Lethal virus detected in wild Pacific salmon ‘a cataclysmic threat’
By CORNELIA DEAN and RACHEL NUWER, The New York Times
17 October 2011
A lethal and highly contagious marine virus has been detected for the first time in wild salmon in the Pacific Northwest, researchers in British Columbia said Monday, stirring concern that it could spread, as it has in Chile, Scotland and elsewhere. Farms hit by the virus, infectious salmon anemia, have lost 70 percent or more of their fish in recent decades. Until now, however, the virus never had been confirmed on the West Coast of North America. The virus does not affect humans. The researchers, from Simon Fraser University and elsewhere, said at a news conference in Vancouver that the virus had been found in two of 48 juvenile fish collected as part of a study of sockeye salmon in Rivers Inlet, on the central coast of British Columbia. The study was undertaken after scientists observed a decline in the number of young sockeye. Richard Routledge, an environmental scientist at the university who leads the sockeye study, suggested the virus had spread from the province’s aquaculture industry, which has imported millions of Atlantic salmon eggs over the past 25 years, primarily from Iceland and Scandinavia. He acknowledged no direct evidence of that link existed, but noted the two fish had tested positive for the European strain of infectious salmon anemia. The virus could have “a devastating impact” not only on the region’s farmed and wild salmon but on the many species that depend on them in the food web, such as grizzly bears, killer whales and wolves, Routledge said. “No country has ever gotten rid of it once it arrives,” he said in a statement. The only barrier between the salmon farms and wild fish is a net, Routledge noted at the news conference, opening the way for “pathogens sweeping in and out.” No vaccine or treatment exists for infectious salmon anemia. […] Alexandra Morton, a researcher and activist who collected the sockeye samples and is an outspoken critic of salmon farming practices in British Columbia, called the virus “a cataclysmic threat” to both salmon and herring, which also can contract the disease. “If we test 5 million fish and found two sick, OK,” she said. “But 48 in the middle of nowhere?” The inlet where the samples were taken is 60 miles from the nearest salmon farm, the researchers said. […]
