Strategy for lake invaders: Slow the spread
ALEXANDRIA, Minn.—With a steady stream of reports of zebra mussels and other aquatic invasive species getting into lakes, the battle to stop these invaders might look bleak.
But there are rays of hope, Minnesota Department of Natural Resources Commissioner Tom Landwehr recently told Forum News Service.
He said that efforts to educate boaters, anglers and the general public about zebra mussels are making a difference.
"Our programs to slow the spread are working," he said, adding that since there is no 100-percent effective treatment to eliminate zebra mussels, that's about the best the state can hope for.
As of March, less than 7 percent of Minnesota's more than 11,000 lakes are on the infested waters list. Less than 3 percent of lakes are listed as infested with zebra mussels.
Landwehr believes more people are heeding the DNR's main advice:
• Clean all visible aquatic plants, zebra mussels, and other invasive species from watercraft, trailers and water-related equipment before leaving any water access or shoreland.
• Drain water-related equipment and and livewells by removing drain plugs before leaving a lake access or shoreline property. Keep drain plugs out and water-draining devices open while transporting watercraft.
• Dispose of unwanted bait, including minnows, leeches and worms, in the trash.
Landwehr said boaters are getting more cooperative in obeying state laws that make it illegal to move invasive species out of an infested lake. "They understand the implications," he said, which can include up to $500 in civil penalties.
Even though the DNR has ramped up its educational efforts to stop aquatic invasive species, the challenge is daunting, Landwehr said. He noted that Minnesota has more than 800,000 registered boat owners and out of the 6,000 lake accesses in the state, the DNR manages only 1,500 of them. There are also private accesses.
"With five million boat launchings every year, it's challenging," he said.
Landwehr ruled out an idea for the state to put boat inspection officers at every public access. Some counties are trying to do that, but Landwehr said it would not work on a statewide level.
"It's physically impossible and financially impossible," he said.
Landwehr added that having an officer check every boat at an access could also cause lengthy and unacceptable delays.
"The longest someone should have to wait to launch a boat should be 15 minutes," he said. "If it's more than that, you're restricting access to public waters."
The best solution for eliminating zebra mussels may rest with University of Minnesota researchers. Landwehr said the Legislature has provided new funding sources that could lead to breakthroughs, such as the herbicide treatments that are used to stop purple loosestrife and sea lamprey.
A biopesticide, Zequanox, provides some control of zebra mussels if an infestation is spotted early and can be contained to a small section of the lake, Landwehr said. It's not as effective in open water and it's expensive, he added.
So unless a silver bullet comes along to stop zebra mussels, Landwehr believes the best approach is to spread the word about aquatic invasive species and how to prevent them from getting into another lake.