Articles | Volume 14, issue 24
https://doi.org/10.5194/bg-14-5663-2017
© Author(s) 2017. 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-14-5663-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
15 Dec 2017
Research article |
| 15 Dec 2017
| 15 Dec 2017
Scotland's forgotten carbon: a national assessment of mid-latitude fjord sedimentary carbon stocks
School of Geography & Geosciences, University of St Andrews, St Andrews, KY16 9AL, UK
William E. N. Austin
School of Geography & Geosciences, University of St Andrews, St Andrews, KY16 9AL, UK
Scottish Association for Marine Science, Scottish Marine Institute, Oban, PA37 1QA, UK
Althea L. Davies
School of Geography & Geosciences, University of St Andrews, St Andrews, KY16 9AL, UK
Agnes Baltzer
Institut de Géographie et d'Aménagement Régional de l'Université de Nantes, BP 81 227 44312 Nantes CEDEX 3, France
John A. Howe
Scottish Association for Marine Science, Scottish Marine Institute, Oban, PA37 1QA, UK
John M. Baxter
Scottish Natural Heritage, Silvan House, Edinburgh, EH12 7AT, UK
Related authors
William Hiles, Lucy C. Miller, Craig Smeaton, and William E. N. Austin
Biogeosciences, 21, 929–948, https://doi.org/10.5194/bg-21-929-2024, https://doi.org/10.5194/bg-21-929-2024, 2024
Short summary
Short summary
Saltmarsh soils may help to limit the rate of climate change by storing carbon. To understand their impacts, they must be accurately mapped. We use drone data to estimate the size of three saltmarshes in NE Scotland. We find that drone imagery, combined with tidal data, can reliably inform our understanding of saltmarsh size. When compared with previous work using vegetation communities, we find that our most reliable new estimates of stored carbon are 15–20 % smaller than previously estimated.
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
Short summary
Short summary
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.
Craig Smeaton, Xingqian Cui, Thomas S. Bianchi, Alix G. Cage, John A. Howe, and William E. N. Austin
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-163, https://doi.org/10.5194/bg-2019-163, 2019
Publication in BG not foreseen
Short summary
Short summary
The sediments in fjords are known to be important sites for locking carbon away for long periods of time (thousands of years) but the processes by which climate and human activity influence the development of these coastal carbon stores is poorly understood. A record of long-term sediment burial from a Scottish fjord allows us to investigate the role that humans and climate has played. The results indicate that both climate and humans have an impact on terrestrial ecosystems.
Craig Smeaton, William E. N. Austin, Althea L. Davies, Agnès Baltzer, Richard E. Abell, and John A. Howe
Biogeosciences, 13, 5771–5787, https://doi.org/10.5194/bg-13-5771-2016, https://doi.org/10.5194/bg-13-5771-2016, 2016
Short summary
Short summary
Quantifying the carbon (C) stored within coastal sediments is key to improving our knowledge of the local and global C cycle. Here we present a new methodology to calculate the quantity of C held within coastal sediments. Through the application of this method to a mid-latitude fjord we have shown that a substantial quantity of C is held within these sediments. Additionally, we discovered that these sediments are more effective long-term stores of C than their terrestrial equivalents.
Alex Houston, Mark H. Garnett, Jo Smith, and William E. N. Austin
EGUsphere, https://doi.org/10.5194/egusphere-2024-3281, https://doi.org/10.5194/egusphere-2024-3281, 2024
Short summary
Short summary
The organic carbon stored in saltmarsh soils can be up to 15,000 years old. We found that less energy is required to decompose young carbon than old carbon, i.e., young carbon tends to be more labile. We show that the labile carbon can still be up to 2,000 years old, implying that even old carbon in saltmarsh soils may contribute to greenhouse gas emissions. Protecting saltmarshes from degradation may help conserve these stores of old, labile organic carbon and hence limit CO2 emissions.
William Hiles, Lucy C. Miller, Craig Smeaton, and William E. N. Austin
Biogeosciences, 21, 929–948, https://doi.org/10.5194/bg-21-929-2024, https://doi.org/10.5194/bg-21-929-2024, 2024
Short summary
Short summary
Saltmarsh soils may help to limit the rate of climate change by storing carbon. To understand their impacts, they must be accurately mapped. We use drone data to estimate the size of three saltmarshes in NE Scotland. We find that drone imagery, combined with tidal data, can reliably inform our understanding of saltmarsh size. When compared with previous work using vegetation communities, we find that our most reliable new estimates of stored carbon are 15–20 % smaller than previously estimated.
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
Short summary
Short summary
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.
Craig Smeaton, Xingqian Cui, Thomas S. Bianchi, Alix G. Cage, John A. Howe, and William E. N. Austin
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-163, https://doi.org/10.5194/bg-2019-163, 2019
Publication in BG not foreseen
Short summary
Short summary
The sediments in fjords are known to be important sites for locking carbon away for long periods of time (thousands of years) but the processes by which climate and human activity influence the development of these coastal carbon stores is poorly understood. A record of long-term sediment burial from a Scottish fjord allows us to investigate the role that humans and climate has played. The results indicate that both climate and humans have an impact on terrestrial ecosystems.
Jeroen Groeneveld, Helena L. Filipsson, William E. N. Austin, Kate Darling, David McCarthy, Nadine B. Quintana Krupinski, Clare Bird, and Magali Schweizer
J. Micropalaeontol., 37, 403–429, https://doi.org/10.5194/jm-37-403-2018, https://doi.org/10.5194/jm-37-403-2018, 2018
Short summary
Short summary
Current climate and environmental changes strongly affect shallow marine and coastal areas like the Baltic Sea. The combination of foraminiferal geochemistry and environmental parameters demonstrates that in a highly variable setting like the Baltic Sea, it is possible to separate different environmental impacts on the foraminiferal assemblages and therefore use chemical factors to reconstruct how seawater temperature, salinity, and oxygen varied in the past and may vary in the future.
Craig Smeaton, William E. N. Austin, Althea L. Davies, Agnès Baltzer, Richard E. Abell, and John A. Howe
Biogeosciences, 13, 5771–5787, https://doi.org/10.5194/bg-13-5771-2016, https://doi.org/10.5194/bg-13-5771-2016, 2016
Short summary
Short summary
Quantifying the carbon (C) stored within coastal sediments is key to improving our knowledge of the local and global C cycle. Here we present a new methodology to calculate the quantity of C held within coastal sediments. Through the application of this method to a mid-latitude fjord we have shown that a substantial quantity of C is held within these sediments. Additionally, we discovered that these sediments are more effective long-term stores of C than their terrestrial equivalents.
Related subject area
Biogeochemistry: Sediment
Influence of minor hydrocarbon seepage on sulfur cycling in marine subsurface sediments
Dissolved Mn(III) is a key redox intermediate in sediments of a seasonally euxinic coastal basin
Unexpected scarcity of ANME archaea in hydrocarbon seeps within Monterey Bay
Organic Carbon, Mercury, and Sediment Characteristics along a land – shore transect in Arctic Alaska
Reviews and syntheses: Tufa microbialites on rocky coasts – towards an integrated terminology
Seafloor sediment characterization improves estimates of organic carbon standing stocks: an example from the Eastern Shore Islands, Nova Scotia, Canada
How is particulate organic carbon transported through the river-fed submarine Congo Canyon to the deep sea?
