Articles | Volume 16, issue 4
https://doi.org/10.5194/bg-16-863-2019
© Author(s) 2019. 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-16-863-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
20 Feb 2019
Research article |
| 20 Feb 2019
| 20 Feb 2019
Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters
Filippa Fransner
CORRESPONDING AUTHOR
Department of Meteorology and Bolin Centre for Climate Research,
Stockholm University, Stockholm, Sweden
now at: Geophysical Institute, Bergen
University and Bjerknes Centre for Climate Research, Bergen, Norway
Agneta Fransson
Norwegian Polar Institute,
Fram Centre, Tromsø, Norway
Christoph Humborg
Baltic Nest Institute, Baltic Sea
Centre, Stockholm University, Stockholm, Sweden
Faculty of
Biological and Environmental Sciences, Tvärminne Zoological Station,
University of Helsinki, Hanko, Finland
Erik Gustafsson
Baltic Nest Institute, Baltic Sea
Centre, Stockholm University, Stockholm, Sweden
Letizia Tedesco
Marine Research Centre, Finnish Environment
Institute, Helsinki, Finland
Robinson Hordoir
Institute of Marine Research and Bjerknes Centre for Climate
Research, Bergen, Norway
Jonas Nycander
Department of Meteorology and Bolin Centre for Climate Research,
Stockholm University, Stockholm, Sweden
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Biogeosciences, 17, 2219–2244, https://doi.org/10.5194/bg-17-2219-2020, https://doi.org/10.5194/bg-17-2219-2020, 2020
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Murat Gunduz, Emin Özsoy, and Robinson Hordoir
Geosci. Model Dev., 13, 121–138, https://doi.org/10.5194/gmd-13-121-2020, https://doi.org/10.5194/gmd-13-121-2020, 2020
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The Bosphorus exchange is of critical importance for hydrodynamics and hydroclimatology of the Black Sea. In this study, we report on the development of a medium-resolution circulation model of the Black Sea, making use of surface atmospheric forcing with high space and time resolution, climatic river fluxes and strait exchange, enabled by adding elementary details of strait and coastal topography and seasonal hydrology specified in an artificial box on the Marmara Sea side.
Martin Jakobsson, Christian Stranne, Matt O'Regan, Sarah L. Greenwood, Bo Gustafsson, Christoph Humborg, and Elizabeth Weidner
Ocean Sci., 15, 905–924, https://doi.org/10.5194/os-15-905-2019, https://doi.org/10.5194/os-15-905-2019, 2019
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The bottom topography of the Baltic Sea is analysed using the digital depth model from the European Marine Observation and Data Network (EMODnet) published in 2018. Analyses include depth distribution vs. area and seafloor depth variation on a kilometre scale. The limits for the Baltic Sea and analysed sub-basins are from HELCOM. EMODnet is compared with the previously most widely used depth model and the area of deep water exchange between the Bothnian Sea and the Northern Baltic Proper.
Erik Gustafsson, Mathilde Hagens, Xiaole Sun, Daniel C. Reed, Christoph Humborg, Caroline P. Slomp, and Bo G. Gustafsson
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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.
Robinson Hordoir, Lars Axell, Anders Höglund, Christian Dieterich, Filippa Fransner, Matthias Gröger, Ye Liu, Per Pemberton, Semjon Schimanke, Helen Andersson, Patrik Ljungemyr, Petter Nygren, Saeed Falahat, Adam Nord, Anette Jönsson, Iréne Lake, Kristofer Döös, Magnus Hieronymus, Heiner Dietze, Ulrike Löptien, Ivan Kuznetsov, Antti Westerlund, Laura Tuomi, and Jari Haapala
Geosci. Model Dev., 12, 363–386, https://doi.org/10.5194/gmd-12-363-2019, https://doi.org/10.5194/gmd-12-363-2019, 2019
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Daiki Nomura, Mats A. Granskog, Agneta Fransson, Melissa Chierici, Anna Silyakova, Kay I. Ohshima, Lana Cohen, Bruno Delille, Stephen R. Hudson, and Gerhard S. Dieckmann
Biogeosciences, 15, 3331–3343, https://doi.org/10.5194/bg-15-3331-2018, https://doi.org/10.5194/bg-15-3331-2018, 2018
Sofia Saraiva, H. E. Markus Meier, Helén Andersson, Anders Höglund, Christian Dieterich, Robinson Hordoir, and Kari Eilola
Earth Syst. Dynam. Discuss., https://doi.org/10.5194/esd-2018-16, https://doi.org/10.5194/esd-2018-16, 2018
Revised manuscript not accepted
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Sayaka Yasunaka, Eko Siswanto, Are Olsen, Mario Hoppema, Eiji Watanabe, Agneta Fransson, Melissa Chierici, Akihiko Murata, Siv K. Lauvset, Rik Wanninkhof, Taro Takahashi, Naohiro Kosugi, Abdirahman M. Omar, Steven van Heuven, and Jeremy T. Mathis
Biogeosciences, 15, 1643–1661, https://doi.org/10.5194/bg-15-1643-2018, https://doi.org/10.5194/bg-15-1643-2018, 2018
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Malin Ödalen, Jonas Nycander, Kevin I. C. Oliver, Laurent Brodeau, and Andy Ridgwell
Biogeosciences, 15, 1367–1393, https://doi.org/10.5194/bg-15-1367-2018, https://doi.org/10.5194/bg-15-1367-2018, 2018
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We conclude that different initial states for an ocean model result in different capacities for ocean carbon storage due to differences in the ocean circulation state and the origin of the carbon in the initial ocean carbon reservoir. This could explain why it is difficult to achieve comparable responses of the ocean carbon system in model inter-comparison studies in which the initial states vary between models. We show that this effect of the initial state is quantifiable.
