Throughout its long history, the ocean has provided Earth with numerous services, including climate regulation, trade and transport, and food production. In addition, the ocean provides an important habitat for a variety of animal species.
The ocean, a body of salt water, spans about 71 percent of Earth’s surface and is called the “world ocean” or simply “ocean.” Many scientists have divided the ocean into five major regions: Pacific, Atlantic, Indian, Southern, and Arctic.
These boundaries may help identify specific seas that have historical or political significance, but they do not reflect water properties, ocean currents, or biological populations.
One example is the Sargasso Sea, which lies within the ocean but is not bounded by land, so it is considered a sea rather than an ocean.
Another important characteristic of the ocean is its color, which depends on the concentration of green pigment – chlorophyll – in phytoplankton. Chlorophyll is a naturally occurring green pigment that absorbs light, and when it is present, the ocean appears to be a shade of green.
In contrast, other substances that are dissolved in the oceans can also absorb light and make the water appear bluer. Examples of this are sulfate and ammonium ions.
Some of these substances are very toxic to human health. In addition, they can harm marine animals and their ecosystems.
The ocean is the largest of all water bodies on Earth, and it is also the most diverse. It is home to a large number of species, some of which are so small they cannot be seen with the naked eye.
Among these creatures are plankton, which are tiny organisms that are the basis for photosynthesis. Phytoplankton can live in water that is either clear or very dark, depending on its pH and salt content.
These organisms are very useful to humans and other marine animals because they can provide food, oxygen, and shelter in the ocean’s deep water. They can also help to regulate the planet’s temperature, and they are also a vital part of the ocean’s chemical balance.
Although most of the ocean is relatively shallow, there are a few very deep seas, including the Gulf of Mexico, which has an average depth of 7,686 meters. This is more than a mile below the average depth of the entire ocean, but it’s still significantly deeper than the average depth of all the other seas combined.