Articles | Volume 9, issue 12
https://doi.org/10.5194/bg-9-5081-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-9-5081-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
11 Dec 2012
Research article |
| 11 Dec 2012
Environmental variations in a semi-enclosed embayment (Amvrakikos Gulf, Greece) – reconstructions based on benthic foraminifera abundance and lipid biomarker pattern
S. Naeher
ETH Zurich, Institute for Biogeochemistry and Pollution Dynamics, Universitaetstrasse 16, 8092 Zurich, Switzerland
Eawag – Swiss Federal Institute of Aquatic Science and Technology, Department of Surface Waters – Research and Management, Seestrasse 79, 6047 Kastanienbaum, Switzerland
M. Geraga
University of Patras, Department of Geology, Laboratory of Marine Geology and Physical Oceanography, 26504 Patras, Greece
G. Papatheodorou
University of Patras, Department of Geology, Laboratory of Marine Geology and Physical Oceanography, 26504 Patras, Greece
G. Ferentinos
University of Patras, Department of Geology, Laboratory of Marine Geology and Physical Oceanography, 26504 Patras, Greece
H. Kaberi
Hellenic Centre for Marine Research, Institute of Oceanography, 46.7 km Athens-Sounio Avenue, 19013 Anavyssos, Greece
C. J. Schubert
Eawag – Swiss Federal Institute of Aquatic Science and Technology, Department of Surface Waters – Research and Management, Seestrasse 79, 6047 Kastanienbaum, Switzerland
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Climate change is anticipated to influence the biological pump by altering phytoplankton nutrient distribution. In our research, we collected measurements of particulate matter concentrations during two oceanographic field studies. We observed systematic variations in organic matter concentrations and ratios across the Atlantic Ocean. From statistical modeling, we determined that these variations are associated with differences in the availability of essential nutrients for phytoplankton growth.
Sebastian I. Cantarero, Edgart Flores, Harry Allbrook, Paulina Aguayo, Cristian A. Vargas, John E. Tamanaha, J. Bentley C. Scholz, Lennart T. Bach, Carolin R. Löscher, Ulf Riebesell, Balaji Rajagopalan, Nadia Dildar, and Julio Sepúlveda
Biogeosciences, 21, 3927–3958, https://doi.org/10.5194/bg-21-3927-2024, https://doi.org/10.5194/bg-21-3927-2024, 2024
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Our study explores lipid remodeling in response to environmental stress, specifically how cell membrane chemistry changes. We focus on intact polar lipids in a phytoplankton community exposed to diverse stressors in a mesocosm experiment. The observed remodeling indicates acyl chain recycling for energy storage in intact polar lipids during stress, reallocating resources based on varying growth conditions. This understanding is essential to grasp the system's impact on cellular pools.
Mengke Wang, Peng Zhang, Huishan Li, Guisen Deng, Deliang Kong, Sifang Kong, and Junjian Wang
Biogeosciences, 21, 2691–2704, https://doi.org/10.5194/bg-21-2691-2024, https://doi.org/10.5194/bg-21-2691-2024, 2024
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We developed and applied complementary analyses to characterize molecular-level carbon traits for water-grown and soil-grown fine roots. The adaptive strategy of developing more labile carbon in water-grown roots accelerated root decomposition and counteracted the decelerated effects of anoxia on decomposition, highlighting an indirect effect of environmental change on belowground carbon cycling.
Zhe-Xuan Zhang, Edith Parlanti, Christelle Anquetil, Jérôme Morelle, Anniet M. Laverman, Alexandre Thibault, Elisa Bou, and Arnaud Huguet
Biogeosciences, 21, 2227–2252, https://doi.org/10.5194/bg-21-2227-2024, https://doi.org/10.5194/bg-21-2227-2024, 2024
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Bacterial tetraethers have important implications for palaeoclimate reconstruction. However, fundamental understanding of how these lipids are transformed from land to sea and which environmental factors influence their distributions is lacking. Here, we investigate the sources of brGDGTs and brGMGTs and the factors controlling their distributions in a large dataset (n=237). We propose a novel proxy (RIX) to trace riverine runoff, which is applicable in modern systems and in paleorecord.
Youcheng Bai, Marie-Alexandrine Sicre, Jian Ren, Vincent Klein, Haiyan Jin, and Jianfang Chen
Biogeosciences, 21, 689–709, https://doi.org/10.5194/bg-21-689-2024, https://doi.org/10.5194/bg-21-689-2024, 2024
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Algal biomarkers were used to assess sea ice and pelagic algal production across the western Arctic Ocean with changing sea-ice conditions. They show three distinct areas along with a marked latitudinal gradient of sea ice over pelagic algal production in surface sediments that are reflected by the H-Print index. Our data also show that efficient grazing consumption accounted for the dramatic decrease of diatom-derived biomarkers in sediments compared to that of particulate matter.
Hanxiao Wang, Zhifei Liu, Jiaying Li, Baozhi Lin, Yulong Zhao, Xiaodong Zhang, Junyuan Cao, Jingwen Zhang, Hongzhe Song, and Wenzhuo Wang
Biogeosciences, 20, 5109–5123, https://doi.org/10.5194/bg-20-5109-2023, https://doi.org/10.5194/bg-20-5109-2023, 2023
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The sinking of zooplankton fecal pellets is a key process in the marine biological carbon pump. This study presents carbon export of four shapes of fecal pellets from two time-series sediment traps in the South China Sea. The results show that the sinking fate of fecal pellets is regulated by marine primary productivity, deep-dwelling zooplankton community, and deep-sea currents in the tropical marginal sea, thus providing a new perspective for exploring the carbon cycle in the world ocean.
