Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania)

Abstract. Organic matter preserved in Lake Ohrid sediments originates from aquatic and terrestrial sources. Its variable composition reflects climate-controlled changes in the lake basin's hydrology and related organic matter export, i.e. changes in primary productivity, terrestrial plant matter input and soil erosion. Here, we present first results from lipid biomarker investigations of Lake Ohrid sediments from two near-shore settings: site Lz1120 near the southern shore, with low-lying lands nearby and probably influenced by river discharge, and site Co1202 which is close to the steep eastern slopes. Variable proportions of terrestrial n-alkanoic acids and n-alkanols as well as compositional changes of ω-hydroxy acids document differences in soil organic matter supply between the sites and during different climate stages (glacial, Holocene, 8.2 ka cooling event). Changes in the vegetation cover are suggested by changes in the dominant chain length of terrestrial n-alkanols. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. We found evidence for anoxic conditions within the photic zone by detecting epicholestanol and tetrahymanol from sulphur-oxidising phototrophic bacteria and bacterivorous ciliates and for the influence of a settled human community from the occurrence of coprostanol, a biomarker for human and animal faeces (pigs, sheep, goats), in an early Holocene sample. This study illustrates the potential of lipid biomarkers for future environmental reconstructions using one of Europe's oldest continental climate archives, Lake Ohrid.

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Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania)

Biogeosciences Discussions ◽

10.5194/bgd-7-4607-2010 ◽

2010 ◽

Vol 7 (3) ◽

pp. 4607-4640 ◽

Cited By ~ 7

Author(s):

J. Holtvoeth ◽

H. Vogel ◽

B. Wagner ◽

G. A. Wolff

Keyword(s):

Organic Matter ◽

Lipid Biomarkers ◽

Lake Ohrid ◽

Labile Organic Matter ◽

Glacial Sediments ◽

Plant Matter ◽

Lipid Biomarker ◽

First Results ◽

Near Shore ◽

Cattle Faeces

Abstract. Organic matter preserved in Lake Ohrid sediments originates from aquatic and terrestrial sources. Its variable composition reflects climate-controlled changes in the lake basin's hydrology and related organic matter export, i.e. changes in primary productivity, terrestrial plant matter input and soil erosion. Here, we present first results from lipid biomarker investigations of Lake Ohrid sediments from two near-shore settings: Site Lz1120 near the southern shore, with flat lands nearby and probably influenced by river discharge, and site Co1202 which is close to the steep eastern slopes. Variable proportions of terrestrial n-alkanoic acids and n-alkanols as well as compositional changes of ω-hydroxy acids document differences in soil organic matter supply between the sites and during different climate stages (glacial, Holocene, 8.2 ka cooling event). Changes in the vegetation cover are suggested by changes in the dominant chain length of terrestrial n-alkanols. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. We found evidence for anoxic conditions within the photic zone by detecting epicholestanol from sulphur-oxidising phototrophic bacteria and for the influence of an early human community from the occurrence of coprostanol, a biomarker for human and cattle faeces, in an early Holocene sample. This study illustrates the potential of lipid biomarkers for future environmental reconstructions using one of Europe's oldest continental climate archives, Lake Ohrid.

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Chemical investigation of lake sediments and their interpretation

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1965.0002 ◽

1965 ◽

Vol 161 (984) ◽

pp. 295-309 ◽

Cited By ~ 58

Keyword(s):

