Articles | Volume 17, issue 16
https://doi.org/10.5194/bg-17-4223-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-17-4223-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
26 Aug 2020
Research article |
| 26 Aug 2020
| 26 Aug 2020
The impact of intertidal areas on the carbonate system of the southern North Sea
Fabian Schwichtenberg
Theoretical Oceanography, Institute of Oceanography, University of Hamburg, Bundesstr. 53,
20146 Hamburg, Germany
present address: Federal Maritime and Hydrographic Agency,
Bernhard-Nocht-Str. 78, 20359 Hamburg, Germany
Institute of Coastal Research, Helmholtz-Zentrum Geesthacht (HZG),
Max-Planck-Str. 1, 21502 Geesthacht, Germany
Theoretical Oceanography, Institute of Oceanography, University of Hamburg, Bundesstr. 53,
20146 Hamburg, Germany
Michael Ernst Böttcher
Geochemistry & Isotope Biogeochemistry Group, Department of Marine
Geology, Leibniz Institute for Baltic Sea Research (IOW), Seestr. 15, 18119
Warnemünde, Germany
Marine Geochemistry, University of Greifswald, Friedrich-Ludwig-Jahn
Str. 17a, 17489 Greifswald, Germany
Department of Maritime Systems, Interdisciplinary Faculty, University
of Rostock, Albert-Einstein-Str. 21, 18059 Rostock, Germany
Helmuth Thomas
Institute of Coastal Research, Helmholtz-Zentrum Geesthacht (HZG),
Max-Planck-Str. 1, 21502 Geesthacht, Germany
Vera Winde
Geochemistry & Isotope Biogeochemistry Group, Department of Marine
Geology, Leibniz Institute for Baltic Sea Research (IOW), Seestr. 15, 18119
Warnemünde, Germany
Kay-Christian Emeis
Institute of Coastal Research, Helmholtz-Zentrum Geesthacht (HZG),
Max-Planck-Str. 1, 21502 Geesthacht, Germany
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Seyed Reza Saghravani, Michael Ernst Böttcher, Wei-Li Hong, Karol Kuliński, Aivo Lepland, Arunima Sen, and Beata Szymczycha
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-13, https://doi.org/10.5194/essd-2024-13, 2024
Revised manuscript accepted for ESSD
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A comprehensive study conducted in 2021 examined the distributions of dissolved nutrients and carbon in the western Spitsbergen fjords during the high melting season. Significant spatial variability was observed in the water column and pore water concentrations of constituents, highlighting the unique biogeochemical characteristics of each fjord and their potential impact on ecosystem functioning and oceanographic processes.
Mona Norbisrath, Justus E. E. van Beusekom, and Helmuth Thomas
EGUsphere, https://doi.org/10.5194/egusphere-2023-2595, https://doi.org/10.5194/egusphere-2023-2595, 2023
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Observational study that investigated total alkalinity (TA) in the Dutch Wadden Sea. We collected discrete water samples to identify spatial TA distribution patterns and to locate and shed light on potential TA sources. By observing a tidal cycle in the Ameland Inlet, we identified the sediments as a local TA source and assumed aerobic metabolic processes eg CaCO3 dissolution as a TA source in the upper oxic sediments, and anaerobic metabolic processes as a TA source in the deeper anoxic ones.
Mona Norbisrath, Andreas Neumann, Kirstin Dähnke, Tina Sanders, Andreas Schöl, Justus E. E. van Beusekom, and Helmuth Thomas
Biogeosciences, 20, 4307–4321, https://doi.org/10.5194/bg-20-4307-2023, https://doi.org/10.5194/bg-20-4307-2023, 2023
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Total alkalinity (TA) is the oceanic capacity to store CO2. Estuaries can be a TA source. Anaerobic metabolic pathways like denitrification (reduction of NO3− to N2) generate TA and are a major nitrogen (N) sink. Another important N sink is anammox that transforms NH4+ with NO2− into N2 without TA generation. By combining TA and N2 production, we identified a TA source, denitrification, occurring in the water column and suggest anammox as the dominant N2 producer in the bottom layer of the Ems.
Nele Lehmann, Hugues Lantuit, Michael Ernst Böttcher, Jens Hartmann, Antje Eulenburg, and Helmuth Thomas
Biogeosciences, 20, 3459–3479, https://doi.org/10.5194/bg-20-3459-2023, https://doi.org/10.5194/bg-20-3459-2023, 2023
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Riverine alkalinity in the silicate-dominated headwater catchment at subarctic Iskorasfjellet, northern Norway, was almost entirely derived from weathering of minor carbonate occurrences in the riparian zone. The uphill catchment appeared limited by insufficient contact time of weathering agents and weatherable material. Further, alkalinity increased with decreasing permafrost extent. Thus, with climate change, alkalinity generation is expected to increase in this permafrost-degrading landscape.
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
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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.
Mona Norbisrath, Johannes Pätsch, Kirstin Dähnke, Tina Sanders, Gesa Schulz, Justus E. E. van Beusekom, and Helmuth Thomas
Biogeosciences, 19, 5151–5165, https://doi.org/10.5194/bg-19-5151-2022, https://doi.org/10.5194/bg-19-5151-2022, 2022
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Total alkalinity (TA) regulates the oceanic storage capacity of atmospheric CO2. TA is also metabolically generated in estuaries and influences coastal carbon storage through its inflows. We used water samples and identified the Hamburg port area as the one with highest TA generation. Of the overall riverine TA load, 14 % is generated within the estuary. Using a biogeochemical model, we estimated potential effects on the coastal carbon storage under possible anthropogenic and climate changes.
Bryce Van Dam, Nele Lehmann, Mary A. Zeller, Andreas Neumann, Daniel Pröfrock, Marko Lipka, Helmuth Thomas, and Michael Ernst Böttcher
Biogeosciences, 19, 3775–3789, https://doi.org/10.5194/bg-19-3775-2022, https://doi.org/10.5194/bg-19-3775-2022, 2022
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We quantified sediment–water exchange at shallow sites in the North and Baltic seas. We found that porewater irrigation rates in the former were approximately twice as high as previously estimated, likely driven by relatively high bioirrigative activity. In contrast, we found small net fluxes of alkalinity, ranging from −35 µmol m−2 h−1 (uptake) to 53 µmol m−2 h−1 (release). We attribute this to low net denitrification, carbonate mineral (re-)precipitation, and sulfide (re-)oxidation.
Cordula Nina Gutekunst, Susanne Liebner, Anna-Kathrina Jenner, Klaus-Holger Knorr, Viktoria Unger, Franziska Koebsch, Erwin Don Racasa, Sizhong Yang, Michael Ernst Böttcher, Manon Janssen, Jens Kallmeyer, Denise Otto, Iris Schmiedinger, Lucas Winski, and Gerald Jurasinski
Biogeosciences, 19, 3625–3648, https://doi.org/10.5194/bg-19-3625-2022, https://doi.org/10.5194/bg-19-3625-2022, 2022
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Methane emissions decreased after a seawater inflow and a preceding drought in freshwater rewetted coastal peatland. However, our microbial and greenhouse gas measurements did not indicate that methane consumers increased. Rather, methane producers co-existed in high numbers with their usual competitors, the sulfate-cycling bacteria. We studied the peat soil and aimed to cover the soil–atmosphere continuum to better understand the sources of methane production and consumption.
Krysten Rutherford, Katja Fennel, Dariia Atamanchuk, Douglas Wallace, and Helmuth Thomas
Biogeosciences, 18, 6271–6286, https://doi.org/10.5194/bg-18-6271-2021, https://doi.org/10.5194/bg-18-6271-2021, 2021
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Using a regional model of the northwestern North Atlantic shelves in combination with a surface water time series and repeat transect observations, we investigate surface CO2 variability on the Scotian Shelf. The study highlights a strong seasonal cycle in shelf-wide pCO2 and spatial variability throughout the summer months driven by physical events. The simulated net flux of CO2 on the Scotian Shelf is out of the ocean, deviating from the global air–sea CO2 flux trend in continental shelves.
Chantal Mears, Helmuth Thomas, Paul B. Henderson, Matthew A. Charette, Hugh MacIntyre, Frank Dehairs, Christophe Monnin, and Alfonso Mucci
Biogeosciences, 17, 4937–4959, https://doi.org/10.5194/bg-17-4937-2020, https://doi.org/10.5194/bg-17-4937-2020, 2020
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Major research initiatives have been undertaken within the Arctic Ocean, highlighting this area's global importance and vulnerability to climate change. In 2015, the international GEOTRACES program addressed this importance by devoting intense research activities to the Arctic Ocean. Among various tracers, we used radium and carbonate system data to elucidate the functioning and vulnerability of the hydrographic regime of the Canadian Arctic Archipelago, bridging the Pacific and Atlantic oceans.
