Articles | Volume 15, issue 4
https://doi.org/10.5194/bg-15-1079-2018
© Author(s) 2018. 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-15-1079-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Technical note
| 
22 Feb 2018
Technical note |
| 22 Feb 2018
| 22 Feb 2018
Technical note: An empirical method for absolute calibration of coccolith thickness
Saúl González-Lemos
CORRESPONDING AUTHOR
Department of Geology, University of Oviedo, Oviedo, 33005, Spain
José Guitián
Department of Earth Sciences, ETH Zurich, Zurich, 8092, Switzerland
Miguel-Ángel Fuertes
Department of Geology, University of Salamanca, Salamanca, 37008,
Spain
José-Abel Flores
Department of Geology, University of Salamanca, Salamanca, 37008,
Spain
Heather M. Stoll
CORRESPONDING AUTHOR
Department of Geology, University of Oviedo, Oviedo, 33005, Spain
Department of Earth Sciences, ETH Zurich, Zurich, 8092, Switzerland
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The Mediterranean Sea is regarded as a climate change hotspot. Documenting the population of planktonic foraminifera is crucial. In the Sicily Channel, fluxes are higher during winter and positively linked with chlorophyll a concentration and cool temperatures. A comparison with other Mediterranean sites shows the transitional aspect of the studied zone. Finally, modern populations significantly differ from those in the sediment, highlighting a possible effect of environmental change.
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Clim. Past, 17, 1903–1918, https://doi.org/10.5194/cp-17-1903-2021, https://doi.org/10.5194/cp-17-1903-2021, 2021
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Soil respiration is a critical but poorly constrained component of the global carbon cycle. We analyse the effect of changing soil respiration rates on the stable carbon isotope ratio of speleothems from northern Spain covering the last deglaciation. Using geochemical analysis and forward modelling we quantify the processes affecting speleothem stable carbon isotope ratios and extract a signature of increasing soil respiration synchronous with deglacial warming.
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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
Catarina Cavaleiro, Antje H. L. Voelker, Heather Stoll, Karl-Heinz Baumann, and Michal Kucera
Clim. Past, 16, 2017–2037, https://doi.org/10.5194/cp-16-2017-2020, https://doi.org/10.5194/cp-16-2017-2020, 2020
Andrés S. Rigual Hernández, Thomas W. Trull, Scott D. Nodder, José A. Flores, Helen Bostock, Fátima Abrantes, Ruth S. Eriksen, Francisco J. Sierro, Diana M. Davies, Anne-Marie Ballegeer, Miguel A. Fuertes, and Lisa C. Northcote
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Coccolithophores account for a major fraction of the carbonate produced in the world's oceans. However, their contribution in the subantarctic Southern Ocean remains undocumented. We quantitatively partition calcium carbonate fluxes amongst coccolithophore species in the Australian–New Zealand sector of the Southern Ocean. We provide new insights into the importance of species other than Emiliania huxleyi in the carbon cycle and assess their possible response to projected environmental change.
Mariem Saavedra-Pellitero, Karl-Heinz Baumann, Miguel Ángel Fuertes, Hartmut Schulz, Yann Marcon, Nele Manon Vollmar, José-Abel Flores, and Frank Lamy
Biogeosciences, 16, 3679–3702, https://doi.org/10.5194/bg-16-3679-2019, https://doi.org/10.5194/bg-16-3679-2019, 2019
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Open ocean phytoplankton include coccolithophore algae, a key element in carbon cycle regulation with important feedbacks to the climate system. We document latitudinal variability in both coccolithophore assemblage and the mass variation in one particular species, Emiliania huxleyi, for a transect across the Drake Passage (in the Southern Ocean). Coccolithophore abundance, diversity and maximum depth habitat decrease southwards, coinciding with changes in the predominant E. huxleyi morphotypes.
Gloria M. Martin-Garcia, Francisco J. Sierro, José A. Flores, and Fátima Abrantes
Clim. Past, 14, 1639–1651, https://doi.org/10.5194/cp-14-1639-2018, https://doi.org/10.5194/cp-14-1639-2018, 2018
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This work documents major oceanographic changes that occurred in the N. Atlantic from 812 to 530 ka and were related to the mid-Pleistocene transition. Since ~ 650 ka, glacials were more prolonged and intense than before. Larger ice sheets may have worked as a positive feedback mechanism to prolong the duration of glacials. We explore the connection between the change in the N. Atlantic oceanography and the enhanced ice-sheet growth, which contributed to the change of cyclicity in climate.
Hongrui Zhang, Heather Stoll, Clara Bolton, Xiaobo Jin, and Chuanlian Liu
Biogeosciences, 15, 4759–4775, https://doi.org/10.5194/bg-15-4759-2018, https://doi.org/10.5194/bg-15-4759-2018, 2018
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The sinking speeds of coccoliths are relevant for laboratory methods to separate coccoliths for geochemical analysis. However, in the absence of estimates of coccolith settling velocity, previous implementations have depended mainly on time-consuming method development by trial and error. In this study, the sinking velocities of cocooliths were carefully measured for the first time. We also provide an estimation of coccolith sinking velocity by shape, which will make coccolith separation easier.
Ariadna Salabarnada, Carlota Escutia, Ursula Röhl, C. Hans Nelson, Robert McKay, Francisco J. Jiménez-Espejo, Peter K. Bijl, Julian D. Hartman, Stephanie L. Strother, Ulrich Salzmann, Dimitris Evangelinos, Adrián López-Quirós, José Abel Flores, Francesca Sangiorgi, Minoru Ikehara, and Henk Brinkhuis
Clim. Past, 14, 991–1014, https://doi.org/10.5194/cp-14-991-2018, https://doi.org/10.5194/cp-14-991-2018, 2018
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Here we reconstruct ice sheet and paleoceanographic configurations in the East Antarctic Wilkes Land margin based on a multi-proxy study conducted in late Oligocene (26–25 Ma) sediments from IODP Site U1356. The new obliquity-forced glacial–interglacial sedimentary model shows that, under the high CO2 values of the late Oligocene, ice sheets had mostly retreated to their terrestrial margins and the ocean was very dynamic with shifting positions of the polar fronts and associated water masses.
