Articles | Volume 10, issue 7
Biogeosciences, 10, 5019–5030, 2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article 25 Jul 2013
Research article | 25 Jul 2013
Spatiotemporal distributions of Fukushima-derived radionuclides in nearby marine surface sediments
M. Kusakabe et al.
S. Oikawa, H. Takata, T. Watabe, J. Misonoo, and M. Kusakabe
Biogeosciences, 10, 5031–5047,
S. Oikawa, H. Takata, T. Watabe, J. Misonoo, and M. Kusakabe
Biogeosciences, 10, 5031–5047,
Related subject area
Biogeochemistry: SedimentBiogeochemical impact of cable bacteria on coastal Black Sea sedimentBioturbation has a limited effect on phosphorus burial in salt marsh sedimentsOrganic carbon characteristics in ice-rich permafrost in alas and Yedoma deposits, central Yakutia, SiberiaThe control of hydrogen sulfide on benthic iron and cadmium fluxes in the oxygen minimum zone off PeruQuantity and distribution of methane entrapped in sediments of calcareous, Alpine glacier forefieldsAssessing the potential for non-turbulent methane escape from the East Siberian Arctic ShelfVertical transport of sediment-associated metals and cyanobacteria by ebullition in a stratified lakeEvidence of changes in sedimentation rate and sediment fabric in a low-oxygen setting: Santa Monica Basin, CAAuthigenic formation of Ca–Mg carbonates in the shallow alkaline Lake Neusiedl, AustriaVivianite formation in ferruginous sediments from Lake Towuti, IndonesiaImpact of ambient conditions on the Si isotope fractionation in marine pore fluids during early diagenesisImpact of small-scale disturbances on geochemical conditions, biogeochemical processes and element fluxes in surface sediments of the eastern Clarion–Clipperton Zone, Pacific OceanAcetate turnover and methanogenic pathways in Amazonian lake sedimentsBenthic alkalinity and dissolved inorganic carbon fluxes in the Rhône River prodelta generated by decoupled aerobic and anaerobic processesSmall-scale heterogeneity of trace metals including rare earth elements and yttrium in deep-sea sediments and porewaters of the Peru Basin, southeastern equatorial PacificOrganic 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 ChinaEffects of eutrophication on sedimentary organic carbon cycling in five temperate lakesEvidence for microbial iron reduction in the methanic sediments of the oligotrophic southeastern Mediterranean continental shelfFracture-controlled fluid transport supports microbial methane-oxidizing communities at Vestnesa RidgeHydrothermal alteration of aragonitic biocarbonates: assessment of micro- and nanostructural dissolution–reprecipitation and constraints of diagenetic overprint from quantitative statistical grain-area analysisLarge variations in iron input to an oligotrophic Baltic Sea estuary: impact on sedimentary phosphorus burialVivianite formation in methane-rich deep-sea sediments from the South China SeaBenthic archaea as potential sources of tetraether membrane lipids in sediments across an oxygen minimum zoneCarbon amendment stimulates benthic nitrogen cycling during the bioremediation of particulate aquaculture wasteModelling biogeochemical processes in sediments from the north-western Adriatic Sea: response to enhanced particulate organic carbon fluxesCarbon mineralization in Laptev and East Siberian sea shelf and slope sedimentReviews and syntheses: to the bottom of carbon processing at the seafloorScotland's forgotten carbon: a national assessment of mid-latitude fjord sedimentary carbon stocksDoes denitrification occur within porous carbonate sand grains?Sediment phosphorus speciation and mobility under dynamic redox conditionsPore water geochemistry along continental slopes north of the East Siberian Sea: inference of low methane concentrationsExperimental diagenesis: insights into aragonite to calcite transformation of Arctica islandica shells by hydrothermal treatmentManganese and iron reduction dominate organic carbon oxidation in surface sediments of the deep Ulleung Basin, East SeaCarbonate chemistry in sediment porewaters of the Rhône River delta driven by early diagenesis (northwestern Mediterranean)Anaerobic oxidation of methane alters sediment records of sulfur, iron and phosphorus in the Black SeaModerate topsoil erosion rates constrain the magnitude of the erosion-induced carbon sink and agricultural productivity losses on the Chinese Loess PlateauMassive asphalt deposits, oil seepage, and gas venting support abundant chemosynthetic communities at the Campeche Knolls, southern Gulf of MexicoPatterns of carbon processing at the seafloor: the role of faunal and microbial communities in moderating carbon flowsQuantitative sediment source attribution with compound-specific isotope analysis in a C3 