Alexis Beaupré-Laperrière, Alfonso Mucci, and Helmuth Thomas
Biogeosciences, 17, 3923–3942, https://doi.org/10.5194/bg-17-3923-2020, https://doi.org/10.5194/bg-17-3923-2020, 2020
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Ocean acidification is the process by which the oceans are changing due to carbon dioxide emissions from human activities. Studying this process in the Arctic Ocean is essential as this ocean and its ecosystems are more vulnerable to the effects of acidification. Water chemistry measurements made in recent years show that waters in and around the Canadian Arctic Archipelago are considerably affected by this process and show dynamic conditions that might have an impact on local marine organisms.
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
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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.
Louise Delaigue, Helmuth Thomas, and Alfonso Mucci
Biogeosciences, 17, 547–566, https://doi.org/10.5194/bg-17-547-2020, https://doi.org/10.5194/bg-17-547-2020, 2020
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This paper reports on the first compilation and analysis of the surface water pCO2 distribution in the Saguenay Fjord, the southernmost subarctic fjord in the Northern Hemisphere, and thus fills a significant knowledge gap in current regional estimates of estuarine CO2 emissions.
Franziska Koebsch, Matthias Winkel, Susanne Liebner, Bo Liu, Julia Westphal, Iris Schmiedinger, Alejandro Spitzy, Matthias Gehre, Gerald Jurasinski, Stefan Köhler, Viktoria Unger, Marian Koch, Torsten Sachs, and Michael E. Böttcher
Biogeosciences, 16, 1937–1953, https://doi.org/10.5194/bg-16-1937-2019, https://doi.org/10.5194/bg-16-1937-2019, 2019
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In natural coastal wetlands, high supplies of marine sulfate suppress methane production. We found these natural methane suppression mechanisms to be suspended by humane interference in a brackish wetland. Here, diking and freshwater rewetting had caused an efficient depletion of the sulfate reservoir and opened up favorable conditions for an intensive methane production. Our results demonstrate how human disturbance can turn coastal wetlands into distinct sources of the greenhouse gas methane.
Rachel M. Horwitz, Alex E. Hay, William J. Burt, Richard A. Cheel, Joseph Salisbury, and Helmuth Thomas
Biogeosciences, 16, 605–616, https://doi.org/10.5194/bg-16-605-2019, https://doi.org/10.5194/bg-16-605-2019, 2019
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High-frequency CO2 measurements are used to quantify the daily and tidal cycles of dissolved carbon in the Bay of Fundy – home to the world's largest tides. The oscillating tidal flows drive a net carbon transport, and these results suggest that previously unaccounted for tidal variation could substantially modulate the coastal ocean's response to global ocean acidification. Evaluating the impact of rising atmospheric CO2 on coastal systems requires understanding this short-term variability.
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
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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.
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
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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.
Johannes Pätsch, Wilfried Kühn, and Katharina Dorothea Six
Biogeosciences, 15, 3293–3309, https://doi.org/10.5194/bg-15-3293-2018, https://doi.org/10.5194/bg-15-3293-2018, 2018
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Biogeochemical shelf sea modelling has a long tradition. Most models include early diagenesis sediment modules for remineralization of organic matter. The model presented here also simulates alkalinity, which is exported into the pelagic system. There the produced alkalinity joins in the carbonate system and is able to buffer invading atmospheric CO2. The input of nitrate via rivers stimulates alkalinity generation within the sediment, which in turn reduces the acidification of coastal areas.
Jonathan Lemay, Helmuth Thomas, Susanne E. Craig, William J. Burt, Katja Fennel, and Blair J. W. Greenan
Biogeosciences, 15, 2111–2123, https://doi.org/10.5194/bg-15-2111-2018, https://doi.org/10.5194/bg-15-2111-2018, 2018
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We report a detailed mechanistic investigation of the impact of Hurricane Arthur on the CO2 cycling on the Scotian Shelf. We can show that in contrast to common thinking, the deepening of the surface during the summer months can lead to increased CO2 uptake as carbon-poor waters from subsurface water are brought up to the surface. Only during prolonged storm events is the deepening of the mixed layer strong enough to bring the (expected) carbon-rich water to the surface.
Sha Ni, Isabelle Taubner, Florian Böhm, Vera Winde, and Michael E. Böttcher
Biogeosciences, 15, 1425–1445, https://doi.org/10.5194/bg-15-1425-2018, https://doi.org/10.5194/bg-15-1425-2018, 2018
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Spirorbis tube worms are common epibionts on brown algae in the Baltic Sea. We made experiments with Spirorbis in the
Kiel Outdoor Benthocosmsat CO2 and temperature conditions predicted for the year 2100. The worms were able to grow tubes even at CO2 levels favouring shell dissolution but did not survive at mean temperatures over 24° C. This indicates that Spirorbis worms will suffer from future excessive ocean warming and from ocean acidification fostering corrosion of their protective tubes.
Jacoba Mol, Helmuth Thomas, Paul G. Myers, Xianmin Hu, and Alfonso Mucci
Biogeosciences, 15, 1011–1027, https://doi.org/10.5194/bg-15-1011-2018, https://doi.org/10.5194/bg-15-1011-2018, 2018
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In the fall of 2014, the upwelling of water from the deep Canada Basin brought water onto the shallower Mackenzie Shelf in the Beaufort Sea. This increased the concentration of CO2 in water on the shelf, which alters pH and changes the transfer of CO2 between the ocean and atmosphere. These findings were a combined result of water sampling for CO2 parameters and the use of a computer model that simulates water movement in the ocean.
Rachel Hussherr, Maurice Levasseur, Martine Lizotte, Jean-Éric Tremblay, Jacoba Mol, Helmuth Thomas, Michel Gosselin, Michel Starr, Lisa A. Miller, Tereza Jarniková, Nina Schuback, and Alfonso Mucci
Biogeosciences, 14, 2407–2427, https://doi.org/10.5194/bg-14-2407-2017, https://doi.org/10.5194/bg-14-2407-2017, 2017
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This study assesses the impact of ocean acidification on phytoplankton and its synthesis of the climate-active gas dimethyl sulfide (DMS), as well as its modulation, by two contrasting light regimes in the Arctic. The light regimes tested had no significant impact on either the phytoplankton or DMS concentration, whereas both variables decreased linearly with the decrease in pH. Thus, a rapid decrease in surface water pH could alter the algal biomass and inhibit DMS production in the Arctic.
William J. Burt, Helmuth Thomas, Lisa A. Miller, Mats A. Granskog, Tim N. Papakyriakou, and Leah Pengelly
Biogeosciences, 13, 4659–4671, https://doi.org/10.5194/bg-13-4659-2016, https://doi.org/10.5194/bg-13-4659-2016, 2016
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This study assesses the state of the carbon cycle in Hudson Bay, an ecologically important region of the Canadian Arctic. Results show that river input, sea-ice melt, biological activity, and general circulation patterns all have significant, and regionally dependent, impacts on the carbon cycle. The study also highlights the importance of detailed sampling procedures in highly stratified waters, and reveals that the deep Hudson Bay is primarily filled with waters of Pacific origin.
Fabian Große, Naomi Greenwood, Markus Kreus, Hermann-Josef Lenhart, Detlev Machoczek, Johannes Pätsch, Lesley Salt, and Helmuth Thomas
Biogeosciences, 13, 2511–2535, https://doi.org/10.5194/bg-13-2511-2016, https://doi.org/10.5194/bg-13-2511-2016, 2016
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We used the ECOHAM5 model to provide a consistent picture of the physical and biological drivers of oxygen deficiency in the North Sea. Regions susceptible to oxygen deficiency are characterised by low tidal mixing and moderate water depth (~ 40 m). Variations in upper layer productivity drive the year-to-year variability of bottom oxygen conditions. The model-based analysis reveals that benthic and pelagic remineralisation account for 90 % of bottom oxygen consumption observed at North Dogger.
