Monitoring efforts are continuing at both the US Fish and Wildlife Service and the Upper Mississippi River National Fish and Wildlife Refuge to help curb two invasive species. The water hyacinth and water lettuce were discovered in the Upper Mississippi on the shores of Lake Onalaska in October of this year. These two invasive species grow very rapidly and if left unchecked can end up taking over large areas in only one growing season, potentially causing damage to the ecosystem.
These plants are native to South America, but have been sold for use in aquariums and backyard ponds. Parties responsible for releasing these species into the wildlife refuge have been issued violation notices, and businesses from which they potentially bought these species have destroyed all of their water hyacinth and water lettuce supplies.
With the mild winter we have been enduring, it's important to note that these species may become more difficult to clean out, given that they have more opportunity to grow.
"If it freezes, we have a much better chance of the plants dying off," says Upper Mississippi National Fish and Wildlife Refuge Visitor Services Manager Hallie Rasmussen. "...but when we have a mild winter, we need to make sure that we are monitoring and staying on top of it, to make sure that there aren't any more [invasive] plants in the water.
This find in October is the third time an invasive species has been discovered in the Upper Mississippi, and the public is being urged to stay vigilant in preventing incidents like this in the future.
"We ask that the public never release anything into the river," says Rasmussen. "...especially plants, invasive species, things like that [...] If folks see this, or if they see anything that looks weird, [they should] notify us."
If you notice any water hyacinth, water lettuce, or anything unusual in and around the Mississippi River, contact the US Fish and Wildlife Service at 1-608-779-2399