Articles | Volume 12, issue 5
https://doi.org/10.5194/bg-12-1561-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/bg-12-1561-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
11 Mar 2015
Research article |
| 11 Mar 2015
Biogeochemical processes and buffering capacity concurrently affect acidification in a seasonally hypoxic coastal marine basin
Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, the Netherlands
C. P. Slomp
Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, the Netherlands
F. J. R. Meysman
Department of Ecosystem Studies, Royal Netherlands Institute for Sea Research, Yerseke, the Netherlands
Department of Analytical, Environmental and Geochemistry, Faculty of Science, Vrije Universiteit Brussel, Brussels, Belgium
D. Seitaj
Department of Ecosystem Studies, Royal Netherlands Institute for Sea Research, Yerseke, the Netherlands
J. Harlay
Chemical Oceanography Unit, University of Liège, Liège, Belgium
present address: Department of Oceanography, University of Hawaii, Honolulu, Hawaii, USA
A. V. Borges
Chemical Oceanography Unit, University of Liège, Liège, Belgium
J. J. Middelburg
Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, the Netherlands
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Olivier Sulpis, Siv K. Lauvset, and Mathilde Hagens
Ocean Sci., 16, 847–862, https://doi.org/10.5194/os-16-847-2020, https://doi.org/10.5194/os-16-847-2020, 2020
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Jingjing Guo, Miriam Glendell, Jeroen Meersmans, Frédérique Kirkels, Jack J. Middelburg, and Francien Peterse
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Julien Richirt, Bettina Riedel, Aurélia Mouret, Magali Schweizer, Dewi Langlet, Dorina Seitaj, Filip J. R. Meysman, Caroline P. Slomp, and Frans J. Jorissen
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This knowledge is especially useful to better understand the ecology of benthic foraminifera but also in the context of palaeoceanographic interpretations.
Alberto V. Borges, François Darchambeau, Thibault Lambert, Cédric Morana, George H. Allen, Ernest Tambwe, Alfred Toengaho Sembaito, Taylor Mambo, José Nlandu Wabakhangazi, Jean-Pierre Descy, Cristian R. Teodoru, and Steven Bouillon
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Multicellular cable bacteria form long filaments that can reach lengths of several centimeters. They affect the chemistry and mineralogy of their surroundings and vice versa. How the surroundings affect the cable bacteria is investigated. They show three different types of biomineral formation: (1) a polymer containing phosphorus in their cells, (2) a sheath of clay surrounding the surface of the filament and (3) the encrustation of a filament via a solid phase containing iron and phosphorus.
Gwenaël Abril and Alberto V. Borges
Biogeosciences, 16, 769–784, https://doi.org/10.5194/bg-16-769-2019, https://doi.org/10.5194/bg-16-769-2019, 2019
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Based on classical concepts in ecology, and a literature survey, we highlight the importance of flooded land as a preferential source of atmospheric carbon to aquatic systems at the global scale. Studies in terrestrial and aquatic ecosystems could be reconciled by considering the occurrence of an efficient wetland CO2 pump to river systems. New methodological approaches coupling hydrology and ecology are also necessary to improve scientific knowledge on carbon fluxes at the land–water interface.
Erik Gustafsson, Mathilde Hagens, Xiaole Sun, Daniel C. Reed, Christoph Humborg, Caroline P. Slomp, and Bo G. Gustafsson
Biogeosciences, 16, 437–456, https://doi.org/10.5194/bg-16-437-2019, https://doi.org/10.5194/bg-16-437-2019, 2019
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This work highlights that iron (Fe) dynamics plays a key role in the release of alkalinity from sediments, as exemplified for the Baltic Sea. It furthermore demonstrates that burial of Fe sulfides should be included in alkalinity budgets of low-oxygen basins. The sedimentary alkalinity generation may undergo large changes depending on both organic matter loads and oxygen conditions. Enhanced release of alkalinity from the seafloor can increase the CO2 storage capacity of seawater.
Ilja J. Kocken, Marlow Julius Cramwinckel, Richard E. Zeebe, Jack J. Middelburg, and Appy Sluijs
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Marine organic carbon burial could link the 405 thousand year eccentricity cycle in the long-term carbon cycle to that observed in climate records. Here, we simulate the response of the carbon cycle to astronomical forcing. We find a strong 2.4 million year cycle in the model output, which is present as an amplitude modulator of the 405 and 100 thousand year eccentricity cycles in a newly assembled composite record.
Wytze K. Lenstra, Matthias Egger, Niels A. G. M. van Helmond, Emma Kritzberg, Daniel J. Conley, and Caroline P. Slomp
Biogeosciences, 15, 6979–6996, https://doi.org/10.5194/bg-15-6979-2018, https://doi.org/10.5194/bg-15-6979-2018, 2018
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We show that burial rates of phosphorus (P) in an estuary in the northern Baltic Sea are very high. We demonstrate that at high sedimentation rates, P retention in the sediment is related to the formation of vivianite. With a reactive transport model, we assess the sensitivity of sedimentary vivianite formation. We suggest that enrichments of iron and P in the sediment are linked to periods of enhanced riverine input of Fe, which subsequently strongly enhances P burial in coastal sediments.
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
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A 2-year biogeochemical record provides annual sediment and element flux estimates for the non-dammed Sabaki River, Kenya, establishing a baseline for future research in light of impending construction of the first major upstream reservoir. Over 80 % of material fluxes occur across the wet season, with annual yields comparable to the adjacent, and dammed, Tana River. Observations at low-flow periods suggest large mammalian herbivores may be vectors of terrestrial subsidies to the water column.
Alberto V. Borges, Gwenaël Abril, and Steven Bouillon
Biogeosciences, 15, 1093–1114, https://doi.org/10.5194/bg-15-1093-2018, https://doi.org/10.5194/bg-15-1093-2018, 2018
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The Mekong River is among the largest on Earth and is vital for the economy of Vietnam and South East Asia and the livelihood of the local population (70 million across six countries). Numerous dams for hydropower are planned, which will affect the delivery of water and sediments to the Mekong delta, with numerous possible consequences. We report the dynamics of two greenhouse gases (CO2 and CH4) in the Mekong delta that can be used as a reference state to evaluate future changes.
Nikki Dijkstra, Mathilde Hagens, Matthias Egger, and Caroline P. Slomp
Biogeosciences, 15, 861–883, https://doi.org/10.5194/bg-15-861-2018, https://doi.org/10.5194/bg-15-861-2018, 2018
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We show that post-depositional formation of iron(II) phosphate as vivianite strongly alters the phosphorus record in sediments of the Bornholm Basin (Baltic Sea). These minerals began to precipitate in the lake sediments just after the last lake–marine transition ~ 7.5 kyr BP, migrated downwards and are now a stable feature. Formation of vivianite may affect sedimentary phosphorus records in other systems as well. This should be considered when using such records to reconstruct past environments.
