Technically the Great Lakes hold one-fifth of the world's fresh surface water. ... One reason why the Great Lakes are so important is they harbor 20 percent of all the liquid water on Earth's surface. All the more reason to keep them pollution-free.
Explanation:
i know this doesnt really answer your question but im just hopeing itll help u a little.
In a time before railroads and highways, the Great Lakes and St. Lawrence River served as the primary transportation system. Many of North America's largest cities were established along the waterway as commerce flourished between their ports. Today, Great Lakes-Seaway shipping is equally important.
