Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Oxygen-Minimum Zone

  • Daniele L. PintiEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_5164-2





The oxygen-minimum zone or OMZ is the zone in a body of water (lakes, oceans, etc.) in which the oxygen saturation is minimum and thus redox conditions are hypoxic (O2 concentration <75 μmol/L) or anoxic (O2 concentration <1 μmol/L).


In terrestrial oceans, the oxygen-minimum zone develops between 200 and 1,000 m below the sea level. The development of the OMZ in oceans is mainly related to the consumption of oxygen by aerobic bacteria degrading dead organisms descending through the water column from the above oxygenated ocean layer. At depths >1,000 m, the ocean is again oxygenated because the bottom currents bring cold, oxygen-rich, polar waters. On the continental platform, sediments in contact with the OMZ are also in anoxic conditions, allowing the preservation of buried organic matter. OMZ plays a key role in regulating the ecological community structure of the global ocean. In this zone important metabolic...


Redox zonation Anoxia Archean ocean Oxygenation of the Earth Anaerobia Nitrogen cycle Denitrification 
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References and Further Reading

  1. Kamykowski D, Zentara SJ (1990) Hypoxia in the world ocean as recorded in the historical data set. Deep-Sea Res 37:1861–1874ADSCrossRefGoogle Scholar
  2. Sigman DM, Kash KL, Casciotti KL (2009) Ocean process tracers: nitrogen isotopes in the ocean. In: Steele JH, Turekian KK, Thorpe SA (eds) Encyclopedia of ocean science, 2nd edn. Elsevier, AmsterdamGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.GEOTOP Research Center for Geochemistry and GeodynamicsUniversité du Québec à MontréalMontréalCanada