Profundal zone

Lake zones
Littoral zone
Limnetic zone
Profundal zone
Benthic zone
Lake stratification
Epilimnion
Metalimnion
Hypolimnion
Destratification
Lake types
Holomictic lake
   Monomictic lake
   Dimictic lake
   Polymictic lake
Meromictic lake
Amictic lake
Aquatic ecosystems
Wild fisheries

The profundal zone is a deep zone of an inland body of freestanding water, such as a lake or pond, located below the range of effective light penetration. This is typically below the thermocline, the vertical zone in the water through which temperature drops rapidly. The temperature difference may be large enough to hamper mixing with the littoral zone in some seasons which causes a decrease in oxygen concetrations. The profundal is often defined, in accordance with Thienemann (1925), as the deepest, vegetation-free, and muddy zone of the lacustrine benthal.[1] The profundal zone is often part of the aphotic zone.

The lack of light and oxygen in the profundal zone determines the type of biological community that can live in this region, which is distinctly different from the community in the overlying waters.[2] The profundal macrofauna is therefore characterized by physiological and behavioural adaptations to low oxygen concentration. Chironomidae and Oligochaetae often dominate the benthic fauna of the profundal zone because they possess hemoglobin like molecules to extract oxygen from poorly oxygenated water. [3]

See also

References

  1. Thienemann, A. 1925. Die Binnengewässer Mitteleuropas. Eine limnologiche Einführung. Binnengewässer 1. Stuttgart.
  2. Thienemann, A. 1920. Untersuchungen über die Beziehungen zwischen dem Sauerstoff gehalt des Wassers und der Zusammensetzung der Fauna in norddeutschen Seen. Archiv für Hydrobiologie 12.
  3. Int Panis, L; Goddeeris, B; Verheyen, R (1995). "On the relationship between vertical microdistribution and adaptations to oxygen stress in littoral Chironomidae (Diptera)". Hyrdobiologia 318 (1): 61–67.


This article is issued from Wikipedia - version of the Sunday, February 14, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.