plant-dominated catchment (central Switzerland)Benthic phosphorus cycling in the Peruvian oxygen minimum zoneMicrobial methanogenesis in the sulfate-reducing zone of surface sediments traversing the Peruvian marginNitrogen cycling in the deep sedimentary biosphere: nitrate isotopes in porewaters underlying the oligotrophic North AtlanticEfficiency and adaptability of the benthic methane filter at Quepos Slide cold seeps, offshore of Costa RicaTwo-dimensional distribution of living benthic foraminifera in anoxic sediment layers of an estuarine mudflat (Loire estuary, France)Effects of fluctuating hypoxia on benthic oxygen consumption in the Black Sea (Crimean shelf)Soil carbon and nitrogen erosion in forested catchments: implications for erosion-induced terrestrial carbon sequestrationMulti-molecular tracers of terrestrial carbon transfer across the pan-Arctic: comparison of hydrolyzable components with plant wax lipids and lignin phenolsEffects of temperature and organic pollution on nutrient cycling in marine sedimentsOrganic-matter quality of deep permafrost carbon – a study from Arctic Siberia
Martijn Hermans, Nils Risgaard-Petersen, Filip J. R. Meysman, and Caroline P. Slomp
Biogeosciences, 17, 5919–5938,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.
Sebastiaan J. van de Velde, Rebecca K. James, Ine Callebaut, Silvia Hidalgo-Martinez, and Filip J. R. Meysman
Revised manuscript accepted for BGShort summary
Some 540 million years 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.
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,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,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,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,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,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,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,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,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,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,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,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,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,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,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,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,
Hanni Vigderovich, Lewen Liang, Barak Herut, Fengping Wang, Eyal Wurgaft, Maxim Rubin-Blum, and Orit Sivan
Biogeosciences, 16, 3165–3181,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,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,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,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,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,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,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,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,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,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.
Craig Smeaton, William E. N. Austin, Althea L. Davies, Agnes Baltzer, John A. Howe, and John M. Baxter
Biogeosciences, 14, 5663–5674,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.
Perran Louis Miall Cook, Adam John Kessler, and Bradley David Eyre
Biogeosciences, 14, 4061–4069,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.
Chris T. Parsons, Fereidoun Rezanezhad, David W. O'Connell, and Philippe Van Cappellen
Biogeosciences, 14, 3585–3602,Short summary
Phosphorus (P) has accumulated in sediments due to past human activities. The re-release of this P to water contributes to the growth of harmful algal blooms. Our research improves our mechanistic understanding of how P is partitioned between different chemical forms and between sediment and water under dynamic conditions. We demonstrate that P trapped within iron minerals may be less mobile during anoxic conditions than previously thought due to reversible changes to P forms within sediment.
Clint M. Miller, Gerald R. Dickens, Martin Jakobsson, Carina Johansson, Andrey Koshurnikov, Matt O'Regan, Francesco Muschitiello, Christian Stranne, and Carl-Magnus Mörth
Biogeosciences, 14, 2929–2953,Short summary
Continental slopes north of the East Siberian Sea are assumed to hold large amounts of methane. We present pore water chemistry from the 2014 SWERUS-C3 expedition. These are among the first results generated from this vast climatically sensitive region, and they imply that abundant methane, including gas hydrates, do not characterize the East Siberian Sea slope or rise. This contradicts previous modeling and discussions, which due to the lack of data are almost entirely based assumption.
