Articles | Volume 22, issue 7
https://doi.org/10.5194/bg-22-1887-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-22-1887-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Apr 2025
Research article |
| 17 Apr 2025
| 17 Apr 2025
Effects of photosymbiosis and related processes on planktic foraminifera-bound nitrogen isotopes in South Atlantic sediments
Alexandra Auderset
CORRESPONDING AUTHOR
School of Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, UK
Climate Geochemistry Department, Max Planck Institute for Chemistry Mainz, 55128 Mainz, Germany
Sandi M. Smart
Department of Geological Sciences, University of Alabama, Tuscaloosa, AL 35401, USA
Yeongjun Ryu
Department of Geosciences, Princeton University, Princeton, NJ 08544, USA
Dario Marconi
Department of Geosciences, Princeton University, Princeton, NJ 08544, USA
Haojia Abby Ren
Department of Geosciences, National Taiwan University, Taipei, 106, Taiwan
Lena Heins
Climate Geochemistry Department, Max Planck Institute for Chemistry Mainz, 55128 Mainz, Germany
Hubert Vonhof
Climate Geochemistry Department, Max Planck Institute for Chemistry Mainz, 55128 Mainz, Germany
Ralf Schiebel
Climate Geochemistry Department, Max Planck Institute for Chemistry Mainz, 55128 Mainz, Germany
Janne Repschläger
Climate Geochemistry Department, Max Planck Institute for Chemistry Mainz, 55128 Mainz, Germany
Daniel M. Sigman
Department of Geosciences, Princeton University, Princeton, NJ 08544, USA
Gerald H. Haug
Climate Geochemistry Department, Max Planck Institute for Chemistry Mainz, 55128 Mainz, Germany
Alfredo Martínez-García
Climate Geochemistry Department, Max Planck Institute for Chemistry Mainz, 55128 Mainz, Germany
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Many academic laboratories worldwide process environmental samples for analysis of membrane lipid molecules of archaea, for the reconstruction of past environmental conditions. However, the sample workup scheme involves many steps, each of which has a risk of contamination or bias, affecting the results. This paper reviews steps involved in sampling, extraction and analysis of lipids, interpretation and archiving of the data. This ensures reproducable, reusable, comparable and consistent data.
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Paleo-oxygen proxies can extend current records, constrain pre-anthropogenic baselines, provide datasets necessary to test climate models under different boundary conditions, and ultimately understand how ocean oxygenation responds on longer timescales. Here we summarize current proxies used for the reconstruction of Cenozoic seawater oxygen levels. This includes an overview of the proxy's history, how it works, resources required, limitations, and future recommendations.
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Bacterial lipids (branched glycerol dialkyl glycerol tetraethers; brGDGTs) extracted from lake sediments were used to reconstruct warm-season temperatures in central Europe during the past 60 kyr. Modern samples were used to test and correct for bias related to varying sources of brGDGTs. The temperature reconstruction is significantly correlated with other temperature reconstructions but features less millennial-scale variability, which is attributed to the seasonal signal of the proxy.
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Many academic laboratories worldwide process environmental samples for analysis of membrane lipid molecules of archaea, for the reconstruction of past environmental conditions. However, the sample workup scheme involves many steps, each of which has a risk of contamination or bias, affecting the results. This paper reviews steps involved in sampling, extraction and analysis of lipids, interpretation and archiving of the data. This ensures reproducable, reusable, comparable and consistent data.
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The pore density (number of pores per unit area) of unicellular eukaryotes is used to reconstruct past bottom-water nitrate at the Sea of Okhotsk, the Gulf of California, the Mexican Margin and the Gulf of Guayaquil. The reconstructed bottom-water nitrate at the Sea of Okhotsk, the Gulf of California and the Gulf of Guayaquil are influenced by the intermediate water masses, while the nitrate at the Mexican Margin is related to the deglacial NO3− variability in the Pacific Deep Water.
Babette A.A. Hoogakker, Catherine Davis, Yi Wang, Stephanie Kusch, Katrina Nilsson-Kerr, Dalton S. Hardisty, Allison Jacobel, Dharma Reyes Macaya, Nicolaas Glock, Sha Ni, Julio Sepúlveda, Abby Ren, Alexandra Auderset, Anya V. Hess, Katrin J. Meissner, Jorge Cardich, Robert Anderson, Christine Barras, Chandranath Basak, Harold J. Bradbury, Inda Brinkmann, Alexis Castillo, Madelyn Cook, Kassandra Costa, Constance Choquel, Paula Diz, Jonas Donnenfield, Felix J. Elling, Zeynep Erdem, Helena L. Filipsson, Sebastián Garrido, Julia Gottschalk, Anjaly Govindankutty Menon, Jeroen Groeneveld, Christian Hallmann, Ingrid Hendy, Rick Hennekam, Wanyi Lu, Jean Lynch-Stieglitz, Lélia Matos, Alfredo Martínez-García, Giulia Molina, Práxedes Muñoz, Simone Moretti, Jennifer Morford, Sophie Nuber, Svetlana Radionovskaya, Morgan Reed Raven, Christopher J. Somes, Anja S. Studer, Kazuyo Tachikawa, Raúl Tapia, Martin Tetard, Tyler Vollmer, Xingchen Wang, Shuzhuang Wu, Yan Zhang, Xin-Yuan Zheng, and Yuxin Zhou
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Hubert B. Vonhof, Sophie Verheyden, Dominique Bonjean, Stéphane Pirson, Michael Weber, Denis Scholz, John Hellstrom, Hai Cheng, Xue Jia, Kévin Di Modica, Gregory Abrams, Marjan A. P. van Nunen, Joost Ruiter, Michèlle van der Does, Daniel Böhl, and Jeroen H. J. L. van der Lubbe
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The sedimentary sequence in Scladina Cave (Belgium) is well-known for its rich archeological assemblages and its numerous faunal remains. Of particular interest is the presence of a nearly complete jaw bone of a Neanderthal child. In this study, we present new uranium series ages of stalagmites from the archeological sequence that allow more precise dating of the archeological finds. One key result is that the Neanderthal child may be slightly older than previously thought.
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Stefan Mulitza, Torsten Bickert, Helen C. Bostock, Cristiano M. Chiessi, Barbara Donner, Aline Govin, Naomi Harada, Enqing Huang, Heather Johnstone, Henning Kuhnert, Michael Langner, Frank Lamy, Lester Lembke-Jene, Lorraine Lisiecki, Jean Lynch-Stieglitz, Lars Max, Mahyar Mohtadi, Gesine Mollenhauer, Juan Muglia, Dirk Nürnberg, André Paul, Carsten Rühlemann, Janne Repschläger, Rajeev Saraswat, Andreas Schmittner, Elisabeth L. Sikes, Robert F. Spielhagen, and Ralf Tiedemann
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Stable isotope ratios of foraminiferal shells from deep-sea sediments preserve key information on the variability of ocean circulation and ice volume. We present the first global atlas of harmonized raw downcore oxygen and carbon isotope ratios of various planktonic and benthic foraminiferal species. The atlas is a foundation for the analyses of the history of Earth system components, for finding future coring sites, and for teaching marine stratigraphy and paleoceanography.
Sophie F. Warken, Therese Weißbach, Tobias Kluge, Hubert Vonhof, Denis Scholz, Rolf Vieten, Martina Schmidt, Amos Winter, and Norbert Frank
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The analysis of fluid inclusions from a Puerto Rican speleothem provides quantitative information about past rainfall conditions and temperatures during the Last Glacial Period, when the climate was extremely variable. Our data show that the region experienced a climate that was generally colder and drier. However, we also reconstruct intervals when temperatures reached nearly modern values, and convective activity was comparable to or only slightly weaker than the present day.
Annalena A. Lochte, Ralph Schneider, Markus Kienast, Janne Repschläger, Thomas Blanz, Dieter Garbe-Schönberg, and Nils Andersen
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The Labrador Sea is important for the modern global thermohaline circulation system through the formation of Labrador Sea Water. However, the role of the southward flowing Labrador Current in Labrador Sea convection is still debated. In order to better assess its role in deep-water formation and climate variability, we present high-resolution mid- to late Holocene records of sea surface and bottom water temperatures, freshening, and sea ice cover on the Labrador Shelf during the last 6000 years.
Patrick A. Rafter, Aaron Bagnell, Dario Marconi, and Timothy DeVries
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The N isotopic composition of nitrate (
nitrate δ15N) is a useful tracer of ocean N cycling and many other ocean processes. Here, we use a global compilation of marine nitrate δ15N as an input, training, and validating dataset for an artificial neural network (a.k.a.,
machine learning) and examine basin-scale trends in marine nitrate δ15N from the surface to the seafloor.
Janet E. Burke, Willem Renema, Michael J. Henehan, Leanne E. Elder, Catherine V. Davis, Amy E. Maas, Gavin L. Foster, Ralf Schiebel, and Pincelli M. Hull
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Metabolic rates are sensitive to environmental conditions and can skew geochemical measurements. However, there is no way to track these rates through time. Here we investigate the controls of test porosity in planktonic foraminifera (organisms commonly used in paleoclimate studies) as a potential proxy for metabolic rate. We found that the porosity varies with body size and temperature, two key controls on metabolic rate, and that it can respond to rapid changes in ambient temperature.
Miguel Mallo, Patrizia Ziveri, P. Graham Mortyn, Ralf Schiebel, and Michael Grelaud
Biogeosciences, 14, 2245–2266, https://doi.org/10.5194/bg-14-2245-2017, https://doi.org/10.5194/bg-14-2245-2017, 2017
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Single-celled living calcareous planktic foraminifera data across the Mediterranean Sea suggest that stratification of the surface water column, food availability, temperature, and seawater carbonate chemistry are the main factors controlling their distribution and mass. Increasing temperature, salinity, surface ocean stratification, and trophic conditions could be the causes of reduced abundance, diversity and species-specific changes in calcification in planktic foraminifera.
Janne Repschläger, Dieter Garbe-Schönberg, Mara Weinelt, and Ralph Schneider
Clim. Past, 13, 333–344, https://doi.org/10.5194/cp-13-333-2017, https://doi.org/10.5194/cp-13-333-2017, 2017
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Andreia Rebotim, Antje H. L. Voelker, Lukas Jonkers, Joanna J. Waniek, Helge Meggers, Ralf Schiebel, Igaratza Fraile, Michael Schulz, and Michal Kucera
Biogeosciences, 14, 827–859, https://doi.org/10.5194/bg-14-827-2017, https://doi.org/10.5194/bg-14-827-2017, 2017
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Planktonic foraminifera species depth habitat remains poorly constrained and the existing conceptual models are not sufficiently tested by observational data. Here we present a synthesis of living planktonic foraminifera abundance data in the subtropical eastern North Atlantic from vertical plankton tows. We also test potential environmental factors influencing the species depth habitat and investigate yearly or lunar migration cycles. These findings may impact paleoceanographic studies.
Angela N. Knapp, Sarah E. Fawcett, Alfredo Martínez-Garcia, Nathalie Leblond, Thierry Moutin, and Sophie Bonnet
Biogeosciences, 13, 4645–4657, https://doi.org/10.5194/bg-13-4645-2016, https://doi.org/10.5194/bg-13-4645-2016, 2016
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The goal of this manuscript was to track the fate of newly fixed nitrogen (N) in large volume mesocosms in the coastal waters of New Caledonia. We used a N isotope ("δ15N") budget and found a shift in the δ15N of sinking particulate N over the 23-day experiment, indicating that nitrate supported export production at the beginning of the experiment, but that nitrogen fixation supported export at the end. We infer that nitrogen fixation supported export production by a release of dissolved N.
