As spring-like temperatures move into the area Saturday, it's a reminder that boating season will be here soon, and Watonwan County’s office of land management wants to remind everyone of best practices before the weather warms.
While Watonwan County is already afflicted with some milder types of aquatic invasive species, like curlyleaf pondweed and purple loosestrife, it’s paramount to keep out more pernicious strains, like zebra mussels and starry stonewort. There are many ways of preventing these miasmic influences from polluting the county’s waterways.
For example, “clean off your boat,” and lift and drain it in that area; do not wait to return to home base, said Heidi Rudolph, assistant land management director. All vegetation also should be cleaned off the boat on-site.
Don’t take bait from lake to lake, either, added Dave Haler, land management director. Invasive species like these can live for two weeks after contact.
Furthermore, keep all drain plugs out while traveling, Haler noted. Finally, dry items such as docks, lifts, and swim rafts for at least 21 days before placing equipment into another body of water.
Curlyleaf pondweed is already in Kansas Lake, St. James Lake, Long Lake, and Butterfield Lake, Haler said. Boat (propellors) “get full of it, it’s hard on recreation.”
Curlyleaf pondweed is a rooted submerged plant that quickly forms dense mats at the water surfaces of lakes and rivers in late spring and early summer, and in late fall and early winter, it sprouts from rhizomes and turions (overwintering buds), shading out later growing native plants, according to the University of Minnesota. It displaces native plant communities, and decay can deplete oxygen levels, leading to fish kills and negative outcomes for other aquatic life.
It’s tolerant of low light, and it grows throughout winter, according to the University of Minnesota. It forms floating mats in littoral areas in lakes, ponds, and moderately-flowing rivers, and it may be mistaken for largeleaf pondweed or claspingleaf pondweed.
Purple loosestrife is in ditches, slews, and lakes, Rudolph said. “It chokes out the natives, and it’s just kind of a hassle.”
It’s an invasive perennial plant spreading rapidly across North America, and the thick strands are deleterious to native plants; plus, it attenuates food and shelter, and nesting areas for wildlife, according to the University of Minnesota. Mature plants have multiple stems--dead stems stand throughout spring--they grow three-seven feet in height, they possess downy, smooth-edged leaves, the stem has ridges, and the flower has several pink-purple petals.
“We can’t eradicate the (aquatic invasive species) we do have here right now,” Haler said. “It’s just about control and stopping them where they are.”
Still, these are relatively harmless compared to a dastardly species like zebra mussels, Rudolph said. “They take over the lake, they can get into motors.”
In addition, they’re like “little razors in the water,” Haler said. “They can cut you.”
Zebra mussels are small, fingernail-sized animals that attach to solid surfaces in water, according to the Minnesota Department of Natural Resources. Zebra mussels can be a costly problem for cities and power plants when they clog water intakes.
In addition, they eat tiny food particles that they filter out of the water, which can reduce available food for larval fish and other animals, and cause aquatic vegetation to grow as a result of increased water clarity, according to the DNR. Zebra mussels can also attach to and smother native mussels.
In August, starry stonewort was discovered in Lake Koronis, “which really alarmed me, because a lot of people around here go up there,” Haler said. Like other invasive species, starry stonewort grows into dense mats that can cover the surface of shallow waters; this chokes out other plants and creates a wall between fish and their spawning grounds.
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