Extension has always worked to manage invasive species in agriculture. But in the late 1980s, Extension also led the way in addressing threats to Minnesota's water recreation and economy from aquatic invasive species. Educators moved fast to get information out to the public about zebra mussels, which can clog pipes and cost millions of dollars for clean-up. Educators also helped Minnesotans curtail other major threats--purple loosestrife, Eurasian water milfoil, curly leaf pondweed--saving the state from untold numbers of dollars in clean-up and landowners from heavy loss to property values. Today, Extension educates about the benefits of prevention, containment and minimizing impacts to keep new species from spreading.