Think of it as a surf-and-turf solution to agriculture runoff. Rivers and waterways across the country are carrying high loads of nitrogen, much of which originates as fertilizer and livestock waste from farms upstream. A growing amount of research, including a new study published in the journal Aquatic Geochemistry, suggests the most promising solution to that pollution is oysters.
The new study, conducted by the National Oceanic and Atmospheric Administration and the U.S. Geological Survey, looked at the Potomac River in particular. The research suggests that if shellfish populated 40 percent of the riverbed, the estuary could be completely rid of nitrogen pollution. Because a full oyster takeover of the brackish waters where the Potomac flows into the Chesapeake Bay is highly unlikely, the authors offer this middle-ground proposal too: Covering just 15 to 20 percent of the river’s bottom with oysters, which filter the water as they feed, could pull nearly half of the excess nutrients, such as nitrogen and phosphorus, out of the water.
While shellfish and ag runoff are both mainstays of the Chesapeake Bay, filtering polluted waterways via oysters isn’t a solution that’s limited to the coast of Maryland and Virginia. Rebuilding wild oyster beds and farming oysters is a viable solution to water pollution across the country. It has even been suggested that the Gowanus Canal, the Brooklyn creek that’s so toxic, new forms of pathogens are developing there, could benefit from an oyster bed.
Which begs the question: Why aren’t we introducing oysters and other shellfish to all estuaries? Not only could they help reverse years and years of excess ag runoff around the country, but the oysters from cleaner waters are good to eat too—but don't expect to be slurping Gowanus bivalves any time soon.