Carbon dioxide and methane emissions from estuaries
Abril, G.; Borges, A.V. (2004). Carbon dioxide and methane emissions from estuaries, in: Tremblay, A. et al. (Ed.) Greenhouse gases emissions from natural environments and hydroelectric reservoirs: fluxes and processes. Environmental Science Series, : pp. 187-207
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| Abstract |
Carbon dioxide and methane emissions from estuaries are reviewed in relationwith biogeochemical processes and carbon cycling. In estuaries, carbondioxide and methane emissions show a large spatial and temporalvariability, which results from a complex interaction of river carbon inputs,sedimentation and resuspension processes, microbial processes in watersand sediments, tidal exchanges with marshes and flats and gas exchangewith the atmosphere. The net mineralization of land-derived organic carbonleads to high CO2 atmospheric emissions (10-1000 mmol.m-2.d-1 i.e.44-4400 mg.m-2.d-1) from inner estuarine waters and tidal flats and marshsediments. Estuarine plumes at sea are sites of intense primary productionand show large seasonal variations of pCO2 from undersaturation to oversaturation;on an annual basis, some plumes behave as net sinks of atmosphericCO2 and some others as net sources; CO2 atmospheric fluxes inplumes are usually one order of magnitude lower than in inner estuaries.Methane emissions to the atmosphere are moderate in estuaries (0.02-0.5 mmol.m-2.d-1 i.e. 0.32-8 mg.m-2.d-1), except in vegetated tidal flats andmarshes, particularly those at freshwater sites, where sediments may beCH4-saturated. CH4 emissions from subtidal estuarine waters are the resultof lateral inputs from river and marshes followed by physical ventilation,rather than intense in-situ production in the sediments, where oxic andsuboxic conditions dominate. Microbial oxidation significantly reduces theCH4 emissions at low salinity (<10) only. |
| Datasets (2) |
- Borges, A.V.; Frankignoulle, M.; Chemical Oceanograpy Unit - Université de Liège; (2004): Continuous acquisition of inorganic and organic carbon and associated parameters at the station Ste Anna, Antwerp, meer
- Frankignoulle, M.; Borges, A.V.; Chemical Oceanograpy Unit - Université de Liège; (2007): EUROTROPH project dataset: Nutrients Cycling and the Trophic Status of Coastal Ecosystems, meer
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