Describe various vertical zones of the ocean.
The vertical zones of the ocean can be determined by the availability of light for photosynthesis. The lighted upper 200 meters form the photic or euphotic zone. The next zone, up to the depth of 2000 meters, gets less light which is insufficient for photosynthesis. This layer is called an aphotic zone. Below 2000 meters is the area of perpetual darkness, called the abyssal zone.