N. Jiao, C. Robinson, F. Azam, H. Thomas, F. Baltar, H. Dang, N. J. Hardman-Mountford, M. Johnson, D. L. Kirchman, B. P. Koch, L. Legendre, C. Li, J. Liu, T. Luo, Y.-W. Luo, A. Mitra, A. Romanou, K. Tang, X. Wang, C. Zhang, and R. Zhang
Biogeosciences, 11, 5285–5306, https://doi.org/10.5194/bg-11-5285-2014, https://doi.org/10.5194/bg-11-5285-2014, 2014
M. Dietzel, A. Leis, R. Abdalla, J. Savarino, S. Morin, M. E. Böttcher, and S. Köhler
Biogeosciences, 11, 3149–3161, https://doi.org/10.5194/bg-11-3149-2014, https://doi.org/10.5194/bg-11-3149-2014, 2014
S. E. Craig, H. Thomas, C. T. Jones, W. K. W. Li, B. J. W. Greenan, E. H. Shadwick, and W. J. Burt
Biogeosciences Discuss., https://doi.org/10.5194/bgd-10-11255-2013, https://doi.org/10.5194/bgd-10-11255-2013, 2013
Revised manuscript not accepted
A. Lindenthal, B. Langmann, J. Pätsch, I. Lorkowski, and M. Hort
Biogeosciences, 10, 3715–3729, https://doi.org/10.5194/bg-10-3715-2013, https://doi.org/10.5194/bg-10-3715-2013, 2013
W. J. Burt, H. Thomas, K. Fennel, and E. Horne
Biogeosciences, 10, 53–66, https://doi.org/10.5194/bg-10-53-2013, https://doi.org/10.5194/bg-10-53-2013, 2013
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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.
Weiyi Tang, Jeff Talbott, Timothy Jones, and Bess B. Ward
EGUsphere, https://doi.org/10.5194/egusphere-2024-638, https://doi.org/10.5194/egusphere-2024-638, 2024
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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 treating nitrogen in WWTPs.
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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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.
Amanda Y. L. Cheong, Kogila Vani Annammala, Ee Ling Yong, Yongli Zhou, Robert S. Nichols, and Patrick Martin
EGUsphere, https://doi.org/10.5194/egusphere-2023-2528, https://doi.org/10.5194/egusphere-2023-2528, 2023
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We measured nutrients and dissolved organic matter for one 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 over silicon and phosphorus. Our data help to explain how eutrophication persists in this system.
Marlena Szeligowska, Déborah Benkort, Anna Przyborska, Mateusz Moskalik, Bernabé Moreno, Emilia Trudnowska, and Katarzyna Błachowiak-Samołyk
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-162, https://doi.org/10.5194/bg-2023-162, 2023
Revised manuscript accepted for BG
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European Arctic experiences rapid regional warming resulting in the retreat of glaciers terminating in the sea onto land. Due to this process, area of one of the well-studied fjords, Hornsund, increased by 100 km2 and 38 %. Using improved mathematical model, we estimated that despite some negative consequences of glacial meltwater release such newly ice-free area markedly contribute to atmospheric carbon uptake and become efficient carbon sinks.
Taketoshi Kodama, Atsushi Nishimoto, Ken-ichi Nakamura, Misato Nakae, Naoki Iguchi, Yosuke Igeta, and Yoichi Kogure
Biogeosciences, 20, 3667–3682, https://doi.org/10.5194/bg-20-3667-2023, https://doi.org/10.5194/bg-20-3667-2023, 2023
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Carbon and nitrogen are essential elements for organisms; their stable isotope ratios (13C : 12C, 15N : 14N) are useful tools for understanding turnover and movement in the ocean. In the Sea of Japan, the environment is rapidly being altered by human activities. The 13C : 12C of small organic particles is increased by active carbon fixation, and phytoplankton growth increases the values. The 15N : 14N variations suggest that nitrates from many sources contribute to organic production.
Aaron Ferderer, Kai G. Schulz, Ulf Riebesell, Kirralee G. Baker, Zanna Chase, and Lennart Thomas Bach
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-144, https://doi.org/10.5194/bg-2023-144, 2023
Revised manuscript accepted for BG
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Ocean alkalinity enhancement (OAE) is a promising method of atmospheric carbon removal, however it's 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.
Aubin Thibault de Chanvalon, George W. Luther, Emily R. Estes, Jennifer Necker, Bradley M. Tebo, Jianzhong Su, and Wei-Jun Cai
Biogeosciences, 20, 3053–3071, https://doi.org/10.5194/bg-20-3053-2023, https://doi.org/10.5194/bg-20-3053-2023, 2023
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The intensity of the oceanic trap of CO2 released by anthropogenic activities depends on the alkalinity brought by continental weathering. Between ocean and continent, coastal water and estuaries can limit or favour the alkalinity transfer. This study investigate new interactions between dissolved metals and alkalinity in the oxygen-depleted zone of estuaries.
Joonas J. Virtasalo, Peter Österholm, and Eero Asmala
Biogeosciences, 20, 2883–2901, https://doi.org/10.5194/bg-20-2883-2023, https://doi.org/10.5194/bg-20-2883-2023, 2023
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We mixed acidic metal-rich river water from acid sulfate soils and seawater in the laboratory to study the flocculation of dissolved metals and organic matter in estuaries. Al and Fe flocculated already at a salinity of 0–2 to large organic flocs (>80 µm size). Precipitation of Al and Fe hydroxide flocculi (median size 11 µm) began when pH exceeded ca. 5.5. Mn transferred weakly to Mn hydroxides and Co to the flocs. Up to 50 % of Cu was associated with the flocs, irrespective of seawater mixing.
Moritz Baumann, Allanah Joy Paul, Jan Taucher, Lennart Thomas Bach, Silvan Goldenberg, Paul Stange, Fabrizio Minutolo, and Ulf Riebesell
Biogeosciences, 20, 2595–2612, https://doi.org/10.5194/bg-20-2595-2023, https://doi.org/10.5194/bg-20-2595-2023, 2023
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The sinking velocity of marine particles affects how much atmospheric CO2 is stored inside our oceans. We measured particle sinking velocities in the Peruvian upwelling system and assessed their physical and biochemical drivers. We found that sinking velocity was mainly influenced by particle size and porosity, while ballasting minerals played only a minor role. Our findings help us to better understand the particle sinking dynamics in this highly productive marine system.
Kyle E. Hinson, Marjorie A. M. Friedrichs, Raymond G. Najjar, Maria Herrmann, Zihao Bian, Gopal Bhatt, Pierre St-Laurent, Hanqin Tian, and Gary Shenk
Biogeosciences, 20, 1937–1961, https://doi.org/10.5194/bg-20-1937-2023, https://doi.org/10.5194/bg-20-1937-2023, 2023
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Climate impacts are essential for environmental managers to consider when implementing nutrient reduction plans designed to reduce hypoxia. This work highlights relative sources of uncertainty in modeling regional climate impacts on the Chesapeake Bay watershed and consequent declines in bay oxygen levels. The results demonstrate that planned water quality improvement goals are capable of reducing hypoxia levels by half, offsetting climate-driven impacts on terrestrial runoff.
Linquan Mu, Jaime B. Palter, and Hongjie Wang
Biogeosciences, 20, 1963–1977, https://doi.org/10.5194/bg-20-1963-2023, https://doi.org/10.5194/bg-20-1963-2023, 2023
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Enhancing ocean alkalinity accelerates carbon dioxide removal from the atmosphere. We hypothetically added alkalinity to the Amazon River and examined the increment of the carbon uptake by the Amazon plume. We also investigated the minimum alkalinity addition in which this perturbation at the river mouth could be detected above the natural variability.
Karl M. Attard, Anna Lyssenko, and Iván F. Rodil
Biogeosciences, 20, 1713–1724, https://doi.org/10.5194/bg-20-1713-2023, https://doi.org/10.5194/bg-20-1713-2023, 2023
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Aquatic plants produce a large amount of organic matter through photosynthesis that, following erosion, is deposited on the seafloor. In this study, we show that plant detritus can trigger low-oxygen conditions (hypoxia) in shallow coastal waters, making conditions challenging for most marine animals. We propose that the occurrence of hypoxia may be underestimated because measurements typically do not consider the region closest to the seafloor, where detritus accumulates.
M. James McLaughlin, Cindy Bessey, Gary A. Kendrick, John Keesing, and Ylva S. Olsen
Biogeosciences, 20, 1011–1026, https://doi.org/10.5194/bg-20-1011-2023, https://doi.org/10.5194/bg-20-1011-2023, 2023
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Coral reefs face increasing pressures from environmental change at present. The coral reef framework is produced by corals and calcifying algae. The Kimberley region of Western Australia has escaped land-based anthropogenic impacts. Specimens of the dominant coral and algae were collected from Browse Island's reef platform and incubated in mesocosms to measure calcification and production patterns of oxygen. This study provides important data on reef building and climate-driven effects.