Organic Matter ◽

Lake Sediments ◽

Land Surface ◽

Drainage Basin ◽

Drainage System ◽

Labile Organic Matter ◽

Glacial Sediments ◽

Algal Material ◽

Lake Waters

Before any interpretation of compositional changes in a lake sediment column can be attempted, it is necessary to recognize the sources from which the sediment has been derived. Unlike bogs, whose deposits consist largely of materials synthesized in situ , lakes and particularly those of the Lake District, are greatly influenced by inflow and their sediments may derive material from a drainage basin some twenty or thirty times as large as the area of the lake itself. The glacial lake sediments consist wholly of mineral clay, often laminated, which must have been derived from the drainage basin. The post-Glacial sediments contain some 70 or 80 % of mineral material similarly derived. The remaining 20 to 30% consists of organic matter which may have originated photosynthetically either on the land surface or in the waters of the lake. The organic matter which eventually becomes buried in the sediment must have reached a state of stability towards oxidation since it must have been exposed to oxidizing conditions either in the soil or at the mud surface for many years before its final incorporation in the sediment. There is evidence from observations on Windermere and on Blelham Tarn, that the algal material produced in the lakes is very readily oxidized at the mud surface and that the oxygen consumed from the lake waters is largely used in oxidation of this comparatively labile organic matter. The major part of the organic material remaining in lake sediments is therefore likely to have been derived from stable residues produced in the soils of the drainage system . The sediment may then be regarded as an accumulation of debris derived from the land surface with minor additions from the lake biomass, though these latter additions may make important contributions to the precipitation of some elements of which phosphorus is an example. The information to be obtained from a study of lake sediments is therefore mainly concerned with events affecting the surrounding land surface rather than the lake itself, though conditions existing in the lake in former times may often be inferred from the sedimentary composition.

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Multiple lipid biomarkers record organic matter sources and paleoenvironmental changes in the East China Sea coast over the past 160 years

The Holocene ◽

10.1177/0959683620961500 ◽

2020 ◽

Vol 31 (1) ◽

pp. 16-27

Author(s):

Lilei Chen ◽

Feng Li ◽

Jian Liu ◽

Xingliang He

Keyword(s):

Fatty Acids ◽

Organic Matter ◽

20Th Century ◽

East China Sea ◽

Lipid Biomarkers ◽

East China ◽

Early 20Th Century ◽

The East China Sea ◽

China Sea ◽

Lipid Biomarker

The use of lipid biomarkers as paleoenvironmental proxies relies on an accurate assessment of their organic matter (OM) sources. In this study, we analyzed multiple lipids in core sediments recovered from the Zhejiang–Fujian coastal mud area to provide a 160-year record of OM input to the East China Sea (ECS) coastal sediments and to reconstruct paleoenvironmental conditions over this interval. The molecular composition of the samples was characterized by a mixture of natural lipids, particularly those derived from terrestrial vascular plants, marine/riverine plankton and macrophytes, and bacteria. The sources of some lipid components were ambiguous/mixed as they were potentially derived from multiple precursor organisms and because of limitations associated with modern survey techniques. There is evidence that early diagenesis caused the preferential degradation of labile aquatic lipids and that the degradation of terrestrial lipids was more severe when subjected to complex horizontal–vertical transportation processes associated with deposition, resuspension, and redeposition. These processes may have led to an enhanced terrestrial OM signal in the normal ( n)-alkane and n-alkanol records, which is at odds with, for example, those of the n-fatty acids, hopanoids, steranes, and sterols, which suggest a dominant marine OM source. Furthermore, we conclude that the occurrence of multiple sources, selective diagenesis, and test error has led to the distortion of redox and maturity indicators based on evidence from pristane-to-phytane (Pr/Ph) ratios and sterane/hopane indices in century scale. Overall, the phytol record suggests an increase in productivity after the early 20th century. Correspondingly, the diatom lipid biomarker records (based on C25 highly branched isoprenoid alkenes and C18:1ω9 fatty acids) reveal a fluctuating but overall increasing diatom productivity after the early 20th century, which coincides with a decreased proportion of the contribution from diatoms relative to that of total phytoplankton. This is believed to correspond to natural environmental changes, as well as anthropogenic impact.

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Improved end-member characterization of modern organic matter pools in the Ohrid Basin (Albania, Macedonia) and evaluation of new palaeoenvironmental proxies

Biogeosciences Discussions ◽

10.5194/bgd-12-12975-2015 ◽

2015 ◽

Vol 12 (15) ◽

pp. 12975-13039 ◽

Cited By ~ 4

Author(s):

J. Holtvoeth ◽

D. Rushworth ◽

A. Imeri ◽

M. Cara ◽

H. Vogel ◽

...

