Eurasian watermilfoil (Myriophyllum spicatum) is an invasive exotic species with the potential to disrupt a lake’s ecological system and interfere with recreation. It is generally thought to have first entered lakes in North America in the 1940s. EWM is a concern because t rapidly colonizes lakes and spreads easily by fragmentation. This plant can grow up to the surface of the water and form extremely dense mats, inhibiting boating and swimming. It also crowds out some of the more ecologically beneficial aquatic plants. Once established, Eurasian watermilfoil is very difficult to remove and can be spread from lake to lake by boat traffic.