Marine life can be divided into three categories depending how they live.
Plankton are plants and animals that live near or on the surface of the ocean.
Some can swim a little, but they mostly rely n current, waves, and tides to float to their destinations. In one way or another, most marine life depends on plankton as a food source. Phytoplankton, or plant plankton, need to be near light for photosynthesis to take place. Animal plankton, zooplankton, eat the Phytoplankton. They are found near the Phytoplankton which rely on spikes, oil and air-filled floats to maintain buoyancy.