Road Salt and Lakes | dochertylab

Road Salt and Lake Microbial Communities

In Michigan, winter is often coupled with the application of many tons of salty deicers onto our major roadways. While this standard practice creates safer driving conditions, it also leads to the deposition of astronomical amounts of salt into the lakes in urban areas. Once there, salt tends to remain in these waterways permanently, causing long term damage to the lake. In addition to causing adverse effects to fish and other aquatic animals and plants, salt from deicers can have an interesting effect on lake geochemistry. Lakes typically undergo a process called "turnover" in the fall and spring months, whereby deeper lake water is exchanged with surface lake water, allowing oxygen to become replenished at the lake bottom. However, addition of salt changes the density of the lake water, leading to a reduction or even absence of lake turnover events. As a result, the bottom of the lake remains permanently depleted of oxygen. Our work examines how lake microbial communities are impacted by this anoxic effect caused by road salt. Specifically, we focus on the effects of road salt on water column bacterial communities and on the activity of methane-producing Archaea (called "methanogens"). We are currently collaborating with WMU geochemist Dr. Carla Koretsky to explore these questions in three Kalamazoo area lakes (Asylum Lake, Woods Lake, North Lake).

Funded By:

Michigan Department of Environmental Quality