Rebecca J. Chmiel, Riss M. Kell, Deepa Rao, Dawn M. Moran, Giacomo R. DiTullio, and Mak A. Saito
Biogeosciences, 20, 3997–4027, https://doi.org/10.5194/bg-20-3997-2023, https://doi.org/10.5194/bg-20-3997-2023, 2023
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Cobalt is an important micronutrient for plankton, yet it is often scarce throughout the oceans. A 2017/2018 expedition to coastal Antarctica, including regions of the Amundsen Sea and the Ross Sea, discovered lower concentrations of cobalt compared to two past expeditions in 2005 and 2006, particularly for the type of cobalt preferred as a nutrient by phytoplankton. This loss may be due to changing inputs of other nutrients, causing higher uptake of cobalt by plankton over the last decade.
Emily B. Graham, Hyun-Seob Song, Samantha Grieger, Vanessa A. Garayburu-Caruso, James C. Stegen, Kevin D. Bladon, and Allison N. Myers-Pigg
Biogeosciences, 20, 3449–3457, https://doi.org/10.5194/bg-20-3449-2023, https://doi.org/10.5194/bg-20-3449-2023, 2023
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Intensifying wildfires are increasing pyrogenic organic matter (PyOM) production and its impact on water quality. Recent work indicates that PyOM may have a greater impact on aquatic biogeochemistry than previously assumed, driven by higher bioavailability. We provide a full assessment of the potential bioavailability of PyOM across its chemical spectrum. We indicate that PyOM can be actively transformed within the river corridor and, therefore, may be a growing source of riverine C emissions.
Nora Richter, Ellen C. Hopmans, Danica Mitrović, Pedro M. Raposeiro, Vítor Gonçalves, Ana C. Costa, Linda A. Amaral-Zettler, Laura Villanueva, and Darci Rush
Biogeosciences, 20, 2065–2098, https://doi.org/10.5194/bg-20-2065-2023, https://doi.org/10.5194/bg-20-2065-2023, 2023
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Bacteriohopanepolyols (BHPs) are a diverse class of lipids produced by bacteria across a wide range of environments. This study characterizes the diversity of BHPs in lakes and coastal lagoons in the Azores Archipelago, as well as a co-culture enriched for methanotrophs. We highlight the potential of BHPs as taxonomic markers for bacteria associated with certain ecological niches, which can be preserved in sedimentary records.
Andrea Scheibe, Carlos A. Sierra, and Marie Spohn
Biogeosciences, 20, 827–838, https://doi.org/10.5194/bg-20-827-2023, https://doi.org/10.5194/bg-20-827-2023, 2023
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We explored carbon cycling in soils in three climate zones in Chile down to a depth of 6 m, using carbon isotopes. Our results show that microbial activity several meters below the soil surface is mostly fueled by recently fixed carbon and that strong decomposition of soil organic matter only occurs in the upper decimeters of the soils. The study shows that different layers of the critical zone are tightly connected and that processes in the deep soil depend on recently fixed carbon.
Melissa Sophia Schwab, Hannah Gies, Chantal Valérie Freymond, Maarten Lupker, Negar Haghipour, and Timothy Ian Eglinton
Biogeosciences, 19, 5591–5616, https://doi.org/10.5194/bg-19-5591-2022, https://doi.org/10.5194/bg-19-5591-2022, 2022
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The majority of river studies focus on headwater or floodplain systems, while often neglecting intermediate river segments. Our study on the subalpine Sihl River bridges the gap between streams and lowlands and demonstrates that moderately steep river segments are areas of significant instream alterations, modulating the export of organic carbon over short distances.
Lisa Noll, Shasha Zhang, Qing Zheng, Yuntao Hu, Florian Hofhansl, and Wolfgang Wanek
Biogeosciences, 19, 5419–5433, https://doi.org/10.5194/bg-19-5419-2022, https://doi.org/10.5194/bg-19-5419-2022, 2022
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Cleavage of proteins to smaller nitrogen compounds allows microorganisms and plants to exploit the largest nitrogen reservoir in soils and is considered the bottleneck in soil organic nitrogen cycling. Results from soils covering a European transect show that protein turnover is constrained by soil geochemistry, shifts in climate and associated alterations in soil weathering and should be considered as a driver of soil nitrogen availability with repercussions on carbon cycle processes.
Muhammed Fatih Sert, Helge Niemann, Eoghan P. Reeves, Mats A. Granskog, Kevin P. Hand, Timo Kekäläinen, Janne Jänis, Pamela E. Rossel, Bénédicte Ferré, Anna Silyakova, and Friederike Gründger
Biogeosciences, 19, 2101–2120, https://doi.org/10.5194/bg-19-2101-2022, https://doi.org/10.5194/bg-19-2101-2022, 2022
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We investigate organic matter composition in the Arctic Ocean water column. We collected seawater samples from sea ice to deep waters at six vertical profiles near an active hydrothermal vent and its plume. In comparison to seawater, we found that the organic matter in waters directly affected by the hydrothermal plume had different chemical composition. We suggest that hydrothermal processes may influence the organic matter distribution in the deep ocean.
Charlotte Haugk, Loeka L. Jongejans, Kai Mangelsdorf, Matthias Fuchs, Olga Ogneva, Juri Palmtag, Gesine Mollenhauer, Paul J. Mann, P. Paul Overduin, Guido Grosse, Tina Sanders, Robyn E. Tuerena, Lutz Schirrmeister, Sebastian Wetterich, Alexander Kizyakov, Cornelia Karger, and Jens Strauss
Biogeosciences, 19, 2079–2094, https://doi.org/10.5194/bg-19-2079-2022, https://doi.org/10.5194/bg-19-2079-2022, 2022
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Buried animal and plant remains (carbon) from the last ice age were freeze-locked in permafrost. At an extremely fast eroding permafrost cliff in the Lena Delta (Siberia), we found this formerly frozen carbon well preserved. Our results show that ongoing degradation releases substantial amounts of this carbon, making it available for future carbon emissions. This mobilisation at the studied cliff and also similarly eroding sites bear the potential to affect rivers and oceans negatively.
Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, and Patrick G. Hatcher
Biogeosciences, 19, 1491–1514, https://doi.org/10.5194/bg-19-1491-2022, https://doi.org/10.5194/bg-19-1491-2022, 2022
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Wildfire-derived molecules are ubiquitous in the aquatic environment, but their biological fate remains understudied. We have evaluated the compositional changes that occur to wildfire-derived molecules after incubation with soil microbes. We observe a significant degradation but also a production of numerous new labile molecules. Our results indicate that wildfire-derived molecules can be broken down and the carbon and nitrogen therein can be incorporated into microbial food webs.
Edgart Flores, Sebastian I. Cantarero, Paula Ruiz-Fernández, Nadia Dildar, Matthias Zabel, Osvaldo Ulloa, and Julio Sepúlveda
Biogeosciences, 19, 1395–1420, https://doi.org/10.5194/bg-19-1395-2022, https://doi.org/10.5194/bg-19-1395-2022, 2022
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In this study, we investigate the chemical diversity and abundance of microbial lipids as markers of organic matter sources in the deepest points of the Atacama Trench sediments and compare them to similar lipid stocks in shallower surface sediments and in the overlying water column. We evaluate possible organic matter provenance and some potential chemical adaptations of the in situ microbial community to the extreme conditions of high hydrostatic pressure in hadal realm.
Birgit Gaye, Niko Lahajnar, Natalie Harms, Sophie Anna Luise Paul, Tim Rixen, and Kay-Christian Emeis
Biogeosciences, 19, 807–830, https://doi.org/10.5194/bg-19-807-2022, https://doi.org/10.5194/bg-19-807-2022, 2022
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Amino acids were analyzed in a large number of samples of particulate and dissolved organic matter from coastal regions and the open ocean. A statistical analysis produced two new biogeochemical indicators. An indicator of sinking particle and sediment degradation (SDI) traces the degradation of organic matter from the surface waters into the sediments. A second indicator shows the residence time of suspended matter in the ocean (RTI).
Zoë R. van Kemenade, Laura Villanueva, Ellen C. Hopmans, Peter Kraal, Harry J. Witte, Jaap S. Sinninghe Damsté, and Darci Rush
Biogeosciences, 19, 201–221, https://doi.org/10.5194/bg-19-201-2022, https://doi.org/10.5194/bg-19-201-2022, 2022
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Anaerobic ammonium oxidation (anammox) is an important nitrogen-removal process in the ocean. We assess the distribution of bacteriohopanetetrol-x (BHT-x), used to trace past anammox, along a redox gradient in the water column of the Benguela upwelling system. BHT-x / BHT ratios of >0.18 correspond to the presence of living anammox bacteria and oxygen levels <50 μmol L−1. This allows for a more robust application of BHT-x to trace past marine anammox and deoxygenation in dynamic marine systems.
Jia-Jang Hung, Ching-Han Tung, Zong-Ying Lin, Yuh-ling Lee Chen, Shao-Hung Peng, Yen-Huei Lin, and Li-Shan Tsai
Biogeosciences, 18, 5141–5162, https://doi.org/10.5194/bg-18-5141-2021, https://doi.org/10.5194/bg-18-5141-2021, 2021
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We report measured active and passive fluxes and their controlling mechanisms in the northern South China Sea (NSCS). The total fluxes were higher than most reports in open oceans, indicating the significance of NSCS in atmospheric CO2 uptake and in storing that CO2 in the ocean’s interior. Winter cooling and extreme events enhanced nutrient availability and elevated fluxes. Global warming may have profound impacts on reducing ocean’s uptake and storage of CO2 in subtropical–tropical oceans.
Jens Daniel Müller, Bernd Schneider, Ulf Gräwe, Peer Fietzek, Marcus Bo Wallin, Anna Rutgersson, Norbert Wasmund, Siegfried Krüger, and Gregor Rehder
Biogeosciences, 18, 4889–4917, https://doi.org/10.5194/bg-18-4889-2021, https://doi.org/10.5194/bg-18-4889-2021, 2021
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Based on profiling pCO2 measurements from a field campaign, we quantify the biomass production of a cyanobacteria bloom in the Baltic Sea, the export of which would foster deep water deoxygenation. We further demonstrate how this biomass production can be accurately reconstructed from long-term surface measurements made on cargo vessels in combination with modelled temperature profiles. This approach enables a better understanding of a severe concern for the Baltic’s good environmental status.
Alexander Braun, Marina Spona-Friedl, Maria Avramov, Martin Elsner, Federico Baltar, Thomas Reinthaler, Gerhard J. Herndl, and Christian Griebler
Biogeosciences, 18, 3689–3700, https://doi.org/10.5194/bg-18-3689-2021, https://doi.org/10.5194/bg-18-3689-2021, 2021
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It is known that CO2 fixation by photoautotrophic organisms is the major sink from the atmosphere. While biologists are aware that CO2 fixation also occurs in heterotrophic organisms, this route of inorganic carbon, and its quantitative role, is hardly recognized in biogeochemistry. We demonstrate that a considerable amount of CO2 is fixed annually through anaplerotic reactions in heterotrophic organisms, and a significant quantity of inorganic carbon is temporally sequestered in biomass.
Jonathan H. Raberg, David J. Harning, Sarah E. Crump, Greg de Wet, Aria Blumm, Sebastian Kopf, Áslaug Geirsdóttir, Gifford H. Miller, and Julio Sepúlveda
Biogeosciences, 18, 3579–3603, https://doi.org/10.5194/bg-18-3579-2021, https://doi.org/10.5194/bg-18-3579-2021, 2021
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BrGDGT lipids are a proxy for temperature in lake sediments, but other parameters like pH can influence them, and seasonality can affect the temperatures they record. We find a warm-season bias at 43 new high-latitude sites. We also present a new method that deconvolves the effects of temperature, pH, and conductivity and generate global calibrations for these variables. Our study provides new paleoclimate tools, insight into brGDGTs at the biochemical level, and a new method for future study.