Tommaso Tesi, Marc C. Geibel, Christof Pearce, Elena Panova, Jorien E. Vonk, Emma Karlsson, Joan A. Salvado, Martin Kruså, Lisa Bröder, Christoph Humborg, Igor Semiletov, and Örjan Gustafsson
Ocean Sci., 13, 735–748, https://doi.org/10.5194/os-13-735-2017, https://doi.org/10.5194/os-13-735-2017, 2017
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Recent Arctic studies suggest that sea-ice decline and permafrost thawing will affect the phytoplankton in the Arctic Ocean. However, in what way the plankton composition will change as the warming proceeds remains elusive. Here we show that the carbon composition of plankton might change as a function of the enhanced terrestrial organic carbon supply and progressive sea-ice thawing.
Per Pemberton, Ulrike Löptien, Robinson Hordoir, Anders Höglund, Semjon Schimanke, Lars Axell, and Jari Haapala
Geosci. Model Dev., 10, 3105–3123, https://doi.org/10.5194/gmd-10-3105-2017, https://doi.org/10.5194/gmd-10-3105-2017, 2017
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The Baltic Sea is seasonally ice covered with intense wintertime ship traffic and a sensitive ecosystem. Understanding the sea-ice pack is important for climate effect studies and forecasting. A NEMO-LIM3.6-based model setup for the North Sea/Baltic Sea is introduced, including a method for ice in the coastal zone. We evaluate different sea-ice parameters and overall find that the model agrees well with the observation though deformed ice is more challenging to capture.
Erik Gustafsson, Christoph Humborg, Göran Björk, Christian Stranne, Leif G. Anderson, Marc C. Geibel, Carl-Magnus Mörth, Marcus Sundbom, Igor P. Semiletov, Brett F. Thornton, and Bo G. Gustafsson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-115, https://doi.org/10.5194/bg-2017-115, 2017
Preprint withdrawn
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In this study we quantify key carbon cycling processes on the East Siberian Arctic Shelf. A specific aim is to determine the pathways of terrestrial organic carbon (OC) supplied by rivers and coastline erosion – and particularly to what extent degradation of terrestrial OC contributes to air-sea CO2 exchange. We estimate that the shelf is a weak CO2 sink, although this sink is considerably reduced mainly by degradation of eroded OC and to a lesser extent by degradation of riverine OC.
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.
D. C. E. Bakker, B. Pfeil, K. Smith, S. Hankin, A. Olsen, S. R. Alin, C. Cosca, S. Harasawa, A. Kozyr, Y. Nojiri, K. M. O'Brien, U. Schuster, M. Telszewski, B. Tilbrook, C. Wada, J. Akl, L. Barbero, N. R. Bates, J. Boutin, Y. Bozec, W.-J. Cai, R. D. Castle, F. P. Chavez, L. Chen, M. Chierici, K. Currie, H. J. W. de Baar, W. Evans, R. A. Feely, A. Fransson, Z. Gao, B. Hales, N. J. Hardman-Mountford, M. Hoppema, W.-J. Huang, C. W. Hunt, B. Huss, T. Ichikawa, T. Johannessen, E. M. Jones, S. D. Jones, S. Jutterström, V. Kitidis, A. Körtzinger, P. Landschützer, S. K. Lauvset, N. Lefèvre, A. B. Manke, J. T. Mathis, L. Merlivat, N. Metzl, A. Murata, T. Newberger, A. M. Omar, T. Ono, G.-H. Park, K. Paterson, D. Pierrot, A. F. Ríos, C. L. Sabine, S. Saito, J. Salisbury, V. V. S. S. Sarma, R. Schlitzer, R. Sieger, I. Skjelvan, T. Steinhoff, K. F. Sullivan, H. Sun, A. J. Sutton, T. Suzuki, C. Sweeney, T. Takahashi, J. Tjiputra, N. Tsurushima, S. M. A. C. van Heuven, D. Vandemark, P. Vlahos, D. W. R. Wallace, R. Wanninkhof, and A. J. Watson
Earth Syst. Sci. Data, 6, 69–90, https://doi.org/10.5194/essd-6-69-2014, https://doi.org/10.5194/essd-6-69-2014, 2014
M. Mattsdotter Björk, A. Fransson, A. Torstensson, and M. Chierici
Biogeosciences, 11, 57–73, https://doi.org/10.5194/bg-11-57-2014, https://doi.org/10.5194/bg-11-57-2014, 2014
Related subject area
Biogeochemistry: Coastal Ocean
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
Quantification and mitigation of bottom trawling impacts on sedimentary organic carbon stocks in the North Sea
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
Ocean alkalinity enhancement using sodium carbonate salts does not impact Fe dynamics in a mesocosm experiment
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
Picoplanktonic methane production in eutrophic surface waters
Influence of Ocean Alkalinity Enhancement with Olivine or Steel Slag on a Coastal Plankton Community in Tasmania
Multiple nitrogen sources for primary production inferred from δ13C and δ15N in the southern Sea of Japan
