Earth is often called the Blue Planet.
When you look at earth its easy to see why -- it's mostly blue, because it is mostly covered by water.
Ocean covers more than 70% of earth's surface. Amazingly more than 95 percent of the underwater world in the sea is still unexplored.
There is one ocean called World Ocean: but in that ocean there are different basins. For example, the Arctic Ocean is a basin and so is the Atlantic Ocean!
Oceans are large saltwater bodies of water, in fact oceans holds 97 percent of all water on earth! The ocean is extremely important to life on earth. It regulates earth's climate and half of earth's oxygen - what we breathe - is produced in the ocean!
Actually, the ocean supports the life of nearly 50 percent of all species on earth and helps sustain that life providing 20 percent of the animal protein and five percent of the total protein in the human diet.
And, oceans are very important to cultures and economies around the world. For example, one of every six jobs in the United States is marine-related and over one-third of the U.S. Gross National Product originates in coastal areas.
Around the world, ocean is key to transportation, recreation and its resources may hold the cures to many diseases!
Within their vast expanse, oceans support tremendous biodiversity. Scientists to date have catalogued nearly 1/4-million species in the ocean, but they estimate that up to 10 million more have yet to be discovered!
Oceans are all-important in regulating global climate. Tiny ocean plants, called phytoplankton, serve as as the planet's lungs, absorbing enormous amounts of carbon dioxide and making it into oxygen and biomass.
This photosynthesis takes up about 50 million tons of carbon per year, about as much as is taken up by plants on land -- and this photosynthesis makes 1/2 the oxygen in our atmosphere, the oxygen we breathe. Each year the ocean the ocean takes up 1/4 of the carbon we humans emit to the atmosphere.
Without the ocean, life on Earth as we know it simply would not be able to exist.
Enlarge to see ocean habitats - click on the image or click here