Researchers with Simon Fraser University in British Columbia announced last month they had detected infectious salmon anemia, or ISA, in two wild juvenile Pacific salmon collected from the province’s central coast, prompting fears the influenza-like virus could wreck the salmon fishing industry in the Pacific Northwest.
“There’s no evidence that (the virus) occurs in fish off the waters of British Columbia,” Dr. Cornelius Kiley, a veterinarian with the Canadian Food Inspection Agency, said Tuesday, announcing results from the government investigation.
Government tests of the original 48 samples collected from B.C. researchers at a national laboratory have turned up negative for the virus, Canadian officials said. Additional tests performed on other samples have also turned up negative, because the quality of some of those samples was too degraded to be conclusive.
The results are consistent with independent testing conducted by a lab in Norway, officials said. While that lab found one weak positive reading among multiple tests, it also noted the sample was poor and results could not be reproduced, said Peter Wright, national manager for the Research and Diagnostic Laboratory System with Fisheries and Oceans Canada.
Officials are continuing to test samples for the salmon virus, which has affected Atlantic salmon fish farms in Chile, Maine, New Brunswick and other areas. It does not affect humans.
Rick Routledge, a researcher with Simon Fraser University who announced the detection of the salmon virus in October, said Tuesday that one positive reading by an independent laboratory in Norway shouldn’t be dismissed entirely.
“Given that he did get a positive reading once, from a degraded sample, I don’t feel comfortable with the notion that you could dismiss that out of hand,” he said. “I hope that further sampling and testing would continue.”
The news that Canadian officials had not detected the virus, however, was welcomed by B.C.’s salmon farmers.
“This is a significant result for everyone involved: researchers, regulators, wild salmon advocates, salmon farmers and our coastal communities,” Mary Ellen Walling, executive director of the B.C. Salmon Farmers Association, said in a statement. She added, “We hope this update will allay those concerns.”
The virus was initially detected in two of 48 juvenile sockeye salmon collected as part of a long-term study of sockeye salmon led by Routledge. Fred Kibenge of the Atlantic Veterinary College at the University of Prince Edward Island confirmed the presence of the virus in two fish.
The report that the virus had been detected in wild Pacific salmon for the first time on the West Coast, prompted concern by state and federal officials in the U.S.
U.S. senators have called for increasing surveillance, testing and research. Maria Cantwell, a Democrat from Washington, and Republican Lisa Murkowski and Democrat Mark Begich, both from Alaska, have also called for the National Oceanic and Atmospheric Administration to run its own tests on the salmon.
Meanwhile, Washington state officials have been working in recent weeks with U.S. agencies, tribes and Alaska state officials on a plan to sample additional fish for the virus.
Tuesday’s news isn’t likely to change plans to increase screening in Washington state, said John Kerwin, who supervises the fish health unit at state Department of Fish and Wildlife.
“I believe we need a surveillance program, given the uncertainties,” he said Tuesday, adding: “I’d rather err on the caution when we’re talking about our natural resources.”
“Regardless of this being a positive or negative (result), it’s not appropriate to ignore,” Dr. Jill Rolland, director of aquatic, swine, equine and poultry health program with the U.S. Department of Agriculture, said in an interview last week.
The virus was first reported in North America in Canada in 1996, and first detected in the U.S. in Maine’s Cobscook Bay in 2001.
“This is not the final end of the issue,” said James Winton, who directs the fish health section of the U.S. Geological Survey’s Western Fisheries Research Center in Seattle. He said he had not yet reviewed the details of the Canadians tests.
Plans in place for increased surveillance will continue, though perhaps without the immediate urgency had Canadian officials confirmed the virus, he said. The disease may not currently be here, but it’s still a threat if it is to be introduced in the future, Winton said.
“The fact that they can’t replicate the findings of the WHO lab does not necessarily negate the possibility that the virus is still escaping detection,” Winton said. “We don’t know right now.”