Sulphidic Mediterranean surface waters during Pliocene sapropel formation

Passier, Hilde F.; Bosch, Hendrik-Jan; Nijenhuis, Ivar A; Lourens, Lucas Joost; Böttcher, Michael E.; Leenders, Anke; Damsté, Jaap S. Sinninghe; Lange, Gert J. de; Leeuw, J.W. de

doi:10.1038/16441

Cited by 169 publications

(66 citation statements)

References 27 publications

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“…Observed abundances of oxiphilic benthic foraminifera support such a trend of bottom water oxygen with water depth and indicate that bottom water anoxia during S1 times may have been spatially restricted and/or of an intermittent nature, particularly at shallower sites (Casford et al, 2003). The Pliocene sapropel has an age of 2.943 Ma (Lourens et al, 1996;Passier et al, 1999a) and is laminated and extremely organic-rich (up to 27 wt% C org ). The presence of speci¢c molecular fossils and the trace metal, Fe and S geochemistry of this sapropel (Bosch et al, 1998;Passier et al, 1999a) provide evidence for its deposition under a euxinic (i.e.…”

Section: Methodsmentioning

confidence: 86%

“…The Pliocene sapropel has an age of 2.943 Ma (Lourens et al, 1996;Passier et al, 1999a) and is laminated and extremely organic-rich (up to 27 wt% C org ). The presence of speci¢c molecular fossils and the trace metal, Fe and S geochemistry of this sapropel (Bosch et al, 1998;Passier et al, 1999a) provide evidence for its deposition under a euxinic (i.e. sul¢de-rich) water column that reached into the photic zone.…”

Section: Methodsmentioning

confidence: 99%

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Controls on phosphorus regeneration and burial during formation of eastern Mediterranean sapropels

2004

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The carbon (C) and phosphorus (P) geochemistry of sapropels from four sites in the eastern Mediterranean Sea was determined to obtain more insight into the role of differences in sediment accumulation rates and bottom water anoxia on P regeneration and burial in sediments. Sediment C org /P org (with org = organic) ratios above Redfield indicate enhanced regeneration of P relative to C from organic matter during formation of the most recent sapropel S1 and a Pliocene sapropel (ODP-site 969E; i-282c). Release of P from Fe-oxides was relatively unimportant. Increased burial of Ca-P (authigenic carbonate fluorapatite and/or biogenic hydroxyapatite) occurred but was of minor importance compared to the enhanced P release from organic matter. For sapropel S1, C org /P org and C org /P reac , (with reac = reactive, defined as the sum of organic, Fe-bound, authigenic and biogenic Ca-P) ratios decreased with increasing sedimentation rate and oxygen exposure and decreasing water depth. Whether the water column in the deep basin was dysoxic/semi-euxinic (S1) or euxinic (Pliocene) does not appear to affect the estimated burial efficiencies of P org and P reac . Enhanced C org burial under the euxinic water column explains the much higher C org /P org and C org /P reac ratios in the Pliocene sapropel (on average V2860 and V760, respectively) compared to sapropel S1 (on average V530 and V160, respectively). ß

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Section: Methodsmentioning

confidence: 86%

Section: Methodsmentioning

confidence: 99%

Controls on phosphorus regeneration and burial during formation of eastern Mediterranean sapropels

2004

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“…Isorenieratene and its derivatives are preserved in sediments dating back to the Ordovician . Their occurrence in some eastern Mediterranean sapropels of Pliocene age has been used to infer the existence of sulphidic/anoxic conditions in the photic zone of the water column (Passier et al, 1999;Menzel et al, 2002). The sedimentary record of isorenieratene in Black Sea sediments has been used to argue that the photosynthethic green sulphur bacteria have been active in the Black Sea for the last 6200 years and that penetration of the photic zone by anaerobic waters is a natural phenomenon (Sinninghe Damsté et al, 1993).…”

