Great Lakes Ecosystem: The five Great Lakes represent the largest surface freshwater system in the world. They contain enough liquid to cover the entire United States with 7 feet of water! The State of Michigan alone has 3,300 miles of shoreline. Over 33 million people live within the Great Lakes watershed. Within this module learn how the Great Lakes were created, how water flows between the lakes, and see the Great Lakes food web come alive with animations and movies! Supports Ecosystems & Biodiversity Unit lessons 1-6, 8 and 9; and Water Quality Unit Lesson 9.