From the seashore to the deepest depths, oceans are home to some of the most diverse life on Earth. There are big animals and little ones; long and short ones, multicolored and drab ones, and those that just sit while others that never stop swimming. There are even some organisms that light up.
Oceanographers divide the ocean into five broad zones according to how far down sunlight penetrates:
The Sunlit Zone (Epipelagic)
The top layer of the ocean where enough sunlight penetrates for plants to carry on photosynthesis.
The Twilight Zone (Mesopelagica )
Where some light penetrates, but not enough for plants to grow. The Midnight Zone (Bathypelagic)
The deep ocean layer where no light penetrates.
The abyssal zone
The pitch-black bottom layer of the ocean; the water here is almost freezing and its pressure is immense.
The Hadal Zone
The waters found in the ocean's deepest trenches.
Plants are found only in the sunlit zone where there is enough light for photosynthesis, however, animals are found at all depths of the oceans though their numbers are greater near the surface where food is plentiful. Still, over 90 percent of all species dwell on the ocean bottom where a single rock can be home to over ten major groups such as corals, mollusks and sponges.
(Every color in the background of this page corresponds with each zone)
The Five Oceanic Zones