Properties of fluorescent dissolved organic matter in the Gironde Estuary

Huguet, Arnaud; Vacher, Lilian; Relexans, Stéphane; Saubusse, Sylvain; Froidefond, Jean-Marie; Parlanti, E.

doi:10.1016/j.orggeochem.2009.03.002

Cited by 1,404 publications

(915 citation statements)

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“…26 In the Gironde estuary (France), the DOC showed non-conservative behavior and consumption of DOC in winter in the region of average salinity, and production in that region during the summer. 32 Similar results were found in the estuaries of the Tamar (England), Sado (Portugal) and Ems (The Netherlands), where DOC showed the same non-conservative behavior, with production during the summer. 50,52 To explain these deviations, the authors attributed the increased concentrations of DOC to desorption of organic compounds from particulate matter in the maximum turbidity zone, or the resuspension of bottom sediment.…”

supporting

confidence: 70%

“…Previous studies have also found that the humic fraction of CDOM increases during the rainy period in regions directly influenced by fluvial discharges, reflecting the larger continental input from allochthonous DOM during this period. 32,48 The relationships obtained between fluorescence intensity and salinity are illustrated in Figures 3 and 4. The samples collected in July (Figure 3) showed almost identical changes for peaks II and III, with an increase of the intensity of fluorescence in the salinity range from 0 to 3, after which the intensity decreased.…”

Section: Variation Of Fluorescence Intensity and Doc Along The Estuarymentioning

confidence: 99%

“…Another contributing factor is that the sources and sinks of fluorescent material are not necessarily the same as those of the total dissolved organic matter. 32,[54][55] Ratios between the intensities of the different peaks have been used to accompany changes in the relative amounts of different fluorophores. 32 Peak I is representative of protein-like compounds, and therefore reflects aquatic biological activity.…”

Section: Variation Of Fluorescence Intensity and Doc Along The Estuarymentioning

confidence: 99%

“…28,29 Fluorescence spectroscopy has been extensively used in studies of the estuarine mixing process, for characterization and differentiation of masses of water. 26,[30][31][32][33] In the present work, fluorescence spectroscopy was used to accompany the evolution of DOM during the mixing of fluvial and marine waters in the Piauí River estuary, which is a tropical estuary situated in the State of Sergipe, northeast Brazil. The technique enabled the separation and quantification of the fluorescent DOM originating from terrestrial material (humic substances) and that produced in the local environment from the degradation of natural biologic material.…”

mentioning

confidence: 99%

“…The organic compounds released then result in an increase of fluorescence intensity, relative to that which would be expected in the presence of dilution alone. 32,50 In estuarine regions, DOM is influenced by a variety of physical processes, and both conservative and nonconservative behavior has been observed. 26,28,32,49 In estuaries along the southwest coast of Florida, located in the Ten Thousands Island and Whitewaste Bay, DOC showed a conservative behavior during the dry period in the years 2001 and 2002.…”

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confidence: 99%

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Characterization of dissolved organic matter in the Piauí river estuary, Northeast Brazil

Costa¹,

Passos²,

Garcia³

et al. 2011

J. Braz. Chem. Soc.

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A espectroscopia de fluorescência e o carbono orgânico dissolvido (COD) foram utilizados para caracterização da matéria orgânica dissolvida (MOD) no estuário do Rio Piauí, um estuário tropical situado no Estado de Sergipe, nordeste do Brasil. As intensidades de fluorescência foram maiores no período chuvoso e menores no período seco, evidenciando que a variabilidade das propriedades fluorescentes da MOD é ditada, principalmente, pela descarga fluvial e pelo processo de diluição no estuário. No período chuvoso, os compostos tipo triptofano e húmicos predominaram na composição da MOD, enquanto no período seco ocorreu um aumento significativo dos constituintes tipo proteínas. As relações das intensidades de fluorescência com a salinidade sugerem um comportamento não conservativo para a MOD fluorescente. O COD mostrou um comportamento conservativo no período seco e não conservativo no período chuvoso, com produção de COD na parte superior do estuário. A complexação da MOD com o Cu(II), estudada usando a técnica de supressão da fluorescência, evidenciou o potencial de complexação dos fluoróforos tipo proteínas, tripofano e húmico.Fluorescence spectroscopy and dissolved organic carbon (DOC) measurements were used to characterize the dissolved organic matter (DOM) in the Piauí River estuary, a tropical estuary situated in the State of Sergipe, Northeast Brazil. Fluorescence intensities were greater during the rainy period than the dry period, demonstrating that variability in the fluorescence properties of the DOM was determined mainly by the fluvial discharge and the dilution processes occurring in the estuary. During the rainy period, tryptophan-like and humic substances were the main components of the DOM, while during the dry period there was a significant increase of proteinlike constituents. Relationships identified between fluorescence intensities and salinity were indicative of non-conservative behavior of the fluorescent DOM. DOC showed behavior that was conservative during the dry period, and non-conservative during the rainy period, with production of DOC in the upper reaches of the estuary. The complexation of DOM with Cu(II), studied using the fluorescence suppression technique, showed the complexation potentials of protein, tryptophan and humic type fluorophores.Keywords: natural organic matter, Piauí River, estuary, fluorescence IntroductionDissolved organic matter (DOM) is a complex heterogeneous mixture of macromolecules formed by the decomposition of biological material derived from animals or plants. DOM represents one of the main reservoirs of carbon on the Earth's surface, and exhibits a variety of ecologically and geochemically important properties including the ability to absorb light, bind with trace metals and organic pollutants, adsorb substances onto its surface and undergo aggregation, as well as photochemical reactivity. [1][2][3] The DOM present in natural waters can have either autochtone or allochtone origins. Allochtone organic matter is introduced into aquatic systems by leaching from ...