Ancient clays support contemporary biogeochemical activity in the Critical Zone
The fate of fixed nitrogen in Santa Barbara Basin sediments during seasonal anoxia
Distinct oxygenation modes of the Gulf of Oman over the past 43 000 years – a multi-proxy approach
Potential impacts of cable bacteria activity on hard-shelled benthic foraminifera: implications for their interpretation as bioindicators or paleoproxies
Evidence of cryptic methane cycling and non-methanogenic methylamine consumption in the sulfate-reducing zone of sediment in the Santa Barbara Basin, California
Assessing global-scale organic matter reactivity patterns in marine sediments using a lognormal reactive continuum model
Deposit-feeding of Nonionellina labradorica (foraminifera) from an Arctic methane seep site and possible association with a methanotroph
Benthic silicon cycling in the Arctic Barents Sea: a reaction–transport model study
Long-term incubations provide insight into the mechanisms of anaerobic oxidation of methane in methanogenic lake sediments
Ideas and perspectives: Sea-level change, anaerobic methane oxidation, and the glacial–interglacial phosphorus cycle
Estimation of the natural background of phosphate in a lowland river using tidal marsh sediment cores
Geochemical consequences of oxygen diffusion from the oceanic crust into overlying sediments and its significance for biogeochemical cycles based on sediments of the northeast Pacific
Carbon sources of benthic fauna in temperate lakes across multiple trophic states
Deep-water inflow event increases sedimentary phosphorus release on a multi-year scale
Bioturbation has a limited effect on phosphorus burial in salt marsh sediments
Biogeochemical impact of cable bacteria on coastal Black Sea sediment
Organic carbon characteristics in ice-rich permafrost in alas and Yedoma deposits, central Yakutia, Siberia
The control of hydrogen sulfide on benthic iron and cadmium fluxes in the oxygen minimum zone off Peru
Quantity and distribution of methane entrapped in sediments of calcareous, Alpine glacier forefields
Assessing the potential for non-turbulent methane escape from the East Siberian Arctic Shelf
Vertical transport of sediment-associated metals and cyanobacteria by ebullition in a stratified lake
Evidence of changes in sedimentation rate and sediment fabric in a low-oxygen setting: Santa Monica Basin, CA
Authigenic formation of Ca–Mg carbonates in the shallow alkaline Lake Neusiedl, Austria
Vivianite formation in ferruginous sediments from Lake Towuti, Indonesia
Impact of ambient conditions on the Si isotope fractionation in marine pore fluids during early diagenesis
Impact of small-scale disturbances on geochemical conditions, biogeochemical processes and element fluxes in surface sediments of the eastern Clarion–Clipperton Zone, Pacific Ocean
Acetate turnover and methanogenic pathways in Amazonian lake sediments
Benthic alkalinity and dissolved inorganic carbon fluxes in the Rhône River prodelta generated by decoupled aerobic and anaerobic processes
Small-scale heterogeneity of trace metals including rare earth elements and yttrium in deep-sea sediments and porewaters of the Peru Basin, southeastern equatorial Pacific
Organic matter contents and degradation in a highly trawled area during fresh particle inputs (Gulf of Castellammare, southwestern Mediterranean)
Identifying the core bacterial microbiome of hydrocarbon degradation and a shift of dominant methanogenesis pathways in the oil and aqueous phases of petroleum reservoirs of different temperatures from China
Effects of eutrophication on sedimentary organic carbon cycling in five temperate lakes
Evidence for microbial iron reduction in the methanic sediments of the oligotrophic southeastern Mediterranean continental shelf
Fracture-controlled fluid transport supports microbial methane-oxidizing communities at Vestnesa Ridge
Hydrothermal alteration of aragonitic biocarbonates: assessment of micro- and nanostructural dissolution–reprecipitation and constraints of diagenetic overprint from quantitative statistical grain-area analysis
Large variations in iron input to an oligotrophic Baltic Sea estuary: impact on sedimentary phosphorus burial
Vivianite formation in methane-rich deep-sea sediments from the South China Sea
Benthic archaea as potential sources of tetraether membrane lipids in sediments across an oxygen minimum zone
Carbon amendment stimulates benthic nitrogen cycling during the bioremediation of particulate aquaculture waste
Modelling biogeochemical processes in sediments from the north-western Adriatic Sea: response to enhanced particulate organic carbon fluxes
Carbon mineralization in Laptev and East Siberian sea shelf and slope sediment
Reviews and syntheses: to the bottom of carbon processing at the seafloor
Does denitrification occur within porous carbonate sand grains?
Ellen Schnabel, Aurèle Vuillemin, Cédric C. Laczny, Benoit J. Kunath, André R. Soares, Alexander J. Probst, Rolando Di Primio, Jens Kallmeyer, and the PROSPECTOMICS Consortium
Biogeosciences, 22, 767–784, https://doi.org/10.5194/bg-22-767-2025, https://doi.org/10.5194/bg-22-767-2025, 2025
Short summary
Short summary
This study analysed marine sediment samples from areas with and without minimal hydrocarbon seepage from reservoirs underneath. Depth profiles of dissolved chemical components in the pore water and molecular biological data revealed differences in microbial community composition and activity. These results indicate that even minor hydrocarbon seepage affects sedimentary biogeochemical cycling in marine sediments, potentially providing a new tool for the detection of hydrocarbon reservoirs.
Robin Klomp, Olga M. Żygadłowska, Mike S. M. Jetten, Véronique E. Oldham, Niels A. G. M. van Helmond, Caroline P. Slomp, and Wytze K. Lenstra
Biogeosciences, 22, 751–765, https://doi.org/10.5194/bg-22-751-2025, https://doi.org/10.5194/bg-22-751-2025, 2025
Short summary
Short summary
In marine sediments, dissolved Mn is present as either Mn(III) or Mn(II). We apply a reactive transport model to geochemical data for a seasonally anoxic and sulfidic coastal basin to determine the pathways of formation and removal of dissolved Mn(III) in the sediment. We demonstrate a critical role for reactions with Fe(II) and show evidence for substantial benthic release of dissolved Mn(III). Given the mobility of Mn(III), these findings have important implications for marine Mn cycling.
Amanda C. Semler and Anne E. Dekas
Biogeosciences, 22, 385–403, https://doi.org/10.5194/bg-22-385-2025, https://doi.org/10.5194/bg-22-385-2025, 2025
Short summary
Short summary
Marine hydrocarbon seeps typically host subsurface microorganisms capable of degrading methane before it is emitted to the water column. Here we describe a seep in Monterey Bay which virtually lacks known methanotrophs and where biological consumption of methane at depth is undetected. Our findings suggest that some seeps are missing this critical biofilter and that seeps may be a more significant source of methane to the water column than previously realized.
Frieda P. Giest, Maren Jenrich, Guido Grosse, Benjamin M. Jones, Kai Mangelsdorf, Torben Windirsch, and Jens Strauss
EGUsphere, https://doi.org/10.5194/egusphere-2024-3683, https://doi.org/10.5194/egusphere-2024-3683, 2024
Short summary
Short summary
Climate warming causes permafrost to thaw, releasing greenhouse gases and affecting ecosystems. We studied sediments from Arctic coastal landscapes, including land, lakes, lagoons, and the ocean, finding that organic carbon storage and quality vary with landscape features and saltwater influence. Freshwater and land areas store more carbon, while saltwater reduces its quality. These findings improve predictions of Arctic responses to climate change and their impact on global carbon cycling.
Thomas W. Garner, J. Andrew G. Cooper, Alan M. Smith, Gavin M. Rishworth, and Matt Forbes
Biogeosciences, 21, 4785–4807, https://doi.org/10.5194/bg-21-4785-2024, https://doi.org/10.5194/bg-21-4785-2024, 2024
Short summary
Short summary
There is a diverse and often conflicting suite of terminologies, classifications, and nomenclature applicable to the study of terrestrial carbonate deposits and microbialites (deposits that wholly or primarily accrete as a result of microbial activity). We review existing schemes, identify duplication and redundancy, and present a new integrated approach applicable to tufa microbialites on rock coasts.
Catherine Brenan, Markus Kienast, Vittorio Maselli, Christopher K. Algar, Benjamin Misiuk, and Craig J. Brown
Biogeosciences, 21, 4569–4586, https://doi.org/10.5194/bg-21-4569-2024, https://doi.org/10.5194/bg-21-4569-2024, 2024
Short summary
Short summary
Quantifying how much organic carbon is stored in seafloor sediments is key to assessing how human activities can accelerate the process of carbon storage at the seabed, an important consideration for climate change. This study uses seafloor sediment maps to model organic carbon content. Carbon estimates were 12 times higher when assuming the absence of detailed sediment maps, demonstrating that high-resolution seafloor mapping is critically important for improved estimates of organic carbon.