Laura A. Casella, Erika Griesshaber, Xiaofei Yin, Andreas Ziegler, Vasileios Mavromatis, Dirk Müller, Ann-Christine Ritter, Dorothee Hippler, Elizabeth M. Harper, Martin Dietzel, Adrian Immenhauser, Bernd R. Schöne, Lucia Angiolini, and Wolfgang W. Schmahl
Biogeosciences, 14, 1461–1492,Short summary
Mollusc shells record past environments. Fossil shell chemistry and microstructure change as metastable biogenic aragonite transforms to stable geogenic calcite. We simulated this alteration of Arctica islandica shells by hydrothermal treatments. Below 175 °C the shell aragonite survived for weeks. At 175 °C the replacement of the original material starts after 4 days and yields submillimetre-sized calcites preserving the macroscopic morphology as well as the original internal micromorphology.
Jung-Ho Hyun, Sung-Han Kim, Jin-Sook Mok, Hyeyoun Cho, Tongsup Lee, Verona Vandieken, and Bo Thamdrup
Biogeosciences, 14, 941–958,Short summary
The surface sediments of the Ulleung Basin (UB) in the East Sea are characterized by high organic carbon contents (> 2.5 %, dry wt.) and very high concentrations of Mn oxides (> 200 μmol cm−3) and Fe oxides (up to 100 μmol cm−3). For the first time in deep offshore sediments on the Asian margin with water depth over 2000 m, we report that Mn reduction and Fe reduction were the dominant organic carbon (Corg) oxidation pathways, comprising 45 % and 20 % of total Corg oxidation, respectively.
Jens Rassmann, Bruno Lansard, Lara Pozzato, and Christophe Rabouille
Biogeosciences, 13, 5379–5394,Short summary
In situ O2 and pH measurements as well as determination of porewater concentrations of dissolved inorganic carbon, total alkalinity, sulfate and calcium have been measured in the sediments of the Rhône prodelta. Biogeochemical activity decreased with distance from the river mouth. Oxic processes decreased the carbonate saturation state (Ω) by lowering pH, whereas anaerobic organic matter degradation, dominated by sulfate reduction, was accompanied by increasing Ω and carbonate precipitation.
Matthias Egger, Peter Kraal, Tom Jilbert, Fatimah Sulu-Gambari, Célia J. Sapart, Thomas Röckmann, and Caroline P. Slomp
Biogeosciences, 13, 5333–5355,Short summary
By combining detailed geochemical analyses with diagenetic modeling, we provide new insights into how methane dynamics may strongly overprint burial records of iron, sulfur and phosphorus in marine systems subject to changes in organic matter loading or water column salinity. A better understanding of these processes will improve our ability to read ancient sediment records and thus to predict the potential consequences of global warming and human-enhanced inputs of nutrients to the ocean.
Jianlin Zhao, Kristof Van Oost, Longqian Chen, and Gerard Govers
Biogeosciences, 13, 4735–4750,Short summary
We used a novel approach to reassess erosion rates on the CLP. We found that both current average topsoil erosion rates and the maximum magnitude of the erosion-induced carbon sink are overestimated on the CLP. Although average topsoil losses on the CLP are still high, a major increase in agricultural productivity occurred since 1980. Hence, erosion is currently not a direct threat to agricultural productivity on the CLP but the long-term effects of erosion on soil quality remain important.
Heiko Sahling, Christian Borowski, Elva Escobar-Briones, Adriana Gaytán-Caballero, Chieh-Wei Hsu, Markus Loher, Ian MacDonald, Yann Marcon, Thomas Pape, Miriam Römer, Maxim Rubin-Blum, Florence Schubotz, Daniel Smrzka, Gunter Wegener, and Gerhard Bohrmann
Biogeosciences, 13, 4491–4512,Short summary
We were excited about nature’s diversity when we discovered spectacular flows of heavy oil at the seafloor with the remotely operated vehicle QUEST 4000 m in Campeche Bay, southern Gulf of Mexico. Vigorous methane gas bubble emissions lead to massive gas hydrate deposits at water depth as deep as 3420 m. The hydrates formed metre-sized mounds at the seafloor that were densely overgrown by vestimentiferan tubeworms and other seep-typical organisms.
