Fish and Shellfish Health Session. Climate change and aquaculture in Canada: potential impacts on aquatic animal health presentation summary

For a number of important human and terrestrial animal diseases climate change has been identified as one of several factors affecting changes in disease distribution, prevalence and intensity. However, there remains uncertainty with respect to the relative importance of climate change as a driver. Determining the magnitude of the effect caused by climatic factors from those caused by numerous other abiotic and biotic environmental, behavioural and social factors remains the challenge. It is well recognized that features of the host (or host population), the disease causing agent (infectious or non-infectious agent or their populations thereof) and the environment can change independently or as a result of complex interactions between any combination of them. For this reason our ability to predict disease occurrence outside of very controlled laboratory conditions is poor. When you consider the high level of uncertainty that surrounds the direction and magnitude of climate change and how these effects will be expressed in aquatic systems it is easy to realize that our ability to predict how climate change will effect diseases in aquaculture is very limited. At a very general level climate change effects on aquatic systems will include changes in: temperature, pH (acidification), patterns of precipitation/evaporation, water column structure/ stability and patterns of circulation and the frequency and magnitude of storm events. It is important to remember that these effects will be occurring in the presence of other small and large-scale environmental changes that are not necessarily caused by climate change (e.g. changes in land use; eutrophication to name a few). These changes may impact aquatic animal health directly or through their interactions with climate induced changes.