New research shows that the runoff from road salt into Mirror Lake in Adirondack Park, New York, USA, prevents natural water turnover, posing a risk to the natural ecosystems.
Between 90 to 450 pounds of salt is applied per lane-mile in New York State, 90% of which runs into local bodies of water. With road salt being applied on average for 76 days a year in New York State since the 1940s, the environmental impact on local wildlife is immeasurable.
A new paper published in Lake and Reservoir Management combined research from the Ausable River Association and the Adirondack Watershed Institute monitored the water quality of Mirror Lake.
The research team found that road salt runoff has prevented spring mixing of the water column, creating more anoxic water conditions that limited habitat availability of the native lake trout.
“Mirror Lake is the first in the Adirondack Park to show an interruption in lake turnover due to road salt”, says Dr. Brendan Wiltse from Ausable River Association, who led the study.
Located in the Village of Lake Placid, Mirror Lake is the most developed lake within the Adirondack Park which is a publicly protected area greater than Yellowstone, Yosemite, Glacier and Grand Canyon National Parks combined.
As with many other northern temperate lakes, Mirror Lake experiences ‘dimictic’ turnover, a natural process where wind and less stratified water conditions of spring and autumn allows the mixing of the water column that redistributes oxygen and nutrients throughout the lake.
The high levels of surface-water chloride were first noticed in 2014 as part of the survey from the Adirondack Lake Assessment Program, as so the following year, Wiltse and colleagues began monitoring Mirror Lake more intensely.
“This resulted in a longer duration and spatial extent of low oxygen conditions in the deepwater…it may also put the lake at a higher risk of algal blooms due to internal phosphorus loading…if the lake were to stop mixing in the fall it is possible the lake would experience a winter fish kill,” Wiltse explained.