| Zonation
The ocean can be divided into many zones. The ocean bottom is the benthic zone and the water itself (or the water column) is the pelagic zone. The neritic zone is that part of the pelagic zone that extends from the high tide line to an ocean bottom less than 600 feet deep. Water deeper than 600 feet is called the oceanic zone, which itself is divided on the basis of water depth into the epipelagic, mesopelagic, and bathypelagic zones. These zones roughly correspond to the three other zones divided on the basis of the amount of sunlight they receive. In the sunlit zone, enough light penetrates to support photosynthesis. Below that lies the twilight zone, where very small amounts of light penetrate. Ninety percent of the space in the ocean lies in the midnight zone, which is entirely devoid of light. (Click on the image to see a larger version.)
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