Influence of manganese cycling on alkalinity in the redox stratified water column of Chesapeake Bay
Estuarine flocculation dynamics of organic carbon and metals from boreal acid sulfate soils
Drivers of particle sinking velocities in the Peruvian upwelling system
Intra-scenario variability of trends and controls of near-bed oxygen concentration on the Northwest European Continental Shelf under climate change
Impacts and uncertainties of climate-induced changes in watershed inputs on estuarine hypoxia
Considerations for hypothetical carbon dioxide removal via alkalinity addition in the Amazon River watershed
High metabolism and periodic hypoxia associated with drifting macrophyte detritus in the shallow subtidal Baltic Sea
Production and accumulation of reef framework by calcifying corals and macroalgae on a remote Indian Ocean cay
Zooplankton community succession and trophic links during a mesocosm experiment in the coastal upwelling off Callao Bay (Peru)
Temporal and spatial evolution of bottom-water hypoxia in the St Lawrence estuarine system
Significant nutrient consumption in the dark subsurface layer during a diatom bloom: a case study on Funka Bay, Hokkaido, Japan
Contrasts in dissolved, particulate, and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf
Sediment quality assessment in an industrialized Greek coastal marine area (western Saronikos Gulf)
Limits and CO2 equilibration of near-coast alkalinity enhancement
Role of phosphorus in the seasonal deoxygenation of the East China Sea shelf
Interannual variability of the initiation of the phytoplankton growing period in two French coastal ecosystems
Spatio-temporal distribution, photoreactivity and environmental control of dissolved organic matter in the sea-surface microlayer of the eastern marginal seas of China
Metabolic alkalinity release from large port facilities (Hamburg, Germany) and impact on coastal carbon storage
A Numerical reassessment of the Gulf of Mexico carbon system in connection with the Mississippi River and global ocean
Observed and projected global warming pressure on coastal hypoxia
Benthic alkalinity fluxes from coastal sediments of the Baltic and North seas: comparing approaches and identifying knowledge gaps
Investigating the effect of nickel concentration on phytoplankton growth to assess potential side-effects of ocean alkalinity enhancement
Unprecedented summer hypoxia in southern Cape Cod Bay: an ecological response to regional climate change?
Interannual variabilities, long-term trends, and regulating factors of low-oxygen conditions in the coastal waters off Hong Kong
Causes of the extensive hypoxia in the Gulf of Riga in 2018
Trawling effects on biogeochemical processes are mediated by fauna in high-energy biogenic-reef-inhabited coastal sediments
Drought recorded by Ba∕Ca in coastal benthic foraminifera
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.
Lucas Porz, Wenyan Zhang, Nils Gerrit Christiansen, Jan Kossack, Ute Daewel, and Corinna Schrum
EGUsphere, https://doi.org/10.5194/egusphere-2024-399, https://doi.org/10.5194/egusphere-2024-399, 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.
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.
David González-Santana, María Segovia, Melchor González-Dávila, Librada Ramírez, Aridane G. González, Leonardo J. Pozzo, Veronica Arnone, Victor Vázquez, Ulf Riebesell, and J. Magdalena Santana-Casiano
EGUsphere, https://doi.org/10.5194/egusphere-2023-2868, https://doi.org/10.5194/egusphere-2023-2868, 2023
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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.
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.
Sandy E. Tenorio and Laura Farías
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-185, https://doi.org/10.5194/bg-2023-185, 2023
Revised manuscript accepted for BG
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Time series studies show that CH4 is highly dynamic on the coastal ocean surface and that planktonic communities are linked to CH4 accumulation as is found in coastal upwelling off Central Chile. We’ve identified the crucial role of picoplankton (>3μm) in CH4 recycling, especially with the addition of methylated substrates (TMA and MPn) during upwelling and non-upwelling periods. These insights improve understanding of surface ocean CH4 recycling, aiding accurate CH4 emissions estimates.
