Seawater makes up more than 70% of the earth, but we cannot drink seawater and only freshwater. You shouldn't drink seawater because it causes dehydration. When you drink seawater your body has to dispose more water than you drank and gets rid of all that extra salt. Then it causes you to be thirstier than you were before you drank the water.
The ocean is important to life on earth. The ocean covers most of the planet and contains 97% of the earths water. It also produces more than half of the oxygen for the atmosphere and absorbs carbon from the atmosphere.
The ocean current is related to the earth's climate. The currents are warmer near most coastlines and the equator and cold currents are near the poles.
In the ocean the deeper you get to the bottom of the floor the more dense it becomes and the colder it gets.
There are many resources that we use from the ocean. We mine from the ocean and get minerals like salt, sand, gravel, copper, nickel, iron, and cobalt. The ocean is also drilled for oil.