Over 180 invasive species have entered the Great Lakes and their wetlands. Pictured is purple loosestrife, a European plant that will take over a wetland like the Mafia takes over a neighborhood.
Native species do not stand a chance against it. Wetlands serve as natural filters for pollutants and help prevent floods. The species of plants that evolved around the Great Lakes serve an important purpose in their ecology.
Read more on this topic in my book, The Dynamic Great Lakes.