Charlotte L. Spencer-Jones, Erin L. McClymont, Nicole J. Bale, Ellen C. Hopmans, Stefan Schouten, Juliane Müller, E. Povl Abrahamsen, Claire Allen, Torsten Bickert, Claus-Dieter Hillenbrand, Elaine Mawbey, Victoria Peck, Aleksandra Svalova, and James A. Smith
Biogeosciences, 18, 3485–3504, https://doi.org/10.5194/bg-18-3485-2021, https://doi.org/10.5194/bg-18-3485-2021, 2021
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Long-term ocean temperature records are needed to fully understand the impact of West Antarctic Ice Sheet collapse. Glycerol dialkyl glycerol tetraethers (GDGTs) are powerful tools for reconstructing ocean temperature but can be difficult to apply to the Southern Ocean. Our results show active GDGT synthesis in relatively warm depths of the ocean. This research improves the application of GDGT palaeoceanographic proxies in the Southern Ocean.
Alec W. Armstrong, Leanne Powers, and Michael Gonsior
Biogeosciences, 18, 3367–3390, https://doi.org/10.5194/bg-18-3367-2021, https://doi.org/10.5194/bg-18-3367-2021, 2021
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Living things decay into organic matter, which can dissolve into water (like tea brewing). Tea receives its color by absorbing light. Similarly, this material absorbs light, which can then cause chemical reactions that change it. By measuring changes in these optical properties, we found that materials from some places are more sensitive to light than others. Comparing sensitivity to light helps us understand where these materials come from and what happens as they move through water.
Ben J. Fisher, Johan C. Faust, Oliver W. Moore, Caroline L. Peacock, and Christian März
Biogeosciences, 18, 3409–3419, https://doi.org/10.5194/bg-18-3409-2021, https://doi.org/10.5194/bg-18-3409-2021, 2021
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Organic carbon can be protected from microbial degradation in marine sediments through association with iron minerals on 1000-year timescales. Despite the importance of this carbon sink, our spatial and temporal understanding of iron-bound organic carbon interactions globally is poor. Here we show that caution must be applied when comparing quantification of iron-bound organic carbon extracted by different methods as the extraction strength and method specificity can be highly variable.
Mark A. Stevenson, Suzanne McGowan, Emma J. Pearson, George E. A. Swann, Melanie J. Leng, Vivienne J. Jones, Joseph J. Bailey, Xianyu Huang, and Erika Whiteford
Biogeosciences, 18, 2465–2485, https://doi.org/10.5194/bg-18-2465-2021, https://doi.org/10.5194/bg-18-2465-2021, 2021
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We link detailed stable isotope and biomarker analyses from the catchments of three Arctic upland lakes on Disko Island (West Greenland) to a recent dated sediment core to understand how carbon cycling has changed over the past ~500 years. We find that the carbon deposited in sediments in these upland lakes is predominately sourced from in-lake production due to the catchment's limited terrestrial vegetation and elevation and that recent increases in algal production link with climate change.
Nadine T. Smit, Laura Villanueva, Darci Rush, Fausto Grassa, Caitlyn R. Witkowski, Mira Holzheimer, Adriaan J. Minnaard, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 18, 1463–1479, https://doi.org/10.5194/bg-18-1463-2021, https://doi.org/10.5194/bg-18-1463-2021, 2021
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Soils from an everlasting fire (gas seep) in Sicily, Italy, reveal high relative abundances of novel uncultivated mycobacteria and unique 13C-depleted mycocerosic acids (multi-methyl branched fatty acids) close to the main gas seep. Our results imply that mycocerosic acids in combination with their depleted δ13C values offer a new biomarker tool to study the role of soil mycobacteria as hydrocarbon consumers in the modern and past global carbon cycle.
Marcus P. S. Badger
Biogeosciences, 18, 1149–1160, https://doi.org/10.5194/bg-18-1149-2021, https://doi.org/10.5194/bg-18-1149-2021, 2021
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Reconstructing ancient atmospheric CO2 is an important aim of palaeoclimate science in order to understand the Earth's climate system. One method, the alkenone proxy based on molecular fossils of coccolithophores, has been recently shown to be ineffective at low-to-moderate CO2 levels. In this paper I show that this is likely due to changes in the biogeochemistry of the coccolithophores when there is low carbon availability, but for much of the Cenozoic the alkenone proxy should have utility.
Loes G. J. van Bree, Francien Peterse, Allix J. Baxter, Wannes De Crop, Sigrid van Grinsven, Laura Villanueva, Dirk Verschuren, and Jaap S. Sinninghe Damsté
Biogeosciences, 17, 5443–5463, https://doi.org/10.5194/bg-17-5443-2020, https://doi.org/10.5194/bg-17-5443-2020, 2020
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Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are used as a paleothermometer based on their temperature dependence in global soils, but aquatic production complicates their use in lakes. BrGDGTs in the water column of Lake Chala, East Africa, respond to oxygen conditions and mixing. Changes in their signal can be linked to bacterial community composition rather than membrane adaptation to changing conditions. Their integrated signal in the sediment reflects mean air temperature.
Alexandra N. Loginova, Andrew W. Dale, Frédéric A. C. Le Moigne, Sören Thomsen, Stefan Sommer, David Clemens, Klaus Wallmann, and Anja Engel
Biogeosciences, 17, 4663–4679, https://doi.org/10.5194/bg-17-4663-2020, https://doi.org/10.5194/bg-17-4663-2020, 2020
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We measured dissolved organic carbon (DOC), nitrogen (DON) and matter (DOM) optical properties in pore waters and near-bottom waters of the eastern tropical South Pacific off Peru. The difference between diffusion-driven and net fluxes of DOC and DON and qualitative changes in DOM optical properties suggested active microbial utilisation of the released DOM at the sediment–water interface. Our results suggest that the sediment release of DOM contributes to microbial processes in the area.
