Many wonder why we don't use the ocean as a resource for drinking water. Besides the fact that it doesn't taste very good, drinking saltwater is a bad idea because it causes dehydration. If you took a few gulps of ocean water, for example, your body would get rid of more water than you drank.
Oceans are the lifeblood of planet Earth and humankind. They flow over nearly three-quarters of our planet, and hold 97% of the planet's water. They produce more than half of the oxygen in the atmosphere, and absorb the most carbon from it.
The ocean plays a fundamental role in shaping the climate zones we see on land. Even areas hundreds of miles away from any coastline are still largely influenced by the global ocean system. While land areas and the atmosphere absorb some sunlight, the majority of the sun’s radiation is absorbed by the ocean. Particularly in the tropical waters around the equator, the ocean acts a as massive, heat-retaining solar panel. Earth’s atmosphere also plays a part in this process, helping to retain heat that would otherwise quickly radiate into space after sunset.
There are five main zones of the ocean. They are, the Sunlit Zone which gets the most sunlight making plants plentiful (0-656 ft), the Twilight Zone that contains jellyfish, octopuses, and squid (656-3,280 ft), the Midnight Zone which does not receive any sunlight, some animals in this zone lack eyes (3200-13,123 ft), Abyss where blind shrimp and hagfish strive (13,123-19,685 ft), and the Hadal Zone which is found in deep-water trenches and canyons (19,685-36,197 ft).
At sea level, the air that surrounds us presses down on our bodies at 14.5 pounds per square inch. You don't feel it because the fluids in your body are pushing outward with the same force. Dive down into the ocean even a few feet, though, and a noticeable change occurs. You can feel an increase of pressure on your eardrums. This is due to an increase in hydrostatic pressure, the force per unit area exerted by a liquid on an object. The temperature of the deep ocean drops gradually with depth. As saline water does not freeze until it reaches −2.3 °C (colder as depth and pressure increase) the temperature well below the surface is usually not far from zero degrees. The thermocline varies in depth.
The ocean provides a treasured source of recreation for humans. Besides the obvious that there is a great supply of fish, It is mined for minerals (salt, sand, gravel, and some manganese, copper, nickel, iron, and cobalt can be found in the deep sea) and drilled for crude oil. The ocean plays a critical role in removing carbon from the atmosphere and providing oxygen.