Marine life, or sea life or ocean life, is the plants, animals and other organisms that live in the salt water of the sea or ocean, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. Marine organisms, mostly microorganisms, produce oxygen and sequester carbon. Shorelines are in part shaped and protected by marine life, and some marine organisms even help create new land. The term marine comes from the Latin mare, meaning sea or ocean.