Sophie Hage, Megan L. Baker, Nathalie Babonneau, Guillaume Soulet, Bernard Dennielou, Ricardo Silva Jacinto, Robert G. Hilton, Valier Galy, François Baudin, Christophe Rabouille, Clément Vic, Sefa Sahin, Sanem Açikalin, and Peter J. Talling
Biogeosciences, 21, 4251–4272, https://doi.org/10.5194/bg-21-4251-2024, https://doi.org/10.5194/bg-21-4251-2024, 2024
Short summary
Short summary
The land-to-ocean flux of particulate organic carbon (POC) is difficult to measure, inhibiting accurate modeling of the global carbon cycle. Here, we quantify the POC flux between one of the largest rivers on Earth (Congo) and the ocean. POC in the form of vegetation and soil is transported by episodic submarine avalanches in a 1000 km long canyon at up to 5 km water depth. The POC flux induced by avalanches is at least 3 times greater than that induced by the background flow related to tides.
Vanessa M. Alfonso, Peter M. Groffman, Zhongqi Cheng, and David E. Seidemann
EGUsphere, https://doi.org/10.5194/egusphere-2024-1165, https://doi.org/10.5194/egusphere-2024-1165, 2024
Short summary
Short summary
This study sought to explore organic-mineral interactions by investigating the functional performance of exposed clays through measurements of biogeochemical processes occurring on these materials. Results indicate that ancient clays are contributing to contemporary biogeochemical processes at ecosystem and landscape scales by supporting an active microbial community and a wide range of nitrogen cycle processes encompassing mineralization, immobilization, nitrification, and denitrification.
Xuefeng Peng, David J. Yousavich, Annie Bourbonnais, Frank Wenzhöfer, Felix Janssen, Tina Treude, and David L. Valentine
Biogeosciences, 21, 3041–3052, https://doi.org/10.5194/bg-21-3041-2024, https://doi.org/10.5194/bg-21-3041-2024, 2024
Short summary
Short summary
Biologically available (fixed) nitrogen (N) is a limiting nutrient for life in the ocean. Under low-oxygen conditions, fixed N is either removed via denitrification or retained via dissimilatory nitrate reduction to ammonia (DNRA). Using in situ incubations in the Santa Barbara Basin, which undergoes seasonal anoxia, we found that benthic denitrification was the dominant nitrate reduction process, while nitrate availability and organic carbon content control the relative importance of DNRA.
Nicole Burdanowitz, Gerhard Schmiedl, Birgit Gaye, Philipp M. Munz, and Hartmut Schulz
Biogeosciences, 21, 1477–1499, https://doi.org/10.5194/bg-21-1477-2024, https://doi.org/10.5194/bg-21-1477-2024, 2024
Short summary
Short summary
We analyse benthic foraminifera, nitrogen isotopes and lipids in a sediment core from the Gulf of Oman to investigate how the oxygen minimum zone (OMZ) and bottom water (BW) oxygenation have reacted to climatic changes since 43 ka. The OMZ and BW deoxygenation was strong during the Holocene, but the OMZ was well ventilated during the LGM period. We found an unstable mode of oscillating oxygenation states, from moderately oxygenated in cold stadials to deoxygenated in warm interstadials in MIS 3.
Maxime Daviray, Emmanuelle Geslin, Nils Risgaard-Petersen, Vincent V. Scholz, Marie Fouet, and Edouard Metzger
Biogeosciences, 21, 911–928, https://doi.org/10.5194/bg-21-911-2024, https://doi.org/10.5194/bg-21-911-2024, 2024
Short summary
Short summary
Coastal marine sediments are subject to major acidification processes because of climate change and human activities, but these processes can also result from biotic activity. We studied the sediment acidifcation effect on benthic calcareous foraminifera in intertidal mudflats. The strong pH decrease in sediments probably caused by cable bacteria led to calcareous test dissolution of living and dead foraminifera, threatening the test preservation and their robustness as environmental proxies.
Sebastian J. E. Krause, Jiarui Liu, David J. Yousavich, DeMarcus Robinson, David W. Hoyt, Qianhui Qin, Frank Wenzhöfer, Felix Janssen, David L. Valentine, and Tina Treude
Biogeosciences, 20, 4377–4390, https://doi.org/10.5194/bg-20-4377-2023, https://doi.org/10.5194/bg-20-4377-2023, 2023
Short summary
Short summary
Methane is a potent greenhouse gas, and hence it is important to understand its sources and sinks in the environment. Here we present new data from organic-rich surface sediments below an oxygen minimum zone off the coast of California (Santa Barbara Basin) demonstrating the simultaneous microbial production and consumption of methane, which appears to be an important process preventing the build-up of methane in these sediments and the emission into the water column and atmosphere.
Sinan Xu, Bo Liu, Sandra Arndt, Sabine Kasten, and Zijun Wu
Biogeosciences, 20, 2251–2263, https://doi.org/10.5194/bg-20-2251-2023, https://doi.org/10.5194/bg-20-2251-2023, 2023
Short summary
Short summary
We use a reactive continuum model based on a lognormal distribution (l-RCM) to inversely determine model parameters μ and σ at 123 sites across the global ocean. Our results show organic matter (OM) reactivity is more than 3 orders of magnitude higher in shelf than in abyssal regions. In addition, OM reactivity is higher than predicted in some specific regions, yet the l-RCM can still capture OM reactivity features in these regions.
Christiane Schmidt, Emmanuelle Geslin, Joan M. Bernhard, Charlotte LeKieffre, Mette Marianne Svenning, Helene Roberge, Magali Schweizer, and Giuliana Panieri
Biogeosciences, 19, 3897–3909, https://doi.org/10.5194/bg-19-3897-2022, https://doi.org/10.5194/bg-19-3897-2022, 2022
Short summary
Short summary
This study is the first to show non-selective deposit feeding in the foraminifera Nonionella labradorica and the possible uptake of methanotrophic bacteria. We carried out a feeding experiment with a marine methanotroph to examine the ultrastructure of the cell and degradation vacuoles using transmission electron microscopy (TEM). The results revealed three putative methanotrophs at the outside of the cell/test, which could be taken up via non-targeted grazing in seeps or our experiment.
James P. J. Ward, Katharine R. Hendry, Sandra Arndt, Johan C. Faust, Felipe S. Freitas, Sian F. Henley, Jeffrey W. Krause, Christian März, Allyson C. Tessin, and Ruth L. Airs
Biogeosciences, 19, 3445–3467, https://doi.org/10.5194/bg-19-3445-2022, https://doi.org/10.5194/bg-19-3445-2022, 2022
Short summary
Short summary
The seafloor plays an important role in the cycling of silicon (Si), a key nutrient that promotes marine primary productivity. In our model study, we disentangle major controls on the seafloor Si cycle to better anticipate the impacts of continued warming and sea ice melt in the Barents Sea. We uncover a coupling of the iron redox and Si cycles, dissolution of lithogenic silicates, and authigenic clay formation, comprising a Si sink that could have implications for the Arctic Ocean Si budget.
Hanni Vigderovich, Werner Eckert, Michal Elul, Maxim Rubin-Blum, Marcus Elvert, and Orit Sivan
Biogeosciences, 19, 2313–2331, https://doi.org/10.5194/bg-19-2313-2022, https://doi.org/10.5194/bg-19-2313-2022, 2022
Short summary
Short summary
Anaerobic oxidation of methane (AOM) is one of the major processes limiting the release of the greenhouse gas methane from natural environments. Here we show that significant AOM exists in the methane zone of lake sediments in natural conditions and even after long-term (ca. 18 months) anaerobic slurry incubations with two stages. Methanogens were most likely responsible for oxidizing the methane, and humic substances and iron oxides are likely electron acceptors to support this oxidation.
Bjorn Sundby, Pierre Anschutz, Pascal Lecroart, and Alfonso Mucci
Biogeosciences, 19, 1421–1434, https://doi.org/10.5194/bg-19-1421-2022, https://doi.org/10.5194/bg-19-1421-2022, 2022
Short summary
Short summary
A glacial–interglacial methane-fuelled redistribution of reactive phosphorus between the oceanic and sedimentary phosphorus reservoirs can occur in the ocean when falling sea level lowers the pressure on the seafloor, destabilizes methane hydrates, and triggers the dissolution of P-bearing iron oxides. The mass of phosphate potentially mobilizable from the sediment is similar to the size of the current oceanic reservoir. Hence, this process may play a major role in the marine phosphorus cycle.
