Federal agencies have developed a three-year research plan aimed at answering key questions before any final decision about using a fast-growing Asian oyster in the Chesapeake.

Some of the research projects would take until the end of 2007 to complete—more than two and a half years past the time frame Maryland and Virginia have established for a decision.

But the plan, which was requested by Congressional staff members, still sets a faster pace than research outlines put forth by the Bay Program’s Scientific and Technical Advisory Committee and by the National Research Council, which called for at least five years of study.

“It’s definitely a big compromise,“ said Jamie King, of the National Oceanic and Atmospheric Administration’s Chesapeake Bay Office who developed the plan in consultation with the EPA, the U.S. Fish and Wildlife Service, and scientists.

The federal agencies have long urged more study before any decision is made, but the plan was their first effort to set research priorities for Crassostrea ariakensis.

The fast-growing oyster, a native of Asia, has created a huge amount of interest among watermen and the seafood industry because tests with sterile oysters have shown that it grows fast in the Bay, resists diseases that have devastated the native oyster population, and performs well with consumers in taste tests.

That spurred the states of Maryland and Virginia last year to propose introducing a breeding population of the oysters in the Bay. The states, along with federal agencies, have begun the development of an Environmental Impact Statement that is supposed to result in a decision by next summer.

Besides reviving the beleaguered oyster industry, proponents say an introduced population of oysters, which would filter algae and sediment from the water as they feed, could help Bay cleanup efforts.

“The Bay is at risk,” Pete Jensen, associate deputy secretary of the Maryland Department of Natural Resources, told a recent Bay meeting of senior state and federal agency officials. “To do nothing is not an option.”

But the states’ timeframe, which calls for a decision next year, has been controversial. A study conducted for the Bay Program by the National Academy of Science’s National Research Council, an independent scientific body, suggested it could take six to seven years to determine whether introducing the oyster would harm or help the Bay and the seafood industry.

A report earlier this year by the Bay Program’s Scientific and Technical Advisory Committee, written by scientists from the region and around the nation, outlined a five-year research agenda that they said should be carried out before deciding whether to introduce a foreign oyster.

Although the oyster performed well in initial tests, relatively little is known about its life history, as C. ariakensis is not widely used for commercial production. That lack of information makes it hard to predict how the species would behave in the Bay.

“We don’t even know what ‘ariakensis’ is,” King said. “The taxonomy of the species is in question.” Recent NOAA-funded research by geneticists at Rutgers University has revealed that the species commonly referred to as C. ariakensis appears to consist of at least two distinct species. As a result, much of the previously published research has little value until scientists can determine exactly which oyster was being studied in each paper.

Other key questions include determining whether C. ariakensis oysters will build reefs. The ones proposed for introduction were first brought to Oregon from Ariaki Bay in Japan, where they were an introduced species. But C. ariakensis has not been observed building reefs in Ariaki Bay. If it does not build reefs, it could not replace the complex reef habitats once provided by native oysters.

C. ariakensis has turned out to be highly susceptible to a parasite, Bonamia, which was unexpectedly discovered in North Carolina last year, killing thousands of sterile C. ariakensis oysters that were being used in experiments to test the species’ usefulness in aquaculture. Studies are under way to determine whether the disease could spread to the Chesapeake if the nonnative species were introduced.

The shells of C. ariakensis are thinner than those of the native C. virginica, and some scientists believe it will be more vulnerable to predators such as crabs, and more difficult to harvest.

Other concerns focus on whether the foreign species would compete with native oysters for habitat. Limited laboratory tests suggest that very young C. virginica outcompete young C. ariakensis for space. But no one knows what would happen in the wild, or how the two species would interact during later life stages.

The Maryland Department of Natural Resources is funding more than $1 million in research to begin answering those questions, but many scientists have said it will take years to understand how the foreign species might impact the Chesapeake if it were introduced.

“The real concern for me, in terms of this time line, is that some of these projects will not bear fruit until the second or third year,” King said. For instance, studying how C. virginica and C. ariakensis oysters interact at different ages requires several years of observations.

NOAA began funding some limited research last year, and was given another $2 million from Congress for research this year. That money was expected to be awarded for 13 research projects by the end of September.

The research plan put forth by the federal agencies would require $2 million in each of the next two years to complete.

Jensen said he thought enough information would be available by next year to answer broad “threshold” questions about whether the oyster is likely to have any harmful impacts on the Bay.

If serious questions arise, he said, a decision could be postponed. “We will not proceed with an introduction of a nonnative oyster if unacceptable risks are identified,” he said. Jensen said the state wanted to avoid an “open-ended” research program.

It’s unclear who would make the decision next year. State officials have said it’s their call, but EPA officials have said they may have regulatory authority under the Clean Water Act.

Regardless, Virginia Secretary of Natural Resources Tayloe Murphy recently expressed doubt that a scientifically valid decision to introduce the nonnative oysters could be made next year.

The research needs identified by scientists “is going to make it very difficult to meet the timetable that has been laid out for the Environmental Impact Statement,” Murphy told the Chesapeake Bay Commission, which represents state legislatures, in September.

Murphy said he supported continued experiments with sterile oysters to gain more information. “I don’t believe you will get the answers without having oysters in the water,” he said.

The Virginia Seafood Council has funded experiments using sterile C. ariakensis oysters to determine whether they can be economically grown in aquaculture. Last fall, about a million oyster were distributed among aquaculture growers, and officials hope to gain both economic and biological data from the study.

Because of the divergence of views about how much research is needed to make a decision, Charlie Stek, an aide to Sen. Paul Sarbanes, D-MD, suggested that the scientists on the National Research Council panel be reconvened to review the research plans and determine how much study will be needed to make a credible decision.

“We want to make sure that you have a defensible and thorough Environmental Impact Statement at the end of this process,” Stek said.

He said members of Congress were trying to secure additional research funding for next year.