Chemical characterization of dissolved organic matter (DOM): A prerequisite for understanding UV-induced changes of DOM absorption properties and bioavailability

Sulzberger, Barbara; Durisch-Kaiser, Edith

doi:10.1007/s00027-008-8082-5

Cited by 184 publications

(111 citation statements)

References 247 publications

(552 reference statements)

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“…They suggest that the HMW-DOM is the more fresh material, whereas the low molecular weight (LMW) DOM is more diagenetically altered. The model theory was proven by several other studies (Sulzberger and Durisch-Kaiser, 2009, and references therein); however, there were other studies showing contradictory results (e.g. Rochelle-Newall et al, 2004;Rosenstock et al, 2005).…”

Section: What Happens To Hmw-doc Ter In the Baltic Sea?mentioning

confidence: 84%

Tracing inputs of terrestrial high molecular weight dissolved organic matter within the Baltic Sea ecosystem

et al. 2012

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Abstract. To test the hypothesis whether high molecular weight dissolved organic matter (HMW-DOM) in a high latitude marginal sea is dominated by terrestrial derived matter, 10 stations were sampled along the salinity gradient of the central and northern Baltic Sea and were analyzed for concentrations of dissolved organic carbon as well as δ 13 C values of HMW-DOM. Different end-member-mixing models were applied to quantify the influence of terrestrial DOM and to test for conservative versus non-conservative behavior of the terrestrial DOM in the different Baltic Sea basins. The share of terrestrial DOM to the total HMW-DOM was calculated for each station, ranging from 43 to 83 %. This shows the high influence of terrestrial DOM inputs for the Baltic Sea ecosystem. The data also suggest that terrestrial DOM reaching the open Baltic Sea is not subject to substantial removal anymore. However compared to riverine DOM concentrations, our results indicate that substantial amounts of HMW-DOM (> 50 %) seem to be removed near the coastline during estuarine mixing. A budget approach yielded residence times for terrestrial DOM of 2.8, 3.0, and 4.5 yr for the Bothnian Bay, the Bothnian Sea and the Baltic Proper.

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Section: What Happens To Hmw-doc Ter In the Baltic Sea?mentioning

confidence: 84%

Tracing inputs of terrestrial high molecular weight dissolved organic matter within the Baltic Sea ecosystem

et al. 2012

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“…4213 (Sulzberger and Durisch-Kaiser, 2009). To cover DOC pools of different lability two types of experiments with photochemical production of CH 3 I are performed.…”

Section: Stemmler Et Al: 1-d Modelling Of Methyl Iodidementioning

confidence: 99%

Numerical modelling of methyl iodide in the eastern tropical Atlantic

Stemmler¹,

Rothe

Hense³

et al. 2013

Biogeosciences

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Methyl iodide (CH₃I) is a volatile organic halogen compound that contributes significantly to the transport of iodine from the ocean to the atmosphere, where it plays an important role in tropospheric chemistry. CH₃I is naturally produced and occurs in the global ocean. The processes involved in the formation of CH₃I, however, are not fully understood. In fact, there is an ongoing debate whether production by phytoplankton or photochemical degradation of organic matter is the main source term. Here, both the biological and photochemical production mechanisms are considered in a biogeochemical module that is coupled to a one-dimensional water column model for the eastern tropical Atlantic. The model is able to reproduce observed subsurface maxima of CH₃I concentrations. But, the dominating source process cannot be clearly identified as subsurface maxima can occur due to both direct biological and photochemical production. However, good agreement between the observed and simulated difference between surface and subsurface methyl iodide concentrations is achieved only when direct biological production is taken into account. Production rates for the biological CH₃I source that were derived from published laboratory studies are shown to be inappropriate for explaining CH₃I concentrations in the eastern tropical Atlantic