Gerard J. M. Versteegh, Alexander J. P. Houben, and Karin A. F. Zonneveld
Biogeosciences, 17, 3545–3561, https://doi.org/10.5194/bg-17-3545-2020, https://doi.org/10.5194/bg-17-3545-2020, 2020
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Anoxic sediments mostly contain much more organic matter than oxic ones, and therefore organic matter in anoxic settings is often considered to be preserved better than in oxic settings. However, through the analysis of the same fossil dinoflagellate cyst species from both oxic and anoxic settings, we show that at a molecular level the preservation in the oxic sediments may be better since in the anoxic setting the cyst macromolecule has been altered by postdepositional modification.
Jingjing Guo, Miriam Glendell, Jeroen Meersmans, Frédérique Kirkels, Jack J. Middelburg, and Francien Peterse
Biogeosciences, 17, 3183–3201, https://doi.org/10.5194/bg-17-3183-2020, https://doi.org/10.5194/bg-17-3183-2020, 2020
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The fluxes of soil organic carbon (OC) transport from land to sea are poorly constrained, mostly due to the lack of a specific tracer for soil OC. Here we evaluate the use of specific molecules derived from soil bacteria as a tracer for soil OC in a small river catchment. We find that the initial soil signal is lost upon entering the aquatic environment. However, the local environmental history of the catchment is reflected by these molecules in the lake sediments that act as their sink.
Zhuo-Yi Zhu, Joanne Oakes, Bradley Eyre, Youyou Hao, Edwin Sien Aun Sia, Shan Jiang, Moritz Müller, and Jing Zhang
Biogeosciences, 17, 2473–2485, https://doi.org/10.5194/bg-17-2473-2020, https://doi.org/10.5194/bg-17-2473-2020, 2020
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Samples were collected in August 2016 in the Rajang River and its estuary, with tropical forest in the river basin and peatland in the estuary. Organic matter composition was influenced by transportation in the river basin, whereas peatland added clear biodegraded parts to the fluvial organic matter, which implies modification of the initial lability and/or starting points in the subsequent degradation and alternation processes after the organic matter enters the sea.
Wenjie Xiao, Yasong Wang, Yongsheng Liu, Xi Zhang, Linlin Shi, and Yunping Xu
Biogeosciences, 17, 2135–2148, https://doi.org/10.5194/bg-17-2135-2020, https://doi.org/10.5194/bg-17-2135-2020, 2020
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The hadal zone (6–11 km depth) is the least explored habitat on Earth. We studied microbial branched glycerol dialkyl glycerol tetraethers (brGDGTs) in the Challenger Deep, Mariana Trench. One unique feature is the strong predominance of 6-methyl brGDGT, which likely reflects an adaption of brGDGT-producing bacteria to alkaline seawater and low temperature. BrGDGTs, with elemental and isotopic data, suggest an autochthonous product for brGDGT. A new approach is proposed for brGDGT sourcing.
Yuge Bai, Edisson Subdiaga, Stefan B. Haderlein, Heike Knicker, and Andreas Kappler
Biogeosciences, 17, 683–698, https://doi.org/10.5194/bg-17-683-2020, https://doi.org/10.5194/bg-17-683-2020, 2020
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Biogeochemical processes of SOM are key for greenhouse gas emission and water quality. We extracted SOM by water or by NaOH–HCl under oxic–anoxic conditions. Chemical and anoxic extractions lead to higher SOM electron exchange capacities, resulting in stimulation of microbial Fe(III) reduction. Therefore, aqueous pH-neutral SOM extracts should be used to reflect environmental SOM redox processes, and artifacts of chemical extractions need to be considered when evaluating SOM redox processes.
Yan Shen, Volker Thiel, Pablo Suarez-Gonzalez, Sebastiaan W. Rampen, and Joachim Reitner
Biogeosciences, 17, 649–666, https://doi.org/10.5194/bg-17-649-2020, https://doi.org/10.5194/bg-17-649-2020, 2020
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Today, sterols are widespread in plants, animals, and fungi but are almost absent in the oldest rocks. Microbial mats, representing the earliest complex ecosystems on Earth, were omnipresent in Precambrian marine environments and may have degraded the sterols at that time. Here we analyze the distribution of sterols through a microbial mat. This provides insight into how variations in biological and nonbiological factors affect the preservation of sterols in modern and ancient microbial mats.
Sarah Coffinet, Travis B. Meador, Lukas Mühlena, Kevin W. Becker, Jan Schröder, Qing-Zeng Zhu, Julius S. Lipp, Verena B. Heuer, Matthew P. Crump, and Kai-Uwe Hinrichs
Biogeosciences, 17, 317–330, https://doi.org/10.5194/bg-17-317-2020, https://doi.org/10.5194/bg-17-317-2020, 2020
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This study deals with two membrane lipids called BDGTs and PDGTs. Membrane lipids are molecules forming the cell envelope of all organisms. Different organisms produce different lipids thus they can be used to detect the presence of specific organisms in the environment. We analyzed the structure of these new lipids and looked for potential producers. We found that they are likely made by microbes emitting methane below the sediment surface and could be used to track these specific microbes.
Ying Wu, Kun Zhu, Jing Zhang, Moritz Müller, Shan Jiang, Aazani Mujahid, Mohd Fakharuddin Muhamad, and Edwin Sien Aun Sia
Biogeosciences, 16, 4517–4533, https://doi.org/10.5194/bg-16-4517-2019, https://doi.org/10.5194/bg-16-4517-2019, 2019
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Our understanding of terrestrial organic matter (TOM) in tropical peat-draining rivers remains limited, especially in Southeast Asia. We explored the characteristics of TOM via bulk parameters and lignin phenols of sediment in Malaysia. This showed that the most important plant source of the organic matter in these rivers is woody angiosperm C3 plants with limited diagenetic alteration. This slower degradation of TOM may be a link to higher total nitrogen content, especially for the small river.