Andrés S. Rigual Hernández, José A. Flores, Francisco J. Sierro, Miguel A. Fuertes, Lluïsa Cros, and Thomas W. Trull
Biogeosciences, 15, 1843–1862, https://doi.org/10.5194/bg-15-1843-2018, https://doi.org/10.5194/bg-15-1843-2018, 2018
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Long-term and annual field observations on key organisms are a critical basis for predicting changes in Southern Ocean ecosystems. Coccolithophores are the most abundant calcium-carbonate-producing phytoplankton and play an important role in Southern Ocean biogeochemical cycles. In this study we document the composition, degree of calcification and annual cycle of coccolithophore communities in one of the largest unexplored regions of the world oceans: the Antarctic zone.
Blanca Ausín, Diana Zúñiga, Jose A. Flores, Catarina Cavaleiro, María Froján, Nicolás Villacieros-Robineau, Fernando Alonso-Pérez, Belén Arbones, Celia Santos, Francisco de la Granda, Carmen G. Castro, Fátima Abrantes, Timothy I. Eglinton, and Emilia Salgueiro
Biogeosciences, 15, 245–262, https://doi.org/10.5194/bg-15-245-2018, https://doi.org/10.5194/bg-15-245-2018, 2018
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A systematic investigation of the coccolithophore ecology was performed for the first time in the NW Iberian Margin to broaden our knowledge on the use of fossil coccoliths in marine sediment records to infer environmental conditions in the past. Coccolithophores proved to be significant primary producers and their abundance and distribution was favoured by warmer and nutrient–depleted waters during the upwelling regime, seasonally controlled offshore and influenced by coastal processes onshore.
B. Ausín, I. Hernández-Almeida, J.-A. Flores, F.-J. Sierro, M. Grosjean, G. Francés, and B. Alonso
Clim. Past, 11, 1635–1651, https://doi.org/10.5194/cp-11-1635-2015, https://doi.org/10.5194/cp-11-1635-2015, 2015
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Coccolithophore distribution in 88 surface sediment samples in the Atlantic Ocean and western Mediterranean was mainly influenced by salinity at 10m depth. A quantitative coccolithophore-based transfer function was developed and applied to a fossil sediment core to estimate sea surface salinity (SSS). The quality of this function and the reliability of the SSS reconstruction were assessed by statistical analyses and discussed. Several centennial SSS changes are identified for the last 15.5 ka.
O. Rama-Corredor, B. Martrat, J. O. Grimalt, G. E. López-Otalvaro, J. A. Flores, and F. Sierro
Clim. Past, 11, 1297–1311, https://doi.org/10.5194/cp-11-1297-2015, https://doi.org/10.5194/cp-11-1297-2015, 2015
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The alkenone sea surface temperatures in the Guiana Basin show a rapid transmission of the climate variability from arctic to tropical latitudes during the last two interglacials (MIS1 and MIS5e) and warm long interstadials (MIS5d-a). In contrast, the abrupt variability of the glacial interval does follow the North Atlantic climate but is also shaped by precessional changes. This arctic to tropical decoupling occurs when the Atlantic meridional overturning circulation is substantially reduced.
I. Hernández-Almeida, F.-J. Sierro, I. Cacho, and J.-A. Flores
Clim. Past, 11, 687–696, https://doi.org/10.5194/cp-11-687-2015, https://doi.org/10.5194/cp-11-687-2015, 2015
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This manuscript presents new Mg/Ca and previously published δ18O measurements of Neogloboquadrina pachyderma sinistral for MIS 31-19, from a sediment core from the subpolar North Atlantic. The mechanism proposed here involves northward subsurface transport of warm and salty subtropical waters during periods of weaker AMOC, leading to ice-sheet instability and IRD discharge. This is the first time that these rapid climate oscillations are described for the early Pleistocene.
M. N. Müller, M. Lebrato, U. Riebesell, J. Barcelos e Ramos, K. G. Schulz, S. Blanco-Ameijeiras, S. Sett, A. Eisenhauer, and H. M. Stoll
Biogeosciences, 11, 1065–1075, https://doi.org/10.5194/bg-11-1065-2014, https://doi.org/10.5194/bg-11-1065-2014, 2014
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Changes in calcification of coccoliths under stable atmospheric CO2
Southern Hemisphere imprint for Indo-Asian summer monsoons during the last glacial period as revealed by Arabian Sea productivity records
The calcareous nannofossil Prinsiosphaera achieved rock-forming abundances in the latest Triassic of western Tethys: consequences for the δ13C of bulk carbonate
The Little Ice Age: evidence from a sediment record in Gullmar Fjord, Swedish west coast
Nitrogen isotopes in bulk marine sediment: linking seafloor observations with subseafloor records
Quantitative reconstruction of sea-surface conditions over the last 150 yr in the Beaufort Sea based on dinoflagellate cyst assemblages: the role of large-scale atmospheric circulation patterns
Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar
Pteropods from the Caribbean Sea: variations in calcification as an indicator of past ocean carbonate saturation
Sedimentary organic matter and carbonate variations in the Chukchi Borderland in association with ice sheet and ocean-atmosphere dynamics over the last 155 kyr
Konstantina Agiadi, Iuliana Vasiliev, Geanina Butiseacă, George Kontakiotis, Danae Thivaiou, Evangelia Besiou, Stergios Zarkogiannis, Efterpi Koskeridou, Assimina Antonarakou, and Andreas Mulch
Biogeosciences, 21, 3869–3881, https://doi.org/10.5194/bg-21-3869-2024, https://doi.org/10.5194/bg-21-3869-2024, 2024
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Seven million years ago, the marine gateway connecting the Mediterranean Sea with the Atlantic Ocean started to close, and, as a result, water circulation ceased. To find out how this phenomenon affected the fish living in the Mediterranean Sea, we examined the changes in the isotopic composition of otoliths of two common fish species. Although the species living at the surface fared pretty well, the bottom-water fish starved and eventually became extinct in the Mediterranean.
