Dynamics and distribution of natural and human ... - Biogeosciences

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Feb 12, 2010 - Dynamics and distribution of natural and human-caused hypoxia. N. N. Rabalais1, R. J. Dıaz2, ... solved oxygen content have become a focal point of oceanic research. ..... Amazon and Orinoco plumes. The Bay of Bengal ...
Biogeosciences, 7, 585–619, 2010 www.biogeosciences.net/7/585/2010/ © Author(s) 2010. This work is distributed under the Creative Commons Attribution 3.0 License.

Biogeosciences

Dynamics and distribution of natural and human-caused hypoxia N. N. Rabalais1 , R. J. D´ıaz2 , L. A. Levin3 , R. E. Turner4 , D. Gilbert5 , and J. Zhang6 1 Louisiana

Universities Marine Consortium, Chauvin, Louisiana 70344, USA Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia 23062, USA 3 Integrative Oceanography Division, Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, California 92093-0218, USA 4 Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA 5 Institut Maurice-Lamontagne, Pˆ eches et Oc´eans Canada, 850 route de la mer, Mont-Joli, Qu´ebec, G5H 3Z4, Canada 6 State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 3663 Zhongshan Road North, Shanghai 200062, China 2 Virginia

Received: 31 August 2009 – Published in Biogeosciences Discuss.: 1 October 2009 Revised: 11 January 2010 – Accepted: 24 January 2010 – Published: 12 February 2010

Abstract. Water masses can become undersaturated with oxygen when natural processes alone or in combination with anthropogenic processes produce enough organic carbon that is aerobically decomposed faster than the rate of oxygen reaeration. The dominant natural processes usually involved are photosynthetic carbon production and microbial respiration. The re-supply rate is indirectly related to its isolation from the surface layer. Hypoxic water masses (