Articles | Volume 11, issue 4
https://doi.org/10.5194/bg-11-1215-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-11-1215-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
27 Feb 2014
Research article |
| 27 Feb 2014
Investigating hypoxia in aquatic environments: diverse approaches to addressing a complex phenomenon
J. Friedrich
Helmholtz Zentrum Geesthacht Center for Materials and Coastal Research, Max-Planck Str. 1, 21502 Geesthacht, Germany
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
F. Janssen
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
Max Planck Institute for Marine Microbiology, Celsiusstr. 1, 28359 Bremen, Germany
D. Aleynik
Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, UK
H. W. Bange
GEOMAR Helmholtz Center for Ocean Research Kiel, Wischhofstrasse 1–3, 24148 Kiel, Germany
N. Boltacheva
A. O. Kovalevskiy Institute of Biology of Southern Seas, Nakhimov Av. 2, 99011 Sevastopol, Ukraine
M. N. Çagatay
Istanbul Technical University, EMCOL and Department of Geological Engineering, Maslak Sar\i yer, 34469 Istanbul, Turkey
A. W. Dale
GEOMAR Helmholtz Center for Ocean Research Kiel, Wischhofstrasse 1–3, 24148 Kiel, Germany
G. Etiope
Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma 2, Via di Vigna Murata 605, 143 Rome, Italy
Faculty of Environmental Science and Engineering, Babes-Bolyai University, Cluj-Napoca, Romania
Istanbul Technical University, EMCOL and Department of Geological Engineering, Maslak Sar\i yer, 34469 Istanbul, Turkey
present address: GEOMAR Helmholtz Center for Ocean Research Kiel, Wischhofstrasse 1–3, 24148 Kiel, Germany
M. Geraga
Laboratory of Marine Geology and Physical Oceanography, Department of Geology, University of Patras, 26504, Greece
ETH Zurich, Geological Institute, Sonneggstrasse 5, 8092 Zurich, Switzerland
M. T. Gomoiu
National Institute of Marine Geology and Geoecology, 304 Mamaia Boulevard, 8700 Constanta, Romania
P. O. J. Hall
University of Gothenburg, Dept. of Chemistry and Molecular Biology, Marine Chemistry, 412 96, Gothenburg, Sweden
D. Hansson
Swedish Institute for the Marine Environment, Seminariegatan 1F, 405 30, Gothenburg, Sweden
Y. He
Helmholtz Zentrum Geesthacht Center for Materials and Coastal Research, Max-Planck Str. 1, 21502 Geesthacht, Germany
present address: University of Kiel, Institute of Geosciences, Ludewig-Meyn-Str. 10, 24118 Kiel, Germany
M. Holtappels
Max Planck Institute for Marine Microbiology, Celsiusstr. 1, 28359 Bremen, Germany
M. K. Kirf
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Surface Waters – Research and Management, Seestrasse 79, 6047 Kastanienbaum, Switzerland
M. Kononets
University of Gothenburg, Dept. of Chemistry and Molecular Biology, Marine Chemistry, 412 96, Gothenburg, Sweden
S. Konovalov
Marine Hydrophysical Institute, Dept. Marine Biogeochemistry, Kapitanskaya St. 2, 99011 Sevastopol, Ukraine
A. Lichtschlag
Max Planck Institute for Marine Microbiology, Celsiusstr. 1, 28359 Bremen, Germany
present address: National Oceanography Centre, University of Southampton Waterfront Campus, European Way, Southampton, SO14 3ZH, UK
D. M. Livingstone
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and Drinking Water, Überlandstrasse 133, 8600 Dübendorf, Switzerland
G. Marinaro
Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma 2, Via di Vigna Murata 605, 143 Rome, Italy
S. Mazlumyan
A. O. Kovalevskiy Institute of Biology of Southern Seas, Nakhimov Av. 2, 99011 Sevastopol, Ukraine
S. Naeher
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Surface Waters – Research and Management, Seestrasse 79, 6047 Kastanienbaum, Switzerland
present address: Curtin University, WA-Organic and Isotope Geochemistry Center, G.P.O.~Box U1987, Perth, WA 6845, Australia
R. P. North
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and Drinking Water, Überlandstrasse 133, 8600 Dübendorf, Switzerland
present address: Helmholtz Zentrum Geesthacht Center for Materials and Coastal Research, Max-Planck Str. 1, 21502 Geesthacht, Germany
G. Papatheodorou
Laboratory of Marine Geology and Physical Oceanography, Department of Geology, University of Patras, 26504, Greece
O. Pfannkuche
GEOMAR Helmholtz Center for Ocean Research Kiel, Wischhofstrasse 1–3, 24148 Kiel, Germany
Leibniz Institute for Baltic Sea Research Warnemünde, Seestr. 15, 18119 Rostock, Germany
G. Rehder
Leibniz Institute for Baltic Sea Research Warnemünde, Seestr. 15, 18119 Rostock, Germany
C. J. Schubert
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Surface Waters – Research and Management, Seestrasse 79, 6047 Kastanienbaum, Switzerland
T. Soltwedel
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
S. Sommer
GEOMAR Helmholtz Center for Ocean Research Kiel, Wischhofstrasse 1–3, 24148 Kiel, Germany
H. Stahl
Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, UK
E. V. Stanev
Helmholtz Zentrum Geesthacht Center for Materials and Coastal Research, Max-Planck Str. 1, 21502 Geesthacht, Germany
A. Teaca
National Institute of Marine Geology and Geoecology, 304 Mamaia Boulevard, 8700 Constanta, Romania
A. Tengberg
University of Gothenburg, Dept. of Chemistry and Molecular Biology, Marine Chemistry, 412 96, Gothenburg, Sweden
C. Waldmann
Bremen University/MARUM, Leobener Str., 28359 Bremen, Germany
B. Wehrli
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Surface Waters – Research and Management, Seestrasse 79, 6047 Kastanienbaum, Switzerland
F. Wenzhöfer
Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
Max Planck Institute for Marine Microbiology, Celsiusstr. 1, 28359 Bremen, Germany
Related authors
Alexander Bratek, Justus E. E. van
Beusekom, Andreas Neumann, Tina Sanders, Jana Friedrich, Kay-Christian Emeis, and Kirstin Dähnke
Biogeosciences, 17, 2839–2851, https://doi.org/10.5194/bg-17-2839-2020, https://doi.org/10.5194/bg-17-2839-2020, 2020
Short summary
Short summary
The following paper highlights the importance of benthic N-transformation rates in different sediment types in the southern North Sea as a source of fixed nitrogen for primary producers and also as a sink of fixed nitrogen. Sedimentary fluxes of dissolved inorganic nitrogen support ∼7 to 59 % of the average annual primary production. Semi-permeable and permeable sediments contribute ∼68 % of the total benthic N2 production rates, counteracting eutrophication in the southern North Sea.
Burkard Baschek, Friedhelm Schroeder, Holger Brix, Rolf Riethmüller, Thomas H. Badewien, Gisbert Breitbach, Bernd Brügge, Franciscus Colijn, Roland Doerffer, Christiane Eschenbach, Jana Friedrich, Philipp Fischer, Stefan Garthe, Jochen Horstmann, Hajo Krasemann, Katja Metfies, Lucas Merckelbach, Nino Ohle, Wilhelm Petersen, Daniel Pröfrock, Rüdiger Röttgers, Michael Schlüter, Jan Schulz, Johannes Schulz-Stellenfleth, Emil Stanev, Joanna Staneva, Christian Winter, Kai Wirtz, Jochen Wollschläger, Oliver Zielinski, and Friedwart Ziemer
Ocean Sci., 13, 379–410, https://doi.org/10.5194/os-13-379-2017, https://doi.org/10.5194/os-13-379-2017, 2017
Short summary
Short summary
The Coastal Observing System for Northern and Arctic Seas (COSYNA) was established in order to better understand the complex interdisciplinary processes of northern seas and the Arctic coasts in a changing environment. Particular focus is given to the heavily used German Bight in the North Sea. The automated observing and modelling system is designed to monitor real-time conditions, to provide short-term forecasts and data products, and to assess the impact of anthropogenically induced change.
Gesa Schulz, Kirstin Dähnke, Tina Sanders, Jan Penopp, Hermann W. Bange, Rena Czeschel, and Birgit Gaye
EGUsphere, https://doi.org/10.5194/egusphere-2025-1660, https://doi.org/10.5194/egusphere-2025-1660, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
Oxygen minimum zones (OMZs) are low-oxygen ocean areas that deplete nitrogen, a key marine nutrient. Understanding nitrogen cycling in OMZs is crucial for the global nitrogen cycle. This study examined nitrogen cycling in the OMZ of the Bay of Bengal and East Equatorial Indian Ocean, revealing limited mixing between both regions. Surface phytoplankton consumes nitrate, while deeper nitrification recycles nitrogen. In the BoB’s OMZ (100–300 m), nitrogen loss likely occurs via anammox.
Peter K. Bijl, Kasia K. Sliwinska, Bella Duncan, Arnaud Huguet, Sebastian Naeher, Ronnakrit Rattanasriampaipong, Claudia Sosa-Montes de Oca, Alexandra Auderset, Melissa Berke, Bum Soo Kim, Nina Davtian, Tom Dunkley Jones, Desmond Eefting, Felix Elling, Lauren O'Connor, Richard D. Pancost, Francien Peterse, Fenies Pierrick, Addison Rice, Appy Sluijs, Devika Varma, Wenjie Xiao, and Yige Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2025-1467, https://doi.org/10.5194/egusphere-2025-1467, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
Many academic laboratories worldwide process environmental samples for analysis of membrane lipid molecules of archaea, for the reconstruction of past environmental conditions. However, the sample workup scheme involves many steps, each of which has a risk of contamination or bias, affecting the results. This paper reviews steps involved in sampling, extraction and analysis of lipids, interpretation and archiving of the data. This ensures reproducable, reusable, comparable and consistent data.
Szabina Karancz, Lennart J. de Nooijer, Bas van der Wagt, Marcel T. J. van der Meer, Sambuddha Misra, Rick Hennekam, Zeynep Erdem, Julie Lattaud, Negar Haghipour, Stefan Schouten, and Gert-Jan Reichart
Clim. Past, 21, 679–704, https://doi.org/10.5194/cp-21-679-2025, https://doi.org/10.5194/cp-21-679-2025, 2025
Short summary
Short summary
Changes in upwelling intensity of the Benguela upwelling region during the last glacial motivated us to investigate the local CO2 history during the last glacial-to-interglacial transition. Using various geochemical tracers on archives from both subsurface and surface waters reveals enhanced storage of carbon at depth during the Last Glacial Maximum. An efficient biological pump likely prevented outgassing of CO2 from intermediate depth to the atmosphere.
Astrid Hylen, Nils Ekeroth, Hannah Berk, Andy W. Dale, Mikhail Kononets, Wytze K. Lenstra, Aada Palo, Anders Tengberg, Sebastiaan J. van de Velde, Stefan Sommer, Caroline P. Slomp, and Per O. J. Hall
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2025-146, https://doi.org/10.5194/essd-2025-146, 2025
Preprint under review for ESSD
Short summary
Short summary
Phosphorus is an essential element for life and its cycling strongly impact primary production. Here, we present a dataset of sediment-water fluxes of dissolved inorganic phosphorus from the Baltic Sea, an area with a long history of eutrophication. The fluxes were measured in situ with three types of benthic chamber landers at 59 stations over 20 years. The data show clear spatial patterns and will be important for marine management and studies on mechanisms in benthic phosphorus cycling.
Marjolaine Verret, Sebastian Naeher, Denis Lacelle, Catherine Ginnane, Warren Dickinson, Kevin Norton, Jocelyn Turnbull, and Richard Levy
EGUsphere, https://doi.org/10.5194/egusphere-2025-786, https://doi.org/10.5194/egusphere-2025-786, 2025
Short summary
Short summary
15 million years ago, the McMurdo Dry Valleys of Antarctica were dominated by a tundra environment. In contrast, the modern environment is amongst the coldest and driest on Earth. Using a permafrost core, this paper investigates the shift from a tundra- to a bacteria-dominated landscape. By differentiating between ancient and modern organic material, we further our understanding of preservation of ancient organic material and its response and contribution to future climate change.
Babette A.A. Hoogakker, Catherine Davis, Yi Wang, Stephanie Kusch, Katrina Nilsson-Kerr, Dalton S. Hardisty, Allison Jacobel, Dharma Reyes Macaya, Nicolaas Glock, Sha Ni, Julio Sepúlveda, Abby Ren, Alexandra Auderset, Anya V. Hess, Katrin J. Meissner, Jorge Cardich, Robert Anderson, Christine Barras, Chandranath Basak, Harold J. Bradbury, Inda Brinkmann, Alexis Castillo, Madelyn Cook, Kassandra Costa, Constance Choquel, Paula Diz, Jonas Donnenfield, Felix J. Elling, Zeynep Erdem, Helena L. Filipsson, Sebastián Garrido, Julia Gottschalk, Anjaly Govindankutty Menon, Jeroen Groeneveld, Christian Hallmann, Ingrid Hendy, Rick Hennekam, Wanyi Lu, Jean Lynch-Stieglitz, Lélia Matos, Alfredo Martínez-García, Giulia Molina, Práxedes Muñoz, Simone Moretti, Jennifer Morford, Sophie Nuber, Svetlana Radionovskaya, Morgan Reed Raven, Christopher J. Somes, Anja S. Studer, Kazuyo Tachikawa, Raúl Tapia, Martin Tetard, Tyler Vollmer, Xingchen Wang, Shuzhuang Wu, Yan Zhang, Xin-Yuan Zheng, and Yuxin Zhou
Biogeosciences, 22, 863–957, https://doi.org/10.5194/bg-22-863-2025, https://doi.org/10.5194/bg-22-863-2025, 2025
Short summary
Short summary
Paleo-oxygen proxies can extend current records, constrain pre-anthropogenic baselines, provide datasets necessary to test climate models under different boundary conditions, and ultimately understand how ocean oxygenation responds on longer timescales. Here we summarize current proxies used for the reconstruction of Cenozoic seawater oxygen levels. This includes an overview of the proxy's history, how it works, resources required, limitations, and future recommendations.
Guangyi Su, Julie Tolu, Clemens Glombitza, Jakob Zopfi, Moritz F. Lehmann, Mark A. Lever, and Carsten J. Schubert
EGUsphere, https://doi.org/10.5194/egusphere-2025-437, https://doi.org/10.5194/egusphere-2025-437, 2025
Short summary
Short summary
In Lake Geneva, we studied how different types of organic matter affect methane production. Despite varying sources—like algae and land-based materials, both deep and delta areas are significant methane sources and methane was mainly produced through CO2 reduction. Surprisingly, the origin of organic matter didn’t strongly influence methane production rates or pathways. Our findings highlight the need to better understand microbial processes to predict methane emissions from lakes.
Sigrid van Grinsven, Natsumi Maeda, Clemens Glombitza, Mark A. Lever, and Carsten J. Schubert
EGUsphere, https://doi.org/10.5194/egusphere-2024-3979, https://doi.org/10.5194/egusphere-2024-3979, 2025
Preprint archived
Short summary
Short summary
Algal blooms in lakes can cause large amounts of organic material to sink to the bottom, leading to low oxygen conditions and increased methane emissions. This study shows that adding oxygen to the bottom waters reduces methane emissions by 50 %, even after oxygen levels drop again. The effect was consistent across lakes with different nutrient levels. These findings suggest that oxygenation could be an effective strategy to reduce methane emissions in lakes.
Johnathan Daniel Maxey, Neil D. Hartstein, Hermann W. Bange, and Moritz Müller
Biogeosciences, 21, 5613–5637, https://doi.org/10.5194/bg-21-5613-2024, https://doi.org/10.5194/bg-21-5613-2024, 2024
Short summary
Short summary
The distribution of N2O in fjord-like estuaries is poorly described in the Southern Hemisphere. Our study describes N2O distribution and its drivers in one such system in Macquarie Harbour, Tasmania. Water samples were collected seasonally in 2022 and 2023. Results show the system removes atmospheric N2O when river flow is high, whereas the system emits N2O when the river flow is low. N2O generated in basins is intercepted by the surface water and exported to the ocean during high river flow.
Daniel Pönisch, Henry C. Bittig, Martin Kolbe, Ingo Schuffenhauer, Stefan Otto, Peter Holtermann, Kusala Premaratne, and Gregor Rehder
EGUsphere, https://doi.org/10.5194/egusphere-2024-3246, https://doi.org/10.5194/egusphere-2024-3246, 2024
Short summary
Short summary
Rewetted peatlands exhibit natural spatial and temporal biogeochemical heterogeneity, influenced by water level and vegetation. This study investigated the variability of the distribution of GHGs in a brackish-rewetted peatland. Two innovative sensor-equipped landers were used to measure a wide range of marine physicochemical variables at high temporal resolution. The measurements revealed strong fluctuations in CO2 and CH4, expressed as multi-day, diurnal and event-based variability.
Silvie Lainela, Erik Jacobs, Stella-Theresa Luik, Gregor Rehder, and Urmas Lips
Biogeosciences, 21, 4495–4519, https://doi.org/10.5194/bg-21-4495-2024, https://doi.org/10.5194/bg-21-4495-2024, 2024
Short summary
Short summary
We evaluate the variability of carbon dioxide and methane in the surface layer of the north-eastern basins of the Baltic Sea in 2018. We show that the shallower coastal areas have considerably higher spatial variability and seasonal amplitude of surface layer pCO2 and cCH4 than measured in the offshore areas of the Baltic Sea. Despite this high variability, caused mostly by coastal physical processes, the average annual air–sea CO2 fluxes differed only marginally between the sub-basins.
Riel Carlo O. Ingeniero, Gesa Schulz, and Hermann W. Bange
Biogeosciences, 21, 3425–3440, https://doi.org/10.5194/bg-21-3425-2024, https://doi.org/10.5194/bg-21-3425-2024, 2024
Short summary
Short summary
Our research is the first to measure dissolved NO concentrations in temperate estuarine waters, providing insights into its distribution under varying conditions and enhancing our understanding of its production processes. Dissolved NO was supersaturated in the Elbe Estuary, indicating that it is a source of atmospheric NO. The observed distribution of dissolved NO most likely resulted from nitrification.
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.
Hanqin Tian, Naiqing Pan, Rona L. Thompson, Josep G. Canadell, Parvadha Suntharalingam, Pierre Regnier, Eric A. Davidson, Michael Prather, Philippe Ciais, Marilena Muntean, Shufen Pan, Wilfried Winiwarter, Sönke Zaehle, Feng Zhou, Robert B. Jackson, Hermann W. Bange, Sarah Berthet, Zihao Bian, Daniele Bianchi, Alexander F. Bouwman, Erik T. Buitenhuis, Geoffrey Dutton, Minpeng Hu, Akihiko Ito, Atul K. Jain, Aurich Jeltsch-Thömmes, Fortunat Joos, Sian Kou-Giesbrecht, Paul B. Krummel, Xin Lan, Angela Landolfi, Ronny Lauerwald, Ya Li, Chaoqun Lu, Taylor Maavara, Manfredi Manizza, Dylan B. Millet, Jens Mühle, Prabir K. Patra, Glen P. Peters, Xiaoyu Qin, Peter Raymond, Laure Resplandy, Judith A. Rosentreter, Hao Shi, Qing Sun, Daniele Tonina, Francesco N. Tubiello, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Kelley C. Wells, Luke M. Western, Chris Wilson, Jia Yang, Yuanzhi Yao, Yongfa You, and Qing Zhu
Earth Syst. Sci. Data, 16, 2543–2604, https://doi.org/10.5194/essd-16-2543-2024, https://doi.org/10.5194/essd-16-2543-2024, 2024
Short summary
Short summary
Atmospheric concentrations of nitrous oxide (N2O), a greenhouse gas 273 times more potent than carbon dioxide, have increased by 25 % since the preindustrial period, with the highest observed growth rate in 2020 and 2021. This rapid growth rate has primarily been due to a 40 % increase in anthropogenic emissions since 1980. Observed atmospheric N2O concentrations in recent years have exceeded the worst-case climate scenario, underscoring the importance of reducing anthropogenic N2O emissions.
Zoë Rebecca van Kemenade, Zeynep Erdem, Ellen Christine Hopmans, Jaap Smede Sinninghe Damsté, and Darci Rush
Biogeosciences, 21, 1517–1532, https://doi.org/10.5194/bg-21-1517-2024, https://doi.org/10.5194/bg-21-1517-2024, 2024
Short summary
Short summary
The California Current system (CCS) hosts the eastern subtropical North Pacific oxygen minimum zone (ESTNP OMZ). This study shows anaerobic ammonium oxidizing (anammox) bacteria cause a loss of bioavailable nitrogen (N) in the ESTNP OMZ throughout the late Quaternary. Anammox occurred during both glacial and interglacial periods and was driven by the supply of organic matter and changes in ocean currents. These findings may have important consequences for biogeochemical models of the CCS.
De'Marcus Robinson, Anh L. D. Pham, David J. Yousavich, Felix Janssen, Frank Wenzhöfer, Eleanor C. Arrington, Kelsey M. Gosselin, Marco Sandoval-Belmar, Matthew Mar, David L. Valentine, Daniele Bianchi, and Tina Treude
Biogeosciences, 21, 773–788, https://doi.org/10.5194/bg-21-773-2024, https://doi.org/10.5194/bg-21-773-2024, 2024
Short summary
Short summary
The present study suggests that high release of ferrous iron from the seafloor of the oxygen-deficient Santa Barabara Basin (California) supports surface primary productivity, creating positive feedback on seafloor iron release by enhancing low-oxygen conditions in the basin.
David J. Yousavich, De'Marcus Robinson, Xuefeng Peng, Sebastian J. E. Krause, Frank Wenzhöfer, Felix Janssen, Na Liu, Jonathan Tarn, Franklin Kinnaman, David L. Valentine, and Tina Treude
Biogeosciences, 21, 789–809, https://doi.org/10.5194/bg-21-789-2024, https://doi.org/10.5194/bg-21-789-2024, 2024
Short summary
Short summary
Declining oxygen (O2) concentrations in coastal oceans can threaten people’s ways of life and food supplies. Here, we investigate how mats of bacteria that proliferate on the seafloor of the Santa Barbara Basin sustain and potentially worsen these O2 depletion events through their unique chemoautotrophic metabolism. Our study shows how changes in seafloor microbiology and geochemistry brought on by declining O2 concentrations can help these mats grow as well as how that growth affects the basin.
Henry C. Bittig, Erik Jacobs, Thomas Neumann, and Gregor Rehder
Earth Syst. Sci. Data, 16, 753–773, https://doi.org/10.5194/essd-16-753-2024, https://doi.org/10.5194/essd-16-753-2024, 2024
Short summary
Short summary
We present a pCO2 climatology of the Baltic Sea using a new approach to extrapolate from individual observations to the entire Baltic Sea. The extrapolation approach uses (a) a model to inform on how data at one location are connected to data at other locations, together with (b) very accurate pCO2 observations from 2003 to 2021 as the base data. The climatology can be used e.g. to assess uptake and release of CO2 or to identify extreme events.
Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Dorothee C. E. Bakker, Judith Hauck, Peter Landschützer, Corinne Le Quéré, Ingrid T. Luijkx, Glen P. Peters, Wouter Peters, Julia Pongratz, Clemens Schwingshackl, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone R. Alin, Peter Anthoni, Leticia Barbero, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Bertrand Decharme, Laurent Bopp, Ida Bagus Mandhara Brasika, Patricia Cadule, Matthew A. Chamberlain, Naveen Chandra, Thi-Tuyet-Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Xinyu Dou, Kazutaka Enyo, Wiley Evans, Stefanie Falk, Richard A. Feely, Liang Feng, Daniel J. Ford, Thomas Gasser, Josefine Ghattas, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Matthew Hefner, Jens Heinke, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Andrew R. Jacobson, Atul Jain, Tereza Jarníková, Annika Jersild, Fei Jiang, Zhe Jin, Fortunat Joos, Etsushi Kato, Ralph F. Keeling, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Xin Lan, Nathalie Lefèvre, Hongmei Li, Junjie Liu, Zhiqiang Liu, Lei Ma, Greg Marland, Nicolas Mayot, Patrick C. McGuire, Galen A. McKinley, Gesa Meyer, Eric J. Morgan, David R. Munro, Shin-Ichiro Nakaoka, Yosuke Niwa, Kevin M. O'Brien, Are Olsen, Abdirahman M. Omar, Tsuneo Ono, Melf Paulsen, Denis Pierrot, Katie Pocock, Benjamin Poulter, Carter M. Powis, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M. Rosan, Jörg Schwinger, Roland Séférian, T. Luke Smallman, Stephen M. Smith, Reinel Sospedra-Alfonso, Qing Sun, Adrienne J. Sutton, Colm Sweeney, Shintaro Takao, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Hiroyuki Tsujino, Francesco Tubiello, Guido R. van der Werf, Erik van Ooijen, Rik Wanninkhof, Michio Watanabe, Cathy Wimart-Rousseau, Dongxu Yang, Xiaojuan Yang, Wenping Yuan, Xu Yue, Sönke Zaehle, Jiye Zeng, and Bo Zheng
Earth Syst. Sci. Data, 15, 5301–5369, https://doi.org/10.5194/essd-15-5301-2023, https://doi.org/10.5194/essd-15-5301-2023, 2023
Short summary
Short summary
The Global Carbon Budget 2023 describes the methodology, main results, and data sets used to quantify the anthropogenic emissions of carbon dioxide (CO2) and their partitioning among the atmosphere, land ecosystems, and the ocean over the historical period (1750–2023). These living datasets are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Matthew D. Eisaman, Sonja Geilert, Phil Renforth, Laura Bastianini, James Campbell, Andrew W. Dale, Spyros Foteinis, Patricia Grasse, Olivia Hawrot, Carolin R. Löscher, Greg H. Rau, and Jakob Rønning
State Planet, 2-oae2023, 3, https://doi.org/10.5194/sp-2-oae2023-3-2023, https://doi.org/10.5194/sp-2-oae2023-3-2023, 2023
Short summary
Short summary
Ocean-alkalinity-enhancement technologies refer to various methods and approaches aimed at increasing the alkalinity of seawater. This chapter explores technologies for increasing ocean alkalinity, including electrochemical-based approaches, ocean liming, accelerated weathering of limestone, hydrated carbonate addition, and coastal enhanced weathering, and suggests best practices in research and development.
