The salt spread on roads during harsh winter storms brings temporary relief to drivers racing down icy roads, but wreaks havoc on vulnerable ecosystems nearby.

In some cases, road salt is destroying them altogether.

An extensive five-year study published this week by researchers at the University of Toronto Scarborough found that Frenchman’s Bay, a coastal inland bay in Pickering considered the “jewel” of the city’s waterfront, is a stew of harsh contaminants with levels far exceeding provincial water standards.

The pollution has reduced the number of fish, lowered the aquatic diversity and is destroying the provincially significant wetlands around the bay.

Swimming among the few fish are “startling” levels of E. coli, lead, chloride and aluminum, said Nick Eyles, a professor of geology who led the study.