Microbial Mn(IV) and Fe(III) reduction in northern Barents Sea sediments under different conditions of ice cover and organic carbon deposition

Nickel, Maren; Vandieken, Verona; Brüchert, Volker; Jørgensen, Bo Barker

doi:10.1016/j.dsr2.2008.05.003

Cited by 52 publications

(32 citation statements)

References 43 publications

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“…Even if our calculations only approximate the true contribution of metals to carbon mineralization, the results indicate that bacterial sulfate reduction is by far the major anaerobic carbon mineralization pathway in these sediments. The prevalence of bacterial sulfate reduction in anaerobic carbon mineralization agrees with results of Vandieken et al (2006) and Nickel et al (2008) from the northern Barents Sea where icefree stations support higher rates of sulfate reduction than the more permanently ice-covered stations, reflecting lower carbon export production.…”

Section: Coupled Terminal Electron-accepting Processessupporting

confidence: 80%

“…Marine organic carbon is derived from open-water production during the ice-free months, export of ice algae, and new production in polynyas (Sakshaug et al, 2004;Nitishinsky et al 2007). Generally, marine productivity in the Laptev Sea is low and controlled by the nutrients derived from Atlantic water, but spring outflow from the Lena River provides an additional temporary land-derived nutrient source (Pivovarov et al, 1999;Sakshaug et al, 2004;Nitishinsky et al, 2007;Bourgeois et al, 2017) during late spring ice melt (Raymond et al, 2007). Terrestrially derived nutrients can also directly affect marine productivity by new production, or indirectly due to plankton production from remineralized, terrestrially derived dissolved organic carbon and particulate organic carbon Tesi et al, 2017).…”

Section: Marine Versus Terrestrial Organic Matter Contributionmentioning

confidence: 99%

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Carbon mineralization in Laptev and East Siberian sea shelf and slope sediment

et al. 2018

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Abstract. The Siberian Arctic Sea shelf and slope is a key region for the degradation of terrestrial organic material transported from the organic-carbon-rich permafrost regions of Siberia. We report on sediment carbon mineralization rates based on O 2 microelectrode profiling; intact sediment core incubations; 35 S-sulfate tracer experiments; pore-water dissolved inorganic carbon (DIC); δ 13 C DIC ; and iron, manganese, and ammonium concentrations from 20 shelf and slope stations. This data set provides a spatial overview of sediment carbon mineralization rates and pathways over large parts of the outer Laptev and East Siberian Arctic shelf and slope and allows us to assess degradation rates and efficiency of carbon burial in these sediments. Rates of oxygen uptake and iron and manganese reduction were comparable to temperate shelf and slope environments, but bacterial sulfate reduction rates were comparatively low. In the topmost 50 cm of sediment, aerobic carbon mineralization dominated degradation and comprised on average 84 % of the depthintegrated carbon mineralization. Oxygen uptake rates and anaerobic carbon mineralization rates were higher in the eastern East Siberian Sea shelf compared to the Laptev Sea shelf. DIC / NH + 4 ratios in pore waters and the stable carbon isotope composition of remineralized DIC indicated that the degraded organic matter on the Siberian shelf and slope was a mixture of marine and terrestrial organic matter. Based on dual end-member calculations, the terrestrial organic carbon contribution varied between 32 and 36 %, with a higher contribution in the Laptev Sea than in the East Siberian Sea. Extrapolation of the measured degradation rates using isotope end-member apportionment over the outer shelf of the Laptev and East Siberian seas suggests that about 16 Tg C yr −1 is respired in the outer shelf seafloor sediment. Of the organic matter buried below the oxygen penetration depth, between 0.6 and 1.3 Tg C yr −1 is degraded by anaerobic processes, with a terrestrial organic carbon contribution ranging between 0.3 and 0.5 Tg yr −1 .

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Section: Coupled Terminal Electron-accepting Processessupporting

confidence: 80%

Section: Marine Versus Terrestrial Organic Matter Contributionmentioning

confidence: 99%

Carbon mineralization in Laptev and East Siberian sea shelf and slope sediment

et al. 2018

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“…For that reason, only two studies, from the Skagerrak and Black Sea, are available for direct comparison on the partitioning of Mn reduction. The process has also been indicated to be of importance in the Panama Basin based on diagenetic modeling (Aller, 1990) and at some Arctic shelf sites where it was, however, not quantified separately from Fe reduction (Vandieken et al, 2006;Nickel et al, 2008). Mn reduction was responsible for over 90 % of total C org oxidation at 600 m depth in the Skagerrak (Canfield et al, 1993b), and accounted for 13-45 % of anaerobic C org oxidation in the Black Sea shelf sites at 60-130 m of water depth .…”