Ulf Riebesell, Daniela Basso, Sonja Geilert, Andrew W. Dale, and Matthias Kreuzburg
State Planet, 2-oae2023, 6, https://doi.org/10.5194/sp-2-oae2023-6-2023, https://doi.org/10.5194/sp-2-oae2023-6-2023, 2023
Short summary
Short summary
Mesocosm experiments represent a highly valuable tool in determining the safe operating space of ocean alkalinity enhancement (OAE) applications. By combining realism and biological complexity with controllability and replication, they provide an ideal OAE test bed and a critical stepping stone towards field applications. Mesocosm approaches can also be helpful in testing the efficacy, efficiency and permanence of OAE applications.
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.
Sigrid van Grinsven and Carsten Schubert
Biogeosciences, 20, 4213–4220, https://doi.org/10.5194/bg-20-4213-2023, https://doi.org/10.5194/bg-20-4213-2023, 2023
Short summary
Short summary
Agriculture relies heavily on plastic mulch films, which may be transported to aquatic environments. We investigated the breakdown of soil-biodegradable agricultural mulch films in lake sediments. After 40 weeks, films were intact, and no significant CO2 or CH4 was produced from the biodegradable mulch films. We conclude that the mulch films we used have a low biodegradability in lake sediments. The sediment lacks the microbes needed to break down the biodegradable plastics that were used here.
Gesa Schulz, Tina Sanders, Yoana G. Voynova, Hermann W. Bange, and Kirstin Dähnke
Biogeosciences, 20, 3229–3247, https://doi.org/10.5194/bg-20-3229-2023, https://doi.org/10.5194/bg-20-3229-2023, 2023
Short summary
Short summary
Nitrous oxide (N2O) is an important greenhouse gas. However, N2O emissions from estuaries underlie significant uncertainties due to limited data availability and high spatiotemporal variability. We found the Elbe Estuary (Germany) to be a year-round source of N2O, with the highest emissions in winter along with high nitrogen loads. However, in spring and summer, N2O emissions did not decrease alongside lower nitrogen loads because organic matter fueled in situ N2O production along the estuary.
Georgia R. Grant, Jonny H. T. Williams, Sebastian Naeher, Osamu Seki, Erin L. McClymont, Molly O. Patterson, Alan M. Haywood, Erik Behrens, Masanobu Yamamoto, and Katelyn Johnson
Clim. Past, 19, 1359–1381, https://doi.org/10.5194/cp-19-1359-2023, https://doi.org/10.5194/cp-19-1359-2023, 2023
Short summary
Short summary
Regional warming will differ from global warming, and climate models perform poorly in the Southern Ocean. We reconstruct sea surface temperatures in the south-west Pacific during the mid-Pliocene, a time 3 million years ago that represents the long-term outcomes of 3 °C warming, which is expected for the future. Comparing these results to climate model simulations, we show that the south-west Pacific region will warm by 1 °C above the global average if atmospheric CO2 remains above 350 ppm.
Paul D. Zander, Stefanie B. Wirth, Adrian Gilli, Sandro Peduzzi, and Martin Grosjean
Biogeosciences, 20, 2221–2235, https://doi.org/10.5194/bg-20-2221-2023, https://doi.org/10.5194/bg-20-2221-2023, 2023
Short summary
Short summary
This study shows, for the first time, that hyperspectral imaging can detect bacteriochlorophyll pigments produced by green sulfur bacteria in sediment cores. We tested our method on cores from Lake Cadagno, Switzerland, and were able to reconstruct high-resolution variations in the abundance of green and purple sulfur bacteria over the past 12 700 years. Climate conditions, flood events, and land use had major impacts on the lake’s biogeochemical conditions over short and long timescales.
Guanlin Li, Damian L. Arévalo-Martínez, Riel Carlo O. Ingeniero, and Hermann W. Bange
EGUsphere, https://doi.org/10.5194/egusphere-2023-771, https://doi.org/10.5194/egusphere-2023-771, 2023
Preprint archived
Short summary
Short summary
Dissolved carbon monoxide (CO) surface concentrations were first measured at 14 stations in the Ria Formosa Lagoon system in May 2021. Ria Formosa was a source of atmospheric CO. Microbial consumption accounted for 83 % of the CO production. The results of a 48-hour irradiation experiment with aquaculture effluent water indicated that aquaculture facilities in the Ria Formosa Lagoon seem to be a negligible source of atmospheric CO.
Hanna I. Campen, Damian L. Arévalo-Martínez, and Hermann W. Bange
Biogeosciences, 20, 1371–1379, https://doi.org/10.5194/bg-20-1371-2023, https://doi.org/10.5194/bg-20-1371-2023, 2023
Short summary
Short summary
Carbon monoxide (CO) is a climate-relevant trace gas emitted from the ocean. However, oceanic CO cycling is understudied. Results from incubation experiments conducted in the Fram Strait (Arctic Ocean) indicated that (i) pH did not affect CO cycling and (ii) enhanced CO production and consumption were positively correlated with coloured dissolved organic matter and nitrate concentrations. This suggests microbial CO uptake to be the driving factor for CO cycling in the Arctic Ocean.
R. Scott Winton, Silvia López-Casas, Daniel Valencia-Rodríguez, Camilo Bernal-Forero, Juliana Delgado, Bernhard Wehrli, and Luz Jiménez-Segura
Hydrol. Earth Syst. Sci., 27, 1493–1505, https://doi.org/10.5194/hess-27-1493-2023, https://doi.org/10.5194/hess-27-1493-2023, 2023
Short summary
Short summary
Dams are an important and rapidly growing means of energy generation in the Tropical Andes of South America. To assess the impacts of dams in the region, we assessed differences in the upstream and downstream water quality of all hydropower dams in Colombia. We found evidence of substantial dam-induced changes in water temperature, dissolved oxygen concentration and suspended sediments. Dam-induced changes in Colombian waters violate regulations and are likely impacting aquatic life.
Damian L. Arévalo-Martínez, Amir Haroon, Hermann W. Bange, Ercan Erkul, Marion Jegen, Nils Moosdorf, Jens Schneider von Deimling, Christian Berndt, Michael Ernst Böttcher, Jasper Hoffmann, Volker Liebetrau, Ulf Mallast, Gudrun Massmann, Aaron Micallef, Holly A. Michael, Hendrik Paasche, Wolfgang Rabbel, Isaac Santos, Jan Scholten, Katrin Schwalenberg, Beata Szymczycha, Ariel T. Thomas, Joonas J. Virtasalo, Hannelore Waska, and Bradley A. Weymer
Biogeosciences, 20, 647–662, https://doi.org/10.5194/bg-20-647-2023, https://doi.org/10.5194/bg-20-647-2023, 2023
Short summary
Short summary
Groundwater flows at the land–ocean transition and the extent of freshened groundwater below the seafloor are increasingly relevant in marine sciences, both because they are a highly uncertain term of biogeochemical budgets and due to the emerging interest in the latter as a resource. Here, we discuss our perspectives on future research directions to better understand land–ocean connectivity through groundwater and its potential responses to natural and human-induced environmental changes.
Daniel L. Pönisch, Anne Breznikar, Cordula N. Gutekunst, Gerald Jurasinski, Maren Voss, and Gregor Rehder
Biogeosciences, 20, 295–323, https://doi.org/10.5194/bg-20-295-2023, https://doi.org/10.5194/bg-20-295-2023, 2023
Short summary
Short summary
Peatland rewetting is known to reduce dissolved nutrients and greenhouse gases; however, short-term nutrient leaching and high CH4 emissions shortly after rewetting are likely to occur. We investigated the rewetting of a coastal peatland with brackish water and its effects on nutrient release and greenhouse gas fluxes. Nutrient concentrations were higher in the peatland than in the adjacent bay, leading to an export. CH4 emissions did not increase, which is in contrast to freshwater rewetting.
Pierre Henry, M. Sinan Özeren, Nurettin Yakupoğlu, Ziyadin Çakir, Emmanuel de Saint-Léger, Olivier Desprez de Gésincourt, Anders Tengberg, Cristele Chevalier, Christos Papoutsellis, Nazmi Postacıoğlu, Uğur Dogan, Hayrullah Karabulut, Gülsen Uçarkuş, and M. Namık Çağatay
Nat. Hazards Earth Syst. Sci., 22, 3939–3956, https://doi.org/10.5194/nhess-22-3939-2022, https://doi.org/10.5194/nhess-22-3939-2022, 2022
Short summary
Short summary
Seafloor instruments at the bottom of the Sea of Marmara recorded disturbances caused by earthquakes, addressing the minimum magnitude that may be recorded in the sediment. A magnitude 4.7 earthquake caused turbidity but little current. A magnitude 5.8 earthquake caused a mudflow and strong currents that spread sediment on the seafloor over several kilometers. However, most known earthquake deposits in the Sea of Marmara spread over larger zones and should correspond to larger earthquakes.
Thomas Neumann, Hagen Radtke, Bronwyn Cahill, Martin Schmidt, and Gregor Rehder
Geosci. Model Dev., 15, 8473–8540, https://doi.org/10.5194/gmd-15-8473-2022, https://doi.org/10.5194/gmd-15-8473-2022, 2022
Short summary
Short summary
Marine ecosystem models are usually constrained by the elements nitrogen and phosphorus and consider carbon in organic matter in a fixed ratio. Recent observations show a substantial deviation from the simulated carbon cycle variables. In this study, we present a marine ecosystem model for the Baltic Sea which allows for a flexible uptake ratio for carbon, nitrogen, and phosphorus. With this extension, the model reflects much more reasonable variables of the marine carbon cycle.
Wout Krijgsman, Iuliana Vasiliev, Anouk Beniest, Timothy Lyons, Johanna Lofi, Gabor Tari, Caroline P. Slomp, Namik Cagatay, Maria Triantaphyllou, Rachel Flecker, Dan Palcu, Cecilia McHugh, Helge Arz, Pierre Henry, Karen Lloyd, Gunay Cifci, Özgür Sipahioglu, Dimitris Sakellariou, and the BlackGate workshop participants
Sci. Dril., 31, 93–110, https://doi.org/10.5194/sd-31-93-2022, https://doi.org/10.5194/sd-31-93-2022, 2022
Short summary
Short summary
BlackGate seeks to MSP drill a transect to study the impact of dramatic hydrologic change in Mediterranean–Black Sea connectivity by recovering the Messinian to Holocene (~ 7 Myr) sedimentary sequence in the North Aegean, Marmara, and Black seas. These archives will reveal hydrographic, biotic, and climatic transitions studied by a broad scientific community spanning the stratigraphic, tectonic, biogeochemical, and microbiological evolution of Earth’s most recent saline and anoxic giant.
Sonja Gindorf, Hermann W. Bange, Dennis Booge, and Annette Kock
Biogeosciences, 19, 4993–5006, https://doi.org/10.5194/bg-19-4993-2022, https://doi.org/10.5194/bg-19-4993-2022, 2022
Short summary
Short summary
Methane is a climate-relevant greenhouse gas which is emitted to the atmosphere from coastal areas such as the Baltic Sea. We measured the methane concentration in the water column of the western Kiel Bight. Methane concentrations were higher in September than in June. We found no relationship between the 2018 European heatwave and methane concentrations. Our results show that the methane distribution in the water column is strongly affected by temporal and spatial variabilities.
Christopher J. Hollis, Sebastian Naeher, Christopher D. Clowes, B. David A. Naafs, Richard D. Pancost, Kyle W. R. Taylor, Jenny Dahl, Xun Li, G. Todd Ventura, and Richard Sykes
Clim. Past, 18, 1295–1320, https://doi.org/10.5194/cp-18-1295-2022, https://doi.org/10.5194/cp-18-1295-2022, 2022
Short summary
Short summary
Previous studies of Paleogene greenhouse climates identified short-lived global warming events, termed hyperthermals, that provide insights into global warming scenarios. Within the same time period, we have identified a short-lived cooling event in the late Paleocene, which we term a hypothermal, that has potential to provide novel insights into the feedback mechanisms at work in a greenhouse climate.
Pierre Friedlingstein, Matthew W. Jones, Michael O'Sullivan, Robbie M. Andrew, Dorothee C. E. Bakker, Judith Hauck, Corinne Le Quéré, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Rob B. Jackson, Simone R. Alin, Peter Anthoni, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Laurent Bopp, Thi Tuyet Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Kim I. Currie, Bertrand Decharme, Laique M. Djeutchouang, Xinyu Dou, Wiley Evans, Richard A. Feely, Liang Feng, Thomas Gasser, Dennis Gilfillan, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Ingrid T. Luijkx, Atul Jain, Steve D. Jones, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Sebastian Lienert, Junjie Liu, Gregg Marland, Patrick C. McGuire, Joe R. Melton, David R. Munro, Julia E. M. S. Nabel, Shin-Ichiro Nakaoka, Yosuke Niwa, Tsuneo Ono, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M. Rosan, Jörg Schwinger, Clemens Schwingshackl, Roland Séférian, Adrienne J. Sutton, Colm Sweeney, Toste Tanhua, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco Tubiello, Guido R. van der Werf, Nicolas Vuichard, Chisato Wada, Rik Wanninkhof, Andrew J. Watson, David Willis, Andrew J. Wiltshire, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, and Jiye Zeng
Earth Syst. Sci. Data, 14, 1917–2005, https://doi.org/10.5194/essd-14-1917-2022, https://doi.org/10.5194/essd-14-1917-2022, 2022
Short summary
Short summary
The Global Carbon Budget 2021 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Karol Kuliński, Gregor Rehder, Eero Asmala, Alena Bartosova, Jacob Carstensen, Bo Gustafsson, Per O. J. Hall, Christoph Humborg, Tom Jilbert, Klaus Jürgens, H. E. Markus Meier, Bärbel Müller-Karulis, Michael Naumann, Jørgen E. Olesen, Oleg Savchuk, Andreas Schramm, Caroline P. Slomp, Mikhail Sofiev, Anna Sobek, Beata Szymczycha, and Emma Undeman
Earth Syst. Dynam., 13, 633–685, https://doi.org/10.5194/esd-13-633-2022, https://doi.org/10.5194/esd-13-633-2022, 2022
Short summary
Short summary
The paper covers the aspects related to changes in carbon, nitrogen, and phosphorus (C, N, P) external loads; their transformations in the coastal zone; changes in organic matter production (eutrophication) and remineralization (oxygen availability); and the role of sediments in burial and turnover of C, N, and P. Furthermore, this paper also focuses on changes in the marine CO2 system, the structure of the microbial community, and the role of contaminants for biogeochemical processes.
Yanan Zhao, Dennis Booge, Christa A. Marandino, Cathleen Schlundt, Astrid Bracher, Elliot L. Atlas, Jonathan Williams, and Hermann W. Bange
Biogeosciences, 19, 701–714, https://doi.org/10.5194/bg-19-701-2022, https://doi.org/10.5194/bg-19-701-2022, 2022
Short summary
Short summary
We present here, for the first time, simultaneously measured dimethylsulfide (DMS) seawater concentrations and DMS atmospheric mole fractions from the Peruvian upwelling region during two cruises in December 2012 and October 2015. Our results indicate low oceanic DMS concentrations and atmospheric DMS molar fractions in surface waters and the atmosphere, respectively. In addition, the Peruvian upwelling region was identified as an insignificant source of DMS emissions during both periods.
Wangwang Ye, Hermann W. Bange, Damian L. Arévalo-Martínez, Hailun He, Yuhong Li, Jianwen Wen, Jiexia Zhang, Jian Liu, Man Wu, and Liyang Zhan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-334, https://doi.org/10.5194/bg-2021-334, 2022
Manuscript not accepted for further review
Short summary
Short summary
CH4 is the second important greenhouse gas after CO2. We show that CH4 consumption and sea-ice melting influence the CH4 distribution in the Ross Sea (Southern Ocean), causing undersaturation and net uptake of CH4 during summertime. This study confirms the capability of surface water in the high-latitude Southern Ocean regions to take up atmospheric CH4 which, in turn, will help to improve predictions of how CH4 release/uptake from the ocean will develop when sea-ice retreats in the future.
Martti Honkanen, Jens Daniel Müller, Jukka Seppälä, Gregor Rehder, Sami Kielosto, Pasi Ylöstalo, Timo Mäkelä, Juha Hatakka, and Lauri Laakso
Ocean Sci., 17, 1657–1675, https://doi.org/10.5194/os-17-1657-2021, https://doi.org/10.5194/os-17-1657-2021, 2021
Short summary
Short summary
The exchange of carbon dioxide (CO2) between the sea and the atmosphere is regulated by the gradient of CO2 partial pressure (pCO2) between the sea and the air. The daily variation of the seawater pCO2 recorded at the fixed station Utö in the Baltic Sea was found to be mainly biologically driven. Calculation of the annual net exchange of CO2 between the sea and atmosphere based on daily measurements of pCO2 carried out using the same sampling time every day could introduce a bias of up to 12 %.
Jens Daniel Müller, Bernd Schneider, Ulf Gräwe, Peer Fietzek, Marcus Bo Wallin, Anna Rutgersson, Norbert Wasmund, Siegfried Krüger, and Gregor Rehder
Biogeosciences, 18, 4889–4917, https://doi.org/10.5194/bg-18-4889-2021, https://doi.org/10.5194/bg-18-4889-2021, 2021
Short summary
Short summary
Based on profiling pCO2 measurements from a field campaign, we quantify the biomass production of a cyanobacteria bloom in the Baltic Sea, the export of which would foster deep water deoxygenation. We further demonstrate how this biomass production can be accurately reconstructed from long-term surface measurements made on cargo vessels in combination with modelled temperature profiles. This approach enables a better understanding of a severe concern for the Baltic’s good environmental status.
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.
Anna Canning, Bernhard Wehrli, and Arne Körtzinger
Biogeosciences, 18, 3961–3979, https://doi.org/10.5194/bg-18-3961-2021, https://doi.org/10.5194/bg-18-3961-2021, 2021
Short summary
Short summary
Inland waters are usually not well restrained in terms of greenhouse gas measurements. One of these regions is the Danube Delta, Romania. Therefore, we measured continuously with sensors to collect high-resolution data for CH4 and O2 throughout the Delta. We found significant variation for all concentrations over the day and night and between regions, as well as large spatial variation throughout all regions, with large CH4 concentrations flowing in from the reed beds to the lakes.
Sigrid van Grinsven, Kirsten Oswald, Bernhard Wehrli, Corinne Jegge, Jakob Zopfi, Moritz F. Lehmann, and Carsten J. Schubert
Biogeosciences, 18, 3087–3101, https://doi.org/10.5194/bg-18-3087-2021, https://doi.org/10.5194/bg-18-3087-2021, 2021
Short summary
Short summary
Lake Lovojärvi is a nutrient-rich lake with high amounts of methane at the bottom, but little near the top. Methane comes from the sediment and rises up through the water but is consumed by microorganisms along the way. They use oxygen if available, but in deeper water layers, no oxygen was present. There, nitrite, iron and humic substances were used, besides a collaboration between photosynthetic organisms and methane consumers, in which the first produced oxygen for the latter.
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.
Luca Possenti, Ingunn Skjelvan, Dariia Atamanchuk, Anders Tengberg, Matthew P. Humphreys, Socratis Loucaides, Liam Fernand, and Jan Kaiser
Ocean Sci., 17, 593–614, https://doi.org/10.5194/os-17-593-2021, https://doi.org/10.5194/os-17-593-2021, 2021
Short summary
Short summary
A Seaglider was deployed for 8 months in the Norwegian Sea mounting an oxygen and, for the first time, a CO2 optode and a chlorophyll fluorescence sensor. The oxygen and CO2 data were used to assess the spatial and temporal variability and calculate the net community production, N(O2) and N(CT). The dataset was used to calculate net community production from inventory changes, air–sea flux, diapycnal mixing and entrainment.
Erik Jacobs, Henry C. Bittig, Ulf Gräwe, Carolyn A. Graves, Michael Glockzin, Jens D. Müller, Bernd Schneider, and Gregor Rehder
Biogeosciences, 18, 2679–2709, https://doi.org/10.5194/bg-18-2679-2021, https://doi.org/10.5194/bg-18-2679-2021, 2021
Short summary
Short summary
We use a unique data set of 8 years of continuous carbon dioxide (CO2) and methane (CH4) surface water measurements from a commercial ferry to study upwelling in the Baltic Sea. Its seasonality and regional and interannual variability are examined. Strong upwelling events drastically increase local surface CO2 and CH4 levels and are mostly detected in late summer after long periods of impaired mixing. We introduce an extrapolation method to estimate regional upwelling-induced trace gas fluxes.
Trystan Sanders, Jörn Thomsen, Jens Daniel Müller, Gregor Rehder, and Frank Melzner
Biogeosciences, 18, 2573–2590, https://doi.org/10.5194/bg-18-2573-2021, https://doi.org/10.5194/bg-18-2573-2021, 2021
Short summary
Short summary
The Baltic Sea is expected to experience a rapid drop in salinity and increases in acidity and warming in the next century. Calcifying mussels dominate Baltic Sea seafloor ecosystems yet are sensitive to changes in seawater chemistry. We combine laboratory experiments and a field study and show that a lack of calcium causes extremely slow growth rates in mussels at low salinities. Subsequently, climate change in the Baltic may have drastic ramifications for Baltic seafloor ecosystems.
Gerd Krahmann, Damian L. Arévalo-Martínez, Andrew W. Dale, Marcus Dengler, Anja Engel, Nicolaas Glock, Patricia Grasse, Johannes Hahn, Helena Hauss, Mark Hopwood, Rainer Kiko, Alexandra Loginova, Carolin R. Löscher, Marie Maßmig, Alexandra-Sophie Roy, Renato Salvatteci, Stefan Sommer, Toste Tanhua, and Hela Mehrtens
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2020-308, https://doi.org/10.5194/essd-2020-308, 2021
Preprint withdrawn
Short summary
Short summary
The project "Climate-Biogeochemistry Interactions in the Tropical Ocean" (SFB 754) was a multidisciplinary research project active from 2008 to 2019 aimed at a better understanding of the coupling between the tropical climate and ocean circulation and the ocean's oxygen and nutrient balance. On 34 research cruises, mainly in the Southeast Tropical Pacific and the Northeast Tropical Atlantic, 1071 physical, chemical and biological data sets were collected.
Yanan Zhao, Cathleen Schlundt, Dennis Booge, and Hermann W. Bange
Biogeosciences, 18, 2161–2179, https://doi.org/10.5194/bg-18-2161-2021, https://doi.org/10.5194/bg-18-2161-2021, 2021
Short summary
Short summary
We present a unique and comprehensive time-series study of biogenic sulfur compounds in the southwestern Baltic Sea, from 2009 to 2018. Dimethyl sulfide is one of the key players regulating global climate change, as well as dimethylsulfoniopropionate and dimethyl sulfoxide. Their decadal trends did not follow increasing temperature but followed some algae group abundances at the Boknis Eck Time Series Station.
Marie-Sophie Maier, Cristian R. Teodoru, and Bernhard Wehrli
Biogeosciences, 18, 1417–1437, https://doi.org/10.5194/bg-18-1417-2021, https://doi.org/10.5194/bg-18-1417-2021, 2021
Short summary
Short summary
Based on a 2-year monitoring study, we found that the freshwater system of the Danube Delta, Romania, releases carbon dioxide and methane to the atmosphere. The amount of carbon released depends on the freshwater feature (river branches, channels and lakes), season and hydrologic condition, affecting the exchange with the wetland. Spatial upscaling should therefore consider these factors. Furthermore, the Danube Delta increases the amount of carbon reaching the Black Sea via the Danube River.
Anna Rose Canning, Peer Fietzek, Gregor Rehder, and Arne Körtzinger
Biogeosciences, 18, 1351–1373, https://doi.org/10.5194/bg-18-1351-2021, https://doi.org/10.5194/bg-18-1351-2021, 2021
Short summary
Short summary
The paper describes a novel, fully autonomous, multi-gas flow-through set-up for multiple gases that combines established, high-quality oceanographic sensors in a small and robust system designed for use across all salinities and all types of platforms. We describe the system and its performance in all relevant detail, including the corrections which improve the accuracy of these sensors, and illustrate how simultaneous multi-gas set-ups can provide an extremely high spatiotemporal resolution.
