Further study urged on virus found in Pacific salmon

Reuters News
Posted: Oct 20, 2011 10:58 PM
Further study urged on virus found in Pacific salmon

By Nicole Neroulias

SEATTLE (Reuters) - U.S. senators from Alaska and Washington state called on Thursday for more investigation of a contagious and lethal fish virus recently detected for the first time in wild Pacific salmon, alarming marine scientists.

The infectious salmon anemia virus, previously limited to Atlantic salmon -- including an outbreak that ravaged Chile's farm-raised salmon industry in 2007 and 2008 -- was found in two out of 48 young sockeye salmon sampled from a British Columbia river inlet, researchers said.

The findings were announced on Monday in Vancouver by marine biologists from Simon Fraser University, who said the European strain of the virus they detected had only been identified before in farm-raised Atlantic salmon.

They said the research suggested that the virus in Canada originated from imports of Atlantic salmon and eggs into the Pacific Northwest, though no direct link has been confirmed.

Although highly deadly to salmon, the virus cannot infect humans, bears or other warm-blooded animals that consume the fish. However, any sharp decline in salmon populations would diminish a key food source for wildlife that prey on them.

Randy Ericksen, an expert at the Wild Salmon Center in Portland, Oregon, a nonprofit group that monitors and makes recommendations to protect Pacific salmon, called the findings "very alarming."

While the data is preliminary, he said, "the fact that they've found this virus in the wild Pacific salmon raises the question about how far this has really spread."

"Many of the salmon populations around the Pacific Northwest are listed under the Endangered Species Act, and this is another potential problem for them," Ericksen added.

Alexandra Morton, a Simon Fraser researcher who took part in the study and has been an outspoken critic of salmon farming practices, said the answer was to "turn off the source."

"Atlantic salmon have to be immediately removed," she said in a statement announcing the findings.

But James Winton, chief of fish health at the Seattle-based Western Fisheries Research Center, part of the U.S. Geological Survey, said it was far too early for drastic measures, given that farm-raised fish are regularly screened for disease.


The infectious salmon anemia (ISA), a fish influenza first discovered in Norway in 1984, was blamed for the loss of 6,000 jobs when it struck Chile, ranked as the world's No. 2 salmon producer, with devastating effect several years ago.

Much is at stake in the North Pacific, as well. Sockeye alone account for 12 percent of a $3 billion Pacific salmon commercial fishing industry that encompasses the Pacific Northwest, Canada, Alaska, Russia and Japan, according to a 2009 report from the Wild Salmon Center.

Alaska's two U.S. senators, Republican Lisa Murkowski and Democrat Mark Begich, joined Democratic Senator Maria Cantwell of Washington state in calling for a multi-agency federal task force to evaluate the threat posed by the virus. They offered an amendment to an appropriations bill directing the panel to report to Congress on its findings.

"We need to act now to protect the Pacific Northwest's coastal economy and jobs," Cantwell said in a statement.

James Anderson, a professor at the University of Washington School of Aquatic and Fishery Sciences, agreed that more research is needed, describing the initial report as "important, emotional and fraught with uncertainty."

In general, wild fish tend to be hardier and less susceptible to disease than their farmed cousins due to natural selection, he said.

On the other hand, wild salmon experiencing stressful conditions, such as threats to their habitat and food supply, may become more vulnerable over time, researchers say.

It will take at least a year for independent researchers to determine how widespread the virus may be among wild Pacific salmon and determine what steps should be taken, Winton said.

(Editing by Steve Gorman and Peter Bohan)