Sea water provides the biggest habitat for living organisms. The sea water habitat occupies almost two-thirds of the surface of the earth and the majority of the earth’s producer and consumer organisms live in it. In the sea water community, algae or phytoplankton form the producers, zooplanktons are the primary consumers, and so on.

The various kinds of organisms which use sea water as habitat are Phytoplankton (Algae), Sea-plants, Zooplanktons (Protozoa), Snakes, Fishes, Crocodiles, Sea-Birds, Marine Mammals, Sea-turtles, and Crabs. Sea water provides a hospitable environment for the aquatic animals and plants.

There are some of the points that how sea water are uses as a habitat for organisms are as given below –

1. Sea water contains dissolved carbon dioxide gas. The aquatic plants (sea-plants) use this dissolved carbon dioxide for preparing food by the process of photosynthesis.
2. The sunlight can pass through the sea-water and becomes available to the sea plants for carrying out the building process of photosynthesis.
3. Sea water contains dissolved oxygen gas. The animals that breathe in water make use of this dissolved oxygen.
4. Sea water contains nitrogen, phosphorus, and many other nutrients that are utilized by the sea plants for their growth and development. Sea also provides sufficient food to the aquatic animals.
5. The temperature variations in the sea water are moderate and this factor is good for the organisms living in sea-water.
6. Sea water also provides various salts and minerals to the organisms living in the sea.