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%.