Our Beautiful Oceans
And everything inside of them
The ocean is the body of salt water which covers approximately 70.8% of the surface of Earth and
contains 97% of Earth's water. Separate names are used to identify five different areas of
the ocean: Pacific (the largest) Atlantic, Indian, Southern (Antarctic), and Arctic (the smallest).
Seawater covers approximately 361,000,000 km2 (139,000,000 sq mi) of the planet. The ocean is the
principal component of Earth's hydrosphere, and therefore integral to life on Earth. Acting as a huge
heat reservoir, the ocean influences climate and weather patterns, the carbon cycle, and the water
cycle.Marine life, 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. Marine life in part
shape and protect shorelines, and some marine organisms even help create new land (e.g. coral building
reefs). Most life forms evolved initially in marine habitats. By volume, oceans provide about 90% of
the living space on the planet.The earliest vertebrates appeared in the form of fish, which live
exclusively in water. Some of these evolved into amphibians, which spend portions of their lives in
water and portions on land. Other fish evolved into land mammals and subsequently returned to the
ocean as seals, dolphins, or whales. Plant forms such as kelp and other algae grow in the water and
are the basis for some underwater ecosystems. Plankton forms the general foundation of the ocean food
chain, particularly phytoplankton which are key primary producers.