A new particulate Mn–Fe–P-shuttle at the redoxcline of anoxic basins

Dellwig, Olaf; Leipe, Thomas; März, Christian; Glockzin, Michael; Pollehne, Falk; Schnetger, Bernhard; Yakushev, E. V.; Böttcher, Michael E.; Brumsack, Hans‐Jürgen

doi:10.1016/j.gca.2010.09.017

Cited by 242 publications

(198 citation statements)

References 59 publications

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“…We note that the Fe/P ratios of the CDB solutions are close to 1.5 mol/mol (Online Resource 3), which is the Fe/P ratio of pure vivianite. In contrast, typical Fe/P ratios for sedimentary Fe-oxides are ∼10:1 mol/mol (Slomp et al 1996;Anschutz et al 1998;Dellwig et al 2010). The formation of vivianite thus likely explains the more than twofold increase in sediment P concentrations in the upper part of the organic-rich sediments at both sites (Fig.…”

Section: Phase C: Refreshening and Vivianite Formation In The Estuarymentioning

confidence: 92%

Holocene Refreshening and Reoxygenation of a Bothnian Sea Estuary Led to Enhanced Phosphorus Burial

Dijkstra

Krupinski

Yamane

et al. 2017

Estuaries and Coasts

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Salinity variations in restricted basins like the Baltic Sea can alter their vulnerability to hypoxia (i.e., bottom water oxygen concentrations <2 mg/l) and can affect the burial of phosphorus (P), a key nutrient for marine organisms. We combine porewater and solid-phase geochemistry, microanalysis of sieved sediments (including XRD and synchrotron-based XAS), and foraminiferal δ 18 O and δ 13 C analyses to reconstruct the bottom water salinity, redox conditions, and P burial in the Ångermanälven estuary, Bothnian Sea. Our sediment records were retrieved during the Integrated Ocean Drilling Program (IODP) Baltic Sea Paleoenvironment Expedition 347 in 2013. We demonstrate that bottom waters in the Ångermanälven estuary became anoxic upon the intrusion of seawater in the early Holocene, like in the central Bothnian Sea. The subsequent refreshening and reoxygenation, which was caused by gradual isostatic uplift, promoted P burial in the sediment in the form of Mn-rich vivianite. Vivianite authigenesis in the surface sediments of the more isolated part of the estuary ultimately ceased, likely due to continued refreshening and an associated decline in productivity and P supply to the sediment. The observed shifts in environmental conditions also created conditions for postdepositional formation of authigenic vivianite, and possibly apatite formation, at ∼8 m composite depth. These salinityrelated changes in redox conditions and P burial are highly relevant in light of current climate change. The results specifically highlight that increased freshwater input linked to global warming may enhance coastal P retention, thereby contributing to oligotrophication in both coastal and adjacent open waters.

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Section: Phase C: Refreshening and Vivianite Formation In The Estuarymentioning

confidence: 92%

Holocene Refreshening and Reoxygenation of a Bothnian Sea Estuary Led to Enhanced Phosphorus Burial

Dijkstra

Krupinski

Yamane

et al. 2017

Estuaries and Coasts

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“…Therefore, the lower boundary of the suboxic zone was defined to be at 90 m, where H 2 S concentrations sharply increased. The upper suboxic zone also showed a sharp peak in turbidity that is possibly caused by the precipitation of Fe and Mn oxides (Dellwig et al, 2010) or zero-valent sulfur (Kamyshny Jr. et al, 2013) and can be used as an indicator of the O 2 -H 2 S transition (Kamyshny Jr. et al, 2013). The anoxic zone extends from 90 m to the bottom and is characterized by the complete absence of O 2 and high concentrations of H 2 S and CH 4 .…”

Section: Physicochemical Parameters Of the Water Columnmentioning

confidence: 99%

Biomarkers in the stratified water column of the Landsort Deep (Baltic Sea)

et al. 2014

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Abstract. The water column of the Landsort Deep, central Baltic Sea, is stratified into an oxic, suboxic, and anoxic zone. This stratification controls the distributions of individual microbial communities and biogeochemical processes. In summer 2011, particulate organic matter was filtered from these zones using an in situ pump. Lipid biomarkers were extracted from the filters to establish water-column profiles of individual hydrocarbons, alcohols, phospholipid fatty acids, and bacteriohopanepolyols (BHPs). As a reference, a cyanobacterial bloom sampled in summer 2012 in the central Baltic Sea Gotland Deep was analyzed for BHPs. The biomarker data from the surface layer of the oxic zone showed major inputs from cyanobacteria, dinoflagellates, and ciliates, while the underlying cold winter water layer was characterized by a low diversity and abundance of organisms, with copepods as a major group. The suboxic zone supported bacterivorous ciliates, type I aerobic methanotrophic bacteria, sulfate-reducing bacteria, and, most likely, methanogenic archaea. In the anoxic zone, sulfate reducers and archaea were the dominating microorganisms as indicated by the presence of distinctive branched fatty acids: archaeol and pentamethylicosane (PMI) derivatives, respectively. Our study of in situ biomarkers in the Landsort Deep thus provided an integrated insight into the distribution of relevant compounds and describes useful tracers to reconstruct stratified water columns in the geological record.