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“…Once present in the water column and exposed to sunlight, however, allochthonous DOM can be photodegraded via the absorption of high-energy ultraviolet (UV) wavelengths (280-400 nm). Absorbed UV breaks down aromatic carbon rings, producing smaller, less aromatic DOM molecules (Bertilsson and Tranvik 2000;Osburn et al 2001;Sulzberger and Durisch-Kaiser 2009) that have lower molecular weights and are more bioavailable for bacterial consumption and decomposition (Wetzel et al 1995;Moran and Zepp 1997;Bertilsson and Tranvik 1998;Obernosterer and Benner 2004). Heterotrophic grazers subsequently consume bacteria, which shunts otherwise unavailable carbon, organic matter, and energy back into the aquatic food web via the microbial loop (Azam et al 1983).…”

Section: Introductionmentioning

confidence: 99%

Photodegraded dissolved organic matter from peak freshet river discharge as a substrate for bacterial production in a lake-rich great Arctic delta

Gareis

Lesack

2018

Arctic Science

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Lake-rich Arctic river deltas are recharged with terrigenous dissolved organic matter (DOM) during the yearly peak water period corresponding with the solstice (24 h day −1 solar irradiance). Bacteria-free DOM collected during peak Mackenzie River discharge was exposed to sunlight for up to 14 days in June 2010. As solar exposure increased, carbon and lignin concentrations declined (10% and 42%, respectively, after 14 days), as did DOM absorptivity (62% after 14 days), aromaticity, and molecular weight. Photochemical changes were on par with those normally observed in Mackenzie Delta lakes over the entire open-water season. When irradiated freshet DOM was provided as a substrate, no significant differences were observed in community-level metabolism among five bacterial communities from representative delta habitats. However, bacterial abundance was significantly greater when nonirradiated (0 day) rather than irradiated DOM (7 or 14 days) was provided, while cell-specific metabolic measures revealed that per-cell bacterial production and growth efficiency were significantly greater when communities were provided irradiated substrate. This complex response to rapid DOM photodegradation may result from the production of inhibitory reactive oxygen species (ROS), along with shifts in bacterial community composition to species that are better able to tolerate ROS, or metabolize the labile photodegraded DOM.Key words: circumpolar river delta, photodegradation, dissolved organic matter, bacterial metabolism, Mackenzie River.Résumé : Les deltas arctiques riches en lacs sont rechargés en matière organique dissoute (MOD) terrigène pendant la période annuelle de crue maximale correspondant au solstice (irradiance solaire 24 h jour −1 ). De la MOD sans bactéries collectée durant la pointe de crue du fleuve Mackenzie a été exposée à la lumière du soleil pendant 14 jours en juin 2010. À mesure que l'exposition solaire se prolongeait, les concentrations de carbone et lignine diminuaient (10 % et 42 % respectivement, après 14 jours), tout comme le pouvoir d'absorption de la MOD (62 % après 14 jours), son aromaticité et son poids moléculaire. Les changements photochimiques correspondaient à ceux normalement observés dans les lacs du delta du Mackenzie sur l'ensemble de la saison des eaux libres. Lorsque de la MOD de crue irradiée fut utilisée comme substrat, aucune différence significative n'a été observée quant au métabolisme au niveau de la communauté en comparant cinq communautés bactériennes issues d'habitats représentatifs du delta. Néanmoins, l'abondance de bactéries était considérablement plus grande lorsque de la For personal use only.MOD non irradiée (0 jour) a été fournie au lieu de la MOD irradiée (7 ou 14 jours), tandis que les mesures de l'activité métabolique spécifique aux cellules ont révélé que la production bactérienne par cellule et le rendement de croissance étaient considér-ablement plus élevés lorsque les communautés avaient accès au substrat irradié. Cette réaction complexe à la photodégradation...

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Chemical characterization of dissolved organic matter (DOM): A prerequisite for understanding UV-induced changes of DOM absorption properties and bioavailability

Cited by 184 publications

References 247 publications

Tracing inputs of terrestrial high molecular weight dissolved organic matter within the Baltic Sea ecosystem

Tracing inputs of terrestrial high molecular weight dissolved organic matter within the Baltic Sea ecosystem

Numerical modelling of methyl iodide in the eastern tropical Atlantic

Photodegraded dissolved organic matter from peak freshet river discharge as a substrate for bacterial production in a lake-rich great Arctic delta

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