Saying the potential for an oyster native to southeast Asia is “limitless” in the Chesapeake, the Virginia Seafood Council has proposed placing 1 million of the foreign species in the Bay, its tributaries and nearby coastal waters this summer.
The proposal, submitted to the Virginia Marine Resources Commission in April, represents a 16-fold increase from last year in the number of the sterilized nonnative Crassostrea ariakensis oysters that would be used in aquaculture.
The fast-growing, disease-tolerant oysters would be distributed among 39 people, up from 13 who participated in experiments last year. Even more people were interested, but they did not apply in time, said Frances Porter, director of the council, a trade association representing seafood processors and watermen.
“Excitement is high among the people who have grown these oysters and have faith in this project,” Porter said. “It is everything we are looking for: disease-resistant, plump, tasty.”
The Commission will review the request and is scheduled to make a decision after a public hearing at its June 18 meeting.
The proposal is likely to receive heavy criticism, especially from federal agencies, many of which approved a statement late last year strongly opposing the use of ariakensis, also known as the Suminoe oyster, in the Bay because too little is known about its potential impact on the Bay ecosystem.
The U.S. Fish and Wildlife Service in April sent a letter to various states and federal agencies calling for a moratorium on any further use of ariakensis in the Bay until a review of risks and benefits is completed by the National Academy of Sciences.
In the meantime, the Service urged state and federal agencies to review their regulatory authority and “exercise appropriate responsibility as it pertains to this important issue.”
The Academy recently agreed to launch a yearlong review of the ariakensis issue, looking at the environmental and economic consequences of using — and not using — the nonnative oyster. The study will not only look at using sterile oysters in aquaculture, but also the pros and cons of establishing a reproductive ariakensis population in the Bay.
Maryland officials, who have strongly opposed any open-water work with foreign oysters in the past, were still reviewing the council’s proposal. “We certainly don’t want to do anything premature knowing that the National Academy of Sciences will be reviewing the whole issue,” said Eric Schwaab, fisheries director for the Maryland Department of Natural Resources.
Porter said the council chose not to wait for the results of the academy’s study because it expects the final report to endorse ariakensis aquaculture. “There was a strong feeling that nothing is going to come out of this that would stop the work,” she said.
The council’s request reflects a surge of interest in ariakensis among watermen and the seafood industry in both Virginia and Maryland. Two diseases, MSX and Dermo, have devastated the native oyster, Crassostrea virginica, sending Bay harvests to record lows.
The diseases have been particularly devastating in Virginia, where they thrive in its high-salinity water. Harvests which totaled more than 1 million bushels annually in the state as recently as 1980 now amount to less than 5,000 bushels a year.
Because of the bleak situation, the state’s General Assembly in 1995 directed the Virginia Institute of Marine Science to explore the potential of using nonnative species. Initially, work with other species failed to produce promising results, but when scientists began working with ariakensis — a species not widely used in aquaculture anywhere else — they found it appeared to thrive in the Bay.
Tests supported by the council using 6,000 ariakensis oysters two years ago showed the foreign species grew far faster than the native oyster, reaching market size in 9-12 months, and did not succumb to disease. In some places, all the native oysters died in the side-by-side experiments.
Market studies with consumers suggested little difference in taste between the native and nonnative species.
Last year, 60,000 ariakensis oysters were grown, and while final results are not in, Porter said anecdotal reports suggested “excellent” results.
“There were almost no deaths, if any,” she said. “Some of them grew to market size in less than 7 months.”
But the prospect for expanded use in the Bay has alarmed others.
Because the technology to render oysters sterile is not 100 percent effective, a major worry about ramped-up use of ariakensis is that it could lead to an accidental introduction of a breeding population.
Ariakensis is poorly studied in its native habitat, and scientists cannot predict what impact it could have in the Bay. Some fear it may compete with native oysters — further hurting the population — as well as other bottom-dwelling species. Another worry is that the oyster could introduce a new aquatic virus into the Bay.
The Bay Program has a policy generally opposed to the use of nonnative species in the Chesapeake. Under the policy, a special “Ad Hoc Panel” is formed when a new, or expanded, use of a nonnative species is proposed. A recently formed panel is reviewing the issue, and is expected to make recommendations by June 11.
“The reason we have a Bay Program policy on first-time introductions, and the reason we have an ad-hoc review process, is that the history of nonnative introductions is bad, and this could be bad for the Bay,” said Mike Fritz, living resources coordinator with the EPA’s Bay Program Office.