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“…Scott and Passow, 2004); therefore they could also reduce the density of marine aggregates and 123 decrease their sinking velocity if the ratio of dense particles to TEP is too small (Azetsu-Scott and 124 Engel and Schartau, 1999;Mari et al, 2017). Mixed aggregates containing MnOx 125 and TEP have reported before for the GB and LD (Dellwig et al 2010;Glockzin et al 2014). 126…”

Section: Mnox Formation Mnox Particles Have Previously Been Observedmentioning

confidence: 98%

“…Additionally, MnOx aggregates may affect the cycling of particle-reactive elements like 130 phosphorous and trace metals via scavenging processes (Dellwig et al, 2010). To date, there are 131 no measurements of the density of MnOx-OM aggregates, their potential ballast effect of sinking 132 OM, or their effect on the flux of particle-reactive elements in the Baltic Sea.…”

Section: Passowmentioning

confidence: 99%

“…Then, in the 508 sulfidic waters, slow-sinking MnOx enriched in OM will be dissolved liberating the OM and 509 altering the vertical distribution and the flux of all associated particle elements (Glockzin et al, 510 2014). The precipitation of MnOx could be enhanced by the oxygenation of the otherwise anoxic 511 deep of the Baltic Sea caused by the 2014/105 MBI (Dellwig et al, 2018), those particles could 512 bind with phosphorous and trace metals trapping them in the redoxcline (Dellwig et al, 2010). 513…”

Section: Gb and The Ld 478mentioning

confidence: 99%

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Composition and Vertical Flux of Particulate Organic Matter to the Oxygen Minimum Zone of the Central Baltic Sea: Impact of a sporadic North Sea inflow

Cisternas-Novoa¹,

Moigne²,

Engel³

2018

Preprint

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Abstract. Sinking particles are the main form to transport photosynthetically fixed carbon from the euphotic zone to the ocean interior. Oxygen (O2) depletion may improve the efficiency of the biological carbon pump. However, how the lack of O2 mechanistically enhances particulate organic matter (POM) fluxes is not well understood. In the Baltic Sea, the Gotland Basin (GB) and the Landsort Deep (LD) exhibit permanent bottom-water hypoxia, this is on occasions alleviated by Major Baltic Inflow (MBI), such as the one that occurred in 2014/2015 which oxygenated the bottom waters of the GB (but not of the LD). Here, we investigate the distribution and fluxes of POM in the GB and the LD in June 2015 and how they were affected by the 2015 MBI. Fluxes and composition of sinking particles were different in the GB and the LD. In the GB, POC flux was 18&#8201;% lower at 40&#8201;m than at 180&#8201;m. Particulate nitrogen (PN) and Coomassie stainable particles (CSP) fluxes decreased with depth, and particulate organic phosphorous (POP), biogenic silicate (BSi), Chl a, and transparent exopolymeric particles (TEP) clearly peaked within the core of the oxygen minimum zone (OMZ), which coincided with a high flux of manganese oxide (MnOx)-like particles. Contrastingly, in the LD, POC, PN, and CSP fluxes decreased 28, 42 and 56&#8201;% respectively from 40 to 180&#8201;m. POP, BSi, and TEP fluxes, however, did not decrease with depth and only a slightly higher flux was measured at 110&#8201;m. MnOx-like particle flux was two orders of magnitude higher in the GB relative to the LD. MnOx-like particles formed after the inflow of oxygenated water into the deep GB may form aggregates with POM. Our results suggest, that when the deep waters of GB were oxygenated (2014/2015 North Sea inflow), not only transparent exopolymeric particles, as indicated previously, but also POC, POP, BSi, and Chl a may bind to MnOx-like particles. POM associated with MnOx-like particles may accumulate in the redoxcline, where they formed larger particles that eventually sank to the seafloor. We propose that this mechanism would alter the vertical distribution and the flux of POM, and it may contribute to the higher transfer efficiency of POC in the GB. This is consistent with the fact that the OM reaching the seafloor was fresher and less degraded in the GB than in the LD.

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A new particulate Mn–Fe–P-shuttle at the redoxcline of anoxic basins

Cited by 242 publications

References 59 publications

Holocene Refreshening and Reoxygenation of a Bothnian Sea Estuary Led to Enhanced Phosphorus Burial

Holocene Refreshening and Reoxygenation of a Bothnian Sea Estuary Led to Enhanced Phosphorus Burial

Biomarkers in the stratified water column of the Landsort Deep (Baltic Sea)

Composition and Vertical Flux of Particulate Organic Matter to the Oxygen Minimum Zone of the Central Baltic Sea: Impact of a sporadic North Sea inflow

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