Patricia Ayón Dejo, Elda Luz Pinedo Arteaga, Anna Schukat, Jan Taucher, Rainer Kiko, Helena Hauss, Sabrina Dorschner, Wilhelm Hagen, Mariona Segura-Noguera, and Silke Lischka
Biogeosciences, 20, 945–969, https://doi.org/10.5194/bg-20-945-2023, https://doi.org/10.5194/bg-20-945-2023, 2023
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Ocean upwelling regions are highly productive. With ocean warming, severe changes in upwelling frequency and/or intensity and expansion of accompanying oxygen minimum zones are projected. In a field experiment off Peru, we investigated how different upwelling intensities affect the pelagic food web and found failed reproduction of dominant zooplankton. The changes projected could severely impact the reproductive success of zooplankton communities and the pelagic food web in upwelling regions.
Mathilde Jutras, Alfonso Mucci, Gwenaëlle Chaillou, William A. Nesbitt, and Douglas W. R. Wallace
Biogeosciences, 20, 839–849, https://doi.org/10.5194/bg-20-839-2023, https://doi.org/10.5194/bg-20-839-2023, 2023
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The deep waters of the lower St Lawrence Estuary and gulf have, in the last decades, experienced a strong decline in their oxygen concentration. Below 65 µmol L-1, the waters are said to be hypoxic, with dire consequences for marine life. We show that the extent of the hypoxic zone shows a seven-fold increase in the last 20 years, reaching 9400 km2 in 2021. After a stable period at ~ 65 µmol L⁻¹ from 1984 to 2019, the oxygen level also suddenly decreased to ~ 35 µmol L-1 in 2020.
Sachi Umezawa, Manami Tozawa, Yuichi Nosaka, Daiki Nomura, Hiroji Onishi, Hiroto Abe, Tetsuya Takatsu, and Atsushi Ooki
Biogeosciences, 20, 421–438, https://doi.org/10.5194/bg-20-421-2023, https://doi.org/10.5194/bg-20-421-2023, 2023
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We conducted repetitive observations in Funka Bay, Japan, during the spring bloom 2019. We found nutrient concentration decreases in the dark subsurface layer during the bloom. Incubation experiments confirmed that diatoms could consume nutrients at a substantial rate, even in darkness. We concluded that the nutrient reduction was mainly caused by nutrient consumption by diatoms in the dark.
Dirk Jong, Lisa Bröder, Tommaso Tesi, Kirsi H. Keskitalo, Nikita Zimov, Anna Davydova, Philip Pika, Negar Haghipour, Timothy I. Eglinton, and Jorien E. Vonk
Biogeosciences, 20, 271–294, https://doi.org/10.5194/bg-20-271-2023, https://doi.org/10.5194/bg-20-271-2023, 2023
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With this study, we want to highlight the importance of studying both land and ocean together, and water and sediment together, as these systems function as a continuum, and determine how organic carbon derived from permafrost is broken down and its effect on global warming. Although on the one hand it appears that organic carbon is removed from sediments along the pathway of transport from river to ocean, it also appears to remain relatively ‘fresh’, despite this removal and its very old age.
Georgia Filippi, Manos Dassenakis, Vasiliki Paraskevopoulou, and Konstantinos Lazogiannis
Biogeosciences, 20, 163–189, https://doi.org/10.5194/bg-20-163-2023, https://doi.org/10.5194/bg-20-163-2023, 2023
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The pollution of the western Saronikos Gulf from heavy metals has been examined through the study of marine sediment cores. It is a deep gulf (maximum depth 440 m) near Athens affected by industrial and volcanic activity. Eight cores were received from various stations and depths and analysed for their heavy metal content and geochemical characteristics. The results were evaluated by using statistical methods, environmental indicators and comparisons with old data.
Jing He and Michael D. Tyka
Biogeosciences, 20, 27–43, https://doi.org/10.5194/bg-20-27-2023, https://doi.org/10.5194/bg-20-27-2023, 2023
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Recently, ocean alkalinity enhancement (OAE) has gained interest as a scalable way to address the urgent need for negative CO2 emissions. In this paper we examine the capacity of different coastlines to tolerate alkalinity enhancement and the time scale of CO2 uptake following the addition of a given quantity of alkalinity. The results suggest that OAE has significant potential and identify specific favorable and unfavorable coastlines for its deployment.
Arnaud Laurent, Haiyan Zhang, and Katja Fennel
Biogeosciences, 19, 5893–5910, https://doi.org/10.5194/bg-19-5893-2022, https://doi.org/10.5194/bg-19-5893-2022, 2022
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The Changjiang is the main terrestrial source of nutrients to the East China Sea (ECS). Nutrient delivery to the ECS has been increasing since the 1960s, resulting in low oxygen (hypoxia) during phytoplankton decomposition in summer. River phosphorus (P) has increased less than nitrogen, and therefore, despite the large nutrient delivery, phytoplankton growth can be limited by the lack of P. Here, we investigate this link between P limitation, phytoplankton production/decomposition, and hypoxia.
Coline Poppeschi, Guillaume Charria, Anne Daniel, Romaric Verney, Peggy Rimmelin-Maury, Michaël Retho, Eric Goberville, Emilie Grossteffan, and Martin Plus
Biogeosciences, 19, 5667–5687, https://doi.org/10.5194/bg-19-5667-2022, https://doi.org/10.5194/bg-19-5667-2022, 2022
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This paper aims to understand interannual changes in the initiation of the phytoplankton growing period (IPGP) in the current context of global climate changes over the last 20 years. An important variability in the timing of the IPGP is observed with a trend towards a later IPGP during this last decade. The role and the impact of extreme events (cold spells, floods, and wind burst) on the IPGP is also detailed.
Lin Yang, Jing Zhang, Anja Engel, and Gui-Peng Yang
Biogeosciences, 19, 5251–5268, https://doi.org/10.5194/bg-19-5251-2022, https://doi.org/10.5194/bg-19-5251-2022, 2022
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Enrichment factors of dissolved organic matter (DOM) in the eastern marginal seas of China exhibited a significant spatio-temporal variation. Photochemical and enrichment processes co-regulated DOM enrichment in the sea-surface microlayer (SML). Autochthonous DOM was more frequently enriched in the SML than terrestrial DOM. DOM in the sub-surface water exhibited higher aromaticity than that in the SML.
Mona Norbisrath, Johannes Pätsch, Kirstin Dähnke, Tina Sanders, Gesa Schulz, Justus E. E. van Beusekom, and Helmuth Thomas
Biogeosciences, 19, 5151–5165, https://doi.org/10.5194/bg-19-5151-2022, https://doi.org/10.5194/bg-19-5151-2022, 2022
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Total alkalinity (TA) regulates the oceanic storage capacity of atmospheric CO2. TA is also metabolically generated in estuaries and influences coastal carbon storage through its inflows. We used water samples and identified the Hamburg port area as the one with highest TA generation. Of the overall riverine TA load, 14 % is generated within the estuary. Using a biogeochemical model, we estimated potential effects on the coastal carbon storage under possible anthropogenic and climate changes.
Le Zhang and Z. George Xue
Biogeosciences, 19, 4589–4618, https://doi.org/10.5194/bg-19-4589-2022, https://doi.org/10.5194/bg-19-4589-2022, 2022
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We adopt a high-resolution carbon model for the Gulf of Mexico (GoM) and calculate the decadal trends of important carbon system variables in the GoM from 2001 to 2019. The GoM surface CO2 values experienced a steady increase over the past 2 decades, and the ocean surface pH is declining. Although carbonate saturation rates remain supersaturated with aragonite, they show a slightly decreasing trend. The northern GoM is a stronger carbon sink than we thought.
Michael M. Whitney
Biogeosciences, 19, 4479–4497, https://doi.org/10.5194/bg-19-4479-2022, https://doi.org/10.5194/bg-19-4479-2022, 2022
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Coastal hypoxia is a major environmental problem of increasing severity. The 21st-century projections analyzed indicate global coastal waters will warm and experience rapid declines in oxygen. The forecasted median coastal trends for increasing sea surface temperature and decreasing oxygen capacity are 48 % and 18 % faster than the rates observed over the last 4 decades. Existing hypoxic areas are expected to worsen, and new hypoxic areas likely will emerge under these warming-related pressures.
Bryce Van Dam, Nele Lehmann, Mary A. Zeller, Andreas Neumann, Daniel Pröfrock, Marko Lipka, Helmuth Thomas, and Michael Ernst Böttcher
Biogeosciences, 19, 3775–3789, https://doi.org/10.5194/bg-19-3775-2022, https://doi.org/10.5194/bg-19-3775-2022, 2022
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We quantified sediment–water exchange at shallow sites in the North and Baltic seas. We found that porewater irrigation rates in the former were approximately twice as high as previously estimated, likely driven by relatively high bioirrigative activity. In contrast, we found small net fluxes of alkalinity, ranging from −35 µmol m−2 h−1 (uptake) to 53 µmol m−2 h−1 (release). We attribute this to low net denitrification, carbonate mineral (re-)precipitation, and sulfide (re-)oxidation.
