B.C. fishery scientists are developing a new generation of genetic tools to find diseases that are undermining the health of wild Pacific salmon and track them back to their source. More than 90 per cent of juvenile salmon that migrate from fresh water to live as adults in the ocean die before they return to spawn, according to the researchers.
Disease is believed to be responsible for excessive mortality, according to Brian Riddell, CEO of the Pacific Salmon Foundation. But very little is known about the incidence of disease among wild salmon, in part because wild salmon are very difficult to observe once they enter the ocean and because weakened fish are eaten by predators, leaving no evidence of the cause of illness.