Meike Becker, Are Olsen, Peter Landschützer, Abdirhaman Omar, Gregor Rehder, Christian Rödenbeck, and Ingunn Skjelvan
Biogeosciences, 18, 1127–1147, https://doi.org/10.5194/bg-18-1127-2021, https://doi.org/10.5194/bg-18-1127-2021, 2021
Short summary
Short summary
We developed a simple method to refine existing open-ocean maps towards different coastal seas. Using a multi-linear regression, we produced monthly maps of surface ocean fCO2 in the northern European coastal seas (the North Sea, the Baltic Sea, the Norwegian Coast and the Barents Sea) covering a time period from 1998 to 2016. Based on this fCO2 map, we calculate trends in surface ocean fCO2, pH and the air–sea gas exchange.
Samuel T. Wilson, Alia N. Al-Haj, Annie Bourbonnais, Claudia Frey, Robinson W. Fulweiler, John D. Kessler, Hannah K. Marchant, Jana Milucka, Nicholas E. Ray, Parvadha Suntharalingam, Brett F. Thornton, Robert C. Upstill-Goddard, Thomas S. Weber, Damian L. Arévalo-Martínez, Hermann W. Bange, Heather M. Benway, Daniele Bianchi, Alberto V. Borges, Bonnie X. Chang, Patrick M. Crill, Daniela A. del Valle, Laura Farías, Samantha B. Joye, Annette Kock, Jabrane Labidi, Cara C. Manning, John W. Pohlman, Gregor Rehder, Katy J. Sparrow, Philippe D. Tortell, Tina Treude, David L. Valentine, Bess B. Ward, Simon Yang, and Leonid N. Yurganov
Biogeosciences, 17, 5809–5828, https://doi.org/10.5194/bg-17-5809-2020, https://doi.org/10.5194/bg-17-5809-2020, 2020
Short summary
Short summary
The oceans are a net source of the major greenhouse gases; however there has been little coordination of oceanic methane and nitrous oxide measurements. The scientific community has recently embarked on a series of capacity-building exercises to improve the interoperability of dissolved methane and nitrous oxide measurements. This paper derives from a workshop which discussed the challenges and opportunities for oceanic methane and nitrous oxide research in the near future.
Jan Lüdke, Marcus Dengler, Stefan Sommer, David Clemens, Sören Thomsen, Gerd Krahmann, Andrew W. Dale, Eric P. Achterberg, and Martin Visbeck
Ocean Sci., 16, 1347–1366, https://doi.org/10.5194/os-16-1347-2020, https://doi.org/10.5194/os-16-1347-2020, 2020
Short summary
Short summary
We analyse the intraseasonal variability of the alongshore circulation off Peru in early 2017, this circulation is very important for the supply of nutrients to the upwelling regime. The causes of this variability and its impact on the biogeochemistry are investigated. The poleward flow is strengthened during the observed time period, likely by a downwelling coastal trapped wave. The stronger current causes an increase in nitrate and reduces the deficit of fixed nitrogen relative to phosphorus.
Alexandra N. Loginova, Andrew W. Dale, Frédéric A. C. Le Moigne, Sören Thomsen, Stefan Sommer, David Clemens, Klaus Wallmann, and Anja Engel
Biogeosciences, 17, 4663–4679, https://doi.org/10.5194/bg-17-4663-2020, https://doi.org/10.5194/bg-17-4663-2020, 2020
Short summary
Short summary
We measured dissolved organic carbon (DOC), nitrogen (DON) and matter (DOM) optical properties in pore waters and near-bottom waters of the eastern tropical South Pacific off Peru. The difference between diffusion-driven and net fluxes of DOC and DON and qualitative changes in DOM optical properties suggested active microbial utilisation of the released DOM at the sediment–water interface. Our results suggest that the sediment release of DOM contributes to microbial processes in the area.
Magdalena J. Mayr, Matthias Zimmermann, Jason Dey, Bernhard Wehrli, and Helmut Bürgmann
Biogeosciences, 17, 4247–4259, https://doi.org/10.5194/bg-17-4247-2020, https://doi.org/10.5194/bg-17-4247-2020, 2020
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.
Xiao Ma, Mingshuang Sun, Sinikka T. Lennartz, and Hermann W. Bange
Biogeosciences, 17, 3427–3438, https://doi.org/10.5194/bg-17-3427-2020, https://doi.org/10.5194/bg-17-3427-2020, 2020
Short summary
Short summary
Monthly measurements of dissolved methane (CH4), a potent greenhouse gas, were conducted at Boknis Eck (BE), a time-series station in the southwestern Baltic Sea, from June 2006. In general CH4 concentrations increased with depth. High concentrations in the upper layer were linked to saline water inflow. Eckernförde Bay emitted CH4 to the atmosphere throughout the monitoring period. No significant trend was detected in CH4 concentrations or emissions during 2006–2017.
Massimiliano Molari, Felix Janssen, Tobias R. Vonnahme, Frank Wenzhöfer, and Antje Boetius
Biogeosciences, 17, 3203–3222, https://doi.org/10.5194/bg-17-3203-2020, https://doi.org/10.5194/bg-17-3203-2020, 2020
Short summary
Short summary
Industrial-scale mining of deep-sea polymetallic nodules will remove nodules in large areas of the sea floor. We describe community composition of microbes associated with nodules of the Peru Basin. Our results show that nodules provide a unique ecological niche, playing an important role in shaping the diversity of the benthic deep-sea microbiome and potentially in element fluxes. We believe that our findings are highly relevant to expanding our knowledge of the impact associated with mining.
Benedikt Ehrenfels, Maciej Bartosiewicz, Athanasio S. Mbonde, Kathrin B. L. Baumann, Christian Dinkel, Julian Junker, Tumaini Kamulali, Ismael A. Kimirei, Daniel Odermatt, Francesco Pomati, Emmanuel A. Sweke, and Bernhard Wehrli
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-214, https://doi.org/10.5194/bg-2020-214, 2020
Revised manuscript not accepted
Short summary
Short summary
Cyanobacterial blooms are a widespread phenomenon, but their formation is poorly understood in nutrient-poor water bodies. During two cruises we collected physical, nutrient, pigment and phytoplankton data to study nitrogen fixing cyanobacteria (diazotrophs) in Lake Tanganyika, Africa. We found that, due to their capability of fixing gaseous nitrogen, diazotrophs thrive when the supply of dissolved inorganic nitrogen to the sun-lit surface waters is low, but phosphorous is still available.
Zeynep Erdem, Joachim Schönfeld, Anthony E. Rathburn, Maria-Elena Pérez, Jorge Cardich, and Nicolaas Glock
Biogeosciences, 17, 3165–3182, https://doi.org/10.5194/bg-17-3165-2020, https://doi.org/10.5194/bg-17-3165-2020, 2020
Short summary
Short summary
Recent observations from today’s oceans revealed that oxygen concentrations are decreasing, and oxygen minimum zones are expanding together with current climate change. With the aim of understanding past climatic events and their relationship with oxygen content, we looked at the fossils, called benthic foraminifera, preserved in the sediment archives from the Peruvian margin and quantified the bottom-water oxygen content for the last 22 000 years.
Alexander Bratek, Justus E. E. van
Beusekom, Andreas Neumann, Tina Sanders, Jana Friedrich, Kay-Christian Emeis, and Kirstin Dähnke
Biogeosciences, 17, 2839–2851, https://doi.org/10.5194/bg-17-2839-2020, https://doi.org/10.5194/bg-17-2839-2020, 2020
Short summary
Short summary
The following paper highlights the importance of benthic N-transformation rates in different sediment types in the southern North Sea as a source of fixed nitrogen for primary producers and also as a sink of fixed nitrogen. Sedimentary fluxes of dissolved inorganic nitrogen support ∼7 to 59 % of the average annual primary production. Semi-permeable and permeable sediments contribute ∼68 % of the total benthic N2 production rates, counteracting eutrophication in the southern North Sea.
Laura Haffert, Matthias Haeckel, Henko de Stigter, and Felix Janssen
Biogeosciences, 17, 2767–2789, https://doi.org/10.5194/bg-17-2767-2020, https://doi.org/10.5194/bg-17-2767-2020, 2020
Short summary
Short summary
Deep-sea mining for polymetallic nodules is expected to have severe environmental impacts. Through prognostic modelling, this study aims to provide a holistic assessment of the biogeochemical recovery after a disturbance event. It was found that the recovery strongly depends on the impact type; e.g. complete removal of the surface sediment reduces seafloor nutrient fluxes over centuries.
Marcel Ricker and Emil V. Stanev
Ocean Sci., 16, 637–655, https://doi.org/10.5194/os-16-637-2020, https://doi.org/10.5194/os-16-637-2020, 2020
Short summary
Short summary
The dynamics of the European northwest shelf are analysed using both classical Eulerian and Lagrangian data from simulated particles. Focussing on the latter, a quantity named
normalised cumulative particle densitymeasures particle accumulation. Yearly averages reveal no surface accumulation areas in the deep ocean and elongated patterns on the shelf mainly along fronts. Sensitivity experiments show the influence of tides and wind, unveiling important vertical dynamics in coastal areas.
Claudia Frey, Hermann W. Bange, Eric P. Achterberg, Amal Jayakumar, Carolin R. Löscher, Damian L. Arévalo-Martínez, Elizabeth León-Palmero, Mingshuang Sun, Xin Sun, Ruifang C. Xie, Sergey Oleynik, and Bess B. Ward
Biogeosciences, 17, 2263–2287, https://doi.org/10.5194/bg-17-2263-2020, https://doi.org/10.5194/bg-17-2263-2020, 2020
Short summary
Short summary
The production of N2O via nitrification and denitrification associated with low-O2 waters is a major source of oceanic N2O. We investigated the regulation and dynamics of these processes with respect to O2 and organic matter inputs. The transcription of the key nitrification gene amoA rapidly responded to changes in O2 and strongly correlated with N2O production rates. N2O production by denitrification was clearly stimulated by organic carbon, implying that its supply controls N2O production.
Carolin R. Löscher, Wiebke Mohr, Hermann W. Bange, and Donald E. Canfield
Biogeosciences, 17, 851–864, https://doi.org/10.5194/bg-17-851-2020, https://doi.org/10.5194/bg-17-851-2020, 2020
Short summary
Short summary
Oxygen minimum zones (OMZs) are ocean areas severely depleted in oxygen as a result of physical, chemical, and biological processes. Biologically, organic material is produced in the sea surface and exported to deeper waters, where it respires. In the Bay of Bengal (BoB), an OMZ is present, but there are traces of oxygen left. Our study now suggests that this is because one key process, nitrogen fixation, is absent in the BoB, thus preventing primary production and consecutive respiration.
Ye Tian, Gui-Peng Yang, Chun-Ying Liu, Pei-Feng Li, Hong-Tao Chen, and Hermann W. Bange
Ocean Sci., 16, 135–148, https://doi.org/10.5194/os-16-135-2020, https://doi.org/10.5194/os-16-135-2020, 2020
Short summary
Short summary
Nitric oxide (NO) could be produced by nitrite photolysis; the rates from dissolved nitrite in artificial seawater showed increasing trends with decreasing pH, increasing temperatures, and increasing salinity. However, NO photoproduction from the natural seawater samples did not show correlations with pH, water temperature, salinity, or dissolved nitrite concentrations in the western tropical North Pacific Ocean (WNTP). And there were other NO loss processes in the surface layer of WNTP.
Thomas Holding, Ian G. Ashton, Jamie D. Shutler, Peter E. Land, Philip D. Nightingale, Andrew P. Rees, Ian Brown, Jean-Francois Piolle, Annette Kock, Hermann W. Bange, David K. Woolf, Lonneke Goddijn-Murphy, Ryan Pereira, Frederic Paul, Fanny Girard-Ardhuin, Bertrand Chapron, Gregor Rehder, Fabrice Ardhuin, and Craig J. Donlon
Ocean Sci., 15, 1707–1728, https://doi.org/10.5194/os-15-1707-2019, https://doi.org/10.5194/os-15-1707-2019, 2019
Short summary
Short summary
FluxEngine is an open-source software toolbox designed to allow for the easy and accurate calculation of air–sea gas fluxes. This article describes new functionality and capabilities, which include the ability to calculate fluxes for nitrous oxide and methane, optimisation for running FluxEngine on a stand-alone desktop computer, and extensive new features to support the in situ measurement community. Four research case studies are used to demonstrate these new features.
Pierre Friedlingstein, Matthew W. Jones, Michael O'Sullivan, Robbie M. Andrew, Judith Hauck, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Corinne Le Quéré, Dorothee C. E. Bakker, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Peter Anthoni, Leticia Barbero, Ana Bastos, Vladislav Bastrikov, Meike Becker, Laurent Bopp, Erik Buitenhuis, Naveen Chandra, Frédéric Chevallier, Louise P. Chini, Kim I. Currie, Richard A. Feely, Marion Gehlen, Dennis Gilfillan, Thanos Gkritzalis, Daniel S. Goll, Nicolas Gruber, Sören Gutekunst, Ian Harris, Vanessa Haverd, Richard A. Houghton, George Hurtt, Tatiana Ilyina, Atul K. Jain, Emilie Joetzjer, Jed O. Kaplan, Etsushi Kato, Kees Klein Goldewijk, Jan Ivar Korsbakken, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Andrew Lenton, Sebastian Lienert, Danica Lombardozzi, Gregg Marland, Patrick C. McGuire, Joe R. Melton, Nicolas Metzl, David R. Munro, Julia E. M. S. Nabel, Shin-Ichiro Nakaoka, Craig Neill, Abdirahman M. Omar, Tsuneo Ono, Anna Peregon, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Roland Séférian, Jörg Schwinger, Naomi Smith, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco N. Tubiello, Guido R. van der Werf, Andrew J. Wiltshire, and Sönke Zaehle
Earth Syst. Sci. Data, 11, 1783–1838, https://doi.org/10.5194/essd-11-1783-2019, https://doi.org/10.5194/essd-11-1783-2019, 2019
Short summary
Short summary
The Global Carbon Budget 2019 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Ye Tian, Chao Xue, Chun-Ying Liu, Gui-Peng Yang, Pei-Feng Li, Wei-Hua Feng, and Hermann W. Bange
Biogeosciences, 16, 4485–4496, https://doi.org/10.5194/bg-16-4485-2019, https://doi.org/10.5194/bg-16-4485-2019, 2019
Short summary
Short summary
Nitric oxide (NO) seems to be widespread, with different functions in the marine ecosystem, but we know little about it. Concentrations of NO were in a range from below the limit of detection to 616 pmol L−1 at the surface and 482 pmol L−1 at the bottom of the Bohai and Yellow seas. The study region was a source of atmospheric NO. Net NO sea-to-air fluxes were much lower than NO photoproduction rates, implying that the NO produced in the mixed layer was rapidly consumed before entering the air.
Hermann W. Bange, Chun Hock Sim, Daniel Bastian, Jennifer Kallert, Annette Kock, Aazani Mujahid, and Moritz Müller
Biogeosciences, 16, 4321–4335, https://doi.org/10.5194/bg-16-4321-2019, https://doi.org/10.5194/bg-16-4321-2019, 2019
Short summary
Short summary
Nitrous oxide (N2O) and methane (CH4) are atmospheric trace gases which play important roles in the climate and atmospheric chemistry of the Earth. However, little is known about their emissions from rivers and estuaries. To this end, concentrations of N2O and CH4 were measured during a seasonal study in six rivers and estuaries in northwestern Borneo. The concentrations of both gases were mainly driven by rainfall. The rivers and estuaries were an overall net source of atmospheric N2O and CH4.
Xiao Ma, Sinikka T. Lennartz, and Hermann W. Bange
Biogeosciences, 16, 4097–4111, https://doi.org/10.5194/bg-16-4097-2019, https://doi.org/10.5194/bg-16-4097-2019, 2019
Short summary
Short summary
Monthly measurements of nitrous oxide (N2O), a potent greenhouse gas and ozone depletion agent, were conducted at Boknis Eck (BE), a time series station in the southwestern Baltic Sea, since July 2005. Low N2O concentrations were observed in autumn and high in winter and early spring. Dissolved nutrients and oxygen played important roles in N2O distribution. Although we did not observe a significant N2O trend during 2005–2017, a decrease in N2O concentration and emission seems likely in future.
Eric J. Morgan, Jost V. Lavric, Damian L. Arévalo-Martínez, Hermann W. Bange, Tobias Steinhoff, Thomas Seifert, and Martin Heimann
Biogeosciences, 16, 4065–4084, https://doi.org/10.5194/bg-16-4065-2019, https://doi.org/10.5194/bg-16-4065-2019, 2019
Short summary
Short summary
Taking a 2-year atmospheric record of atmospheric oxygen and the greenhouse gases N2O, CO2, and CH4, made at a coastal site in the Namib Desert, we estimated the fluxes of these gases from upwelling events in the northern Benguela Current region. We compared these results with flux measurements made on a research vessel in the study area at the same time and found that the two approaches agreed well. The study region was a source of N2O, CO2, and CH4 to the atmosphere during upwelling events.
Tronje P. Kemena, Angela Landolfi, Andreas Oschlies, Klaus Wallmann, and Andrew W. Dale
Earth Syst. Dynam., 10, 539–553, https://doi.org/10.5194/esd-10-539-2019, https://doi.org/10.5194/esd-10-539-2019, 2019
Short summary
Short summary
Oceanic deoxygenation is driven by climate change in several areas of the global ocean. Measurements indicate that ocean volumes with very low oxygen levels expand, with consequences for marine organisms and fishery. We found climate-change-driven phosphorus (P) input in the ocean is hereby an important driver for deoxygenation on longer timescales with effects in the next millennia.
Johannes Pein, Annika Eisele, Richard Hofmeister, Tina Sanders, Ute Daewel, Emil V. Stanev, Justus van Beusekom, Joanna Staneva, and Corinna Schrum
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-265, https://doi.org/10.5194/bg-2019-265, 2019
Revised manuscript not accepted
Short summary
Short summary
The Elbe estuary is subject to vigorous tidal forcing from the sea side and considerable biological inputs from the land side. Our 3D numerical coupled physical-biogeochemical integrates these forcing signals and provides highly realistic hindcasts of the associated dynamics. Model simulations show that the freshwater part of Elbe estuary is inhabited by plankton. According to simulations these organism play a key role in converting organic inputs into nitrate, the major inorganic nutrient.
Tim Fischer, Annette Kock, Damian L. Arévalo-Martínez, Marcus Dengler, Peter Brandt, and Hermann W. Bange
Biogeosciences, 16, 2307–2328, https://doi.org/10.5194/bg-16-2307-2019, https://doi.org/10.5194/bg-16-2307-2019, 2019
Short summary
Short summary
We investigated air–sea gas exchange in oceanic upwelling regions for the case of nitrous oxide off Peru. In this region, routine concentration measurements from ships at 5 m or 10 m depth prove to overestimate surface (bulk) concentration. Thus, standard estimates of gas exchange will show systematic error. This is due to very shallow stratified layers that inhibit exchange between surface water and waters below and can exist for several days. Maximum bias occurs in moderate wind conditions.
Marlène Lavrieux, Axel Birkholz, Katrin Meusburger, Guido L. B. Wiesenberg, Adrian Gilli, Christian Stamm, and Christine Alewell
Biogeosciences, 16, 2131–2146, https://doi.org/10.5194/bg-16-2131-2019, https://doi.org/10.5194/bg-16-2131-2019, 2019
Short summary
Short summary
A fingerprinting approach using compound-specific stable isotopes was applied to a lake sediment core to reconstruct erosion processes over the past 150 years in a Swiss catchment. Even though the reconstruction of land use and eutrophication history was successful, the observation of comparatively low δ13C values of plant-derived fatty acids in the sediment suggests their alteration within the lake. Thus, their use as a tool for source attribution in sediment cores needs further investigation.
Qixing Ji, Mark A. Altabet, Hermann W. Bange, Michelle I. Graco, Xiao Ma, Damian L. Arévalo-Martínez, and Damian S. Grundle
Biogeosciences, 16, 2079–2093, https://doi.org/10.5194/bg-16-2079-2019, https://doi.org/10.5194/bg-16-2079-2019, 2019
Short summary
Short summary
A strong El Niño event occurred in the Peruvian coastal region in 2015–2016, during which higher sea surface temperatures co-occurred with significantly lower sea-to-air fluxes of nitrous oxide, an important greenhouse gas and ozone depletion agent. Stratified water column during El Niño retained a larger amount of nitrous oxide that was produced via multiple microbial pathways; and intense nitrous oxide effluxes could occur when normal upwelling is resumed after El Niño.
Robert Scott Winton, Elisa Calamita, and Bernhard Wehrli
Biogeosciences, 16, 1657–1671, https://doi.org/10.5194/bg-16-1657-2019, https://doi.org/10.5194/bg-16-1657-2019, 2019
Short summary
Short summary
A global boom in dam construction throughout the world’s tropics motivated us to review and synthesize information on the water quality impacts of dams with a focus on low-latitude contexts and scope for mitigation. Sediment trapping and reservoir stratification are key process driving chemical and ecological impacts on tropical rivers. We analyze the 54 most-voluminous low-latitude reservoirs and find that stratification seems to be a ubiquitous phenomenon.
Hagen Radtke, Marko Lipka, Dennis Bunke, Claudia Morys, Jana Woelfel, Bronwyn Cahill, Michael E. Böttcher, Stefan Forster, Thomas Leipe, Gregor Rehder, and Thomas Neumann
Geosci. Model Dev., 12, 275–320, https://doi.org/10.5194/gmd-12-275-2019, https://doi.org/10.5194/gmd-12-275-2019, 2019
Short summary
Short summary
This paper describes a coupled benthic–pelagic biogeochemical model, ERGOM-SED. We demonstrate its use in a one-dimensional physical model, which is horizontally integrated and vertically resolved. We describe the application of the model to seven stations in the south-western Baltic Sea. The model was calibrated using pore water profiles from these stations. We compare the model results to these and to measured sediment compositions, benthopelagic fluxes and bioturbation intensities.
Beate Stawiarski, Stefan Otto, Volker Thiel, Ulf Gräwe, Natalie Loick-Wilde, Anna K. Wittenborn, Stefan Schloemer, Janine Wäge, Gregor Rehder, Matthias Labrenz, Norbert Wasmund, and Oliver Schmale
Biogeosciences, 16, 1–16, https://doi.org/10.5194/bg-16-1-2019, https://doi.org/10.5194/bg-16-1-2019, 2019
Short summary
Short summary
The understanding of surface water methane production in the world oceans is still poor. By combining field studies and incubation experiments, our investigations suggest that zooplankton contributes to subthermocline methane enrichments in the central Baltic Sea by methane production within the digestive tract of copepods and/or by methane production through release of methane precursor substances into the surrounding water, followed by microbial degradation to methane.
Corinne Le Quéré, Robbie M. Andrew, Pierre Friedlingstein, Stephen Sitch, Judith Hauck, Julia Pongratz, Penelope A. Pickers, Jan Ivar Korsbakken, Glen P. Peters, Josep G. Canadell, Almut Arneth, Vivek K. Arora, Leticia Barbero, Ana Bastos, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Philippe Ciais, Scott C. Doney, Thanos Gkritzalis, Daniel S. Goll, Ian Harris, Vanessa Haverd, Forrest M. Hoffman, Mario Hoppema, Richard A. Houghton, George Hurtt, Tatiana Ilyina, Atul K. Jain, Truls Johannessen, Chris D. Jones, Etsushi Kato, Ralph F. Keeling, Kees Klein Goldewijk, Peter Landschützer, Nathalie Lefèvre, Sebastian Lienert, Zhu Liu, Danica Lombardozzi, Nicolas Metzl, David R. Munro, Julia E. M. S. Nabel, Shin-ichiro Nakaoka, Craig Neill, Are Olsen, Tsueno Ono, Prabir Patra, Anna Peregon, Wouter Peters, Philippe Peylin, Benjamin Pfeil, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Matthias Rocher, Christian Rödenbeck, Ute Schuster, Jörg Schwinger, Roland Séférian, Ingunn Skjelvan, Tobias Steinhoff, Adrienne Sutton, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco N. Tubiello, Ingrid T. van der Laan-Luijkx, Guido R. van der Werf, Nicolas Viovy, Anthony P. Walker, Andrew J. Wiltshire, Rebecca Wright, Sönke Zaehle, and Bo Zheng
Earth Syst. Sci. Data, 10, 2141–2194, https://doi.org/10.5194/essd-10-2141-2018, https://doi.org/10.5194/essd-10-2141-2018, 2018
Short summary
Short summary
The Global Carbon Budget 2018 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Ulrike Braeckman, Felix Janssen, Gaute Lavik, Marcus Elvert, Hannah Marchant, Caroline Buckner, Christina Bienhold, and Frank Wenzhöfer
Biogeosciences, 15, 6537–6557, https://doi.org/10.5194/bg-15-6537-2018, https://doi.org/10.5194/bg-15-6537-2018, 2018
Short summary
Short summary
Global warming has altered Arctic phytoplankton communities, with unknown effects on deep-sea communities that depend strongly on food produced at the surface. We compared the responses of Arctic deep-sea benthos to input of phytodetritus from diatoms and coccolithophorids. Coccolithophorid carbon was 5× less recycled than diatom carbon. The utilization of the coccolithophorid carbon may be less efficient, so a shift from diatom to coccolithophorid blooms could entail a delay in carbon cycling.
