The benthic zone is the lowest level of a body of water, such as an ocean or a lake. It is inhabited mostly by organisms that tolerate cool temperatures and low oxygen levels, called benthos or benthic organisms. The profundal, limnetic, and littoral zones can be found above the benthic zone. No light other than bioluminescence is found in the benthic zone; it is part of the aphotic zone. Below the benthic level of water is the superficial layer of the soil lining the given body of water. The nature of this soil layer has a great influence on the biological activity of the benthic zone. Example contact soil layers are sand bottoms, rock outcrops, coral and bay mud.

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Ecology | Aquatic biomes