Jack J. Middelburg
Biogeosciences, 15, 413–427, https://doi.org/10.5194/bg-15-413-2018, https://doi.org/10.5194/bg-15-413-2018, 2018
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Organic carbon processing at the seafloor is studied by geologists to better understand the sedimentary record, by biogeochemists to quantify burial and respiration, by organic geochemists to elucidate compositional changes, and by ecologists to follow carbon transfers within food webs. These disciplinary approaches have their strengths and weaknesses. This award talk provides a synthesis, highlights the role of animals in sediment carbon processing and presents some new concepts.
Jassin Petersen, Christine Barras, Antoine Bézos, Carole La, Lennart J. de Nooijer, Filip J. R. Meysman, Aurélia Mouret, Caroline P. Slomp, and Frans J. Jorissen
Biogeosciences, 15, 331–348, https://doi.org/10.5194/bg-15-331-2018, https://doi.org/10.5194/bg-15-331-2018, 2018
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In Lake Grevelingen, a coastal ecosystem, foraminifera experience important temporal variations in oxygen concentration and in pore water manganese. The high resolution of LA-ICP-MS allows us to analyse the chambers of foraminiferal shells separately and to obtain signals from a series of calcification events. We estimate the variability in Mn/Ca observed within single shells due to biomineralization and show that a substantial part of the signal is related to environmental variability.
Joost Frieling, Gert-Jan Reichart, Jack J. Middelburg, Ursula Röhl, Thomas Westerhold, Steven M. Bohaty, and Appy Sluijs
Clim. Past, 14, 39–55, https://doi.org/10.5194/cp-14-39-2018, https://doi.org/10.5194/cp-14-39-2018, 2018
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Past periods of rapid global warming such as the Paleocene–Eocene Thermal Maximum are used to study biotic response to climate change. We show that very high peak PETM temperatures in the tropical Atlantic (~ 37 ºC) caused heat stress in several marine plankton groups. However, only slightly cooler temperatures afterwards allowed highly diverse plankton communities to bloom. This shows that tropical plankton communities may be susceptible to extreme warming, but may also recover rapidly.
Ulrich Kotthoff, Jeroen Groeneveld, Jeanine L. Ash, Anne-Sophie Fanget, Nadine Quintana Krupinski, Odile Peyron, Anna Stepanova, Jonathan Warnock, Niels A. G. M. Van Helmond, Benjamin H. Passey, Ole Rønø Clausen, Ole Bennike, Elinor Andrén, Wojciech Granoszewski, Thomas Andrén, Helena L. Filipsson, Marit-Solveig Seidenkrantz, Caroline P. Slomp, and Thorsten Bauersachs
Biogeosciences, 14, 5607–5632, https://doi.org/10.5194/bg-14-5607-2017, https://doi.org/10.5194/bg-14-5607-2017, 2017
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We present reconstructions of paleotemperature, paleosalinity, and paleoecology from the Little Belt (Site M0059) over the past ~ 8000 years and evaluate the applicability of numerous proxies. Conditions were lacustrine until ~ 7400 cal yr BP. A transition to brackish–marine conditions then occurred within ~ 200 years. Salinity proxies rarely allowed quantitative estimates but revealed congruent results, while quantitative temperature reconstructions differed depending on the proxies used.
Laurine D. W. Burdorf, Anton Tramper, Dorina Seitaj, Lorenz Meire, Silvia Hidalgo-Martinez, Eva-Maria Zetsche, Henricus T. S. Boschker, and Filip J. R. Meysman
Biogeosciences, 14, 683–701, https://doi.org/10.5194/bg-14-683-2017, https://doi.org/10.5194/bg-14-683-2017, 2017
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Recently, long filamentous bacteria have been reported to conduct electrons over centimetre distances in marine sediments. These so-called cable bacteria have an
electricity-based metabolism, effectively turning the seafloor into a natural battery. In this study we demonstrate a global occurrence of these cable bacteria in marine sediments, spanning a large range of climate zones (off Greenland, the USA, Australia, the Netherlands) and a large range of coastal habitats.
Naomi Geeraert, Fred O. Omengo, Fredrick Tamooh, Trent R. Marwick, Alberto V. Borges, Gerard Govers, and Steven Bouillon
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-31, https://doi.org/10.5194/bg-2017-31, 2017
Manuscript not accepted for further review
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We observed that the relationship between the concentrations and the water discharge in the Tana River changed in wet seasons with and without flooding. Detailed sampling in those seasons is required in order to construct several rating curves and to obtain reliable flux estimates. The sediment and carbon fluxes in function of discharge will help us to asses the flux changes that can be expected when the hydrology changes due to climate change or human impact.
Dick van Oevelen, Christina E. Mueller, Tomas Lundälv, and Jack J. Middelburg
Biogeosciences, 13, 5789–5798, https://doi.org/10.5194/bg-13-5789-2016, https://doi.org/10.5194/bg-13-5789-2016, 2016
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Cold-water corals form true hotspots of biodiversity in the cold and dark deep sea, but need to live off of only small amounts of food that reach the deep sea. Using chemical tracers, this study investigated whether cold-water corals are picky eaters. We found that under low food conditions, they do not differentiate between food sources but they do differentiate at high food concentrations. This adaptation suggests that they are well adapted to exploit short food pulses efficiently.
Thibault Lambert, Steven Bouillon, François Darchambeau, Philippe Massicotte, and Alberto V. Borges
Biogeosciences, 13, 5405–5420, https://doi.org/10.5194/bg-13-5405-2016, https://doi.org/10.5194/bg-13-5405-2016, 2016
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This paper aims to investigate the spatial variability in dissolved organic matter (DOM) in terms of both concentration and composition in the Congo River network. Stable carbon isotopes and absorption and fluorescent properties of DOM were used as proxies for DOM composition. This study shows that DOM degradation within the Congo Basin results in the transition from aromatic to aliphatic DOM as well as the role of landscape and water residence time on this transition.
