Crystal Lake Mixing Project
Crystal Lake is one of the most popular lakes in Vilas County, with thousands of families visiting each year. The sandy beaches and beautiful blue waters provide quite the scenic Northwoods backdrop for a day at the beach but, below the surface, it’s not such a pretty picture.
Rainbow smelt, an invasive fish first introduced to the Great Lakes in the early 1900’s have now made their way into Wisconsin’s inland lakes. And these small fish have wreaked havoc on the food web. In Crystal Lake, for example, yellow perch have nearly disappeared.
Now a team of UW-Madison limnology and engineering students and researchers are conducting a whole-lake experiment to see if they can rid the waters of smelt. While traditional invasive species control measures would be basically poisoning the entire lake and starting over, researchers are interested in seeing if there’s a better way.
Since smelt are the only cold water species in Crystal Lake, they hope to mix the lake to remove this cold water habitat and stress smelt past their thermal tolerance.
This summer, the Crystal Crew designed and built the GELI (Gradual Entrainment Lake Inverter) mixing system to disrupt temperature stratification by vertically mixing the water. See the Crystal Crew in action this summer as they build the project from the bottom up. And stay tuned next summer when the GELIs finally get a chance to do what they’ve been built to do!