Salmon dissection to be analysed. (Photo: al.gov.bc.ca)

Mainstream detects IHN virus at Vancouver farm

CANADA
Wednesday, May 16, 2012, 23:20 (GMT + 9)

Mainstream Canada this week communicated that it has identified infectious haematopoietic necrosis (IHN) at its farm in Dixon Bay on the west coast of Vancouver Island.

The company’s health monitoring programme detected the virus and took effective action. Canadian authorities have already been notified and further measures, including decisions on killing the fish, will follow normal routines.

The site contains approximately 500,000 fish with an average weight of about 1 kg each.

"We are very concerned about this fish health event and are taking every step to make sure it is contained and any risks minimized," said Fernando Villarroel, managing director of Mainstream Canada.

"This shows our disease monitoring programmes work. We were able to quickly detect IHN while in its early stages and react decisively," he stressed, Times Colonist reports.

IHN, which is harmless to humans, is naturally carried by and poses no danger to Pacific salmon, trout and herring, as these species have developed a natural immunity. However, the virus is highly lethal to Atlantic salmon; it attacks the kidneys and spleen of the fish and can lead to rotting flesh and organ failure.

"This is the first diagnosis of IHN among farmed Atlantic salmon in British Columbia (BC) since 2003," said Gary Marty, BC Animal Health Centre fish pathologist.

The Canadian Food Inspection Agency (CFIA) is running its own investigation and a Fisheries and Oceans (DFO) laboratory is running additional tests. CFIA will visit the farm this week and decide whether to kill the fish and, if so, how many.

"This year now turns out to be a very bad year for IHN virus and we still don't completely understand why," said fish virologist James Winton, Vancouver Sun reports. "A lot of the sockeye were coming back with higher percentages and higher amounts of the virus, so it's not surprising that we're seeing a cycle again in some of the farms.”

Biologist Alexandra Morton, a vociferous opponent of open-net pen salmon farms, said she is glad Mainstream is thinking of killing its farmed fish, and thinks the firm should also test wild fish in the area.

"When you have 600,000 fish with IHN in one area, it amplifies the disease," she explained. "It's like being on a football field with someone with a cold and being with 600,000 people with colds."

By Natalia Real
editorial@fis.com
www.fis.com

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