People come from all over the state and country to visit the great northwoods town, Minocqua.

That's why it's vital the area's lakes and rivers stay clean and free from invasive species.

Again this year, aquatic invasives are a concern among the Dept. of Natural Resources and nature lovers.

Major predators include eurasian water-milfoil, purple loosestrife and zebra mussels.

"It's a huge issue because up here we depend on tourism and keeping our lakes nice and clean, because people come up here to boat, fish, go swimming," said Deputy Warden John Preuss, DNR.

He urgs boaters and anglers to clean off their boats and equipment when coming off the lake.

It's also important to drain water from the boat, motor, bilge, live wells and bait containers before leaving the landing.

Thorough cleaning is necessary, since many types of invasive species are tiny and can't be seen with the naked eye.