Keyword(s):

Organic Matter ◽

Chain Length ◽

Dicarboxylic Acids ◽

Ground Truth ◽

Average Chain Length ◽

Lake Ohrid ◽

Geochemical Fingerprinting ◽

Lipid Signal ◽

Lipid Biomarker ◽

Alkanoic Acids

Abstract. We present elemental, lipid biomarker and compound-specific isotope (δ13C, δ2H) data for soils and leaf litter collected in the catchment of Lake Ohrid (Albania, Macedonia), as well as macrophytes, particulate organic matter and sediments from the lake itself. Lake Ohrid provides an outstanding archive of continental environmental change of at least 1.2 M years and the purpose of our study is to ground truth organic geochemical proxies that we developed in order to study past changes in the terrestrial biome. We show that soils dominate the lipid signal of the lake sediments rather than the vegetation or aquatic biomass, while compound-specific isotopes (δ13C, δ2H) determined for n-alkanoic acids confirm a dominant terrestrial source of organic matter to the lake. There is a strong imprint of suberin monomers on the composition of total lipid extracts and chain-length distributions of n-alkanoic acids, n-alcohols, ω-hydroxy acids and α,ω-dicarboxylic acids. Our end-member survey identifies that ratios of mid-chain length suberin-derived to long-chain length cuticular-derived alkyl compounds as well as their average chain length distributions can be used as new molecular proxies of organic matter sources to the lake. We tested these for the 8.2 ka event, a pronounced and widespread Holocene climate fluctuation. In SE Europe climate became drier and cooler in response to the event, as is clearly recognizable in the carbonate and organic carbon records of Lake Ohrid sediments. Our new proxies indicate biome modification in response to hydrological changes, identifying two phases of increased soil OM supply, first from topsoils and then from mineral soils. Our study demonstrates that geochemical fingerprinting of terrestrial OM should focus on the main lipid sources, rather than the living biomass. Both can exhibit climate-controlled variability, but are generally not identical.

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Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

Biogeosciences ◽

10.5194/bg-11-3187-2014 ◽

2014 ◽

Vol 11 (12) ◽

pp. 3187-3204 ◽

Cited By ~ 2

Author(s):

C. López-Rodríguez ◽

A. Stadnitskaia ◽

G. J. De Lange ◽

F. Martínez-Ruíz ◽

M. Comas ◽

...

Keyword(s):

Organic Matter ◽

Western Mediterranean ◽

Lipid Biomarkers ◽

Anaerobic Oxidation Of Methane ◽

Mud Volcanoes ◽

Alboran Sea ◽

Methane Seepage ◽

Lipid Biomarker ◽

Biomarker Analysis ◽

Alborán Sea

Abstract. Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocentre containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, anaerobic oxidation of methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n alkane distributions and n alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S+22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotrophic archaea (irregular isoprenoids and dialkyl glycerol diethers) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected glycerol dialkyl glycerol tetraethers, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggests that no recent active methane seepage has occurred at these sites. Moreover, the observed methane concentrations support the current activity of Perejil MV, and the very low methane seepage activity in Kalinin and Schneider's Heart MVs.

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Measuring rates of gross photosynthesis and net community production in cryoconite holes: a comparison of field methods

Annals of Glaciology ◽

10.3189/172756411795932056 ◽

2010 ◽

Vol 51 (56) ◽

pp. 153-162 ◽

Cited By ~ 34

Author(s):

J. Telling ◽

A.M. Anesio ◽

J. Hawkings ◽

M. Tranter ◽

J.L. Wadham ◽

...