Rafał Nawrot, Martin Zuschin, Adam Tomašových, Michał Kowalewski, and Daniele Scarponi
Biogeosciences, 21, 2177–2188, https://doi.org/10.5194/bg-21-2177-2024, https://doi.org/10.5194/bg-21-2177-2024, 2024
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The youngest fossil record is a crucial source of data on the history of marine ecosystems and their long-term alteration by humans. However, human activities that reshape ecosystems also alter sedimentary and biological processes that control the formation of the geological archives recording those impacts. Thus, humans have been transforming the marine fossil record in ways that affect our ability to reconstruct past ecological and climate dynamics.
Wanli Xiang, Jan-Peter Duda, Andreas Pack, Mark van Zuilen, and Joachim Reitner
EGUsphere, https://doi.org/10.5194/egusphere-2024-1007, https://doi.org/10.5194/egusphere-2024-1007, 2024
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We investigated the formation of early Archean (~3.5–3.4 Ga) carbonates in the Pilbara Craton, Western Australia, demonstrating the presence of an oceanic crust-, an organo-carbonate-, and a microbial carbonate factory. Notably, (a)biotic organic matter as well as hydrothermal fluids were centrally involved in carbonate precipitation. Since carbonates are widespread in the Archean, they may have constituted major carbon sinks that modulated early Earth’s carbon cycle and, hence, climate system.
Mara Cipriani, Carmine Apollaro, Daniela Basso, Pietro Bazzicalupo, Marco Bertolino, Valentina Alice Bracchi, Fabio Bruno, Gabriele Costa, Rocco Dominici, Alessandro Gallo, Maurizio Muzzupappa, Antonietta Rosso, Rossana Sanfilippo, Francesco Sciuto, Giovanni Vespasiano, and Adriano Guido
Biogeosciences, 21, 49–72, https://doi.org/10.5194/bg-21-49-2024, https://doi.org/10.5194/bg-21-49-2024, 2024
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Who constructs the build-ups of the Mediterranean Sea? What is the role of skeletal and soft-bodied organisms in these bioconstructions? Do bacteria play a role in their formation? In this research, for the first time, the coralligenous of the Mediterranean shelf is studied from a geobiological point of view with an interdisciplinary biological and geological approach, highlighting important biotic relationships that can be used in interpreting the fossil build-up systems.
Mathias Harzhauser, Oleg Mandic, and Werner E. Piller
Biogeosciences, 20, 4775–4794, https://doi.org/10.5194/bg-20-4775-2023, https://doi.org/10.5194/bg-20-4775-2023, 2023
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Bowl-shaped spirorbid microbialite bioherms formed during the late Middle Miocene (Sarmatian) in the central Paratethys Sea under a warm, arid climate. The microbialites and the surrounding sediment document a predominance of microbial activity in the shallow marine environments of the sea at that time. Modern microbialites are not analogues for these unique structures, which reflect a series of growth stages with an initial “start-up stage”, massive “keep-up stage” and termination of growth.
Walid Naciri, Arnoud Boom, Matthew Payne, Nicola Browne, Noreen J. Evans, Philip Holdship, Kai Rankenburg, Ramasamy Nagarajan, Bradley J. McDonald, Jennifer McIlwain, and Jens Zinke
Biogeosciences, 20, 1587–1604, https://doi.org/10.5194/bg-20-1587-2023, https://doi.org/10.5194/bg-20-1587-2023, 2023
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In this study, we tested the ability of massive boulder-like corals to act as archives of land use in Malaysian Borneo to palliate the lack of accurate instrumental data on deforestation before the 1980s. We used mass spectrometry to measure trace element ratios in coral cores to use as a proxy for sediment in river discharge. Results showed an extremely similar increase between our proxy and the river discharge instrumental record, demonstrating the use of these corals as reliable archives.
Thibauld M. Béjard, Andrés S. Rigual-Hernández, José A. Flores, Javier P. Tarruella, Xavier Durrieu de Madron, Isabel Cacho, Neghar Haghipour, Aidan Hunter, and Francisco J. Sierro
Biogeosciences, 20, 1505–1528, https://doi.org/10.5194/bg-20-1505-2023, https://doi.org/10.5194/bg-20-1505-2023, 2023
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The Mediterranean Sea is undergoing a rapid and unprecedented environmental change. Planktic foraminifera calcification is affected on different timescales. On seasonal and interannual scales, calcification trends differ according to the species and are linked mainly to sea surface temperatures and carbonate system parameters, while comparison with pre/post-industrial assemblages shows that all three species have reduced their calcification between 10 % to 35 % according to the species.
Pauline Cornuault, Thomas Westerhold, Heiko Pälike, Torsten Bickert, Karl-Heinz Baumann, and Michal Kucera
Biogeosciences, 20, 597–618, https://doi.org/10.5194/bg-20-597-2023, https://doi.org/10.5194/bg-20-597-2023, 2023
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We generated high-resolution records of carbonate accumulation rate from the Miocene to the Quaternary in the tropical Atlantic Ocean to characterize the variability in pelagic carbonate production during warm climates. It follows orbital cycles, responding to local changes in tropical conditions, as well as to long-term shifts in climate and ocean chemistry. These changes were sufficiently large to play a role in the carbon cycle and global climate evolution.
José Guitián, Miguel Ángel Fuertes, José-Abel Flores, Iván Hernández-Almeida, and Heather Stoll
Biogeosciences, 19, 5007–5019, https://doi.org/10.5194/bg-19-5007-2022, https://doi.org/10.5194/bg-19-5007-2022, 2022
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The effect of environmental conditions on the degree of calcification of marine phytoplankton remains unclear. This study implements a new microscopic approach to quantify the calcification of ancient coccolithophores, using North Atlantic sediments. Results show significant differences in the thickness and shape factor of coccoliths for samples with minimum dissolution, providing the first evaluation of phytoplankton physiology adaptation to million-year-scale variable environmental conditions.
Jeremy N. Bentley, Gregory T. Ventura, Clifford C. Walters, Stefan M. Sievert, and Jeffrey S. Seewald
Biogeosciences, 19, 4459–4477, https://doi.org/10.5194/bg-19-4459-2022, https://doi.org/10.5194/bg-19-4459-2022, 2022
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We demonstrate the TEX86 (TetraEther indeX of 86 carbon atoms) paleoclimate proxy can become heavily impacted by the ocean floor archaeal community. The impact results from source inputs, their diagenetic and catagenetic alteration, and further overprint by the additions of lipids from the ocean floor sedimentary archaeal community. We then present a method to correct the overprints by using IPLs (intact polar lipids) extracted from both water column and subsurface archaeal communities.
