“Wait a minute, I didn’t think these were supposed to be in the lake.”
An undergraduate lab in UW-Madison’s Zoology 315 course had surprised Vince Butitta, a Center for Limnology graduate student, after pulling a metal post and its passenger out of Lake Mendota Wednesday.
While wading in the water in search of aquatic insects, the group accidentally stumbled upon a zebra mussel—the newest known member of Lake Mendota’s invasive species, according to a UW-Madison Center for Limnology news release.
Center for Limnology graduate student Colin Smith investigated several sites in the lake and found the species at low abundances in Lake Mendota so far. Only a few per square meter have been found, according to the release.
Zebra mussels are filter feeders that can increase water clarity, with a single adult filtering up to a liter of water per day, according to the release.
The species currently inhabits several lakes in Wisconsin, but the effects zebra mussels can have on the water are not always good.
Although the species filters through algae blooms, they can also cause large mats of algae to begin to grow along the bottom of lakes. Eventually, these mats can break free and create noxious odors upon washing up on shore and decomposing, as said in the release.
They can also drastically change the ecosystem dynamics of the lake by concentrating nutrients near the bottom, causing open-water habitat fish, like walleye, to struggle.
These being among other problems, the Wisconsin Department of Natural Resources urges people to exercise caution when moving aquatic gear from one lake to another to avoid moving populations.
