How are landforms effecting life below water

Vast in scope and size, there is only one true ocean on Earth. This connected body of water surrounds the continents and is divided into five major regions: the Pacific, Atlantic, Indian, Arctic, and Southern oceans. (The Black and Caspian Seas are enclosed by the landmass that makes up Europe and Asia.) Taken together, the oceans cover more than 70 percent of the Earth's surface and give the planet the appearance, from space, of a blue marble.