Bryan C. Lougheed and Brett Metcalfe
Biogeosciences, 19, 1195–1209, https://doi.org/10.5194/bg-19-1195-2022, https://doi.org/10.5194/bg-19-1195-2022, 2022
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Measurements on sea-dwelling shelled organisms called foraminifera retrieved from deep-sea sediment cores have been used to reconstruct sea surface temperature (SST) variation. To evaluate the method, we use a computer model to simulate millions of single foraminifera and how they become mixed in the sediment after being deposited on the seafloor. We compare the SST inferred from the single foraminifera in the sediment core to the true SST in the water, thus quantifying method uncertainties.
Thore Friesenhagen
Biogeosciences, 19, 777–805, https://doi.org/10.5194/bg-19-777-2022, https://doi.org/10.5194/bg-19-777-2022, 2022
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Size measurements of the planktonic foraminifer Globorotalia menardii and related forms are used to investigate the shell-size evolution for the last 8 million years in the eastern tropical Atlantic Ocean. Long-term changes in the shell size coincide with major climatic, palaeogeographic and palaeoceanographic changes and suggest the occurrence of a new G. menardii type in the Atlantic Ocean ca. 2 million years ago.
Nele Manon Vollmar, Karl-Heinz Baumann, Mariem Saavedra-Pellitero, and Iván Hernández-Almeida
Biogeosciences, 19, 585–612, https://doi.org/10.5194/bg-19-585-2022, https://doi.org/10.5194/bg-19-585-2022, 2022
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We studied recent (sub-)fossil remains of a type of algae (coccolithophores) off southernmost Chile and across the Drake Passage, adding to the scarce knowledge that exists in the Southern Ocean, a rapidly changing environment. We found that those can be used to reconstruct the surface ocean conditions in the north but not in the south. We also found variations in shape in the dominant species Emiliania huxleyi depending on the location, indicating subtle adaptations to environmental conditions.
Catherine V. Davis, Karen Wishner, Willem Renema, and Pincelli M. Hull
Biogeosciences, 18, 977–992, https://doi.org/10.5194/bg-18-977-2021, https://doi.org/10.5194/bg-18-977-2021, 2021
Práxedes Muñoz, Lorena Rebolledo, Laurent Dezileau, Antonio Maldonado, Christoph Mayr, Paola Cárdenas, Carina B. Lange, Katherine Lalangui, Gloria Sanchez, Marco Salamanca, Karen Araya, Ignacio Jara, Gabriel Easton, and Marcel Ramos
Biogeosciences, 17, 5763–5785, https://doi.org/10.5194/bg-17-5763-2020, https://doi.org/10.5194/bg-17-5763-2020, 2020
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We analyze marine sedimentary records to study temporal changes in oxygen and productivity in marine waters of central Chile. We observed increasing oxygenation and decreasing productivity from 6000 kyr ago to the modern era that seem to respond to El Niño–Southern Oscillation activity. In the past centuries, deoxygenation and higher productivity are re-established, mainly in the northern zones of Chile and Peru. Meanwhile, in north-central Chile the deoxygenation trend is maintained.
Luka Šupraha and Jorijntje Henderiks
Biogeosciences, 17, 2955–2969, https://doi.org/10.5194/bg-17-2955-2020, https://doi.org/10.5194/bg-17-2955-2020, 2020
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The cell size, degree of calcification and growth rates of coccolithophores impact their role in the carbon cycle and may also influence their adaptation to environmental change. Combining insights from culture experiments and the fossil record, we show that the selection for smaller cells over the past 15 Myr has been a common adaptive trait among different lineages. However, heavily calcified species maintained a more stable biogeochemical output than the ancestral lineage of E. huxleyi.
Niels J. de Winter, Clemens V. Ullmann, Anne M. Sørensen, Nicolas Thibault, Steven Goderis, Stijn J. M. Van Malderen, Christophe Snoeck, Stijn Goolaerts, Frank Vanhaecke, and Philippe Claeys
Biogeosciences, 17, 2897–2922, https://doi.org/10.5194/bg-17-2897-2020, https://doi.org/10.5194/bg-17-2897-2020, 2020
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In this study, we present a detailed investigation of the chemical composition of 12 specimens of very well preserved, 78-million-year-old oyster shells from southern Sweden. The chemical data show how the oysters grew, the environment in which they lived and how old they became and also provide valuable information about which chemical measurements we can use to learn more about ancient climate and environment from such shells. In turn, this can help improve climate reconstructions and models.
Hannah M. Palmer, Tessa M. Hill, Peter D. Roopnarine, Sarah E. Myhre, Katherine R. Reyes, and Jonas T. Donnenfield
Biogeosciences, 17, 2923–2937, https://doi.org/10.5194/bg-17-2923-2020, https://doi.org/10.5194/bg-17-2923-2020, 2020
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Modern climate change is causing expansions of low-oxygen zones, with detrimental impacts to marine life. To better predict future ocean oxygen change, we study past expansions and contractions of low-oxygen zones using microfossils of seafloor organisms. We find that, along the San Diego margin, the low-oxygen zone expanded into more shallow water in the last 400 years, but the conditions within and below the low-oxygen zone did not change significantly in the last 1500 years.
Yuanyuan Hong, Moriaki Yasuhara, Hokuto Iwatani, and Briony Mamo
Biogeosciences, 16, 585–604, https://doi.org/10.5194/bg-16-585-2019, https://doi.org/10.5194/bg-16-585-2019, 2019
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This study analyzed microfaunal assemblages in surface sediments from 52 sites in Hong Kong marine waters. We selected 18 species for linear regression modeling to statistically reveal the relationship between species distribution and environmental factors. These results show environmental preferences of commonly distributed species on Asian coasts, providing a robust baseline for past environmental reconstruction of the broad Asian region using microfossils in sediment cores.
