Eurasian watermilfoil (Myriophyllum Spicatum) is a plant native to Europe and Asia that was first documented in North America in the mid 1940s. Since its introduction, it has spread to more than 40 states in the US and to three Canadian provinces. Unfortunately, Eurasian watermilfoil has invaded many Northern Michigan lakes including Burt, Long, Paradise, and Walloon Lakes.
As Eurasian watermilfoil takes hold in a lake, it causes problems for the ecosystem and for recreation. It tolerates lower temperatures and starts earlier than other aquatic plants, quickly forming thick underwater stands of tangled stems and vast mats of vegetation at the water's surface. These dense weed beds at the surface can impede navigation – and no one likes to swim in areas thick with aquatic plants. The lake ecosystem suffers because Eurasian watermilfoil displaces and reduces native aquatic plant diversity, which is needed for a healthy fishery. Infestations can also impair water quality due to dissolved oxygen depletion as thick stands die and decay.
A key factor in the plant's success is its ability to reproduce through both stem fragmentation and underground runners. Eurasian watermilfoil spreads to other areas of a water body by fragmentation. A single stem fragment can take root and form a new colony. Locally, it spreads by spreading shoots underground.