In a new study published today in the online journal Plos One, Alex Morton and co-authors Drs. Rick Routledge and Molly and Fred Kibenge trace the Norwegian variant of piscine reovirus (PRV) in samples of wild salmon. Sampling from regions where salmon have little chance of passing a salmon farm disclosed very low levels of the pathogen (5%); while Fraser River stocks were as much as 45% infected.  Significantly, the rate of infection was highest in the lower reaches of the Fraser River, as compared with the Upper Fraser where infection rates dropped 50%. This finding tends to indicate that wild salmon exposed to salmon farm effluent are less able to withstand the stress of migrating through the challenging climb into the Upper Fraser watersheds. The pathogen, PRV, has now been shown to be the causative agent of a disease known as Heart and Skeletal Muscle Inflammation (HSMI), that can weaken fish, making them less able to swim, avoid predators and complete their long migrations.

Executive Director Karen Wristen issued the following statement:

"We are indebeted to Alex and her co-authors for this paper. In light of the recent recommendation of COSEWIC that several stocks of Fraser River salmon be listed as endangered, threatened or of special concern, we believe the federal government must take immediate action to remove infected farmed salmon from open netpens on salmon migration routes.  It is intolerable that the Minister should continue to permit diseased farm fish to be deliberately introduced into the marine environment."

Read the research paper here.

Read Alex's media release here.