Jorge Domingo Carrillo-Briceño, Zoneibe Luz, Austin Hendy, László Kocsis, Orangel Aguilera, and Torsten Vennemann
Biogeosciences, 16, 33–56, https://doi.org/10.5194/bg-16-33-2019, https://doi.org/10.5194/bg-16-33-2019, 2019
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By combining taxonomy and geochemistry, we corroborated the described paleoenvironments from a Neogene fossiliferous deposit of South America. Shark teeth specimens were used for taxonomic identification and as proxies for geochemical analyses. With a multidisciplinary approach we refined the understanding about the paleoenvironmental setting and the paleoecological characteristics of the studied groups, in our case, for the bull shark and its incursions into brackish waters.
Anna Binczewska, Bjørg Risebrobakken, Irina Polovodova Asteman, Matthias Moros, Amandine Tisserand, Eystein Jansen, and Andrzej Witkowski
Biogeosciences, 15, 5909–5928, https://doi.org/10.5194/bg-15-5909-2018, https://doi.org/10.5194/bg-15-5909-2018, 2018
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Primary productivity is an important factor in the functioning and structuring of the coastal ecosystem. Thus, two sediment cores from the Skagerrak (North Sea) were investigated in order to obtain a comprehensive picture of primary productivity changes during the last millennium and identify associated forcing factors (e.g. anthropogenic, climate). The cores were dated and analysed for palaeoproductivity proxies and palaeothermometers.
Sami A. Jokinen, Joonas J. Virtasalo, Tom Jilbert, Jérôme Kaiser, Olaf Dellwig, Helge W. Arz, Jari Hänninen, Laura Arppe, Miia Collander, and Timo Saarinen
Biogeosciences, 15, 3975–4001, https://doi.org/10.5194/bg-15-3975-2018, https://doi.org/10.5194/bg-15-3975-2018, 2018
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Oxygen deficiency is a major environmental problem deteriorating seafloor habitats especially in the coastal ocean with large human impact. Here we apply a wide set of chemical and physical analyses to a 1500-year long sediment record and show that, although long-term climate variability has modulated seafloor oxygenation in the coastal northern Baltic Sea, the oxygen loss over the 20th century is unprecedentedly severe, emphasizing the need to reduce anthropogenic nutrient input in the future.
Ulrich Kotthoff, Jeroen Groeneveld, Jeanine L. Ash, Anne-Sophie Fanget, Nadine Quintana Krupinski, Odile Peyron, Anna Stepanova, Jonathan Warnock, Niels A. G. M. Van Helmond, Benjamin H. Passey, Ole Rønø Clausen, Ole Bennike, Elinor Andrén, Wojciech Granoszewski, Thomas Andrén, Helena L. Filipsson, Marit-Solveig Seidenkrantz, Caroline P. Slomp, and Thorsten Bauersachs
Biogeosciences, 14, 5607–5632, https://doi.org/10.5194/bg-14-5607-2017, https://doi.org/10.5194/bg-14-5607-2017, 2017
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We present reconstructions of paleotemperature, paleosalinity, and paleoecology from the Little Belt (Site M0059) over the past ~ 8000 years and evaluate the applicability of numerous proxies. Conditions were lacustrine until ~ 7400 cal yr BP. A transition to brackish–marine conditions then occurred within ~ 200 years. Salinity proxies rarely allowed quantitative estimates but revealed congruent results, while quantitative temperature reconstructions differed depending on the proxies used.
Shuichang Zhang, Xiaomei Wang, Huajian Wang, Emma U. Hammarlund, Jin Su, Yu Wang, and Donald E. Canfield
Biogeosciences, 14, 2133–2149, https://doi.org/10.5194/bg-14-2133-2017, https://doi.org/10.5194/bg-14-2133-2017, 2017
Liza M. Roger, Annette D. George, Jeremy Shaw, Robert D. Hart, Malcolm Roberts, Thomas Becker, Bradley J. McDonald, and Noreen J. Evans
Biogeosciences, 14, 1721–1737, https://doi.org/10.5194/bg-14-1721-2017, https://doi.org/10.5194/bg-14-1721-2017, 2017
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The shell compositions of bivalve species from south Western Australia are described here to better understand the factors involved in their formation. The shell composition can be used to reconstruct past environmental conditions, but certain species manifest an offset compared to the environmental parameters measured. As shown here, shells that experience the same conditions can present different compositions in relation to structure, organic composition and environmental conditions.
Johan Vellekoop, Lineke Woelders, Sanem Açikalin, Jan Smit, Bas van de Schootbrugge, Ismail Ö. Yilmaz, Henk Brinkhuis, and Robert P. Speijer
Biogeosciences, 14, 885–900, https://doi.org/10.5194/bg-14-885-2017, https://doi.org/10.5194/bg-14-885-2017, 2017
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The Cretaceous–Paleogene boundary, ~ 66 Ma, is characterized by a mass extinction. We studied groups of both surface-dwelling and bottom-dwelling organisms to unravel the oceanographic consequences of these extinctions. Our integrated records indicate that a reduction of the transport of organic matter to the sea floor resulted in enhanced recycling of nutrients in the upper water column and decreased food supply at the sea floor in the first tens of thousands of years after the extinctions.
Johan Renaudie
Biogeosciences, 13, 6003–6014, https://doi.org/10.5194/bg-13-6003-2016, https://doi.org/10.5194/bg-13-6003-2016, 2016
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Marine planktonic diatoms are today both the main silica and carbon exporter to the deep sea. However, 50 million years ago, radiolarians were the main silica exporter and diatoms were a rare, geographically restricted group. Quantification of their rise to dominance suggest that diatom abundance is primarily controlled by the continental weathering and has a negative feedback, observable on a geological timescale, on the carbon cycle.
Jelena Vidović, Rafał Nawrot, Ivo Gallmetzer, Alexandra Haselmair, Adam Tomašových, Michael Stachowitsch, Vlasta Ćosović, and Martin Zuschin
Biogeosciences, 13, 5965–5981, https://doi.org/10.5194/bg-13-5965-2016, https://doi.org/10.5194/bg-13-5965-2016, 2016
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We studied the ecological history of the Gulf of Trieste. Before the 20th century, the only activity here was ore mining, releasing high amounts of mercury into its northern part, Panzano Bay. Mercury did not cause changes to microorganisms, as it is not bioavailable. In the 20th century, agriculture caused nutrient enrichment in the bay and increased diversity of microorganisms. Industrial activities increased the concentrations of pollutants, causing only minor changes to microorganisms.
