Public Update (2): IHN and BC Salmon Farms
BCSFA, Friday, June 1, 2012
Forty nine of the active salmon farms in BC have now come back testing negative for the Infectious Haematopoietic Necrosis (IHN) virus.
IHN is an endemic virus found naturally in the Pacific Ocean. The virus can be carried by wild salmon, trout and herring, however studies have shown that because of their historical exposure to it, they have a natural resistance to it. Atlantic salmon however are highly susceptible to the virus and it can cause high mortalities on farm sites. To view a fact sheet about IHN, click here.
IHN poses no risk to human health. The Canadian Food Inspection Agency’s fact sheet on IHN can be found here.
Since our last information bulletin dated May 25, 2012:
Results from an additional 19 tests have returned negative in the last week. That means that to date, a total of 49 farms operating in BC have completed testing, proving negative for the virus. Samples from roughly 7 more farms are in laboratories waiting processing. All other operating farms’ recent routine sampling by DFO has been negative for the virus as well.
The CFIA has lifted the quarantine put in place on Grieg Seafood’s Ahlstrom farm site after follow up testing - both on the original samples and additional subsequent samples -came back negative for the virus.
Further testing continues on Mainstream Canada’s Bawden farm site where a weak positive was found last week. The company is preparing harvest plans.
The CFIA formally confirmed the IHN finding at Mainstream’s Dixon Bay farm, the initial finding of the disease. The farm had completed depopulation 10 days before, action the company took proactively in response to initial testing. Mainstream Canada has shared the lab results from that testing here.
The BC Salmon Farmers Association advises that their public farm tour program has been postponed until further notice, as all companies are on increased biosecurity alerts awaiting further sampling and direction by the CFIA.
BC's largest salmon aquaculture company confirms no IHN virus at its farms
Marine Harvest Canada, June 1, 2012
Marine Harvest Canada, BC's largest salmon farming company, confirms that all of its salmon farms have tested negative for the presence of Infectious Haematopoietic Necrosis (IHN) virus.
"All 27 of our salmon farm sites have now been tested for presence of IHN," says Dr. Diane Morrison, Marine Harvest's Fish Health Director. "The tests have confirmed that IHN is not present at any of our farms."
IHN is commonly referred to as 'sockeye disease' and is naturally present in almost all stocks of sockeye salmon. While Pacific salmon (genus Oncorhynchus) are known to be resistant to the IHN virus, it can be fatal to Atlantic salmon (genus Salmo).
Mainstream Canada (a BC salmon farming company not affiliated with Marine Harvest Canada) confirmed IHN at one Atlantic salmon farm on the West coast of Vancouver Island near Tofino. The fish were quickly and humanely disposed of to prevent spread to nearby farms.
"We are very happy that our farms are free from IHN," says Clare Backman, Marine Harvest's Sustainability Programs Director. "but transmission can come from passing wild fish, so we will continue to be diligent in regards to fish husbandry and biosecurity protocols to ensure our fish remain healthy."
The presence of IHN in wild and farm-raised salmon poses no risk to human health.
Marine Harvest Canada produces one-half of British Columbia's largest agricultural export - farm-raised salmon. Its' processing plants, marine and land based operations are located on and around northern Vancouver Island and the village of Klemtu.
The IHN virus is naturally carried by wild Pacific salmon and is low risk to them, but can be a high risk to Atlantic salmon.
Fact Information, Mainstream Canada, May 31, 2012
For the first time since 2003, IHN (Infectious Hematopoietic Necrosis) virus was detected in our salmon, forcing a quick response.
But is this virus a risk to wild salmon?
History and science suggests it is not. The IHN virus is naturally carried by wild salmon and has been present for hundreds of years in the Pacific Ocean. It is found naturally in fish from Alasks to California, and has only been observed to be a concern for the tiniest wild salmon in high-density situations, such as hatcheries. Under natural conditions, the virus appears to pose low risk to even tiny wild salmon.
On the other hand, farmed Atlantic salmon are at high risk from the disease this virus can cause because they are not native to the Pacific Ocean and have not evolved a natural resistance to it like their Pacific cousins.