Jiaying A. Guo, Robert F. Strzepek, Kerrie M. Swadling, Ashley T. Townsend, and Lennart T. Bach
EGUsphere, https://doi.org/10.5194/egusphere-2023-2120, https://doi.org/10.5194/egusphere-2023-2120, 2023
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Ocean alkalinity enhancement (OAE) aims to increase atmospheric CO2 sequestration in the oceans by spreading ground alkaline materials into the ocean. To assess the environmental impacts of OAE, we used 53 L microcosms to test how coastal plankton communities respond to OAE with olivine or steel slag as alkalinity sources. Overall, steel slag is much more efficient for CO2 removal than olivine and appears to be induce less changes in the phytoplankton and zooplankton communities.
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.
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.
Giovanni Galli, Sarah Wakelin, James Harle, Jason Holt, and Yuri Artioli
EGUsphere, https://doi.org/10.5194/egusphere-2023-1049, https://doi.org/10.5194/egusphere-2023-1049, 2023
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In this work we looked at the projected change in bottom water oxygen content in an ensemble of ocean climate change models of the North Western European Shelf. What emerged is that, 1. oxygen decreases in all models, 2. in the models with the most warming, a change in circulation patterns is tied to the emergence of low oxygen hotspots in the Eastern North Sea, and, 3. in relatively shallow coastal areas increasing in primary production partially mitigates oxygen decline.
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.
Zheng Chen, Bin Wang, Chuang Xu, Zhongren Zhang, Shiyu Li, and Jiatang Hu
Biogeosciences, 19, 3469–3490, https://doi.org/10.5194/bg-19-3469-2022, https://doi.org/10.5194/bg-19-3469-2022, 2022
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Deterioration of low-oxygen conditions in the coastal waters off Hong Kong was revealed by monitoring data over two decades. The declining wind forcing and the increasing nutrient input contributed significantly to the areal expansion and intense deterioration of low-oxygen conditions. Also, the exacerbated eutrophication drove a shift in the dominant source of organic matter from terrestrial inputs to in situ primary production, which has probably led to an earlier onset of hypoxia in summer.
Stella-Theresa Stoicescu, Jaan Laanemets, Taavi Liblik, Māris Skudra, Oliver Samlas, Inga Lips, and Urmas Lips
Biogeosciences, 19, 2903–2920, https://doi.org/10.5194/bg-19-2903-2022, https://doi.org/10.5194/bg-19-2903-2022, 2022
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Coastal basins with high input of nutrients often suffer from oxygen deficiency. In summer 2018, the extent of oxygen depletion was exceptional in the Gulf of Riga. We analyzed observational data and found that extensive oxygen deficiency appeared since the water layer close to the seabed, where oxygen is consumed, was separated from the surface layer. The problem worsens if similar conditions restricting vertical transport of oxygen occur more frequently in the future.
Justin C. Tiano, Jochen Depestele, Gert Van Hoey, João Fernandes, Pieter van Rijswijk, and Karline Soetaert
Biogeosciences, 19, 2583–2598, https://doi.org/10.5194/bg-19-2583-2022, https://doi.org/10.5194/bg-19-2583-2022, 2022
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This study gives an assessment of bottom trawling on physical, chemical, and biological characteristics in a location known for its strong currents and variable habitats. Although trawl gears only removed the top 1 cm of the seabed surface, impacts on reef-building tubeworms significantly decreased carbon and nutrient cycling. Lighter trawls slightly reduced the impact on fauna and nutrients. Tubeworms were strongly linked to biogeochemical and faunal aspects before but not after trawling.
Inda Brinkmann, Christine Barras, Tom Jilbert, Tomas Næraa, K. Mareike Paul, Magali Schweizer, and Helena L. Filipsson
Biogeosciences, 19, 2523–2535, https://doi.org/10.5194/bg-19-2523-2022, https://doi.org/10.5194/bg-19-2523-2022, 2022
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The concentration of the trace metal barium (Ba) in coastal seawater is a function of continental input, such as riverine discharge. Our geochemical records of the severely hot and dry year 2018, and following wet year 2019, reveal that prolonged drought imprints with exceptionally low Ba concentrations in benthic foraminiferal calcium carbonates of coastal sediments. This highlights the potential of benthic Ba / Ca to trace past climate extremes and variability in coastal marine records.
