|Freshwater | Marine | Pelagic | Benthic|
|Benthos | Nekton | Plankton | Semi-aquatic | Sessile | Terrestrial | Vagile|
The benthic zone is the name given to the bottom of the sea or ocean, and sometmes also a lake bottom. It represents the interface of water and substrate. Organisms that live here are known as benthos or benthic organisms. Some live on the surface (these are called epifauna and epiflora), and while others, known as infauna burrow in or live benath the surface of the mud or sand. Below the benthic level of water is the superficial layer of sand, mud, or other substrate. The nature of this layer has a great influence on the biological activity of the benthic zone. Examples of bottom layers include sand bottoms, rock outcrops, coral, and bay mud.
|Benthos | Littoral zone | Sublittoral zone | Bathyal zone | Abyssal zone | Hadal zone|