Section: Biochemical Indicators: Pigments and Lipid Biomarkersmentioning

confidence: 99%

Historical records of coastal eutrophication-induced hypoxia

Jorissen²,

et al. 2009

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Abstract. Under certain conditions, sediment cores from coastal settings subject to hypoxia can yield records of environmental changes over time scales ranging from decades to millennia, sometimes with a resolution of as little as a few years. A variety of biological and geochemical indicators (proxies) derived from such cores have been used to reconstruct the development of eutrophication and hypoxic conditions over time. Those based on (1) the preserved remains of benthic organisms (mainly foraminiferans and ostracods), (2) sedimentary features (e.g. laminations) and (3) sediment chemistry and mineralogy (e.g. presence of sulphides and redox-sensitive trace elements) reflect conditions at or close to the seafloor. Those based on (4) the preserved remains of planktonic organisms (mainly diatoms and dinoflagellates), (5) pigments and lipid biomarkers derived from prokaryotes and eukaryotes and (6) organic C, N and their stable isotope ratios reflect conditions in the water column. However, the interpretation of these indicators is not straightforward. A central difficulty concerns the fact that hypoxia is strongly correlated with, and often induced by, organic enrichment caused by eutrophication, making it difficult to separate the effects of these phenomena in sediment records. The problem is compounded by the enhanced preservation in anoxic and hypoxic sediments of organic microfossils and biomarkers indicating eutrophication. The use of hypoxiaCorrespondence to: A. J. Gooday (ang@noc.soton.ac.uk) specific proxies, such as the trace metals molybdenum and rhenium and the bacterial biomarker isorenieratene, together with multi-proxy approaches, may provide a way forward. All proxies of bottom-water hypoxia are basically qualitative; their quantification presents a major challenge to which there is currently no satisfactory solution. Finally, it is important to separate the effects of natural ecosystem variability from anthropogenic effects. Despite these problems, in the absence of historical data for dissolved oxygen concentrations, the analysis of sediment cores can provide plausible reconstructions of the temporal development of humaninduced hypoxia, and associated eutrophication, in vulnerable coastal environments.

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“…In one case, bulk microbial biomass was used to determine ␦ 13 C values (16), but there was not a concomitant determination of ␦ 13 C CO2 values, so that the carbon metabolism in situ could not be evaluated. Molecular markers of green sulfur bacteria are frequently used in geochemistry for reconstruction of past environmental conditions (19,21,24,42,43,53,55,57). However, the carbon metabolism of an extant natural community of green sulfur bacteria has never been investigated based on stable carbon isotope fractionation of specific biomarkers.…”

mentioning

confidence: 99%

Characterization and In Situ Carbon Metabolism of Phototrophic Consortia

Glaeser

Overmann

2003

Appl Environ Microbiol

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A dense population of the phototrophic consortium "Pelochromatium roseum" was investigated in the chemocline of a temperate holomictic lake (Lake Dagow, Brandenburg, Germany). Fluorescence in situ hybridization revealed that the brown epibionts of "P. roseum" constituted up to 37% of the total bacterial cell number and up to 88% of all green sulfur bacteria present in the chemocline. Specific amplification of 16S rRNA gene fragments of green sulfur bacteria and denaturing gradient gel electrophoresis fingerprinting yielded a maximum of four different DNA bands depending on the year of study, indicating that the diversity of green sulfur bacteria was low. The 465-bp 16S rRNA gene sequence of the epibiont of "P. roseum" was obtained after sorting of individual consortia by micromanipulation, followed by a highly sensitive PCR. The sequence obtained represents a new phylotype within the radiation of green sulfur bacteria. Maximum light-dependent H 14 CO 3 ؊ fixation in the chemocline in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea suggested that there was anaerobic autotrophic growth of the green sulfur bacteria. The metabolism of the epibionts was further studied by determining stable carbon isotope ratios (␦ 13 C) of their specific biomarkers. Analysis of photosynthetic pigments by high-performance liquid chromatography revealed the presence of high concentrations of bacteriochlorophyll (BChl) e and smaller amounts of BChl a and d and chlorophyll a in the chemocline. Unexpectedly, isorenieratene and ␤-isorenieratene, carotenoids typical of other brown members of the green sulfur bacteria, were absent. Instead, four different esterifying alcohols of BChl e were isolated as biomarkers of green sulfur bacterial epibionts, and their ␦ 13 C values were determined. Farnesol, tetradecanol, hexadecanol, and hexadecenol all were significantly enriched in 13 C compared to bulk dissolved and particulate organic carbon and compared to the biomarkers of purple sulfur bacteria. The difference between the ␦ 13 C values of farnesol, the major esterifying alcohol of BChl e, and CO 2 was ؊7.1%, which provides clear evidence that the mode of growth of the green sulfur bacterial epibionts of "P. roseum" in situ is photoautotrophic.Phototrophic consortia are unique, highly structured aggregates consisting of colorless bacteria and green sulfur bacteria (34,37,41,44,52). In motile phototrophic consortia, numerous green sulfur bacteria (so-called epibionts) are attached around a single, flagellated, colorless cell of a member of the ␤ subclass of the Proteobacteria, thereby forming a barrel-shaped highly regular structure (14,15,37). Motile phototrophic consortia were first described in the early 20th century (7, 27) and since then have been detected in numerous stratified freshwater lakes and ponds worldwide (40). To date, seven different types of motile phototrophic consortia have been distinguished on the basis of color, size, and shape and on the basis of the number and morphology of the epibionts (41).Phototrophic conso...

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Sulphidic Mediterranean surface waters during Pliocene sapropel formation

Cited by 169 publications

References 27 publications

Controls on phosphorus regeneration and burial during formation of eastern Mediterranean sapropels

Controls on phosphorus regeneration and burial during formation of eastern Mediterranean sapropels

Historical records of coastal eutrophication-induced hypoxia

Characterization and In Situ Carbon Metabolism of Phototrophic Consortia

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