The sea provides substantial supplies

A wide variety of organisms, including bacteria, protists, algae, plants, fungi, and animals, live in the sea, which offers a wide range of

marine habitats and ecosystems, ranging vertically from the sunlit surface and shoreline to the great depths and pressures of the cold,

dark abyssal zone, and in latitude from the cold waters under polar ice caps to the colourful diversity of coral reefs in tropical regions. Many of the major groups of organisms evolved in the sea and life may have started there.

The sea provides substantial supplies of food for humans, mainly fish, but also shellfish, mammals and seaweed, whether caught by fishermen or

farmed underwater. Other human uses of the sea include trade, travel, mineral extraction, power generation, warfare, and leisure activities such as

swimming, sailing, and scuba diving. Many of these activities create marine pollution. The sea has therefore been for humans an integral element throughout history and culture.