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Biogeosciences, 22, 1095–1113, https://doi.org/10.5194/bg-22-1095-2025, https://doi.org/10.5194/bg-22-1095-2025, 2025
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Here we compare the Mg / Ca and oxygen isotope signatures for 57 recent to fossil species of planktonic foraminifera for the last 15 Myr. We find the occurrence of lineage-specific offsets in Mg / Ca conservative between ancestor-descendent species. Taking into account species kinship significantly improves temperature reconstructions, and we suggest that the occurrence of Mg / Ca offsets in modern species results from their evolution when ocean properties were different from today's.
Babette A.A. Hoogakker, Catherine Davis, Yi Wang, Stephanie Kusch, Katrina Nilsson-Kerr, Dalton S. Hardisty, Allison Jacobel, Dharma Reyes Macaya, Nicolaas Glock, Sha Ni, Julio Sepúlveda, Abby Ren, Alexandra Auderset, Anya V. Hess, Katrin J. Meissner, Jorge Cardich, Robert Anderson, Christine Barras, Chandranath Basak, Harold J. Bradbury, Inda Brinkmann, Alexis Castillo, Madelyn Cook, Kassandra Costa, Constance Choquel, Paula Diz, Jonas Donnenfield, Felix J. Elling, Zeynep Erdem, Helena L. Filipsson, Sebastián Garrido, Julia Gottschalk, Anjaly Govindankutty Menon, Jeroen Groeneveld, Christian Hallmann, Ingrid Hendy, Rick Hennekam, Wanyi Lu, Jean Lynch-Stieglitz, Lélia Matos, Alfredo Martínez-García, Giulia Molina, Práxedes Muñoz, Simone Moretti, Jennifer Morford, Sophie Nuber, Svetlana Radionovskaya, Morgan Reed Raven, Christopher J. Somes, Anja S. Studer, Kazuyo Tachikawa, Raúl Tapia, Martin Tetard, Tyler Vollmer, Xingchen Wang, Shuzhuang Wu, Yan Zhang, Xin-Yuan Zheng, and Yuxin Zhou
Biogeosciences, 22, 863–957, https://doi.org/10.5194/bg-22-863-2025, https://doi.org/10.5194/bg-22-863-2025, 2025
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Paleo-oxygen proxies can extend current records, constrain pre-anthropogenic baselines, provide datasets necessary to test climate models under different boundary conditions, and ultimately understand how ocean oxygenation responds on longer timescales. Here we summarize current proxies used for the reconstruction of Cenozoic seawater oxygen levels. This includes an overview of the proxy's history, how it works, resources required, limitations, and future recommendations.
Viorica Nagavciuc, Gerhard Helle, Maria Rădoane, Cătălin-Constantin Roibu, Mihai-Gabriel Cotos, and Monica Ionita
Biogeosciences, 22, 55–69, https://doi.org/10.5194/bg-22-55-2025, https://doi.org/10.5194/bg-22-55-2025, 2025
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We reconstructed drought conditions for the past 200 years for central and eastern parts of Europe (Romania) using δ18O in oak tree ring cellulose from Romania, revealing periods of both extreme wetness (e.g., 1905–1915) and dryness (e.g., 1818–1835). The most severe droughts occurred in the 19th and 21st centuries, likely linked to large-scale atmospheric circulation. This research highlights the potential of tree rings to improve our understanding of long-term climate variability in Europe.
Theresa M. King, Brad E. Rosenheim, and Noel P. James
Biogeosciences, 21, 5361–5379, https://doi.org/10.5194/bg-21-5361-2024, https://doi.org/10.5194/bg-21-5361-2024, 2024
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Corals can record ocean properties such as temperature in their skeletons. These records are useful for where and when we have no instrumental record like in the distant past. However, coral growth must be understood to interpret these records. Here, we analyze slices of a branching deep-sea coral from Antarctica to determine how to best sample these corals for past-climate work. We recommend sampling from the innermost portion of a coral skeleton for accurate temperature reconstructions.
Zita Kelemen, David P. Gillikin, and Steven Bouillon
EGUsphere, https://doi.org/10.5194/egusphere-2024-2714, https://doi.org/10.5194/egusphere-2024-2714, 2024
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We analysed the C and O stable isotope composition (δ13C, δ18O) across the growth axis of museum-archived and recent Chambardia wissmanni shells from the Oubangui River (Congo Basin) covering sections of the past ~120 years. Recent shells showed a much wider range in δ18O values compared to historical specimens, consistent with the suggestion that dry periods in the upper Congo basin are becoming more extreme in recent times; highlighting their potential to reconstruct hydroclimatic conditions.
Allix J. Baxter, Francien Peterse, Dirk Verschuren, Aihemaiti Maitituerdi, Nicolas Waldmann, and Jaap S. Sinninghe Damsté
Biogeosciences, 21, 2877–2908, https://doi.org/10.5194/bg-21-2877-2024, https://doi.org/10.5194/bg-21-2877-2024, 2024
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This study investigates the impact of long-term lake-system evolution on the climate signal recorded by glycerol dialkyl glycerol tetraethers (GDGTs), a popular biomarker in paleoclimate research. It compares downcore changes in GDGTs in the 250 000 year sediment sequence of Lake Chala (Kenya/Tanzania) to independent data for lake mixing and water-column chemistry. These factors influence the GDGT proxies in the earliest depositional phases (before ~180 ka), confounding the climate signal.
Frances A. Procter, Sandra Piazolo, Eleanor H. John, Richard Walshaw, Paul N. Pearson, Caroline H. Lear, and Tracy Aze
Biogeosciences, 21, 1213–1233, https://doi.org/10.5194/bg-21-1213-2024, https://doi.org/10.5194/bg-21-1213-2024, 2024
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This study uses novel techniques to look at the microstructure of planktonic foraminifera (single-celled marine organisms) fossils, to further our understanding of how they form their hard exterior shells and how the microstructure and chemistry of these shells can change as a result of processes that occur after deposition on the seafloor. Understanding these processes is of critical importance for using planktonic foraminifera for robust climate and environmental reconstructions of the past.
Josie L. Mottram, Anne M. Gothmann, Maria G. Prokopenko, Austin Cordova, Veronica Rollinson, Katie Dobkowski, and Julie Granger
Biogeosciences, 21, 1071–1091, https://doi.org/10.5194/bg-21-1071-2024, https://doi.org/10.5194/bg-21-1071-2024, 2024
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Knowledge of ancient ocean N cycling can help illuminate past climate change. Using field and lab studies, this work ground-truths a promising proxy for marine N cycling, the N isotope composition of cold-water coral (CWC) skeletons. Our results estimate N turnover in CWC tissue; quantify the isotope effects between CWC tissue, diet, and skeleton; and suggest that CWCs possibly feed mainly on metazoan zooplankton, suggesting that the marine N proxy may be sensitive to the food web structure.
Axelle Gardin, Emmanuelle Pucéat, Géraldine Garcia, Jean-Renaud Boisserie, Adélaïde Euriat, Michael M. Joachimski, Alexis Nutz, Mathieu Schuster, and Olga Otero
Biogeosciences, 21, 437–454, https://doi.org/10.5194/bg-21-437-2024, https://doi.org/10.5194/bg-21-437-2024, 2024
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We introduce a novel approach using stable oxygen isotopes from crocodilian fossil teeth to unravel palaeohydrological changes in past continental contexts. Applying it to the Plio-Pleistocene Ethiopian Shungura Formation, we found a significant increase in δ18O in the last 3 million years, likely due to monsoonal shifts and reduced rainfall, and that the local diversity of waterbodies (lakes, rivers, ponds) became restricted.
Angelica Feurdean, Richard S. Vachula, Diana Hanganu, Astrid Stobbe, and Maren Gumnior
Biogeosciences, 20, 5069–5085, https://doi.org/10.5194/bg-20-5069-2023, https://doi.org/10.5194/bg-20-5069-2023, 2023
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This paper presents novel results of laboratory-produced charcoal forms from various grass, forb and shrub taxa from the Eurasian steppe to facilitate more robust interpretations of fuel sources and fire types in grassland-dominated ecosystems. Advancements in identifying fuel sources and changes in fire types make charcoal analysis relevant to studies of plant evolution and fire management.
Joost Frieling, Linda van Roij, Iris Kleij, Gert-Jan Reichart, and Appy Sluijs
Biogeosciences, 20, 4651–4668, https://doi.org/10.5194/bg-20-4651-2023, https://doi.org/10.5194/bg-20-4651-2023, 2023
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We present a first species-specific evaluation of marine core-top dinoflagellate cyst carbon isotope fractionation (εp) to assess natural pCO2 dependency on εp and explore its geological deep-time paleo-pCO2 proxy potential. We find that εp differs between genera and species and that in Operculodinium centrocarpum, εp is controlled by pCO2 and nutrients. Our results highlight the added value of δ13C analyses of individual micrometer-scale sedimentary organic carbon particles.
Julia Homann, Niklas Karbach, Stacy A. Carolin, Daniel H. James, David Hodell, Sebastian F. M. Breitenbach, Ola Kwiecien, Mark Brenner, Carlos Peraza Lope, and Thorsten Hoffmann
Biogeosciences, 20, 3249–3260, https://doi.org/10.5194/bg-20-3249-2023, https://doi.org/10.5194/bg-20-3249-2023, 2023
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Cave stalagmites contain substances that can be used to reconstruct past changes in local and regional environmental conditions. We used two classes of biomarkers (polycyclic aromatic hydrocarbons and monosaccharide anhydrides) to detect the presence of fire and to also explore changes in fire regime (e.g. fire frequency, intensity, and fuel source). We tested our new method on a stalagmite from Mayapan, a large Maya city on the Yucatán Peninsula.
Claudia Voigt, Anne Alexandre, Ilja M. Reiter, Jean-Philippe Orts, Christine Vallet-Coulomb, Clément Piel, Jean-Charles Mazur, Julie C. Aleman, Corinne Sonzogni, Helene Miche, and Jérôme Ogée
Biogeosciences, 20, 2161–2187, https://doi.org/10.5194/bg-20-2161-2023, https://doi.org/10.5194/bg-20-2161-2023, 2023
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Data on past relative humidity (RH) ARE needed to improve its representation in Earth system models. A novel isotope parameter (17O-excess) of plant silica has been developed to quantify past RH. Using comprehensive monitoring and novel methods, we show how environmental and plant physiological parameters influence the 17O-excess of plant silica and leaf water, i.e. its source water. The insights gained from this study will help to improve estimates of RH from fossil plant silica deposits.
David J. Harning, Brooke Holman, Lineke Woelders, Anne E. Jennings, and Julio Sepúlveda
Biogeosciences, 20, 229–249, https://doi.org/10.5194/bg-20-229-2023, https://doi.org/10.5194/bg-20-229-2023, 2023
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In order to better reconstruct the geologic history of the North Water Polynya, we provide modern validations and calibrations of lipid biomarker proxies in Baffin Bay. We find that sterols, rather than HBIs, most accurately capture the current extent of the North Water Polynya and will be a valuable tool to reconstruct its past presence or absence. Our local temperature calibrations for GDGTs and OH-GDGTs reduce the uncertainty present in global temperature calibrations.
Jessica G. M. Crumpton-Banks, Thomas Tanner, Ivan Hernández Almeida, James W. B. Rae, and Heather Stoll
Biogeosciences, 19, 5633–5644, https://doi.org/10.5194/bg-19-5633-2022, https://doi.org/10.5194/bg-19-5633-2022, 2022
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Past ocean carbon is reconstructed using proxies, but it is unknown whether preparing ocean sediment for one proxy might damage the data given by another. We have tested whether the extraction of an organic proxy archive from sediment samples impacts the geochemistry of tiny shells also within the sediment. We find no difference in shell geochemistry between samples which come from treated and untreated sediment. This will help us to maximize scientific return from valuable sediment samples.