Matthias Egger, Peter Kraal, Tom Jilbert, Fatimah Sulu-Gambari, Célia J. Sapart, Thomas Röckmann, and Caroline P. Slomp
Biogeosciences, 13, 5333–5355, https://doi.org/10.5194/bg-13-5333-2016, https://doi.org/10.5194/bg-13-5333-2016, 2016
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By combining detailed geochemical analyses with diagenetic modeling, we provide new insights into how methane dynamics may strongly overprint burial records of iron, sulfur and phosphorus in marine systems subject to changes in organic matter loading or water column salinity. A better understanding of these processes will improve our ability to read ancient sediment records and thus to predict the potential consequences of global warming and human-enhanced inputs of nutrients to the ocean.
Dorothee C. E. Bakker, Benjamin Pfeil, Camilla S. Landa, Nicolas Metzl, Kevin M. O'Brien, Are Olsen, Karl Smith, Cathy Cosca, Sumiko Harasawa, Stephen D. Jones, Shin-ichiro Nakaoka, Yukihiro Nojiri, Ute Schuster, Tobias Steinhoff, Colm Sweeney, Taro Takahashi, Bronte Tilbrook, Chisato Wada, Rik Wanninkhof, Simone R. Alin, Carlos F. Balestrini, Leticia Barbero, Nicholas R. Bates, Alejandro A. Bianchi, Frédéric Bonou, Jacqueline Boutin, Yann Bozec, Eugene F. Burger, Wei-Jun Cai, Robert D. Castle, Liqi Chen, Melissa Chierici, Kim Currie, Wiley Evans, Charles Featherstone, Richard A. Feely, Agneta Fransson, Catherine Goyet, Naomi Greenwood, Luke Gregor, Steven Hankin, Nick J. Hardman-Mountford, Jérôme Harlay, Judith Hauck, Mario Hoppema, Matthew P. Humphreys, Christopher W. Hunt, Betty Huss, J. Severino P. Ibánhez, Truls Johannessen, Ralph Keeling, Vassilis Kitidis, Arne Körtzinger, Alex Kozyr, Evangelia Krasakopoulou, Akira Kuwata, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Claire Lo Monaco, Ansley Manke, Jeremy T. Mathis, Liliane Merlivat, Frank J. Millero, Pedro M. S. Monteiro, David R. Munro, Akihiko Murata, Timothy Newberger, Abdirahman M. Omar, Tsuneo Ono, Kristina Paterson, David Pearce, Denis Pierrot, Lisa L. Robbins, Shu Saito, Joe Salisbury, Reiner Schlitzer, Bernd Schneider, Roland Schweitzer, Rainer Sieger, Ingunn Skjelvan, Kevin F. Sullivan, Stewart C. Sutherland, Adrienne J. Sutton, Kazuaki Tadokoro, Maciej Telszewski, Matthias Tuma, Steven M. A. C. van Heuven, Doug Vandemark, Brian Ward, Andrew J. Watson, and Suqing Xu
Earth Syst. Sci. Data, 8, 383–413, https://doi.org/10.5194/essd-8-383-2016, https://doi.org/10.5194/essd-8-383-2016, 2016
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Version 3 of the Surface Ocean CO2 Atlas (www.socat.info) has 14.5 million CO2 (carbon dioxide) values for the years 1957 to 2014 covering the global oceans and coastal seas. Version 3 is an update to version 2 with a longer record and 44 % more CO2 values. The CO2 measurements have been made on ships, fixed moorings and drifting buoys. SOCAT enables quantification of the ocean carbon sink and ocean acidification, as well as model evaluation, thus informing climate negotiations.
Clare Woulds, Steven Bouillon, Gregory L. Cowie, Emily Drake, Jack J. Middelburg, and Ursula Witte
Biogeosciences, 13, 4343–4357, https://doi.org/10.5194/bg-13-4343-2016, https://doi.org/10.5194/bg-13-4343-2016, 2016
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Estuarine sediments are important locations for carbon cycling and burial. We used tracer experiments to investigate how site conditions affect the way in which seafloor biological communities cycle carbon. We showed that while total respiration rates are primarily determined by temperature, total carbon processing by the biological community is strongly related to
its biomass. Further, we saw a distinct pattern of carbon cycling in sandy sediment, in which uptake by bacteria dominates.
Fleur A. E. Roland, François Darchambeau, Cédric Morana, Sean A. Crowe, Bo Thamdrup, and Alberto V. Borges
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-300, https://doi.org/10.5194/bg-2016-300, 2016
Manuscript not accepted for further review
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We studied methane consumption in a tropical Great Lake (Lake Kivu, East Africa). Lake Kivu has huge methane concentrations in its deep anoxic waters, but is a very poor emitter of methane to the atmosphere, which suppose a strong methane consumption in the water column. During this study, we put in evidence high aerobic and anaerobic consumption rates, whose relative importance varied with the season (higher aerobic rates in dry season, when the oxic compartment is wider).
Thibault Lambert, Cristian R. Teodoru, Frank C. Nyoni, Steven Bouillon, François Darchambeau, Philippe Massicotte, and Alberto V. Borges
Biogeosciences, 13, 2727–2741, https://doi.org/10.5194/bg-13-2727-2016, https://doi.org/10.5194/bg-13-2727-2016, 2016
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This manuscript presents a detailed analysis of transport and transformation of dissolved organic matter along the Zambezi River and its largest tributary. A particular focus is put on the effects of floodplains/wetlands and reservoirs as well as low-flow vs. high-flow conditions on the longitudinal patterns in DOM concentration and composition. It is the first study to present such a detailed analysis for a whole, large river system, and in particular for a tropical river other than the Amazon.
Arthur H. W. Beusen, Alexander F. Bouwman, Ludovicus P. H. Van Beek, José M. Mogollón, and Jack J. Middelburg
Biogeosciences, 13, 2441–2451, https://doi.org/10.5194/bg-13-2441-2016, https://doi.org/10.5194/bg-13-2441-2016, 2016
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Intensifying anthropogenic activity over the 20th century including agriculture, water consumption, urbanization, and aquaculture has almost doubled the global nitrogen (N) and phosphorus (P) delivery to streams and steadily increased the N : P ratio in freshwater bodies. Concurrently, the cumulative number of reservoirs has driven a rise in freshwater nutrient retention and removal. Still, river nutrient transport to the ocean has also nearly doubled, potentially stressing coastal environments.
H. Brenner, U. Braeckman, M. Le Guitton, and F. J. R. Meysman
Biogeosciences, 13, 841–863, https://doi.org/10.5194/bg-13-841-2016, https://doi.org/10.5194/bg-13-841-2016, 2016
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Alkalinity released from sediments of the southern North Sea can play an important role in the carbon cycle of the North Sea by lowering the pCO2 of the seawater and thus increasing the CO2 flux between the atmosphere and the water. However, not every single mole alkalinity generated in sediments leads to an additional CO2 uptake, as certain reactions in the water column can negate the respective alkalinity release.
