Pelagic Zone - Organisation of the Marine Ecosystem

The waters contained in the sea basin, constitute the pelagic zone which is divided into

1. The neritic zone situated above the sublittoral zone or the continental shelf starting from the edge of the littoral sea and extending up to the edge of the continental shelf, to a depth of 200 m. Beyond this is the
2. Deep, open sea of the oceanic zone which is divided on the basis of light penetration as discussed in earlier sections the physicochemical property of light of the oceans.

The upper illuminated zone of the open ocean is also called epipelagic zone. So the euphotic pelagic ocean is named a epipelagic one. The aphotic pelagic province .has been divided into the following three horizontal zones: mesopelagic, bathypelagic and the abyssopelagic zone. There is no light in the bathypelagic and abyssopelagic zones. The mesopelagic zone is comparatively less dark but light is not sufficient to carry out photosynthesis.