Florian Lauryssen, Philippe Crombé, Tom Maris, Elliot Van Maldegem, Marijn Van de Broek, Stijn Temmerman, and Erik Smolders
Biogeosciences, 19, 763–776, https://doi.org/10.5194/bg-19-763-2022, https://doi.org/10.5194/bg-19-763-2022, 2022
Short summary
Short summary
Surface waters in lowland regions have a poor surface water quality, mainly due to excess nutrients like phosphate. Therefore, we wanted to know the phosphate levels without humans, also called the pre-industrial background. Phosphate binds strongly to sediment particles, suspended in the river water. In this research we used sediments deposited by a river as an archive for surface water phosphate back to 1800 CE. Pre-industrial phosphate levels were estimated at one-third of the modern levels.
Gerard J. M. Versteegh, Andrea Koschinsky, Thomas Kuhn, Inken Preuss, and Sabine Kasten
Biogeosciences, 18, 4965–4984, https://doi.org/10.5194/bg-18-4965-2021, https://doi.org/10.5194/bg-18-4965-2021, 2021
Short summary
Short summary
Oxygen penetrates sediments not only from the ocean bottom waters but also from the basement. The impact of the latter is poorly understood. We show that this basement oxygen has a clear impact on the nitrogen cycle, the redox state, and the distribution of manganese, nickel cobalt and organic matter in the sediments. This is important for (1) global biogeochemical cycles, (2) understanding sedimentary life and (3) the interpretation of the sediment record to reconstruct the past.
Annika Fiskal, Eva Anthamatten, Longhui Deng, Xingguo Han, Lorenzo Lagostina, Anja Michel, Rong Zhu, Nathalie Dubois, Carsten J. Schubert, Stefano M. Bernasconi, and Mark A. Lever
Biogeosciences, 18, 4369–4388, https://doi.org/10.5194/bg-18-4369-2021, https://doi.org/10.5194/bg-18-4369-2021, 2021
Short summary
Short summary
Microbially produced methane can serve as a carbon source for freshwater macrofauna most likely through grazing on methane-oxidizing bacteria. This study investigates the contributions of different carbon sources to macrofaunal biomass. Our data suggest that the average contribution of methane-derived carbon is similar between different fauna but overall remains low. This is further supported by the low abundance of methane-cycling microorganisms.
Astrid Hylén, Sebastiaan J. van de Velde, Mikhail Kononets, Mingyue Luo, Elin Almroth-Rosell, and Per O. J. Hall
Biogeosciences, 18, 2981–3004, https://doi.org/10.5194/bg-18-2981-2021, https://doi.org/10.5194/bg-18-2981-2021, 2021
Short summary
Short summary
Sediments in oxygen-depleted ocean areas release high amounts of phosphorus, feeding algae that consume oxygen upon degradation, leading to further phosphorus release. Oxygenation is thought to trap phosphorus in the sediment and break this feedback. We studied the sediment phosphorus cycle in a previously anoxic area after an inflow of oxic water. Surprisingly, the sediment phosphorus release increased, showing that feedbacks between phosphorus release and oxygen depletion can be hard to break.
Sebastiaan J. van de Velde, Rebecca K. James, Ine Callebaut, Silvia Hidalgo-Martinez, and Filip J. R. Meysman
Biogeosciences, 18, 1451–1461, https://doi.org/10.5194/bg-18-1451-2021, https://doi.org/10.5194/bg-18-1451-2021, 2021
Short summary
Short summary
Some 540 Myr ago, animal life evolved in the ocean. Previous research suggested that when these early animals started inhabiting the seafloor, they retained phosphorus in the seafloor, thereby limiting photosynthesis in the ocean. We studied salt marsh sediments with and without animals and found that their impact on phosphorus retention is limited, which implies that their impact on the global environment might have been less drastic than previously assumed.
Martijn Hermans, Nils Risgaard-Petersen, Filip J. R. Meysman, and Caroline P. Slomp
Biogeosciences, 17, 5919–5938, https://doi.org/10.5194/bg-17-5919-2020, https://doi.org/10.5194/bg-17-5919-2020, 2020
Short summary
Short summary
This paper demonstrates that the recently discovered cable bacteria are capable of using a mineral, known as siderite, as a source for the formation of iron oxides. This work also demonstrates that the activity of cable bacteria can lead to a distinct subsurface layer in the sediment that can be used as a marker for their activity.
Torben Windirsch, Guido Grosse, Mathias Ulrich, Lutz Schirrmeister, Alexander N. Fedorov, Pavel Y. Konstantinov, Matthias Fuchs, Loeka L. Jongejans, Juliane Wolter, Thomas Opel, and Jens Strauss
Biogeosciences, 17, 3797–3814, https://doi.org/10.5194/bg-17-3797-2020, https://doi.org/10.5194/bg-17-3797-2020, 2020
Short summary
Short summary
To extend the knowledge on circumpolar deep permafrost carbon storage, we examined two deep permafrost deposit types (Yedoma and alas) in central Yakutia. We found little but partially undecomposed organic carbon as a result of largely changing sedimentation processes. The carbon stock of the examined Yedoma deposits is about 50 % lower than the general Yedoma domain mean, implying a very hetererogeneous Yedoma composition, while the alas is approximately 80 % below the thermokarst deposit mean.
Anna Plass, Christian Schlosser, Stefan Sommer, Andrew W. Dale, Eric P. Achterberg, and Florian Scholz
Biogeosciences, 17, 3685–3704, https://doi.org/10.5194/bg-17-3685-2020, https://doi.org/10.5194/bg-17-3685-2020, 2020
Short summary
Short summary
We compare the cycling of Fe and Cd in sulfidic sediments of the Peruvian oxygen minimum zone. Due to the contrasting solubility of their sulfide minerals, the sedimentary Fe release and Cd burial fluxes covary with spatial and temporal distributions of H2S. Depending on the solubility of their sulfide minerals, sedimentary trace metal fluxes will respond differently to ocean deoxygenation/expansion of H2S concentrations, which may change trace metal stoichiometry of upwelling water masses.
Biqing Zhu, Manuel Kübler, Melanie Ridoli, Daniel Breitenstein, and Martin H. Schroth
Biogeosciences, 17, 3613–3630, https://doi.org/10.5194/bg-17-3613-2020, https://doi.org/10.5194/bg-17-3613-2020, 2020
Short summary
Short summary
We provide evidence that the greenhouse gas methane (CH4) is enclosed in calcareous glacier-forefield sediments across Switzerland. Geochemical analyses confirmed that this ancient CH4 has its origin in the calcareous parent bedrock. Our estimate of the total quantity of CH4 enclosed in sediments across Switzerland indicates a large CH4 mass (~105 t CH4). We produced evidence that CH4 is stable in its enclosed state, but additional experiments are needed to elucidate its long-term fate.
Matteo Puglini, Victor Brovkin, Pierre Regnier, and Sandra Arndt
Biogeosciences, 17, 3247–3275, https://doi.org/10.5194/bg-17-3247-2020, https://doi.org/10.5194/bg-17-3247-2020, 2020
Short summary
Short summary
A reaction-transport model to assess the potential non-turbulent methane flux from the East Siberian Arctic sediments to water columns is applied here. We show that anaerobic oxidation of methane (AOM) is an efficient filter except for high values of sedimentation rate and advective flow, which enable considerable non-turbulent steady-state methane fluxes. Significant transient methane fluxes can also occur during the building-up phase of the AOM-performing biomass microbial community.
Kyle Delwiche, Junyao Gu, Harold Hemond, and Sarah P. Preheim
Biogeosciences, 17, 3135–3147, https://doi.org/10.5194/bg-17-3135-2020, https://doi.org/10.5194/bg-17-3135-2020, 2020
Short summary
Short summary
In this study, we investigate whether bubbles transport sediments containing arsenic and cyanobacteria from the bottom to the top of a polluted lake. We measured arsenic and cyanobacteria from bubble traps in the lake and from an experimental bubble column in the laboratory. We found that bubble transport was not an important source of arsenic in the surface waters but that bubbles could transport enough cyanobacteria to the surface to exacerbate harmful algal blooms.
