Articles | Volume 17, issue 10
https://doi.org/10.5194/bg-17-2745-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-17-2745-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
24 May 2020
Research article |
| 24 May 2020
| 24 May 2020
Removal of phosphorus and nitrogen in sediments of the eutrophic Stockholm archipelago, Baltic Sea
Niels A. G. M. van Helmond
CORRESPONDING AUTHOR
Department of Earth Sciences, Faculty of Geosciences, Utrecht
University, Princetonlaan 8a, 3584 CB Utrecht, the Netherlands
Department of Geology, Lund University, Sölvegatan 12, 223 62
Lund, Sweden
Department of Microbiology, Institute for Water and Wetland Research,
Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
Elizabeth K. Robertson
Department of Geology, Lund University, Sölvegatan 12, 223 62
Lund, Sweden
Department of Marine Sciences, University of Gothenburg, Box 461,
40530 Gothenburg, Sweden
Daniel J. Conley
Department of Geology, Lund University, Sölvegatan 12, 223 62
Lund, Sweden
Martijn Hermans
Department of Earth Sciences, Faculty of Geosciences, Utrecht
University, Princetonlaan 8a, 3584 CB Utrecht, the Netherlands
Christoph Humborg
Baltic Sea Centre, Stockholm University, 106 91 Stockholm, Sweden
L. Joëlle Kubeneck
Department of Earth Sciences, Faculty of Geosciences, Utrecht
University, Princetonlaan 8a, 3584 CB Utrecht, the Netherlands
now at: Institute of Biogeochemistry and Pollutant Dynamics,
Department of Environmental Systems Science, ETH Zürich,
Universitätstrasse 16, 8092 Zürich, Switzerland
Wytze K. Lenstra
Department of Earth Sciences, Faculty of Geosciences, Utrecht
University, Princetonlaan 8a, 3584 CB Utrecht, the Netherlands
Caroline P. Slomp
Department of Earth Sciences, Faculty of Geosciences, Utrecht
University, Princetonlaan 8a, 3584 CB Utrecht, the Netherlands
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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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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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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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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
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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
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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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Raquel Vaquer-Sunyer, Heather E. Reader, Saraladevi Muthusamy, Markus V. Lindh, Jarone Pinhassi, Daniel J. Conley, and Emma S. Kritzberg
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Niels A. G. M. van Helmond, Appy Sluijs, Nina M. Papadomanolaki, A. Guy Plint, Darren R. Gröcke, Martin A. Pearce, James S. Eldrett, João Trabucho-Alexandre, Ireneusz Walaszczyk, Bas van de Schootbrugge, and Henk Brinkhuis
Biogeosciences, 13, 2859–2872, https://doi.org/10.5194/bg-13-2859-2016, https://doi.org/10.5194/bg-13-2859-2016, 2016
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Over the past decades large changes have been observed in the biogeographical dispersion of marine life resulting from climate change. To better understand present and future trends it is important to document and fully understand the biogeographical response of marine life during episodes of environmental change in the geological past.
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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
W. Clymans, L. Barão, N. Van der Putten, S. Wastegård, G. Gísladóttir, S. Björck, B. Moine, E. Struyf, and D. J. Conley
Biogeosciences, 12, 3789–3804, https://doi.org/10.5194/bg-12-3789-2015, https://doi.org/10.5194/bg-12-3789-2015, 2015
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Biogenic silica (BSi) is used as a proxy by soil scientists to identify biological effects on the Si cycle and by palaeoecologists to study environmental changes. We show the presence of tephra constituents can make measurements erroneous at low BSi concentrations, with repercussions for soil and palaeoecological studies. However, we also show that glass shards do not produce an identical dissolution signal to that of BSi, meaning they can be distinguished with appropriate experimental setups.
