“Has anyone anywhere ever eradicated an aquatic invasive species?” someone called out from the back of the room. “Hmmm, let me think about that,” Steve McComas said. “Yes! There was a stormwater pond in Wisconsin that was infested. They ended up filling in the pond. Oh! There was also a small quarry in Virginia where they closed down the entire quarry for a couple of months and applied 174,000 gallons of potassium chloride solution to kill zebra mussels. So that worked too.” Sighs and groans filled the room.
McComas, an aquatic scientist with Blue Water Science, is known locally as an expert in aquatic invasive species – nonnative plants and animals that end up in our lakes and rivers and wreak havoc on local ecosystems. He’s worked frequently with Watershed Districts and lake associations to survey native and nonnative plants and develop early detection and rapid response plans for what to do if new invaders like zebra mussels are found. In Washington County, Eurasian watermilfoil has taken hold in 21 lakes, zebra mussels are in Forest Lake, White Bear Lake, and the St. Croix south of Stillwater, and flowering rush has become a problem along the shoreline of Forest Lake. Meanwhile, curly leaf pondweed and common carp (so common that we’ve put the word in their name) have become so prolific that the MN Department of Natural Resources is no longer even tracking them on its infested waters list.
Two years ago, the Minnesota Legislature earmarked special funding to give to counties for aquatic invasive prevention and education activities. During 2015, Washington County distributed its funds to lake associations and local units of government for a variety of projects, including education, signs and watercraft inspections at public boat launches, and treatment of invasive plants in several area lakes.
This year, Washington County will distribute $162,000 in funding to local partners for education, prevention and treatment efforts related to aquatic invasive species. Approximately half of the funding will be passed through to the Washington Conservation District for education and watercraft inspections across the county. The WCD will also be working with partners to develop early detection and rapid response plans for multiple water bodies across the county. Comfort Lake – Forest Lake Watershed District will receive funding to retrofit public boat launches on Forest Lake to include information kiosks, compost bins, and designated areas for boat cleaning. They will also be conducting watercraft inspections on Bone, Comfort, and Forest Lakes, and continuing to treat flowering rush on Forest Lake. The remainder of the aquatic invasives money will be given to Washington County Parks to make interpretive signs for Big Marine, Lake Elmo, Square, and St. Croix Bluffs Regional Parks, and to Big Marine, Clear, Demontreville/Olson, and Lake Elmo Lake Associations to treat Eurasian watermilfoil using a variety of approaches.
Invasive species come in all shapes and sizes and they aren’t limited to aquatic habitats. Some, like buckthorn and Japanese knotweed, take over woods and clearings, while others, like silver carp, live in the water. To be clear, invasive plants and animals are not inherently bad, but they can cause big problems when they gain a toehold in the local ecosystem and begin to crowd out others species. In England, for example, buckthorn is a well-behaved shrub, used frequently in gardens and yards. Here it spreads rapidly through woodlands, choking out native wildflowers and forming an impenetrable thicket. In Asia, river carp are part of the web of life, and provide a welcome source of food for millions of people. Here in the U.S., they can take over several river systems, out-competing native fish species and crashing wildly into anglers and boaters out on the water.
Given that eradicating invasive species is nearly impossible, education and prevention are still our best weapons in the fight to protect Minnesota’s waters. For all of us anxiously awaiting summer fishing, swimming and water recreation, that means remembering to clean and drain boats every time they come out of the water, only working with licensed contractors trained in AIS prevention when installing docks and lifts this spring, and always disposing of unwanted bait, including minnows, leeches, and worms, in the trash. For more information, visit: www.dnr.state.mn.us/invasives/aquatic.