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Sources, turnover and bioavailability of dissolved organic nitrogen (DON) in the Colne estuary, UK

Agedah, EC and Binalaiyifa, HE and Ball, AS and Nedwell, DB (2009) 'Sources, turnover and bioavailability of dissolved organic nitrogen (DON) in the Colne estuary, UK.' Marine Ecology Progress Series, 382. pp. 23-33. ISSN 0171-8630

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The significance of dissolved organic nitrogen (DON) as a eutrophication pressure in the Colne estuary, eastern England, was Studied. DON comprised a significant proportion (19%) of the annual total dissolved N load to the Colne estuary, DON concentrations in the upper Colne estuary correlated seasonally with river flow; in contrast, DON inputs from the Colchester sewage treatment works (STW) were constant seasonally, and during summer exceeded the input of DON from the river. Bioassays showed that only 2.2 to 5.2% of DON were bioavailable at any given time, and bioavailability was significantly lower in STW DON than in fluvial DON. Degradation of DON within the estuarine water column followed first-order kinetics and was very slow (mean 0.4%) of DON removed d(-1)) although removal by the bottom sediments was faster (mean 3% DON d(-1)). The low bioavailability and slow breakdown rate of DON, compared to the typical freshwater flushing time of water in the estuary, meant that the DON load, though considerable, did not represent a significant eutrophication pressure within the estuary, Most. DON was degraded outside the estuary in the coastal zone.

Item Type: Article
Uncontrolled Keywords: Dissolved organic nitrogen; DON; Bioavailability; Estuarine N loads
Subjects: Q Science > QH Natural history > QH301 Biology
Divisions: Faculty of Science and Health
Faculty of Science and Health > Life Sciences, School of
SWORD Depositor: Elements
Depositing User: Elements
Date Deposited: 06 Oct 2011 15:06
Last Modified: 06 Jan 2022 13:20

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