Book excerpt: The five Great Lakes, Lake Superior, Lake Michigan, Lake Huron, Lake Erie and Lake Ontario with their connecting waters are the world's largest freshwater system; about 20 per cent of all the fresh surface water on this planet. Each lake differs from the other and yet these connected lakes are one flowing system connected to the Atlantic through the St. Lawrence River. Unique ecosystems evolved in these lakes since the last Ice Age but in the last 200 years commercial fishing and the Lamprey Eel wiped out larger fish. Shipping on the Great Lakes from all parts of the world has brought exotic species that threaten to topple food pyramids. Pollution carried through the air and water damages life in and around these lakes. Through knowledge, and the democratic process, The Dynamic Great Lakes encourages us to appreciate and understand these lakes and to get involved in finding answers to their problems.