Xi Wen, Viktoria Unger, Gerald Jurasinski, Franziska Koebsch, Fabian Horn, Gregor Rehder, Torsten Sachs, Dominik Zak, Gunnar Lischeid, Klaus-Holger Knorr, Michael E. Böttcher, Matthias Winkel, Paul L. E. Bodelier, and Susanne Liebner
Biogeosciences, 15, 6519–6536, https://doi.org/10.5194/bg-15-6519-2018, https://doi.org/10.5194/bg-15-6519-2018, 2018
Short summary
Short summary
Rewetting drained peatlands may lead to prolonged emission of the greenhouse gas methane, but the underlying factors are not well described. In this study, we found two rewetted fens with known high methane fluxes had a high ratio of microbial methane producers to methane consumers and a low abundance of methane consumers compared to pristine wetlands. We therefore suggest abundances of methane-cycling microbes as potential indicators for prolonged high methane emissions in rewetted peatlands.
Samuel T. Wilson, Hermann W. Bange, Damian L. Arévalo-Martínez, Jonathan Barnes, Alberto V. Borges, Ian Brown, John L. Bullister, Macarena Burgos, David W. Capelle, Michael Casso, Mercedes de la Paz, Laura Farías, Lindsay Fenwick, Sara Ferrón, Gerardo Garcia, Michael Glockzin, David M. Karl, Annette Kock, Sarah Laperriere, Cliff S. Law, Cara C. Manning, Andrew Marriner, Jukka-Pekka Myllykangas, John W. Pohlman, Andrew P. Rees, Alyson E. Santoro, Philippe D. Tortell, Robert C. Upstill-Goddard, David P. Wisegarver, Gui-Ling Zhang, and Gregor Rehder
Biogeosciences, 15, 5891–5907, https://doi.org/10.5194/bg-15-5891-2018, https://doi.org/10.5194/bg-15-5891-2018, 2018
Short summary
Short summary
To determine the variability between independent measurements of dissolved methane and nitrous oxide, seawater samples were analyzed by multiple laboratories. The results revealed the influences of the different parts of the analytical process, from the initial sample collection to the calculation of the final concentrations. Recommendations are made to improve dissolved methane and nitrous oxide measurements to help preclude future analytical discrepancies between laboratories.
Konstantin Stolpovsky, Andrew W. Dale, and Klaus Wallmann
Biogeosciences, 15, 3391–3407, https://doi.org/10.5194/bg-15-3391-2018, https://doi.org/10.5194/bg-15-3391-2018, 2018
Short summary
Short summary
The paper describes a new way to parameterize G-type models in marine sediments using data about reactivity of organic carbon sinking to the seafloor.
Corinne Le Quéré, Robbie M. Andrew, Pierre Friedlingstein, Stephen Sitch, Julia Pongratz, Andrew C. Manning, Jan Ivar Korsbakken, Glen P. Peters, Josep G. Canadell, Robert B. Jackson, Thomas A. Boden, Pieter P. Tans, Oliver D. Andrews, Vivek K. Arora, Dorothee C. E. Bakker, Leticia Barbero, Meike Becker, Richard A. Betts, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Philippe Ciais, Catherine E. Cosca, Jessica Cross, Kim Currie, Thomas Gasser, Ian Harris, Judith Hauck, Vanessa Haverd, Richard A. Houghton, Christopher W. Hunt, George Hurtt, Tatiana Ilyina, Atul K. Jain, Etsushi Kato, Markus Kautz, Ralph F. Keeling, Kees Klein Goldewijk, Arne Körtzinger, Peter Landschützer, Nathalie Lefèvre, Andrew Lenton, Sebastian Lienert, Ivan Lima, Danica Lombardozzi, Nicolas Metzl, Frank Millero, Pedro M. S. Monteiro, David R. Munro, Julia E. M. S. Nabel, Shin-ichiro Nakaoka, Yukihiro Nojiri, X. Antonio Padin, Anna Peregon, Benjamin Pfeil, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Janet Reimer, Christian Rödenbeck, Jörg Schwinger, Roland Séférian, Ingunn Skjelvan, Benjamin D. Stocker, Hanqin Tian, Bronte Tilbrook, Francesco N. Tubiello, Ingrid T. van der Laan-Luijkx, Guido R. van der Werf, Steven van Heuven, Nicolas Viovy, Nicolas Vuichard, Anthony P. Walker, Andrew J. Watson, Andrew J. Wiltshire, Sönke Zaehle, and Dan Zhu
Earth Syst. Sci. Data, 10, 405–448, https://doi.org/10.5194/essd-10-405-2018, https://doi.org/10.5194/essd-10-405-2018, 2018
Short summary
Short summary
The Global Carbon Budget 2017 describes data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. It is the 12th annual update and the 6th published in this journal.
Johanna Maltby, Lea Steinle, Carolin R. Löscher, Hermann W. Bange, Martin A. Fischer, Mark Schmidt, and Tina Treude
Biogeosciences, 15, 137–157, https://doi.org/10.5194/bg-15-137-2018, https://doi.org/10.5194/bg-15-137-2018, 2018
Short summary
Short summary
The activity and environmental controls of methanogenesis (MG) within the sulfate-reducing zone (0–30 cm below the seafloor) were investigated in organic-rich sediments of the seasonally hypoxic Eckernförde Bay, SW Baltic Sea. MG activity was mostly linked to non-competitive substrates. The major controls identified were organic matter availability, C / N, temperature, and O2 in the water column, revealing higher rates in warm, stratified, hypoxic seasons compared to colder, oxygenated seasons.
Jukka-Pekka Myllykangas, Tom Jilbert, Gunnar Jakobs, Gregor Rehder, Jan Werner, and Susanna Hietanen
Earth Syst. Dynam., 8, 817–826, https://doi.org/10.5194/esd-8-817-2017, https://doi.org/10.5194/esd-8-817-2017, 2017
Short summary
Short summary
The deep waters of the Baltic Sea host an expanding
dead zone, where low-oxygen conditions favour the natural production of two strong greenhouse gases, methane and nitrous oxide. Oxygen is introduced into the deeps only during rare
salt pulses. We studied the effects of a recent salt pulse on Baltic greenhouse gas production. We found that where oxygen was introduced, methane was largely removed, while nitrous oxide production increased, indicating strong effects on greenhouse gas dynamics.
S. Nemiah Ladd, Nathalie Dubois, and Carsten J. Schubert
Biogeosciences, 14, 3979–3994, https://doi.org/10.5194/bg-14-3979-2017, https://doi.org/10.5194/bg-14-3979-2017, 2017
Short summary
Short summary
Hydrogen isotopes of lipids provide valuable information about microbial activity, climate, and environmental stress. We show that heavy hydrogen in fatty acids declines from spring to summer in a nutrient-rich and a nutrient-poor lake and that the effect is nearly 3 times as big in the former. This effect is likely a combination of increased biomass from algae, warmer temperatures, and higher algal growth rates.
Chun-Ying Liu, Wei-Hua Feng, Ye Tian, Gui-Peng Yang, Pei-Feng Li, and Hermann W. Bange
Ocean Sci., 13, 623–632, https://doi.org/10.5194/os-13-623-2017, https://doi.org/10.5194/os-13-623-2017, 2017
Short summary
Short summary
We developed a new method for the determination of dissolved nitric oxide (NO) in discrete seawater samples based on the combination of a purge-and-trap setup and a fluorometric detection of NO. With this method we have a reliable and comparably easy to use method to measure oceanic NO surface concentrations, which can be used to decipher both its temporal and spatial distributions as well as its biogeochemical pathways in the oceans.
Thomas Steinsberger, Martin Schmid, Alfred Wüest, Robert Schwefel, Bernhard Wehrli, and Beat Müller
Biogeosciences, 14, 3275–3285, https://doi.org/10.5194/bg-14-3275-2017, https://doi.org/10.5194/bg-14-3275-2017, 2017
Short summary
Short summary
Based on a broad dataset of lake sediment analysis and porewater measurements from various Swiss lakes, this paper argues that the accumulation of organic carbon in the sediment is one of the main driving forces for the generation of reduced substances such as methane and ammonia. These substances significantly contribute to the hypolimnetic oxygen consumption. The relationships presented help to evaluate the scale of the flux of reduced substances where no direct measurements are available.
Burkard Baschek, Friedhelm Schroeder, Holger Brix, Rolf Riethmüller, Thomas H. Badewien, Gisbert Breitbach, Bernd Brügge, Franciscus Colijn, Roland Doerffer, Christiane Eschenbach, Jana Friedrich, Philipp Fischer, Stefan Garthe, Jochen Horstmann, Hajo Krasemann, Katja Metfies, Lucas Merckelbach, Nino Ohle, Wilhelm Petersen, Daniel Pröfrock, Rüdiger Röttgers, Michael Schlüter, Jan Schulz, Johannes Schulz-Stellenfleth, Emil Stanev, Joanna Staneva, Christian Winter, Kai Wirtz, Jochen Wollschläger, Oliver Zielinski, and Friedwart Ziemer
Ocean Sci., 13, 379–410, https://doi.org/10.5194/os-13-379-2017, https://doi.org/10.5194/os-13-379-2017, 2017
Short summary
Short summary
The Coastal Observing System for Northern and Arctic Seas (COSYNA) was established in order to better understand the complex interdisciplinary processes of northern seas and the Arctic coasts in a changing environment. Particular focus is given to the heavily used German Bight in the North Sea. The automated observing and modelling system is designed to monitor real-time conditions, to provide short-term forecasts and data products, and to assess the impact of anthropogenically induced change.
Kathrin Wahle, Joanna Staneva, Wolfgang Koch, Luciana Fenoglio-Marc, Ha T. M. Ho-Hagemann, and Emil V. Stanev
Ocean Sci., 13, 289–301, https://doi.org/10.5194/os-13-289-2017, https://doi.org/10.5194/os-13-289-2017, 2017
Short summary
Short summary
Reduction of wave forecasting errors is a challenge, especially in dynamically complicated coastal ocean areas such as the southern part of the North Sea area. We study the effects of coupling between an atmospheric and two nested-grid wind wave models. Comparisons with data from in situ and satellite altimeter observations indicate that two-way coupling improves the simulation of wind and wave parameters of the model and justifies its implementation for both operational and climate simulation.
Lea Steinle, Johanna Maltby, Tina Treude, Annette Kock, Hermann W. Bange, Nadine Engbersen, Jakob Zopfi, Moritz F. Lehmann, and Helge Niemann
Biogeosciences, 14, 1631–1645, https://doi.org/10.5194/bg-14-1631-2017, https://doi.org/10.5194/bg-14-1631-2017, 2017
Short summary
Short summary
Large amounts of methane are produced in anoxic, coastal sediments, from which it can seep into the overlying water column. Aerobic oxidation of methane (MOx) mediated by methanotrophic bacteria is an important sink for methane before its evasion to the atmosphere. In a 2-year seasonal study, we investigated the spatio-temporal variability of MOx in a seasonally hypoxic coastal inlet using radiotracer-based methods. In experiments, we assessed the effect of variable oxygen concentrations on MOx.
Amelie Driemel, Eberhard Fahrbach, Gerd Rohardt, Agnieszka Beszczynska-Möller, Antje Boetius, Gereon Budéus, Boris Cisewski, Ralph Engbrodt, Steffen Gauger, Walter Geibert, Patrizia Geprägs, Dieter Gerdes, Rainer Gersonde, Arnold L. Gordon, Hannes Grobe, Hartmut H. Hellmer, Enrique Isla, Stanley S. Jacobs, Markus Janout, Wilfried Jokat, Michael Klages, Gerhard Kuhn, Jens Meincke, Sven Ober, Svein Østerhus, Ray G. Peterson, Benjamin Rabe, Bert Rudels, Ursula Schauer, Michael Schröder, Stefanie Schumacher, Rainer Sieger, Jüri Sildam, Thomas Soltwedel, Elena Stangeew, Manfred Stein, Volker H Strass, Jörn Thiede, Sandra Tippenhauer, Cornelis Veth, Wilken-Jon von Appen, Marie-France Weirig, Andreas Wisotzki, Dieter A. Wolf-Gladrow, and Torsten Kanzow
Earth Syst. Sci. Data, 9, 211–220, https://doi.org/10.5194/essd-9-211-2017, https://doi.org/10.5194/essd-9-211-2017, 2017
Short summary
Short summary
Our oceans are always in motion – huge water masses are circulated by winds and by global seawater density gradients resulting from different water temperatures and salinities. Measuring temperature and salinity of the world's oceans is crucial e.g. to understand our climate. Since 1983, the research icebreaker Polarstern has been the basis of numerous water profile measurements in the Arctic and the Antarctic. We report on a unique collection of 33 years of polar salinity and temperature data.
Stefano Bonaglia, Astrid Hylén, Jayne E. Rattray, Mikhail Y. Kononets, Nils Ekeroth, Per Roos, Bo Thamdrup, Volker Brüchert, and Per O. J. Hall
Biogeosciences, 14, 285–300, https://doi.org/10.5194/bg-14-285-2017, https://doi.org/10.5194/bg-14-285-2017, 2017
Short summary
Short summary
Understanding nitrogen (N) cycling mechanisms in the ocean is crucial for improving ecosystem management. Here we study N processes by in situ lander and isotope tracer techniques in – so far overlooked – sediments with low organic loads. Denitrification and anammox are the main N transformation processes. However, we demonstrate high contribution of dissimilatory nitrate reduction to ammonium, which recycles a major portion of fixed N to the water column and sustains primary production.
Joanna Staneva, Kathrin Wahle, Wolfgang Koch, Arno Behrens, Luciana Fenoglio-Marc, and Emil V. Stanev
Nat. Hazards Earth Syst. Sci., 16, 2373–2389, https://doi.org/10.5194/nhess-16-2373-2016, https://doi.org/10.5194/nhess-16-2373-2016, 2016
Short summary
Short summary
This study addresses the impact of wind, waves, tidal forcing and baroclinicity on the sea level of the German Bight during extreme storm events. The role of wave-induced processes, tides and baroclinicity is quantified, and the results are compared with in situ measurements and satellite data. Considering a wave-dependent approach and baroclinicity, the surge is significantly enhanced in the coastal areas and the model results are closer to observations, especially during the extreme storm.
Emil V. Stanev, Johannes Schulz-Stellenfleth, Joanna Staneva, Sebastian Grayek, Sebastian Grashorn, Arno Behrens, Wolfgang Koch, and Johannes Pein
Ocean Sci., 12, 1105–1136, https://doi.org/10.5194/os-12-1105-2016, https://doi.org/10.5194/os-12-1105-2016, 2016
Short summary
Short summary
This paper describes coastal ocean forecasting practices exemplified for the North Sea and Baltic Sea. It identifies new challenges, most of which are associated with the nonlinear behavior of coastal oceans. It describes the assimilation of remote sensing, in situ and HF radar data, prediction of wind waves and storm surges, as well as applications to search and rescue operations. Seamless applications to coastal and estuarine modeling are also presented.
Jun She, Icarus Allen, Erik Buch, Alessandro Crise, Johnny A. Johannessen, Pierre-Yves Le Traon, Urmas Lips, Glenn Nolan, Nadia Pinardi, Jan H. Reißmann, John Siddorn, Emil Stanev, and Henning Wehde
Ocean Sci., 12, 953–976, https://doi.org/10.5194/os-12-953-2016, https://doi.org/10.5194/os-12-953-2016, 2016
Short summary
Short summary
This white paper addresses key scientific challenges and research priorities for the development of operational oceanography in Europe for the next 5–10 years. Knowledge gaps and deficiencies are identified in relation to common scientific challenges in four EuroGOOS knowledge areas: European ocean observations, modelling and forecasting technology, coastal operational oceanography, and operational ecology.
Jessica Gier, Stefan Sommer, Carolin R. Löscher, Andrew W. Dale, Ruth A. Schmitz, and Tina Treude
Biogeosciences, 13, 4065–4080, https://doi.org/10.5194/bg-13-4065-2016, https://doi.org/10.5194/bg-13-4065-2016, 2016
Short summary
Short summary
Benthic nitrogen fixation and sulfate reduction were investigated in the Peruvian oxygen minimum zone. The data suggest a coupling of both activities to a large extent, but that also sulfide and organic matter availability are controlling the benthic diazotrophy in this area. The molecular analysis confirms the presence of heterotrophic diazotrophs. This work improves our understanding of N cycling in OMZ sediments and the understanding of N sources in the marine environment.
Ralf D. Prien and Detlef E. Schulz-Bull
Ocean Sci., 12, 899–907, https://doi.org/10.5194/os-12-899-2016, https://doi.org/10.5194/os-12-899-2016, 2016
Short summary
Short summary
A profiling mooring with an interdisciplinary suite of sensors for water depths up to 300 m is described in this note. It can be programmed to take profiles through the water column at set times or intervals and with the standard set of batteries is able to profile about 34 km in total (e.g. 200 profiles of 170 m profiling each).
The mooring was designed to observe the dynamics of the redoxcline in the Gotland Basin over periods of up to 3 months.
Lothar Stramma, Tim Fischer, Damian S. Grundle, Gerd Krahmann, Hermann W. Bange, and Christa A. Marandino
Ocean Sci., 12, 861–873, https://doi.org/10.5194/os-12-861-2016, https://doi.org/10.5194/os-12-861-2016, 2016
Short summary
Short summary
Results from a research cruise on R/V Sonne to the eastern tropical Pacific in October 2015 during the 2015–2016 El Niño show the transition of current, hydrographic, and nutrient conditions to El Niño conditions in the eastern tropical Pacific in October 2015. Although in early 2015 the El Niño was strong and in October 2015 showed a clear El Niño influence on the EUC, in the eastern tropical Pacific the measurements only showed developing El Niño water mass distributions.
Carolin R. Löscher, Hermann W. Bange, Ruth A. Schmitz, Cameron M. Callbeck, Anja Engel, Helena Hauss, Torsten Kanzow, Rainer Kiko, Gaute Lavik, Alexandra Loginova, Frank Melzner, Judith Meyer, Sven C. Neulinger, Markus Pahlow, Ulf Riebesell, Harald Schunck, Sören Thomsen, and Hannes Wagner
Biogeosciences, 13, 3585–3606, https://doi.org/10.5194/bg-13-3585-2016, https://doi.org/10.5194/bg-13-3585-2016, 2016
Short summary
Short summary
The ocean loses oxygen due to climate change. Addressing this issue in tropical ocean regions (off Peru and Mauritania), we aimed to understand the effects of oxygen depletion on various aspects of marine biogeochemistry, including primary production and export production, the nitrogen cycle, greenhouse gas production, organic matter fluxes and remineralization, and the role of zooplankton and viruses.
Joanna Staneva, Kathrin Wahle, Heinz Günther, and Emil Stanev
Ocean Sci., 12, 797–806, https://doi.org/10.5194/os-12-797-2016, https://doi.org/10.5194/os-12-797-2016, 2016
Short summary
Short summary
This study addresses the impact of coupling between wind wave and circulation models on the quality of coastal ocean predicting systems. This topic reflects the increased interest in operational oceanography to reduce prediction errors of state estimates at coastal scales. The improved skill of the coupled forecasts compared to the non-coupled ones, in particular during extreme events, justifies the further enhancements of coastal operational systems by including wind wave models.
Pei-Chuan Chuang, Megan B. Young, Andrew W. Dale, Laurence G. Miller, Jorge A. Herrera-Silveira, and Adina Paytan
Biogeosciences, 13, 2981–3001, https://doi.org/10.5194/bg-13-2981-2016, https://doi.org/10.5194/bg-13-2981-2016, 2016
Short summary
Short summary
A transport-reaction model was used to simulate porewater methane and sulfate concentrations. Model results and sediment slurry incubation experiments show high methane production rates supported by non-competitive substrates and ample dissolved and labile organic matter as well as methane from deeper sediment through bubbles dissolution and diffusion. The shallow methane production and accumulation depths in these sediments promote high methane fluxes to the water column and atmosphere.
Carolin R. Löscher, Annie Bourbonnais, Julien Dekaezemacker, Chawalit N. Charoenpong, Mark A. Altabet, Hermann W. Bange, Rena Czeschel, Chris Hoffmann, and Ruth Schmitz
Biogeosciences, 13, 2889–2899, https://doi.org/10.5194/bg-13-2889-2016, https://doi.org/10.5194/bg-13-2889-2016, 2016
Short summary
Short summary
The ocean is full of eddies and they play a key role for ocean biogeochemistry. In order to understand dinitrogen (N2) fixation, one major control of oceanic primary production, we investigated three eddies in the eastern tropical South Pacific off Peru. We conducted the first detailed survey and found increased N2 fixation in the oxygen-depleted cores of anticyclonic mode water eddies. Taken together, we could – for the first time – show that eddies play an important role in N2 fixation off Peru.
Denise Müller, Hermann W. Bange, Thorsten Warneke, Tim Rixen, Moritz Müller, Aazani Mujahid, and Justus Notholt
Biogeosciences, 13, 2415–2428, https://doi.org/10.5194/bg-13-2415-2016, https://doi.org/10.5194/bg-13-2415-2016, 2016
Short summary
Short summary
Estuaries act as sources of the greenhouse gases nitrous oxide (N2O) and methane (CH4) to the atmosphere. We provide first measurements of N2O and CH4 in two estuaries in north-western Borneo, a region which is dominated by peatlands. We show that N2O and CH4 concentrations in these estuaries are moderate despite high organic carbon loads, that nutrient enhancement does not lead to enhanced N2O emissions, and that the wet season dominates the variability of the emissions in these systems.
Happy Hu, Annie Bourbonnais, Jennifer Larkum, Hermann W. Bange, and Mark A. Altabet
Biogeosciences, 13, 1453–1468, https://doi.org/10.5194/bg-13-1453-2016, https://doi.org/10.5194/bg-13-1453-2016, 2016
Ulrike Lomnitz, Stefan Sommer, Andrew W. Dale, Carolin R. Löscher, Anna Noffke, Klaus Wallmann, and Christian Hensen
Biogeosciences, 13, 1367–1386, https://doi.org/10.5194/bg-13-1367-2016, https://doi.org/10.5194/bg-13-1367-2016, 2016
Short summary
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.
Arthur Capet, Emil V. Stanev, Jean-Marie Beckers, James W. Murray, and Marilaure Grégoire
Biogeosciences, 13, 1287–1297, https://doi.org/10.5194/bg-13-1287-2016, https://doi.org/10.5194/bg-13-1287-2016, 2016
Short summary
Short summary
We show that the Black Sea oxygen inventory has decreased by 44 % from 1955 to 2015, while oxygen penetration depth decreased from 140 to 90 m. A transient increase of the oxygen inventory during 1985–1995 supported the perception of a stable oxic interface and of a general recovery of the Black Sea after a strong eutrophication phase (1970–1990). Instead, we show that ongoing high oxygen consumption was masked by high ventilation rates, which are now limited by atmospheric warming.
Damian L. Arévalo-Martínez, Annette Kock, Carolin R. Löscher, Ruth A. Schmitz, Lothar Stramma, and Hermann W. Bange
Biogeosciences, 13, 1105–1118, https://doi.org/10.5194/bg-13-1105-2016, https://doi.org/10.5194/bg-13-1105-2016, 2016
Short summary
Short summary
We present the first measurements of N2O across three mesoscale eddies in the eastern tropical South Pacific. Eddie's vertical structure, offshore transport, properties during its formation and near-surface primary production determined the N2O distribution. Substantial depletion of N2O within the core of anticyclonic eddies suggests that although these are transient features, N-loss processes within their centres can lead to an enhanced N2O sink which is not accounted for in marine N2O budgets.
A. Kock, D. L. Arévalo-Martínez, C. R. Löscher, and H. W. Bange
Biogeosciences, 13, 827–840, https://doi.org/10.5194/bg-13-827-2016, https://doi.org/10.5194/bg-13-827-2016, 2016
Short summary
Short summary
We measured the nitrous oxide (N2O) distribution in the water column in the oxygen minimum zone off Peru, an area with extremely high N2O emissions. Our data show very variable and often very high N2O concentrations in the water column at the coast, which lead to high N2O emissions when these waters are brought to the surface. The very high N2O production off Peru may be caused by high nutrient turnover rates together with rapid changes in the oxygen concentrations.
A. R. Baker, M. Thomas, H. W. Bange, and E. Plasencia Sánchez
Biogeosciences, 13, 817–825, https://doi.org/10.5194/bg-13-817-2016, https://doi.org/10.5194/bg-13-817-2016, 2016
Short summary
Short summary
Concentrations of major ions and trace metals were measured in aerosols off the coast of Peru in December 2012. A few trace metals (iron, copper, nickel, and cobalt) had anomalously high concentrations, which may be associated with industrial metal smelting activities in the region. The atmosphere appears to supply an excess of iron (relative to atmospheric nitrogen supply) to the phytoplankton community of the Peruvian upwelling system.
D. Müller, T. Warneke, T. Rixen, M. Müller, A. Mujahid, H. W. Bange, and J. Notholt
Biogeosciences, 13, 691–705, https://doi.org/10.5194/bg-13-691-2016, https://doi.org/10.5194/bg-13-691-2016, 2016
Short summary
Short summary
We studied organic carbon and the dissolved greenhouse gases carbon dioxide (CO2) and carbon monoxide (CO) in two estuaries in Sarawak, Malaysia, whose coast is covered by carbon-rich peatlands. The estuaries received terrestrial organic carbon from peat-draining tributaries. A large fraction was converted to CO2 and a minor fraction to CO. Both gases were released to the atmosphere. This shows how these estuaries function as efficient filters between land and ocean in this important region.
J. Maltby, S. Sommer, A. W. Dale, and T. Treude
Biogeosciences, 13, 283–299, https://doi.org/10.5194/bg-13-283-2016, https://doi.org/10.5194/bg-13-283-2016, 2016
Short summary
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.