Clare Woulds, Steven Bouillon, Gregory L. Cowie, Emily Drake, Jack J. Middelburg, and Ursula Witte
Biogeosciences, 13, 4343–4357,Short summary
Estuarine sediments are important locations for carbon cycling and burial. We used tracer experiments to investigate how site conditions affect the way in which seafloor biological communities cycle carbon. We showed that while total respiration rates are primarily determined by temperature, total carbon processing by the biological community is strongly related to its biomass. Further, we saw a distinct pattern of carbon cycling in sandy sediment, in which uptake by bacteria dominates.
Christine Alewell, Axel Birkholz, Katrin Meusburger, Yael Schindler Wildhaber, and Lionel Mabit
Biogeosciences, 13, 1587–1596,Short summary
Origin of suspended sediments in rivers is of crucial importance for optimization of catchment management. Sediment source attribution to a lowland river in central Switzerland with compound specific stable isotopes analysis (CSIA) indicated that 65 % of the suspended sediments originated from agricultural land during base flow, while forest was the dominant source during high flow. We achieved significant differences in CSIA signature from land uses dominated by C3 plant cultivation.
Ulrike Lomnitz, Stefan Sommer, Andrew W. Dale, Carolin R. Löscher, Anna Noffke, Klaus Wallmann, and Christian Hensen
Biogeosciences, 13, 1367–1386,Short summary
The study presents a P budget including the P input from the water column, the P burial in the sediments, as well as the P release from the sediments. We found that the P input could not maintain the P release rates. Consideration of other P sources, e.g., terrigenous P and P released from the dissolution of Fe oxyhydroxides, showed that none of these can account for the missing P. Thus, it is likely that abundant sulfide-oxidizing bacteria release the missing P during our measurement period.
J. Maltby, S. Sommer, A. W. Dale, and T. Treude
Biogeosciences, 13, 283–299,Short summary
The concurrence of methanogenesis and sulfate reduction was investigated in surface sediments (0–25cm b.s.f.) traversing the Peruvian margin. Surface methanogenesis was mainly based on non-competitive substrates to avoid competition with sulfate reducers. Accordingly, surface methanogenesis was mainly controlled by the availability of labile organic matter. The high relevance of surface methanogenesis especially on the shelf indicates its underestimated role within benthic methane budgeting.
S. D. Wankel, C. Buchwald, W. Ziebis, C. B. Wenk, and M. F. Lehmann
Biogeosciences, 12, 7483–7502,Short summary
In the sediments underlying the global oligotrophic ocean, low levels of microbial activity persist, despite low input of organic matter from surface ocean productivity. Using measured nitrogen and oxygen isotopes of porewater nitrate we estimate the magnitude and extent of microbial nitrogen cycling. We find evidence for the overlap of both denitrification as well as autotrophic pathways such as nitrification and nitrogen fixation, pointing to a relatively large role for subsurface autotrophy.
P. Steeb, S. Krause, P. Linke, C. Hensen, A. W. Dale, M. Nuzzo, and T. Treude
Biogeosciences, 12, 6687–6706,Short summary
We combined field, laboratory (sediment-flow-through system) and numerical modeling work to investigate cold seep sediments at Quespos Slide, offshore of Costa Rica. The results demonstrated the efficiency of the benthic methane filter and provided an estimate for its response time (ca. 170 days) to changes in fluid fluxes.
A. Thibault de Chanvalon, E. Metzger, A. Mouret, F. Cesbron, J. Knoery, E. Rozuel, P. Launeau, M. P. Nardelli, F. J. Jorissen, and E. Geslin
Biogeosciences, 12, 6219–6234,Short summary
We present a new rapid and accurate protocol to simultaneously sample, in two dimensions, benthic living foraminifera at the centimetre scale and dissolved iron and phosphorus at the submillimetre scale. It was applied to a highly bioturbated site in a mudflat of the Loire estuary and showed that, in the suboxic zone, foraminifera are less affected by active burrows (i.e. reoxygenated) than by iron reactive hotspots. This unexpected result calls for a generalization of this new protocol.
