In the heart of North America lies one of the planet's greatest natural resources — the Great Lakes. The world’s largest freshwater ecosystem, the Great Lakes Watershed is home to roughly 35 million people and 3,500 species of plants and animals, including one-fifth of all of the fish species in North America. The Lakes’ more than 10,000 miles of shoreline encircle 90 percent of the United States’ freshwater and 18 percent of the world’s freshwater.So many and so much depends on the health of the Great Lakes, yet few people seem to know about the battle raging below the surface. For over a century, non-native species of plants, fish, invertebrates and bacteria have invaded the Great Lakes at an average of one every eight months. These invasive species are out-competing the Lakes’ native species so effectively that they’re literally transforming the ecosystem from top to bottom, threatening its ecological diversity and local economies. With more than 180 invasive species already in the Great Lakes, and new threats like the Asian carp knocking at the door, there has never been a better time for public education on invasive species. 