C. Le Quéré, R. Moriarty, R. M. Andrew, J. G. Canadell, S. Sitch, J. I. Korsbakken, P. Friedlingstein, G. P. Peters, R. J. Andres, T. A. Boden, R. A. Houghton, J. I. House, R. F. Keeling, P. Tans, A. Arneth, D. C. E. Bakker, L. Barbero, L. Bopp, J. Chang, F. Chevallier, L. P. Chini, P. Ciais, M. Fader, R. A. Feely, T. Gkritzalis, I. Harris, J. Hauck, T. Ilyina, A. K. Jain, E. Kato, V. Kitidis, K. Klein Goldewijk, C. Koven, P. Landschützer, S. K. Lauvset, N. Lefèvre, A. Lenton, I. D. Lima, N. Metzl, F. Millero, D. R. Munro, A. Murata, J. E. M. S. Nabel, S. Nakaoka, Y. Nojiri, K. O'Brien, A. Olsen, T. Ono, F. F. Pérez, B. Pfeil, D. Pierrot, B. Poulter, G. Rehder, C. Rödenbeck, S. Saito, U. Schuster, J. Schwinger, R. Séférian, T. Steinhoff, B. D. Stocker, A. J. Sutton, T. Takahashi, B. Tilbrook, I. T. van der Laan-Luijkx, G. R. van der Werf, S. van Heuven, D. Vandemark, N. Viovy, A. Wiltshire, S. Zaehle, and N. Zeng
Earth Syst. Sci. Data, 7, 349–396, https://doi.org/10.5194/essd-7-349-2015, https://doi.org/10.5194/essd-7-349-2015, 2015
Short summary
Short summary
Accurate assessment of anthropogenic carbon dioxide emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to understand the global carbon cycle, support the development of climate policies, and project future climate change. We describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on a range of data and models and their interpretation by a broad scientific community.
H. E. Lutterbeck and H. W. Bange
Ocean Sci., 11, 937–946, https://doi.org/10.5194/os-11-937-2015, https://doi.org/10.5194/os-11-937-2015, 2015
P. Steeb, S. Krause, P. Linke, C. Hensen, A. W. Dale, M. Nuzzo, and T. Treude
Biogeosciences, 12, 6687–6706, https://doi.org/10.5194/bg-12-6687-2015, https://doi.org/10.5194/bg-12-6687-2015, 2015
Short summary
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. Varenik, S. Konovalov, and S. Stanichny
Biogeosciences, 12, 6479–6491, https://doi.org/10.5194/bg-12-6479-2015, https://doi.org/10.5194/bg-12-6479-2015, 2015
Short summary
Short summary
Atmospheric deposition of inorganic fixed nitrogen has been evaluated and quantified for the Black Sea at different spatial and temporal scales. The effect of this deposition has appeared comparable to riverine load of nutrients. This atmospheric deposition can dramatically increase primary production with the major effects for off-shore regions. It does support the currently highly eutrophic state of the Black Sea and prevents rehabilitation of this ecosystem.
L. Holinde, T. H. Badewien, J. A. Freund, E. V. Stanev, and O. Zielinski
Earth Syst. Sci. Data, 7, 289–297, https://doi.org/10.5194/essd-7-289-2015, https://doi.org/10.5194/essd-7-289-2015, 2015
Short summary
Short summary
We present water level data derived from long-term measurements of water pressure at the Time Series Station Spiekeroog (southern North Sea). Problems addressed during data processing include outliers, data gaps and sensor drift. For quality control, we compared the processed data to measurements of water level obtained nearby. We also carried out a storm flood analysis and a Fourier analysis to identify major tidal components.
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, https://doi.org/10.5194/bg-12-5075-2015, https://doi.org/10.5194/bg-12-5075-2015, 2015
T. J. Sherwin, D. Aleynik, E. Dumont, and M. E. Inall
Ocean Sci., 11, 343–359, https://doi.org/10.5194/os-11-343-2015, https://doi.org/10.5194/os-11-343-2015, 2015
Short summary
Short summary
The Rockall Trough feeds warm salty water to Polar regions and the European Shelf. Detailed observations from an underwater glider show that a) the meandering surface current field in the central trough is driven by deep eddies; b) chance circulations deflect the eastern slope current and warm the western side; c) and altimeter observations omit the mean flow in the narrow slope current. There are wider implications for satellite altimeter observations, ocean monitoring and ocean model results.
A. W. Dale, S. Sommer, U. Lomnitz, I. Montes, T. Treude, V. Liebetrau, J. Gier, C. Hensen, M. Dengler, K. Stolpovsky, L. D. Bryant, and K. Wallmann
Biogeosciences, 12, 1537–1559, https://doi.org/10.5194/bg-12-1537-2015, https://doi.org/10.5194/bg-12-1537-2015, 2015
J. Schönfeld, W. Kuhnt, Z. Erdem, S. Flögel, N. Glock, M. Aquit, M. Frank, and A. Holbourn
Biogeosciences, 12, 1169–1189, https://doi.org/10.5194/bg-12-1169-2015, https://doi.org/10.5194/bg-12-1169-2015, 2015
Short summary
Short summary
Today’s oceans show distinct mid-depth oxygen minima while whole oceanic basins became transiently anoxic in the Mesozoic. To constrain past bottom-water oxygenation, we compared sediments from the Peruvian OMZ with the Cenomanian OAE 2 from Morocco. Corg accumulation rates in laminated OAE 2 sections match Holocene rates off Peru. Laminated deposits are found at oxygen levels of < 7µmol kg-1; crab burrows appear at 10µmol kg-1 today, both defining threshold values for palaeoreconstructions.
C. Beck, C. Campos, K. K. Eriş, N. Çağatay, B. Mercier de Lepinay, and F. Jouanne
Nat. Hazards Earth Syst. Sci., 15, 247–259, https://doi.org/10.5194/nhess-15-247-2015, https://doi.org/10.5194/nhess-15-247-2015, 2015
Short summary
Short summary
Deciphering coseismic offsets from creeping is a key point for an active fault behavior. In a subaqueous setting, coseismic offsets of the seafloor may be sealed off by earthquake-triggered sediments. Along the limit of a pull-apart basin in the Sea of Marmara, successive vertical offsets (up to 1.4m) are deduced from the thicknesses of homogenites which seal-off created scarps. During a 2kyr period, coseismic seafloor offsets are dominant, representing potential tsunami hazards.
P. Brandt, H. W. Bange, D. Banyte, M. Dengler, S.-H. Didwischus, T. Fischer, R. J. Greatbatch, J. Hahn, T. Kanzow, J. Karstensen, A. Körtzinger, G. Krahmann, S. Schmidtko, L. Stramma, T. Tanhua, and M. Visbeck
Biogeosciences, 12, 489–512, https://doi.org/10.5194/bg-12-489-2015, https://doi.org/10.5194/bg-12-489-2015, 2015
Short summary
Short summary
Our observational study looks at the structure of the eastern tropical North Atlantic (ETNA) oxygen minimum zone (OMZ) in comparison with the less-ventilated, eastern tropical South Pacific OMZ. We quantify the OMZ’s oxygen budget composed of consumption, advection, lateral and vertical mixing. Substantial oxygen variability is observed on interannual to multidecadal timescales. The deoxygenation of the ETNA OMZ during the last decades represents a substantial imbalance of the oxygen budget.
S. T. Lennartz, A. Lehmann, J. Herrford, F. Malien, H.-P. Hansen, H. Biester, and H. W. Bange
Biogeosciences, 11, 6323–6339, https://doi.org/10.5194/bg-11-6323-2014, https://doi.org/10.5194/bg-11-6323-2014, 2014
Short summary
Short summary
A time series of nine oceanic parameters from the coastal time series station Boknis Eck (BE, southwestern Baltic Sea) in the period of 1957-2013 is analysed with respect to seasonal cycles and long-term trends. Most striking was a paradoxical decreasing trend in oxygen with a simultaneous decline in eutrophication. Possible reasons for this paradox, e.g. processes related to warming temperatures such as increased decomposition of organic matter or altered ventilation, are discussed.
E. V. Stanev, Y. He, J. Staneva, and E. Yakushev
Biogeosciences, 11, 5707–5732, https://doi.org/10.5194/bg-11-5707-2014, https://doi.org/10.5194/bg-11-5707-2014, 2014
R. V. Hiller, D. Bretscher, T. DelSontro, T. Diem, W. Eugster, R. Henneberger, S. Hobi, E. Hodson, D. Imer, M. Kreuzer, T. Künzle, L. Merbold, P. A. Niklaus, B. Rihm, A. Schellenberger, M. H. Schroth, C. J. Schubert, H. Siegrist, J. Stieger, N. Buchmann, and D. Brunner
Biogeosciences, 11, 1941–1959, https://doi.org/10.5194/bg-11-1941-2014, https://doi.org/10.5194/bg-11-1941-2014, 2014
S. Krause, P. Steeb, C. Hensen, V. Liebetrau, A. W. Dale, M. Nuzzo, and T. Treude
Biogeosciences, 11, 507–523, https://doi.org/10.5194/bg-11-507-2014, https://doi.org/10.5194/bg-11-507-2014, 2014
D. L. Arévalo-Martínez, M. Beyer, M. Krumbholz, I. Piller, A. Kock, T. Steinhoff, A. Körtzinger, and H. W. Bange
Ocean Sci., 9, 1071–1087, https://doi.org/10.5194/os-9-1071-2013, https://doi.org/10.5194/os-9-1071-2013, 2013
G. Jakobs, G. Rehder, G. Jost, K. Kießlich, M. Labrenz, and O. Schmale
Biogeosciences, 10, 7863–7875, https://doi.org/10.5194/bg-10-7863-2013, https://doi.org/10.5194/bg-10-7863-2013, 2013
L. Stramma, H. W. Bange, R. Czeschel, A. Lorenzo, and M. Frank
Biogeosciences, 10, 7293–7306, https://doi.org/10.5194/bg-10-7293-2013, https://doi.org/10.5194/bg-10-7293-2013, 2013
I.-N. Kim, K. Lee, H. W. Bange, and A. M. Macdonald
Biogeosciences, 10, 6783–6792, https://doi.org/10.5194/bg-10-6783-2013, https://doi.org/10.5194/bg-10-6783-2013, 2013
M. Magny, N. Combourieu-Nebout, J. L. de Beaulieu, V. Bout-Roumazeilles, D. Colombaroli, S. Desprat, A. Francke, S. Joannin, E. Ortu, O. Peyron, M. Revel, L. Sadori, G. Siani, M. A. Sicre, S. Samartin, A. Simonneau, W. Tinner, B. Vannière, B. Wagner, G. Zanchetta, F. Anselmetti, E. Brugiapaglia, E. Chapron, M. Debret, M. Desmet, J. Didier, L. Essallami, D. Galop, A. Gilli, J. N. Haas, N. Kallel, L. Millet, A. Stock, J. L. Turon, and S. Wirth
Clim. Past, 9, 2043–2071, https://doi.org/10.5194/cp-9-2043-2013, https://doi.org/10.5194/cp-9-2043-2013, 2013
C. A. Marandino, S. Tegtmeier, K. Krüger, C. Zindler, E. L. Atlas, F. Moore, and H. W. Bange
Atmos. Chem. Phys., 13, 8427–8437, https://doi.org/10.5194/acp-13-8427-2013, https://doi.org/10.5194/acp-13-8427-2013, 2013
K. Laß, H. W. Bange, and G. Friedrichs
Biogeosciences, 10, 5325–5334, https://doi.org/10.5194/bg-10-5325-2013, https://doi.org/10.5194/bg-10-5325-2013, 2013
L. Viktorsson, N. Ekeroth, M. Nilsson, M. Kononets, and P. O. J. Hall
Biogeosciences, 10, 3901–3916, https://doi.org/10.5194/bg-10-3901-2013, https://doi.org/10.5194/bg-10-3901-2013, 2013
K. S. Meyer, M. Bergmann, and T. Soltwedel
Biogeosciences, 10, 3479–3492, https://doi.org/10.5194/bg-10-3479-2013, https://doi.org/10.5194/bg-10-3479-2013, 2013
B. Vannière, M. Magny, S. Joannin, A. Simonneau, S. B. Wirth, Y. Hamann, E. Chapron, A. Gilli, M. Desmet, and F. S. Anselmetti
Clim. Past, 9, 1193–1209, https://doi.org/10.5194/cp-9-1193-2013, https://doi.org/10.5194/cp-9-1193-2013, 2013
E. Rybakova (Goroslavskaya), S. Galkin, M. Bergmann, T. Soltwedel, and A. Gebruk
Biogeosciences, 10, 3359–3374, https://doi.org/10.5194/bg-10-3359-2013, https://doi.org/10.5194/bg-10-3359-2013, 2013
C. Zindler, A. Bracher, C. A. Marandino, B. Taylor, E. Torrecilla, A. Kock, and H. W. Bange
Biogeosciences, 10, 3297–3311, https://doi.org/10.5194/bg-10-3297-2013, https://doi.org/10.5194/bg-10-3297-2013, 2013
M. R. Cunha, C. F. Rodrigues, L. Génio, A. Hilário, A. Ravara, and O. Pfannkuche
Biogeosciences, 10, 2553–2568, https://doi.org/10.5194/bg-10-2553-2013, https://doi.org/10.5194/bg-10-2553-2013, 2013
S. Joannin, B. Vannière, D. Galop, O. Peyron, J. N. Haas, A. Gilli, E. Chapron, S. B. Wirth, F. Anselmetti, M. Desmet, and M. Magny
Clim. Past, 9, 913–933, https://doi.org/10.5194/cp-9-913-2013, https://doi.org/10.5194/cp-9-913-2013, 2013
A. Simonneau, E. Chapron, B. Vannière, S. B. Wirth, A. Gilli, C. Di Giovanni, F. S. Anselmetti, M. Desmet, and M. Magny
Clim. Past, 9, 825–840, https://doi.org/10.5194/cp-9-825-2013, https://doi.org/10.5194/cp-9-825-2013, 2013
V. J. Bertics, C. R. Löscher, I. Salonen, A. W. Dale, J. Gier, R. A. Schmitz, and T. Treude
Biogeosciences, 10, 1243–1258, https://doi.org/10.5194/bg-10-1243-2013, https://doi.org/10.5194/bg-10-1243-2013, 2013
A. W. Dale, V. J. Bertics, T. Treude, S. Sommer, and K. Wallmann
Biogeosciences, 10, 629–651, https://doi.org/10.5194/bg-10-629-2013, https://doi.org/10.5194/bg-10-629-2013, 2013
W. Gülzow, G. Rehder, J. Schneider v. Deimling, T. Seifert, and Z. Tóth
Biogeosciences, 10, 81–99, https://doi.org/10.5194/bg-10-81-2013, https://doi.org/10.5194/bg-10-81-2013, 2013
S. Naeher, M. Geraga, G. Papatheodorou, G. Ferentinos, H. Kaberi, and C. J. Schubert
Biogeosciences, 9, 5081–5094, https://doi.org/10.5194/bg-9-5081-2012, https://doi.org/10.5194/bg-9-5081-2012, 2012
P. Pop Ristova, F. Wenzhöfer, A. Ramette, M. Zabel, D. Fischer, S. Kasten, and A. Boetius
Biogeosciences, 9, 5031–5048, https://doi.org/10.5194/bg-9-5031-2012, https://doi.org/10.5194/bg-9-5031-2012, 2012
L. M. Zamora, A. Oschlies, H. W. Bange, K. B. Huebert, J. D. Craig, A. Kock, and C. R. Löscher
Biogeosciences, 9, 5007–5022, https://doi.org/10.5194/bg-9-5007-2012, https://doi.org/10.5194/bg-9-5007-2012, 2012
Related subject area
Biogeochemistry: Coastal Ocean
Effects of submarine groundwater on nutrient concentration and primary production in a deep bay of the Japan Sea
The bacteria–protist link as a main route of dissolved organic matter across contrasting productivity areas on the Patagonian Shelf
Ocean alkalinity enhancement (OAE) does not cause cellular stress in a phytoplankton community of the subtropical Atlantic Ocean
Reviews and syntheses: On increasing hypoxia in eastern boundary upwelling systems – zooplankton under metabolic stress
Technical note: Testing a new approach for the determination of N2 fixation rates by coupling a membrane equilibrator to a mass spectrometer for long-term observations
Long-term variations in pH in coastal waters along the Korean Peninsula
The effect of carbonate mineral additions on biogeochemical conditions in surface sediments and benthic–pelagic exchange fluxes
Evaluating ocean alkalinity enhancement as a carbon dioxide removal strategy in the North Sea
Assessing the impacts of simulated ocean alkalinity enhancement on viability and growth of nearshore species of phytoplankton
Responses of microbial metabolic rates to non-equilibrated silicate- versus calcium-based ocean alkalinity enhancement
High metabolic zinc demand within native Amundsen and Ross sea phytoplankton communities determined by stable isotope uptake rate measurements
The influence of zooplankton and oxygen on the particulate organic carbon flux in the Benguela Upwelling System
Reviews and syntheses: Biological indicators of low-oxygen stress in marine water-breathing animals
Temperature-enhanced effects of iron on Southern Ocean phytoplankton
Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth system model
The Northeast Greenland Shelf as a potential late-summer CO2 source to the atmosphere
Spring-neap tidal cycles modulate the strength of the carbon source at the estuary-coast interface
Technical note: Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project (OAEPIIP)
Estimates of carbon sequestration potential in an expanding Arctic fjord (Hornsund, Svalbard) affected by dark plumes of glacial meltwater
An assessment of ocean alkalinity enhancement using aqueous hydroxides: kinetics, efficiency, and precipitation thresholds
Dissolved nitric oxide in the lower Elbe Estuary and the Port of Hamburg area
Variable contribution of wastewater treatment plant effluents to downstream nitrous oxide concentrations and emissions
Depositional controls and budget of organic carbon burial in fine-grained sediments of the North Sea – the Helgoland Mud Area as a test field
Improved understanding of eutrophication trends, indicators and problem areas using machine learning
Distribution of nutrients and dissolved organic matter in a eutrophic equatorial estuary: the Johor River and the East Johor Strait
Amplified bottom water acidification rates on the Bering Sea shelf from 1970–2022
Investigating the effect of silicate- and calcium-based ocean alkalinity enhancement on diatom silicification
Ocean alkalinity enhancement using sodium carbonate salts does not lead to measurable changes in Fe dynamics in a mesocosm experiment
Quantification and mitigation of bottom-trawling impacts on sedimentary organic carbon stocks in the North Sea
Influence of ocean alkalinity enhancement with olivine or steel slag on a coastal plankton community in Tasmania
Multi-model comparison of trends and controls of near-bed oxygen concentration on the northwest European continental shelf under climate change
Picoplanktonic methane production in eutrophic surface waters
Vertical mixing alleviates autumnal oxygen deficiency in the central North Sea
Hypoxia also occurs in small highly turbid estuaries: the example of the Charente (Bay of Biscay)
Seasonality and response of ocean acidification and hypoxia to major environmental anomalies in the southern Salish Sea, North America (2014–2018)
Oceanographic processes driving low-oxygen conditions inside Patagonian fjords
Above- and belowground plant mercury dynamics in a salt marsh estuary in Massachusetts, USA
Variability and drivers of carbonate chemistry at shellfish aquaculture sites in the Salish Sea, British Columbia
Unusual Hemiaulus bloom influences ocean productivity in Northeastern US Shelf waters
Insights into carbonate environmental conditions in the Chukchi Sea
UAV approaches for improved mapping of vegetation cover and estimation of carbon storage of small saltmarshes: examples from Loch Fleet, northeast Scotland
Iron “ore” nothing: benthic iron fluxes from the oxygen-deficient Santa Barbara Basin enhance phytoplankton productivity in surface waters
Marine anoxia initiates giant sulfur-oxidizing bacterial mat proliferation and associated changes in benthic nitrogen, sulfur, and iron cycling in the Santa Barbara Basin, California Borderland
Uncertainty in the evolution of northwestern North Atlantic circulation leads to diverging biogeochemical projections
The additionality problem of ocean alkalinity enhancement
Short-term variation in pH in seawaters around coastal areas of Japan: characteristics and forcings
Revisiting the applicability and constraints of molybdenum- and uranium-based paleo redox proxies: comparing two contrasting sill fjords
Influence of a small submarine canyon on biogenic matter export flux in the lower St. Lawrence Estuary, eastern Canada
Single-celled bioturbators: benthic foraminifera mediate oxygen penetration and prokaryotic diversity in intertidal sediment
Assessing impacts of coastal warming, acidification, and deoxygenation on Pacific oyster (Crassostrea gigas) farming: a case study in the Hinase area, Okayama Prefecture, and Shizugawa Bay, Miyagi Prefecture, Japan
Menghong Dong, Xinyu Guo, Takuya Matsuura, Taichi Tebakari, and Jing Zhang
Biogeosciences, 22, 2383–2402, https://doi.org/10.5194/bg-22-2383-2025, https://doi.org/10.5194/bg-22-2383-2025, 2025
Short summary
Short summary
Submarine groundwater discharge (SGD), a common coastal hydrological process that involves submarine inflow of groundwater into the sea, is associated with a large nutrient load. To clarify the distribution of SGD-derived nutrients after release at the bottom of the sea and their contribution to phytoplankton growth in the marine ecosystem, we modeled the SGD process in Toyama Bay using a specialized computer code that can distinguish SGD-derived nutrients from nutrients from other sources.
M. Celeste López-Abbate, John E. Garzón-Cardona, Ricardo Silva, Juan-Carlos Molinero, Laura A. Ruiz-Etcheverry, Ana M. Martínez, Azul S. Gilabert, and Rubén J. Lara
Biogeosciences, 22, 2309–2325, https://doi.org/10.5194/bg-22-2309-2025, https://doi.org/10.5194/bg-22-2309-2025, 2025
Short summary
Short summary
This study explores how microbial dynamics influence the dissolved organic matter (DOM) pool in the Patagonian Shelf. Despite high phytoplankton biomass, selective grazing on fast-growing bacteria led to DOM accumulation, likely due to reduced DOM-consuming bacteria and added egestion compounds. Experiments showed that bacteria not only acted as a carbon sink through mineralization but also transferred assimilated carbon dioxide (CO2) to higher trophic levels.
Librada Ramírez, Leonardo J. Pozzo-Pirotta, Aja Trebec, Víctor Manzanares-Vázquez, José L. Díez, Javier Arístegui, Ulf Riebesell, Stephen D. Archer, and María Segovia
Biogeosciences, 22, 1865–1886, https://doi.org/10.5194/bg-22-1865-2025, https://doi.org/10.5194/bg-22-1865-2025, 2025
Short summary
Short summary
We studied the potential effects of increasing ocean alkalinity on a natural plankton community in subtropical waters of the Atlantic near Gran Canaria, Spain. Alkalinity is the capacity of water to resist acidification, and plankton are usually microscopic plants (phytoplankton) and animals (zooplankton), often less than 2.5 cm in length. This study suggests that increasing ocean alkalinity did not have a significant negative impact on the plankton community studied.
Leissing Frederick, Mauricio A. Urbina, and Ruben Escribano
Biogeosciences, 22, 1839–1852, https://doi.org/10.5194/bg-22-1839-2025, https://doi.org/10.5194/bg-22-1839-2025, 2025
Short summary
Short summary
Evidence shows that due to global warming, zooplankton inhabiting the coastal upwelling zone are exposed to increasing hypoxia affecting their physiology, metabolism, and population dynamics. The adaptive responses of zooplankton to cope with mild/severe hypoxia may depend on trade-offs with other metabolic/energy demands, implying less energy for growth, feeding, and reproduction, with ecological consequences for the zooplankton population and the marine food web.
Sören Iwe, Oliver Schmale, and Bernd Schneider
Biogeosciences, 22, 1767–1779, https://doi.org/10.5194/bg-22-1767-2025, https://doi.org/10.5194/bg-22-1767-2025, 2025
Short summary
Short summary
We present a novel method for quantifying N2 fixation by cyanobacteria, which is crucial in Baltic Sea eutrophication. Our Gas Equilibrium – Membrane-Inlet Mass Spectrometer (GE-MIMS), designed for operation on voluntary observing ships (VOSs), enables large-scale monitoring of surface water N2 depletion caused by N2 fixation. Laboratory tests confirm the device’s accuracy and precision, ensuring that it can complement current methods and contribute valuable data for better understanding N2 fixation in the Baltic Sea.
Yong-Woo Lee, Mi-Ok Park, Seong-Gil Kim, Tae-Hoon Kim, Yong Hwa Oh, Sang Heon Lee, and DongJoo Joung
Biogeosciences, 22, 675–690, https://doi.org/10.5194/bg-22-675-2025, https://doi.org/10.5194/bg-22-675-2025, 2025
Short summary
Short summary
Long-term pH variation in coastal waters along the Korean Peninsula was assessed for the first time, and it exhibited no significant pH change over an 11-year period. This contrasts with the ongoing pH decline in open oceans and other coastal areas. Analysis of environmental data showed that pH is mainly controlled by dissolved oxygen in bottom waters. This suggests that ocean warming could cause a pH decline in Korean coastal waters, affecting many fish and seaweed aquaculture operations.
