Denitrification in sediments of the River Colne estuary, England

Dong, Lixin; Thornton, Daniel C. O.; Nedwell, David B.; Underwood, Graham J. C.

doi:10.3354/meps203109

Cited by 124 publications

(160 citation statements)

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“…In full agreement with this concept, Dong et al (2000) showed experimentally that Dn was independent of the concentration of NO in the wa-…”

Section: Discussionmentioning

confidence: 59%

“…In the light of these results, Jeppesen et al (1998) and Van Luijn et al (1995) proposed that invasion of benthic microalgae in lakes after a shift to a clear-water state would promote the loss of nitrogen via coupled nitrification-denitrification and thus accelerate the process of recovery from eutrophication-a statement that apparently contradicts the hypothesis of Henriksen and Kemp (1988). However, several field studies have indicated that light-induced stimulation is not a general phenomenon (Rysgaard et al 1995;Cabrita and Brotas 2000;Sundbäck and Miles 2000), and it has been suggested that stimulation of coupled nitrification-denitrification in light only occurs when competition between algae and nitrifiers and denitrifiers for dissolved inorganic nitrogen (DIN) is not limiting the bacterial processes (Rysgaard et al 1995;Dong et al 2000). Yet, the overall effect of benthic microalgae on coupled nitrification remains unclear.…”

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confidence: 99%

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Coupled nitrification‐denitrification in autotrophic and heterotrophic estuarine sediments: On the influence of benthic microalgae

Risgaard‐Petersen¹

2003

Limnology & Oceanography

200

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Field data obtained from 18 European estuaries using the isotope pairing technique were analyzed for trends in relationship between activity of benthic microalgae and coupled nitrification-denitrification. Kruskal-Wallis tests and analyses of covariance performed on the field dataset showed strong statistical evidence for the hypothesis that sediments colonized by microalgae whose activity exceeds community respiration display lower rates of coupled nitrification-denitrification than do heterotrophic sediments. In fully heterotrophic sediments, 90% of the measurements fell within the range 0-92 mol N m Ϫ2 h Ϫ1 with a median of 20.3 mol N m Ϫ2 h Ϫ1. In highly autotrophic sediments, 90% of the measurements fell within the range 0-34 mol N m Ϫ2 h Ϫ1 , and the median was 4.2 mol N m Ϫ2 h Ϫ1 . The hypothesis was tested experimentally using 15 N and microsensor (NO ) techniques in prepared Ϫ 3 microcosms with and without algal activity. The results of the experimental studies were consistent with the hypothesis derived from the field data analysis. For the 15 N study, coupled nitrification-denitrification in alga-colonized sediments was between 4 and 51% of the activity in sediments without algae activity, depending on the N load. For the microsensor study, there was no indication of net NO production in alga-colonized sediments before furthermore showed that compared to heterotrophic sediment, the presence of active microalgae might reduce the population of nitrifying bacteria capable of having an active metabolism. These bacterial populations could display diurnal variations in activity correlated with the diurnal variations in O 2 penetration depth, however. The results showed that induction of nitrogen limitation of the nitrifying bacteria population is a major controlling mechanism of coupled nitrification-denitrification in alga-colonized sediments.

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“…In full agreement with this concept, Dong et al (2000) showed experimentally that Dn was independent of the concentration of NO in the wa-…”

Section: Discussionmentioning

confidence: 59%

mentioning

confidence: 99%

Coupled nitrification‐denitrification in autotrophic and heterotrophic estuarine sediments: On the influence of benthic microalgae

Risgaard‐Petersen¹

2003

Limnology & Oceanography

200

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“…Point Clear is close to the mouth of the estuary, has the highest salinity of the three sites (30-34‰), and has a MPB dominated by diatoms. Sediments at all sites are cohesive, with a high proportion of clay particles (Ͻ63 m size) and water content between 60% and 80%, and support abundant microphytobenthic biofilms at the sediment surface during periods of low tide (see Dong et al 2000;Thornton et al 2002;Perkins et al 2002 for further details). Alresford Creek and Hythe were sampled on 15 July 1999, Alresford Creek and Point Clear on 22 July 1999, and Alresford Creek and Hythe on 22 and 29 March 2000.…”

Section: Sampling and Methodsmentioning

confidence: 99%

Patterns in microphytobenthic primary productivity: Species‐specific variation inmigratory rhythms and photosynthetic efficiency in mixed‐species biofilms