A. Lichtschlag, D. Donis, F. Janssen, G. L. Jessen, M. Holtappels, F. Wenzhöfer, S. Mazlumyan, N. Sergeeva, C. Waldmann, and A. Boetius
Biogeosciences, 12, 5075–5092,
E. M. Stacy, S. C. Hart, C. T. Hunsaker, D. W. Johnson, and A. A. Berhe
Biogeosciences, 12, 4861–4874,Short summary
In the southern parts of the Sierra Nevada in California, we investigated erosion of carbon and nitrogen from low-order catchments. We found that eroded sediments were OM rich, with a potential for significant gaseous and dissolved loss of OM during transport or after depositional in downslope or downstream depositional landform positions.
X. Feng, Ö. Gustafsson, R. M. Holmes, J. E. Vonk, B. E. van Dongen, I. P. Semiletov, O. V. Dudarev, M. B. Yunker, R. W. Macdonald, D. B. Montluçon, and T. I. Eglinton
Biogeosciences, 12, 4841–4860,Short summary
Currently very few studies have examined the distribution and fate of hydrolyzable organic carbon (OC) in Arctic sediments, whose fate remains unclear in the context of climate change. Our study focuses on the source, distribution and fate of hydrolyzable OC as compared with plant wax lipids and lignin phenols in the sedimentary particles of nine Arctic and sub-Arctic rivers. This multi-molecular approach allows for a comprehensive investigation of terrestrial OC transfer via Arctic rivers.
C. Sanz-Lázaro, T. Valdemarsen, and M. Holmer
Biogeosciences, 12, 4565–4575,
J. Strauss, L. Schirrmeister, K. Mangelsdorf, L. Eichhorn, S. Wetterich, and U. Herzschuh
Biogeosciences, 12, 2227–2245,Short summary
Climatic warming is affecting permafrost, including decomposition of organic matter (OM). However, quantitative data for the quality of OM and its availability for decomposition is limited. We analyzed the quality of OM in late Pleistocene (Yedoma) and Holocene (thermokarst) deposits. A lack of depth trends reveals a constant quality of OM showing that permafrost acts like a freezer, preserving OM quality. This OM will be susceptible to decomposition under climatic warming.
Ambe, D., Kaeriyama, H., Shigenobu, Y., Fujimoto, K., Ono, T., Setou, T., and Watanabe, T.: Distribution of radioactive cesium in sea sediment and bottom boundary layer associated with the Fukushima Daiichi Nuclear Power Plant accident, 23th Ocean Engineering Symposium, JFOES/JASNAOE, 1–6, 2012 (in Japanese with English abstract).
Aoyagi, K. and Igarashi, S.: On the size distribution of sediments in the coastal sea of Fukushima Prefecture. Bull. Fukushima Pref. Fish. Exp. Stat., 8, 69–81, 1999 (in Japanese).
Aoyama, M., Tsumune, D., Uematsu, M., Kondo, F., and Hamajima, Y.: Temporal variation of 134Cs and 137Cs activities in surface water at stations along the coastline near the Fukushima Dai-ichi Nuclear Power Plant accident site, Japan. Geochem. J., 46, 321–325, 2012.
Bailly du Bois, P., Laguionie, P., Boust, D., Korsakissok, I., Didier, D., and Fievet, B.: Estimation of marine source-term following Fukushima Dai-ichi accident, J. Environ. Radioactiv., 114, 2–9, 2012.
Børrentzen, P. and Salbu, B.: Fixation of Cs to marine sediments estimated by a stochastic modeling approach, J. Environ. Radioact., 61, 1–20, 2002.
Buesseler, K. O., Jayne, S. R., Fisher, N. S., Rypina, I. I., Baumann, H., Baumann, Z., Breier, C. F., Douglass, E. M., George, J., Macdonald, A. M., Miyamoto, H., Nishikawa, J., Pike, S. M., and Yoshida, S.: Fukushima-derived radionuclides in the ocean and biota off Japan, P. Natl. Acad. Sci., 109, 5984–5988, 2012.
Chino, M., Nakayama, H., Nagai, H., Terada, H., Katata, G., and Yamazawa, H.: Preliminary estimation of release amounts of 131I and 137Cs accidentally discharged from the Fukushima Daiichi Nuclear Power Plant into the atmosphere, J. Nucl. Sci. Technol., 48, 1129–1134, 2011.
