The state governments of Maryland and Virginia, along with the Army Corps of Engineers, announced yesterday that Asian oysters will not be allowed in the Chesapeake bay. The decision capped a five-year study on the nonnative oyster to assess its potential to replace the rapidly diminishing native Eastern oyster, Crassostrea virginica.
The decision ultimately came down to the Army Corps of engineers, since Virginia officials supported the introduction and Maryland officials opposed it. For now, at least, the states and federal government will put their money on resuscitating populations of native oysters, which have dwindled to as little as 1 percent of their peak populations because of disease and overfishing. So far these attempts have had limited success, and future efforts could cost as much as $50 million per year, ten times more than was invested in years past.
The presence of oysters in the bay has more far-reaching importance than just the fisheries industry: the bay needs a core filter-feeder to clean its increasingly polluted waters. The five-year study was inconclusive about whether the Asian oyster could invade and wreak havoc on the system — much like freshwater zebra mussels have in the Great Lakes — instead of settling into the native oysters’ niche and providing the much-needed ecosystem service. The decision, then, was not to risk it.