Caitlyn R. Witkowski, Sylvain Agostini, Ben P. Harvey, Marcel T. J. van der Meer, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 16, 4451–4461, https://doi.org/10.5194/bg-16-4451-2019, https://doi.org/10.5194/bg-16-4451-2019, 2019
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Carbon dioxide concentrations (pCO2) in the atmosphere play an integral role in Earth system dynamics, especially climate. Past climates help us understand future ones, but reconstructing pCO2 over the geologic record remains a challenge. This research demonstrates new approaches for exploring past pCO2 via the carbon isotope fractionation in general algal lipids, which we test over a high CO2 gradient from a naturally occurring CO2 seep.
Yongli Zhou, Patrick Martin, and Moritz Müller
Biogeosciences, 16, 2733–2749, https://doi.org/10.5194/bg-16-2733-2019, https://doi.org/10.5194/bg-16-2733-2019, 2019
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We found that peatlands in coastal Sarawak, Borneo, export extremely humified organic matter, which dominates the riverine organic matter pool and conservatively mixes with seawater, while the freshly produced fraction is low and stable in concentration at all salinities. We estimated that terrigenous fractions, which showed high photolability, still account for 20 % of the coastal dissolved organic carbon pool, implying the importance of peat-derived organic matter in the coastal carbon cycle.
Cited articles
Airoldi, L. and Beck, M. W.: Loss, status and trends for coastal marine habitats of Europe, Oceanogr. Mar. Biol., 45, 345–405, 2007.
Almogi-Labin, A., Perelis-Grossovicz, L., and Raab, M.: Living ammonia from a hypersaline inland pool, Dead Sea area, Israel, J. Foramin. Res., 22, 257–266, 1992.
Anastasakis, G., Piper, D. J. W., and Tziavos, C.: Sedimentological response to neotectonics and sea-level change in a delta-fed, complex graben: Gulf of Amvrakikos, western Greece, Mar. Geol., 236, 27–44, 2007.
Angel, D. L., Verghese, S., Lee, J. J., Saleh, A. M., Zuber, D., Lindell, D., and Symons, A.: Impact of a net cage fish farm on the distribution of benthic foraminifera in the Northern Gulf of Eilat (Aqaba, Red Sea), J. Foramin. Res., 30, 54–65, 2000.
Appleby, P. G. and Oldfield, F.: The calculation of lead-210 dates assuming a constant rate of supply of unsupported 210Pb to the sediment, Catena, 5, 1–8, 1978.
Barmawidjaja, D. M., van der Zwaan, G. J., Jorissen, F. J., and Puskaric, S.: 150 years of eutrophication in the northern Adriatic Sea - Evidence from a benthic foraminiferal record, Mar. Geol., 122, 367–384, 1995.
Bechtel, A. and Schubert, C. J.: A biogeochemical study of sediments from the eutrophic Lake Lugano and the oligotrophic Lake Brienz, Switzerland, Org. Geochem., 40, 1100–1114, 2009.
Blackwelder, P., Hood, T., Alvarez-Zarikian, C., Nelsen, T. A., and McKee, B.: Benthic foraminifera from the NECOP study area impacted by the Mississippi River plume and seasonal hypoxia, Quatern. Int., 31, 19–36, 1996.
Brocks, J. J. and Summons, R. E.: Sedimentary hydrocarbons, biomarkers for early life, in: Treatise in Geochemistry, edited by: Holland, H. D. and Turekian, K., Biogeochemistry, 8, 65–115, Elsevier, Oxford, 2003.
Buzas, M. A. and Gibson, T. G.: Species diversity: Benthonic foraminifera in western North Atlantic, Science, 163, 72–75, 1969.
Cole, M. L., Valiela, I., Kroeger, K. D., Tomasky, G. L., Cebrian, J., Wigand, C., McKinney, R. A., Grady, S. P., and Carvalho da Silva, M. H.: Assessment of a δ15N isotopic method to indicate anthropogenic eutrophication in aquatic ecosystems, J. Environ. Qual., 33, 124–132, 2004.
Debenay, J. P. and Guillou, J. J.: Ecological transitions indicated by foraminiferal assemblages in paralic environments, Estuaries, 25, 1107–1120, 2002.
Debenay, J. P., Millet, B., and Angelidis, M. O.: Relationships between foraminiferal assemblages and hydrodynamics in the Gulf of Kalloni, Greece, J. Foramin. Res., 35, 327–343, 2005.
Diaz, R. J. and Rosenberg, R.: Spreading dead zones and consequences for marine ecosystems, Science, 321, 926–929, 2008.
Ferentinos, G., Papatheodorou, G., Geraga, M., Iatrou, M., Fakiris, E., Christodoulou, D., Dimitriou, E., and Koutsikopoulos, C.: Fjord water circulation patterns and dysoxic/anoxic conditions in a Mediterranean semi-enclosed embayment in the Amvrakikos Gulf, Greece, Estuar. Coast. Shelf S., 88, 473–481, 2010.
Ficken, K. J., Li, B., Swain, D. L., and Eglinton, G.: An n-alkane proxy for the sedimentary input of submerged/floating freshwater aquatic macrophytes, Org. Geochem., 31, 745–749, 2000.
Filipsson, H. L. and Nordberg, K.: A 200-year environmental record of a low-oxygen fjord, Sweden, elucidated by benthic foraminifera, sediment characteristics and hydrographic data, J. Foramin. Res., 34, 277–293, 2004.
Goineau, A., Fontanier, C., Jorissen, F. J., Lansard, B., Buscail, R., Mouret, A., Kerhervé, P., Zaragosi, S., Ernoult, E., Artéro, C., Anschutz, P., Metzger, E., and Rabouille, C.: Live (stained) benthic foraminifera from the Rhone prodelta (Gulf of Lion, NW Mediterranean): Environmental controls on a river-dominated shelf, J. Sea Res., 65, 58–75, 2011.
Green, E. P. and Short, F. T.: World Atlas of Seagrasses, University of California Press, Berkeley, 2003.
