With the recent IHN outbreaks in BC feedlots, the industry has been quick to get the message out that IHN is only lethal to Atlantics, not wild salmon. But is this fact or just another line of fiction from an industry determined to grow it's product in our oceans no matter the cost.
Science has determined that wild salmon has developed immunity to the virus however it is a carrier of the virus. Feedlots take this bit of science and blame the wild salmon for the outbreaks in their feedlots. They try to portray that feedlots are the victims rather than the perpetrators of this disease.
A topic that we don't hear a lot about is how the IHN virus is lethal to salmon fry in fresh water.
"The IHN virus is well recognized as a lethal pathogen to fry sockeye salmon in freshwater." http://www.cohencommission.ca/en/pdf/TR/Project1-ExecutiveSummary.pdfHere's the problem..... The feedlots that are currently being culled as a result of an IHN outbreak have been spewing IHN viruses at a rate of millions of virus per second, as they replicate very quickly. The feedlots want you to believe that they are pro-active when an outbreak occurs by disinfecting their equipment and "isolating" the pens... Apparently they are unaware that the virus is generated in the water and is impossible to contain!
While this is going on, millions of salmon are swimming past these IHN cesspools. Naturally the wild salmon are being infected and while they may not die from the virus, they become carriers. Swimming up the fresh water streams they in turn infect other wild salmon. Unlike sea lice which dies within days of being in contact with fresh water, IHN can survive for up to 7 weeks.
"The IHN virus has been demonstrated to survive in fresh water at 10 "C for 7 wk (Wedemeyer et al. 1978). " http://www.int-res.com/articles/dao/16/d016p111.pdf While most salmon fry have left their fresh water streams and are in the ocean, last years sockeye fry are still swimming in a fresh water lake downstream of the river they were born in. As the returning salmon mingle with the sockeye fry they are transferring the virus to the fry ensuring certain death for the fry before they even reach the ocean.
Is this another dirty little secret that the feedlots and government haven't revealed and is the cause of our low sockeye returns?? Has a study been done correlating the IHN infections in the feedlots, to the demise of our sockeye runs? Why not?