these toxic metals are coming from we'll be able to and contaminating our seafood. Finally, as the Patuxent River runs into the Chesapeake, the concentrations of toxic metals go down again, the river water diluted by the waters from the Atlantic. Relative amounts of toxic trace metals in Patuxent River oysters compared with all U.S. oysters. Toxic metals are not the only major pollutants in the Patuxent, Dr. Riedel says.
Organic pollution continues as a persistent problem.
Excess nutrients are well-known pollution villains because they cause population explosions of life at the bottom of the food chain, using up so much oxygen dissolved in the water that there is not enough for fish and other higher forms of water life. This offer is restricted to U.S. postal addresses only.