Saltwater Habitats

Saltwater habitats, also called marine habitats, are environments made up of large amounts of salt. Oceans and seas are the two major habitats of this type.

An ocean is the largest body of salt water. The world’s five major oceans make up about one-third of Earth’s surface. The largest ocean is the Pacific Ocean.

Another major saltwater habitat is the sea, a body of water that is smaller than the ocean. A sea is surrounded by land masses and is connected to an ocean. The largest sea on Earth is the South China Sea (West Philippine Sea).

The temperature in oceans and seas changes very slowly. This protects marine organisms against sudden changes in temperature that can cause them stress. About 14,000 species of fish live in saltwater habitats, along with other marine creatures that range from the huge whales, sharks, and dolphins to the microscopic algae, bacteria, and fungi. All these coexist with other marine animals that live on the bottom or floor of the deep sea or ocean. These marine creatures include corals, clams, sea urchins, and bottom-dwelling fishes.