Herbert, T. D.: Alkenone Paleotemperature Determinations, in: Treatise on Geochemistry, edited by: Heinrich, D. H. and Karl, K. T., Pergamon, Oxford, 391–432, 2003.
Hinrichs, K. U., Hmelo, L. R., and Sylva, S. P.: Molecular fossil record of elevated methane levels in late pleistocene coastal waters, Science, 299, 1214–1217, 2003.
Hyams-Kaphzan, O., Almogi-Labin, A., Benjamini, C., and Herut, B.: Natural oligotrophy vs. pollution-induced eutrophy on the SE Mediterranean shallow shelf (Israel): Environmental parameters and benthic foraminifera, Mar. Pollut. Bull., 58, 1888–1902, 2009.
Jasper, J. P. and Gagosian, R. B.: The sources and deposition of organic matter in the Late Quaternary Pigmy Basin, Gulf of Mexico, Geochim. Cosmochim. Ac., 54, 1117–1132, 1990.
Jorissen, F. J.: The distribution of benthic foraminifera in the Adriatic Sea, Mar. Micropaleontol., 12, 21–48, 1987.
Kapsimalis, V., Pavlakis, P., Poulos, S. E., Alexandri, S., Tziavos, C., Sioulas, A., Filippas, D., and Lykousis, V.: Internal structure and evolution of the Late Quaternary sequence in a shallow embayment: The Amvrakikos Gulf, NW Greece, Mar. Geol., 222, 399–418, 2005.
Kountoura, K. and Zacharias, I.: Temporal and spatial distribution of hypoxic/seasonal anoxic zone in Amvrakikos Gulf, Western Greece, Estuar. Coast. Shelf S., 94, 123–128, 2011.
Lancelot, C., Martin, J. M., Panin, N., and Zaitsev, Y.: The north-western Black Sea: A pilot site to understand the complex interaction between human activities and the coastal environment, Estuar. Coast. Shelf S., 54, 279–283, 2002.
Mateu-Vicens, G., Box, A., Deudero, S., and Rodriguez, B.: Comparative analysis of epiphytic foraminifera in sediments colonized by seagrass Posidonia oceanica and invasive macroalgae Caulerpa spp., J. Foramin. Res., 40, 134–147, 2010.
McCarroll, D. and Loader, N. J.: Stable isotopes in tree rings, Quaternary Sci. Rev., 23, 771–801, 2004.
Mee, L. D., Friedrich, J., and Gomoiu, M. T.: Restoring the Black Sea in times of uncertainty, Oceanography, 18, 32–43, 2005.
Mendes, I., Gonzalez, R., Dias, J. M. A., Lobo, F., and Martins, V.: Factors influencing recent benthic foraminifera distribution on the Guadiana shelf (Southwestern Iberia), Mar. Micropaleontol., 51, 171–192, 2004.
Meyers, P.: An Overview of Sediment Organic Matter Records of Human Eutrophication in the Laurentian Great Lakes Region, Water, Air & Soil Pollut. Focus, 6, 453–463, 2006.
Meyers, P. A. and Ishiwatari, R.: Lacustrine organic geochemistry - an overview of indicators of organic matter sources and diagenesis in lake sediments, Org. Geochem., 20, 867–900, 1993.
Mojtahid, M., Jorissen, F., Lansard, B., and Fontanier, C.: Microhabitat selection of benthic foraminifera in sediments off the Rhone River mouth (NW Mediterranean), J. Foramin. Res., 40, 231–246, 2010.
Müller, P. J., Kirst, G., Ruhland, G., von Storch, I., and Rosell-Melé, A.: Calibration of the alkenone paleotemperature index UK'37 based on core-tops from the eastern South Atlantic and the global ocean (60° N–60° S), Geochim. Cosmochim. Ac., 62, 1757–1772, 1998.
Murray, J. W.: Ecology and Palaeoecology of Benthic Foraminifera, Longman Scientific and Technical, New York, 2001.
Murray, J. W.: Ecology And Applications of Benthic Foraminifera, Cambridge University Press, Cambridge, 2006.
Murray, J. W., Stewart, K., Kassakian, S., Krynytzky, M., and DiJulio, D.: Oxic, Suboxic and Anoxic Conditions in the Black Sea, in: The Black Sea Food Question: Changes in Coastline, Climate and Human Settlement, edited by: Yanko-Hombach, V., Gilbert, A. S., Panin, N., and Dolukhanov, P. M., Springer, 1–22, 2007.
Naeher, S., Smittenberg, R. H., Gilli, A., Kirilova, E. P., Lotter, A. F., and Schubert, C. J.: Impact of recent lake eutrophication on microbial community changes as revealed by high resolution lipid biomarkers in Rotsee (Switzerland), Org. Geochem., 49, 86–95, 2012.
Ozsoy, E. and Unluata, U.: Oceanography of the Black Sea: a review of some recent results, Earth-Sci. Rev., 42, 231–272, 1997.
Papadimitriou, S., Kennedy, H., Kennedy, D. P., Duarte, C. M., and Marba, N.: Sources of organic matter in seagrass-colonized sediments: A stable isotope study of the silt and clay fraction from Posidonia oceanica meadows in the western Mediterranean, Org. Geochem., 36, 949–961, 2005.
Platon, E., Sen Gupta, B. K., Rabalais, N. N., and Turner, R. E.: Effect of seasonal hypoxia on the benthic foraminiferal community of the Louisiana inner continental shelf. The 20th century record, Mar. Micropaleontol., 54, 263–283, 2005.
Prahl, F. G. and Wakeham, S. G.: Calibration of unsaturation patterns in long-chain ketone compositions for palaeotemperature assessment, Nature, 330, 367–369, 1987.
Prahl, F. G., Muehlhausen, L. A., and Zahnle, D. L.: Further evaluation of long-chain alkenones as indicators of paleoceanographic conditions, Geochim. Cosmochim. Ac., 52, 2303–2310, 1988.