Fowler, S. W., Buat-Menard, P., Yokoyama, Y., Ballestra, S., Holm, E., and Nguyen, H. V.: Rapid removal of Chernobyl fallout from Mediterranean surface waters by biological activity, Nature, 329, 56–58, 1987.
IAEA: Sediment distribution coefficients and concentration factors for biota in the marine environment, Tech. Rep. Ser. No. 422, 2004.
IRSN: Impact on marine environment of radioactive releases resulting from the Fukushima-Daiichi nuclear accident. Institut de Radioprotection et de S\^ureté Nucléaire, 9 pp., www.irsn.fr/EN/news/Pages/201103_seism-in-japan.aspx, 2011.
Kawamura, H., Kobayashi, T., Furuno, A., In, T., Ishikawa, Y., Nakayama, T., Shima, S., and Awaji, T.: Preliminary numerical experiments on oceanic dispersion of 131I and 137Cs discharged into the ocean because of the Fukushima Daiichi Nuclear Power Plant disaster, J. Nucl. Sci. Technol., 48, 1349–1356, 2011.
Kusakabe, M. Ku, T. L., Harada, K., Taguchi, K., and Tsunogai, S.: Chernobyl radioactivity found in mid-water sediment trap interceptor in the N. Pacific and Bering Sea, Geophys. Res. Lett., 15, 44–47, 1988.
Masumoto, Y., Miyazawa, Y., Tsumune, D., Tsubono, T., Kobayashi, T., Kawamura, H., Estournel, C., Marsaleix, P., Lanerolle, L., Mehra, A., and Garraffo, Z. D.: 137Cs Released from the Fukushima Daiichi Nuclear Power Plant, Elements, 8, 207–212, 2012.
MEXT: Radioactivity measurement; Series No. 2, (http://www.kankyo-hoshano.go.jp/series/lib/No2.pdf), 2002 (in Japanese).
Oikawa, S., Takata, H., Watabe, T., Misonoo, J., and Kusakabe, M.: Distribution of the Fukushima-derived radionuclides in seawater in the Pacific off the coast of Miyagi, Fukushima, and Ibaraki Prefectures, Japan, Biogeosciences, 10, 5031–5047, https://doi.org/10.5194/bg-10-5031-2013, 2013.
Otosaka, S. and Kobayashi, T.: Sedimentation and remobilization of radiocesium in the coastal area of Ibaraki, 70 km south of the Fukushima Dai-ichi Nuclear Power Plant, Environ. Monit. Assess., 185, 5419–5433, https://doi.org/10.1007/s10661-012-2956-7, 2012.
Qin, H., Yokoyama, Y., Fan, Q., Iwatani, H., Tanaka, K., Sakaguchi, A., Kanai, Y., Zhu, J., Onda, Y., and Takahashi, Y.: Investigation of cesium adsorption on soil and sediment samples from Fukushima Prefecture by sequential extraction and EXAFS technique, Geochem. J., 46, 297–302, 2012.
Tsukada, H., Takeda, A., Hisamatsu, S., and Inaba, J.: Concentration and specific activity of fallout 137Cs in extracted and particle-size fractions of cultivated soils, J. Environ. Radioact., 99, 875–881, 2008.
Tsumune, D., Tsubono, T., Aoyama, M., and Hirose, K.: Distribution of oceanic 137Cs from the Fukushima Dai-ichi Nuclear Power Plant simulated numerically by a regional ocean model, J. Environ. Radioactiv., 111, 100–108, 2012.
Watanabe, T., Tsuchiya, N., Oura, Y., Ebihara, M., Inoue, C., Hirano, N., Yamada, R., Yamasaki, S., Okamoto, A., Nara, F. W., and Nunohara, K.: Distribution of artificial radionuclides (110 mAg, 129 mTe, 134Cs, 137Cs) in surface soils from Miyagi Prefecture, northeast Japan, following the 2011 Fukushima Dai-ichi Nuclear Power Plant accident, Geochem. J., 46, 279–285, 2012.
Yoshida, N. and Takahashi, Y.: Land-surface contamination by radionuclides from the Fukushima Daiichi Nuclear Power Plant accident, Elements, 8, 201–206, 2012.