Jiaying Abby Guo, Robert Strzepek, Anusuya Willis, Aaron Ferderer, and Lennart Thomas Bach
Biogeosciences, 19, 3683–3697, https://doi.org/10.5194/bg-19-3683-2022, https://doi.org/10.5194/bg-19-3683-2022, 2022
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Ocean alkalinity enhancement is a CO2 removal method with significant potential, but it can lead to a perturbation of the ocean with trace metals such as nickel. This study tested the effect of increasing nickel concentrations on phytoplankton growth and photosynthesis. We found that the response to nickel varied across the 11 phytoplankton species tested here, but the majority were rather insensitive. We note, however, that responses may be different under other experimental conditions.
Malcolm E. Scully, W. Rockwell Geyer, David Borkman, Tracy L. Pugh, Amy Costa, and Owen C. Nichols
Biogeosciences, 19, 3523–3536, https://doi.org/10.5194/bg-19-3523-2022, https://doi.org/10.5194/bg-19-3523-2022, 2022
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For two consecutive summers, the bottom waters in southern Cape Cod Bay became severely depleted of dissolved oxygen. Low oxygen levels in bottom waters have never been reported in this area before, and this unprecedented occurrence is likely the result of a new algae species that recently began blooming during the late-summer months. We present data suggesting that blooms of this new species are the result of regional climate change including warmer waters and changes in summer winds.
Cited articles
2008/56/Ec: M. Commission of the European Communities Directive 2008/56/EC of the European Parliament and of the Council of 17 June 2008. Establishing a Framework for Community Action in the Field of Marine Environmental Policy (Marine Strategy Framework Directive), Official Journal of the European Union L 164, 2008.
Akam, S. A., Coffin, R. B., Abdulla, H. A. N., and Lyons T. W.: Dissolved
inorganic carbon pump in methane-charged shallow marine sediments: State of
the art and new model perspectives, Front. Mar. Sci., 7, 206, https://doi.org/10.3389/FMARS.2020.00206, 2020.
Al-Raei, A. M., Bosselmann, K., Böttcher, M. E., Hespenheide, B.,
and Tauber, F.: Seasonal dynamics of microbial sulfate reduction in
temperate intertidal surface sediments: Controls by temperature and organic
matter, Ocean Dynam., 59, 351–370, 2009.
Amann, T., Weiss, A., and Hartmann, J.: Inorganic Carbon Fluxes in the Inner
Elbe Estuary, Germany, Estuar. Coast., 38, 192–210,
https://doi.org/10.1007/s12237-014-9785-6, 2015.
Artioli, Y., Blackford, J. C., Butenschön, M., Holt, J. T., Wakelin, S.
L., Thomas, H., Borges, A. V., and Allen, J. I.: The carbonate system in the
North Sea: Sensitivity and model validation, J. Marine Syst.,
102–104, 1–13, https://doi.org/10.1016/j.jmarsys.2012.04.006, 2012.
Backhaus, J. O.: A three-dimensional model for the simulation of shelf sea
dynamics, Ocean Dynam., 38, 165–187, https://doi.org/10.1016/0278-4343(84)90044-X,
1985.
Backhaus, J. O. and Hainbucher, D.: A finite difference general circulation
model for shelf seas and its application to low frequency variability on the
North European Shelf, Elsev. Oceanogr. Serie., 45, 221–244,
https://doi.org/10.1016/S0422-9894(08)70450-1, 1987.
Ben-Yaakov, S.: pH BUFFERING OF PORE WATER OF RECENT ANOXIC MARINE
SEDIMENTS, Limnol. Oceanogr., 18, 86–94, https://doi.org/10.4319/lo.1973.18.1.0086,
1973.
Berner, R. A., Scott, M. R., and Thomlinson, C.: Carbonate alkalinity in the
pore waters of anoxic marine sediments, Limnol. Oceanogr., 15,
544–549, https://doi.org/10.4319/lo.1970.15.4.0544, 1970.
Billerbeck, M., Werner, U., Polerecky, L., Walpersdorf, E., de Beer, D., and
Hüttel, M.: Surficial and deep pore water circulation governs spatial
and temporal scales of nutrient recycling in intertidal sand flat sediment,
Mar. Ecol.-Prog. Ser., 326, 61–76, 2006.
Böttcher, M. E., Hespenheide, B., Brumsack, H.-J., and Bosselmann, K.:
Stable isotope biogeochemistry of the sulfur cycle in modern marine
sediments: I. Seasonal dynamics in a temperate intertidal sandy surface
sediment, Isotopes Environ. Health Stud., 40, 267–283, 2004.
Böttcher, M. E., Al-Raei, A. M., Hilker, Y., Heuer, V., Hinrichs, K.-U.,
and Segl, M.: Methane and organic matter as sources for excess carbon
dioxide in intertidal surface sands: Biogeochemical and stable isotope
evidence, Geochim. Cosmochim. Ac., 71, A111, https://doi.org/10.1016/j.gca.2007.06.012, 2007.
Borges, A. V.: Present day carbon dioxide fluxes in the coastal ocean and
possible feedbacks under global change, in: Oceans and the atmospheric carbon
content, edited by: da Silva Duarte, P. M. Santana Casiano, J. M., Chapter 3,
47–77, https://doi.org/10.1007/978-90-481-9821-4, Springer, Dordrecht, Heidelberg, London, New York, 2011.
Borges, A. V. and Gypens, N.: Corbonate chemistry in the coastal zone
responds more strongly to eutrophication than to ocean acidification,
Limnol. Oceanogr., 55, 346–353, 2010.
Brasse, J., Reimer, A., Seifert, R., and Michaelis, W.: The influence of
intertidal mudflats on the dissolved inorganic carbon and total alkalinity
distribution in the German Bight, southeastern North Sea, J. Sea Res., 42,
93–103, https://doi.org/10.1016/S1385-1101(99)00020-9, 1999.
Brenner, H., Braeckman, U., Le Guitton, M., and Meysman, F. J. R.: The impact of sedimentary alkalinity release on the water column CO2 system in the North Sea, Biogeosciences, 13, 841–863, https://doi.org/10.5194/bg-13-841-2016, 2016.
Burt, W. J., Thomas, H., Pätsch, J., Omar, A. M., Schrum, C., Daewel,
U., Brenner, H., and de Baar, H. J. W.: Radium isotopes as a tracer of
sediment-water column exchange in the North Sea, Global Biogeochem.
Cy., 28, 19, https://doi.org/10.1002/2014GB004825, 2014.
Burt, W. J., Thomas, H., Hagens, M., Pätsch, J., Clargo, N. M., Salt, L.
A., Winde, V., and Böttcher, M. E.: Carbon sources in the North Sea
evaluated by means of radium and stable carbon isotope tracers, Limnol.
Oceanogr., 61, 666–683, https://doi.org/10.1002/lno.10243, 2016.
Cadée, G. C. and Hegeman, J.: Phytoplankton in the Marsdiep at the end
of the 20th century; 30 years monitoring biomass, primary production,
and Phaeocystis blooms, J. Sea Res., 48, 97–110,
https://doi.org/10.1016/S1385-1101(02)00161-2, 2002.
Cai, W.-J., Hu, X., Huang, W.-J., Jiang, L.-Q., Wang, Y., Peng, T.-H., and
Zhang, X.: Surface ocean alkalinity distribution in the western North
Atlantic Ocean margins, J. Geophys. Res., 115, C08014,
https://doi.org/10.1029/2009JC005482, 2010.
Carvalho, A. C. O., Marins, R. V., Dias, F. J. S., Rezende, C. E.,
Lefèvre, N., Cavalcante, M. S., and Eschrique, S. A.: Air-sea CO2 fluxes for the Brazilian northeast continental shelf in a climatic
transition region, J. Marine Syst., 173, 70–80,
https://doi.org/10.1016/j.jmarsys.2017.04.009, 2017.
Chambers, R. M., Hollibaugh, J. T., and Vink, S. M.: Sulfate reduction and
sediment metabolism in Tomales Bay, California, Biogeochemistry, 25, 1–18,
https://doi.org/10.1007/BF00000509, 1994.
Chen, C., Liu, H., and Beardsley, R. C.: An Unstructured Grid,
Finite-Volume, Three-Dimensional, Primitive Equations Ocean Model:
Application to Coastal Ocean and Estuaries, J. Atmos. Ocean. Tech., 20,
159–186,
https://doi.org/10.1175/1520-0426(2003)020<0159:AUGFVT>2.0.CO;2,
2003.
