The zone at the edge of a lake or ocean or in aquatic habitat which is alternatively exposed to air is the littoral zone, hence, light is also available and immersed in water. This coastal zone is rich producers from surface to bottom, with a large number of brown and red alga attached at the zone. Different zones is an aquatic ecosystem.
Any zone of water in a sea or lake that is neither close to bottom nor the shore is pelagic zone.
It is the bottom part of the water body (aphotic zone) where light is not available and is dark. Microorganisms and benthic organisms are found in this zone. It is referred as benthic zone.
Lentic zone refers to standing or relativelly still water in an equatic ecosystem.