Aurélie Penaud, Frédérique Eynaud, Antje Helga Luise Voelker, and Jean-Louis Turon
Biogeosciences, 13, 5357–5377, https://doi.org/10.5194/bg-13-5357-2016, https://doi.org/10.5194/bg-13-5357-2016, 2016
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This paper presents new analyses conducted at high resolution in the Gulf of Cadiz over the last 50 ky. Palaeohydrological changes in these subtropical latitudes are discussed through dinoflagellate cyst assemblages but also dinocyst transfer function results, implying sea surface temperature and salinity as well as annual productivity reconstructions. This study is thus important for our understanding of past and future productivity regimes, also implying consequences on the biological pump.
William Hardy, Aurélie Penaud, Fabienne Marret, Germain Bayon, Tania Marsset, and Laurence Droz
Biogeosciences, 13, 4823–4841, https://doi.org/10.5194/bg-13-4823-2016, https://doi.org/10.5194/bg-13-4823-2016, 2016
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Our approach is based on a multi-proxy study from a core collected off the Congo River and discusses surface oceanic conditions (upwelling cells, river-induced upwelling), land–sea interactions and terrestrial erosion and in particular enables us to spatially constrain the migration of atmospheric systems. This paper thus presents new data highlighting, with the highest resolution ever reached in this region, the great correlation between phytoplanktonic organisms and monsoonal mechanisms.
Philippine Campagne, Xavier Crosta, Sabine Schmidt, Marie Noëlle Houssais, Olivier Ther, and Guillaume Massé
Biogeosciences, 13, 4205–4218, https://doi.org/10.5194/bg-13-4205-2016, https://doi.org/10.5194/bg-13-4205-2016, 2016
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Diatoms and biomarkers have been recently used for palaeoclimate reconstructions in the Southern Ocean. Few sediment-based ecological studies have investigated their relationships with environmental conditions. Here, we compare high-resolution sedimentary records with meteorological data to study relationships between our proxies and recent atmospheric and sea surface changes. Our results indicate that coupled wind pattern and sea surface variability act as the proximal forcing at that scale.
Niels A. G. M. van Helmond, Appy Sluijs, Nina M. Papadomanolaki, A. Guy Plint, Darren R. Gröcke, Martin A. Pearce, James S. Eldrett, João Trabucho-Alexandre, Ireneusz Walaszczyk, Bas van de Schootbrugge, and Henk Brinkhuis
Biogeosciences, 13, 2859–2872, https://doi.org/10.5194/bg-13-2859-2016, https://doi.org/10.5194/bg-13-2859-2016, 2016
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Over the past decades large changes have been observed in the biogeographical dispersion of marine life resulting from climate change. To better understand present and future trends it is important to document and fully understand the biogeographical response of marine life during episodes of environmental change in the geological past.
Here we investigate the response of phytoplankton, the base of the marine food web, to a rapid cold spell, interrupting greenhouse conditions during the Cretaceous.
Thomas C. Brachert, Markus Reuter, Stefan Krüger, Julia Kirkerowicz, and James S. Klaus
Biogeosciences, 13, 1469–1489, https://doi.org/10.5194/bg-13-1469-2016, https://doi.org/10.5194/bg-13-1469-2016, 2016
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We present stable isotope proxy data and calcification records from fossil reef corals. The corals investigated derive from the Florida carbonate platform and are of middle Pliocene to early Pleistocene age. From the data we infer an environment subject to intermittent upwelling on annual to decadal timescales. Calcification rates were enhanced during periods of upwelling. This is likely an effect of dampened SSTs during the upwelling.
B. A. A. Hoogakker, D. J. R. Thornalley, and S. Barker
Biogeosciences, 13, 211–221, https://doi.org/10.5194/bg-13-211-2016, https://doi.org/10.5194/bg-13-211-2016, 2016
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Models predict a decrease in future ocean O2, driven by surface water warming and freshening in the polar regions, causing a reduction in ocean circulation. Here we assess this effect in the past, focussing on the response of deep and intermediate waters from the North Atlantic during large-scale ice rafting and millennial-scale cooling events of the last glacial.
Our assessment agrees with the models but also highlights the importance of biological processes driving ocean O2 change.
M. Hermoso, I. Z. X. Chan, H. L. O. McClelland, A. M. C. Heureux, and R. E. M. Rickaby
Biogeosciences, 13, 301–312, https://doi.org/10.5194/bg-13-301-2016, https://doi.org/10.5194/bg-13-301-2016, 2016
B. Metcalfe, W. Feldmeijer, M. de Vringer-Picon, G.-J. A. Brummer, F. J. C. Peeters, and G. M. Ganssen
Biogeosciences, 12, 4781–4807, https://doi.org/10.5194/bg-12-4781-2015, https://doi.org/10.5194/bg-12-4781-2015, 2015
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Iron biogeochemical budgets during the natural ocean fertilisation experiment KEOPS-2 showed that complex circulation and transport pathways were responsible for differences in the mode and strength of iron supply, with vertical supply dominant on the plateau and lateral supply dominant in the plume. The exchange of iron between dissolved, biogenic and lithogenic pools was highly dynamic, resulting in a decoupling of iron supply and carbon export and controlling the efficiency of fertilisation.
J. P. D'Olivo, M. T. McCulloch, S. M. Eggins, and J. Trotter
Biogeosciences, 12, 1223–1236, https://doi.org/10.5194/bg-12-1223-2015, https://doi.org/10.5194/bg-12-1223-2015, 2015
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The boron isotope composition in the skeleton of massive Porites corals from the central Great Barrier Reef is used to reconstruct the seawater pH over the 1940-2009 period. The long-term decline in the coral-reconstructed seawater pH is in close agreement with estimates based on the CO2 uptake by surface waters due to rising atmospheric levels. We also observed a significant relationship between terrestrial runoff data and the inshore coral boron isotopes records.