Kadir Biçe, Tristen Myers Stewart, George G. Waldbusser, and Christof Meile
Biogeosciences, 22, 641–657, https://doi.org/10.5194/bg-22-641-2025, https://doi.org/10.5194/bg-22-641-2025, 2025
Short summary
Short summary
We studied the effect of addition of carbonate minerals on coastal sediments. We carried out laboratory experiments to quantify the dissolution kinetics and integrated these observations into a numerical model that describes biogeochemical cycling in surficial sediments. Using the model, we demonstrate the buffering effect of the mineral additions and their duration. We quantify the effect under different environmental conditions and assess the potential for increased atmospheric CO2 uptake.
Feifei Liu, Ute Daewel, Jan Kossack, Kubilay Timur Demir, Helmuth Thomas, and Corinna Schrum
EGUsphere, https://doi.org/10.5194/egusphere-2025-81, https://doi.org/10.5194/egusphere-2025-81, 2025
Short summary
Short summary
Ocean Alkalinity Enhancement boosts oceanic CO₂ absorption, offering a climate solution. Using a regional model, we examined OAE in the North Sea, revealing that shallow coastal areas achieve higher CO₂ uptake than offshore, where alkalinity is more susceptible to deep-ocean loss. Long-term carbon storage is limited, and pH shifts vary by location. Our findings guide OAE deployment to optimize carbon removal while minimizing ecological effects, supporting global climate mitigation efforts.
Jessica L. Oberlander, Mackenzie E. Burke, Cat A. London, and Hugh L. MacIntyre
Biogeosciences, 22, 499–512, https://doi.org/10.5194/bg-22-499-2025, https://doi.org/10.5194/bg-22-499-2025, 2025
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a promising negative emission technology that results in the net sequestration of atmospheric carbon. In this paper, we assess the potential impact of OAE on phytoplankton through an analysis of prior studies and the effects of simulated OAE on photosynthetic competence. Our findings suggest that there may be little if any significant impact on most phytoplankton studied to date if OAE is conducted in well-flushed, nearshore environments.
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, and Ulf Riebesell
Biogeosciences, 21, 5707–5724, https://doi.org/10.5194/bg-21-5707-2024, https://doi.org/10.5194/bg-21-5707-2024, 2024
Short summary
Short summary
This study exposed a natural community to two non-CO2-equilibrated ocean alkalinity enhancement (OAE) deployments using different minerals. Adding alkalinity in this manner decreases dissolved CO2, essential for photosynthesis. While photosynthesis was not suppressed, bloom formation was mildly delayed, potentially impacting marine food webs. The study emphasizes the need for further research on OAE without prior equilibration and on its ecological implications.
Riss M. Kell, Rebecca J. Chmiel, Deepa Rao, Dawn M. Moran, Matthew R. McIlvin, Tristan J. Horner, Nicole L. Schanke, Ichiko Sugiyama, Robert B. Dunbar, Giacomo R. DiTullio, and Mak A. Saito
Biogeosciences, 21, 5685–5706, https://doi.org/10.5194/bg-21-5685-2024, https://doi.org/10.5194/bg-21-5685-2024, 2024
Short summary
Short summary
Despite interest in modeling the biogeochemical uptake and cycling of the trace metal zinc (Zn), measurements of Zn uptake in natural marine phytoplankton communities have not been conducted previously. To fill this gap, we employed a stable isotope uptake rate measurement method to quantify Zn uptake into natural phytoplankton assemblages within the Southern Ocean. Zn demand was high and rapid enough to depress the inventory of Zn available to phytoplankton on seasonal timescales.
Luisa Chiara Meiritz, Tim Rixen, Anja Karin van der Plas, Tarron Lamont, and Niko Lahajnar
Biogeosciences, 21, 5261–5276, https://doi.org/10.5194/bg-21-5261-2024, https://doi.org/10.5194/bg-21-5261-2024, 2024
Short summary
Short summary
Moored and drifting sediment trap experiments in the northern (nBUS) and southern (sBUS) Benguela Upwelling System showed that active carbon fluxes by vertically migrating zooplankton were about 3 times higher in the sBUS than in the nBUS. Despite these large variabilities, the mean passive particulate organic carbon (POC) fluxes were almost equal in the two subsystems. The more intense near-bottom oxygen minimum layer seems to lead to higher POC fluxes and accumulation rates in the nBUS.
Michael R. Roman, Andrew H. Altieri, Denise Breitburg, Erica M. Ferrer, Natalya D. Gallo, Shin-ichi Ito, Karin Limburg, Kenneth Rose, Moriaki Yasuhara, and Lisa A. Levin
Biogeosciences, 21, 4975–5004, https://doi.org/10.5194/bg-21-4975-2024, https://doi.org/10.5194/bg-21-4975-2024, 2024
Short summary
Short summary
Oxygen-depleted ocean waters have increased worldwide. In order to improve our understanding of the impacts of this oxygen loss on marine life it is essential that we develop reliable indicators that track the negative impacts of low oxygen. We review various indicators of low-oxygen stress for marine animals including their use, research needs, and application to confront the challenges of ocean oxygen loss.
Charlotte Eich, Mathijs van Manen, J. Scott P. McCain, Loay J. Jabre, Willem H. van de Poll, Jinyoung Jung, Sven B. E. H. Pont, Hung-An Tian, Indah Ardiningsih, Gert-Jan Reichart, Erin M. Bertrand, Corina P. D. Brussaard, and Rob Middag
Biogeosciences, 21, 4637–4663, https://doi.org/10.5194/bg-21-4637-2024, https://doi.org/10.5194/bg-21-4637-2024, 2024
Short summary
Short summary
Phytoplankton growth in the Southern Ocean (SO) is often limited by low iron (Fe) concentrations. Sea surface warming impacts Fe availability and can affect phytoplankton growth. We used shipboard Fe clean incubations to test how changes in Fe and temperature affect SO phytoplankton. Their abundances usually increased with Fe addition and temperature increase, with Fe being the major factor. These findings imply potential shifts in ecosystem structure, impacting food webs and elemental cycling.
Miriam Tivig, David P. Keller, and Andreas Oschlies
Biogeosciences, 21, 4469–4493, https://doi.org/10.5194/bg-21-4469-2024, https://doi.org/10.5194/bg-21-4469-2024, 2024
Short summary
Short summary
Marine biological production is highly dependent on the availability of nitrogen and phosphorus. Rivers are the main source of phosphorus to the oceans but poorly represented in global model oceans. We include dissolved nitrogen and phosphorus from river export in a global model ocean and find that the addition of riverine phosphorus affects marine biology on millennial timescales more than riverine nitrogen alone. Globally, riverine phosphorus input increases primary production rates.
Esdoorn Willcox, Marcos Lemes, Thomas Juul-Pedersen, Mikael Kristian Sejr, Johnna Marchiano Holding, and Søren Rysgaard
Biogeosciences, 21, 4037–4050, https://doi.org/10.5194/bg-21-4037-2024, https://doi.org/10.5194/bg-21-4037-2024, 2024
Short summary
Short summary
In this work, we measured the chemistry of seawater from samples obtained from different depths and locations off the east coast of the Northeast Greenland National Park to determine what is influencing concentrations of dissolved CO2. Historically, the region has always been thought to take up CO2 from the atmosphere, but we show that it is possible for the region to become a source in late summer. We discuss the variables that may be related to such changes.
Vlad A. Macovei, Louise C. V. Rewrie, Rüdiger Röttgers, and Yoana G. Voynova
EGUsphere, https://doi.org/10.5194/egusphere-2024-2643, https://doi.org/10.5194/egusphere-2024-2643, 2024
Short summary
Short summary
A commercial vessel equipped with scientific instruments regularly travelled between two large macro-tidal estuaries. We found that biogeochemical variability in the outer estuaries is driven by the 14-day spring-neap tidal cycle, with strong effects on dissolved inorganic and organic carbon concentrations and distribution. Since this land-sea interface effect increases the strength of the carbon source to the atmosphere by 74 % during spring tide, it should be accounted for in regional models.
Lennart Thomas Bach, Aaron James Ferderer, Julie LaRoche, and Kai Georg Schulz
Biogeosciences, 21, 3665–3676, https://doi.org/10.5194/bg-21-3665-2024, https://doi.org/10.5194/bg-21-3665-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is an emerging marine CO2 removal method, but its environmental effects are insufficiently understood. The OAE Pelagic Impact Intercomparison Project (OAEPIIP) provides funding for a standardized and globally replicated microcosm experiment to study the effects of OAE on plankton communities. Here, we provide a detailed manual for the OAEPIIP experiment. We expect OAEPIIP to help build scientific consensus on the effects of OAE on plankton.
Marlena Szeligowska, Déborah Benkort, Anna Przyborska, Mateusz Moskalik, Bernabé Moreno, Emilia Trudnowska, and Katarzyna Błachowiak-Samołyk
Biogeosciences, 21, 3617–3639, https://doi.org/10.5194/bg-21-3617-2024, https://doi.org/10.5194/bg-21-3617-2024, 2024
Short summary
Short summary
The European Arctic is experiencing rapid regional warming, causing glaciers that terminate in the sea to retreat onto land. Due to this process, the area of a well-studied fjord, Hornsund, has increased by around 100 km2 (40%) since 1976. Combining satellite and in situ data with a mathematical model, we estimated that, despite some negative consequences of glacial meltwater release, such emerging coastal waters could mitigate climate change by increasing carbon uptake and storage by sediments.
Mallory C. Ringham, Nathan Hirtle, Cody Shaw, Xi Lu, Julian Herndon, Brendan R. Carter, and Matthew D. Eisaman
Biogeosciences, 21, 3551–3570, https://doi.org/10.5194/bg-21-3551-2024, https://doi.org/10.5194/bg-21-3551-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement leverages the large surface area and carbon storage capacity of the oceans to store atmospheric CO2 as dissolved bicarbonate. We monitored CO2 uptake in seawater treated with NaOH to establish operational boundaries for carbon removal experiments. Results show that CO2 equilibration occurred on the order of weeks to months, was consistent with values expected from equilibration calculations, and was limited by mineral precipitation at high pH and CaCO3 saturation.
Riel Carlo O. Ingeniero, Gesa Schulz, and Hermann W. Bange
Biogeosciences, 21, 3425–3440, https://doi.org/10.5194/bg-21-3425-2024, https://doi.org/10.5194/bg-21-3425-2024, 2024
Short summary
Short summary
Our research is the first to measure dissolved NO concentrations in temperate estuarine waters, providing insights into its distribution under varying conditions and enhancing our understanding of its production processes. Dissolved NO was supersaturated in the Elbe Estuary, indicating that it is a source of atmospheric NO. The observed distribution of dissolved NO most likely resulted from nitrification.
Weiyi Tang, Jeff Talbott, Timothy Jones, and Bess B. Ward
Biogeosciences, 21, 3239–3250, https://doi.org/10.5194/bg-21-3239-2024, https://doi.org/10.5194/bg-21-3239-2024, 2024
Short summary
Short summary
Wastewater treatment plants (WWTPs) are known to be hotspots of greenhouse gas emissions. However, the impact of WWTPs on the emission of the greenhouse gas N2O in downstream aquatic environments is less constrained. We found spatially and temporally variable but overall higher N2O concentrations and fluxes in waters downstream of WWTPs, pointing to the need for efficient N2O removal in addition to the treatment of nitrogen in WWTPs.
Daniel Müller, Bo Liu, Walter Geibert, Moritz Holtappels, Lasse Sander, Elda Miramontes, Heidi Taubner, Susann Henkel, Kai-Uwe Hinrichs, Denise Bethke, Ingrid Dohrmann, and Sabine Kasten
EGUsphere, https://doi.org/10.5194/egusphere-2024-1632, https://doi.org/10.5194/egusphere-2024-1632, 2024
Short summary
Short summary
Coastal and shelf sediments are the most important sinks for organic carbon (OC) on Earth. We produced a new high-resolution sediment and pore-water dataset from the Helgoland Mud Area (HMA), North Sea, to determine, which depositional factors control the preservation of OC. The burial efficiency is highest in an area of high sedimentation and terrigenous OC. The HMA covers 0.09 % of the North Sea, but accounts for 0.76 % of its OC accumulation, highlighting the importance of the depocentre.
Deep S. Banerjee and Jozef Skakala
EGUsphere, https://doi.org/10.22541/essoar.171405637.76928549/v1, https://doi.org/10.22541/essoar.171405637.76928549/v1, 2024
Short summary
Short summary
Nitrate is a crucial nutrient in oceans. Excess nutrients can trigger uncontrolled algae growth (eutrophication), damaging marine ecosystems. We used a machine learning tool to generate a skilled, gap-free, bi-decadal surface nitrate dataset from sparse observations. This dataset reveals areas on the North West European Shelf at risk of eutrophication, bi-decadal trends in coastal nitrate, and an impact of winter nitrate on spring phytoplankton blooms.
Amanda Y. L. Cheong, Kogila Vani Annammala, Ee Ling Yong, Yongli Zhou, Robert S. Nichols, and Patrick Martin
Biogeosciences, 21, 2955–2971, https://doi.org/10.5194/bg-21-2955-2024, https://doi.org/10.5194/bg-21-2955-2024, 2024
Short summary
Short summary
We measured nutrients and dissolved organic matter for 1 year in a eutrophic tropical estuary to understand their sources and cycling. Our data show that the dissolved organic matter originates partly from land and partly from microbial processes in the water. Internal recycling is likely important for maintaining high nutrient concentrations, and we found that there is often excess nitrogen compared to silicon and phosphorus. Our data help to explain how eutrophication persists in this system.
Darren Pilcher, Jessica Cross, Natalie Monacci, Linquan Mu, Kelly Kearney, Albert Hermann, and Wei Cheng
EGUsphere, https://doi.org/10.5194/egusphere-2024-1096, https://doi.org/10.5194/egusphere-2024-1096, 2024
Short summary
Short summary
The Bering Sea shelf is a highly productive marine ecosystem that is vulnerable to ocean acidification. We use a computational model to simulate the carbon cycle and acidification rates from 1970–2022. The results suggest that bottom water acidification rates are more than twice as great as surface rates. Bottom waters are also naturally more acidic, thus these waters will pass key thresholds known to negatively impact marine organisms, such as red king crab, much sooner than surface waters.
Aaron Ferderer, Kai G. Schulz, Ulf Riebesell, Kirralee G. Baker, Zanna Chase, and Lennart T. Bach
Biogeosciences, 21, 2777–2794, https://doi.org/10.5194/bg-21-2777-2024, https://doi.org/10.5194/bg-21-2777-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a promising method of atmospheric carbon removal; however, its ecological impacts remain largely unknown. We assessed the effects of simulated silicate- and calcium-based mineral OAE on diatom silicification. We found that increased silicate concentrations from silicate-based OAE increased diatom silicification. In contrast, the enhancement of alkalinity had no effect on community silicification and minimal effects on the silicification of different genera.
David González-Santana, María Segovia, Melchor González-Dávila, Librada Ramírez, Aridane G. González, Leonardo J. Pozzo-Pirotta, Veronica Arnone, Victor Vázquez, Ulf Riebesell, and J. Magdalena Santana-Casiano
Biogeosciences, 21, 2705–2715, https://doi.org/10.5194/bg-21-2705-2024, https://doi.org/10.5194/bg-21-2705-2024, 2024
Short summary
Short summary
In a recent experiment off the coast of Gran Canaria (Spain), scientists explored a method called ocean alkalinization enhancement (OAE), where carbonate minerals were added to seawater. This process changed the levels of certain ions in the water, affecting its pH and buffering capacity. The researchers were particularly interested in how this could impact the levels of essential trace metals in the water.
Lucas Porz, Wenyan Zhang, Nils Christiansen, Jan Kossack, Ute Daewel, and Corinna Schrum
Biogeosciences, 21, 2547–2570, https://doi.org/10.5194/bg-21-2547-2024, https://doi.org/10.5194/bg-21-2547-2024, 2024
Short summary
Short summary
Seafloor sediments store a large amount of carbon, helping to naturally regulate Earth's climate. If disturbed, some sediment particles can turn into CO2, but this effect is not well understood. Using computer simulations, we found that bottom-contacting fishing gears release about 1 million tons of CO2 per year in the North Sea, one of the most heavily fished regions globally. We show how protecting certain areas could reduce these emissions while also benefitting seafloor-living animals.
Jiaying A. Guo, Robert F. Strzepek, Kerrie M. Swadling, Ashley T. Townsend, and Lennart T. Bach
Biogeosciences, 21, 2335–2354, https://doi.org/10.5194/bg-21-2335-2024, https://doi.org/10.5194/bg-21-2335-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement aims to increase atmospheric CO2 sequestration by adding alkaline materials to the ocean. We assessed the environmental effects of olivine and steel slag powder on coastal plankton. Overall, slag is more efficient than olivine in releasing total alkalinity and, thus, in its ability to sequester CO2. Slag also had less environmental effect on the enclosed plankton communities when considering its higher CO2 removal potential based on this 3-week experiment.
Giovanni Galli, Sarah Wakelin, James Harle, Jason Holt, and Yuri Artioli
Biogeosciences, 21, 2143–2158, https://doi.org/10.5194/bg-21-2143-2024, https://doi.org/10.5194/bg-21-2143-2024, 2024
Short summary
Short summary
This work shows that, under a high-emission scenario, oxygen concentration in deep water of parts of the North Sea and Celtic Sea can become critically low (hypoxia) towards the end of this century. The extent and frequency of hypoxia depends on the intensity of climate change projected by different climate models. This is the result of a complex combination of factors like warming, increase in stratification, changes in the currents and changes in biological processes.
Sandy E. Tenorio and Laura Farías
Biogeosciences, 21, 2029–2050, https://doi.org/10.5194/bg-21-2029-2024, https://doi.org/10.5194/bg-21-2029-2024, 2024
Short summary
Short summary
Time series studies show that CH4 is highly dynamic on the coastal ocean surface and planktonic communities are linked to CH4 accumulation, as found in coastal upwelling off Chile. We have identified the crucial role of picoplankton (> 3 µm) in CH4 recycling, especially with the addition of methylated substrates (trimethylamine and methylphosphonic acid) during upwelling and non-upwelling periods. These insights improve understanding of surface ocean CH4 recycling, aiding CH4 emission estimates.
Charlotte A. J. Williams, Tom Hull, Jan Kaiser, Claire Mahaffey, Naomi Greenwood, Matthew Toberman, and Matthew R. Palmer
Biogeosciences, 21, 1961–1971, https://doi.org/10.5194/bg-21-1961-2024, https://doi.org/10.5194/bg-21-1961-2024, 2024
Short summary
Short summary
Oxygen (O2) is a key indicator of ocean health. The risk of O2 loss in the productive coastal/continental slope regions is increasing. Autonomous underwater vehicles equipped with O2 optodes provide lots of data but have problems resolving strong vertical O2 changes. Here we show how to overcome this and calculate how much O2 is supplied to the low-O2 bottom waters via mixing. Bursts in mixing supply nearly all of the O2 to bottom waters in autumn, stopping them reaching ecologically low levels.
Sabine Schmidt and Ibrahima Iris Diallo
Biogeosciences, 21, 1785–1800, https://doi.org/10.5194/bg-21-1785-2024, https://doi.org/10.5194/bg-21-1785-2024, 2024
Short summary
Short summary
Along the French coast facing the Bay of Biscay, the large Gironde and Loire estuaries suffer from hypoxia. This prompted a study of the small Charente estuary located between them. This work reveals a minimum oxygen zone in the Charente estuary, which extends for about 25 km. Temperature is the main factor controlling the hypoxia. This calls for the monitoring of small turbid macrotidal estuaries that are vulnerable to hypoxia, a risk expected to increase with global warming.
Simone R. Alin, Jan A. Newton, Richard A. Feely, Samantha Siedlecki, and Dana Greeley
Biogeosciences, 21, 1639–1673, https://doi.org/10.5194/bg-21-1639-2024, https://doi.org/10.5194/bg-21-1639-2024, 2024
Short summary
Short summary
We provide a new multi-stressor data product that allows us to characterize the seasonality of temperature, O2, and CO2 in the southern Salish Sea and delivers insights into the impacts of major marine heatwave and precipitation anomalies on regional ocean acidification and hypoxia. We also describe the present-day frequencies of temperature, O2, and ocean acidification conditions that cross thresholds of sensitive regional species that are economically or ecologically important.
Pamela Linford, Iván Pérez-Santos, Paulina Montero, Patricio A. Díaz, Claudia Aracena, Elías Pinilla, Facundo Barrera, Manuel Castillo, Aida Alvera-Azcárate, Mónica Alvarado, Gabriel Soto, Cécile Pujol, Camila Schwerter, Sara Arenas-Uribe, Pilar Navarro, Guido Mancilla-Gutiérrez, Robinson Altamirano, Javiera San Martín, and Camila Soto-Riquelme
Biogeosciences, 21, 1433–1459, https://doi.org/10.5194/bg-21-1433-2024, https://doi.org/10.5194/bg-21-1433-2024, 2024
Short summary
Short summary
The Patagonian fjords comprise a world region where low-oxygen water and hypoxia conditions are observed. An in situ dataset was used to quantify the mechanism involved in the presence of these conditions in northern Patagonian fjords. Water mass analysis confirmed the contribution of Equatorial Subsurface Water in the advection of the low-oxygen water, and hypoxic conditions occurred when the community respiration rate exceeded the gross primary production.
Ting Wang, Buyun Du, Inke Forbrich, Jun Zhou, Joshua Polen, Elsie M. Sunderland, Prentiss H. Balcom, Celia Chen, and Daniel Obrist
Biogeosciences, 21, 1461–1476, https://doi.org/10.5194/bg-21-1461-2024, https://doi.org/10.5194/bg-21-1461-2024, 2024
Short summary
Short summary
The strong seasonal increases of Hg in aboveground biomass during the growing season and the lack of changes observed after senescence in this salt marsh ecosystem suggest physiologically controlled Hg uptake pathways. The Hg sources found in marsh aboveground tissues originate from a mix of sources, unlike terrestrial ecosystems, where atmospheric GEM is the main source. Belowground plant tissues mostly take up Hg from soils. Overall, the salt marsh currently serves as a small net Hg sink.
Eleanor Simpson, Debby Ianson, Karen E. Kohfeld, Ana C. Franco, Paul A. Covert, Marty Davelaar, and Yves Perreault
Biogeosciences, 21, 1323–1353, https://doi.org/10.5194/bg-21-1323-2024, https://doi.org/10.5194/bg-21-1323-2024, 2024
Short summary
Short summary
Shellfish aquaculture operates in nearshore areas where data on ocean acidification parameters are limited. We show daily and seasonal variability in pH and saturation states of calcium carbonate at nearshore aquaculture sites in British Columbia, Canada, and determine the contributing drivers of this variability. We find that nearshore locations have greater variability than open waters and that the uptake of carbon by phytoplankton is the major driver of pH and saturation state variability.
S. Alejandra Castillo Cieza, Rachel H. R. Stanley, Pierre Marrec, Diana N. Fontaine, E. Taylor Crockford, Dennis J. McGillicuddy Jr., Arshia Mehta, Susanne Menden-Deuer, Emily E. Peacock, Tatiana A. Rynearson, Zoe O. Sandwith, Weifeng Zhang, and Heidi M. Sosik
Biogeosciences, 21, 1235–1257, https://doi.org/10.5194/bg-21-1235-2024, https://doi.org/10.5194/bg-21-1235-2024, 2024
Short summary
Short summary
The coastal ocean in the northeastern USA provides many services, including fisheries and habitats for threatened species. In summer 2019, a bloom occurred of a large unusual phytoplankton, the diatom Hemiaulus, with nitrogen-fixing symbionts. This led to vast changes in productivity and grazing rates in the ecosystem. This work shows that the emergence of one species can have profound effects on ecosystem function. Such changes may become more prevalent as the ocean warms due to climate change.
Claudine Hauri, Brita Irving, Sam Dupont, Rémi Pagés, Donna D. W. Hauser, and Seth L. Danielson
Biogeosciences, 21, 1135–1159, https://doi.org/10.5194/bg-21-1135-2024, https://doi.org/10.5194/bg-21-1135-2024, 2024
Short summary
Short summary
Arctic marine ecosystems are highly susceptible to impacts of climate change and ocean acidification. We present pH and pCO2 time series (2016–2020) from the Chukchi Ecosystem Observatory and analyze the drivers of the current conditions to get a better understanding of how climate change and ocean acidification could affect the ecological niches of organisms.
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.
De'Marcus Robinson, Anh L. D. Pham, David J. Yousavich, Felix Janssen, Frank Wenzhöfer, Eleanor C. Arrington, Kelsey M. Gosselin, Marco Sandoval-Belmar, Matthew Mar, David L. Valentine, Daniele Bianchi, and Tina Treude
Biogeosciences, 21, 773–788, https://doi.org/10.5194/bg-21-773-2024, https://doi.org/10.5194/bg-21-773-2024, 2024
Short summary
Short summary
The present study suggests that high release of ferrous iron from the seafloor of the oxygen-deficient Santa Barabara Basin (California) supports surface primary productivity, creating positive feedback on seafloor iron release by enhancing low-oxygen conditions in the basin.
David J. Yousavich, De'Marcus Robinson, Xuefeng Peng, Sebastian J. E. Krause, Frank Wenzhöfer, Felix Janssen, Na Liu, Jonathan Tarn, Franklin Kinnaman, David L. Valentine, and Tina Treude
Biogeosciences, 21, 789–809, https://doi.org/10.5194/bg-21-789-2024, https://doi.org/10.5194/bg-21-789-2024, 2024
Short summary
Short summary
Declining oxygen (O2) concentrations in coastal oceans can threaten people’s ways of life and food supplies. Here, we investigate how mats of bacteria that proliferate on the seafloor of the Santa Barbara Basin sustain and potentially worsen these O2 depletion events through their unique chemoautotrophic metabolism. Our study shows how changes in seafloor microbiology and geochemistry brought on by declining O2 concentrations can help these mats grow as well as how that growth affects the basin.
