A reef seeded with oysters by the state of Maryland — about 130 oysters per-square-meter — removed 20 times more nitrogen pollution from stuff such as home lawn and farm fertilizer in one year than a nearby site that had not been seeded, according to a recently released study.
Lisa Kellogg, a researcher for the Virginia Institute of Marine Science who led the four-year study, told the Washington Post that oyster reefs could potentially remove nearly half the nitrogen pollution from the Choptank River on Maryland’s Eastern Shore. A wider restoration could help clean Chesapeake Bay, where the Choptank and other major rivers drain.
Man-made nitrogen pollution is part of a one-two punch that creates oxygen-depleted dead zones that have plagued the bay. At one time, when oyster reefs were so mountainous and plentiful that European explorers complained about navigating around them, Chesapeake Bay was crystal clear.