A. H. W. Beusen, L. P. H. Van Beek, A. F. Bouwman, J. M. Mogollón, and J. J. Middelburg
Geosci. Model Dev., 8, 4045–4067, https://doi.org/10.5194/gmd-8-4045-2015, https://doi.org/10.5194/gmd-8-4045-2015, 2015
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The IMAGE-Global Nutrient Model (GNM) is used to study the impact of multiple environmental changes on N and P delivery to surface water and transport and in-stream retention in rivers, lakes, wetlands and reservoirs over prolonged time periods. N and P are delivered to water bodies via diffuse sources (agriculture and natural ecosystems) and wastewater. N and P retention in a water body is calculated on the basis of the residence time of the water and nutrient uptake velocity.
C. Lenz, T. Jilbert, D.J. Conley, M. Wolthers, and C.P. Slomp
Biogeosciences, 12, 4875–4894, https://doi.org/10.5194/bg-12-4875-2015, https://doi.org/10.5194/bg-12-4875-2015, 2015
C. Morana, F. Darchambeau, F. A. E. Roland, A. V. Borges, F. Muvundja, Z. Kelemen, P. Masilya, J.-P. Descy, and S. Bouillon
Biogeosciences, 12, 4953–4963, https://doi.org/10.5194/bg-12-4953-2015, https://doi.org/10.5194/bg-12-4953-2015, 2015
C. R. Teodoru, F. C. Nyoni, A. V. Borges, F. Darchambeau, I. Nyambe, and S. Bouillon
Biogeosciences, 12, 2431–2453, https://doi.org/10.5194/bg-12-2431-2015, https://doi.org/10.5194/bg-12-2431-2015, 2015
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CO2 and CH4 concentrations and fluxes in the Zambezi River basin are well below the median/average values reported previously for tropical rivers, streams and reservoirs, and mainly controlled by the connectivity with floodplains and the presence of waterfalls and man-made reservoirs. The mass balance suggests that carbon transport to the ocean represents the major component (~60%) of the budget, while emissions to the atmosphere account for less than 40% of the total carbon yield.
L. Meire, D. H. Søgaard, J. Mortensen, F. J. R. Meysman, K. Soetaert, K. E. Arendt, T. Juul-Pedersen, M. E. Blicher, and S. Rysgaard
Biogeosciences, 12, 2347–2363, https://doi.org/10.5194/bg-12-2347-2015, https://doi.org/10.5194/bg-12-2347-2015, 2015
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The Greenland Ice Sheet releases large amounts of freshwater, which strongly influences the biogeochemistry of the adjacent fjord systems and continental shelves. Here we present seasonal observations of the carbonate system in the surface waters of a west Greenland tidewater outlet glacier fjord. Our data reveal a permanent undersaturation of CO2 in the surface layer of the entire fjord and adjacent shelf, creating a high annual uptake of 65gCm-2yr-1.
C. Morana, A. V. Borges, F. A. E. Roland, F. Darchambeau, J.-P. Descy, and S. Bouillon
Biogeosciences, 12, 2077–2088, https://doi.org/10.5194/bg-12-2077-2015, https://doi.org/10.5194/bg-12-2077-2015, 2015
G. Abril, S. Bouillon, F. Darchambeau, C. R. Teodoru, T. R. Marwick, F. Tamooh, F. Ochieng Omengo, N. Geeraert, L. Deirmendjian, P. Polsenaere, and A. V. Borges
Biogeosciences, 12, 67–78, https://doi.org/10.5194/bg-12-67-2015, https://doi.org/10.5194/bg-12-67-2015, 2015
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We compared pCO2 data calculated from pH and alkalinity from those measured directly in a large array of temperate and tropical freshwaters. This revealed a large overestimation (up to 300%) of calculated pCO2 in the case of acidic and organic-rich waters, due to a contribution of organic acids anions to alkalinity and a lower buffering capacity of the carbonate system at acidic pH. Given the widespread distribution of acidic freshwaters, direct measurements of water pCO2 are encouraged.
A. de Kluijver, P. L. Schoon, J. A. Downing, S. Schouten, and J. J. Middelburg
Biogeosciences, 11, 6265–6276, https://doi.org/10.5194/bg-11-6265-2014, https://doi.org/10.5194/bg-11-6265-2014, 2014
A. Sluijs, L. van Roij, G. J. Harrington, S. Schouten, J. A. Sessa, L. J. LeVay, G.-J. Reichart, and C. P. Slomp
Clim. Past, 10, 1421–1439, https://doi.org/10.5194/cp-10-1421-2014, https://doi.org/10.5194/cp-10-1421-2014, 2014
P. Ciais, A. J. Dolman, A. Bombelli, R. Duren, A. Peregon, P. J. Rayner, C. Miller, N. Gobron, G. Kinderman, G. Marland, N. Gruber, F. Chevallier, R. J. Andres, G. Balsamo, L. Bopp, F.-M. Bréon, G. Broquet, R. Dargaville, T. J. Battin, A. Borges, H. Bovensmann, M. Buchwitz, J. Butler, J. G. Canadell, R. B. Cook, R. DeFries, R. Engelen, K. R. Gurney, C. Heinze, M. Heimann, A. Held, M. Henry, B. Law, S. Luyssaert, J. Miller, T. Moriyama, C. Moulin, R. B. Myneni, C. Nussli, M. Obersteiner, D. Ojima, Y. Pan, J.-D. Paris, S. L. Piao, B. Poulter, S. Plummer, S. Quegan, P. Raymond, M. Reichstein, L. Rivier, C. Sabine, D. Schimel, O. Tarasova, R. Valentini, R. Wang, G. van der Werf, D. Wickland, M. Williams, and C. Zehner
Biogeosciences, 11, 3547–3602, https://doi.org/10.5194/bg-11-3547-2014, https://doi.org/10.5194/bg-11-3547-2014, 2014
J. J. Middelburg
Biogeosciences, 11, 2357–2371, https://doi.org/10.5194/bg-11-2357-2014, https://doi.org/10.5194/bg-11-2357-2014, 2014
I. Ruvalcaba Baroni, R. P. M. Topper, N. A. G. M. van Helmond, H. Brinkhuis, and C. P. Slomp
Biogeosciences, 11, 977–993, https://doi.org/10.5194/bg-11-977-2014, https://doi.org/10.5194/bg-11-977-2014, 2014
T. R. Marwick, F. Tamooh, B. Ogwoka, C. Teodoru, A. V. Borges, F. Darchambeau, and S. Bouillon
Biogeosciences, 11, 443–460, https://doi.org/10.5194/bg-11-443-2014, https://doi.org/10.5194/bg-11-443-2014, 2014
C. E. Mueller, A. I. Larsson, B. Veuger, J. J. Middelburg, and D. van Oevelen
Biogeosciences, 11, 123–133, https://doi.org/10.5194/bg-11-123-2014, https://doi.org/10.5194/bg-11-123-2014, 2014
F. Tamooh, A. V. Borges, F. J. R. Meysman, K. Van Den Meersche, F. Dehairs, R. Merckx, and S. Bouillon
Biogeosciences, 10, 6911–6928, https://doi.org/10.5194/bg-10-6911-2013, https://doi.org/10.5194/bg-10-6911-2013, 2013
L. Pozzato, D. Van Oevelen, L. Moodley, K. Soetaert, and J. J. Middelburg
Biogeosciences, 10, 6879–6891, https://doi.org/10.5194/bg-10-6879-2013, https://doi.org/10.5194/bg-10-6879-2013, 2013
L. Meire, K. E. R. Soetaert, and F. J. R. Meysman
Biogeosciences, 10, 2633–2653, https://doi.org/10.5194/bg-10-2633-2013, https://doi.org/10.5194/bg-10-2633-2013, 2013
B. Veuger, A. Pitcher, S. Schouten, J. S. Sinninghe Damsté, and J. J. Middelburg
Biogeosciences, 10, 1775–1785, https://doi.org/10.5194/bg-10-1775-2013, https://doi.org/10.5194/bg-10-1775-2013, 2013
