Uptake of dissolved inorganic nitrogen in turbid, tidal estuaries
In: Marine Ecology Progress Series. Inter-Research: Oldendorf/Luhe. ISSN 0171-8630; e-ISSN 1616-1599, more | |
Keywords | ANE, France, Gironde Estuary [Marine Regions]; ANE, France, Pays de Loire, Loire Estuary [Marine Regions]; ANE, Germany, Ems Estuary [Marine Regions]; ANE, Netherlands, Rhine estuary [Marine Regions]; ANE, Netherlands, Westerschelde [Marine Regions]; ANE, Portugal, Douro Estuary [Marine Regions] Marine/Coastal; Brackish water; Fresh water | Author keywords | nitrogen uptake; nitrogen turnover; ammonium; nitrate; estuary;heterotrophy |
Abstract | Ammonium and nitrate uptake was measured in 6 European tidal estuaries (Ems, Rhine, Scheldt, Loire, Gironde and Douro) using 15N-tracer techniques. Uptake rates of ammonium and nitrate ranged from 0.005 to 1.56 µmol N l-1h-1 and 0.00025 to 0.25 µmol N l-1 h-1, respectively, and differed significantly between and within estuaries. Analysis of nitrogen uptake using the relative preferential index (RPI) indicated ammonium to be the preferred substrate. The turnover times of particulate nitrogen (0.7 to 31 d) and dissolved ammonium (0.1 to 27 d) were similar to or shorter than estuarine-water residence times, whereas turnover times of dissolved nitrate (19 to 2160 d) were longer than residence times. Assimilation of nitrate in the water column of estuaries consequently does not influence its distribution, and most nitrate entering or produced in estuaries flushes through unless significant denitrification and/or burial in the sediment occur. As ammonium and particulate nitrogen are efficiently recycled, most allochthonous organic matter is extensively microbially modified before export, burial, or consumption by higher trophic levels. |
Datasets (2) | - Frankignoulle, M.; Borges, A.V.; Chemical Oceanograpy Unit - Université de Liège; (2004): BIOGEST project dataset: Biogas Transfer in Estuaries, more
- Middelburg J. 1998: Publication data from Jack Middelburg for BIOGEST (particulate del13C, del15N, POC, PON, DOC, N2O and nitrogen uptake data). Netherlands Institute of Ecology; Centre for Estuarine and Marine Ecology, Netherlands. Metadata available at http://mda.nioo.knaw.nl/imis.php?module=dataset&dasid=1811, more
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