Pablo Forjanes, María Simonet Roda, Martina Greiner, Erika Griesshaber, Nelson A. Lagos, Sabino Veintemillas-Verdaguer, José Manuel Astilleros, Lurdes Fernández-Díaz, and Wolfgang W. Schmahl
Biogeosciences, 19, 3791–3823, https://doi.org/10.5194/bg-19-3791-2022, https://doi.org/10.5194/bg-19-3791-2022, 2022
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Aragonitic skeletons are employed to decipher past climate dynamics and environmental change. Unfortunately, the information that these skeletons keep can be destroyed during diagenesis. In this work, we study the first changes undergone by aragonitic skeletons upon hydrothermal alteration. We observe that major changes occur from the very beginning of the alteration, even without mineralogical changes. These results have major implications for the use of these archives to understand the past.
Inga Labuhn, Franziska Tell, Ulrich von Grafenstein, Dan Hammarlund, Henning Kuhnert, and Bénédicte Minster
Biogeosciences, 19, 2759–2777, https://doi.org/10.5194/bg-19-2759-2022, https://doi.org/10.5194/bg-19-2759-2022, 2022
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This study presents the isotopic composition of recent biogenic carbonates from several lacustrine species which calcify during different times of the year. The authors demonstrate that when biological offsets are corrected, the dominant cause of differences between species is the seasonal variation in temperature-dependent fractionation of oxygen isotopes. Consequently, such carbonates from lake sediments can provide proxy records of seasonal water temperature changes in the past.
Gerard J. M. Versteegh, Karin A. F. Zonneveld, Jens Hefter, Oscar E. Romero, Gerhard Fischer, and Gesine Mollenhauer
Biogeosciences, 19, 1587–1610, https://doi.org/10.5194/bg-19-1587-2022, https://doi.org/10.5194/bg-19-1587-2022, 2022
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A 5-year record of long-chain mid-chain diol export flux and composition is presented with a 1- to 3-week resolution sediment trap CBeu (in the NW African upwelling). All environmental parameters as well as the diol composition are dominated by the seasonal cycle, albeit with different phase relations for temperature and upwelling. Most diol-based proxies are dominated by upwelling. The long-chain diol index reflects temperatures of the oligotrophic summer sea surface.
Johannes Hepp, Christoph Mayr, Kazimierz Rozanski, Imke Kathrin Schäfer, Mario Tuthorn, Bruno Glaser, Dieter Juchelka, Willibald Stichler, Roland Zech, and Michael Zech
Biogeosciences, 18, 5363–5380, https://doi.org/10.5194/bg-18-5363-2021, https://doi.org/10.5194/bg-18-5363-2021, 2021
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Deriving more quantitative climate information like relative air humidity is one of the key challenges in paleostudies. Often only qualitative reconstructions can be done when single-biomarker-isotope data are derived from a climate archive. However, the coupling of hemicellulose-derived sugar with leaf-wax-derived n-alkane isotope results has the potential to overcome this limitation and allow a quantitative relative air humidity reconstruction.
Angelica Feurdean
Biogeosciences, 18, 3805–3821, https://doi.org/10.5194/bg-18-3805-2021, https://doi.org/10.5194/bg-18-3805-2021, 2021
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This study characterized the diversity of laboratory-produced charcoal morphological features of various fuel types from Siberia at different temperatures. The results obtained improve the attribution of charcoal particles to fuel types and fire characteristics. This work also provides recommendations for the application of this information to refine the past wildfire history.
Martin Tetard, Laetitia Licari, Ekaterina Ovsepyan, Kazuyo Tachikawa, and Luc Beaufort
Biogeosciences, 18, 2827–2841, https://doi.org/10.5194/bg-18-2827-2021, https://doi.org/10.5194/bg-18-2827-2021, 2021
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Oxygen minimum zones are oceanic regions almost devoid of dissolved oxygen and are currently expanding due to global warming. Investigation of their past behaviour will allow better understanding of these areas and better prediction of their future evolution. A new method to estimate past [O2] was developed based on morphometric measurements of benthic foraminifera. This method and two other approaches based on foraminifera assemblages and porosity were calibrated using 45 core tops worldwide.
Maximiliano Rodríguez and Christelle Not
Biogeosciences, 18, 1987–2001, https://doi.org/10.5194/bg-18-1987-2021, https://doi.org/10.5194/bg-18-1987-2021, 2021
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Mg/Ca in calcium carbonate shells of marine organisms such as foraminifera and ostracods has been used as a proxy to reconstruct water temperature. Here we provide new Mg/Ca–temperature calibrations for two shallow marine species of ostracods. We show that the water temperature in spring produces the best calibrations, which suggests the potential use of ostracod shells to reconstruct this parameter at a seasonal scale.
Hongrui Zhang, Chuanlian Liu, Luz María Mejía, and Heather Stoll
Biogeosciences, 18, 1909–1916, https://doi.org/10.5194/bg-18-1909-2021, https://doi.org/10.5194/bg-18-1909-2021, 2021
Delphine Dissard, Gert Jan Reichart, Christophe Menkes, Morgan Mangeas, Stephan Frickenhaus, and Jelle Bijma
Biogeosciences, 18, 423–439, https://doi.org/10.5194/bg-18-423-2021, https://doi.org/10.5194/bg-18-423-2021, 2021
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Results from a data set acquired from living foraminifera T. sacculifer collected from surface waters are presented, allowing us to establish a new Mg/Ca–Sr/Ca–temperature equation improving temperature reconstructions. When combining equations, δ18Ow can be reconstructed with a precision of ± 0.5 ‰, while successive reconstructions involving Mg/Ca and δ18Oc preclude salinity reconstruction with a precision better than ± 1.69. A new direct linear fit to reconstruct salinity could be established.
Feng Wang, Dominique Arseneault, Étienne Boucher, Shulong Yu, Steeven Ouellet, Gwenaëlle Chaillou, Ann Delwaide, and Lily Wang
Biogeosciences, 17, 4559–4570, https://doi.org/10.5194/bg-17-4559-2020, https://doi.org/10.5194/bg-17-4559-2020, 2020
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Wood stain is challenging the use of the blue intensity technique for dendroclimatic reconstructions. Using stained subfossil trees from eastern Canadian lakes, we compared chemical destaining approaches with the
delta bluemathematical correction of blue intensity data. Although no chemical treatment was completely efficient, the delta blue method is unaffected by the staining problem and thus is promising for climate reconstructions based on lake subfossil material.
Dulcinea V. Groff, David G. Williams, and Jacquelyn L. Gill
Biogeosciences, 17, 4545–4557, https://doi.org/10.5194/bg-17-4545-2020, https://doi.org/10.5194/bg-17-4545-2020, 2020
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Tussock grasses that grow along coastlines of the Falkland Islands are slow to decay and build up thick peat layers over thousands of years. Grass fragments found in ancient peat can be used to reconstruct past climate because grasses can preserve a record of growing conditions in their leaves. We found that modern living tussock grasses in the Falkland Islands reliably record temperature and humidity in their leaves, and the peat they form can be used to understand past climate change.
Maxence Guillermic, Sambuddha Misra, Robert Eagle, Alexandra Villa, Fengming Chang, and Aradhna Tripati
Biogeosciences, 17, 3487–3510, https://doi.org/10.5194/bg-17-3487-2020, https://doi.org/10.5194/bg-17-3487-2020, 2020
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Boron isotope ratios (δ11B) of foraminifera are a promising proxy for seawater pH and can be used to constrain pCO2. In this study, we derived calibrations for new foraminiferal taxa which extend the application of the boron isotope proxy. We discuss the origin of different δ11B signatures in species and also discuss the potential of using multispecies δ11B analyses to constrain vertical pH and pCO2 gradients in ancient water columns to shed light on biogeochemical carbon cycling in the past.
Zeynep Erdem, Joachim Schönfeld, Anthony E. Rathburn, Maria-Elena Pérez, Jorge Cardich, and Nicolaas Glock
Biogeosciences, 17, 3165–3182, https://doi.org/10.5194/bg-17-3165-2020, https://doi.org/10.5194/bg-17-3165-2020, 2020
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Recent observations from today’s oceans revealed that oxygen concentrations are decreasing, and oxygen minimum zones are expanding together with current climate change. With the aim of understanding past climatic events and their relationship with oxygen content, we looked at the fossils, called benthic foraminifera, preserved in the sediment archives from the Peruvian margin and quantified the bottom-water oxygen content for the last 22 000 years.
Hannah K. Donald, Gavin L. Foster, Nico Fröhberg, George E. A. Swann, Alex J. Poulton, C. Mark Moore, and Matthew P. Humphreys
Biogeosciences, 17, 2825–2837, https://doi.org/10.5194/bg-17-2825-2020, https://doi.org/10.5194/bg-17-2825-2020, 2020
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The boron isotope pH proxy is increasingly being used to reconstruct ocean pH in the past. Here we detail a novel analytical methodology for measuring the boron isotopic composition (δ11B) of diatom opal and apply this to the study of the diatom Thalassiosira weissflogii grown in culture over a range of pH. To our knowledge this is the first study of its kind and provides unique insights into the way in which diatoms incorporate boron and their potential as archives of palaeoclimate records.
Eleonora Fossile, Maria Pia Nardelli, Arbia Jouini, Bruno Lansard, Antonio Pusceddu, Davide Moccia, Elisabeth Michel, Olivier Péron, Hélène Howa, and Meryem Mojtahid
Biogeosciences, 17, 1933–1953, https://doi.org/10.5194/bg-17-1933-2020, https://doi.org/10.5194/bg-17-1933-2020, 2020
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This study focuses on benthic foraminiferal distribution in an Arctic fjord characterised by continuous sea ice production during winter and the consequent cascading of salty and corrosive waters (brine) to the seabed. The inner fjord is dominated by calcareous species (C). In the central deep basins, where brines are persistent, calcareous foraminifera are dissolved and agglutinated (A) dominate. The high A/C ratio is suggested as a proxy for brine persistence and sea ice production.
Johannes Hepp, Imke Kathrin Schäfer, Verena Lanny, Jörg Franke, Marcel Bliedtner, Kazimierz Rozanski, Bruno Glaser, Michael Zech, Timothy Ian Eglinton, and Roland Zech
Biogeosciences, 17, 741–756, https://doi.org/10.5194/bg-17-741-2020, https://doi.org/10.5194/bg-17-741-2020, 2020
Julian Struck, Marcel Bliedtner, Paul Strobel, Jens Schumacher, Enkhtuya Bazarradnaa, and Roland Zech
Biogeosciences, 17, 567–580, https://doi.org/10.5194/bg-17-567-2020, https://doi.org/10.5194/bg-17-567-2020, 2020
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We present leaf wax n-alkanes and their compound-specific (CS) δ13C isotopes from semi-arid and/or arid Mongolia to test their potential for paleoenvironmental reconstructions. Plants and topsoils were analysed and checked for climatic control. Chain-length variations are distinct between grasses and Caragana, which are not biased by climate. However CS δ13C is strongly correlated to climate, so n-alkanes and their CS δ13C show great potential for paleoenvironmental reconstruction in Mongolia.
