Denitrification in coastal ecosystems: methods, environmental controls, and ecosystem level controls, a review
Cornwell, J.C.; Kemp, W.M.; Kana, T.M. (1999). Denitrification in coastal ecosystems: methods, environmental controls, and ecosystem level controls, a review. Aquat. Ecol. 33(1): 41-54. http://dx.doi.org/10.1023/A:1009921414151
In: Aquatic Ecology. Springer: Dordrecht; London; Boston. ISSN 1386-2588; e-ISSN 1573-5125, more
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| Keyword |
Chemical reactions > Denitrification
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| Author keywords |
denitrification; eutrophication; estuary; nitrogen; sediment-water exchange |
| Authors | | Top |
- Cornwell, J.C.
- Kemp, W.M.
- Kana, T.M.
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| Abstract |
In this review of sediment denitrification in estuaries and coastal ecosystems, we examine current denitrification measurement methodologies and the dominant biogeochemical controls on denitrification rates in coastal sediments. Integrated estimates of denitrification in coastal ecosystems are confounded by methodological difficulties, a lack of systematic understanding of the effects of changing environmental conditions, and inadequate attention to spatial and temporal variability to provide both seasonal and annual rates. Recent improvements in measurement techniques involving super(15)N techniques and direct N sub(2) concentration changes appear to provide realistic rates of sediment denitrification. Controlling factors in coastal systems include concentrations of water column NO- 3, overall rates of sediment carbon metabolism, overlying water oxygen concentrations, the depth of oxygen penetration, and the presence/absence of aquatic vegetation and macrofauna. In systems experiencing environmental change, either degradation or improvement, the importance of denitrification can change. With the eutrophication of the Chesapeake Bay, the overall rates of denitrification relative to N loading terms have decreased, with factors such as loss of benthic habitat via anoxia and loss of submerged aquatic vegetation driving such effects. |
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