The pelagic zone comprises the water column of the open ocean and can be further differentiated into areas by depth. In deep water, the pelagic zone at certain occasions is known as the open-ocean zone and can be contrasted with water, which is close to the continental shelf of the coast.
Or it can be said, that coastal water not near the bottom is still regarded to be in the pelagic zone. The tunas, sharks, and big marine mammals, like dolphins and whales travel in these waters.
At the bottom you have the producers aka auto trophic livings (which use inorganic compounds to grow, produce energy, matter and so on..). These organisms would be plants, Cyrano bacteria, over all any organisms that do photosynthesis.
