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