Promoting Watershed Security in Ontario – Water for People and for Nature

Sept 13 – It has just been revealed that the government quietly made the report of the Provincial Climate Change Impact Assessment available, but without any media release. On aquatic security, a key aspect of the report states, on page 230, “Aquatic ecosystems are vulnerable to the impacts of climate change because once degraded they can lose functionality and factors such an increased surface water temperature can have detrimental effects on aquatic biota such as fish (Poesch et al., 2016; Sutton and Jones, 2021; Smith et al., 2021). Direct climate change impacts to aquatic ecosystems include warmer temperatures, changes in precipitation, and shifting wind patterns affecting water budgets and thermal regimes; these have cascading effects, such as changes in hydrology, reduced ice cover on lakes, nutrient cycling, groundwater flow, sedimentation patterns, and mixing in lakes (Poesch et al., 2016; Woolway et al., 2020). These physical changes affect the quality and quantity of aquatic habitats and the health of ecological functions. Indeed, the combination of climate and non-climate stressors can diminish the health of aquatic ecosystems. For example, the impact of climate change on extreme precipitation events like intense downpours is related to runoff events, which, combined with nutrient and other pollution runoff can result in algae blooms, the loss of rare plant species, and reduction in wildlife diversity (Moore et al., 1989). See the full report at Ontario Provincial Climate Change Impact Assessment Technical Report – January 2023.