Krysten Rutherford, Katja Fennel, Lina Garcia Suarez, and Jasmin G. John
Biogeosciences, 21, 301–314, https://doi.org/10.5194/bg-21-301-2024, https://doi.org/10.5194/bg-21-301-2024, 2024
Short summary
Short summary
We downscaled two mid-century (~2075) ocean model projections to a high-resolution regional ocean model of the northwest North Atlantic (NA) shelf. In one projection, the NA shelf break current practically disappears; in the other it remains almost unchanged. This leads to a wide range of possible future shelf properties. More accurate projections of coastal circulation features would narrow the range of possible outcomes of biogeochemical projections for shelf regions.
Lennart Thomas Bach
Biogeosciences, 21, 261–277, https://doi.org/10.5194/bg-21-261-2024, https://doi.org/10.5194/bg-21-261-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a widely considered marine carbon dioxide removal method. OAE aims to accelerate chemical rock weathering, which is a natural process that slowly sequesters atmospheric carbon dioxide. This study shows that the addition of anthropogenic alkalinity via OAE can reduce the natural release of alkalinity and, therefore, reduce the efficiency of OAE for climate mitigation. However, the additionality problem could be mitigated via a variety of activities.
Tsuneo Ono, Daisuke Muraoka, Masahiro Hayashi, Makiko Yorifuji, Akihiro Dazai, Shigeyuki Omoto, Takehiro Tanaka, Tomohiro Okamura, Goh Onitsuka, Kenji Sudo, Masahiko Fujii, Ryuji Hamanoue, and Masahide Wakita
Biogeosciences, 21, 177–199, https://doi.org/10.5194/bg-21-177-2024, https://doi.org/10.5194/bg-21-177-2024, 2024
Short summary
Short summary
We carried out parallel year-round observations of pH and related parameters in five stations around the Japan coast. It was found that short-term acidified situations with Omega_ar less than 1.5 occurred at four of five stations. Most of such short-term acidified events were related to the short-term low salinity event, and the extent of short-term pH drawdown at high freshwater input was positively correlated with the nutrient concentration of the main rivers that flow into the coastal area.
K. Mareike Paul, Martijn Hermans, Sami A. Jokinen, Inda Brinkmann, Helena L. Filipsson, and Tom Jilbert
Biogeosciences, 20, 5003–5028, https://doi.org/10.5194/bg-20-5003-2023, https://doi.org/10.5194/bg-20-5003-2023, 2023
Short summary
Short summary
Seawater naturally contains trace metals such as Mo and U, which accumulate under low oxygen conditions on the seafloor. Previous studies have used sediment Mo and U contents as an archive of changing oxygen concentrations in coastal waters. Here we show that in fjords the use of Mo and U for this purpose may be impaired by additional processes. Our findings have implications for the reliable use of Mo and U to reconstruct oxygen changes in fjords.
Hannah Sharpe, Michel Gosselin, Catherine Lalande, Alexandre Normandeau, Jean-Carlos Montero-Serrano, Khouloud Baccara, Daniel Bourgault, Owen Sherwood, and Audrey Limoges
Biogeosciences, 20, 4981–5001, https://doi.org/10.5194/bg-20-4981-2023, https://doi.org/10.5194/bg-20-4981-2023, 2023
Short summary
Short summary
We studied the impact of submarine canyon processes within the Pointe-des-Monts system on biogenic matter export and phytoplankton assemblages. Using data from three oceanographic moorings, we show that the canyon experienced two low-amplitude sediment remobilization events in 2020–2021 that led to enhanced particle fluxes in the deep-water column layer > 2.6 km offshore. Sinking phytoplankton fluxes were lower near the canyon compared to background values from the lower St. Lawrence Estuary.
Dewi Langlet, Florian Mermillod-Blondin, Noémie Deldicq, Arthur Bauville, Gwendoline Duong, Lara Konecny, Mylène Hugoni, Lionel Denis, and Vincent M. P. Bouchet
Biogeosciences, 20, 4875–4891, https://doi.org/10.5194/bg-20-4875-2023, https://doi.org/10.5194/bg-20-4875-2023, 2023
Short summary
Short summary
Benthic foraminifera are single-cell marine organisms which can move in the sediment column. They were previously reported to horizontally and vertically transport sediment particles, yet the impact of their motion on the dissolved fluxes remains unknown. Using microprofiling, we show here that foraminiferal burrow formation increases the oxygen penetration depth in the sediment, leading to a change in the structure of the prokaryotic community.
Masahiko Fujii, Ryuji Hamanoue, Lawrence Patrick Cases Bernardo, Tsuneo Ono, Akihiro Dazai, Shigeyuki Oomoto, Masahide Wakita, and Takehiro Tanaka
Biogeosciences, 20, 4527–4549, https://doi.org/10.5194/bg-20-4527-2023, https://doi.org/10.5194/bg-20-4527-2023, 2023
Short summary
Short summary
This is the first study of the current and future impacts of climate change on Pacific oyster farming in Japan. Future coastal warming and acidification may affect oyster larvae as a result of longer exposure to lower-pH waters. A prolonged spawning period may harm oyster processing by shortening the shipping period and reducing oyster quality. To minimize impacts on Pacific oyster farming, in addition to mitigation measures, local adaptation measures may be required.
Cited articles
Adrian, R., O'Reilly, C. M., Zagarese, H., Baines, S. B., Hessen, D. O., Keller, W., Livingstone, D. M., Sommaruga, R., Straile, D., van Donk, E., Weyhenmeyer, G. A., and Winder, M.: Lakes as sentinels of climate change, Limnol. Oceanogr., 54, 2283–2297, 2009.
Anneville, O., Gammeter, S., and Straile, D.: Phosphorus decrease and climate variability: mediators of synchrony in phytoplankton changes among European peri-alpine lakes, Freshwater Biol., 50, 1731–1746, 2005.
Anneville, O., Souissi, S., Gammeter, S., and Straile, D.: Seasonal and inter-annual scales of variability in phytoplankton assemblages: Comparison of phytoplankton dynamics in three peri-alpine lakes over a period of28 years, Freshwater Biol., 49, 98–115, 2004.
BACC: Assessment of Climate Change in the Baltic Sea Basin, Springer, Berlin, 473 pp., 2008.
Bachmann, H.: Hydrobiologische Untersuchungen am Rotsee, Aquat. Sci., 5, 39–81, 1931.
Balzer, W., Grasshoff, K., Dieckmann, P., Haardt, H., and Petersohn, U.: Redox turnover at the sediment/water interface studied in a large bell jar system, Oceanol. Acta, 6, 337–344, 1983.
Bange, H. W., Dale, A., Hansen, H. P., Karstensen, J., Malien, F., Petereit, C., Laß, K., and Friedrichs, G.: Boknis Eck time series station (SW Baltic Sea): measurements from 1957 to 2010, LOICZ Inprint, 1, 16–22, 2011.
Beckers, J. M., Gregoire, M., Nihoul, J. C. J., Stanev, E., Staneva, J., and Lancelot, C.: Modelling the Danube-influenced north-western continental shelf of the Black Sea. I: Hydrodynamical processes simulated by 3-D and boxmodels, Estuar. Coast. Shelf S., 54, 453–472, 2002.
Begun, T., Teaca, A., and Gomoiu, M. -T.: State of macrobenthos within Modiolus phaseolinus biocoenosis from Romanian Black Sea continental shelf, GeoEcoMarina, 16, 5–18, 2010.
Bell, W. H.: The Exchange of Deep Water in Howe Sound Basin, Marine Sciences Directorate, Pacific Region Environment Canada, Report 73–13, 109 pp., 1973.
Benton, M. J.: When Life Nearly Died: The Greatest Mass Extinction of All Time, Thames & Hudson, London, 336 pp., 2005.
Bianchi, D., Galbraith, E. D., Carozza, D. A., Mislan, K. A. S., and Stock, C. A.: Intensification of open-ocean oxygen depletion by vertically migrating animals, Nat. Geosci., 6, 545–548, 2013.
Bloesch, J.: Sedimentation und Phosphorhaushalt im Vierwaldstättersee (Horwer Bucht) und im Rotsee, Aquat. Sci., 36, 71–186, 1974.
Bohlen, L., Dale, A. W., Sommer, S., Mosch, T., Hensen, C., Noffke, A., Scholz, F., and Wallmann, K.: Benthic nitrogen cycling traversing the Peruvian oxygen minimum zone, Geochimica et Cosmochimica Acta , 75, 6094–6111, 2011.
Brewer, P. G. and Peltzer, E. T.: Limits to marine life, Science, 324, 347–348, 2009.
Brocks, J. J. and Summons, R. E.: Sedimentary hydrocarbons, biomarkers for early life, in: Treatise in Geochemistry, edited by: Holland, H. D. and Turekian, K., Elsevier, 65–115, 2003.
BSC: State of the environment of the Black Sea (2001–2006/7), in: Publications of the Commission on the Protection of the Black Sea Against Pollution (BSC) 2008–3, edited by: Oguz, T., Istanbul, Turkey, 83–98, 273–320, 2008.
Canfield, D. E., Kristensen, E., and Thamdrup, B.: Aquatic geomicrobiology, Advances in Mar. Biol., 48, 1–642, 2005.
Canfield, D. E., Jørgensen, B. B., Fossing, H., Glud, R., Gundersen, J., Ramsing, N. B., Thamdrup, B., Hansen, J. W., Nielsen, L. P., and Hall, P. O. J.: Pathways of organic carbon oxidation in three continental margin sediments, Mar. Geol., 113, 27–40, 1993.
Capet, A., Beckers, J. -M., and Grégoire, M.: Drivers, mechanisms and long-term variability of seasonal hypoxia on the Black Sea northwestern shelf– is there any recovery after eutrophication?, Biogeosciences, 10, 3943–3962, https://doi.org/10.5194/bg-10-3943-2013, 2013.
Chen, C., Liu, H., and Beardsley, R. C.: An unstructured, finite volume, three-dimensional, primitive equation ocean model: application to coastal ocean and estuaries, J. Atmos. Ocean. Tech., 20, 159–186, 2003.
Cociasu, A., Dorogan, L., Humborg, C., and Popa, L.: Long-term ecological changes in Romanian coastal waters of the Black Sea, Mar. Pollut. Bull., 32, 32–38, 1996.
Conley, D. J. and Johnstone, R. W.: Biogeochemistry of N, P and Si in Baltic Sea sediments: response to a simulated deposition of a spring diatom bloom, Mar. Ecol. -Prog. Ser., 122, 265–276, 1995.
Conley, D. J., Björck, S., Bonsdorff, E., Carstensen, J., Destouni, G., Gustafsson, B. G., Hietanen, S., Kortekaas, M., Kuosa, H., Meier, H. E. M., Müller-Karulis, B., Nordberg, K., Norkko, A., Nürnberg, G., Pitknen, H., Rabalais, N. N., Rosenberg, R., Savchuk, O. P., Slomp, C. P., Voss, M., Wulff, F., and Zillen, L.: Hypoxia-related processes in the Baltic Sea, Environ. Sci. Technol., 43, 3412–3420, 2009.
Conversi, A., Umani, S. F., Peluso, T., Molinero, J. C., A., S., and Edwards, M.: The Mediterranean Sea regime shift at the end of the 1980s, and intriguing parallelisms with other European Basins, PLOS ONE, 5, e10633, https://doi.org/10.1371/journal.pone.0010633, 2010.
Cowan, J. L. W. and Boynton, W. R.: Sediment-water oxygen and nutrient exchanges along the longitudinal axis of Chesapeake Bay: seasonal patterns, controlling factors and ecological significance, Estuaries, 19, 562–580, 1996.
Dale, A. W., Bertics, V. J., Treude, T., Sommer, S., and Wallmann, K.: Modeling benthic–pelagic nutrient exchange processes and porewater distributions in a seasonally hypoxic sediment: evidence for massive phosphate release by Beggiatoa?, Biogeosciences, 10, 629–651, https://doi.org/10.5194/bg-10-629-2013, 2013.
Dassenakis, M., Krasakopoulou, E., and Matzara, B.: Chemical characteristics of Aetoliko lagoon, Greece, after an ecological shock, Mar. Pollut. Bull., 28, 427–433, 1994.
Davison, W.: Iron and manganese in lakes, Earth-Sci. Rev., 34, 119–163, 1993.
Dellwig, O., Leipe, T., März, C., Glockzin, M., Pollehne, F., Schnetger, B., Yakushev, E. V., Böttcher, M. E., and Brumsack, H. -J.: A new particulate Mn–Fe–P-shuttle at the redoxcline of anoxic basins, Geochim. Cosmochim. Ac., 74, 7100–7115, 2010.
Diaz, R. J.: Overview of Hypoxia around the World, J. Environ. Qual., 30, 275–281, 2001.
Diaz, R. J. and Rosenberg, R.: Spreading dead zones and consequences for marine ecosystems, Science, 321, 926–929, 2008.
Dimitriou, E., Rousi, A., Tasioulis, J., and Koutsikopoulos, C.: Environmental parameters record during and after an anoxic crisis in the Etoliko Lagoon (Western Greece), in: 14th Hellenic Congress of Ichthyologists, Piraeus, 2010.
Edwards, A. and Edelsten, D. J.: Deep-water renewal of Loch Etive: a three basin Scottish fjord, Estuar. Coast. Mar. Sci., 5, 575–595, 1977.
Ekau, W., Auel, H., Pörtner, H.-O., and Gilbert, D.: Impacts of hypoxia on the structure and processes in pelagic communities (zooplankton, macro-invertebrates and fish), Biogeosciences, 7, 1669–1699, https://doi.org/10.5194/bg-7-1669-2010, 2010.
Emeis, K. C., Brüchert, V., Currie, B., Endler, R., Ferdelman, T., Kiessling, A., Leipe, T., Noli-Peard, K., Struck, U., and Vogt, T.: Shallow gas in shelf sediments of the Namibian coastal upwelling ecosystem, Cont. Shelf. Res., 24, 627–642, 2004.
Etiope, G., Papatheodorou, G., Christodoulou, D., Ferentinos, G., Sokos, E., and Faval, I. P.: Methane and hydrogen sulfide seepage in the NW Peloponnesus petroliferous basin (Greece): origin and geohazard, AAPG Bull., 90, 701–713, 2006.
Etiope, G., Christodoulou, D., Kordella, S., Marinaro, G., and Papatheodorou, G.: Offshore and onshore seepage of thermogenic gas at Katakolo Bay (Western Greece), Chem. Geol., 339, 115–126, https://doi.org/10.1016/j.chemgeo.2012.08.011, 2013.
Fahrbach, E., Meincke, J., Osterhus, S., Rohardt, G., Schauer, U., Tverberg, V., and Verduin, J.: Direct measurements of volume transports through Fram Strait, Polar Res., 20, 217–224, 2001.
Feistel, R., Nausch, G., and Wasmund, N.: State and evolution of the Baltic Sea, 1952–2005, Wiley Interscience, Hoboken, NJ, USA, 703 pp., 2008.
Ferentinos, F., Papatheodorou, G., Geraga, M., Iatrou, M., Fakiris, E., Christodoulou, D., Dimitriou, E., and Koutsikopoulos, C.: Fjord water circulation and dysoxic/anoxic conditions in a Mediterranean semi-enclosed embayment in Amvrakikos Gulf, Greece, Estuar. Coast. Shelf S., 88, 473–481, 2010.
Filonov, A. E.: Thermic structure and intense internal waves on the narrow continental shelf of the Black Sea, J. Marine Syst., 24, 27–40, 2000.
Friederich, G. E., Codispoti, L. A., and Sakamoto, C. M.: Bottle and Pumpcast Data from the 1988 Black Sea Expedition Technical Report 90-3, Monterey Bay Aquarium Research Institution, Monterey, 1990.
Friedrich, J., Dinkel, C., Friedl, G., Pimenov, N., Wijsman, J., Gomoiu, M. -T., Cociasu, A., Popa, L., and Wehrli, B.: Benthic nutrient cycling and diagenetic pathways in the north-western Black Sea, Estuar. Coast. Shelf S., 54, 369–383, 2002.
Gianni, A. and Zacharias, I.: Anoxia, hydrogen sulfide and storm events in Aitoliko Lagoon, Greece, in: 3rd International CEMEPE and SECOTOX Conference, 19–24 June, Skiathos, 125–130, 2011.
Gilbert S., Gundersen, K., Johengen, T., McKissack, T., McIntyre, M., Pinchuk, A., Purcell, H., Robertson, C., Schar, D., Smith, G. J., Tamburri, M., and Wells, D.: Performance demonstration statement for the Aanderaa Data Instruments' 4319 B Conductivity Sensor. UMCES Technical Report Series. Ref. No. [UMCES] CBL 09–028, 2009.
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, SARF 017 – Final Report, SAMS, 47, 2006.
Glazer, B. T., Luther III, G. W., Konovalov, S. K., Friederich, G. E., Nuzzio, D. B., Trouwborst, R. E., Tebo, B. M., Clement, B., Murray, K., and Romanov, A. S.: Documenting the suboxic zone of the Black Sea viahigh-resolution real-time redox profiling, Deep-Sea Res. Pt. II, 53, 1740–1755, 2006.
Glenn, S. M., Dickey, T. D., Parker, B., and Boicourt, W.: Long-term real-time coastal ocean observation networks, Oceanography, 13, 24–34, 2000.
Gomoiu, M. -T.: Les conséquences négatives de la "floraison" des eaux à Exuviaella cordata OSTENF. du littoral roumain de la mer Noire, Rapp. Comm. int. Mer Médit., 24, 121–122, 1977.
Gomoiu, M. -T.: Marine eutrophication syndrome in the northwestern part of the Black Sea, in: Science of the Total Environment, edited by: Vollenweider, R. A., Elsevier, Amsterdam, 683–692, 1992.
Gomoiu, M. -T.: Impact of naval transport development on marine ecosystems and invasive species problems, J. Environ. Prot. Ecol., 2, 475–481, 2001.
Graf, G., Schulz, R., Peinert, R. and Meyer-Reil, L. -A.: Benthic response to sedimentation events during autumn to spring at a shallow-water station in the Western Kiel Bight, Marine Biology, 77, 235–246, 1983.
Gruber, N., Doney, S. C., Emerson, S. T., Gilbert, D., Kobayashi, T., Körtzinger, A., Johnson, G. C., Johnson, K. S., Riser, S. C., and Ulloa, O.: The Argo Oxygen Program: a White Paper to Promote the Addition of Oxygen Sensors to the International Argo Float Program, Version 5-1, Argo Steering Commitee, Paris, 2007.
Hannig, M., Lavik, G., Kuypers, M. M. M., Woebken, D., Martens-Habbena, W., and Jürgens, K.: Shift from denitrification to anammox after inflow events in the central Baltic Sea, Limnol. Oceanogr., 52, 1336–1345, 2007.
Hansen, H. P., Giesenhagen, H. C., and Behrends, G.: Seasonal and long-term control of the bottom water oxygen deficiency in a stratified shallow water coastal system, ICES J. Mar. Sci., 56, 65–71, 1999.
Hartnett, H. E. and Devol, A. H.: Role of a strong oxygen-deficient zone in the preservation and degradation of organic matter: a carbon budget for the continental margins of northwest Mexico and Washington State, Geochim. Cosmochim. Ac., 67, 247–264, 2003.
Hasiotis, T., Papatheodorou, G., and Ferentinos, G.: A string of large and deep gas-induced depressions (pockmarks) offshore of Killini Peninsula, western Greece, Geo-Mar. Lett., 22, 142–149, 2002.
Haworth, E. Y., Tutin, W., and Lund, J. W. G.: Lake Sediments and Environmental History: Studies in Palaeolimnology and Palaeoecology in Honour of Winifred Tutin, University of Minnesota Press, Minneapolis, 1984.
HELCOM: Eutrophication in the Baltic Sea - An integrated thematic assessment of the effects of nutrient enrichment and eutrophication in the Baltic Sea region, Balt. Sea Environ. Proc. No. 115B, 148 pp., 2009.
Hofmann, A. F., Peltzer, E. T., Walz, P. M., and Brewer, P. G.: Hypoxia by degrees: establishing definitions for a changing ocean, Deep-Sea Res. Pt. I, 58, 1212–1226, 2011.
Hulthe, G., Hulth, S., and Hall, P. O. J.: Effect of oxygen on degradation rate of refractory and labile organic matter in continental margin sediments. Geochim. Cosmochim. Acta, 62, 1319–1328, 1998.
Humborg, C., Ittekkot, V., Cociasu, A., and v. Bodungen, B.: Effect of Danube River dam on Black Sea biogechemistry and ecosystem structure, Nature, 386, 385–388, 1997.
Idso, S. B.: On the concept of lake stability, Limnol. Oceanogr., 18, 681–683, 1973.
Jankowski, T., Livingstone, D. M., Bührer, H., Forster, R., and Niederhauser, P.: Consequences of the 2003 European heat wave for lake temperature profiles, thermal stability, and hypolimnetic oxygen depletion: implications for a warmer world, Limnol. Oceanogr., 51, 815–819, 2006.
Jannasch, H. W., Coletti, L. J., Johnson, K. S., Fitzwater, S. E., Needoba, J. A., and Plant, J. N.: The Land/Ocean Biogeochemical Observatory: a robust networked mooring system for continuously monitoring complex biogeochemical cycles in estuaries, Limnol. Oceanogr. -Meth., 6, 263–273, 2008.
Jones, G. A. and Gagnon, A. R.: Radiocarbon chronology of Black Sea sediments, Deep-Sea Res. Pt. I, 41, 531–557, https://doi.org/10.1016/0967-0637(94)90094-9, 1994.
Kamberis, E., Rigakis, N., Tsaila-Monopolis, S., Ioakim, C., and Sotiropoulos, S.: Shallow biogenic gas-accumulations in Late Cenozoic sands of Katakolon Peninsula, Western Greece, Special Publications, Geol. Soc. Greece, 9, 121–138, 2000.
Karakitsios, V. and Rigakis, N.: Evolution and petroleum potential of Western Greece, J. Petrol. Geol., 30, 197–218, 2007.
Keeling, R. F., Körtzinger, A., and Gruber, N.: Ocean deoxygenation in a warming world, Ann. Rev. Mar. Sci., 2, 199–229, 2010.
Kemp, W. M., Testa, J. M., Conley, D. J., Gilbert, D., and Hagy, J. D.: Temporal responses of coastal hypoxia to nutrient loading and physical controls, Biogeosciences, 6, 2985–3008, https://doi.org/10.5194/bg-6-2985-2009, 2009.
Kessler, J. D., Valentine, D. L., Redmond, M. C., Du, M., Chan, E. W., Mendes, S. D., Quiroz, E. W., Villanueva, C. J., Shusta, S. S., Werra, L. M., Yvon-Lewis, S. A., and Weber, T. C.: A persistent oxygen anomaly reveals the fate of spilled methane in the deep Gulf of Mexico, Science, 331, 312–315, 2011.
Kessler, J. D., Reeburgh, W. S., Southon, J., and Varela, R.: Fossil methane source dominates Cariaco Basin water column methane geochemistry, Geophys. Res. Lett., 32, L12609, 2005.
Kiseleva, M. I. and Slavina, O. J.: Bottom biocenoses off the west coast of the Crimea, Proc. of Sevastop. Biol. St., 15, 152–177, 1964 (in Russian).
Kirf, M. K., Dinkel, C., Schubert, C. J., and Wehrli, B.: Submicromolar oxygen profiles at the oxic-anoxic boundary of temperate lakes, Aquat. Geochem., 20, 39–57, https://doi.org/10.1007/s10498-013-9206-7, 2014a.
Kirf, M. K., Røy, H., Holtappels, M., Fischer, J.P., Schubert, C. J., and Wehrli, B.: Redox gradients at the low oxygen boundary of lakes, Aquat. Sci., in review, 2014b.
Kohler, H. P., Ahring, B., Albella, C., Ingvorsen, K., Keweloh, H., Laczko, E., Stupperich, E., and Tomei, F.: Bacteriological studies on the sulfur cycle in the anaerobic part of the hypolimnion and in the surface sediments of Rotsee in Switzerland, FEMS Microbiol. Lett., 21, 279–286, 1984.
Konovalov, S. K. and Murray, J. W.: Variations in the chemistry of the Black Sea on a time scale of decades (1960–1995), J. Marine Syst., 31, 217–243, 2001.
Konovalov, S. K., Luther III, G. W., Friederich, G. E., Nuzzio, D. B., Tebo, B. M., Murray, J. W., Oguz, T., Glazer, B. T., Trouwborst, R. E., Clement, B., Murray, K. J., and Romanov, A. S.: Lateral injection of oxygen with the Bosporus plume: fingers of oxidizing potential in the Black Sea, Limnol. Oceanogr., 48, 2369–2376, 2003.
Konovalov, S. K., Murray, J. W., and Luther, G. W.: Basic processes of the Black Sea biogeochemistry, Oceanography, 18, 28–35, 2005.
