An overview of climate change and prevalence of bacterial diseases in salmonid aquaculture

Food fish farming is regarded as one of the most important sectors of the aquaculture industry. Salmon farming is a major contributor to the growth of the aquaculture sector. Climate change is predicted to have a complex impact on aquatic ecosystems, including fisheries and aquaculture. Climate change can cause a fluctuation in water temperature of rivers, lakes, seas, and oceans. This can change the pattern of ocean currents and marine productivity to be redistributed, especially to higher latitudes, and reduce the global concentration of phytoplanktons, increasing ocean acidity, creating deoxygenated zones, and inducing episodic shocks to marine systems. However, the impact of climate change on fish health is not limited to the physical changes in the environment. A change in climate can also influence the incidence of infectious diseases by shortening generation times and/or increasing the survival rates of the pathogenic agents, improving disease transmission, and enhancing the host's susceptibility to the pathogens. The actual impact of climate change on infectious diseases, particularly those caused by bacterial agents, is not fully understood in both wild and captured fish species. This review addressed the impact of climate change on outbreaks of salmonid bacterial diseases and discuss the present gaps.