The invertebrate organisms attached to the plastic panels are Styela , an introduced species of ascidian related to Botrylloides . Luckily, no one yet has seen it in the Chesapeake. Years ago the MSX disease appeared in Chesapeake waters. That disaster has all but paralyzed plans to jump-start a new oyster industry in Chesapeake waters by introducing the similar Pacific oyster. Dr. Osman says that even if the Pacific oyster were MSX-free and immune to the disease, to be on the safe side, the seed oysters would have to be rigorously cleaned of attached organisms and quarantined.
Nobody is yet confident that is possible.
Scientists are also uncertain of what other unknown diseases could come into the Bay with the introduced oysters. They also wonder whether the oysters would grow big enough to be marketable. Osman says Chesapeake Bay waters are most vulnerable to alien species riding here aboard ships from Mediterranean and other European ports where harbor water is similar. Odds against this match-up may save the bay from many alien invaders. The difference in salinity between harbor and ocean water will likely kill most of the hitchhiking species.