A. de Kluijver, K. Soetaert, J. Czerny, K. G. Schulz, T. Boxhammer, U. Riebesell, and J. J. Middelburg
Biogeosciences, 10, 1425–1440, https://doi.org/10.5194/bg-10-1425-2013, https://doi.org/10.5194/bg-10-1425-2013, 2013
K. A. Koho, K. G. J. Nierop, L. Moodley, J. J. Middelburg, L. Pozzato, K. Soetaert, J. van der Plicht, and G-J. Reichart
Biogeosciences, 10, 1131–1141, https://doi.org/10.5194/bg-10-1131-2013, https://doi.org/10.5194/bg-10-1131-2013, 2013
A. F. Bouwman, M. F. P. Bierkens, J. Griffioen, M. M. Hefting, J. J. Middelburg, H. Middelkoop, and C. P. Slomp
Biogeosciences, 10, 1–22, https://doi.org/10.5194/bg-10-1-2013, https://doi.org/10.5194/bg-10-1-2013, 2013
Related subject area
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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
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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
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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
Effects of Submarine Groundwater on Nutrient Concentration and Primary Production in a Deep Bay of the Japan Sea
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Spring-neap tidal cycles modulate the strength of the carbon source at the estuary-coast interface
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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
The bacteria-protist link as a main route of dissolved organic matter across contrasting productivity areas in the Patagonian Shelf
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
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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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.
Menghong Dong, Xinyu Guo, Takuya Matsuura, Taichi Tebakari, and Jing Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-2581, https://doi.org/10.5194/egusphere-2024-2581, 2024
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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.
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
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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
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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
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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
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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
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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
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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.
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
EGUsphere, https://doi.org/10.5194/egusphere-2024-1860, https://doi.org/10.5194/egusphere-2024-1860, 2024
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This study examines how microbial community structure, growth, and grazing impact the DOM pool in the Patagonian Shelf. Despite higher phytoplankton biomass, faster-growing bacteria were selectively grazed by protists leading to DOM accumulation, likely due to a reduction in DOM-consuming bacteria and the addition of egestion compounds. Experimental data showed that while bacteria remained as the primarily shapers of DOM quality, grazing pressure impacted on DOM accumulation.
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
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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 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
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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
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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
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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
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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
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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
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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.
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.
Cited articles
Bannink, B. A., Van der Meulen, J. H. M., and Nienhuis, P. H.: Lake Grevelingen: from an estuary to a saline lake. An introduction, Netherlands J. Sea Res., 18, 179–190, 1984.
Ben-Yaakov, S.: pH buffering of pore water of recent anoxic marine sediments, Limnol. Oceanogr., 18, 86–94, 1973.
Borges, A. V. and Gypens, N.: Carbonate chemistry in the coastal zone responds more strongly to eutrophication than ocean acidification, Limnol. Oceanogr., 55, 346–353, 2010.
Brewer, P. G. and Peltzer, E. T.: Limits to marine life, Science, 324, 347–348, 2009.
Burnett, L. E.: The challenges of living in hypoxic and hypercapnic aquatic environments, Integr. Comp. Biol., 37, 633–640, 1997.
Cadée, G. C. and Hegeman, J.: Historical phytoplankton data of the Marsdiep, Hydrobiol. Bull., 24, 111–118, 1991.
Cai, W.-J., Wang, Y., and Hodson, R. E.: Acid–base properties of dissolved organic matter in the estuarine waters of Georgia, USA, Geochim. Cosmochim. Acta, 62, 473–483, 1998.
Cai, W.-J., Hu, X., Huang, W.-J., Murrell, M. C., Lehrter, J. C., Lohrenz, S. E., Chou, W.-C., Zhai, W., Hollibaugh, J. T., Wang, Y., Zhao, P., Guo, X., Gundersen, K., Dai, M., and Gong, G.-C.: Acidification of subsurface coastal waters enhanced by eutrophication, Nat. Geosci., 4, 766–770, 2011.
Cantoni, C., Luchetta, A., Celio, M., Cozzi, S., Raicich, F., and Catalano, G.: Carbonate system variability in the Gulf of Trieste (North Adriatic Sea), Estuar. Coast. Shelf Sci., 115, 51–62, 2012.
Diaz, R. J. and Rosenberg, R.: Spreading dead zones and consequences for marine ecosystems, Science, 321, 926–929, 2008.
Dickson, A. G. and Millero, F. J.: A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media, Deep Sea Res. Pt. A, 34, 1733–1743, 1987.
Dickson, A. G., Sabine, C. L., and Christian, J. R. (Eds.): Guide to Best Practices for Ocean CO2 Measurements, PICES Special Publication 3, 2007.
Dickson, A. G.: The carbon dioxide system in seawater: equilibrium chemistry and measurements, in: Guide to Best Practices for Ocean Acidification Research and Data Reporting, edited by: Riebesell, U., Fabry, V. J., Hansson, L., and Gattuso, J.-P., Luxembourg, Publications Office of the European Union, 17–40, 2010.