Elena Lo Giudice Cappelli, Jessica Louise Clarke, Craig Smeaton, Keith Davidson, and William Edward Newns Austin
Biogeosciences, 16, 4183–4199, https://doi.org/10.5194/bg-16-4183-2019, https://doi.org/10.5194/bg-16-4183-2019, 2019
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Fjords are known sinks of organic carbon (OC); however, little is known about the long-term fate of the OC stored in these sediments. The reason for this knowledge gap is the post-depositional degradation of OC. This study uses benthic foraminifera (microorganisms with calcite shells) to discriminate between post-depositional OC degradation and actual OC burial and accumulation in fjordic sediments, as foraminifera would only preserve the latter information in their assemblage composition.
Sara K. E. Goulden, Naohiko Ohkouchi, Katherine H. Freeman, Yoshito Chikaraishi, Nanako O. Ogawa, Hisami Suga, Oliver Chadwick, and Benjamin Z. Houlton
Biogeosciences, 16, 3869–3882, https://doi.org/10.5194/bg-16-3869-2019, https://doi.org/10.5194/bg-16-3869-2019, 2019
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We investigate whether soil organic compounds preserve information about nitrogen availability to plants. We isolate chlorophyll degradation products in leaves, litter, and soil and explore possible species and climate effects on preservation and interpretation. We find that compound-specific nitrogen isotope measurements in soil have potential as a new tool to reconstruct changes in nitrogen cycling on a landscape over time, avoiding issues that have limited other proxies.
Nicolai Schleinkofer, Jacek Raddatz, André Freiwald, David Evans, Lydia Beuck, Andres Rüggeberg, and Volker Liebetrau
Biogeosciences, 16, 3565–3582, https://doi.org/10.5194/bg-16-3565-2019, https://doi.org/10.5194/bg-16-3565-2019, 2019
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In this study we tried to correlate Na / Ca ratios from cold-water corals with environmental parameters such as salinity, temperature and pH. We do not observe a correlation between Na / Ca ratios and seawater salinity, but we do observe a strong correlation with temperature. Na / Ca data from warm-water corals (Porites spp.) and bivalves (Mytilus edulis) support this correlation, indicating that similar controls on the incorporation of sodium exist in these aragonitic organisms.
Mattia Greco, Lukas Jonkers, Kerstin Kretschmer, Jelle Bijma, and Michal Kucera
Biogeosciences, 16, 3425–3437, https://doi.org/10.5194/bg-16-3425-2019, https://doi.org/10.5194/bg-16-3425-2019, 2019
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To be able to interpret the paleoecological signal contained in N. pachyderma's shells, its habitat depth must be known. Our investigation on 104 density profiles of this species from the Arctic and North Atlantic shows that specimens reside closer to the surface when sea-ice and/or surface chlorophyll concentrations are high. This is in contrast with previous investigations that pointed at the position of the deep chlorophyll maximum as the main driver of N. pachyderma vertical distribution.
Anna Mikis, Katharine R. Hendry, Jennifer Pike, Daniela N. Schmidt, Kirsty M. Edgar, Victoria Peck, Frank J. C. Peeters, Melanie J. Leng, Michael P. Meredith, Chloe L. C. Jones, Sharon Stammerjohn, and Hugh Ducklow
Biogeosciences, 16, 3267–3282, https://doi.org/10.5194/bg-16-3267-2019, https://doi.org/10.5194/bg-16-3267-2019, 2019
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Antarctic marine calcifying organisms are threatened by regional climate change and ocean acidification. Future projections of regional carbonate production are challenging due to the lack of historical data combined with complex climate variability. We present a 6-year record of flux, morphology and geochemistry of an Antarctic planktonic foraminifera, which shows that their growth is most sensitive to sea ice dynamics and is linked with the El Niño–Southern Oscillation.
Eunmi Park, Jens Hefter, Gerhard Fischer, Morten Hvitfeldt Iversen, Simon Ramondenc, Eva-Maria Nöthig, and Gesine Mollenhauer
Biogeosciences, 16, 2247–2268, https://doi.org/10.5194/bg-16-2247-2019, https://doi.org/10.5194/bg-16-2247-2019, 2019
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We analyzed GDGT-based proxy temperatures in the polar oceans. In the eastern Fram Strait (79° N), the nutrient distribution may determine the depth habit of Thaumarchaeota and thus the proxy temperature. In the Antarctic Polar Front (50° S), the contribution of Euryarchaeota or the nonlinear correlation between the proxy values and temperatures may cause the warm biases of the proxy temperatures relative to SSTs.
Marijke W. de Bar, Jenny E. Ullgren, Robert C. Thunnell, Stuart G. Wakeham, Geert-Jan A. Brummer, Jan-Berend W. Stuut, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 16, 1705–1727, https://doi.org/10.5194/bg-16-1705-2019, https://doi.org/10.5194/bg-16-1705-2019, 2019
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We analyzed sediment traps from the Cariaco Basin, the tropical Atlantic and the Mozambique Channel to evaluate seasonal imprints in the concentrations and fluxes of long-chain diols (LDIs), in addition to the long-chain diol index proxy (sea surface temperature proxy) and the diol index (upwelling indicator). Despite significant degradation, LDI-derived temperatures were very similar for the sediment traps and seafloor sediments, and corresponded to annual mean sea surface temperatures.
Jens Zinke, Juan P. D'Olivo, Christoph J. Gey, Malcolm T. McCulloch, J. Henrich Bruggemann, Janice M. Lough, and Mireille M. M. Guillaume
Biogeosciences, 16, 695–712, https://doi.org/10.5194/bg-16-695-2019, https://doi.org/10.5194/bg-16-695-2019, 2019
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Here we report seasonally resolved sea surface temperature (SST) reconstructions for the southern Mozambique Channel in the SW Indian Ocean, a region located along the thermohaline ocean surface circulation route, based on multi-trace-element temperature proxy records preserved in two Porites sp. coral cores for the past 42 years. Particularly, we show the suitability of both separate and combined Sr / Ca and Li / Mg proxies for improved multielement SST reconstructions.
Hilde Pracht, Brett Metcalfe, and Frank J. C. Peeters
Biogeosciences, 16, 643–661, https://doi.org/10.5194/bg-16-643-2019, https://doi.org/10.5194/bg-16-643-2019, 2019
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In palaeoceanography the shells of single-celled foraminifera are routinely used as proxies to reconstruct the temperature, salinity and circulation of the ocean in the past. Traditionally a number of specimens were pooled for a single stable isotope measurement; however, technical advances now mean that a single shell or chamber of a shell can be measured individually. Three different hypotheses regarding foraminiferal biology and ecology were tested using this approach.
Anna Jentzen, Dirk Nürnberg, Ed C. Hathorne, and Joachim Schönfeld
Biogeosciences, 15, 7077–7095, https://doi.org/10.5194/bg-15-7077-2018, https://doi.org/10.5194/bg-15-7077-2018, 2018
Shauna Ní Fhlaithearta, Christophe Fontanier, Frans Jorissen, Aurélia Mouret, Adriana Dueñas-Bohórquez, Pierre Anschutz, Mattias B. Fricker, Detlef Günther, Gert J. de Lange, and Gert-Jan Reichart
Biogeosciences, 15, 6315–6328, https://doi.org/10.5194/bg-15-6315-2018, https://doi.org/10.5194/bg-15-6315-2018, 2018
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This study looks at how foraminifera interact with their geochemical environment in the seabed. We focus on the incorporation of the trace metal manganese (Mn), with the aim of developing a tool to reconstruct past pore water profiles. Manganese concentrations in foraminifera are investigated relative to their ecological preferences and geochemical environment. This study demonstrates that Mn in foraminiferal tests is a promising tool to reconstruct oxygen conditions in the seabed.
Siobhan Williams, Walter Adey, Jochen Halfar, Andreas Kronz, Patrick Gagnon, David Bélanger, and Merinda Nash
Biogeosciences, 15, 5745–5759, https://doi.org/10.5194/bg-15-5745-2018, https://doi.org/10.5194/bg-15-5745-2018, 2018
Robert Frei, Cora Paulukat, Sylvie Bruggmann, and Robert M. Klaebe
Biogeosciences, 15, 4905–4922, https://doi.org/10.5194/bg-15-4905-2018, https://doi.org/10.5194/bg-15-4905-2018, 2018
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The reconstruction of paleo-redox conditions of seawater has the potential to link to climatic changes on land and therefore to contribute to our understanding of past climate change. The redox-sensitive chromium isotope system is applied to marine calcifiers in order to characterize isotope offsets that result from vital processes during calcification processes and which can be eventually used in fossil equivalents to reconstruct past seawater compositions.
Thomas M. DeCarlo, Michael Holcomb, and Malcolm T. McCulloch
Biogeosciences, 15, 2819–2834, https://doi.org/10.5194/bg-15-2819-2018, https://doi.org/10.5194/bg-15-2819-2018, 2018
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Understanding the mechanisms of coral calcification is limited by the isolation of the calcifying environment. The boron systematics (B / Ca and δ11B) of aragonite have recently been developed as a proxy for the carbonate chemistry of the calcifying fluid, but a variety of approaches have been utilized. We assess the available experimental B / Ca partitioning data and present a computer code for deriving calcifying fluid carbonate chemistry from the boron systematics of coral skeletons.
Manuel Bringué, Robert C. Thunell, Vera Pospelova, James L. Pinckney, Oscar E. Romero, and Eric J. Tappa
Biogeosciences, 15, 2325–2348, https://doi.org/10.5194/bg-15-2325-2018, https://doi.org/10.5194/bg-15-2325-2018, 2018
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We document 2.5 yr of dinoflagellate cyst production in the Cariaco Basin using a sediment trap record. Each species' production pattern is interpreted in the context of the physico-chemical (e.g., temperature, nutrients) and biological (other planktonic groups) environment. Most species respond positively to upwelling, but seem to be negatively impacted by an El Niño event with a 1-year lag. This work helps understanding dinoflagellate ecology and interpreting fossil assemblages in sediments.
Gabriella M. Weiss, Eva Y. Pfannerstill, Stefan Schouten, Jaap S. Sinninghe Damsté, and Marcel T. J. van der Meer
Biogeosciences, 14, 5693–5704, https://doi.org/10.5194/bg-14-5693-2017, https://doi.org/10.5194/bg-14-5693-2017, 2017
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Algal-derived compounds allow us to make assumptions about environmental conditions in the past. In order to better understand how organisms record environmental conditions, we grew microscopic marine algae at different light intensities, salinities, and alkalinities in a temperature-controlled environment. We determined how these environmental parameters affected specific algal-derived compounds, especially their relative deuterium content, which seems to be mainly affected by salinity.
S. Nemiah Ladd, Nathalie Dubois, and Carsten J. Schubert
Biogeosciences, 14, 3979–3994, https://doi.org/10.5194/bg-14-3979-2017, https://doi.org/10.5194/bg-14-3979-2017, 2017
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Hydrogen isotopes of lipids provide valuable information about microbial activity, climate, and environmental stress. We show that heavy hydrogen in fatty acids declines from spring to summer in a nutrient-rich and a nutrient-poor lake and that the effect is nearly 3 times as big in the former. This effect is likely a combination of increased biomass from algae, warmer temperatures, and higher algal growth rates.
Karoliina A. Koho, Lennart J. de Nooijer, Christophe Fontanier, Takashi Toyofuku, Kazumasa Oguri, Hiroshi Kitazato, and Gert-Jan Reichart
Biogeosciences, 14, 3067–3082, https://doi.org/10.5194/bg-14-3067-2017, https://doi.org/10.5194/bg-14-3067-2017, 2017
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Here we report Mn / Ca ratios in living benthic foraminifera from the NE Japan margin. The results show that the Mn incorporation directly reflects the environment where the foraminifera calcify. Foraminifera that live deeper in sediment, under greater redox stress, generally incorporate more Mn into their carbonate skeletons. As such, foraminifera living close to the Mn reduction zone in sediment appear promising tools for paleoceanographic reconstructions of sedimentary redox conditions.
