A deadly (to fish, not humans) and highly contagious European salmon virus was found in two Canadian sockeye. The suspected source is Atlantic salmon farmed in British Columbia. It truly is a small world, isn't it?
Biologists studying the decline of Fraser River sockeye salmon discovered the disease, infectious salmon anemia, in two of 48 smolts that were tested. The virus is potentially catastrophic for the B.C. salmon farming industry. Chile lost 70% of it's farmed salmon (the same Atlantic variety farmed in Canada) to the disease. It is unknown how much of a threat the virus poses for wild salmon stocks, but the Seattle Times reports that some marine biologists are very, very worried.
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.
Fishery experts with no connection to the study agreed the threat was serious. James Winton, who leads the fish health research group at the Western Fisheries Research Center in Seattle, an arm of the U.S. Geological Survey, called it a "disease emergency" and urged that research begin at once to determine how far the virus had spread.
According to the federal Centers for Disease Control and Prevention, infectious salmon anemia virus morphed from a benign form in nature into a "novel virulent strain" when salmon stocks entered Norway's densely packed salmon farms. Rather than getting picked off by a predator, a sick fish would undergo a slow death in a crowded pen, shedding virus particles.
The source of the virus in the B.C. sockeye is not yet known. Fish researcher Rick Routledge cites fish farms as the "only plausible source", yet no farmed fish have ever tested positive for the virus. Fish farming critics suspect that perhaps the testing hasn't been very thorough. If the disease is found in farmed populations, those populations will most likely be destroyed.
There is no reason to panic, but the potential for devastating effects on wild fish populations and the dependent food chain is cause for concern.