Virus devastates fish farm stock
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More than 500 tonnes of young salmon are heading to the rendering plant after a deadly fish virus was found at two separate B.C. farms.
The Canadian Food Inspection Agency (CFIA) confirmed Tuesday that both Mainstream Canada’s Miller Channel farm and Grieg Seafoods’ Culloden Point farm are contaminated with Infectious Hematopoietic Necrosis Virus (IHNV).
Grieg Seafoods says there are about 150 tonnes of Atlantic salmon at its infected Jarvis Inlet site near Campbell River. Mainstream Canada’s problem farm at Clayoquat Sound houses about 400 tonnes of Atlantic salmon.
The CFIA has ordered both companies to cull all the fish at those farms to contain the disease.
Not all salmon at the Grieg Seafood farm carry the virus, but Stewart Hawthorn, managing director, said “the humane thing to do” is to cull the fish before they get sick.
Dr. Gary Marty, fish pathologist with the B.C. Ministry of Agriculture, said infected Atlantic salmon lose most or all of their blood-producing cells, making them unable to oxygenate their blood or fend off disease. Fish then become lethargic, with a swollen belly, bulging eyes and hemorrhaging at the fins.
Marty said it's likely the farmed salmon contracted the disease from wild salmon, which are naturally immune to the disease. The only other possible cause, he said, would be if someone deliberately infected the Atlantic salmon with the disease.
It’s the second time this year Mainstream Canada has had to remove all its fish from an IHN-infected site in Clayoquat. The company’s Dixon Bay farm tested positive for the virus in May.
"This happens to be the year of IHN," said Laurie Jensen, spokesperson for Mainstream Canada.
Hawthorn said this current case of IHN is a first for Grieg Seafood, and it's unusual for the industry, too.
The last outbreak of IHN was in 2003, when 36 individual farms were infected, said Marty.
That event led to major reforms in B.C.’s fish farming industry. Fish farm companies now practice regular testing of their site, and they remove fish as soon as the virus is detected.
"Hopefully this will be the last year of IHN in farmed fish,” she said.
Both Mainstream Canada and Grieg Seafoods sell fish to domestic markets, but most of their product is distributed to the U.S.
IHN is not harmful to mammals, and heat involved in the rendering process kills off any traces of the virus.