J. Schönfeld, W. Kuhnt, Z. Erdem, S. Flögel, N. Glock, M. Aquit, M. Frank, and A. Holbourn
Biogeosciences, 12, 1169–1189, https://doi.org/10.5194/bg-12-1169-2015, https://doi.org/10.5194/bg-12-1169-2015, 2015
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Today’s oceans show distinct mid-depth oxygen minima while whole oceanic basins became transiently anoxic in the Mesozoic. To constrain past bottom-water oxygenation, we compared sediments from the Peruvian OMZ with the Cenomanian OAE 2 from Morocco. Corg accumulation rates in laminated OAE 2 sections match Holocene rates off Peru. Laminated deposits are found at oxygen levels of < 7µmol kg-1; crab burrows appear at 10µmol kg-1 today, both defining threshold values for palaeoreconstructions.
S. C. Löhr and M. J. Kennedy
Biogeosciences, 11, 4971–4983, https://doi.org/10.5194/bg-11-4971-2014, https://doi.org/10.5194/bg-11-4971-2014, 2014
R. Hoffmann, J. A. Schultz, R. Schellhorn, E. Rybacki, H. Keupp, S. R. Gerden, R. Lemanis, and S. Zachow
Biogeosciences, 11, 2721–2739, https://doi.org/10.5194/bg-11-2721-2014, https://doi.org/10.5194/bg-11-2721-2014, 2014
T. J. Algeo, P. A. Meyers, R. S. Robinson, H. Rowe, and G. Q. Jiang
Biogeosciences, 11, 1273–1295, https://doi.org/10.5194/bg-11-1273-2014, https://doi.org/10.5194/bg-11-1273-2014, 2014
C. Berger, K. J. S. Meier, H. Kinkel, and K.-H. Baumann
Biogeosciences, 11, 929–944, https://doi.org/10.5194/bg-11-929-2014, https://doi.org/10.5194/bg-11-929-2014, 2014
T. Caley, S. Zaragosi, J. Bourget, P. Martinez, B. Malaizé, F. Eynaud, L. Rossignol, T. Garlan, and N. Ellouz-Zimmermann
Biogeosciences, 10, 7347–7359, https://doi.org/10.5194/bg-10-7347-2013, https://doi.org/10.5194/bg-10-7347-2013, 2013
N. Preto, C. Agnini, M. Rigo, M. Sprovieri, and H. Westphal
Biogeosciences, 10, 6053–6068, https://doi.org/10.5194/bg-10-6053-2013, https://doi.org/10.5194/bg-10-6053-2013, 2013
I. Polovodova Asteman, K. Nordberg, and H. L. Filipsson
Biogeosciences, 10, 1275–1290, https://doi.org/10.5194/bg-10-1275-2013, https://doi.org/10.5194/bg-10-1275-2013, 2013
J.-E. Tesdal, E. D. Galbraith, and M. Kienast
Biogeosciences, 10, 101–118, https://doi.org/10.5194/bg-10-101-2013, https://doi.org/10.5194/bg-10-101-2013, 2013
L. Durantou, A. Rochon, D. Ledu, G. Massé, S. Schmidt, and M. Babin
Biogeosciences, 9, 5391–5406, https://doi.org/10.5194/bg-9-5391-2012, https://doi.org/10.5194/bg-9-5391-2012, 2012
C. A. Grove, J. Zinke, T. Scheufen, J. Maina, E. Epping, W. Boer, B. Randriamanantsoa, and G.-J. A. Brummer
Biogeosciences, 9, 3063–3081, https://doi.org/10.5194/bg-9-3063-2012, https://doi.org/10.5194/bg-9-3063-2012, 2012
D. Wall-Palmer, M. B. Hart, C. W. Smart, R. S. J. Sparks, A. Le Friant, G. Boudon, C. Deplus, and J. C. Komorowski
Biogeosciences, 9, 309–315, https://doi.org/10.5194/bg-9-309-2012, https://doi.org/10.5194/bg-9-309-2012, 2012
S. F. Rella and M. Uchida
Biogeosciences, 8, 3545–3553, https://doi.org/10.5194/bg-8-3545-2011, https://doi.org/10.5194/bg-8-3545-2011, 2011
Cited articles
Abrantes, F., Meggers, H., Nave, S., Bollman, J., Palma, S., Sprengel, C., Henderiks, J., Spies, A., Salgueiro, E., Moita, T., and Neuer, S.: Fluxes of micro-organisms along a productivity gradient in the Canary Islands region (29° N): implications for paleoreconstructions, Deep-Sea Res. Pt. II, 49, 3599–3629, https://doi.org/10.1016/S0967-0645(02)00100-5, 2002.
Armstrong, R. A., Lee, C., Hedges, J. I., Honjo, S., and Wakeham, S. G.: A new, mechanistic model for organic carbon fluxes in the ocean based on the quantitative association of POC with ballast minerals, Deep-Sea Res. Pt. II, 49, 219–236, https://doi.org/10.1016/S0967-0645(01)00101-1, 2002.
Armstrong, R. A., Peterson, M. L., Lee, C., and Wakeham, S. G.: Settling velocity spectra and the ballast ratio hypothesis, Deep-Sea Res. Pt. II, 56, 1470–1478, https://doi.org/10.1016/j.dsr2.2008.11.032, 2009.
Bárcena, M. A., Flores, J. A., Sierro, F. J., Pérez-Folgado, M., Fabres, J., Calafat, A., and Canals, M.: Planktonic response to main oceanographic changes in the Alboran Sea (Western Mediterranean) as documented in sediment traps and surface sediments, Marine Micropaleontol., 53, 423–445, https://doi.org/10.1016/j.marmicro.2004.09.009, 2004.
Bass, M.: Handbook of optics, 3rd Edn., McGraw-Hill, 2009.
Beaufort, L.: Weight estimates of coccoliths using the optical properties (birefringence) of calcite, Micropaleontology, 51, 289–297, https://doi.org/10.2113/gsmicropal.51.4.289, 2005.
Beaufort, L. and Dollfus, D.: Automatic recognition of coccoliths by dynamical neural networks, Mar. Micropaleontol., 51, 57–73, 2004.
Beaufort, L., Barbarin, N., and Gally, Y.: Optical measurements to determine the thickness of calcite crystals and the mass of thin carbonate particles such as coccoliths, Nat. Protoc., 9, 633–642, https://doi.org/10.1038/nprot.2014.028, 2014.
