Report: Lake Michigan Getting Saltier

lakemichiganclear-15
lakemichiganclear-15

The Great Lakes hold about one fifth of the Earth’s fresh water, but a new report indicates they’re getting saltier. Lake Michigan used to sit at a level of one to two milligrams of chloride per liter of lake water. Now, that concentration has risen to nearly 15 milligrams per liter. Hilary Dugan, with the University of Wisconsin’s Center for Limnology, says it’s still a low level for a water body as large as Lake Michigan, but rising chloride levels could pose problems for plants and animals in the smaller lakes and tributaries that feed into it.

“If anything, we’re just hurting those native freshwater species that are adapted to, you know, Wisconsin waters that basically have no salt in them. And now, you know, we’ve increased the salt ten-, hundredfold, depending on what body of water we’re looking at.”

Dugan says salt levels have to hit roughly 250 milligrams per liter to pose a serious risk to plants, animals, and humans, and notes virtually all the chloride pollution is from road salt. She adds people can reduce pollution in lakes and streams this winter by limiting their use of salt on roads, driveways and sidewalks.