Environment Planet Earth What's So Great About the Great Lakes? By Melissa Breyer Melissa Breyer Editorial Director Hunter College F.I.T., State University of New York Cornell University Melissa Breyer is Treehugger’s editorial director. She is a sustainability expert and author whose work has been published by the New York Times and National Geographic, among others. Learn about our editorial process Updated February 22, 2019 This image was gathered by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite in August 2010. The pale blue and green swirls near the coasts are likely caused by algae blooms. (Photo: NASA Goddard Photo and Video/flickr). Share Twitter Pinterest Email Planet Earth Outdoors Weather Conservation The latest report card assessing the well-being of the Great Lakes is out, and the findings are mixed. The analysis performed by the International Joint Commission looked at chemical, biological and physical characteristics to determine the lakes' health. For much of the 20th century, the Great Lakes suffered abuse courtesy of industrial waste and household sewage, as well as a number of deleterious invasive species, especially mussels. The most recent report has found that although efforts to heal these magnificent bodies of water have helped reduce toxic pollution and have impeded the progress of invasive species, new problems have arisen. Some toxins have decreased, while new chemicals have turned up; algae blooms have made a return appearance, and rising temperatures are lowering water levels. It could be worse, but it isn’t fantastic. And why does it matter? Because the Great Lakes are great — spectacular, in fact. Aside from the point that more than 35 million people live in the Great Lakes Basin and depend upon its natural resources, consider the following: The Great Lakes Basin Ecosystem is the largest body of freshwater in the world. It covers 95,000 square miles and includes 5,000 tributaries with a drainage area of 288,000 square miles. Traveling its 9,000 miles of shoreline would be the equivalent of three trips between California and the East Coast. The Great Lakes support a variety of fish and wildlife species of concern. Fish species of special interest, according to the U.S. Fish and Wildlife Service, include lake trout, lake sturgeon, lake whitefish, walleye, landlocked Atlantic salmon and associated forage fish species. The Great Lakes watershed provides habitat for the gray wolf, Canada lynx, little brown bat, beaver, moose, river otter, and coyote, and other important North American animals. For the bird lovers — not to mention the birds themselves — the area provides crucial breeding, feeding, resting areas, and migration corridors for many birds including the bald eagle, Northern harrier, common loon, double-crested cormorant, common tern, bobolink, least bittern, common merganser and the endangered Kirtland's warbler. And perhaps most remarkable of all, according to the EPA, together the lakes are home to 84 percent of North America's supply of surface fresh water, and 21 percent of the world's supply of surface fresh water. And to put that number in perspective: nearly 1.2 billion people in the world don't have access to water. The United Nation says that water scarcity is among the biggest hurdles the world will face in the 21st century. We’ve got 6 quadrillion gallons of fresh water in the Great Lakes. That's 6,000,000,000,000,000 gallons! We need to cherish that.