Nathaniel Kemnitz, William M. Berelson, Douglas E. Hammond, Laura Morine, Maria Figueroa, Timothy W. Lyons, Simon Scharf, Nick Rollins, Elizabeth Petsios, Sydnie Lemieux, and Tina Treude
Biogeosciences, 17, 2381–2396, https://doi.org/10.5194/bg-17-2381-2020, https://doi.org/10.5194/bg-17-2381-2020, 2020
Short summary
Short summary
Our paper shows how sedimentation in a very low oxygen setting provides a unique record of environmental change. We look at the past 250 years through the filter of sediment accumulation via radioisotope dating and other physical and chemical analyses of these sediments. We conclude, remarkably, that there has been very little change in net sediment mass accumulation through the past 100–150 years, yet just prior to 1900 CE, sediments were accumulating at 50 %–70 % of today's rate.
Dario Fussmann, Avril Jean Elisabeth von Hoyningen-Huene, Andreas Reimer, Dominik Schneider, Hana Babková, Robert Peticzka, Andreas Maier, Gernot Arp, Rolf Daniel, and Patrick Meister
Biogeosciences, 17, 2085–2106, https://doi.org/10.5194/bg-17-2085-2020, https://doi.org/10.5194/bg-17-2085-2020, 2020
Short summary
Short summary
Dolomite (CaMg(CO3)2) is supersaturated in many aquatic settings (e.g., seawater) on modern Earth but does not precipitate directly from the fluid, a fact known as the dolomite problem. The widely acknowledged concept of dolomite precipitation involves microbial extracellular polymeric substances (EPSs) and anoxic conditions as important drivers. In contrast, results from Lake Neusiedl support an alternative concept of Ca–Mg carbonate precipitation under aerobic and alkaline conditions.
Aurèle Vuillemin, André Friese, Richard Wirth, Jan A. Schuessler, Anja M. Schleicher, Helga Kemnitz, Andreas Lücke, Kohen W. Bauer, Sulung Nomosatryo, Friedhelm von Blanckenburg, Rachel Simister, Luis G. Ordoñez, Daniel Ariztegui, Cynthia Henny, James M. Russell, Satria Bijaksana, Hendrik Vogel, Sean A. Crowe, Jens Kallmeyer, and the Towuti Drilling Project
Science team
Biogeosciences, 17, 1955–1973, https://doi.org/10.5194/bg-17-1955-2020, https://doi.org/10.5194/bg-17-1955-2020, 2020
Short summary
Short summary
Ferruginous lakes experience restricted primary production due to phosphorus trapping by ferric iron oxides under oxic conditions. We report the presence of large crystals of vivianite, a ferrous iron phosphate, in sediments from Lake Towuti, Indonesia. We address processes of P retention linked to diagenesis of iron phases. Vivianite crystals had light Fe2+ isotope signatures and contained mineral inclusions consistent with antecedent processes of microbial sulfate and iron reduction.
Sonja Geilert, Patricia Grasse, Kristin Doering, Klaus Wallmann, Claudia Ehlert, Florian Scholz, Martin Frank, Mark Schmidt, and Christian Hensen
Biogeosciences, 17, 1745–1763, https://doi.org/10.5194/bg-17-1745-2020, https://doi.org/10.5194/bg-17-1745-2020, 2020
Short summary
Short summary
Marine silicate weathering is a key process of the marine silica cycle; however, its controlling processes are not well understood. In the Guaymas Basin, silicate weathering has been studied under markedly differing ambient conditions. Environmental settings like redox conditions or terrigenous input of reactive silicates appear to be major factors controlling marine silicate weathering. These factors need to be taken into account in future oceanic mass balances of Si and in modeling studies.
Jessica B. Volz, Laura Haffert, Matthias Haeckel, Andrea Koschinsky, and Sabine Kasten
Biogeosciences, 17, 1113–1131, https://doi.org/10.5194/bg-17-1113-2020, https://doi.org/10.5194/bg-17-1113-2020, 2020
Short summary
Short summary
Potential future deep-sea mining of polymetallic nodules at the seafloor is expected to severely harm the marine environment. However, the consequences on deep-sea ecosystems are still poorly understood. This study on surface sediments from man-made disturbance tracks in the Pacific Ocean shows that due to the removal of the uppermost sediment layer and thereby the loss of organic matter, the geochemical system in the sediments is disturbed for millennia before reaching a new equilibrium.
Ralf Conrad, Melanie Klose, and Alex Enrich-Prast
Biogeosciences, 17, 1063–1069, https://doi.org/10.5194/bg-17-1063-2020, https://doi.org/10.5194/bg-17-1063-2020, 2020
Short summary
Short summary
Lake sediments release the greenhouse gas CH4. Acetate is an important precursor. Although Amazonian lake sediments all contained acetate-consuming methanogens, measurement of the turnover of labeled acetate showed that some sediments converted acetate not to CH4 plus CO2, as expected, but only to CO2. Our results indicate the operation of acetate-oxidizing microorganisms couples the oxidation process to syntrophic methanogenic partners and/or to the reduction of organic compounds.
Jens Rassmann, Eryn M. Eitel, Bruno Lansard, Cécile Cathalot, Christophe Brandily, Martial Taillefert, and Christophe Rabouille
Biogeosciences, 17, 13–33, https://doi.org/10.5194/bg-17-13-2020, https://doi.org/10.5194/bg-17-13-2020, 2020
Short summary
Short summary
In this paper, we use a large set of measurements made using in situ and lab techniques to elucidate the cause of dissolved inorganic carbon fluxes in sediments from the Rhône delta and its companion compound alkalinity, which carries the absorption capacity of coastal waters with respect to atmospheric CO2. We show that sediment processes (sulfate reduction, FeS precipitation and accumulation) are crucial in generating the alkalinity fluxes observed in this study by in situ incubation chambers.
Sophie A. L. Paul, Matthias Haeckel, Michael Bau, Rajina Bajracharya, and Andrea Koschinsky
Biogeosciences, 16, 4829–4849, https://doi.org/10.5194/bg-16-4829-2019, https://doi.org/10.5194/bg-16-4829-2019, 2019
Short summary
Short summary
We studied the upper 10 m of deep-sea sediments, including pore water, in the Peru Basin to understand small-scale variability of trace metals. Our results show high spatial variability related to topographical variations, which in turn impact organic matter contents, degradation processes, and trace metal cycling. Another interesting finding was the influence of dissolving buried nodules on the surrounding sediment and trace metal cycling.
Sarah Paradis, Antonio Pusceddu, Pere Masqué, Pere Puig, Davide Moccia, Tommaso Russo, and Claudio Lo Iacono
Biogeosciences, 16, 4307–4320, https://doi.org/10.5194/bg-16-4307-2019, https://doi.org/10.5194/bg-16-4307-2019, 2019
Short summary
Short summary
Chronic deep bottom trawling in the Gulf of Castellammare (SW Mediterranean) erodes large volumes of sediment, exposing over-century-old sediment depleted in organic matter. Nevertheless, the arrival of fresh and nutritious sediment recovers superficial organic matter in trawling grounds and leads to high turnover rates, partially and temporarily mitigating the impacts of bottom trawling. However, this deposition is ephemeral and it will be swiftly eroded by the passage of the next trawler.
Zhichao Zhou, Bo Liang, Li-Ying Wang, Jin-Feng Liu, Bo-Zhong Mu, Hojae Shim, and Ji-Dong Gu
Biogeosciences, 16, 4229–4241, https://doi.org/10.5194/bg-16-4229-2019, https://doi.org/10.5194/bg-16-4229-2019, 2019
Short summary
Short summary
This study shows a core bacterial microbiome with a small proportion of shared operational taxonomic units of common sequences among all oil reservoirs. Dominant methanogenesis shifts from the hydrogenotrophic pathway in water phase to the acetoclastic pathway in the oil phase at high temperatures, but the opposite is true at low temperatures. There are also major functional metabolism differences between the two phases for amino acids, hydrocarbons, and carbohydrates.