Dortch, Q.: The interaction between ammonium and nitrate uptake in phytoplankton, Mar. Ecol. Prog. Ser., 61, 183–201, 1990.
Driscoll, C. T., Fuller, R. D., and Schecher, W. D.: The role of organic acids in the acidification of surface waters in the Eastern U.S, Water. Air. Soil Pollut., 43, 21–40, 1989.
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.
Edman, M. and Omstedt, A.: Modeling the dissolved CO2 system in the redox environment of the Baltic Sea, Limnol. Oceanogr., 58, 74–92, 2013.
Egleston, E. S., Sabine, C. L., and Morel, F. M. M.: Revelle revisited: Buffer factors that quantify the response of ocean chemistry to changes in DIC and alkalinity, Global Biogeochem. Cy., 24, GB1002, https://doi.org/10.1029/2008GB003407, 2010.
Eilers, P. H. C. and Peeters, J. C. H.: A model for the relationship between light intensity and the rate of photosynthesis in phytoplankton, Ecol. Modell., 42, 199–215, 1988.
Feely, R. A., Alin, S. R., Newton, J., Sabine, C. L., Warner, M., Devol, A., Krembs, C., and Maloy, C.: The combined effects of ocean acidification, mixing, and respiration on pH and carbonate saturation in an urbanized estuary, Estuar. Coast. Shelf Sci., 88, 442–449, 2010.
Feistel, R.: A Gibbs function for seawater thermodynamics for −6 to 80 °C and salinity up to 120gkg–1, Deep Sea Res. Pt. I, 55, 1639–1671, 2008.
Frankignoulle, M.: A complete set of buffer factors for acid/base CO2 system in seawater, J. Mar. Syst., 5, 111–118, 1994.
Frankignoulle, M. and Distèche, A.: CO2 chemistry in the water column above a Posidonia seagrass bed and related air-sea exchanges, Oceanol. Acta, 7, 209–219, 1984.
Gazeau, F., Borges, A., Barrón, C., Duarte, C., Iversen, N., Middelburg, J., Delille, B., Pizay, M., Frankignoulle, M., and Gattuso, J.: Net ecosystem metabolism in a micro-tidal estuary (Randers Fjord, Denmark): evaluation of methods, Mar. Ecol. Prog. Ser., 301, 23–41, 2005a.
Gazeau, F., Gattuso, J.-P., Middelburg, J. J., Brion, N., Schiettecatte, L.-S., Frankignoulle, M., and Borges, A. V.: Planktonic and whole system metabolism in a nutrient-rich estuary (the Scheldt estuary), Estuaries, 28, 868–883, 2005b.
Hagens, M., Hunter, K. A., Liss, P. S., and Middelburg, J. J.: Biogeochemical context impacts seawater pH changes resulting from atmospheric sulfur and nitrogen deposition, Geophys. Res. Lett., 41, 935–941, 2014.
Hernández-Ayon, J. M., Zirino, A., Dickson, A. G., Camiro-Vargas, T., and Valenzuela, E.: Estimating the contribution of organic bases from microalgae to the titration alkalinity in coastal seawaters, Limnol. Oceanogr. Methods, 5, 225–232, 2007.
Hofmann, A. F., Meysman, F. J. R., Soetaert, K., and Middelburg, J. J.: A step-by-step procedure for pH model construction in aquatic systems, Biogeosciences, 5, 227–251, https://doi.org/10.5194/bg-5-227-2008, 2008.
Hofmann, A. F., Middelburg, J. J., Soetaert, K., and Meysman, F. J. R.: pH modelling in aquatic systems with time-variable acid–base dissociation constants applied to the turbid, tidal Scheldt estuary, Biogeosciences, 6, 1539–1561, https://doi.org/10.5194/bg-6-1539-2009, 2009.
Hofmann, A. F., Middelburg, J. J., Soetaert, K., Wolf-Gladrow, D. A., and Meysman, F. J. R.: Proton cycling, buffering, and reaction stoichiometry in natural waters, Mar. Chem., 121, 246–255, 2010a.
Hofmann, A. F., Soetaert, K., Middelburg, J. J., and Meysman, F. J. R.: AquaEnv?: An aquatic acid–base modelling environment in R, Aquat. Geochem., 16, 507–546, 2010b.
Hofmann, G. E., Smith, J. E., Johnson, K. S., Send, U., Levin, L. A., Micheli, F., Paytan, A., Price, N. N., Peterson, B., Takeshita, Y., Matson, P. G., Crook, E. D., Kroeker, K. J., Gambi, M. C., Rivest, E. B., Frieder, C. A., Yu, P. C., and Martz, T. R.: High-frequency dynamics of ocean pH: a multi-ecosystem comparison, PLoS One, 6, e28983, https://doi.org/10.1371/journal.pone.0028983, 2011.
Hoppe, C. J. M., Langer, G., Rokitta, S. D., Wolf-Gladrow, D. A., and Rost, B.: Implications of observed inconsistencies in carbonate chemistry measurements for ocean acidification studies, Biogeosciences, 9, 2401–2405, https://doi.org/10.5194/bg-9-2401-2012, 2012.
Howarth, R., Chan, F., Conley, D. J., Garnier, J., Doney, S. C., Marino, R., and Billen, G.: Coupled biogeochemical cycles: eutrophication and hypoxia in temperate estuaries and coastal marine ecosystems, Front. Ecol. Environ., 9, 18–26, 2011.
Jury, C. P., Thomas, F. I. M., Atkinson, M. J., and Toonen, R. J.: Buffer capacity, ecosystem feedbacks, and seawater chemistry under global change, Water, 5, 1303–1325, 2013.
Kim, H.-C. and Lee, K.: Significant contribution of dissolved organic matter to seawater alkalinity, Geophys. Res. Lett., 36, L20603, https://doi.org/10.1029/2009GL040271, 2009.
Kim, H.-C., Lee, K., and Choi, W.: Contribution of phytoplankton and bacterial cells to the measured alkalinity of seawater, Limnol. Oceanogr., 51, 331–338, 2006.
Knap, A. H., Michaels, A. F., and Close, A.: The JGOFS Protocols, Intergovernmental Oceanographic Commission, 1994.
Koeve, W. and Oschlies, A.: Potential impact of DOM accumulation on fCO2 and carbonate ion computations in ocean acidification experiments, Biogeosciences, 9, 3787–3798, https://doi.org/10.5194/bg-9-3787-2012, 2012.
Lancelot, C., Gypens, N., Billen, G., Garnier, J., and Roubeix, V.: Testing an integrated river–ocean mathematical tool for linking marine eutrophication to land use: The Phaeocystis-dominated Belgian coastal zone (Southern North Sea) over the past 50 years, J. Mar. Syst., 64, 216–228, 2007.