Cited articles
Altabet, M.: Variations in nitrogen isotopic composition between sinking and suspended particles: implications for nitrogen cycling and particle transformation in the open ocean, Deep-Sea Res. Pt. I, 35, 535–554, https://doi.org/10.1016/0198-0149(88)90130-6, 1988.
Altabet, M. and Francois, R.: The use of nitrogen isotopic ratio for reconstruction of past changes in surface ocean nutrient utilization, in: Carbon Cycling in the Glacial Ocean: Constraints on the Ocean's Role in Global Change: Quantitative Approaches in Paleoceanography, Springer, 281–306, https://doi.org/10.1007/978-3-642-78737-9_12, 1994.
Altabet, M. A., Deuser, W. G., Honjo, S., and Stienen, C.: Seasonal and depth-related changes in the source of sinking particles in the North Atlantic, Nature, 354, 136, https://doi.org/10.1038/354136a0, 1991.
Anderson, O., Spindler, M., Bé, A., and Hemleben, C.: Trophic activity of planktonic foraminifera, J. Mar. Biol. Assoc. UK, 59, 791–799, https://doi.org/10.1017/S002531540004577X, 1979.
Anderson, O. R. and Be, A. W.: The ultrastructure of a planktonic foraminifer, Globigerinoides sacculifer (Brady), and its symbiotic dinoflagellates, J. Foramin. Res., 6, 1–21, https://doi.org/10.2113/gsjfr.6.1.1, 1976.
Auderset, A., Moretti, S., Taphorn, B., Ebner, P.-R., Kast, E., Wang, X. T., Schiebel, R., Sigman, D. M., Haug, G. H., and Martínez-García, A.: Enhanced ocean oxygenation during Cenozoic warm periods, Nature, 609, 77–82, https://doi.org/10.1038/s41586-022-05017-0, 2022.
Auderset, A., Fripiat, F. o., Creel, R. C., Oesch, L., Studer, A. S., Repschläger, J., Hathorne, E., Vonhof, H., Schiebel, R., and Gordon, L.: Sea Level Modulation of Atlantic Nitrogen Fixation Over Glacial Cycles, Paleoceanogr. Paleocl., 39, e2024PA004878, https://doi.org/10.1029/2024PA004878, 2024.
Auderset, A., Smart, S. M., Ryu, Y., Marconi, D., Ren, H. A., Heins, L., Vonhof, H., Schiebel, R., Repschläger, J., Vonhof, H. B., Schiebel, R., Sigman, D. M., Haug, G. H., and Martínez-García, A.: Species-specific foraminifera-bound nitrogen isotope and foraminiferal calcite oxygen and carbon isotope measurements from DSDP Site 516 in the South Atlantic over a glacial-interglacial cycle, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.979691, 2025.
Bijma, J., Faber, W. W., and Hemleben, C.: Temperature and salinity limits for growth and survival of some planktonic foraminifers in laboratory cultures, J. Foramin. Res., 20, 95–116, https://doi.org/10.2113/gsjfr.20.2.95, 1990.
Bijma, J., Hemleben, C., Huber, B. T., Erlenkeuser, H., and Kroon, D.: Experimental determination of the ontogenetic stable isotope variability in two morphotypes of Globigerinella siphonifera (d'Orbigny), Marine Micropaleontol., 35, 141–160, https://doi.org/10.1016/S0377-8398(98)00017-6, 1998.
Bird, C., Darling, K. F., Russell, A. D., Davis, C. V., Fehrenbacher, J., Free, A., Wyman, M., and Ngwenya, B. T.: Cyanobacterial endobionts within a major marine planktonic calcifier (Globigerina bulloides, Foraminifera) revealed by 16S rRNA metabarcoding, Biogeosciences, 14, 901–920, https://doi.org/10.5194/bg-14-901-2017, 2017.
Bird, C., LeKieffre, C., Jauffrais, T., Meibom, A., Geslin, E., Filipsson, H. L., Maire, O., Russell, A. D., and Fehrenbacher, J. S.: Heterotrophic Foraminifera Capable of Inorganic Nitrogen Assimilation, Front. Microbiol., 11, 3076, https://doi.org/10.3389/fmicb.2020.604979, 2020.
Boltovskoy, E.: Planktonic foraminifera as indicators of different water masses in the South Atlantic, Micropaleontology, 8, 403–408, https://doi.org/10.2307/1484531, 1962.
Brandes, J. A. and Devol, A. H.: A global marine-fixed nitrogen isotopic budget: Implications for Holocene nitrogen cycling, Global Biogeochem. Cycles, 16, 67-61–67-14, https://doi.org/10.1029/2001GB001856, 2002.
Breitenbach, S. F. and Bernasconi, S. M.: Carbon and oxygen isotope analysis of small carbonate samples (20 to 100 µg) with a GasBench II preparation device, Rapid Commun. Mass Sp., 25, 1910–1914, https://doi.org/10.1002/rcm.5052, 2011.
Broecker, W. S.: Glacial to interglacial changes in ocean chemistry, Prog. Oceanogr., 11, 151–197, https://doi.org/10.1016/0079-6611(82)90007-6, 1982.
Broecker, W. S. and Henderson, G. M.: The sequence of events surrounding Termination II and their implications for the cause of glacial-interglacial CO2 changes, Paleoceanography, 13, 352–364, https://doi.org/10.1029/98PA00920, 1998.
Brunelle, B. G., Sigman, D. M., Cook, M. S., Keigwin, L. D., Haug, G. H., Plessen, B., Schettler, G., and Jaccard, S. L.: Evidence from diatom-bound nitrogen isotopes for subarctic Pacific stratification during the last ice age and a link to North Pacific denitrification changes, Paleoceanography, 22, PA1215, https://doi.org/10.1029/2005PA001205, 2007.
Casciotti, K. L., Trull, T. W., Glover, D. M., and Davies, D.: Constraints on nitrogen cycling at the subtropical North Pacific Station ALOHA from isotopic measurements of nitrate and particulate nitrogen, Deep-Sea Res. Pt. II: Topical Studies in Oceanography, 55, 1661–1672, https://doi.org/10.1016/j.dsr2.2008.04.017, 2008.
Casciotti, K. L., Sigman, D. M., Hastings, M. G., Böhlke, J., and Hilkert, A.: Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method, Anal. Chem., 74, 4905–4912, https://doi.org/10.1021/ac020113w, 2002.
Cole, J. and Villacastin, C.: Sea surface temperature variability in the northern Benguela upwelling system, and implications for fisheries research, Int. J. Remote Sens., 21, 1597–1617, https://doi.org/10.1080/014311600209922, 2000.
Costa, K. M., McManus, J. F., Anderson, R. F., Ren, H., Sigman, D. M., Winckler, G., Fleisher, M. Q., Marcantonio, F., and Ravelo, A. C.: No iron fertilization in the equatorial Pacific Ocean during the last ice age, Nature, 529, 519–522, https://doi.org/10.1038/nature16453, 2016.
Cullen, J. J., Franks, P. J., Karl, D. M., and Longhurst, A.: Physical influences on marine ecosystem dynamics, The Sea, 12, 297–336, 2002.
Davy, S. K., Allemand, D., and Weis Virginia, M.: Cell Biology of Cnidarian-Dinoflagellate Symbiosis, Microbiol. Mol. Biol. R., 76, 229–261, https://doi.org/10.1128/mmbr.05014-11, 2012.
DeNiro, M. J.: You are what you eat (plus a few ‰): the carbon isotope cycle in food chains, Geological Society of America Abstracts with Programs, Geological Society of America Abstracts with Programs, 8, 834–835, 1976.
DeNiro, M. J. and Epstein, S.: Influence of diet on the distribution of nitrogen isotopes in animals, Geochim. Cosmochim. Ac., 45, 341–351, https://doi.org/10.1016/0016-7037(81)90244-1, 1981.
Deuser, W.: Seasonal variations in isotopic composition and deep-water fluxes of the tests of perennially abundant planktonic foraminifera of the Sargasso Sea; results from sediment-trap collections and their paleoceanographic significance, J. Foramin. Res., 17, 14–27, 1987.
Deutsch, C., Sigman, D. M., Thunell, R. C., Meckler, A. N., and Haug, G. H.: Isotopic constraints on glacial/interglacial changes in the oceanic nitrogen budget, Global Biogeochem. Cycles, 18, GB4012, https://doi.org/10.1029/2003GB002189, 2004.
D'Hondt, S., Zachos, J. C., and Schultz, G.: Stable isotopic signals and photosymbiosis in late Paleocene planktic foraminifera, Paleobiology, 20, 391–406, https://doi.org/10.1017/S0094837300012847, 1994.
Dugdale, R. C. and Goering, J. J.: Uptake of new and regenerated forms of nitrogen in primary productivity, Limnol. Oceanogr., 12, 196–206, https://doi.org/10.4319/lo.1967.12.2.0196, 1967.
Edgar, K. M., Bohaty, S., Gibbs, S., Sexton, P., Norris, R., and Wilson, P.: Symbiont `bleaching'in planktic foraminifera during the Middle Eocene Climatic Optimum, Geology, 41, 15–18, https://doi.org/10.1130/G33388.1, 2013.
Eppley, R. W. and Peterson, B. J.: Particulate organic matter flux and planktonic new production in the deep ocean, Nature, 282, 677–680, https://doi.org/10.1038/282677a0, 1979.
Ezard, T. H., Edgar, K. M., and Hull, P. M.: Environmental and biological controls on size-specific δ13C and δ18O in recent planktonic foraminifera, Paleoceanography, 30, 151–173, https://doi.org/10.1002/2014PA002735, 2015.
Faber, W., Anderson, O., Lindsey, J., and Caron, D.: Algal-foraminiferal symbiosis in the planktonic foraminifer Globigerinella aequilateralia; I, Occurrence and stability of two mutually exclusive chrysophyte endosymbionts and their ultrastructure, J. Foramin. Res., 18, 334–343, https://doi.org/10.2113/gsjfr.18.4.334, 1988.
Faber, W., Anderson, O., and Caron, D.: Algal-foraminiferal symbiosis in the planktonic foraminifer Globigerinella aequilateralis; II, Effects of two symbiont species on foraminiferal growth and longevity, J. Foramin. Res., 19, 185–193, https://doi.org/10.2113/gsjfr.19.3.185, 1989.
Fairbanks, R. G. and Wiebe, P. H.: Foraminifera and chlorophyll maximum: vertical distribution, seasonal succession, and paleoceanographic significance, Science, 209, 1524–1526, 1980.
Falkowski, P. G.: Evolution of the nitrogen cycle and its influence on the biological sequestration of CO2 in the ocean, Nature, 387, 272, https://doi.org/10.1038/387272a0, 1997.
Fawcett, S. E., Lomas, M. W., Casey, J. R., Ward, B. B., and Sigman, D. M.: Assimilation of upwelled nitrate by small eukaryotes in the Sargasso Sea, Nat. Geosci., 4, 717–722, https://doi.org/10.1038/ngeo1265, 2011.
Fawcett, S. E., Ward, B. B., Lomas, M. W., and Sigman, D. M.: Vertical decoupling of nitrate assimilation and nitrification in the Sargasso Sea, Deep-Sea Res. Pt. I, 103, 64–72, https://doi.org/10.1016/j.dsr.2015.05.004, 2015.
Febvre-Chevalier, C.: Constitution ultrastructurale de Globigerina bulloides d'Orbigny, 1826 (Rhizopoda-Foraminifera), Protistologica, 7, 311–324, 1971.