Chen, C.-T. A. and Wang, S.-L.: Carbon, alkalinity and nutrient budgets on
the East China Sea continental shelf, J. Geophys. Res., 104,
20675–20686, https://doi.org/10.1029/1999JC900055, 1999.
CPSL: Final Report of the Trilateral Working Group on Coastal Protection and
Sea Level Rise, Wadden Sea Ecosystem No. 13, Common Wadden Sea Secretariat,
Wilhelmshaven, Germany, 2001.
de Beer, D., Wenzhöfer, F., Ferdelman, T. G., Boehme, S., Huettel, M.,
van Beusekom, J., Böttcher, M. E., Musat, N., and Dubilier, N.: Transport and
mineralization rates in North Sea sandy intertidal sediments
(Sylt-Rømø Basin, Waddensea), Limnol. Oceanogr., 50, 113–127, 2005.
Dickson, A. G., Afghan, J. D., and Anderson, G. C.: Reference materials for oceanic
CO2 analysis: a method for the certification of total alkalinity,
Mar. Chem., 80, 185–197, 2003.
Dollar, S. J., Smith, S. V., Vink, S. M., Obrebski, S., and Hollibaugh,
J. T.: Annual cycle of benthic nutrient fluxes in Tomales Bay, California,
and contribution of the benthos to total ecosystem metabolism, Mar. Ecol.-Prog. Ser., 79, 115–125, https://doi.org/10.3354/meps079115, 1991.
Duarte, C. M., Hendriks, I. E., Moore, T. S., Olsen, Y. S., Steckbauer, A.,
Ramajo, L., Carstensen, J., Trotter, J. A., and McCulloch, M.: Is Ocean
Acidification an Open-Ocean Syndrome? Understanding Anthropogenic Impacts on
Seawater pH, Estuar. Coast., 36, 221–236, 2013.
EEA: Waterbase – Rivers, available at: https://data.europa.eu/euodp/de/data/dataset/data_waterbase-rivers-7, last access: 20 August 2020.
Ehlers, J.: Geomorphologie und Hydrologie des Wattenmeeres, in: Warnsignale aus dem
Wattenmeer, edited by: Lozan, J. L.,
Rachor, E., Von Westernhagen, H., Lenz, W., Blackwell Wissenschaftsverlag, Berlin, 1–11, 1994.
Faneca Sànchez, M., Gunnink, J. L., van Baaren, E. S., Oude Essink, G. H. P., Siemon, B., Auken, E., Elderhorst, W., and de Louw, P. G. B.: Modelling climate change effects on a Dutch coastal groundwater system using airborne electromagnetic measurements, Hydrol. Earth Syst. Sci., 16, 4499–4516, https://doi.org/10.5194/hess-16-4499-2012, 2012.
Flemming, B. W. and Davis, R. A. J.: Holocene evolution, morphodynamics and
sedimentology of the Spiekeroog barrier island system (southern North Sea),
Senck. Marit., 25, 117–155, 1994.
Grashorn, S., Lettmann, K. A., Wolff, J.-O., Badewien, T. H., and Stanev, E.
V.: East Frisian Wadden Sea hydrodynamics and wave effects in an
unstructured-grid model, Ocean Dynam., 65, 419–434,
https://doi.org/10.1007/s10236-014-0807-5, 2015.
Große, F., Kreus, M., Lenhart, H.-J., Pätsch, J., and Pohlmann, T.: A
Novel Modeling Approach to Quantify the Influence of Nitrogen Inputs on the
Oxygen Dynamics of the North Sea, Front. Mar. Sci., 4, 21 pp.,
https://doi.org/10.3389/fmars.2017.00383, 2017.
Gustafsson, E., Hagens, M., Sun, X., Reed, D. C., Humborg, C., Slomp, C. P., and Gustafsson, B. G.: Sedimentary alkalinity generation and long-term alkalinity development in the Baltic Sea, Biogeosciences, 16, 437–456, https://doi.org/10.5194/bg-16-437-2019, 2019.
HASEC: OSPAR Convention for the Protection of the Marine Environment of the
North-East Atlantic, Meeting of the Hazardous Substances and Eutrophication
Committee (HASEC), Oslo 27 February–2 March 2012, available at: https://www.ospar.org/meetings/archive?q=2012 (last access: 20 August 2020), 2012.
Hild, A.: Geochemie der Sedimente und Schwebstoffe im Rückseitenwatt von
Spiekeroog und ihre Beeinflussung durch biologische Aktivität,
Forschungszentrum Terramare Berichte, 5, 71 pp., Tectum Verlag, Marburg, 1997.
Höpner, T. and Michaelis, H.: Sogenannte “Schwarze
Flecken” – ein Eutrophierungssymptom des Wattenmeeres, in: Warnsignale aus dem
Wattenmeer, edited by: Lozán, L.,
Rachor, E., Reise, K., von Westernhagen, H., und Lenz, W., Blackwell, Berlin, 153–159, 1994.
Hoppema, J. M. J.: The distribution and seasonal variation of alkalinity in
the southern bight of the North Sea and in the western Wadden Sea,
Neth. J. Sea Res., 26, 11–23, https://doi.org/10.1016/0077-7579(90)90053-J, 1990.
Hu, X. and Cai, W.-J.: An assessment of ocean margin anaerobic processes on
oceanic alkalinity budget, Global Biogeochem. Cy., 25, 1–11, 2011.
Johannsen, A., Dähnke, K., and Emeis, K.-C.: Isotopic composition of
nitrate in five German rivers discharging into the North Sea, Org.
Geochem., 39, 1678–1689 https://doi.org/10.1016/j.orggeochem.2008.03.004, 2008.
Johnson, K. M., Wills, K. D., Buttler, D. B., Johnson, W. K., and Wong, C. S.:
Coulometric total carbon dioxide analysis for marine studies: maximizing the
performance of an automated gas extraction system and coulometric detector,
Mar. Chem., 44, 167–187, 1993.
Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D., Gandin, L.,
Iredell, M., Saha S., White, G., Woollen, J., Zhu, Y., Chelliah, M.,
Ebisuzaki, W., Higgins, W., Janowiak, J., Mo, K. C., Ropelewski, C., Wang,
J., Leetmaa, A., Reynolds, R., Jenne, R., and Joseph, D.: The NCEP/NCAR
40-year reanalysis project, B. Am. Meteorol. Soc.,
77, 437–471,
https://doi.org/10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2, 1996.
Kempe, S. and Pegler, K.: Sinks and sources of CO2 in coastal seas: the
North Sea, Tellus B, 43, 224–235, https://doi.org/10.3402/tellusb.v43i2.15268, 1991.
Kerimoglu, O., Große, F., Kreus, M., Lenhart, H.-J., and van Beusekom,
J. E. E.: A model-based projection of historical state of a coastal
ecosystem: Relevance of phytoplankton stoichiometry, Sci. Total
Environ., 639, 1311–1323, https://doi.org/10.1016/j.scitotenv.2018.05.215, 2018.
Kohlmeier, C. and Ebenhöh, W.: Modelling the biogeochemistry of a tidal
flat ecosystem with EcoTiM, Ocean Dynam., 59, 393–415, https://doi.org/10.1007/s10236-009-0188-3, 2009.
Kühn, W., Pätsch, J., Thomas, H., Borges, A. V., Schiettecatte,
L.-S., Bozec, Y., and Prowe, A. E. F.: Nitrogen and carbon cycling in the
North Sea and exchange with the North Atlantic-A model study, Part II:
Carbon budget and fluxes, Cont. Shelf Res., 30, 1701–1716,
https://doi.org/10.1016/j.csr.2010.07.001, 2010.
Laruelle, G. G., Lauerwald, R., Pfeil, B., and Regnier, P.: Regionalized
global budget of the CO2 exchange at the air-water interface in
continental shelf seas, Global Biogeochem. Cy., 28, 1199–1214,
https://doi.org/10.1002/2014gb004832, 2014.
Lenhart, H.-J., Radach, G., Backhaus, J. O., and Pohlmann, T.: Simulations
of the North Sea circulation, its variability, and its implementation as
hydrodynamical forcing in ERSEM, Neth. J. Sea Res., 33, 271–299,
https://doi.org/10.1016/0077-7579(95)90050-0, 1995.
Lettmann, K. A., Wolff, J.-O., and Badewien, T. H.: Modeling the impact of
wind and waves on suspended particulate matter fluxes in the East Frisian
Wadden Sea (southern North Sea), Ocean Dynam., 59, 239–262, https://doi.org/10.1007/s10236-009-0194-5, 2009.
