Grant: Strategic Projects - Group

Growth in global fish production is due almost entirely to the increase in fin fish production by aquaculture, representing more than 30% of total fish production for human consumption. The largest cause of economic losses in aquaculture is from fish diseases, with oomycete fungal infections being second only to bacterial infections in terms of their impact. These fungi can cause saprolegniosis, a disease observed in both the egg stage and adult fish, causing illness and mortality. Globally, the top ten commercial species of fin fish are all known to be affected by this disease. The species Saprolegnia parasitica is the most important causal agent of this disease, infecting the aquaculture species of salmon, trout and catfish, causing economic losses estimated in the tens of millions of dollars. Anti-fungal treatments will eliminate the fungus, but not prevent disease recurrence, as the fungus likely occurs in the water source that supplies a facility. Presently, the origin and diversity of the pathogen remains undescribed. As well, risk factors that contribute to disease outbreaks in fish are poorly understood, making the development of effective disease management plans impossible. We intend to address a major fish health issue that affects productivity and the overall health of fish stocks. An initiative is required to reduce the economic impact of this disease. This will be facilitated through the development of a molecular platform of technologies (including DNA fingerprinting) that will permit an evaluation of the genetic structure of the pathogen population, epidemiological studies in Canadian fish hatcheries, and assist in the development of improved management practices for this fungal disease in freshwater fish aquaculture.