Cited articles
Aarnos, H., Ylöstalo, P., and Vähätalo, A. V.: Seasonal
phototransformation of dissolved organic matter to ammonium, dissolved
inorganic carbon, and labile substrates supporting bacterial biomass across
the Baltic Sea, J. Geophys. Res.-Biogeo., 117,
https://doi.org/10.1029/2010JG001633, 2012. a, b
Alling, V., Humborg, C., Mörth, C.-M., Rahm, L., and Pollehne, F.: Tracing
terrestrial organic matter by δ34 and δ13C
signatures in a subarctic estuary, Limnol. Oceanogr., 53,
2594–2602, https://doi.org/10.4319/lo.2008.53.6.2594, 2008. a, b
Anderson, L. G., Jutterström, S., Hjalmarsson, S., Wåhlström, I.,
and Semiletov, I. P.: Out-gassing of CO2 from Siberian Shelf seas by
terrestrial organic matter decomposition, Geophys. Res. Lett.,
36, L20601,
https://doi.org/10.1029/2009GL040046, 2009. a
Ask, J., Karlsson, J., Persson, L., Ask, P., Byström, P., and Jansson, M.:
Terrestrial organic matter and light penetration: Effects on bacterial and
primary production in lakes, Limnol. Oceanogr., 54, 2034–2040,
https://doi.org/10.4319/lo.2009.54.6.2034, 2009. a, b
Asmala, E., Autio, R., Kaartokallio, H., Pitkänen, L., Stedmon, C. A., and
Thomas, D. N.: Bioavailability of riverine dissolved organic matter in three
Baltic Sea estuaries and the effect of catchment land use, Biogeosciences,
10, 6969–6986, https://doi.org/10.5194/bg-10-6969-2013, 2013. a, b, c
Asmala, E., Autio, R., Kaartokallio, H., Stedmon, C. A., and Thomas, D. N.:
Processing of humic-rich riverine dissolved organic matter by estuarine
bacteria: effects of predegradation and inorganic nutrients, Aquat.
Sci., 76, 451–463, https://doi.org/10.1007/s00027-014-0346-7, 2014a. a, b, c, d
Asmala, E., Bowers, D. G., Autio, R., Kaartokallio, H., and Thomas, D. N.:
Qualitative changes of riverine dissolved organic matter at low salinities
due to flocculation, J. Geophys. Res.-Biogeo., 119,
1919–1933, https://doi.org/10.1002/2014JG002722, 2014b. a, b
Asmala, E., Carstensen, J., Conley, D. J., Slomp, C. P., Stadmark, J., and
Voss, M.: Efficiency of the coastal filter: Nitrogen and phosphorus removal
in the Baltic Sea, Limnol. Oceanogr., 62, S222–S238,
https://doi.org/10.1002/lno.10644, 2017. a
Bauer, J. E., Cai, W.-J., Raymond, P. A., Bianchi, T. S., Hopkinson, C. S., and
Regnier, P. A. G.: The changing carbon cycle of the coastal ocean, Nature,
504, 61–70, https://doi.org/10.1038/nature12857, 2013. a
Benner, R. and Kaiser, K.: Biological and photochemical transformations of
amino acids and lignin phenols in riverine dissolved organic matter,
Biogeochemistry, 102, 209–222, https://doi.org/10.1007/s10533-010-9435-4, 2011. a
BFM Consortium: Biogeochemical Flux Model, available at:
http://bfm-community.eu, last access: 11 February 2019. a
Bianchi, T. S.: The role of terrestrially derived organic carbon in the coastal
ocean: A changing paradigm and the priming effect, P.
Natl. Acad. Sci. USA, 108, 19473, https://doi.org/10.1073/pnas.1017982108, 2011. a
Blair, N. E. and Aller, R. C.: The Fate of Terrestrial Organic Carbon in the
Marine Environment, Annu. Rev. Mar. Sci., 4, 401–423,
https://doi.org/10.1146/annurev-marine-120709-142717, 2011. a
Blair, N. E. and Aller, R. C.: The Fate of Terrestrial Organic Carbon in the
Marine Environment, Annu. Rev. Mar. Sci., 4, 401–423,
https://doi.org/10.1146/annurev-marine-120709-142717, 2012. a
Borges, A. V., Delille, B., and Frankignoulle, M.: Budgeting sinks and
sources of CO2 in the coastal ocean: Diversity of ecosystems counts,
Geophys. Res. Lett., 32, L14601, https://doi.org/10.1029/2005GL023053, 2005. a
Bratbak, G. and Thingstad, T. F.: Phytoplankton-bacteria interactions: an
apparent paradox? Analysis of a model system with both competition and
commensalisms, Mar. Ecol. Prog. Ser., 25, 23–30, 1985. a