Annika Fiskal, Longhui Deng, Anja Michel, Philip Eickenbusch, Xingguo Han, Lorenzo Lagostina, Rong Zhu, Michael Sander, Martin H. Schroth, Stefano M. Bernasconi, Nathalie Dubois, and Mark A. Lever
Biogeosciences, 16, 3725–3746, https://doi.org/10.5194/bg-16-3725-2019, https://doi.org/10.5194/bg-16-3725-2019, 2019
Hanni Vigderovich, Lewen Liang, Barak Herut, Fengping Wang, Eyal Wurgaft, Maxim Rubin-Blum, and Orit Sivan
Biogeosciences, 16, 3165–3181, https://doi.org/10.5194/bg-16-3165-2019, https://doi.org/10.5194/bg-16-3165-2019, 2019
Short summary
Short summary
Microbial iron reduction participates in important biogeochemical cycles. In the last decade iron reduction has been observed in many aquatic sediments below its classical zone, in the methane production zone, suggesting a link between the two cycles. Here we present evidence for microbial iron reduction in the methanogenic depth of the oligotrophic SE Mediterranean continental shelf using mainly geochemical and microbial sedimentary profiles and suggest possible mechanisms for this process.
Haoyi Yao, Wei-Li Hong, Giuliana Panieri, Simone Sauer, Marta E. Torres, Moritz F. Lehmann, Friederike Gründger, and Helge Niemann
Biogeosciences, 16, 2221–2232, https://doi.org/10.5194/bg-16-2221-2019, https://doi.org/10.5194/bg-16-2221-2019, 2019
Short summary
Short summary
How methane is transported in the sediment is important for the microbial community living on methane. Here we report an observation of a mini-fracture that facilitates the advective gas transport of methane in the sediment, compared to the diffusive fluid transport without a fracture. We found contrasting bio-geochemical signals in these different transport modes. This finding can help to fill the gap in the fracture network system in modulating methane dynamics in surface sediments.
Laura A. Casella, Sixin He, Erika Griesshaber, Lourdes Fernández-Díaz, Martina Greiner, Elizabeth M. Harper, Daniel J. Jackson, Andreas Ziegler, Vasileios Mavromatis, Martin Dietzel, Anton Eisenhauer, Sabino Veintemillas-Verdaguer, Uwe Brand, and Wolfgang W. Schmahl
Biogeosciences, 15, 7451–7484, https://doi.org/10.5194/bg-15-7451-2018, https://doi.org/10.5194/bg-15-7451-2018, 2018
Short summary
Short summary
Biogenic carbonates record past environmental conditions. Fossil shell chemistry and microstructure change as metastable biogenic carbonates are replaced by inorganic calcite. Simulated diagenetic alteration at 175 °C of different shell microstructures showed that (nacreous) shell aragonite and calcite were partially replaced by coarse inorganic calcite crystals due to dissolution–reprecipitation reactions. EBSD maps allowed for qualitative assessment of the degree of diagenetic overprint.
Wytze K. Lenstra, Matthias Egger, Niels A. G. M. van Helmond, Emma Kritzberg, Daniel J. Conley, and Caroline P. Slomp
Biogeosciences, 15, 6979–6996, https://doi.org/10.5194/bg-15-6979-2018, https://doi.org/10.5194/bg-15-6979-2018, 2018
Short summary
Short summary
We show that burial rates of phosphorus (P) in an estuary in the northern Baltic Sea are very high. We demonstrate that at high sedimentation rates, P retention in the sediment is related to the formation of vivianite. With a reactive transport model, we assess the sensitivity of sedimentary vivianite formation. We suggest that enrichments of iron and P in the sediment are linked to periods of enhanced riverine input of Fe, which subsequently strongly enhances P burial in coastal sediments.
Jiarui Liu, Gareth Izon, Jiasheng Wang, Gilad Antler, Zhou Wang, Jie Zhao, and Matthias Egger
Biogeosciences, 15, 6329–6348, https://doi.org/10.5194/bg-15-6329-2018, https://doi.org/10.5194/bg-15-6329-2018, 2018
Short summary
Short summary
Our work provides new insights into the biogeochemical cycling of iron, methane and phosphorus. We found that vivianite, an iron-phosphate mineral, is pervasive in methane-rich sediments, suggesting that iron reduction at depth is coupled to phosphorus and methane cycling on a much greater spatial scale than previously assumed. Acting as an important burial mechanism for iron and phosphorus, vivianite authigenesis may be an under-considered process in both modern and ancient settings alike.
Marc A. Besseling, Ellen C. Hopmans, R. Christine Boschman, Jaap S. Sinninghe Damsté, and Laura Villanueva
Biogeosciences, 15, 4047–4064, https://doi.org/10.5194/bg-15-4047-2018, https://doi.org/10.5194/bg-15-4047-2018, 2018
Short summary
Short summary
Benthic archaea comprise a significant part of the total prokaryotic biomass in marine sediments. Here, we compared the archaeal diversity and intact polar lipid (IPL) composition in both surface and subsurface sediments with different oxygen regimes in the Arabian Sea oxygen minimum zone. The oxygenated sediments were dominated by Thaumarchaeota and IPL-GDGT-0. The anoxic sediment contained highly diverse archaeal communities and high relative abundances of IPL-GDGT-1 to -4.
Georgina Robinson, Thomas MacTavish, Candida Savage, Gary S. Caldwell, Clifford L. W. Jones, Trevor Probyn, Bradley D. Eyre, and Selina M. Stead
Biogeosciences, 15, 1863–1878, https://doi.org/10.5194/bg-15-1863-2018, https://doi.org/10.5194/bg-15-1863-2018, 2018
Short summary
Short summary
This study examined the effect of adding carbon to a sediment-based effluent treatment system to treat nitrogen-rich aquaculture waste. The research was conducted in incubation chambers to measure the exchange of gases and nutrients across the sediment–water interface and examine changes in the sediment microbial community. Adding carbon increased the amount of nitrogen retained in the treatment system, thereby reducing the levels of nitrogen needing to be discharged to the environment.
Daniele Brigolin, Christophe Rabouille, Bruno Bombled, Silvia Colla, Salvatrice Vizzini, Roberto Pastres, and Fabio Pranovi
Biogeosciences, 15, 1347–1366, https://doi.org/10.5194/bg-15-1347-2018, https://doi.org/10.5194/bg-15-1347-2018, 2018
Short summary
Short summary
We present the result of a study carried out in the north-western Adriatic Sea by combining two different types of models with field sampling. A mussel farm was taken as a local source of perturbation to the natural flux of particulate organic carbon to the sediment. Differences in fluxes were primarily associated with mussel physiological conditions. Although restricted, these changes in particulate organic carbon fluxes induced visible effects on sediment biogeochemistry.
Volker Brüchert, Lisa Bröder, Joanna E. Sawicka, Tommaso Tesi, Samantha P. Joye, Xiaole Sun, Igor P. Semiletov, and Vladimir A. Samarkin
Biogeosciences, 15, 471–490, https://doi.org/10.5194/bg-15-471-2018, https://doi.org/10.5194/bg-15-471-2018, 2018
Short summary
Short summary
We determined the aerobic and anaerobic degradation rates of land- and marine-derived organic material in East Siberian shelf sediment. Marine plankton-derived organic carbon was the main source for the oxic dissolved carbon dioxide production, whereas terrestrial organic material significantly contributed to the production of carbon dioxide under anoxic conditions. Our direct degradation rate measurements provide new constraints for the present-day Arctic marine carbon budget.
Jack J. Middelburg
Biogeosciences, 15, 413–427, https://doi.org/10.5194/bg-15-413-2018, https://doi.org/10.5194/bg-15-413-2018, 2018
Short summary
Short summary
Organic carbon processing at the seafloor is studied by geologists to better understand the sedimentary record, by biogeochemists to quantify burial and respiration, by organic geochemists to elucidate compositional changes, and by ecologists to follow carbon transfers within food webs. These disciplinary approaches have their strengths and weaknesses. This award talk provides a synthesis, highlights the role of animals in sediment carbon processing and presents some new concepts.
