epipelagic zone

/ ĕp′ə-pə-lăj′ĭk /

1. The uppermost part of the oceanic zone, lying above the mesopelagic zone , that receives enough sunlight to allow photosynthesis. The epipelagic zone can reach depths of about 200 m (656 ft) in tropical and subtropical latitudes and about 100 m (328 ft) in higher latitudes or where upwellings or other conditions cause turbidity. In general, the clearer the water, the deeper the epipelagic layer at that location. The epipelagic zone is more abundant in marine life than the lower zones; in particular, phytoplankton cannot live at any lower depths.
2. ◆ The epipelagic zone is divided into the neritic epipelagic zone , which lies over the continental shelf, and the oceanic epipelagic zone , which is the upper layer of water in the part of the open ocean that is not over the continental shelf.