Keyword(s):

Organic Matter ◽

Molar Ratio ◽

Net Community Production ◽

Field Methods ◽

Labile Organic Matter ◽

Gross Photosynthesis ◽

Ice Melt ◽

Order Of Magnitude ◽

Community Production

AbstractPhotosynthesis by microbes on the surfaces of glaciers and ice sheets has the potential to fix carbon, alter the albedo of ice surfaces via the production of organic matter and so enhance ice melt. It could also be important for supplying labile organic matter and nutrients to in situ and downstream ecosystems. This study compares in situ 24 hour incubation methods for measuring rates of gross photosynthesis, respiration and net community production (NCP) in cryoconite holes on three Svalbard valley glaciers. Rates of gross photosynthesis and respiration measured by the ΔCO2method were closely balanced, resulting in rates of NCP close to the detection limit (mean of –1.3 μg C g−1d–1) consistent with previous measurements in Arctic cryoconite holes. This suggests that organic matter within cryoconite holes may be derived largely from allochthonous sources. The molar ratio of ΔO2to ΔCO2in incubations gave mean respiratory and photosynthetic quotients of 0.80 ± 0.17 (1 × SD) and 1.24 ± 0.20 (1 × SD), respectively. The 14C method typically underestimated rates of gross photosynthesis (ΔCO2method) by more than one order of magnitude and measured a rate closer to NCP.

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Intact polar lipids in the hadal seabed of the Atacama Trench point to lateral sediment transport and in situ production as key sources of labile organic matter

10.5194/bg-2021-232 ◽

2021 ◽

Author(s):

Edgart Flores ◽

Sebastian I. Cantarero ◽

Paula Ruiz-Fernández ◽

Nadia Dildar ◽

Matthias Zabel ◽

...

Keyword(s):

High Pressure ◽

Organic Matter ◽

Low Temperature ◽

Unsaturated Fatty Acids ◽

Euphotic Zone ◽

Polar Lipids ◽

Physiological Adaptation ◽

Labile Organic Matter ◽

Intact Polar Lipids

Abstract. Elevated concentrations of organic matter are found in sediments of hadal trenches relative to those found in the abyssal seabed, but the origin of such biological material remains elusive. Here, we report the composition and distribution of cell membrane intact polar lipids (IPLs) in surface sediments around the deepest points of the Atacama Trench and adjacent bathyal depths to assess and constrain the sources of labile organic matter in the hadal seabed. Multiscale bootstrap resampling of IPLs’ structural diversity and abundance indicates distinct lipid signatures in the sediments of the Atacama Trench that are more closely related to those found in bathyal sediments than to those previously reported for the upper ocean water column in the region. While the overall number of unique IPL structures in hadal sediments is limited and they contribute a small fraction of the total IPL pool, they include a high contribution of phospholipids with mono- and di-unsaturated fatty acids that are not associated with photoautotrophic sources. The diversity of labile IPLs in hadal sediments of the Atacama Trench suggests the presence of in situ microbial production and biomass that resembles traits of physiological adaptation to high pressure and low temperature, and/or the transport of labile organic matter from shallower sediment. We argue that the export of the most labile lipid component of the organic matter pool from the euphotic zone and the overlying oxygen minimum zone into the hadal sediments is neglectable. Our results contribute to the understanding of the mechanisms that control the delivery of labile organic matter to this extreme deep-sea ecosystem, whereas they provide insights into some potential physiological adaptation of the in situ microbial community to high pressure and low temperature through lipid remodeling.

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Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

Biogeosciences Discussions ◽

10.5194/bgd-10-18853-2013 ◽

2013 ◽

Vol 10 (11) ◽

pp. 18853-18892

Author(s):

C. López-Rodríguez ◽

A. Stadnitskaia ◽

G. J. De Lange ◽

F. Martínez-Ruíz ◽

M. Comas ◽

...

Keyword(s):

Organic Matter ◽

Western Mediterranean ◽

Lipid Biomarkers ◽

Anaerobic Oxidation Of Methane ◽

Mud Volcanoes ◽

Alboran Sea ◽

Methane Seepage ◽

Lipid Biomarker ◽

Biomarker Analysis ◽

Alborán Sea

Abstract. Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the Western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocenter containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, Anaerobic Oxidation of Methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n-alkane-distributions and n-alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S &plus; 22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotropic archaea (irregular isoprenoids and DGDs) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected GDGTs, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggest no recent active methane seepage has occurred at these sites. Moreover, the observed methane concentrations support the current activity of Perejil MV, and the very low methane seepage activity in Kalinin and Schneider's Heart MVs.

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