Lipinski, M.: Nährstoffelemente und Spurenmetalle in Wasserproben der
Hunte und Jade, Diploma thesis, C.v.O. University of Oldenburg, 82 pp.,
1999.
Lorkowski, I., Pätsch, J., Moll, A., and Kühn, W.: Interannual
variability of carbon fluxes in the North Sea from 1970 to 2006 – Competing
effects of abiotic and biotic drivers on the gas-exchange of CO2, Estuar.
Coast. Shelf S., 100, 38–57, https://doi.org/10.1016/j.ecss.2011.11.037, 2012.
Łukawska-Matuszewska, K. and Graca, B.: Pore water alkalinity below the
permanent halocline in the Gdańsk Deep (Baltic Sea) – Concentration
variability and benthic fluxes, Mar. Chem., 204, 49–61, 2017.
Mayer, B., Rixen, T., and Pohlmann, T.: The Spatial and Temporal Variability
of Air-Sea CO2 Fluxes and the Effect of Net Coral Reef Calcification in the
Indonesian Seas: A Numerical Sensitivity Study, Front. Mar. Sci.,
5, https://doi.org/10.3389/fmars.2018.00116, 2018.
McQuatters-Gollop, A. and Vermaat, J. E.: Covariance among North Sea
ecosystem state indicators during the past 50 years e contrasts between
coastal and open waters, J. Sea Res., 65, 284–292,
https://doi.org/10.1016/j.seares.2010.12.004, 2011.
McQuatters-Gollop, A., Raitsos, D. E., Edwards, M., Pradhan, Y., Mee, L. D.,
Lavender, S. J., and Attrill, M. J.: A long-term chlorophyll data set
reveals regime shift in North Sea phytoplankton biomass unconnected to
nutrient trends, Limnol. Oceanogr., 52, 635–648,
https://doi.org/10.4319/lo.2007.52.2.0635, 2007.
Moore, W. S., Beck, M., Riedel, T., Rutgers van der Loeff, M., Dellwig, O.,
Shaw, T. J., Schnetger, B., and Brumsack, H.-J.: Radium-based pore water
fluxes of silica, alkalinity, manganese, DOC, and uranium: A decade of
studies in the German Wadden Sea, Geochim. Cosmochim. Ac., 75, 6535–6555, https://doi.org/10.1016/j.gca.2011.08.037, 2011.
Neal, C.: Calcite saturation in eastern UK rivers, Sci Total
Environ., 282–283, 311–326, https://doi.org/10.1016/S0048-9697(01)00921-4, 2002.
Neira, C. and Rackemann, M.: Black spots produced by buried macroalgae in
intertidal sandy sediments of the Wadden Sea: Effects on the meiobenthos, J.
Sea Res., 36, 153–170, 1996.
NOAA: Physical Sciences Laboratory (PSL), available at: https://psl.noaa.gov/, last access: 20 August 2020.
Onken, R. and Riethmüller, R.: Determination of the freshwater budget
of tidal flats from measurements near a tidal inlet, Cont. Shelf
Res., 30, 924–933, https://doi.org/10.1016/j.csr.2010.02.004, 2010.
Otto, L., Zimmerman, J. T. F., Furnes, G. K., Mork, M., Saetre, R., and Becker,
G.: Review of the physical oceanography of the North Sea, Neth.
J. Sea Res., 26, 161–238,
https://doi.org/10.1016/0077-7579(90)90091-T, 1990.
Pätsch, J. and Kühn, W.: Nitrogen and carbon cycling in the North
Sea and exchange with the North Atlantic – a model study Part I: Nitrogen
budget and fluxes, Cont. Shelf Res., 28, 767–787, https://doi.org/10.1016/j.csr.2007.12.013, 2008.
Pätsch, J. and Lenhart, H.-J.: Daily Loads of Nutrients, Total
Alkalinity, Dissolved Inorganic Carbon and Dissolved Organic Carbon of the
European Continental Rivers for the Years 1977–2006, Berichte aus dem
Zentrum für Meeres- und Klimaforschung, available at:
https://wiki.cen.uni-hamburg.de/ifm/ECOHAM/DATA_RIVER (last access: 22 January 2019),
2008.
Pätsch, J., Serna, A., Dähnke, K., Schlarbaum, T., Johannsen, A.,
and Emeis, K.-C.: Nitrogen cycling in the German Bight (SE North Sea) –
Clues from modelling stable nitrogen isotopes, Cont. Shelf Res.,
30, 203–213, https://doi.org/10.1016/j.csr.2009.11.003, 2010.
Pätsch, J., Burchard, H., Dieterich, C., Gräwe, U., Gröger, M.,
Mathis, M., Kapitza, H., Bersch, M., Moll, A., Pohlmann, T., Su, J.,
Ho-Hagemann, H. T. M., Schulz, A., Elizalde, A., and Eden, C.: An evaluation
of the North Sea circulation in global and regional models relevant for
ecosystem simulations, Ocean Model., 116, 70–95,
https://doi.org/10.1016/j.ocemod.2017.06.005, 2017.
Pätsch, J., Kühn, W., and Six, K. D.: Interannual sedimentary effluxes of alkalinity in the southern North Sea: model results compared with summer observations, Biogeosciences, 15, 3293–3309, https://doi.org/10.5194/bg-15-3293-2018, 2018.
Pohlmann, T.: Predicting the thermocline in a circulation model of the North
Sea – Part I: model description, calibration and verification, Cont.
Shelf Res., 16, 131–146, https://doi.org/10.1016/0278-4343(95)90885-S, 1996.
Provoost, P., van Heuven, S., Soetaert, K., Laane, R. W. P. M., and Middelburg, J. J.: Seasonal and long-term changes in pH in the Dutch coastal zone, Biogeosciences, 7, 3869–3878, https://doi.org/10.5194/bg-7-3869-2010, 2010.
Raaphorst, W., Kloosterhuis H. T., Cramer, A., and Bakker, K. J. M.:
Nutrient early diagenesis in the sandy sediments of the Dogger Bank area,
North Sea: pore water results, Neth. J. Sea Res., 26, 25–52, https://doi.org/10.1016/0077-7579(90)90054-K, 1990.
Radach, G. and Pätsch, J.: Variability of Continental Riverine
Freshwater and Nutrient Inputs into the North Sea for the Years 1977–2000
and Its Consequences for the Assessment of Eutrophication, Estuar.
Coast., 30, 66–81, https://doi.org/10.1007/BF02782968, 2007.
Rassmann, J., Eitel, E. M., Lansard, B., Cathalot, C., Brandily, C., Taillefert, M., and Rabouille, C.: Benthic alkalinity and dissolved inorganic carbon fluxes in the Rhône River prodelta generated by decoupled aerobic and anaerobic processes, Biogeosciences, 17, 13–33, https://doi.org/10.5194/bg-17-13-2020, 2020.
Reimer, S., Brasse, S., Doerffer, R., Dürselen, C. D., Kempe, S.,
Michaelis, W., and Seifert, R.: Carbon cycling in the German Bight: An
estimate of transformation processes and transport, Deutsche Hydr.
Zeitschr., 51, 313–329, https://doi.org/10.1007/BF02764179, 1999.
Riedel, T., Lettmann, K., Beck, M., and Brumsack, H.-J.: Tidal variations
in groundwater storage and associated discharge from an intertidal coastal
aquifer, J. Geophys. Res., 115, 1–10, 2010.
Rullkötter, J.: The back-barrier tidal flats in the southern North
Sea – a multidisciplinary approach to reveal the main driving forces shaping
the system, Ocean Dynam., 59, 157–165, https://doi.org/10.1007/s10236-009-0197-2,
2009.
Salt, L. A., Thomas, H., Prowe, A. E. F., Borges, A. V., Bozec, Y., and de
Baar, H. J. W.: Variability of North Sea pH and CO2 in response to
North Atlantic Oscillation forcing, J. Geophys. Res.-Biogeo., 118, 1584–1592, https://doi.org/10.1002/2013JG002306, 2013.
Santos, I. R., Eyre, B. D., and Huettel, M.: The driving forces
of porewater and groundwater flow in permeable coastal sediments: A review,
Estuar. Coast. Shelf S., 98, 1–15,
https://doi.org/10.1016/j.ecss.2011.10.024, 2012.
Santos, I. R., Beck, M., Brumsack, H.-J., Maher, D. T., Dittmar, T., Waska,
H., and Schnetger, B.: Porewater exchange as a driver of carbon dynamics
across a terrestrial-marine transect: Insights from coupled 222Rn and
pCO2 observations in the German Wadden Sea, Mar. Chem., 171,
10–20, https://doi.org/10.1016/j.marchem.2015.02.005, 2015.
