The earth's oceans are home to thousands of species of marine life, from tiny plankton to enormous humpback whales. The Great Lakes' contain more than six thousand shipwrecks - important pieces of history kept preserved in their icy waters. These waters are also the heart of many human communities, from native communities that have depended on the ocean for centuries; to vacationers who use the water to dive, surf and fish; to scientists who study marine life. In this Into the Outdoors episode we see how National Marine Sanctuary designations across the country are protecting and preserving these precious natural resources.