Rohmer, M., Bouviernave, P., and Ourisson, G.: Distribution of hopanoid triterpenes in prokaryotes, J. Gen. Microbiol., 130, 1137–1150, 1984.
Rontani, J.-F. and Volkman, J. K.: Phytol degradation products as biogeochemical tracers in aquatic environments, Org. Geochem., 34, 1–35, 2003.
Sackett, W. M.: The depositional history and isotopic organic carbon composition of marine sediments, Mar. Geol., 2, 173–185, 1964.
Schubert, C. J., Niggemann, J., Klockgether, G., and Ferdelman, T. G.: Chlorin Index: A new parameter for organic matter freshness in sediments, Geochem. Geophy. Geosy., 6, Q03005, https://doi.org/10.1029/2004GC000837, 2005.
Scott, D. B., Piper, D. J. W., and Panagos, A. G.: Recent saltmarsh and intertidal mudflat foraminifera from the western coast of Greece, Rivista Italiana de Paleontologia e Stratigrafia, 85, 243–266, 1979.
Sen Gupta, B. K. and Machain-Castillo, M. L.: Benthic foraminifera in oxygen-poor habitats, Mar. Micropaleontol., 20, 183–201, 1993.
Shannon, C. E.: A mathematical theory of communication, Bell Syst. Tech. J., 27, 379–423, 1948.
Sinninghe Damsté, J. S., Irene, W., Rijpstra, C., de Leeuw, J. W., and Schenck, P. A.: Origin of organic sulphur compounds and sulphur-containing high molecular weight substances in sediments and immature crude oils, Org. Geochem., 13, 593–606, 1988.
Sinninghe Damsté, J. S., Kenig, F., Koopmans, M. P., Koster, J., Schouten, S., Hayes, J. M., and De Leeuw, J. W.: Evidence for gammacerane as an indicator of water column stratification, Geochim. Cosmochim. Ac., 59, 1895–1900, 1995.
Sinninghe Damsté, J. S., Kuypers, M. M. M., Schouten, S., Schulte, S., and Rullkotter, R.: The lycopane/C$_{31}n$-alkane ratio as a proxy to assess palaeoxicity during sediment deposition, Earth. Planet. Sc. Lett., 209, 215–226, 2003.
Smittenberg, R. H., Pancost, R. D., Hopmans, E. C., Paetzel, M., and Sinninghe Damsté, J. S.: A 400-year record of environmental change in an euxinic fjord as revealed by the sedimentary biomarker record, Palaeogeogr. Palaeocl., 202, 331–351, 2004.
Spitzer, V.: Structure analysis of fatty acids by gas chromatography low resolution electron impact mass spectrometry of their 4,4-dimethyloxazoline derivatives – A review, Prog. Lipid Res., 35, 387–408, 1997.
Summons, R. E., Jahnke, L. L., and Simoneit, B. R. T.: Lipid Biomarkers for Bacterial Ecosystems: Studies of Cultured Organisms, Hydrothermal Environments and Ancient Sediments, in: Ciba Foundation Symposium 202 – Evolution of Hydrothermal Ecosystems on Earth and Mars, John Wiley and Sons, Chichester, 174–197, 2007.
Szarek, R., Kuhnt, W., Kawamura, H., and Kitazato, H.: Distribution of recent benthic foraminifera on the Sunda Shelf (South China Sea), Mar. Micropaleontol., 61, 171–195, 2006.
Thiel, V., Jenisch, A., Landmann, G., Reimer, A., and Michaelis, W.: Unusual distributions of long-chain alkenones and tetrahymanol from the highly alkaline Lake Van, Turkey, Geochim. Cosmochim. Ac., 61, 2053–2064, 1997.
Tsabaris, C., Evangeliou, N., Fillis-Tsirakis, E., Sotiropoulou, M., Patiris, D. L., and Florou, H.: Distribution of natural radioactivity in sediment cores from Amvrakikos gulf (Western Greece) as a part of IAEA's campaign in the Adriatic and Ionian Seas, Radiat. Prot. Dosimet., 1–14, 2011.
Tziavos, C. and Vouloumanos, N.: Microfaunal distribution in the surface sediments of Amvrakikos Gulf (Western Greece), Bulletin of the Geological Society of Greece, 30, 429–436, 1994.
van Breugel, Y., Schouten, S., Paetzel, M., and Sinninghe Damsté, J. S.: Seasonal variation in the stable carbon isotopic composition of algal lipids in a shallow anoxic fjord: Evaluation of the effect of recycling of respired CO2 on the δ13C of organic matter, Am. J. Sci., 306, 367–387, 2006.
van der Zwaan, G. J.: Variation in Natural vs. Anthropogenic Eutrophication of Shelf Areas in Front of Major Rivers, in: Environmental Micropaleontology, edited by: Martin, R. E., Kluwer, New York, 385–404, 2000.
Vidović, J., \'{C}osović, V., Juračić, M., and Petricioli, D.: Impact of fish farming on foraminiferal community, Drvenik Veliki Island, Adriatic Sea, Croatia, Mar. Pollut. Bull., 58, 1297–1309, 2009.
Volkman, J. K.: A review of sterol markers for marine and terrigenous organic matter, Org. Geochem., 9, 83–99, 1986.
Volkman, J. K.: Sterols in microorganisms, Appl. Microbiol. Biot., 60, 495–506, 2003.
Wakeham, S. G., Freeman, K. H., Pease, T. K., and Hayes, J. M.: A photoautotrophic source for lycopane in marine water columns, Geochim. Cosmochim. Ac., 57, 159–165, 1993.
Withers, N.: Dinoflagellate sterols, in: Marine Natural Products: Chemical and Biological Perspectives, edited by: Scheuer, P., Academic Press, New York, NY, 87–130, 1983.
Wu, J., Lin, L., Gagan, M., Schleser, G., and Wang, S.: Organic matter stable isotope (δ13C, δ15N) response to historical eutrophication of Lake Taihu, China, Hydrobiologia, 563, 19–29, 2006.
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