Lee, D. Y., Owens, M. S., Doherty, M., Eggleston, E. M., Hewson, I., Crump, B. C., and Cornwell, J. C.: The effects of oxygen transition on community respiration and potential chemoautotrophic production in a seasonally stratified anoxic estuary, Estuar. Coast., 38, 104–117, 2015.
MacIsaac, J. J. and Dugdale, R. C.: Interactions of light and inorganic nitrogen in controlling nitrogen uptake in the sea, Deep Sea Res. Oceanogr. Abstr., 19, 209–232, 1972.
Malkin, S. Y., Rao, A. M., Seitaj, D., Vasquez-Cardenas, D., Zetsche, E.-M., Hidalgo-Martinez, S., Boschker, H. T., and Meysman, F. J.: Natural occurrence of microbial sulphur oxidation by long-range electron transport in the seafloor., ISME J., 8, 1843–1854, 2014.
Mehrbach, C., Culberson, C. H., Hawley, J. E., and Pytkowicz, R. M.: Measurement of the apparent dissociation constants of carbonic acid in seawater at atmospheric pressure, Limnol. Oceanogr., 18, 897–907, 1973.
Meijers, E. and Groot, S.: Deltamodel – hulpmiddel ter ondersteuning van het beheer en beleid van de zuidwestelijke Delta, Delft, Netherlands., 2007.
Melzner, F., Thomsen, J., Koeve, W., Oschlies, A., Gutowska, M. A., Bange, H. W., Hansen, H. P., and Körtzinger, A.: Future ocean acidification will be amplified by hypoxia in coastal habitats, Mar. Biol., 160, 1875–1888, 2013.
Middelburg, J. J. and Nieuwenhuize, J.: Nitrogen uptake by heterotrophic bacteria and phytoplankton in the nitrate-rich Thames estuary, Mar. Ecol. Prog. Ser., 203, 13–21, 2000.
Middelburg, J. J. and Herman, P. M. J.: Organic matter processing in tidal estuaries, Mar. Chem., 106, 127–147, 2007.
Morel, F. M. M. and Hering, J. G.: Principles and Applications of Aquatic Chemistry, First Edit., Wiley-Interscience, 1993.
Mucci, A., Starr, M., Gilbert, D., and Sundby, B.: Acidification of Lower St. Lawrence Estuary bottom waters, Atmos.-Oc., 49, 206–218, 2011.
Muller, F. L. L. and Bleie, B.: Estimating the organic acid contribution to coastal seawater alkalinity by potentiometric titrations in a closed cell, Anal. Chim. Acta, 619, 183–91, 2008.
Nienhuis, P. H.: An ecosystem study in Lake Grevelingen, a former estuary in the SW Netherlands, Kieler Meeresforschungen. Sonderh., 4, 247–255, 1978.
Nienhuis, P. H. and Huis in 't Veld, J. C.: Grevelingen: from an estuary to a saline lake, Water Sci. Technol., 16, 27–50, 1984.
Nixon, S. W.: Coastal marine eutrophication: a definition, social causes, and future concerns, Ophelia, 41, 199–219, 1995.
Nolte, A., Troost, T., de Boer, G., Spiteri, C., and van Wesenbeeck, B.: Verkenning oplossingsrichtingen voor een betere waterkwaliteit en ecologische toestand van het Grevelingenmeer, Delft, Netherlands, 2008.
Oliver, B. G., Thurman, E. M., and Malcolm, R. L.: The contribution of humic substances to the acidity of colored natural waters, Geochim. Cosmochim. Acta, 47, 2031–2035, 1983.
Omstedt, A., Gustafsson, E., and Wesslander, K.: Modelling the uptake and release of carbon dioxide in the Baltic Sea surface water, Cont. Shelf Res., 29, 870–885, 2009.
Orr, J. C., Fabry, V. J., Aumont, O., Bopp, L., Doney, S. C., Feely, R. A., Gnanadesikan, A., Gruber, N., Ishida, A., Joos, F., Key, R. M., Lindsay, K., Maier-Reimer, E., Matear, R., Monfray, P., Mouchet, A., Najjar, R. G., Plattner, G.-K., Rodgers, K. B., Sabine, C. L., Sarmiento, J. L., Schlitzer, R., Slater, R. D., Totterdell, I. J., Weirig, M.-F., Yamanaka, Y., and Yool, A.: Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms, Nature, 437, 681–686, 2005.
Peperzak, L. and Poelman, M.: Mass mussel mortality in The Netherlands after a bloom of Phaeocystis globosa (prymnesiophyceae), J. Sea Res., 60, 220–222, 2008.
Philippart, C. J. M., Beukema, J. J., Cadée, G. C., Dekker, R., Goedhart, P. W., van Iperen, J. M., Leopold, M. F., and Herman, P. M. J.: Impacts of nutrient reduction on coastal communities, Ecosystems, 10, 96–119, 2007.
Pierrot, D., Lewis, E., and Wallace, D. W. R.: MS Excel program developed for CO2 system calculations, Oak Ridge, Tennessee, USA, 2006.
Pieters, J. P. F., Bannink, B. A., and van de Kamer, J. P. G.: Een mathematisch model van de chlorideen zuurstofhuishouding van het Grevelingenmeer tijdens de uitwisseling met zeewater, Middelburg, Netherland, 1985.
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.
Redfield, A. C., Ketchum, B. H., and Richards, F. A.: The influence of organisms on the composition of sea-water, in: The Composition of Seawater. Comparative and Descriptive Oceanography, edited by: Hill, M. N., Interscience Publishers, New York, 26–77, 1963.
Regnier, P., Wollast, R., and Steefel, C. I.: Long-term fluxes of reactive species in macrotidal estuaries: Estimates from a fully transient, multicomponent reaction-transport model, Mar. Chem., 58, 127–145, 1997.
Revelle, R. and Suess, H. E.: Carbon dioxide exchange between atmosphere and ocean and the question of an increase of atmospheric CO2 during the past decades, Tellus, 9, 18–27, 1957.
Riley, G. A.: Plankton studies. II. The western north Atlantic, May-June 1939, J. Mar. Res., 2, 145–162, 1939.
Sayama, M., Risgaard-Petersen, N., Nielsen, L. P., Fossing, H., and Christensen, P. B.: Impact of bacterial NO3- transport on sediment biogeochemistry, Appl. Environ. Microbiol., 71, 7575–7577, 2005.
