Importance of the Ocean

Since ancient times, the ocean has served as a source of such food as fish and shellfish. Rock strata beneath the ocean floor are an important source of petroleum and natural gas. Seawater is a source of sodium chloride and other salts. Seawater from which salt has been removed is used for drinking and for agricultural and industrial purposes.

The ocean plays an important role in the water cycle, the constant movement of water from the atmosphere to the earth's surface and back. The ocean and its currents influence the climate of many areas.

A wide variety of organisms, including algae, jellyfish, lobsters, fish, sea turtles, and whales, live in the ocean. Many of these organisms are threatened by pollution. Among the causes of this pollution are the discharge of municipal and industrial wastes, and the accidental spilling of oil from tankers and offshore oil rigs. A number of laws and international agreements ban or restrict the disposal of various pollutants into the ocean.