Cai, W.-J.: Estuarine and Coastal Ocean Carbon Paradox: CO2 Sinks or Sites of
Terrestrial Carbon Incineration?, Annu. Rev. Mar. Sci., 3,
123–145, https://doi.org/10.1146/annurev-marine-120709-142723, 2011. a
Carlson, C. A., Hansell, D. A., Hansell, D. A., and Carlson, C. A.: Chapter 3 –
DOM Sources, Sinks, Reactivity, and Budgets, Academic Press,
Boston, MA, USA, 65–126, https://doi.org/10.1016/B978-0-12-405940-5.00003-0, 2015. a, b
Dittmar, T. and Kattner, G.: The biogeochemistry of the river and shelf
ecosystem of the Arctic Ocean: a review, Mar. Chem., 83, 103–120,
https://doi.org/10.1016/S0304-4203(03)00105-1, 2003. a
Donnelly, C., Andersson, J. C., and Arheimer, B.: Using flow signatures and
catchment similarities to evaluate the E-HYPE multi-basin model across
Europe, Hydrolog. Sci. J., 61, 255–273,
https://doi.org/10.1080/02626667.2015.1027710, 2016. a
Fichot, C. G. and Benner, R.: The fate of terrigenous dissolved organic carbon
in a river-influenced ocean margin, Global Biogeochem. Cy., 28,
300–318, https://doi.org/10.1002/2013GB004670, 2014. a
Figueroa, D., Rowe, O. F., Paczkowska, J., Legrand, C., and Andersson, A.:
Allochthonous Carbon – a Major Driver of Bacterioplankton Production in the
Subarctic Northern Baltic Sea, Microb. Ecol., 71, 789–801,
https://doi.org/10.1007/s00248-015-0714-4, 2016. a, b, c
Frankignoulle, M., Abril, G., Borges, A., Bourge, I., Canon, C., Delille, B.,
Libert, E., and Théate, J.-M.: Carbon Dioxide Emission from European
Estuaries, Science, 282, 434–436, https://doi.org/10.1126/science.282.5388.434, 1998. a
Fransner, F., Gustafsson, E., Tedesco, L., Vichi, M., Hordoir, R., Roquet, F.,
Spilling, K., Kuznetsov, I., Eilola, K., Mörth, C.-M., Humborg, C., and
Nycander, J.: Non-Redfieldian Dynamics Explain Seasonal pCO2 Drawdown in the
Gulf of Bothnia, J. Geophys. Res.-Oceans, 123, 166–188,
https://doi.org/10.1002/2017JC013019, 2018. a, b, c, d, e, f, g, h, i, j
Fransson, A., Anderson, L., Andreasson, K., Johansson, S., Karlson, B.,
Kronsell, J., Stranne, C., Sahlsten, E., and Willstrand-Wranne, A.: Seasonal
and spatial variability of the surface-water fCO2 in the
Baltic Sea and Skagerrak-Kattegat: implications for ocean acidification, in
preparation, 2019. a, b
Gustafsson, E., Deutsch, B., Gustafsson, B., Humborg, C., and Mörth, C.-M.:
Carbon cycling in the Baltic Sea – The fate of allochthonous organic carbon
and its impact on air–sea CO2 exchange, J. Mar. Syst., 129, 289–302, https://doi.org/10.1016/j.jmarsys.2013.07.005, 2014. a
Hansell, D. A.: Recalcitrant Dissolved Organic Carbon Fractions, Annu. Rev.
Mar. Sci., 5, 421–445, https://doi.org/10.1146/annurev-marine-120710-100757, 2013. a, b
Herlemann, D. P. R., Manecki, M., Meeske, C., Pollehne, F., Labrenz, M.,
Schulz-Bull, D., Dittmar, T., and Jürgens, K.: Uncoupling of Bacterial
and Terrigenous Dissolved Organic Matter Dynamics in Decomposition
Experiments, PLOS ONE, 9, 1–12, https://doi.org/10.1371/journal.pone.0093945, 2014. a, b, c, d
Hessen, D. O., Carroll, J., Kjeldstad, B., Korosov, A. A., Pettersson, L. H.,
Pozdnyakov, D., and Sørensen, K.: Input of organic carbon as determinant
of nutrient fluxes, light climate and productivity in the Ob and Yenisey
estuaries, Estuar. Coast. Shelf S., 88, 53–62,
https://doi.org/10.1016/j.ecss.2010.03.006, 2010. a
Hoikkala, L., Kortelainen, P., Soinne, H., and Kuosa, H.: Dissolved organic
matter in the Baltic Sea, J. Marine Syst., 142, 47–61,
https://doi.org/10.1016/j.jmarsys.2014.10.005, 2015. a
Hordoir, R., Dieterich, C., Basu, C., Dietze, H., and Meier, H.: Freshwater
outflow of the Baltic Sea and transport in the Norwegian current: A
statistical correlation analysis based on a numerical experiment, Cont.