Perran Louis Miall Cook, Adam John Kessler, and Bradley David Eyre
Biogeosciences, 14, 4061–4069, https://doi.org/10.5194/bg-14-4061-2017, https://doi.org/10.5194/bg-14-4061-2017, 2017
Short summary
Short summary
Nitrogen is the key nutrient that typically limits productivity in coastal waters. One of the key controls on the amount of bioavailable nitrogen is the process of denitrification, which converts nitrate (bioavailable) into nitrogen gas. Previous studies suggest high rates of denitrification may take place within carbonate sediments, and one explanation for this is that this process may take place within the sand grains. Here we show evidence to support this hypothesis.
Cited articles
Aitkenhead, M. J. and Coull, M. C.: Mapping soil carbon stocks across Scotland using a neural network model, Geoderma, 262, 187–198, https://doi.org/10.1016/j.geoderma.2015.08.034, 2016.
Atamanchuk, D., Kononets, M., Thomas, P. J., Hovdenes, J., Tengberg, A., and Hall, P. O. J.: Continuous long-term observations of the carbonate system dynamics in the water column of a temperate fjord, J. Mar. Syst., 148, 272–284, https://doi.org/10.1016/j.jmarsys.2015.03.002, 2015.
Baltzer, A., Bates, R., Mokeddem, Z., Clet-Pellerin, M., Walter-Simonnet, A.-V., Bonnot-Courtois, C., and Austin, W. E. N.: Using seismic facies and pollen analyses to evaluate climatically driven change in a Scottish sea loch (fjord) over the last 20 ka, Geol. Soc. London, Spec. Publ., 344, 355–369, https://doi.org/10.1144/SP344.24, 2010.
Bauer, J. E. and Bianchi, T. S.: Dissolved Organic Carbon Cycling and Transformation, Elsevier Inc., Treatise on Estuarine and Coastal Science, 5, 7-762012, 2011.
Bauer, J. E., Cai, W.-J., Raymond, P. A, Bianchi, T. S., Hopkinson, C. S., and Regnier, P. A. G.: The changing carbon cycle of the coastal ocean., Nature, 504, 61–70, https://doi.org/10.1038/nature12857, 2013.
Bianchi, T. S.: The role of terrestrially derived organic carbon in the coastal ocean: a changing paradigm and the priming effect, P. Natl. Acad. Sci. USA, 108, 19473–19481, https://doi.org/10.1073/pnas.1017982108, 2011.
Bianchi, T. S., Schreiner, K. M., Smith, R. W., Burdige, D. J., Woodard, S., and Conley, D. J.: Redox Effects on Organic Matter Storage in Coastal Sediments During the Holocene?: A Biomarker / Proxy Perspective, Annu. Rev. Earth Pl. Sc., 44, 295–319, https://doi.org/10.1146/annurev-earth-060614-105417, 2016.
Bradley, R. I., Milne, R., Bell, J., Lilly, A., Jordan, C., and Higgins, A.: A soil carbon and land use database for the United Kingdom, Soil Use Manag., 21, 363–369, https://doi.org/10.1079/SUM2005351, 2005.
Brazier, V., Whittington, G., and Ballantyne, C. K.: Holocene debris cone evolution in glen etive Western Grampian Hhghlands, Scotland, Earth Surf. Proc. Land., 13, 525–531, 1988.
Burrows, M. T., Kamenos, N. A., Hughes D. J., Stahl, H., Howe, J. A., and Tett, P.: Assessment of carbon budgets and potential blue carbon stores in Scotland's coastal and marine environment. Scottish Natural Heritage Commissioned Report No. 761, available at: http://www.snh.org.uk/pdfs/publications/commissioned_reports/761.pdf (last access: 8 August 2017), 2014.
Cage, A. G. and Austin, W. E. N.: Marine climate variability during the last millennium: The Loch Sunart record, Scotland, UK, Quaternary Sci. Rev., 29, 1633–1647, https://doi.org/10.1016/j.quascirev.2010.01.014, 2010.
Chapman, S. J., Bell, J., Donnelly, D., and Lilly, A.: Carbon stocks in Scottish peatlands, Soil Use Manag., 25, 105–112, https://doi.org/10.1111/j.1475-2743.2009.00219.x, 2009.
Clark, C. D., Hughes, A. L. C., Greenwood, S. L., Jordan, C., and Petter, H.: Pattern and timing of retreat of the last British-Irish Ice Sheet, Quaternary Sci. Rev., 44, 112–146, https://doi.org/10.1016/j.quascirev.2010.07.019, 2012.
Cronin, J. R. and Tyler, I. D.: Organic carbon in a Scottish sea loch, in: Analytical Techniques in Environmental Chemistry, edited by: Albaiges, J., Pergamon Press, Oxford, 419–426, 1980.
Cui, X., Bianchi, T. S., Savage, C., and Smith, R. W.: Organic carbon burial in fjords: Terrestrial versus marine inputs, Earth Planet. Sc. Lett., 451, 41–50, https://doi.org/10.1016/j.epsl.2016.07.003, 2016.
Cummins, R., Donnelly, D., Nolan, A., Towers, W., Chapman, S., Grieve, I., and Birnie, R. V.: Peat erosion and the management of peatland habitats, Scottish Natural Heritage Commissioned Report No. 410, http://www.snh.org.uk/pdfs/publications/commissioned_reports/410.pdf (last access: 8 August 2017), 2011.
Dadey, K. A., Janecek, T., and Klaus, A.: Dry bulk density: its use and determination, Proceedings of the Ocean Drilling Program, Scientific Results, 126, 551–554, 1992.
Davies, G. M., Gray, A., Rein, G., and Legg, C. J.: Peat consumption and carbon loss due to smouldering wildfire in a temperate peatland, For. Ecol. Manage., 308, 169–177, 2013.
Dix, J. K. and Duck, R. W.: A high-resolution seismic stratigraphy from a Scottish sea loch and its implications for Loch Lomond Stadial deglaciation, 15, 645–656, 2000.
Duarte, C. M., Middelburg, J. J., and Caraco, N.: Major role of marine vegetation on the oceanic carbon cycle, Biogeosciences, 2, 1–8, https://doi.org/10.5194/bg-2-1-2005, 2005.
Edwards, A. and Sharples, F.: Scottish Sea Lochs: A Catalogue, Scottish Marine Biological Association/Nature Conservancy Council, Oban, 1986.
Edwards, K. J. and Whittington, G.: Lateglacial palaeoenvironmental investigations at Wester Cartmore Farm, Fife and their significance for patterns of vegetation and climate change in east-central Scotland, Rev. Palaeobot. Palyno., 159, 14–34, 2010.
Forestry Commission: Carbon in living woodland trees in Britain: A National Forestry Inventory Report, available at: http://www.forestry.gov.uk/pdf/FCNFI113.pdf/$FILE/FCNFI113.pdf, 2015.
Friedrich, J., Janssen, F., Aleynik, D., Bange, H. W., Boltacheva, N., Çagatay, M. N., Dale, A. W., Etiope, G., Erdem, Z., Geraga, M., Gilli, A., Gomoiu, M. T., Hall, P. O. J., Hansson, D., He, Y., Holtappels, M., Kirf, M. K., Kononets, M., Konovalov, S., Lichtschlag, A., Livingstone, D. M., Marinaro, G., Mazlumyan, S., Naeher, S., North, R. P., Papatheodorou, G., Pfannkuche, O., Prien, R., Rehder, G., Schubert, C. J., Soltwedel, T., Sommer, S., Stahl, H., Stanev, E. V., Teaca, A., Tengberg, A., Waldmann, C., Wehrli, B., and Wenzhöfer, F.: Investigating hypoxia in aquatic environments: diverse approaches to addressing a complex phenomenon, Biogeosciences, 11, 1215–1259, https://doi.org/10.5194/bg-11-1215-2014, 2014.
Gillibrand, P. A., Cage, A. G., and Austin, W. E. N.: A preliminary investigation of basin water response to climate forcing in a Scottish fjord: evaluating the influence of the NAO, Cont. Shelf Res., 25, 571–587, https://doi.org/10.1016/j.csr.2004.10.011, 2005.
Gillibrand, P. A., Cromey, C. J., Black, K. D., Inall, M. E., and Gontarek, S. J.: Identifying the risk of deoxygenation in Scottish sea lochs with isolated deep water, Scottish Aquaculture Research Forum, SARF 07 Report, 2006.