Schott, F.: Der Oberflächensalzgehalt in der Nordsee, Deutsche Hydr.
Zeitschr., Reije A Nr. 9, 1–29, 1966.
Schwichtenberg, F.: Drivers of the carbonate system variability in the
southern North Sea: River input, anaerobic alkalinity generation in the
Wadden Sea and internal processes, Doktorarbeit/PhS, Universität
Hamburg, Hamburg, Germany, 161 pp., 2013.
Seibert, S. L., Greskowiak, J., Prommer, H., Böttcher, M. E., Waska, H., and
Massmann, G.: Modeling biogeochemical processes in a barrier island
freshwater lens (Spiekeroog, Germany), J. Hydrol., 575, 1133–1144, 2019.
Seitzinger, S. and Giblin, A. E.: Estimating denitrification in North
Atlantic continental shelf sediments, Biogeochemistry, 35, 235–260, https://doi.org/10.1007/BF02179829, 1996.
Shadwick, E. H., Thomas, H., Azetsu-Scott, K., Greenan, B. J. W., Head, E.,
and Horne, E.: Seasonal variability of dissolved inorganic carbon and
surface water pCO2 in the Scotian Shelf region of the Northwestern
Atlantic, Mar. Chem., 124, 23–37,
https://doi.org/10.1016/j.marchem.2010.11.004, 2011.
Sippo, J. Z., Maher, D. T., Tait, D. R., Holloway, C., and Santos, I. R.: Are
mangroves drivers or buffers of coastal acidification? Insights from
alkalinity and dissolved inorganic carbon export estimates across a
latitudinal transect, Global Biogeochem. Cy., 30, 753–766, 2016.
Smith, S. V. and Hollibaugh, J. T.: Coastal metabolism and the oceanic
organic carbon balance, Rev. Geophys., 31, 75–89,
https://doi.org/10.1029/92RG02584, 1993.
Streif, H.: Das ostfriesische Wattenmeer. Nordsee, Inseln, Watten und
Marschen, Gebrüder Borntraeger, Berlin, 1990.
Su, J. and Pohlmann, T.: Wind and topography influence on an upwelling
system at the eastern Hainan coast, J. Geophys. Res.-Ocean.,
114, C06017, https://doi.org/10.1029/2008jc005018, 2009.
Sulzbacher, H., Wiederhold, H., Siemon, B., Grinat, M., Igel, J., Burschil, T., Günther, T., and Hinsby, K.: Numerical modelling of climate change impacts on freshwater lenses on the North Sea Island of Borkum using hydrological and geophysical methods, Hydrol. Earth Syst. Sci., 16, 3621–3643, https://doi.org/10.5194/hess-16-3621-2012, 2012.
Thomas, H.: Hydrochemistry measured on water bottle samples during PELAGIA cruise 64PE184. Department of Oceanography, Dalhousie University, Halifax, PANGAEA, https://doi.org/10.1594/PANGAEA.438791, 2006.
Thomas, H. and Borges, A. V.: Hydrochemistry measured on water bottle samples during PELAGIA cruise 64PE239, PANGAEA, https://doi.org/10.1594/PANGAEA.441686, 2006.
Thomas, H., Bozec, Y., Elkalay, K., and de Baar, H. J. W.: Enhanced open
ocean storage of CO2 from shelf sea pumping, Science, 304, 1005–1008,
https://doi.org/10.1126/science.1095491, 2004.
Thomas, H., Schiettecatte, L.-S., Suykens, K., Kone, Y. J. M., Shadwick, E.
H., Prowe, A. E. F., Bozec, Y., De Baar, H. J. W., and Borges, A. V.:
Enhanced ocean carbon storage from anaerobic alkalinity generation in
coastal sediments, Biogeosciences, 6, 267–274, https://doi.org/10.5194/bg-6-267-2009,
2009.
Uni Hamburg: ECOHAMDATA_RIVER, available at: https://wiki.cen.uni-hamburg.de/ifm/ECOHAM/DATA_RIVER, last access: 20 August 2020.
van Beusekom, J. E. E., Loebl, M., and Martens, P.: Distant riverine
nutrient supply and local temperature drive the long-term phytoplankton
development in a temperate coastal basin, J. Sea Res., 61, 26–33,
https://doi.org/10.1016/j.seares.2008.06.005, 2009.
van Beusekom, J. E. E., Buschbaum, C., and Reise, K.: Wadden Sea tidal
basins and the mediating role of the North Sea in ecological processes:
scaling up of management?, Ocean Coast. Manage., 68, 69–78,
https://doi.org/10.1016/j.ocecoaman.2012.05.002, 2012.
van Beusekom, J. E. E., Carstensen, J., Dolch, T., Grage, A., Hofmeister,
R., Lenhart , H.-J., Kerimoglu, O., Kolbe, K., Pätsch, J., Rick, J.,
Rönn, L., and Ruiter, H.: Wadden Sea Eutrophication: Long-Term Trends
and Regional Differences, Front. Mar. Sci., 6, https://doi.org/10.3389/fmars.2019.00370, 2019.
van Goor, M. A., Zitman, T. J., Wang, Z. B., and Stive, M. J. F.: Impact of
sea-level rise on the equilibrium state of tidal inlets, Mar. Geol., 202,
211–227, https://doi.org/10.1016/S0025-3227(03)00262-7, 2003.
van Koningsveld, M., Mulder, J. P. M., Stive, M. J. F., Van der Valk, L.,
and Van der Weck, A. W.: Living with sea-level rise and climate change: a
case study of the Netherlands, J. Coast. Res., 24, 367–379,
https://doi.org/10.2112/07A-0010.1, 2008.
Wang, Z. A. and Cai, W.-J.: Carbon dioxide degassing and inorganic carbon
export from a marsh-dominated estuary (the Duplin River): A marsh CO2
pump, Limnol. Oceanogr., 49, 341–354,
https://doi.org/10.4319/lo.2004.49.2.0341, 2004.
Winde, V.: Zum Einfluss von benthischen und pelagischen Prozessen auf das
Karbonatsystem des Wattenmeeres der Nordsee, Dr.rer.nat. thesis, EMA
University of Greifswald, 2013.
Winde, V., Böttcher, M. E., Escher, P., Böning, P., Beck, M.,
Liebezeit, G., and Schneider, B.: Tidal and spatial variations of DI13C
and aquatic chemistry in a temperate tidal basin during winter time, J.
Marine Syst., 129, 396–404, https://doi.org/10.1016/j.jmarsys.2013.08.005, 2014.
Winde, V., Böttcher, M. E., Escher, P., Böning, P., Beck, M., and Schneider, B.: Tidal and spatial variations of DI13C and aquatic chemistry in a temperate tidal basin during winter time, PANGAEA, https://doi.org/10.1594/PANGAEA.841976, 2015.
Wolf-Gladrow, D. A., Zeebe, R. E., Klaas, C., Kortzinger, A., and Dickson,
A. G.: Total alkalinity: The explicit conservative expression and its
application to biogeochemical processes, Mar. Chem., 106, 287–300,
https://doi.org/10.1016/j.marchem.2007.01.006, 2007.
Wurgaft, E., Findlay, A. J., Vigderovich, H., Herut, B., and Sivan, O.: Sulfate
reduction rates in the sediments of the Mediterranean continental shelf
inferred from combined dissolved inorganic carbon and total alkalinity
profiles, Mar. Chem., 211, 64–74, 2019.
Zeebe, R. E. and Wolf-Gladrow, D.: CO2 in seawater: Equilibrium,
Kinetics, Isotopes, Elsevier Science Ltd., Amsterdam, London, New York, Oxford, Paris, Shannon, Tokyo,
2001.
Zhai, W.-D., Yan, X.-L., and Qi, D.: Biogeochemical generation of dissolved
inorganic carbon and nitrogen in the North Branch of inner Changjiang
Estuary in a dry season, Estuar. Coast. Shelf S., 197, 136–149,
2017.
Short summary
Ocean acidification has a range of potentially harmful consequences for marine organisms. It is related to total alkalinity (TA) mainly produced in oxygen-poor situations like sediments in tidal flats. TA reduces the sensitivity of a water body to acidification. The decomposition of organic material and subsequent TA release in the tidal areas of the North Sea (Wadden Sea) is responsible for reduced acidification in the southern North Sea. This is shown with the results of an ecosystem model.
Ocean acidification has a range of potentially harmful consequences for marine organisms. It is...
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