Shelf Res., 64, 1–9, https://doi.org/10.1016/j.csr.2013.05.006, 2013. a
Hordoir, R., Axell, L., Löptien, U., Dietze, H., and Kuznetsov, I.:
Influence of sea level rise on the dynamics of salt inflows in the Baltic
Sea, J. Geophys. Res.-Oceans, 120, 6653–6668,
https://doi.org/10.1002/2014JC010642, 2015. a
Hordoir, R., Axell, L., Höglund, A., Dieterich, C., Fransner, F.,
Gröger, M., Liu, Y., Pemberton, P., Schimanke, S., Andersson, H.,
Ljungemyr, P., Nygren, P., Falahat, S., Nord, A., Jönsson, A., Lake, I.,
Döös, K., Hieronymus, M., Dietze, H., Löptien, U., Kuznetsov, I.,
Westerlund, A., Tuomi, L., and Haapala, J.: Nemo-Nordic 1.0: a NEMO-based
ocean model for the Baltic and North seas – research and operational
applications, Geosci. Model Dev., 12, 363–386,
https://doi.org/10.5194/gmd-12-363-2019, 2019. a
Hulatt, C. J., Kaartokallio, H., Asmala, E., Autio, R., Stedmon, C. A.,
Sonninen, E., Oinonen, M., and Thomas, D. N.: Bioavailability and radiocarbon
age of fluvial dissolved organic matter (DOM) from a northern
peatland-dominated catchment: effect of land-use change, Aquat. Sci.,
76, 393–404, https://doi.org/10.1007/s00027-014-0342-y, 2014. a, b, c, d
ICES: ICES Baltic Sea monitoring data, International Council for the
Exploration of the Sea, available at:
http://ocean.ices.dk/Helcom/Helcom.aspx?Mode=1, last access: 11
February 2019. a
Joint, I., Henriksen, P., Fonnes, G. A., Bourne, D., Thingstad, T. F., and
Riemann, B.: Competition for inorganic nutrients between phytoplankton and
bacterioplankton in nutrient manipulated mesocosms, Aquat. Microb.
Ecol., 29, 145–159,
https://www.int-res.com/abstracts/ame/v29/n2/p145-159/ (last access: 11 February 2019), 2002. a
Kuliński, K., Hammer, K., Schneider, B., and Schulz-Bull, D.:
Remineralization of terrestrial dissolved organic carbon in the Baltic Sea,
Mar. Chem., 181, 10–17,
https://doi.org/10.1016/j.marchem.2016.03.002, 2016. a
Löffler, A., Schneider, B., Perttilä, M., and Rehder, G.: Air–sea
CO2
exchange in the Gulf of Bothnia, Baltic Sea, Cont. Shelf Res., 37,
46–56, https://doi.org/10.1016/j.csr.2012.02.002, 2012. a, b, c, d
Madec, G. and the NEMO team: Nemo ocean engine, version 3.6 stable, Note du
Pole de modélisation, Institut Pierre-Simon Laplace (IPSL), Paris, France, no.
27, issn no. 1288-1619 edn., 2016. a
Mantoura, R. and Woodward, E.: Conservative behaviour of riverine dissolved
organic carbon in the Severn Estuary: chemical and geochemical implications,
Geochim. Cosmochim. Ac., 47, 1293– 309,
https://doi.org/10.1016/0016-7037(83)90069-8, 1983. a
NEMO Consortium: NEMO community ocean model, available at:
http://www.nemo-ocean.eu, last access: 11 February 2019. a
Pemberton, P., Löptien, U., Hordoir, R., Höglund, A., Schimanke, S., Axell,
L., and Haapala, J.: Sea-ice evaluation of NEMO-Nordic 1.0: a
NEMO–LIM3.6-based ocean–sea-ice model setup for the North Sea and Baltic Sea,
Geosci. Model Dev., 10, 3105–3123, https://doi.org/10.5194/gmd-10-3105-2017,
2017. a
Pierrot, D., Neill, C., Sullivan, K., Castle, R., Wanninkhof, R., Lüger,
H., Johannessen, T., Olsen, A., Feely, R. A., and Cosca, C. E.:
Recommendations for autonomous underway pCO2 measuring systems and
data-reduction routines, Deep-Sea Res. Pt. II, 56, 512–522,
https://doi.org/10.1016/j.dsr2.2008.12.005, 2009. a, b
Raymond, P. A., Bauer, J. E., and Cole, J. J.: Atmospheric CO2 evasion,
dissolved inorganic carbon production, and net heterotrophy in the York River
estuary, Limnol. Oceanogr., 45, 1707–1717,
https://doi.org/10.4319/lo.2000.45.8.1707, 2000. a
Samuelsson, P., Jones, C. G., Willén, U., Ullerstig, A., Gollvik, S.,
Hansson, U., Jansson, C., Kjellström, E., Nikulin, G., and Wyser, K.: The
Rossby Centre Regional Climate model RCA3: model description and performance,
Tellus A, 63, 4–23, https://doi.org/10.1111/j.1600-0870.2010.00478.x, 2011. a
Sandberg, J., Andersson, A., Johansson, S., and Wikner, J.: Pelagic food web
structure and carbon budget in the northern Baltic Sea: potential importance
of terrigenous carbon, Mar. Ecol. Prog. Ser., 268, 13–29,
https://www.int-res.com/abstracts/meps/v268/p13-29/ (last access: 11 February 2019), 2004. a, b, c
Seidel, M., Manecki, M., Herlemann, D. P. R., Deutsch, B., Schulz-Bull, D.,
Jürgens, K., and Dittmar, T.: Composition and Transformation of Dissolved
Organic Matter in the Baltic Sea, Front. Earth Sci., 5, 31, https://doi.org/10.3389/feart.2017.00031, 2017. a
Silvennoinen, H., Liikanen, A., Torssonen, J., Stange, C. F., and Martikainen,
P. J.: Denitrification and N2O effluxes in the Bothnian Bay (northern Baltic
Sea) river sediments as affected by temperature under different oxygen
concentrations, Biogeochemistry, 88, 63–72, https://doi.org/10.1007/s10533-008-9194-7, 2008. a
Stepanauskas, R., JØrgensen, N. O. G., Eigaard, O. R., Žvikas, A.,
Tranvik, L. J., and Leonardson, L.: Summer inputs of riverine nutrients to
the Baltic Sea: bioavailability and eutrophication relevance, Ecol.
