The Minnesota Department of Natural Resources says more boaters understand the state's invasive species laws, and as a result the rate of violations is going down.

Of the more than 168,000 boats inspected in 2015, 3 percent arrived at lakes carrying plants or invasive species, according to a KSTP-TV report. But 95 percent of boaters had pulled the drain plug as required — the highest rate since the DNR started tracking inspections two years ago.

Zebra mussels were found in several new lakes this summer. The DNR says at least 550 of Minnesota's 11,000 lakes have some kind of invasive species.

Ann Pierce with the DNR says as more lakes become infected, people have to be more diligent.

On its website, the DNR says species on its watch list, for land and water, include zebra mussels, Eurasian watermilfoil, common buckthorn and emerald ash borer.

associated press, STAFF