Section: Org Oxidation Dominated By Manganese Reduction In the Ubmentioning

confidence: 99%

“…The significance of dissimilatory iron reduction for C org oxidation is well established in the sediments of various continental margins and coastal wetlands Thamdrup and Canfield, 1996;Jensen et al, 2003;Kostka et al, 2002a, b;Vandieken et al, 2006;Hyun et al, 2007Hyun et al, , 2009b. However, only a few locations such as the Panama Basin (Aller, 1990), the coastal Norwegian trough in Skagerrak and an adjacent fjord (Canfield et al, 1993a, b;Vandieken et al, 2014), the Black Sea shelf , and the continental shelf of the northern Barents Sea (Vandieken et al, 2006;Nickel et al, 2008) are known where microbial manganese reduction significantly contributes to carbon mineralization.…”

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confidence: 99%

Manganese and iron reduction dominate organic carbon oxidation in surface sediments of the deep Ulleung Basin, East Sea

et al. 2017

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Abstract. Rates and pathways of benthic organic carbon (C org ) oxidation were investigated in surface sediments of the Ulleung Basin (UB) characterized by high C org contents (> 2.5 %, dry wt.) and very high contents of Mn oxides (> 200 µmol cm −3 ) and Fe oxides (up to 100 µmol cm −3 ). The combination of geochemical analyses and independently executed metabolic rate measurements revealed that Mn and Fe reduction were the dominant C org oxidation pathways in the center of the UB, comprising 45 and 20 % of total C org oxidation, respectively. By contrast, sulfate reduction was the dominant C org oxidation pathway, accounting for 50 % of total C org mineralization in sediments of the continental slope. The relative significance of each C org oxidation pathway matched the depth distribution of the respective electron acceptors. The relative importance of Mn reduction for C org oxidation displays saturation kinetics with respect to Mn oxide content with a low half-saturation value of 8.6 µmol cm −3 , which further implies that Mn reduction can be a dominant C org oxidation process even in sediments with lower MnO 2 content as known from several other locations. This is the first report of a high contribution of manganese reduction to C org oxidation in offshore sediments on the Asian margin. The high manganese oxide content in the surface sediment in the central UB was maintained by an extreme degree of recycling, with each Mn atom on average being reoxidized ∼ 3800 times before permanent burial. This is the highest degree of recycling so far reported for Mn-rich sediments, and it appears linked to the high benthic mineralization rates resulting from the high C org content that indicate the UB as a biogeochemical hotspot for turnover of organic matter and nutrient regeneration.

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“…Therefore, the concentration of iron in the water depends on the pH value. For instance, when the pH value is higher than 8.5, the equilibrium concentration of Fe 2þ is lower than 0.27 mg/L, as determined by the Fe(OH) 2 ; while at low pH conditions, the anaerobic environment will promote the transformation from Fe 3þ to Fe 2þ in sediment [28,29].…”

Section: Iron Release Of Jinpen Reservoirmentioning

confidence: 98%

Characteristics of Pollutants Released from Reservoir Sediments

Xia

Zhou

et al. 2016

The Handbook of Environmental Chemistry

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Nitrogen is not only a basic constituent element of life, but it is also one of the key elements causing eutrophication. It has an important effect on nutritional status and water quality in lakes and reservoirs. Inorganic nitrogen, including ammonia (NH 4 þ ) and nitrate (NO 3 À ), often occurs following nitrification and denitrification reactions in a multiphase interface with the change of dissolved oxygen (DO) and redox. In addition, the extent of heavy metals is diffused from sediments to overlying water. It may cause potential harm to the water quality of the reservoir. This chapter is separated into two parts: (1) The release of nitrogen and phosphorus from sediment is investigated in typical Chinese reservoirs; (2) The release of metals from sediment is investigated in typical Chinese reservoirs.

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Microbial Mn(IV) and Fe(III) reduction in northern Barents Sea sediments under different conditions of ice cover and organic carbon deposition

Cited by 52 publications

References 43 publications

Carbon mineralization in Laptev and East Siberian sea shelf and slope sediment

Carbon mineralization in Laptev and East Siberian sea shelf and slope sediment

Manganese and iron reduction dominate organic carbon oxidation in surface sediments of the deep Ulleung Basin, East Sea

Characteristics of Pollutants Released from Reservoir Sediments

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