Monogr., 72, 579–597,
https://doi.org/10.1890/0012-9615(2002)072[0579:SIORNT]2.0.CO;2, 2002. a
Thingstad, T. F., Bellerby, R. G. J., Bratbak, G., Børsheim, K. Y., Egge,
J. K., Heldal, M., Larsen, A., Neill, C., Nejstgaard, J., Norland, S.,
Sandaa, R. A., Skjoldal, E. F., Tanaka, T., Thyrhaug, R., and Töpper, B.:
Counterintuitive carbon-to-nutrient coupling in an Arctic pelagic ecosystem,
Nature, 455, 387–390, https://doi.org/10.1038/nature07235,
2008. a
Vähätalo, A., Aarnos, H., Hoikkala, L., and Lignell, R.: Photochemical
transformation of terrestrial dissolved organic matter supports hetero- and
autotrophic production in coastal waters, Mar. Ecol. Prog. Ser.,
423, 1–14,
https://www.int-res.com/abstracts/meps/v423/p1-14/ (last access: 11 February 2019), 2011. a
Vancoppenolle, M., Fichefet, T., Goosse, H., Bouillon, S., Madec, G., and
Maqueda, M. A. M.: Simulating the mass balance and salinity of Arctic and
Antarctic sea ice, 1. Model description and validation, Ocean Model., 27,
33–53, https://doi.org/10.1016/j.ocemod.2008.10.005, 2009. a
Vichi, M., Pinardi, N., and Masina, S.: A generalized model of pelagic
biogeochemistry for the global ocean ecosystem, Part I: Theory, J.
Marine Syst., 64, 89–109,
https://doi.org/10.1016/j.jmarsys.2006.03.006, contributions from Advances in Marine Ecosystem Modelling Research,
27-29 June, 2005, Plymouth, UK, 2007. a
Vichi, M., Lovato, T., Lazzari, P., Cossarini, G., Gutierrez Mlot, E., Mattia,
G., Masina, S., McKiver, W. J., Pinardi, N., Solidoro, C., Tedesco, L., and
Zavatarelli, M.: The Biogeochemical Flux Model (BFM): Equation Description
and User Manual, BFM version 5.1, BFM Consortium, 2015. a
Wikner, J. and Andersson, A.: Increased freshwater discharge shifts the trophic
balance in the coastal zone of the northern Baltic Sea, Global Change
Biol., 18, 2509–2519, https://doi.org/10.1111/j.1365-2486.2012.02718.x, 2012. a
Winogradow, A. and Pempkowiak, J.: Organic carbon burial rates in the Baltic
Sea sediments, Estuar. Coast. Shelf S., 138, 27–36,
https://doi.org/10.1016/j.ecss.2013.12.001, 2014.
a
Zweifel, U. L., Wikner, J., Hagström, Å., Lundberg, E., and Norrman,
B.: Dynamics of dissolved organic carbon in a coastal ecosystem, Limnol. Oceanogr., 40, 299–305, https://doi.org/10.4319/lo.1995.40.2.0299, 1995. a
Short summary
Although rivers carry large amounts of organic material to the oceans, little is known about what fate it meets when it reaches the sea. In this study we are investigating the fate of the carbon in this organic matter by the use of a numerical model in combination with ship measurements from the northern Baltic Sea. Our results suggests that there is substantial remineralization taking place, transforming the organic carbon into CO2, which is released to the atmosphere.
Although rivers carry large amounts of organic material to the oceans, little is known about...
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