Fripiat, F., Martínez-García, A., Marconi, D., Fawcett, S. E., Kopf, S. H., Luu, V. H., Rafter, P. A., Zhang, R., Sigman, D. M., and Haug, G. H.: Nitrogen isotopic constraints on nutrient transport to the upper ocean, Nat. Geosci., 14, 855–861, https://doi.org/10.1038/s41561-021-00836-8, 2021.
Galbraith, E. D., Kienast, M., Albuquerque, A. L., Altabet, M. A., Batista, F., Bianchi, D., Calvert, S. E., Contreras, S., Crosta, X., and De Pol-Holz, R.: The acceleration of oceanic denitrification during deglacial warming, Nat. Geosci., 6, 579, https://doi.org/10.1038/ngeo1832, 2013.
Garcia, H. E., Locarnini, R. A., Boyer, T. P., Antonov, J. I., Baranova, O. K., Zweng, M. M., Reagan, J. R., and Johnson, D. R.: World Ocean Atlas 2013, Volume 4: Dissolved Inorganic Nutrients (phosphate, nitrate, silicate), S. Levitus, edited by: Mishonov, A., NOAA Atlas NESDIS, 76, 25 pp., 2014.
Gast, R. and Caron, D.: Molecular phylogeny of symbiotic dinoflagellates from planktonic foraminifera and radiolaria, Mol. Biol. Evol., 13, 1192–1197, https://doi.org/10.1093/oxfordjournals.molbev.a025684, 1996.
Gast, R. J., McDonnell, T. A., and Caron, D. A.: srDna-based taxonomic affinities of algal symbionts from a planktonic foraminifer and a solitary radiolarian, J. Phycol., 36, 172–177, https://doi.org/10.1046/j.1529-8817.2000.99133.x, 2000.
Gastrich, M. D.: Ultrastructure of a new intracellular symbiotic alga found within planktonic foraminifera, J. Phycol., 23, 623–632, https://doi.org/10.1111/j.1529-8817.1987.tb04215.x, 1987.
Granger, J. and Sigman, D. M.: Removal of nitrite with sulfamic acid for nitrate N and O isotope analysis with the denitrifier method, Rapid Commun. Mass Sp., 23, 3753–3762, https://doi.org/10.1002/rcm.4307, 2009.
Granger, R., Smart, S. M., Foreman, A., Auderset, A., Campbell, E. C., Marshall, T. A., Haug, G. H., Sigman, D. M., Martínez-García, A., and Fawcett, S. E.: Tracking Agulhas Leakage in the South Atlantic Using Modern Planktic Foraminifera Nitrogen Isotopes, Geochem. Geophys. Geosyst., 25, e2023GC011190, https://doi.org/10.1029/2023GC011190, 2024.
Gruber, N. and Sarmiento, J. L.: Global patterns of marine nitrogen fixation and denitrification, Global Biogeochem. Cycles, 11, 235–266, https://doi.org/10.1029/97GB00077, 1997.
Hallock, P.: Algal symbiosis: a mathematical analysis, Marine Biol., 62, 249–255, https://doi.org/10.1007/BF00397691, 1981.
Hannides, C. C. S., Popp, B. N., Choy, C. A., and Drazen, J. C.: Midwater zooplankton and suspended particle dynamics in the North Pacific Subtropical Gyre: A stable isotope perspective, Limnol. Oceanogr., 58, 1931–1946, https://doi.org/10.4319/lo.2013.58.6.1931, 2013.
Harms, N. C., Lahajnar, N., Gaye, B., Rixen, T., Dähnke, K., Ankele, M., Schwarz-Schampera, U., and Emeis, K.-C.: Nutrient distribution and nitrogen and oxygen isotopic composition of nitrate in water masses of the subtropical southern Indian Ocean, Biogeosciences, 16, 2715–2732, https://doi.org/10.5194/bg-16-2715-2019, 2019.
Hemleben, C., Spindler, M., Breitinger, I., and Deuser, W. G.: Field and laboratory studies on the ontogeny and ecology of some globorotaliid species from the Sargasso Sea off Bermuda, J. Foramin. Res., 15, 254–272, https://doi.org/10.2113/gsjfr.15.4.254, 1985.
Hemleben, C., Spindler, M., and Anderson, O. R.: Modern planktonic foraminifera, Springer Science & Business Media, https://doi.org/10.1007/978-1-4612-3544-6, 1989.
Hess, A. V., Auderset, A., Rosenthal, Y., Miller, K. G., Zhou, X., Sigman, D. M., and Martínez-García, A.: A well-oxygenated eastern tropical Pacific during the warm Miocene, Nature, 619, 521–525, https://doi.org/10.1038/s41586-023-06104-6, 2023.
Hohmann-Marriott, M. F. and Blankenship, R. E.: Evolution of photosynthesis, Annu. Rev. Plant Biol., 62, 515–548, https://doi.org/10.1146/annurev-arplant-042110-103811, 2011.
Hupp, B. N., Kelly, D. C., Zachos, J. C., and Bralower, T. J.: Effects of size-dependent sediment mixing on deep-sea records of the Paleocene-Eocene Thermal Maximum, Geology, 47, 749–752, https://doi.org/10.1130/G46042.1, 2019.
Hutto, L., Weller, R., Fratantoni, D., Lord, J., Kemp, J., Lund, J., Brambilla, E., and Bigorre, S.: CLIVAR Mode Water Dynamics Experiment (CLIMODE) fall 2005, R/V Oceanus voyage 419, November 9, 2005 – November 27, 2005, Woods Hole Oceanographic Institution, https://doi.org/10.1575/1912/1073, 2006.
Jonkers, L. and Kučera, M.: Global analysis of seasonality in the shell flux of extant planktonic Foraminifera, Biogeosciences, 12, 2207–2226, https://doi.org/10.5194/bg-12-2207-2015, 2015.
Kast, E. R., Stolper, D. A., Auderset, A., Higgins, J. A., Ren, H., Wang, X. T., Martínez-García, A., Haug, G. H., and Sigman, D. M.: Nitrogen isotope evidence for expanded ocean suboxia in the early Cenozoic, Science, 364, 386–389, https://doi.org/10.1126/science.aau5784, 2019.
Kast, E. R., Griffiths, M. L., Kim, S. L., Rao, Z. C., Shimada, K., Becker, M. A., Maisch, H. M., Eagle, R. A., Clarke, C. A., and Neumann, A. N.: Cenozoic megatooth sharks occupied extremely high trophic positions, Sci. Adv., 8, eabl6529, https://doi.org/10.1126/sciadv.abl6529, 2022.
Knapp, A. N., Sigman, D. M., and Lipschultz, F.: N isotopic composition of dissolved organic nitrogen and nitrate at the Bermuda Atlantic Time-series Study site, Global Biogeochem. Cycles, 19, GB1018, https://doi.org/10.1029/2004GB002320, 2005.
Knapp, A. N., DiFiore, P. J., Deutsch, C., Sigman, D. M., and Lipschultz, F.: Nitrate isotopic composition between Bermuda and Puerto Rico: Implications for N2 fixation in the Atlantic Ocean, Global Biogeochem. Cycles, 22, GB3014, https://doi.org/10.1029/2007GB003107, 2008.
Kretschmer, K., Jonkers, L., Kucera, M., and Schulz, M.: Modeling seasonal and vertical habitats of planktonic foraminifera on a global scale, Biogeosciences, 15, 4405–4429, https://doi.org/10.5194/bg-15-4405-2018, 2018.
Kroopnick, P.: The distribution of 13C of ΣCO2 in the world oceans, Deep-Sea Res. Pt. I, 32, 57–84, https://doi.org/10.1016/0198-0149(85)90017-2, 1985.
Lee, J. J., Freudenthal, H. D., Kossoy, V., and Bé, A.: Cytological observations on two planktonic foraminifera, Globigerina bulloides d'Orbigny, 1826, and Globigerinoides ruber (d'Orbigny, 1839) Cushman, 1927, J. Protozool., 12, 531–542, https://doi.org/10.1111/j.1550-7408.1965.tb03253.x, 1965.
LeKieffre, C., Spero, H. J., Fehrenbacher, J. S., Russell, A. D., Ren, H., Geslin, E., and Meibom, A.: Ammonium is the preferred source of nitrogen for planktonic foraminifer and their dinoflagellate symbionts, P. Roy. Soc. B, 287, 20200620, https://doi.org/10.1098/rspb.2020.0620, 2020.
Li, D.-W., Xiang, R., Wu, Q., and Kao, S.-J.: Planktic foraminifera-bound organic nitrogen isotopic composition in contemporary water column and sediment trap, Deep-Sea Res. Pt. I, 143, 28–34, https://doi.org/10.1016/j.dsr.2018.12.003, 2019.
Lisiecki, L. E. and Raymo, M. E.: A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records, Paleoceanography, 20, PA1003, https://doi.org/10.1029/2004PA001071, 2005.
Lisiecki, L. E. and Stern, J. V.: Regional and global benthic δ18O stacks for the last glacial cycle, Paleoceanography, 31, 1368–1394, https://doi.org/10.1002/2016PA003002, 2016.
Liu, K.-K., Su, M.-J., Hsueh, C.-R., and Gong, G.-C.: The nitrogen isotopic composition of nitrate in the Kuroshio Water northeast of Taiwan: Evidence for nitrogen fixation as a source of isotopically light nitrate, Marine Chem., 54, 273–292, https://doi.org/10.1016/0304-4203(96)00034-5, 1996.
Lomas, M., Bates, N., Johnson, R., Knap, A., Steinberg, D., and Carlson, C.: Two decades and counting: 24-years of sustained open ocean biogeochemical measurements in the Sargasso Sea, Deep-Sea Res. Pt. II, 93, 16–32, https://doi.org/10.1016/j.dsr2.2013.01.008, 2013.
Lueders-Dumont, J. A., Wang, X. T., Jensen, O. P., Sigman, D. M., and Ward, B. B.: Nitrogen isotopic analysis of carbonate-bound organic matter in modern and fossil fish otoliths, Geochim. Cosmochim. Ac., 224, 200–222, https://doi.org/10.1016/j.gca.2018.01.001, 2018.
Marconi, D., Weigand, M. A., Rafter, P. A., McIlvin, M. R., Forbes, M., Casciotti, K. L., and Sigman, D. M.: Nitrate isotope distributions on the US GEOTRACES North Atlantic cross-basin section: Signals of polar nitrate sources and low latitude nitrogen cycling, Marine Chem., 177, 143–156, https://doi.org/10.1016/j.marchem.2015.06.007, 2015.
Marconi, D., Sigman, D. M., Casciotti, K. L., Campbell, E. C., Alexandra Weigand, M., Fawcett, S. E., Knapp, A. N., Rafter, P. A., Ward, B. B., and Haug, G. H.: Tropical dominance of N2 fixation in the North Atlantic Ocean, Global Biogeochem. Cycles, 31, 1608–1623, https://doi.org/10.1002/2016GB005613, 2017.
Marconi, D., Sigman, D. M., Casciotti, K. L., Lawrence, R. M., Wang, W., Oleynik, S., and Martínez-García, A.: Distinguishing the isotopic signals of nitrate assimilation and denitrification along meridional Pacific section US GEOTRACES GP15, ESS Open Archive, 12 November 2024..
Marshall, T., Granger, J., Casciotti, K. L., Dähnke, K., Emeis, K.-C., Marconi, D., McIlvin, M. R., Noble, A. E., Saito, M. A., and Sigman, D. M.: The Angola Gyre is a hotspot of dinitrogen fixation in the South Atlantic Ocean, Commun. Earth Environ., 3, 151, https://doi.org/10.1038/s43247-022-00474-x, 2022.
