DESPITE recent small successes, the daunting task of restoring the oyster population of the Chesapeake Bay will take many decades.
Baywide oyster harvests today are but 7 percent of 1950s highs.
Overharvesting, persistent lethal diseases, pollution and loss of reef habitat are primary causes.
One idea gaining currency, especially among hard-hit watermen, is to use a fast-growing, disease-resistant oyster from Asia to restock the bay.
Virginia, where the oyster industry has virtually disappeared, is enthusiastic about possible use of the foreign C. ariakensis species.
Maryland officials are strongly opposed, fearing the alien could overwhelm the native Chesapeake C. virginica oyster, introduce new diseases and disturb the environment of the estuary.
Laboratory-hatched, infertile Asian oysters have been grown in confined Virginia bay tributaries for two years, with encouraging results.
Taste tests show it to be equal to the native species.
There's mounting pressure to use more lab hatchlings in expanded aquaculture projects, and even for fertile, reproductive oysters to help restock the bay.
Proponents say that could relieve harvest pressures on the slowly recovering native virginica species, giving watermen an alternative income source. And it would advance the Chesapeake Bay Agreement goal of increasing oyster population tenfold by 2010. More oysters would improve the natural filtering of bay waters.
But there's good reason for strong caution before unleashing this exotic species in the bay.
Experimenting with the C. gigas oyster decades ago brought the devastating MSX disease to the bay. Other alien species have had unforeseen harmful effects on the ecology. Scientists believe the Asian oyster won't build the extensive reefs that provide vital habitat for other Chesapeake creatures.
Even confined aquaculture colonies in the bay risk the eventual accidental release of spawning foreign oysters, because the lab sterilization process is not foolproof.
Expanded research on this promising species is needed now, even as we work to restore the native Chesapeake oyster.