Berger, W. H., Smetacek, V., and Wefer, G.: Ocean productivity and paleoproductivity-an overview, Productivity of the Oceans present and past: Report of the Dahlem Workshop on Productivity of the Ocean, Berlín, 1–34, 1989.
Bollmann, J.: Technical Note: Weight approximation of coccoliths using a circular polarizer and interference colour derived retardation estimates – (The CPR Method), Biogeosciences, 11, 1899–1910, https://doi.org/10.5194/bg-11-1899-2014, 2014.
Bolton, C. T., Hernández-Sánchez, M. T., Fuertes, M. Á., González-Lemos, S., Abrevaya, L., Mendez-Vicente, A., Flores, J.-A., Probert, I., Giosan, L., Johnson, J., and Stoll, H. M.: Decrease in coccolithophore calcification and CO2 since the middle Miocene, Nat. Commun., 7, 10284, https://doi.org/10.1038/ncomms10284, 2016.
Craig, D. B.: The Benford plate, Am. Mineral., 46, 757–758, 1961.
Delly, J. G.: The Michel-Lévy interference color chart – microscopy's magical color key, available at: https://www.mccrone.com/mm/the-michel-levy-interference-color-chart-microscopys-magical-color-key/ (last access: 14 February 2018), 2003.
Engel, A., Abramson, L., Szlosek, J., Liu, Z., Stewart, G., Hirschberg, D., and Lee, C.: Investigating the effect of ballasting by CaCO3 in Emiliania huxleyi, II: Decomposition of particulate organic matter, Deep-Sea Res. Pt. II, 56, 1408–1419, https://doi.org/10.1016/j.dsr2.2008.11.028, 2009.
Flores, J. A. and Sierro, F. J.: Revised technique for calculation of calcareous nannofossil accumulation rates, Micropaleontology, 43, 321–324, https://doi.org/10.2307/1485832, 1997.
Frohlich, M. W.: Birefringent objects visualized by circular polarization microscopy, Stain Technol., 61, 139–143, 1986.
Fuertes, M. Á., Flores, J. A., and Sierro, F. J.: The use of circularly polarized light for biometry, identification and estimation of mass of coccoliths, Mar. Micropaleontol., 113, 44–55, https://doi.org/10.1016/j.marmicro.2014.08.007, 2014.
Hecht, E.: Optics, 4th. International Edn., Addison-Wesley, San Francisco, Vol. 3, 2002.
Higgins, M. D.: Imaging birefringent minerals without extinction using circularly polarized light, Can. Mineral., 48, 231–235, https://doi.org/10.3749/canmin.48.1.231, 2010.
Iversen, M. H. and Ploug, H.: Ballast minerals and the sinking carbon flux in the ocean: carbon-specific respiration rates and sinking velocity of marine snow aggregates, Biogeosciences, 7, 2613–2624, https://doi.org/10.5194/bg-7-2613-2010, 2010.
Johnsen, L. S., Bollmann, J., Lee, H. W., and Zhou, Y.: Accurate representation of interference colours (Michel-Lévy chart): from rendering to image colour correction, J. Microsc.-Oxford, https://doi.org/10.1111/jmi.12641, online first, 2017.
Lochte, A. A.: Single coccolith weight estimates using two birefringence methods on cultured Gephyrocapsa oceanica, MsC, Uppsala, Sweden, 2014.
Milliman, J. D.: Production and accumulation of calcium carbonate in the ocean: budget of a nonsteady state, Global Biogeochem. Cy., 7, 927–957, https://doi.org/10.1029/93GB02524, 1993.
Norris, R., Wilson, P., Blum, P., and ExpeditionScientists: Proceedings IODP, 342, College Station, TX (Integrated Ocean Drilling Program), https://doi.org/10.2204/iodp, 2014.
O'Dea, S. A., Gibbs, S. J., Bown, P. R., Young, J. R., Poulton, A. J., Newsam, C., and Wilson, P. A.: Coccolithophore calcification response to past ocean acidification and climate change, Nat. Commun., 5, 5363, https://doi.org/10.1038/ncomms6363, 2014.
Ridgwell, A. and Zeebe, R. E.: The role of the global carbonate cycle in the regulation and evolution of the Earth system, Earth Planet. Sc. Lett., 234, 299–315, https://doi.org/10.1016/j.epsl.2005.03.006, 2005.
Siesser, W. G.: Calcareous nannoplankton, in: Fossil Prokaryotes and Protists, edited by: Lipps, J. H., Blackwell Scientific Publications, Boston, 169–201, 1993.
Sørensen, B. E.: A revised Michel-Lévy interference colour chart based on first-principles calculations, Eur. J. Mineral., 25, 5–10, https://doi.org/10.1127/0935-1221/2013/0025-2252, 2013.
van de Locht, R., Slater, T. J., Verch, A., Young, J. R., Haigh, S. J., and Kröger, R.: Ultrastructure and crystallography of nanoscale calcite building blocks in Rhabdosphaera clavigera coccolith spines, Cryst. Growth Des., 14, 1710–1718, https://doi.org/10.1021/cg4018486, 2014.
Young, J. R., Geisen, M., Cros, L., Kleijne, A., Sprengel, C., Probert, I., and Østergaard, J.: A guide to extant coccolithophore taxonomy, Journal of Nannoplankton Research, 1, 1–125, 2003.
Ziveri, P., de Bernardi, B., Baumann, K.-H., Stoll, H. M., and Mortyn, P. G.: Sinking of coccolith carbonate and potential contribution to organic carbon ballasting in the deep ocean, Deep-Sea Res. Pt. II, 54, 659–675, https://doi.org/10.1016/j.dsr2.2007.01.006, 2007.
Short summary
Changes in atmospheric carbon dioxide affect ocean chemistry and the ability of marine organisms to manufacture shells from calcium carbonate. We describe a technique to obtain more reproducible measurements of the thickness of calcium carbonate shells made by microscopic marine algae called coccolithophores, which will allow researchers to compare how the shell thickness responds to variations in ocean chemistry in the past and present.
Changes in atmospheric carbon dioxide affect ocean chemistry and the ability of marine organisms...
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