NEWPORT NEWS, Va. -- Virginia Marine Resources Commission chief William A. Pruitt has rescinded a commission decision allowing scientists to place Japanese oysters in the York River to see whether they resist MSX, a disease that has killed countless oysters in the Chesapeake Bay.
Mr. Pruitt's ruling was prompted by a recommendation by Virginia Institute of Marine Science Director Dennis L. Taylor to keep the foreign oysters out of the bay until scientists can guarantee the oysters can't successfully reproduce. The recommendation in a June 16 letter to Mr. Pruitt was made public yesterday.
Maryland officials had hinted that they would seek a court injunction to stop scientists from placing the foreign oysters in the bay.
"We welcome Dennis Taylor's caution," Pete Jensen, chief of the Maryland Department of Natural Resources' Fisheries Division, said yesterday.
Nature had already derailed the York River experiment: Most of the Japanese oysters destined for the river died in June in their tank at a Rutgers University research laboratory near Cape May, Even if they had lived, Mr. Pruitt's decision would postpone the experiment until at least next year.
Talk of placing Japanese oysters in the bay has triggered both hope and fear: hope that the hardy species will resist oyster-killing diseases and rejuvenate the bay's oyster population, which is less than 1 percent of what it was 100 years ago; and fear that it will bring with it disease-spreading parasites that will kill other fish and shellfish.
Mr. Jensen, the Maryland fisheries official, said scientists can determine whether Japanese oysters will resist MSX without placing them in open waters.
Mr. Taylor based his recommendation on research by a Rutgers University oyster scientist who has been working to create sterile oysters.
Standish Allen, the Rutgers scientist, has said that he can't guarantee "100 percent sterility" in the oysters. He is out of the country and could not be reached for comment yesterday. But in an interview last month he claimed, "There's no better way to make them sterile than what I'm doing." He explained that oyster eggs hold three sets of chromosomes, one of which is usually not used and is excreted. He disrupts reproduction by bathing oysters with a special chemical, which forces them to maintain the extra set of chromosomes. With that set of chromosomes present, "you have an abnormal reproduction because you have an abnormal sperm and egg," Mr. Allen said. "It virtually ensures that a normal progeny will not be produced," he said.
The "virtually" part worries scientists like Mr. Taylor, who is also out of the country and could not be reached for comment. Mr. Taylor "wants security before moving ahead with the experiment," said Robert Byrne, head of research at VIMS.