Underwood

Perkins

Consalvey

et al. 2005

Limnology & Oceanography

125

151

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The importance of temporal changes in the vertical distribution of microphytobenthic algae on the overall functioning of intertidal biofilms were investigated with low-temperature scanning electron microscopy and high-resolution single-cell fluorescence imaging of photosystem II efficiency (estimated by the fluorescence parameter F / Ј q F ) in intact cores maintained in tidal mesocosms. Early morning biofilms consisted of smaller naviculoid and Ј m nitzschioid taxa or euglenoid species. By midday, Gyrosigma balticum and Pleurosigma angulatum were dominant. Some taxa (e.g., Plagiotropis vitrea) disappeared from surface layers after midday. Species composition continued to change toward the end of the photoperiod, with G. balticum dominating in diatom-rich biofilms. In Euglena-rich biofilms, initial dense surface films of euglenids became progressively dominated by smaller diatoms. F /F (mea-Ј Ј q m sured at a photosynthetically active photon flux density (PPFD) of 220 mol m Ϫ2 s Ϫ1) of individual cells of all taxa declined significantly after midday, but increased toward dusk. There were significant differences in F /F between Ј Ј q m species, particularly after midday. F /F versus irradiance curves and relative electron transport rate (rETR max ) Ј Ј q m showed higher efficiencies and rETR max for euglenids, whereas G. balticum, Nitzschia dubia, and small Nitzschia sp. were shade-adapted with low values of F /F m Ј, rETR max , and E sat . G. balticum, P. vitrea, and N. dubia showed Ј q rapid vertical migration away from the surface with increasing irradiance. Euglenids, P. angulatum, and N. dubia exhibited their highest rETR max values at midday. E sat for algal cells was between 500 and 600 mol m Ϫ2 s Ϫ1 , except for N. dubia and small Nitzschia sp., which had an E sat of 300 mol m Ϫ2 s Ϫ1. Differences in behavioral and photophysiological traits between microphytobenthic taxa could be a form of niche separation and need to be incorporated into conceptual models of daily patterns of production in intertidal biofilms.

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“…An increase in temperature for instance can directly result in an increase in the rate of denitrification, but, can also increase the nitrification rate which then additionally enhances the supply of nitrate (Seitzinger, 1988). A seasonal variation in denitrification can be observed frequently and is reported for Baltic Sea sediments (Tuominen et al, 1998;Sundbäck et al, 2000;Hietanen and Kuparinen 2008) as well as for other regions (Nowicki et al, 1997;Cabrita and Brotas, 2000;Dong et al, 2000). For the Gulf of Finland, Hietanen and Kuparinen (2008) found a seasonal cycle with higher rates during autumn and early winter, whereas Tuominen et al (1998) measured the highest rates in late summer and early autumn.…”

Section: Factors Controlling the Rate Of Denitrification In Baltic Sementioning

confidence: 98%

Denitrification in sediments as a major nitrogen sink in the Baltic Sea: an extrapolation using sediment characteristics

et al. 2010

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Abstract.Rates of denitrification in sediments were measured with the isotope pairing technique at different sites in the southern and central Baltic Sea. The rates varied between 0.5 µmol N m −2 h −1 in sands and 28.7 µmol N m −2 h −1 in muddy sediments and showed a good correlation to the organic carbon contents of the surface sediments. N-removal rates via sedimentary denitrification were estimated for the entire Baltic Sea calculating sediment specific denitrification rates and interpolating them to the whole Baltic Sea area. Another approach was carried out by using the relationship between the organic carbon content and the rate of denitrification. The N-removal by denitrification in sediments varied between 426-652 kt N a −1 , which is around 48-73% of the external N inputs delivered via rivers, coastal point sources, and atmospheric deposition. Moreover, an expansion of the anoxic bottom areas was considered under the assumption of a rising oxycline from 100 to 80 m water depth. This leads to an increase of the area with anoxic conditions and an overall decrease in sedimentary denitrification by 14%. Overall, we show here that this type of data extrapolation is a powerful tool to estimate the nitrogen losses for a whole coastal sea and may be applicable to other coastal regions and enclosed seas.

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Denitrification in sediments of the River Colne estuary, England

Cited by 124 publications

References 40 publications

Coupled nitrification‐denitrification in autotrophic and heterotrophic estuarine sediments: On the influence of benthic microalgae

Coupled nitrification‐denitrification in autotrophic and heterotrophic estuarine sediments: On the influence of benthic microalgae

Patterns in microphytobenthic primary productivity: Species‐specific variation inmigratory rhythms and photosynthetic efficiency in mixed‐species biofilms

Denitrification in sediments as a major nitrogen sink in the Baltic Sea: an extrapolation using sediment characteristics

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