Golledge, N. R.: Glaciation of Scotland during the Younger Dryas stadial?: a review, J. Quat. Sci., 25, 550–566, https://doi.org/10.1002/jqs.1319, 2010.
Harris, D., Horwáth, W. R., and van Kessel, C.:, Acid fumigation of soils to remove carbonates prior to total organic carbon or carbon-13 isotopic analysis, Soil Sci. Soc. Am. J., 65, 1853–1856, 2001.
Henrys, P. A., Keith, A., and Wood, C. M.: Model estimates of aboveground carbon for Great Britain. NERC Environmental Information Data Centre, available at: https://doi.org/10.5285/9be652e7-d5ce-44c1-a5fc-8349f76f5f5c (last access: 10 August 2017), 2016.
Howe, J. A., Shimmield, T., Austin, W. E. N., and Longva, O.: Post-glacial depositional environments in a mid-high latitude glacially-overdeepened sea loch, inner Loch Etive, western Scotland, 185, 417–433, 2002.
Jackson, R. B., Banner, J. L., Jobbagy, E. G., Pockman, W. T., and Wall, D. H.: Ecosystem carbon loss with woody plant invasion of grasslands, Nature, 418, 623–626, 2012.
Khanna, N., Godbold, J. A., Austin, W. E. N., and Paterson, D. M.: The impact of ocean acidification on the functional morphology of foraminifera, PLoS One, 8, 10–13, https://doi.org/10.1371/journal.pone.0083118, 2013.
Lambeck, K.: Glacial rebound of the British Isles II. A high resolution high precsion model, Geophys. J. Int., 115, 960–990, 1993.
Loh, P. S., Miller, A. E. J., Reeves, A. D., Harvey, S. M., Overnell, J., and Systems, E.: Assessing the biodegradability of terrestrially-derived organic matter in Scottish sea loch sediments, 811–823, 2008.
Mastrandrea, M. D., Field, C. B., Stocker, T. F., Edenhofer, O., Ebi, K. L., Frame, D. J. Held, H., Kriegler, E., Mach, K. J., Matschoss, P. R., Plattner, G. K, Yohe, G. W., and Zwiers, F. W.: Guidance Note for Lead Authors of the IPCC Fifth Assessment Report on Consistent Treatment of Uncertainties, Intergovernmental Panel on Climate Change (IPCC), 2010.
McIntyre, K. L. and Howe, J. A.: Scottish west coast fjords since the last glaciation: a review, Geological Society, London, Special Publications, 344, 305–329, 2010.
Middelburg, J. J. and Levin, L. A.: Coastal hypoxia and sediment biogeochemistry, Biogeosciences, 6, 1273–1293, https://doi.org/10.5194/bg-6-1273-2009, 2009.
Middelburg, J. J., Vlug, T., Jaco, F., and van der Nat, W.: Organic matter mineralization in marine systems, Glob. Planet. Change, 8, 47–58, 1993.
Mokeddem, Z., Goubert, E., Lartaud, F., and Labourdette, N.: The “Turritella Layer”: A Potential Proxy of a Drastic Holocene Environmental Change on the North – East Atlantic Coast, in: Sediment Fluxes in Coastal Areas, 3–21, https://link.springer.com/chapter/10.1007/978-94-017-9260-8_1, 2015.
Nørgaard-Pedersen, N., Austin, W. E. N., Howe, J. A., and Shimmield, T.: The Holocene record of Loch Etive, western Scotland: Influence of catchment and relative sea level changes, Mar. Geol., 228, 55–71, https://doi.org/10.1016/j.margeo.2006.01.001, 2006.
Röhr, M. E., Boström, C., Canal-Vergés, P., and Holmer, M.: Blue carbon stocks in Baltic Sea eelgrass (Zostera marina) meadows, Biogeosciences, 13, 6139–6153, https://doi.org/10.5194/bg-13-6139-2016, 2016.
Russell, M., Robinson, C. D., Webster, L., Walsham, P., Phillips, L., Dalgarno, E., Rose, M., Watson, D., Scurfield, J., Avery, D. J., Devalla, S., Gubbins, M., Davies, I. M., and Moffat, C. F.: Persistent organic pollutants and trace metals in sediments close to Scottish marine fish farm, Scottish marine and freshwater science, 1, ISSN: 2043-7722, 2010.
Smeaton, C. and Austin, W. E. N.: Sources, sinks, and subsidies: Terrestrial carbon storage in mid-latitude fjords, J. Geophys. Res.-Biogeo., 122, https://doi.org/10.1002/2017JG003952, 2017.
Smeaton, C., Austin, W. E. N., Davies, A. L., Baltzer, A., Abell, R. E., and Howe, J. A.: Substantial stores of sedimentary carbon held in mid-latitude fjords, Biogeosciences, 13, 5771–5787, https://doi.org/10.5194/bg-13-5771-2016, 2016.
Smith, R. W., Bianchi, T. S., Allison, M., Savage, C., and Galy, V.: High rates of organic carbon burial in fjord sediments globally, Nat. Geosci., 8, 450–453, https://doi.org/10.1038/NGEO2421, 2015.
Stoker, M. and Bradwell, T.: Neotectonic deformation in a scottish fjord, Loch Broom, NW Scotland, Scot. J. Geol., 45, 107–116, 2009.
Stoker, M., Wilson, C. R., Howe J. A., Bradwell, T., and Long, D.: Paraglacial slope instability in Scottish fjords: Examples from Little Loch Broom, NW Scotland, Geological Society Special Publications, 344, 225–242, 2010
Syvitski, J. P. M. and Shaw, J.: Sedimentology and Geomorphology of Fjords, Geomorphology and Sedimentology of Estuaries, Dev. Sedimentology, 53, 113–178, 1995.
Syvitski, J. P. M., Burrell, D. C., and Skei, J. M.: Fjords, Processes and Products, Springer-Verlag, New York, 1987.
van der Heijden, L. H. and Kamenos, N. A.: Reviews and syntheses: Calculating the global contribution of coralline algae to total carbon burial, Biogeosciences, 12, 6429–6441, https://doi.org/10.5194/bg-12-6429-2015, 2015.
Vanguelova, E. I., Nisbet, T. R., Moffat, A. J., Broadmeadow, S., Sanders, T. G. M., and Morison, J. I. L.: A new evaluation of carbon stocks in British forest soils, Soil Use Manag., 29, 169–181, https://doi.org/10.1111/sum.12025, 2013.
Verardo, D. J., Froelich, P. N., and McIntyre, A.: Determination of organic carbon and nitrogen in marine sediments using the Carlo Erba NA-1500 Analyzer, Deep-Sea Res., 37, 157–165, 1990.
Webster, L., Fryer, R. J., Megginson, C., Dalgarno, E. J., Mcintosh, A. D., Moffat, C. F., Road, V., and Ab, U. K.: The polycyclic aromatic hydrocarbon and geochemical biomarker composition of sediments from sea lochs on the west coast of Scotland, J. Environ. Monit., 6, 219–228, 2004.
Woulds, C., Cowie, G. L., Levin, L. A., Andersson, J. H., Middelburg, J. J., Vandewiele, S., Lamont, P. A., Larkin, K. E., Gooday, A. J., Schumacher, S., Whitcraft, C., and Jeffreys, R. M.: Oxygen as a control on seafloor biological communities and their roles in sedimentary carbon cycling, Limnol. Oceanogr., 52, 1–13, 2007.
Woulds, C., Bouillon, S., Cowie, G. L., Drake, E., Middelburg, J. J., and Witte, U.: Patterns of carbon processing at the seafloor: the role of faunal and microbial communities in moderating carbon flows, Biogeosciences, 13, 4343–4357, https://doi.org/10.5194/bg-13-4343-2016, 2016.
Short summary
Fjord sediments are recognised as hotspots for the burial and long-term storage of carbon. In this study, we use the Scottish fjords as a natural laboratory. Using geophysical and geochemical analysis in combination with upscaling techniques, we have generated the first full national sedimentary C inventory for a fjordic system. The results indicate that the Scottish fjords on a like-for-like basis are more effective as C stores than their terrestrial counterparts, including Scottish peatlands.
Fjord sediments are recognised as hotspots for the burial and long-term storage of carbon. In...
Altmetrics
Final-revised paper
Preprint