If you like to swim in Michigan's inland lakes, you've probably encountered some weeds that give you the willies. Some of those weeds are worse than others and have become more than just a nuisance.
Eurasian watermilfoil looks a bit like seaweed and becomes so dense, it gets tangled on boat motors and people.
Jo Latimore is an aquatic ecologist at Michigan State University.
She says Eurasian watermilfoil grows very quickly and doesn't have a lot of things that feed on it.
"If it gets into a lake, it really has an opportunity to take over and crowd out the native plants, and really do some damage to the fish habitat in those lakes as well," Latimore says.
Latimore says cutting the weed just makes it spread efficiently.
"Mowing it down is a bad idea, because cut pieces actually will grow new roots and become new plants, so any fragments that get chopped up create more weeds," Latimore says.
"When it grows up to the surface of the water, it'll keep growing. It'll just start branching and spreading out across the surface of the lake, creating mats that are very difficult to get through for people, boats or even fish," she says.
Targeted herbicides and a native insect that likes the plants can be used, but both techniques are expensive.
Latimore says volunteers across the state are helping to identify the invasive weed and educate lake-dwellers and boaters about how it spreads.
For more information, visit Michigan Clean Water Corps at micorps.net