The Digital Fish Library

This division of the epipelagic zone incorporates sunlit waters that are outside the continental shelf, and includes the photic zone which can reach depths of about 200 m in clear tropical and subtropical latitudes, and about 100 m in higher latitudes or where upwellings or other conditions cause turbidity. These waters have enough illumination for photosynthesis and are more abundant in marine life than the lower zones primarily because phytoplankton cannot live at any lower depths. Fish that inhabit these waters are called open ocean or offshore pelagic fish.