The effects of acidic deposition on aquatic resources in Canada: An analysis of past, present, and future effects

This report assesses the current knowledge of surface water acidification and its effects on aquatic biota in eastern Canada. We used a critical appraisal of recent research to draw answers to the important questions. What are the size, location, and current chemical condition of aquatic resources in eastern Canada that are thought to be vulnerable to acidic deposition. What are the extent and magnitude of chemical changes in surface waters of eastern Canada that can be attributed to acidic deposition. What evidence exists to support the hypothesis that biological changes in surface waters in eastern Canada have resulted from chemical changes associated with acidic deposition. How many aquatic systems in eastern Canada will become acidic at various levels of acidic deposition and within what length of time. What is the rate at which lake chemistry and aquatic biota improve when deposition is reduced. The aquatic resources evaluated in this assessment are in that area of Canada east of the Ontario-Manitoba border and south of 52/degree/N, excluding the Great Lakes, and encompassing part or all of the provinces of Ontario, Quebec, Newfoundland, Labrador, New Brunswick, and Nova Scotia. 202 refs., 19 figs., 7 tabs.