Are diseases spread from farmed to wild salmon?
According to Fisheries and Oceans Canada, there are many reasons why fish become susceptible to disease: fluctuations in water temperature, water level or salinity, natural physiological changes that fish undergo (e.g. when salmon migrate from salt to fresh water), abundance of populations, or a combination of factors. Diseases that pose a risk to the salmon industry, such as sea lice or infectious hematopoietic necrosis (IHN) were identified before salmon farms arrived in our coastal waters. There is no evidence to indicate that disease outbreaks at salmon farms have resulted in any increase in diseases in wild salmon. In fact, research indicates that farmed salmon are at a higher risk of contracting a disease from wild fish than vice versa. It is generally accepted that fish pathogens move between wild and farmed stocks. However, the magnitude and significance of movement of microorganisms between these stocks is unknown. It is reasonable to assume that wild and farmed fish are expos
