Behold the tiny oyster.
No, not on the half-shell, with a squirt of lemon, but in its watery habitat, the Choptank River. Out there on a reef with many other oysters, the bivalve is awesome, a janitor that helps remove pollution with incredible efficiency.
A reef seeded with oysters by the state of Maryland - about 130 oysters per square meter - removed 20 times as much nitrogen pollution from stuff such as home lawn and farm fertilizer in one year as a nearby site that had not been seeded, according to a recently released study.
The upshot, said Lisa Kellogg, a researcher for the Virginia Institute of Marine Science who led the four-year study, is that oyster reefs could potentially remove nearly half of nitrogen pollution from that one river on Maryland's Eastern Shore "if you took all the areas suitable for restoration and restored them." A wider restoration could help clean the Chesapeake Bay, where the Choptank and other major rivers drain.
It is a huge deal, Kellogg said. Man-made nitrogen pollution is part of a one-two punch that creates oxygen-depleted dead zones that have bedeviled the bay. At one time, when oyster reefs were so mountainous and plentiful that European explorers complained about navigating around them, the Chesapeake was crystal clear.
Oyster reefs are more than just the rocks of ages. They are the ultimate mixed-use development, inhabited by more than 24,500 marine animals that are not oysters - mussels, clams and sea squirts, to name a few - that also filter nitrogen.
Excessive harvesting of oysters, combined with massive farm and urban pollution, depleted the bivalves, denuded reefs and clouded the water by the 1980s. About that time, two diseases, Dermo and MSX, came out of nowhere to decimate the stock of oysters in Maryland and Virginia.