Environmental advocates say road salt levels in southern Ontario waterways have hit record highs, making some as salty as the ocean.
World Wildlife Fund Canada says its new maps tracking chloride from road salt show levels in many rural and urban southern Ontario waterways are increasing dangerously.
The organization says road salt's chloride component is toxic to freshwater species and ecosystems.
It says runoff from winter use is affecting creek and river habitats for species like fish, frogs and mussels, and endangering their survival during the spring and summer spawning season.
The organization says more than seven million tonnes of road salt are used in Canada each winter by public road agencies, while use by small towns and private sector companies is not currently tracked in Ontario.
It says the maps are based on data collected during the summer months and allow researchers to compare chloride levels over more than a decade.
"While healthy levels for aquatic life should be less than 120 micrograms per litre, our maps show some areas in southern Ontario currently have levels greater than 1000 mg/l year-round," Elizabeth Hendriks, WWF Canada's vice-president of freshwater, said in a statement.
"Ontario is over-salting its parking lots, sidewalks, and roadways. A small pill bottle or salt shaker is all that's needed to melt the equivalent of a city sidewalk slab."
