A snowy winter sheds light on road salt’s impact on Minnesota’s lakes
During the depths of winter, data collection began for a new St. Croix Watershed Research Station (SCWRS) project about Minnesota lakes.
The project, made possible by a three-year, $1.2M grant from Legislative-Citizen Commission on Minnesota Resources’ (LCCMR) Environment and Natural Resources Trust Fund, is digging into the impacts of road salt on lakes in Minnesota.
Dr. Mark Edlund is senior scientist at the Research Station, which is a part of the Science Museum’s Center for Research and Collections. “There’s been a lot of work done on how road salt changes how a lake is structured,” he says. “This project is going to help us understand the biological effects.”
The project will use three different strategies to create a picture of how road salt is affecting lakes:
Research Station staff will monitor a set of fifteen lakes throughout Minnesota (three in the Alexandria area and twelve in the metro region, including Lake Phalen, Bde Maka Ska, and Lake Minnetonka). The team will be collecting data to understand these lakes’ biological and chemical profiles, as well as their physical traits and general water quality.
The Research Station will also leverage their expertise in sediment analysis, collecting sediment cores from lake bottoms to gain a better understanding of their history. As they’ve gotten salinized, how has their biology and chemistry changed?
Station staff will be studying the genetic responses of keystone species like zooplankton, on which many other species depend, in the study lakes. How are they changing in response to their changing environment?
In addition, Edlund says that the team is interested in exploring the impacts of road salt alternatives that are on the market now. “One of the things that happens when you add salt to a lake is that it creates a layer on the bottom of denser, salty water,” he says. “We’re interested in how that layer affects nutrient dynamics, as well as how road salt alternatives might have an impact. We’ll do experiments in the lab to expose sediment cores to different concentrations of different deicing solutions to see what advantages they provide to the environment.”
The grant, which is the biggest the SCWRS has ever received from LCCMR, allowed the Station to invest in new equipment and expand its team. Research fellow Mari Leland will help the team carry out the research.
After some initial scouting in the fall, the data collection began in earnest in January 2023, with Edlund and Leland venturing out to collect sediment cores. See Edlund and Leland in action on Instagram!
