Maryland and Virginia have agreed for the first time to introduce 1 million nonnative oysters to open waters of the Chesapeake Bay and the Atlantic Ocean, setting aside long-standing fears of unleashing unknown environmental consequences in the mid-Atlantic region.

The decision is one measure of how increasingly desperate the states are to find a surrogate for the native Chesapeake Crassostrea virginica, which once was the most plentiful oyster in the world but has been devastated by disease and over-harvesting.

In moving ahead with the plan, the states are ignoring the opposition of two federal agencies and preempting the advice of the National Academy of Sciences, which they solicited last year and is expected this summer.

Yesterday, the Virginia Marine Resources Commission approved a proposal by the Virginia Seafood Council to plant 1 million Asian Crassostrea ariakensis oysters in eight locations in the bay and two sites in the Atlantic. The oysters will be bred to be sterile, but scientists acknowledge that some of the oysters might be able to reproduce.

How that could affect the native populations of oysters and the aquatic food chain is unclear. For that reason, the states had asked the academy to study the potential impact of introducing a nonnative oyster even as the U.S. Fish and Wildlife Service and National Oceanic and Atmospheric Administration spoke out against it.

Maryland, which under the previous Democratic administration had opposed the introduction of an alien oyster, has apparently warmed to the idea of testing an oyster that could revive a moribund industry and help clean the bay of pollution.

In a letter to Virginia officials, the director of shellfish programs for the Maryland Department of Natural Resources urged changes in the Virginia plan to limit the amount of time the oysters are in the water and increase tracking of the animals in the water and when they are removed. He did not object to the project going forward before the academy issued its recommendation on the risks of introducing the oyster.

"They have another season of frustrating [restoration] activities under their belt, and they have another season of an oyster fishery behind them, and neither is getting better," said Ann Swanson, executive director of the Chesapeake Bay Commission. The commission sought the academy's opinion on the proposal and helped gather $300,000 from both states and various federal agencies to fund a study.

The results of that study are expected in August, possibly months after Virginia plans to begin planting mesh bags of Asian oysters in its waters of the bay.

Frances Porter, executive director of the Virginia Seafood Council, said that if the experiment is successful, it could mean a culture shift for the oyster industry.

Maryland and Virginia oyster populations have crashed and harvests plummeted because of disease in recent years. The decline has been so drastic that many Maryland watermen have gotten out of oystering. In Virginia, 99 percent of the oysters processed come from out of state.

The push for introduction of a new, nonnative oyster has been stronger in Virginia, where seafood industry officials have lobbied relentlessly for help in maintaining their livelihoods. University of Maryland researchers have been rebuffed from testing nonnative oysters in Maryland waters.

This year, however, Maryland lawmakers are pushing legislation that would allow researchers to test the Asian oyster, which grows faster and appears to resist the two diseases that eventually kill most Chesapeake oysters.

Don Boesch, president of the University of Maryland Center for Environmental Science, said the entrance of the new Republican administration led by Gov. Robert L. Ehrlich Jr. has led to new hope among scientists, seafood industry officials and watermen that the state will consider new research trials in the open waters of the Chesapeake. The previous administration rejected such trials.

"The watermen and other interests have been discussing this with people in the new administration even before they were in office," said Boesch, whose scientists grow most of the oysters planted in the Maryland waters of the Chesapeake today. "I think they're sensitive to concerns about allegations that [Maryland] was going too slowly on this."

However, a spokesman for the National Academy of Sciences expressed surprise yesterday that Virginia planned to introduce Asian oysters before the academy study was completed.

"We really were expecting they'd use our report to help them to make their decision," said Bill Skane, a spokesman for the academy. On Friday, the academy sent a letter to the Virginia Marine Resources Commission, expressing concern that if it approved the seafood council's plan, the Asian oyster trial might as well be considered a "first-time introduction" as a nonnative species.

"The letter was just to point out that the work they asked us to do hasn't been completed yet," Skane said. "There was concern this process might be going too quickly."

Asian oysters are going to be placed in the Chesapeake Bay and Atlantic Ocean.