One of the largest concerns voiced about the council’s proposal is the technique used to render the oysters sterile. It would rely on chemically treating oyster larvae with a naturally produced antibiotic derived from fungi which cause the oysters to become “triploids” — having three sets of genes, rather than the normal two, therefore rendering them sterile.
But chemically induced triploidy is not as effective as another method, in which tetraploid oysters (oysters with four sets of genes) are bred with diploids (oysters with two sets of genes) to create triploids this year.
That technique is not being used because the process of creating tetraploid oysters has proven difficult, and VIMS scientists — who would produce the oysters for the Council’s test — have not been able to make enough to breed triploids.
As many as 1 percent of the chemically treated oysters may still be capable of reproduction — or 10,000 of the 1 million proposed deployment.
“We don’t want to see a de facto introduction in the name of doing some industrial trials,” said Bill Goldsborough, senior scientist with the Chesapeake Bay Foundation. “The proposal as it is now configured is not something that we could support.”
But, he said, CBF officials were hoping to meet soon with the seafood council representatives to discuss whether the proposal could be modified.
“We are fully supportive of some bona fide trials,” Goldsborough added.
Porter said the risk of reproduction was low, noting that the oysters would be distributed among 39 sites, so there would be few reproductive-capable ariakensis oysters at any location. Further, the council’s plan calls for removing the oysters next May, when it is thought conditions would still be too cool for spawning.
Others, though, contend that the exact spawning conditions for ariakensis are unknown. And, spreading an average of 250 diploids per batch among a wide range of growing conditions, as the proposal suggests, would increase the likelihood that the oysters would encounter suitable spawning temperatures and salinities.
All oysters used in the project would be placed in bags to prevent them from getting loose into the Bay. In addition, the council’s proposal said all participants will develop emergency plans to prevent the oysters from being released in the event of hurricanes or other severe weather events.
Although 1 million oysters represents a huge increase over last year’s experiment, the council said it amounts to only about 3,300 bushels — slightly smaller than the annual wild harvest of native oysters in Virginia. It is also fewer than the number grown by “oyster gardeners” who hang bags of native oysters off docks, it said.
Porter said the biggest danger is not continuing to work with ariakensis, and continuing to allow the oyster resource to slip away. “What is the risk?” she asked. “That we will have more oysters in the Bay?
“I hear all this talk about the risk, but I hear very little talk about the benefits — the benefits of a restored industry, and the benefits of having this little animal help filter the Bay.”
She said the lack of oysters threatens the health of the Bay — oysters historically were a critical water filterer — the seafood industry, the watermen who once harvested oysters and the communities they support.
Right now, only 1 percent of the oysters processed by the seafood industry in Virginia originate from the state’s waters, and other sources of oysters — including the Gulf Coast, Northeast states and Maryland — are increasingly unreliable, according to the council’s proposal.
Efforts to restore native oysters in the state have not had promising results, the council said, and aquaculture with the native species is problematic because even specially bred, disease-tolerant strains usually die before reaching market size. “The fact that there are only a few relatively small commercial farms for C. virginica is itself attestation to its commercial inviability,” the council said.
By contrast, with more work to domesticate and genetically improve ariakensis for aquaculture, the council said growers can expect “significant gains over the already exceptional performance of C. ariakensis.”
As a result, the proposal argued it is time to try a “more creative, even aggressive” effort to revitalize the oyster industry. It envisions an industry built — at least initially — upon ariakensis reared in aquaculture, and potentially with a wild population placed in the Bay in the future.
Unless action is taken soon, Porter said, the state’s historic oyster industry will be gone altogether. “Our vision is in a few years to have 100 million oysters in the Bay,” Porter said. “Our goal is to restore an industry; to have a marketable, viable industry as quickly as is safe.”
Jack Travelstead, fisheries director for the Virginia Marine Resources Commission, said the commission staff would review the council’s request both for its environmental impact, and for the overall quality of the proposal, before making a recommendation.
“It’s going to be rigorously reviewed by the staff here, by the VIMS staff, and by the Bay Program’s Ad Hoc Panel,” he said. In addition, he expected federal agencies to weigh in with comments. “All that information will go to the commission.”
Besides needing approval from the VMRC, the Army Corps of Engineers has also indicated that it must issue a permit before the project could go ahead.