Scientists say history on oyster misleading

Species' use in Oregon limited, officials are told

February 19, 2005|By Rona Kobell and Tom Pelton | Rona Kobell and Tom Pelton,SUN STAFF

Maryland Natural Resources officials often downplay the risks of a proposal to put Asian oysters in the Chesapeake Bay by pointing out that the foreign species was brought long ago to other U.S. waters without apparent harm to the environment.

"These oysters have been on the West Coast since 1960," Secretary C. Ronald Franks said this week at a hearing before a Senate committee in Annapolis.

That statement could be misleading, some scientists say.

Although the oyster, Crassostrea ariakensis, was placed in waters off the coast of Oregon in the 1960s, the species never established itself there. It did not reproduce outside research laboratories, and most of the animals died.

No ariakensis are known to remain in Oregon, said Christopher Langdon, a fisheries biologist at Oregon State University, which supervised the population. A few dozen of their descendants live in a hatchery in Washington state, he said.

"It's true to say that the species has been in the United States for four or five decades," Langdon said. "However, the culture of the species on the West Coast has been very, very limited."

This week's hearing was on legislation that seeks to stop the Ehrlich administration from introducing the species into the bay without several more years of study. Administration officials say it's imperative that the state move quickly to replace a native oyster population that has been all but wiped out by disease and over-harvesting.

Critics say the administration - which hopes to make a decision this summer - is moving too quickly. Introducing non-native species can cause irreversible harm to the environment, they say.

The frequent references by state officials to an ariakensis population on the West Coast might give some listeners a false sense of comfort, several scientists said this week.

"It overstates our understanding of the oyster, given that it never really became naturalized there," said Mark Luckenbach, an oyster ecologist at the Virginia Institute of Marine Science.

"While indeed these animals have been in the Pacific Northwest for decades, in fact, extremely little has been done with them there," Luckenbach said. "They have not actively been part of any aquaculture industry. They haven't been established in the wild. And there haven't been any ecological studies."

Franks said his department isn't trying to mislead anyone. He said he brings up the oyster's West Coast connection to allay concerns that it might bring in parasites.

"The fear which I think people have - and I think we should respect that fear - is that if you bring something new in, you can bring `hitchhikers' with it," Franks said.

Virginia experiment

He pointed out that in addition to the West Coast experiments, the Asian oyster - though a sterile strain - is being raised under supervised conditions in Virginia.

"This oyster has been on the West Coast since the 1960s and in Virginia since 1996," Franks said. "To me, there is a dramatic distinction between that and us bringing a jet over to Japan, filling it with a bunch of oysters and bringing them back over here."

Donald F. Boesch, president of the University of Maryland Center for Environmental Science, sought to clarify the state of Asian oysters on the West Coast in his testimony in Annapolis this week.

Boesch said he wanted to be sure legislators knew that the oyster is not naturalized in Oregon and doesn't exist in the wild outside Asia.

`Had to be clarified'

"I thought it had to be clarified, and that's why I brought it up," he said.

The possible West Coast misperception has been a concern for scientists since last year, when Department of Natural Resources officials began a $2 million study to determine whether the Asian oyster should be introduced into the bay.

DNR officials speak often of the "Oregon strain" of ariakensis, a reference to the small pool of oysters that came to Oregon from Japan and was bred in hatcheries.

"They do come from Oregon, but via southern Japan. Oregon was just a way port in their transition to the East Coast," said Stan Allen, an oyster geneticist at the Virginia institute. "It's a fine distinction, I have to admit. It doesn't imply that we know more about the biology. But it circumvents some of the other disease concerns that some people have."

Haphazardly bred

When ariakensis arrived in Oregon in the 1960s, the species was haphazardly bred through hatcheries to determine whether it was a suitable oyster for aquaculture. Although the oysters grew in the bottom of rivers under supervised conditions, the industry wasn't very interested in the species because it didn't reproduce in the wild, Allen said.

In the 1980s and early 1990s, scientists at Oregon State conducted further studies to see how the oyster would fare in aquaculture. Again, the industry wasn't interested, Langdon said.

The only ariakensis thought to be in Washington state are at Taylor Shellfish Farm, which tried to grow the species a few years ago without success. Taylor's public affairs manager, Bill Dewey, said the company is keeping a few dozen Asian oysters around in case there is a market for the product in Maryland.

"It's not been a species that's worked out the few times we've tried to work with it," he said.

Tom O'Connell, who manages the DNR's estuarine and marine fisheries program, acknowledges that his department's statements about ariakensis on the West Coast might have been misconstrued.

"When we make that statement, we need to clarify that yes, these animals have been out there on the West Coast, but they haven't been used widely," he said. "We get so involved with so many details, we have kind of overlooked the possibility that we need to clarify it to the public again."

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