Schulz, K. G. and Riebesell, U.: Diurnal changes in seawater carbonate chemistry speciation at increasing atmospheric carbon dioxide, Mar. Biol., 160, 1889–1899, 2013.
Seitaj, D., Schauer, R., Sulu-Gambari, F., Malkin, S. Y., Hidalgo Martinez, S., Slomp, C. P., and Meysman, F. J. R.: Temporal succession of cryptic sulphur cycling in a seasonally hypoxic basin, in preparation, 2015a.
Seitaj, D., Sulu-Gambari, F., Malkin, S. Y., Burdorf, L., Slomp, C. P., and Meysman, F. J. R.: Sediment mineralization and benthic oxygen dynamics in a seasonally hypoxic basin, in preparation, 2015b.
Shadwick, E. H., Trull, T. W., Thomas, H., and Gibson, J. A. E.: Vulnerability of polar oceans to anthropogenic acidification: comparison of Arctic and Antarctic seasonal cycles., Sci. Rep., 3, 2339, https://doi.org/10.1038/srep02339, 2013.
Shaw, E. C., McNeil, B. I., Tilbrook, B., Matear, R., and Bates, M. L.: Anthropogenic changes to seawater buffer capacity combined with natural reef metabolism induce extreme future coral reef CO2 conditions, Glob. Chang. Biol., 19, 1632–1641, 2013.
Simpson, J. H.: The shelf-sea fronts: implications of their existence and behaviour, Philos. Trans. R. Soc. A Math. Phys. Eng. Sci., 302, 531–543, 1981.
Soetaert, K., Hofmann, A. F., Middelburg, J. J., Meysman, F. J. R., and Greenwood, J.: The effect of biogeochemical processes on pH, Mar. Chem., 105, 30–51, 2007.
Strickland, J. D. and Parsons, T. R.: A Practical Handbook of Seawater Analysis, 2nd Edition, Bulletin 167, Fisheries Research Board of Canada, Ottawa, Canada, 1972.
Stumm, W. and Morgan, J. J.: Aquatic Chemistry: Chemical Equilibria and Rates in Natural Waters, 3rd edition, John Wiley & Sons, Inc., 1996.
Sullivan, T., Byrne, C., Harman, L., Davenport, J., McAllen, R., and Regan, F.: Determination of spatial and temporal variability of pH and dissolved oxygen concentrations in a seasonally hypoxic semi-enclosed marine basin using continuous monitoring, Anal. Methods, 6, 5489–5497, 2014.
Sunda, W. G. and Cai, W.-J.: Eutrophication induced CO2-acidification of subsurface coastal waters: interactive effects of temperature, salinity, and atmospheric pCO2, Environ. Sci. Technol., 46, 10651–10659, 2012.
Sundquist, E. T., Plummer, L. N., and Wigley, T. M.: Carbon dioxide in the ocean surface: the homogeneous buffer factor, Science, 204, 1203–1205, 1979.
Taguchi, F. and Fujiwara, T.: Carbon dioxide stored and acidified low oxygen bottom waters in coastal seas, Japan, Estuar. Coast. Shelf Sci., 86, 429–433, 2010.
Thomas, H., Prowe, A. E. F., van Heuven, S., Bozec, Y., de Baar, H. J. W., Schiettecatte, L.-S., Suykens, K., Koné, M., Borges, A. V., Lima, I. D., and Doney, S. C.: Rapid decline of the CO2 buffering capacity in the North Sea and implications for the North Atlantic Ocean, Global Biogeochem. Cycles, 21, GB4001, https://doi.org/10.1029/2006GB002825, 2007.
Verschuur, G. L.: Transparency measurements in Garner Lake, Tennessee: the relationship between Secchi depth and solar altitude and a suggestion for normalization of Secchi depth data, Lake Reserv. Manag., 13, 142–153, 1997.
Wallace, R. B., Baumann, H., Grear, J. S., Aller, R. C., and Gobler, C. J.: Coastal ocean acidification: The other eutrophication problem, Estuar. Coast. Shelf Sci., 148, 1–13, 2014.
Wang, B., Chen, J., Jin, H., Li, H., and Xu, J.: Inorganic carbon parameters responding to summer hypoxia outside the Changjiang Estuary and the related implications, J. Ocean Univ. China, 12, 568–576, 2013.
Wanninkhof, R.: Relationship between wind speed and gas exchange over the ocean, J. Geophys. Res., 97, 7373–7382, https://doi.org/10.1029/92JC00188, 1992.
Weiss, R. F.: Carbon dioxide in water and seawater: the solubility of a non-ideal gas, Mar. Chem., 2, 203–215, 1974.
Weiss, R. F.: Determinations of carbon dioxide and methane by dual catalyst flame ionization chromatography and nitrous oxide by electron capture chromatography, J. Chromatogr. Sci., 19, 611–616, 1981.
Wetsteyn, L. P. M. J.: Grevelingenmeer: meer kwetsbaar?, Lelystad, Netherlands, 2011.
Wetsteyn, L. P. M. J. and Kromkamp, J. C.: Turbidity, nutrients and phytoplankton primary production in the Oosterschelde (The Netherlands) before, during and after a large-scale coastal engineering project (1980–1990), Hydrobiologia, 282/283, 61–78, 1994.
Wootton, J. T. and Pfister, C. A.: Carbon system measurements and potential climatic drivers at a site of rapidly declining ocean pH, PLoS One, 7, e53396, https://doi.org/10.1371/journal.pone.0053396, 2012.
Yates, K. K., Dufore, C., Smiley, N., Jackson, C., and Halley, R. B.: Diurnal variation of oxygen and carbonate system parameters in Tampa Bay and Florida Bay, Mar. Chem., 104, 110–124, 2007.
Zhai, W., Zhao, H., Zheng, N., and Xu, Y.: Coastal acidification in summer bottom oxygen-depleted waters in northwestern-northern Bohai Sea from June to August in 2011, Chinese Sci. Bull., 57, 1062–1068, 2012.
Zhang, J.-Z.: The use of pH and buffer intensity to quantify the carbon cycle in the ocean, Mar. Chem., 70, 121–131, 2000.
Short summary
This study looks at the combined impacts of hypoxia and acidification, two major environmental stressors affecting coastal systems, in a seasonally stratified basin. Here, the surface water experiences less seasonality in pH than the bottom water despite higher process rates. This is due to a substantial reduction in the acid-base buffering capacity of the bottom water as it turns hypoxic in summer. This highlights the crucial role of the buffering capacity as a modulating factor in pH dynamics.
This study looks at the combined impacts of hypoxia and acidification, two major environmental...
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