Overview: This episode focuses on the oceans, both in terms of their geography and their ecology. Discusses the various forms that the ocean floor takes including trenches, mountains and plains. From a life perspective this episode includes deep ocean creatures, plankton, anemone, crabs, rays, sharks, tuna, dolphins, narwhals, whales, walrus, seals, fish of all kinds, ducks, sea dragons, cuttlefish. From a specific habitat perspective many types including kelp forest, coral atolls, underwater deserts, the Sargasso sea, the gulf stream and the grand banks. The effect commercial fishing is having is called into question.