Konovalov, S. K., Murray, J. W., Luther, G. W., and Tebo, B. M.: Processes controlling the redox budget for the oxic/anoxic water column of the Black Sea, Deep-Sea Res. Pt. II, 53, 1817–1841, 2006.
Korotaev, G., Oguz, T., and Riser, S.: Intermediate and deep currents of the Black Sea obtained from autonomous profiling floats, Deep-Sea Res. Pt. II, 53, 1901–1910, 2006.
Kountoura, K. and Zacharias, I.: Temporal and spatial distribution of hypoxic/seasonal anoxic zone in Amvrakikos Gulf, Western Greece, Estuar. Coast. Shelf S., 94, 123–128, 2011.
Kuhn, W.: Introduction to Spatial Data Infrastructures, available at: http://www.docstoc.com/docs/2697206/Introduction-to-Spatial-Data-Infrastructureskl, 2005.
Langmead, O., McQuatters-Gollop, A., Mee, L. D., Friedrich, J., Gilbert, A. J., Gomoiu, M. -T., Jackson, E. L., Knudsen, S., Minicheva, G., and Todorova, V.: Recovery or decline of the northwestern Black Sea: a societal choice revealed by socio-ecological modelling, Ecol. Model., 220, 2927–2939, 2009.
Latif, M. A., Ozsoy, E., Oguz, T., and Ünlüata, Ü.: Observations of the Mediterranean Inflow into the Black-Sea, Deep-Sea Res. Pt. I, 38, S711–S723, 1991.
Lee, C.: The use of stratified water bodies to compare intrinsic rates of decomposition in oxic and anoxic systems, Geochim. Cosmochim. Ac., 56, 3323–3335, 1992.
Lehmann, A., Getzlaff, K., and Harlaß, J.: Detailed assessment of climate variability in the Baltic Sea area for the period 1958 to 2009, Clim. Res., 46, 185–196, 2011.
Leipe, T., Dippner, J. W., Hille, S., Voss, M., Christiansen, C., and Bartholdy, J.: Environmental changes in the central Baltic Sea during the past 1000 years: inferences from sedimentary records, hydrography and climate, Oceanologia, 20, 23–41, 2008.
Lennartz, S.: Time-series analysis and development of a 1D box model to simulate trace gas concentrations at the Time Series Station Boknis Eck, Baltic Sea, MSc thesis, Technische Universität Braunschweig, 96 pp., 2013.
Leonardos, I. and Sinis, A.: Fish mass mortality in the Etolikon Lagoon, Greece: the role of local geology, Cybium, 21, 201–206, 1997.
Levin, L. A.: Oxygen minimum zone benthos: adaptation and community response to hypoxia, Annu. Rev. Oceanogr. Mar. Biol., 41, 1–45, 2003.
Levin, L. A., Ekau, W., Gooday, A. J., Jorissen, F., Middelburg, J. J., Naqvi, S. W. A., Neira, C., Rabalais, N. N., and Zhang, J.: Effects of natural and human-induced hypoxia on coastal benthos, Biogeosciences, 6, 2063–2098, https://doi.org/10.5194/bg-6-2063-2009, 2009.
Livingstone, D. M.: Temporal structure in the deep-water temperature of four Swiss lakes: a short-term climatic change indicator?, Verhandlungen der Internationalen Vereinigung für theoretische und angewandte Limnologie, 25, 75–81, 1993.
Livingstone, D. M.: An example of the simultaneous occurrence of climate-driven "sawtooth" deep-water warming/cooling episodes in several Swiss lakes, Verhandlungen der Internationalen Vereinigung für theoretische und angewandte Limnologie, 26, 822–826, 1997.
Livingstone, D. M.: Impact of secular climate change on the thermal structure of a large temperate central European lake, Climatic Change, 57, 205–225, 2003.
Livingstone, D. M. and Imboden, D. M.: The prediction of hypolimnetic oxygen profiles: a plea for a deductive approach, Can. J. Fish. Aquat. Sci., 53, 924–932, 1996.
Lo Bue, N., Vangriesheim, A., Khripounoff, A., and Soltwedel, T.: Anomalies of oxygen measurements performed with Aanderaa optodes, Journal of Operational Oceanography, 4, 27–37, 2011.
Luth, U., Luth, C., Stokozov, N. A. and Gulin, M. B.: The chemocline rise effect on the northwestern slope of the Black Sea, in: Methane Gas Seep Explorations in the Black Sea (MEGASEEBS), Project Report. Ber. Zentrum Meeres- u. Klimaforsch., edited by: Luth, U., Luth, C., and Thiel, H., Univ. Hamburg, Reihe E, 14, 59–77, 1998.
Luther III, G. W., Ma, S., Trouwborst, R., Grazer, B., Blickley, M., Scarborough, R., and Mensinger, M.: The role of anoxia, H2S, storm events in fish kills of dead-end canals of Delaware Inland Bays, Estuaries, 27, 551–560, 2004.
Manley, O.: Branching of Atlantic Water within the Greenland–Spitsbergen passage: an estimate of recirculation, J. Geophys. Res., 100, 20627–20634, 1995.
Marinaro, G., Etiope, G., Gasparoni, F., Calore, D., Cenedese, S., Furlan, F., Masson, M., Favali, F., and Blandin, J.: GMM – a gas monitoring module for long-term detection of methane leakage from the seafloor, Environ. Geol., 46, 1053–1058, 2004.
Marinaro, G., Etiope, G., Gasparoni, F., Furlan, F., and Bruni, F.: Gas seepage detection and monitoring at seafloor, in: 10th Offshore Mediterranean Conference and Exhibition, 23–25 March, Ravenna, Italy, http://shop.omc.it/en-IT/gas-seepage-detection-and-monitoring-at-seafloor/product-detail/?srch=marinaro&submit=Search&id_product=814, 2011.
Martens, C. S. and Klump, J. V.: Biogeochemical cycling in an organic-rich coastal marine basin – I. Methane sediment-water exchange processes, Geochim. Cosmochim. Ac., 44, 471–490, 1980.
Martini, M., Butman, B., and Mickelson, M. J.: Long-term performance of Aanderaa optodes and Sea-Bird SBE-43 dissolved-oxygen sensors bottom mounted at 32 m in Massachusetts Bay, J. Atmos. Ocean. Tech., 24, 1924–1935, 2007.
McManus, J., Berelson, W. M., Coale, K. H., Johnson, K. S., and Kilgore, T. E.: Phosphorus regeneration in continental margin sediments, Geochim. Cosmochim. Ac., 61, 2891–2907, 1997.
Mee, L. D.: The Black Sea in crisis: a need for concerted international action, AMBIO, 21, 278–286, 1992.
Mee, L. D., Friedrich, J., and Gomoiu, M. -T.: Restoring the Black Sea in times of uncertainty, Oceanography, 18, 32–43, 2005.
Meier, H. E. M., Andersson, H. C., Eilola, K., Gustafsson, B. G., Kuznetsov, I., Müller-Karulis, B., Neumann, T., and Savchuk, O. P.: Hypoxia in future climates: a model ensemble study for the Baltic Sea, Geophys. Res. Lett., 38, L24608, https://doi.org/10.1029/2011GL049929, 2011.
Meletios Metropolitan of Artas and Nafpaktos: Geography New and Old, 4, Venice, 200 pp., 1807.
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., Soetaert, K., Herman, P. M. J., and Heip, C. H. R.: Denitrification in marine sediments: a model study, Global Biogeochem. Cy., 10, 661–673, 1996.
Moller, H. and Anders, K.: Marine Fishes; Fishes; Diseases; Parasites, Moller, Kiel, 365 pp., 1986.
Monteiro, P. M. S., van der Plas, A., Mohrholz, V., Mabille, E., Pascall, A., and Joubert, W.: Variability of natural hypoxia and methane in a coastal upwelling system: oceanic physics or shelf biology?, Geophys. Res. Lett., 33, L16614, https://doi.org/10.1029/2006GL026234, 2006.
Murray, J. W., Codispoti, L. A., and Friederich, G. E.: Oxidation-reduction environments. The suboxic zone in the Black Sea, in: Aquatic Chemistry: Interfacial and Interspecies Processes, edited by: Huang, C. P., O'Melia, C. R., and Morgan, J. J., ACS Advances in Chemistry Series, 157–176, 1995.
Naeher, S., Smittenberg, R. H., Gilli, A., Kirilova, E. P., Lotter, A. F., and Schubert, C. J.: Impact of recent lake eutrophication on microbial community changes as revealed by high resolution lipid biomarkers in Rotsee (Switzerland), Org. Geochem., 49, 86–95, 2012.
Naeher, S., Schaeffer, P., Adam, P., and Schubert, C. J.: Maleimides in recent sediments – Using chlorophyll degradation products for palaeoenvironmental reconstructions, Geochim. Cosmochim. Ac., 119, 248–263, 2013a.
Naeher, S., Gilli, A., North, R. P., Hamann, Y., and Schubert, C. J.: Tracing bottom water oxygenation with sedimentary Mn/Fe ratios in Lake Zurich, Switzerland, Chem. Geol., 352, 125–133, 2013b.
Naeher, S., Niemann, H., Peterse, F., Smittenberg, R. H., Zigah, P. K., and Schubert, C. J.: Tracing the methane cycle with lipid biomarkers in Lake Rotsee (Switzerland), Org. Geochem., 66, 174–181, https://doi.org/10.1016/j.orggeochem.2013.11.002, 2014.
Nayar, A.: A lakeful of trouble, Nature, 460, 321–323, 2009.
Nealson, K. H. and Saffarini, D.: Iron and Manganese in anaerobic respiration environmental significance, Annu. Rev. Microbiol., 48, 311–343, 1994.
Neumann, T.: Climate-change effects on the Baltic Sea ecosystem: a model study, J. Marine Syst., 81, 213–224, 2010.
Nilsson, H. C. and Rosenberg, R.: Succession in marine benthic habitats and fauna in response to oxygen deficiency: analysed by sediment profile-imaging and by grab samples, Mar. Ecol. -Prog. Ser., 197, 139–149, 2000.
Nordberg, K., Filipsson, H. L., Gustafsson, M., Harland, R., and Roos, P.: Climate, hydrographic variations and marine benthic hypoxia in Koljöfjord, Sweden, J. Sea Res., 46, 187–200, 2001.
North, R. P., Livingstone, D. M., Hari, R. E., Niederhauser, P., Köster, O., and Kipfer, R.: The physical impact of the late 1980s climate regime shift on Swiss lakes and rivers, Inland Waters, 3, 341–350, 2013.
North, R. P., North, R. L., Livingstone, D. M., Köster, O., and Kipfer, R.: Long-term changes in hypoxia and soluble reactive phosphorus in the hypolimnion of a large temperate lake: consequences of a climate regime shift, Glob. Change Biol., 20, 3, 811–823, https://doi.org/10.1111/gcb.12371, 2014.
Oguz, T. and Gilbert, D.: Abrupt transitions of the top-down controlled Black Sea pelagic ecosystem during 1960–2000: evidence for regime-shifts under strong fishery exploitation and nutrient enrichment modulated by climate-induced variations, Deep-Sea Res. Pt. I, 54, 220–242, 2007.
Oguz, T., Dippner, J. W., and Kaymaz, Z.: Climatic regulation of the Black Sea hydro-meteorological and ecological properties at interannual-to-decadal time scales, J. Marine Syst., 60, 235–254, 2006.
O'Sullivan, P. E. and Reynolds, C. S.: The Lakes Handbook: Lake Restoration and Rehabilitation, Blackwell Science, Oxford, 2005.
Papatheodorou, G., Hasiotis, T., and Ferentinos, G.: Gas charged sediments in the Aegean and Ionian seas, Greece, Mar. Geol., 112, 171–184, 1993.
Pearson, T. H. and Rosenberg, R.: Macrobenthic succession in relation to organic enrichment and pollution of the marine environment, Oceanogr. Mar. Biol., 16, 229–311, 1978.
Peeters, F., Livingstone, D. M., Goudsmit, G. -H., Kipfer, R., and Forster, R.: Modeling 50 years of historical temperature profiles in a large central European lake, Limnol. Oceanogr., 47, 186–197, 2002.
Petersen, C. G. J.: On the animal communities of the sea bottom in the Skagerak, the Christiania Fjord and the Danish waters, Report from the Danish Biological Station, 23, 1–28, 1915.
Pianka, E. R.: On r and K selection, Am. Nat., 104, 592–597, 1970.
Pianka, E. R.: Evolutionary Ecology, 2 Edn., Harper and Row, New York, 397 pp., 1978.
Pitkanen, H., Lehtoranta, J., and Raike, A.: Internal nutrient fluxes counteract decreases in external load: the case of the estuarial eastern Gulf of Finland, Baltic Sea, Ambio, 30, 195–201, 2001.
Preisler, A., de Beer, D., Lichtschlag, A., Lavik, G., Boetius, A., and Jørgensen, B. B.: Biological and chemical sulfide oxidation in a Beggiatoa inhabited marine sediment, ISME J., 1, 341–353, 2007.
Prien, R. D. and Schulz-Bull, D. E.: The Gotland Deep Environmental Sampling Station in the Baltic Sea, OCEANS, 2011 IEEE, Spain, 1–5, 2011.
Rabalais, N. N. and Gilbert, D.: Distribution and consequences of hypoxia, in: Watersheds, Bays and Bounded Seas, edited by: Urban, E., Sundby, B., Malanotte-Rizzoli, P., and Melillo, J. M., Island Press, Washington, DC, 209–226, 2009.
Reissmann, J., Burchard, H., Feistel, R., Hagen, E., Lass, H. U., Mohrholz, V., Nausch, G., Umlauf, L., and Wieczorek, G.: State-of-the-art review on vertical mixing in the Baltic Sea and consequences for eutrophication, Prog. Oceanogr., 82, 47–80, 2009.
Rempfer, J., Livingstone, D. M., Forster, R., and Blodau, C.: Response of hypolimnetic oxygen concentrations in deep Swiss perialpine lakes to interannual variations in winter climate, Verhandlungen der Internationalen Vereinigung für theoretische und angewandte Limnologie, 30, 717–721, 2009.
Rempfer, J., Livingstone, D. M., Blodau, C., Forster, R., Niederhauser, P., and Kipfer, R.: The effect of the exceptionally mild European winter of 2006–2007 on temperature and oxygen profiles in lakes in Switzerland: a foretaste of the future?, Limnol. Oceanogr., 55, 2170–2180, 2010.
Revsbech, N. P., Larsen, L. H., Gundersen, J., Dalsgaard, T., Ulloa, O., and Thamdrup, B.: Determination of ultra-low oxygen concentrations in oxygen minimum zones by the STOX sensor, Limnol. Oceanogr.-Meth., 7, 371–381, 2009.
Revsbech, N. P., Thamdrup, B., Dalsgaard, T., and Canfield, D. E.: Construction of STOX oxygen sensors and their application for determination of O2 concentrations in oxygen minimum zones, Method. Enzymol., 486, 325–341, 2011.
Riedel, B., Zuschin, M., and Stachowitsch, M.: Tolerance of benthic macrofauna to hypoxia and anoxia in shallow coastal seas: a realistic scenario, Mar. Ecol. -Prog. Ser., 458, 39–52, 2012.
Riser, S. and Johnson, K.: Net production of oxygen in the subtropical ocean, Nature, 451, 323–325, 2008.
Rodionov, S. N. and Overland, J. E.: Application of a sequential regime shift detection method to the Bering Sea ecosystem, ICES J. Mar. Sci., 62, 328–333, 2005.
Rozan, T. F., Taillefert, M., Trouwborst, R. E., Glazer, B. T., Ma, S. F., Herszage, J., Valdes, L. M., Price, K. S., and Luther, G. W.: Iron-sulfur-phosphorus cycling in the sediments of a shallow coastal bay: implications for sediment nutrient release and benthic macroalgal blooms, Limnol. Oceanogr., 47, 1346–1354, 2002.
Rudels, B., Meyer, R., Fahrbach, E., Ivanov, V. V., Osterhus, S., Quadfasel, D., Schauer, U., Tverberg, V., and Woodgate, R. A.: Water mass distribution in Fram Strait and over the Yermak Plateau in summer 1997, Ann. Geophys., 18, 687–705, 2000.
Sale, J. W. and Skinner, W. W.: The vertical distribution of dissolved oxygen and the precipitation of salt water in certain tidal areas, J. Frankl. Inst., 184, 837–848, 1917
Schaller, T. and Wehrli, B.: Geochemical focusing of manganese in lake sediments – an indicator of deep-water oxygen conditions, Aquat. Geochem., 2, 359–378, 1996.
Schauer, U., Fahrbach, E., Osterhus, S., and Rohardt, G.: Arctic warming through the Fram Strait: oceanic heat transport from 3 years of measurements, J. Geophys. Res., 109, C06026, https://doi.org/10.1029/2003JC001823, 2004.
Schmidt, W.: Über Temperatur- und Stabilitätsverhältnisse von Seen, Geogr. Ann. A, 10, 145–177, 1928.
Schneider, P. and Hook, S. J.: Space observations of inland water bodies show rapid surface warming since 1985, Geophys. Res. Lett., 37, L22405, https://doi.org/10.1029/2010GL045059, 2010.
Schubert, C. J., Lucas, F., Durisch-Kaiser, E., Stierli, R., Diem, T., Scheidegger, O., Vazquez, F., and Müller, B.: Oxidation and emission of methane in a monomictic lake (Rotsee, Switzerland), Aquat. Sci., 72, 455–466, 2010.
Sinninghe Damsté, J. S., Kenig, F., Koopmans, M. P., Koster, J., Schouten, S., Hayes, J. M., and DeLeeuw, J. W.: Evidence for gammacerane as an indicator of water column stratification, Geochim. Cosmochim. Ac., 59, 1895–1900, 1995.
Skolka, V. H. and Cautis, I.: Floraison d'Exuviaella cordata Ostenfs. et ses conséquences sur la pêche maritime en Roumanie au cours de l'année 1969, IRCM Constanta, Cercetări Marine – Recherches marines, 1, 59–82, 1971.
Skopintsev, B. A.: Formirovanie sovremennogo khimicheskogo sostava vod Chernogo morya (Formation of the Present Chemical Structure of the Black Sea), Gidrometeoizdat, Leningrad, 1975.
Smetacek, V., von Bodungen, B., Knoppers, B., Peinert, R., Pollehne, F., Stegmann, P., and Zeitzschel, B.: Seasonal stages characterizing the annual cycle of an inshore pelagic system, Rapp. p. -v. réun. – Cons. int. explor. mer, Succeeding: ICES marine science symposia International Council for the Exploration of the Sea, 183, 126–135, 1984.
Soltwedel, T., Bauerfeind, E., Bergmann, M., Budaeva, N., Hoste, E., Jaeckisch, N., Juterzenka, K. V., Matthießen, J., Mokievsky, V., Nöthig, E. M., Quéric, N., Sablotny, B., Sauter, E., Schewe, I., Urban-Malinga, B., Wegner, J., Wlodarska-Kowalczuk, M., and Klages, M.: HAUSGARTEN: multidisciplinary investigations at a deep-sea, long-term observatory in the Arctic Ocean, Oceanography, 18, 46–61, 2005.
Sorokin, Y. I.: On the primary production and bacterial activities in the Black Sea, Journal du Conseil Permanent International pour l'Exploration de la Mer, 29, 41–54, 1964.
Stadelmann, P.: Der Zustand des Rotsees bei Luzern, in: Maihof-Rotsee. Geschichte und Eigenart eines Quartiers, edited by: Quartierverein Maihof, Quartierverein Maihof, Luzern, 54–61, 1980 (in German).
Stanev, E. V., He, Y., Grayek, S., and Boetius, A.: Oxygen dynamics in the Black Sea as seen by Argo profiling floats, Geophys. Res. Lett., 40, 3085–3090, 2013.
Steckbauer, A., Duarte, C. M., Cartsensen, J., Vaquer-Sunyer, R., and Conley, D. J.: Ecosystem impacts of hypoxia: thresholds of hypoxia and pathways to recovery, Environ. Res. Lett., 6, 025003, https://doi.org/10.1088/1748-9326/6/2/025003, 2011.
Stefan, H. G. and Fang, X.: Model simulations of dissolved oxygen characteristics of Minnesota lakes: past and future, J. Environ. Manage., 18, 73–92, 1994.
Stefan, H. G., Hondzo, M., Fang, X., Eaton, J. G., and McCormick, J. H.: Simulated long-term temperature and dissolved oxygen characteristics of lakes in the north-central United States and associated fish habitat limits, Limnol. Oceanogr., 4, 1124–1135, 1996.
Stefan, H. G., Fang, X., and Hondzo, M.: Simulated climate change effects on year-round water temperatures in temperate zone lakes, Climatic Change, 4, 547–576, 1998.
Stolper, D. A., Revsbech, N. P., and Canfield, D. E.: Aerobic growth at nanomolar oxygen concentrations, P. Natl. Acad. Sci. USA, 107, 18755–18760, 2010.
Stramma, L., Johnson, G. C., Sprintall, J., and Mohrholz, V.: Expanding oxygen-minimum zones in the tropical oceans, Science, 320, 655–658, 2008.
Tamburri,M. N.: Performance Verification Statement for the Aanderaa Instruments Inc. Dissolved Oxygen Optode 3830/3930/3835. UMCES Technical Report Series. Ref. No. [UMCES] CBL 04–116, 2004.
Teaca, A., Begun, T., and Gomoiu, M. -T.: Recent data on benthic populations from hard bottom mussel community in the Romanian Black Sea coastal zone, GeoEcoMarina, 12, 43–51, 2006.
Tengberg, A., Hovdenes, J., Andersson, H. J., Brocandel, O., Diaz, R., Hebert, D., Arnerich, T., Huber, C., Koertzinger, A., Khripounoff, A., Rey, F., Roenning, C., Schimanski, J., Sommer, S., and Stangelmayer, A.: Evaluation of a lifetime-based optode to measure oxygen in aquatic systems, Limnol. Oceanogr. -Meth., 4, 7–17, 2006.
Thamdrup, B., Dalsgaard, T., and Revsbech, N. P.: Widespread functional anoxia in the oxygen minimum zone of the Eastern South Pacific, Deep-Sea Res. Pt. I, 65, 36–45, 2012.
Tolmazin, D.: Changing Coastal oceanography of the Black Sea. I: Northwesternshelf, Prog. Oceanogr., 15, 217–276, 1985.
Uchida, H., Kawano, T., Kaneko, I., and Fukasawa, M.: In-situ calibration of optode-based oxygen sensors, J. Atmos. Ocean. Tech., 25, 2271–2281, 2008.
Ünlüata, Ü., Oguz, T., Latif, M. A., and Özsoy, E.: On the physical oceanography of the Turkish straits, in: NATO ASI, edited by: Pratt, L. J., 25–60, 1990.
Vaquer-Sunyer, R. and Duarte, C. M.: Thresholds of hypoxia for marine biodiversity, P. Natl. Acad. Sci. USA, 105, 15452–15457, 2008.
Viktorsson, L., Ekeroth, N., Nilsson, M., Kononets, M., and Hall, P. O. J.: Phosphorus recycling in sediments of the central Baltic Sea, Biogeosciences, 10, 3901–3916, https://doi.org/10.5194/bg-10-3901-2013, 2013.
Ward, B. B., Kilpatrick, K. A., Novelli, P. C., and Scranton, M. I.: Methane oxidation and methane fluxes in the ocean surface layer and deep anoxic waters, Nature, 327, 226–229, 1987.
Weslawski, J. M., Kwasniewski, S., and Stempniewicz, L.: Warming in the Arctic may result in the negative effects of increased biodiversity, Polarforschung, 78, 105–108, 2009.
Yunev, O. A., Vedernikov, V. I., Basturk, O., Yilmaz, A., Kideys, A. E., Moncheva, S., and Konovalov, S. K.: Long-term variations of surface chlorophyll a and primary production in the open Black Sea, Mar. Ecol. -Prog. Ser., 230, 11-28, https://doi.org/10.3354/meps230011, 2002.
Yunev, O. A., Carstensen, J., Moncheva, S., Khaliulin, A., Ǽrtebjerg, G., and Nixon, S.: Nutrient and phytoplankton trends on the western Black Sea shelf in response to cultural eutrophication and climate changes, Estuar. Coast. Shelf S., 74, 63–76, 2007.
Zaitsev, Y. P.: Recent changes in the trophic structure of the Black Sea, Fish. Oceanogr., 1, 2, 180–198, 1992.
Zhang, J., Gilbert, D., Gooday, A. J., Levin, L., Naqvi, S. W. A., Middelburg, J. J., Scranton, M., Ekau, W., Peña, A., Dewitte, B., Oguz, T., Monteiro, P. M. S., Urban, E., Rabalais, N. N., Ittekkot, V., Kemp, W. M., Ulloa, O., Elmgren, R., Escobar-Briones, E., and Van der Plas, A. K.: Natural and human-induced hypoxia and consequences for coastal areas: synthesis and future development, Biogeosciences, 7, 1443–1467, https://doi.org/10.5194/bg-7-1443-2010, 2010.
Zimmermann, U., Forster, R., and Sontheimer, H.: Long-Term Change in the Water Quality of Lake Zurich, Upper Lake Zurich and the Lake of Walenstadt, City of Zurich Water Supply, Technical Report, 1991, (in German).
Züllig, H.: Pigmente phototropher Bakterien in Seesedimenten und ihre Bedeutung für die Seenforschung, Aquat. Sci., 47, 87–126, 1985, (in German).
Altmetrics
Final-revised paper
Preprint