Marshall, T. A., Sigman, D. M., Beal, L. M., Foreman, A., Martínez-García, A., Blain, S., Campbell, E., Fripiat, F., Granger, R., and Harris, E.: The Agulhas Current transports signals of local and remote Indian Ocean nitrogen cycling, J. Geophys. Res.-Oceans, 128, e2022JC019413, https://doi.org/10.1029/2022JC019413, 2023.
Martínez-García, A., Sigman, D. M., Ren, H., Anderson, R. F., Straub, M., Hodell, D. A., Jaccard, S. L., Eglinton, T. I., and Haug, G. H.: Iron fertilization of the Subantarctic Ocean during the last ice age, Science, 343, 1347–1350, https://doi.org/10.1126/science.1246848, 2014.
Martínez-García, A., Jung, J., Ai, X. E., Sigman, D. M., Auderset, A., Duprey, N. N., Foreman, A., Fripiat, F., Leichliter, J., and Lüdecke, T.: Laboratory assessment of the impact of chemical oxidation, mineral dissolution, and heating on the nitrogen isotopic composition of fossil-bound organic matter, Geochem. Geophys. Geosyst., 23, e2022GC010396, https://doi.org/10.1029/2022GC010396, 2022.
McElroy, M. B.: Marine biological controls on atmospheric CO2 and climate, Nature, 302, 328–329, https://doi.org/10.1038/302328a0, 1983.
Meckler, A. N., Ren, H., Sigman, D. M., Gruber, N., Plessen, B., Schubert, C. J., and Haug, G. H.: Deglacial nitrogen isotope changes in the Gulf of Mexico: Evidence from bulk sedimentary and foraminifera-bound nitrogen in Orca Basin sediments, Paleoceanography, 26, PA4216, https://doi.org/10.1029/2011PA002156, 2011.
Minagawa, M. and Wada, E.: Stepwise enrichment of 15N along food chains: further evidence and the relation between δ15N and animal age, Geochim. Cosmochim. Ac., 48, 1135–1140, https://doi.org/10.1016/0016-7037(84)90204-7, 1984.
Mino, Y., Saino, T., Suzuki, K., and Marañón, E.: Isotopic composition of suspended particulate nitrogen (δ15Nsus) in surface waters of the Atlantic Ocean from 50° N to 50° S, Global Biogeochem. Cycles, 16, 7-1–7-9, https://doi.org/10.1029/2001GB001635, 2002.
Mintenbeck, K., Jacob, U., Knust, R., Arntz, W., and Brey, T.: Depth-dependence in stable isotope ratio δ15N of benthic POM consumers: the role of particle dynamics and organism trophic guild, Deep-Sea Res. Pt. I, 54, 1015–1023, https://doi.org/10.1016/j.dsr.2007.03.005, 2007.
Möbius, J.: Isotope fractionation during nitrogen remineralization (ammonification): Implications for nitrogen isotope biogeochemistry, Geochim. Cosmochim. Ac., 105, 422–432, https://doi.org/10.1016/j.gca.2012.11.048, 2013.
Montoya, J. P., Carpenter, E. J., and Capone, D. G.: Nitrogen fixation and nitrogen isotope abundances in zooplankton of the oligotrophic North Atlantic, Limnol. Oceanogr., 47, 1617–1628, https://doi.org/10.4319/lo.2002.47.6.1617, 2002.
Moretti, S., Duprey, N. N., Foreman, A. D., Arns, A., Brömme, S., Jung, J., Ai, X. E., Auderset, A., Bieler, A. L., and Eck, C.: Analytical improvements and assessment of long-term performance of the oxidation–denitrifier method, Rapid Commun. Mass Sp., 38, e9650, https://doi.org/10.1002/rcm.9650, 2024.
Mortyn, P. G. and Charles, C. D.: Planktonic foraminiferal depth habitat and δ18O calibrations: Plankton tow results from the Atlantic sector of the Southern Ocean, Paleoceanography, 18, 1037, https://doi.org/10.1029/2001PA000637, 2003.
Mulitza, S., Dürkoop, A., Hale, W., Wefer, G., and Stefan Niebler, H.: Planktonic foraminifera as recorders of past surface-water stratification, Geology, 25, 335–338, https://doi.org/10.1130/0091-7613(1997)025<0335:PFAROP>2.3.CO;2, 1997.
Ninnemann, U. S. and Charles, C. D.: Regional differences in Quaternary Subantarctic nutrient cycling: Link to intermediate and deep water ventilation, Paleoceanography, 12, 560–567, https://doi.org/10.1029/97PA01032, 1997.
Norris, R. D.: Symbiosis as an evolutionary innovation in the radiation of Paleocene planktic foraminifera, Paleobiology, 22, 461–480, https://doi.org/10.1017/S0094837300016468, 1996.
Norris, R. D.: Recognition and macroevolutionary significance of photosymbiosis in molluscs, corals, and foraminifera, The Paleontological Society Papers, 4, 68–100, https://doi.org/10.1017/S1089332600000401, 1998.
Paillard, D., Labeyrie, L., and Yiou, P.: Macintosh program performs time-series analysis, Eos, Transactions American Geophysical Union, 77, 379–379, 1996.
Peeters, F. J., Acheson, R., Brummer, G.-J. A., De Ruijter, W. P., Schneider, R. R., Ganssen, G. M., Ufkes, E., and Kroon, D.: Vigorous exchange between the Indian and Atlantic oceans at the end of the past five glacial periods, Nature, 430, 661–665, https://doi.org/10.1038/nature02785, 2004.
Peterson, R. G. and Stramma, L.: Upper-level circulation in the South Atlantic Ocean, Prog. Oceanogr., 26, 1–73, https://doi.org/10.1016/0079-6611(91)90006-8, 1991.
Piña-Ochoa, E., Høgslund, S., Geslin, E., Cedhagen, T., Revsbech, N. P., Nielsen, L. P., Schweizer, M., Jorissen, F., Rysgaard, S., and Risgaard-Petersen, N.: Widespread occurrence of nitrate storage and denitrification among Foraminifera and Gromiida, P. Natl. Acad. Sci. USA, 107, 1148–1153, https://doi.org/10.1073/pnas.0908440107, 2010.
Rashid, H. and Boyle, E. A.: Mixed-layer deepening during Heinrich events: A multi-planktonic foraminiferal δ18O approach, Science, 318, 439–441, https://doi.org/10.1126/science.1146138, 2007.
Ravelo, A. and Fairbanks, R.: Oxygen isotopic composition of multiple species of planktonic foraminifera: Recorders of the modern photic zone temperature gradient, Paleoceanography, 7, 815–831, 1992.
Rebotim, A., Voelker, A. H. L., Jonkers, L., Waniek, J. J., Meggers, H., Schiebel, R., Fraile, I., Schulz, M., and Kucera, M.: Factors controlling the depth habitat of planktonic foraminifera in the subtropical eastern North Atlantic, Biogeosciences, 14, 827–859, https://doi.org/10.5194/bg-14-827-2017, 2017.
Reid, J. L., Nowlin Jr, W. D., and Patzert, W. C.: On the characteristics and circulation of the southwestern Atlantic Ocean, J. Phys. Oceanogr., 7, 62–91, https://doi.org/10.1175/1520-0485(1977)007<0062:OTCACO>2.0.CO;2, 1977.
Ren, H., Sigman, D., Meckler, A., Plessen, B., Robinson, R., Rosenthal, Y., and Haug, G.: Foraminiferal isotope evidence of reduced nitrogen fixation in the ice age Atlantic Ocean, Science, 323, 244–248, https://doi.org/10.1126/science.1165787, 2009.
Ren, H., Sigman, D. M., Chen, M. T., and Kao, S. J.: Elevated foraminifera-bound nitrogen isotopic composition during the last ice age in the South China Sea and its global and regional implications, Global Biogeochem. Cycles, 26, GB1031, https://doi.org/10.1029/2010GB004020, 2012a.
Ren, H., Sigman, D. M., Thunell, R. C., and Prokopenko, M. G.: Nitrogen isotopic composition of planktonic foraminifera from the modern ocean and recent sediments, Limnol. Oceanogr., 57, 1011–1024, https://doi.org/10.4319/lo.2012.57.4.1011, 2012b.
Ren, H., Studer, A. S., Serno, S., Sigman, D. M., Winckler, G., Anderson, R. F., Oleynik, S., Gersonde, R., and Haug, G. H.: Glacial-to-interglacial changes in nitrate supply and consumption in the subarctic North Pacific from microfossil-bound N isotopes at two trophic levels, Paleoceanography, 30, 1217–1232, https://doi.org/10.1002/2014PA002765, 2015.
Ren, H., Sigman, D. M., Martínez-García, A., Anderson, R. F., Chen, M.-T., Ravelo, A. C., Straub, M., Wong, G. T., and Haug, G. H.: Impact of glacial/interglacial sea level change on the ocean nitrogen cycle, P. Natl. Acad. Sci. USA, 114, E6759–E6766, https://doi.org/10.1073/pnas.1701315114, 2017.
Repschläger, J., Auderset, A., Blanz, T., Bremer, K., Böttner, C., Eich, C., Kausch, T., Keigwin, L. D., Keul, N., and Kiefer, J.: North Atlantic Subtropical Gyre Azores Front (NASGAF), Cruise No. MSM58/1, September 10, 2016-October 7, 2016, Reykjavik (Iceland)-Ponta Delgada (Azores, Portugal), Gutachterpanel Forschungsschiffe, https://doi.org/10.2312/cr_msm58_1, 2018.
Reynolds, C. E., Richey, J. N., Fehrenbacher, J. S., Rosenheim, B. E., and Spero, H. J.: Environmental controls on the geochemistry of Globorotalia truncatulinoides in the Gulf of Mexico: Implications for paleoceanographic reconstructions, Marine Micropaleontol., 142, 92–104, https://doi.org/10.1016/j.marmicro.2018.05.006, 2018.
Robinson, R. S., Brunelle, B. G., and Sigman, D. M.: Revisiting nutrient utilization in the glacial Antarctic: Evidence from a new method for diatom-bound N isotopic analysis, Paleoceanography, 19, PA3001, https://doi.org/10.1029/2003PA000996, 2004.
Robinson, R. S., Kienast, M., Luiza Albuquerque, A., Altabet, M., Contreras, S., De Pol Holz, R., Dubois, N., Francois, R., Galbraith, E., and Hsu, T. C.: A review of nitrogen isotopic alteration in marine sediments, Paleoceanography, 27, PA4203, https://doi.org/10.1029/2012PA002321, 2012.
Salmon, K. H., Anand, P., Sexton, P. F., and Conte, M.: Upper ocean mixing controls the seasonality of planktonic foraminifer fluxes and associated strength of the carbonate pump in the oligotrophic North Atlantic, Biogeosciences, 12, 223–235, https://doi.org/10.5194/bg-12-223-2015, 2015.
Sarmiento, J. L. and Gruber, N.: Ocean Biogeochemical Dynamics, Princeton University Press, https://doi.org/10.1515/9781400849079, 2006.
Schiebel, R. and Hemleben, C.: Planktic foraminifers in the modern ocean, Springer, https://doi.org/10.1007/978-3-662-50297-6, 2017.
Schiebel, R., Hiller, B., and Hemleben, C.: Impacts of storms on recent planktic foraminiferal test production and CaCO3 flux in the North Atlantic at 47° N, 20° W (JGOFS), Marine Micropaleontol., 26, 115–129, https://doi.org/10.1016/0377-8398(95)00035-6, 1995.
