Saltwater Habitats

An ocean is a large body of salt water that supports marine life. A sea is a body of salt water smaller than an ocean. Plants that survive in oceans and seas are of two kinds: rooted plants and marine algae.

Rooted plants are those that live on the ocean or sea floor. However, they are found only on the floor of the shallow parts of these bodies of water because the sunlight that plants need for photosynthesis does not get to the deeper parts of oceans and seas. Sea grasses are among these plants.

Marine algae are the numerous, very tiny, and single-celled plants that contain chlorophyll, the green pigment that is found in all green plants. These plants float on the water surface where they can get lots of sunlight. They include diatoms, dinoflagellates, green and red algae, and phytoplankton.