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supporting

confidence: 70%

Section: Variation Of Fluorescence Intensity and Doc Along The Estuarymentioning

confidence: 99%

Section: Variation Of Fluorescence Intensity and Doc Along The Estuarymentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Characterization of dissolved organic matter in the Piauí river estuary, Northeast Brazil

Costa¹,

Passos²,

Garcia³

et al. 2011

J. Braz. Chem. Soc.

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Variations in high‐latitude riverine fluorescent dissolved organic matter: A comparison of large Arctic rivers

2013

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[1] Given the pace of climate change, it is important to better understand dissolved organic matter (DOM) storage and cycling in high-latitude rivers and its subsequent export to the Arctic Ocean. To address this concern, excitation/emission matrix spectroscopy and parallel factor analysis (PARAFAC) coupled with optical indices were used to characterize the optical properties of fluorescent DOM (FDOM) and colored DOM (CDOM) in five large Arctic rivers over two seasonal cycles. Five PARAFAC components were identified and proved useful indicators for the quantitative and qualitative descriptions of DOM sources and modification processes within Arctic watersheds. In comparing Pan-Arctic relationships between the optical properties and chemical properties of DOM, three components traced terrigenous biomarkers and two components are introduced as potential indicators for microbial processing. Conversely, no individual PARAFAC component could be directly linked to a specific plant source or river and simpler absorbance indices (i.e., a 350 ) proved to be better suited to quantify dissolved organic carbon and lignin phenol concentrations. Differences in FDOM character between the rivers could be explained by general watershed characteristics, including vegetation, topography, and hydrology. Based on these differences, the influence of coniferous vegetation on DOM character is most apparent in the Lena and Yenisei Rivers and bog-derived FDOM sources are more important in the Ob River. This study illustrates how increased hydrological connectivity in the Ob catchment and the abundance of lakes within the Mackenzie watershed may influence FDOM concentrations and the microbial processing of DOM within these watersheds.

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Chromophoric and fluorescent dissolved organic matter in and above the oxygen minimum zone off Peru

Loginova

Thomsen

Engel

2016

J. Geophys. Res. Oceans

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As a result of nutrient upwelling, the Peruvian coastal system is one of the most productive regions in the ocean. Sluggish ventilation of intermediate waters, characteristic for the Eastern Tropical South Pacific (ETSP) and microbial degradation of a high organic matter load promotes deoxygenation at depth. Dissolved organic matter (DOM) plays a key role in microbial respiration and carbon cycling, but little is known on DOM distribution and cycling in the ETSP. DOM optical properties give important insights on DOM sources, structure and biogeochemical reactivity. Here, we present data and a conceptual view on distribution and cycling of chromophoric (CDOM) and fluorescent (FDOM) DOM in and above the oxygen minimum zone (OMZ) off Peru. Five fluorescent components were identified during PARAFAC analysis. Highest intensities of CDOM and of the amino acid‐like fluorescent component (C3) occurred above the OMZ and coincided with maximum chl a concentrations, suggesting phytoplankton productivity as major source. High intensities of a marine humic‐like fluorescent component (C1), observed in subsurface waters, indicated in situ microbial reworking of DOM. FDOM release from inner shelf sediment was determined by seawater analysis and continuous glider sensor measurement and included a humic‐like component (C2) with a signature typical for terrestrially derived humic acids. Upwelling supplied humic‐like substances to the euphotic zone. Photo‐reactions were likely involved in the production of a humic‐like fluorescent component (C5). Our data show that variable biological and physical processes need to be considered for understanding DOM cycling in a highly dynamic coastal upwelling system like the ETSP off Peru.

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Properties of fluorescent dissolved organic matter in the Gironde Estuary

Cited by 1,404 publications

References 67 publications

Characterization of dissolved organic matter in the Piauí river estuary, Northeast Brazil

Characterization of dissolved organic matter in the Piauí river estuary, Northeast Brazil

Variations in high‐latitude riverine fluorescent dissolved organic matter: A comparison of large Arctic rivers

Chromophoric and fluorescent dissolved organic matter in and above the oxygen minimum zone off Peru

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