Schiebel, R., Waniek, J., Bork, M., and Hemleben, C.: Planktic foraminiferal production stimulated by chlorophyll redistribution and entrainment of nutrients, Deep-Sea Res. Pt. I, 48, 721–740, https://doi.org/10.1016/S0967-0637(00)00065-0, 2001.
Schiebel, R., Schmuker, B., Alves, M., and Hemleben, C.: Tracking the Recent and late Pleistocene Azores front by the distribution of planktic foraminifers, J. Marine Syst., 37, 213–227, https://doi.org/10.1016/S0924-7963(02)00203-8, 2002.
Schiebel, R., Smart, S. M., Jentzen, A., Jonkers, L., Morard, R., Meilland, J., Michel, E., Coxall, H. K., Hull, P. M., and de Garidel-Thoron, T.: Advances in planktonic foraminifer research: New perspectives for paleoceanography, Revue de Micropaleontologie, 61, 113–138, https://doi.org/10.1016/j.revmic.2018.10.001, 2018.
Schlitzer, R.: Data analysis and visualization with Ocean Data View, CMOS Bulletin SCMO, 43, 9–13, 2015.
Schmid, C., Siedler, G., and Zenk, W.: Dynamics of intermediate water circulation in the subtropical South Atlantic, J. Phys. Oceanogr., 30, 3191–3211, https://doi.org/10.1175/1520-0485(2000)030<3191:DOIWCI>2.0.CO;2, 2000.
Schmidt, D. N., Renaud, S., Bollmann, J., Schiebel, R., and Thierstein, H. R.: Size distribution of Holocene planktic foraminifer assemblages: biogeography, ecology and adaptation, Marine Micropaleontol., 50, 319–338, https://doi.org/10.1016/S0377-8398(03)00098-7, 2004.
Schmitz Jr., W. J. and McCartney, M. S.: On the North Atlantic Circulation, Rev. Geophys., 31, 29–49, https://doi.org/10.1029/92RG02583, 1993.
Schubert, C. J. and Calvert, S. E.: Nitrogen and carbon isotopic composition of marine and terrestrial organic matter in Arctic Ocean sediments:: implications for nutrient utilization and organic matter composition, Deep-Sea Res. Pt. I, 48, 789–810, https://doi.org/10.1016/S0967-0637(00)00069-8, 2001.
Shaw, J. O., D'haenens, S., Thomas, E., Norris, R. D., Lyman, J. A., Bornemann, A., and Hull, P. M.: Photosymbiosis in planktonic foraminifera across the Paleocene–Eocene thermal maximum, Paleobiology, 47, 632–647, https://doi.org/10.1017/pab.2021.7, 2021.
Siccha, M., Morard, R., and Kucera, M.: Processed multinet CTD data from METEOR cruise M124, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.895426, 2018.
Sigman, D., Casciotti, K., Andreani, M., Barford, C., Galanter, M., and Böhlke, J.: A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater, Anal. Chem., 73, 4145–4153, https://doi.org/10.1021/ac010088e, 2001.
Sigman, D. M., Altabet, M. A., Francois, R., McCorkle, D. C., and Gaillard, J. F.: The isotopic composition of diatom-bound nitrogen in Southern Ocean sediments, Paleoceanography, 14, 118–134, https://doi.org/10.1029/1998PA900018, 1999.
Sigman, D. M., Altabet, M., McCorkle, D., Francois, R., and Fischer, G.: The δ15N of nitrate in the Southern Ocean: Nitrogen cycling and circulation in the ocean interior, J. Geophys. Res.-Oceans, 105, 19599–19614, https://doi.org/10.1029/2000JC000265, 2000.
Silfer, J., Engel, M., and Macko, S.: Kinetic fractionation of stable carbon and nitrogen isotopes during peptide bond hydrolysis: experimental evidence and geochemical implications, Chem. Geol.: Isotope Geoscience section, 101, 211–221, https://doi.org/10.1016/0009-2541(92)90003-N, 1992.
Smart, S. M., Fawcett, S. E., Thomalla, S. J., Weigand, M. A., Reason, C. J., and Sigman, D. M.: Isotopic evidence for nitrification in the Antarctic winter mixed layer, Global Biogeochem. Cycles, 29, 427–445, https://doi.org/10.1002/2014GB005013, 2015.
Smart, S. M., Ren, H., Fawcett, S. E., Schiebel, R., Conte, M., Rafter, P. A., Ellis, K. K., Weigand, M. A., Oleynik, S., Haug, G. H., and Sigman, D. M.: Ground-truthing the planktic foraminifer-bound nitrogen isotope paleo-proxy in the Sargasso Sea, Geochim. Cosmochim. Ac., 235, 463–482, https://doi.org/10.1016/j.gca.2018.05.023, 2018.
Smart, S. M., Fawcett, S. E., Ren, H., Schiebel, R., Tompkins, E. M., Martínez-García, A., Stirnimann, L., Roychoudhury, A., Haug, G. H., and Sigman, D. M.: The nitrogen isotopic composition of tissue and shell-bound organic matter of planktic foraminifera in Southern Ocean surface waters, Geochem. Geophys. Geosyst., 21, e2019GC008440, https://doi.org/10.1029/2019GC008440, 2020.
Spero, H. and Williams, D.: Opening the carbon isotope “vital effect” black box 1. Seasonal temperatures in the euphotic zone, Paleoceanography, 4, 593–601, 1989.
Spero, H. J. and DeNiro, M. J.: The influence of symbiont photosynthesis on the δ18O and δ13C values of planktonic foraminiferal shell calcite, Symbiosis, 4, 213–228, 1987.
Spero, H. J. and Lea, D. W.: Experimental determination of stable isotope variability in Globigerina bulloides: implications for paleoceanographic reconstructions, Marine Micropaleontol., 28, 231–246, https://doi.org/10.1016/0377-8398(96)00003-5, 1996.
Spero, H. J., Lerche, I., and Williams, D. F.: Opening the carbon isotope “vital effect” black box, 2, Quantitative model for interpreting foraminiferal carbon isotope data, Paleoceanography, 6, 639–655, https://doi.org/10.1029/91PA02022, 1991.
Spero, H. J., Bijma, J., Lea, D. W., and Bemis, B. E.: Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes, Nature, 390, 497–500, https://doi.org/10.1038/37333, 1997.
Spindler, M., Hemleben, C., Salomons, J., and Smit, L.: Feeding behavior of some planktonic foraminifers in laboratory cultures, J. Foramin. Res., 14, 237–249, https://doi.org/10.2113/gsjfr.14.4.237, 1984.
Steinberg, D. K., Carlson, C. A., Bates, N. R., Johnson, R. J., Michaels, A. F., and Knap, A. H.: Overview of the US JGOFS Bermuda Atlantic Time-series Study (BATS): a decade-scale look at ocean biology and biogeochemistry, Deep-Sea Res. Pt. II, 48, 1405–1447, https://doi.org/10.1016/S0967-0645(00)00148-X, 2001.
Stramma, L.: Geostrophic transport of the South Equatorial Current in the Atlantic, J. Marine Res., 49, 281–294, 1991.
Straub, M., Sigman, D. M., Ren, H., Martínez-García, A., Meckler, A. N., Hain, M. P., and Haug, G. H.: Changes in North Atlantic nitrogen fixation controlled by ocean circulation, Nature, 501, 200, https://doi.org/10.1038/nature12397, 2013.
Takagi, H., Kimoto, K., Fujiki, T., Kurasawa, A., Moriya, K., and Hirano, H.: Ontogenetic dynamics of photosymbiosis in cultured planktic foraminifers revealed by fast repetition rate fluorometry, Marine Micropaleontol., 122, 44–52, https://doi.org/10.1016/j.marmicro.2015.10.003, 2016.
Takagi, H., Kimoto, K., Fujiki, T., Saito, H., Schmidt, C., Kucera, M., and Moriya, K.: Characterizing photosymbiosis in modern planktonic foraminifera, Biogeosciences, 16, 3377–3396, https://doi.org/10.5194/bg-16-3377-2019, 2019.
Takagi, H., Kimoto, K., and Fujiki, T.: Photosynthetic carbon assimilation and electron transport rates in two symbiont-bearing planktonic foraminifera, Front. Marine Sci., 9, 803354, https://doi.org/10.3389/fmars.2022.803354, 2022.
Uhle, M. E., Macko, S. A., Spero, H. J., Lea, D. W., Ruddiman, W. F., and Engel, M. H.: The fate of nitrogen in the Orbulina universa foraminifera-symbiont system determined by nitrogen isotope analyses of shell-bound organic matter, Limnol. Oceanogr., 44, 1968–1977, https://doi.org/10.4319/lo.1999.44.8.1968, 1999.
Wang, X. T., Prokopenko, M. G., Sigman, D. M., Adkins, J. F., Robinson, L. F., Ren, H., Oleynik, S., Williams, B., and Haug, G. H.: Isotopic composition of carbonate-bound organic nitrogen in deep-sea scleractinian corals: A new window into past biogeochemical change, Earth Planet. Sc. Lett., 400, 243–250, https://doi.org/10.1016/j.epsl.2014.05.048, 2014.
Wang, X., Sigman, D. M., Cohen, A., Sinclair, D., Sherrell, R., Weigand, M., Erler, D. V., and Ren, H.: Isotopic composition of skeleton-bound organic nitrogen in reef-building symbiotic corals: A new method and proxy evaluation at Bermuda, Geochim. Cosmochim. Ac., 148, 179–190, https://doi.org/10.1016/j.gca.2014.09.017, 2015.
Wang, X. T., Wang, Y., Auderset, A., Sigman, D. M., Ren, H., Martínez-García, A., Haug, G. H., Su, Z., Zhang, Y. G., and Rasmussen, B.: Oceanic nutrient rise and the late Miocene inception of Pacific oxygen-deficient zones, P. Natl. Acad. Sci. USA, 119, e2204986119, https://doi.org/10.1073/pnas.2204986119, 2022.
Wefer, G., Berger, W. H., Siedler, G., Webb, D. J., and Reid, J.: On the circulation of the South Atlantic Ocean, The South Atlantic: present and past circulation, 13–44, https://doi.org/10.1007/978-3-642-80353-6_2, 1996.
Weigand, M. A., Foriel, J., Barnett, B., Oleynik, S., and Sigman, D. M.: Updates to instrumentation and protocols for isotopic analysis of nitrate by the denitrifier method, Rapid Commun. Mass Sp., 30, 1365–1383, https://doi.org/10.1002/rcm.7570, 2016.
Yoshikawa, C., Makabe, A., Shiozaki, T., Toyoda, S., Yoshida, O., Furuya, K., and Yoshida, N.: Nitrogen isotope ratios of nitrate and N* anomalies in the subtropical South Pacific, Geochem. Geophys. Geosyst., 16, 1439–1448, https://doi.org/10.1002/2014GC005678, 2015.
Yoshikawa, C., Makabe, A., Matsui, Y., Nunoura, T., and Ohkouchi, N.: Nitrate isotope distribution in the subarctic and subtropical North Pacific, Geochem. Geophys. Geosyst., 19, 2212–2224, https://doi.org/10.1029/2018GC007528, 2018.
Short summary
This study uses foraminifera-bound nitrogen isotopes (FB-δ15N) to investigate photosymbiosis in planktic foraminifera. The analysis of South Atlantic shells, compared to a global dataset, shows that FB-δ15N distinguishes species with certain algal symbionts (dinoflagellates), likely due to internal ammonium recycling. However, the studied site stands out with its larger-than-expected FB-δ15N offsets, highlighting influences on FB-δ15N signatures in regions with strong environmental gradients.
This study uses foraminifera-bound nitrogen isotopes (FB-δ15N) to investigate photosymbiosis in...
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