N. A. G. M. van Helmond, A. Sluijs, J. S. Sinninghe Damsté, G.-J. Reichart, S. Voigt, J. Erbacher, J. Pross, and H. Brinkhuis
Clim. Past, 11, 495–508, https://doi.org/10.5194/cp-11-495-2015, https://doi.org/10.5194/cp-11-495-2015, 2015
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Based on the chemistry and microfossils preserved in sediments deposited in a shallow sea, in the current Lower Saxony region (NW Germany), we conclude that changes in Earth’s orbit around the Sun led to enhanced rainfall and organic matter production. The additional supply of organic matter, depleting oxygen upon degradation, and freshwater, inhibiting the mixing of oxygen-rich surface waters with deeper waters, caused the development of oxygen-poor waters about 94 million years ago.
M. Hagens, C. P. Slomp, F. J. R. Meysman, D. Seitaj, J. Harlay, A. V. Borges, and J. J. Middelburg
Biogeosciences, 12, 1561–1583, https://doi.org/10.5194/bg-12-1561-2015, https://doi.org/10.5194/bg-12-1561-2015, 2015
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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.
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
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
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
Biogeochemistry: Coastal Ocean
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
Assessing the impacts of simulated ocean alkalinity enhancement on viability and growth of nearshore species of phytoplankton
Responses of microbial metabolic rates to non-equilibrated silicate- versus calcium-based ocean alkalinity enhancement
High metabolic zinc demand within native Amundsen and Ross sea phytoplankton communities determined by stable isotope uptake rate measurements
The influence of zooplankton and oxygen on the particulate organic carbon flux in the Benguela Upwelling System
Reviews and syntheses: Biological indicators of low-oxygen stress in marine water-breathing animals
Temperature-enhanced effects of iron on Southern Ocean phytoplankton
Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth system model
The Northeast Greenland Shelf as a potential late-summer CO2 source to the atmosphere
Technical note: Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project (OAEPIIP)
Estimates of carbon sequestration potential in an expanding Arctic fjord (Hornsund, Svalbard) affected by dark plumes of glacial meltwater
An assessment of ocean alkalinity enhancement using aqueous hydroxides: kinetics, efficiency, and precipitation thresholds
Dissolved nitric oxide in the lower Elbe Estuary and the Port of Hamburg area
Technical note: New approach for the determination of N2 fixation rates by coupling a membrane equilibrator to a mass spectrometer on voluntary observing ships
Variable contribution of wastewater treatment plant effluents to downstream nitrous oxide concentrations and emissions
Distribution of nutrients and dissolved organic matter in a eutrophic equatorial estuary: the Johor River and the East Johor Strait
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
Reviews and synthesis: increasing hypoxia in eastern boundary upwelling systems: a major stressor for zooplankton
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)
Ocean Alkalinity Enhancement (OAE) does not cause cellular stress in a phytoplankton community of the sub-tropical Atlantic Ocean
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
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
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
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.
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.
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.
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.
Sören Iwe, Oliver Schmale, and Bernd Schneider
EGUsphere, https://doi.org/10.5194/egusphere-2024-2049, https://doi.org/10.5194/egusphere-2024-2049, 2024
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We present a novel method to quantify N2 fixation by cyanobacteria, crucial in Baltic Sea eutrophication. Our Gas Equilibrium – Membrane-Inlet Mass Spectrometer (GE-MIMS), designed for operation on voluntary observing ships (VOS), enables large-scale monitoring of surface water N2 depletion caused by N2 fixation. Laboratory tests confirm the device’s accuracy and precision, ensuring it can complement current methods and contribute valuable data to better understand N2 fixation in the Baltic Sea.
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.
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.
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.
Leissing Frederick, Mauricio A. Urbina, and Ruben Escribano
EGUsphere, https://doi.org/10.5194/egusphere-2024-836, https://doi.org/10.5194/egusphere-2024-836, 2024
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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 populations and the marine food web.
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.
Librada Ramírez, Leonardo J. Pozzo-Pirotta, Aja Trebec, Víctor Manzanares-Vázquez, José L. Díez, Javier Arístegui, Ulf Riebesell, Stephen D. Archer, and María Segovia
EGUsphere, https://doi.org/10.5194/egusphere-2024-847, https://doi.org/10.5194/egusphere-2024-847, 2024
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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 studied plankton community.
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.
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.
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.
Cited articles
Algar, C. K. and Vallino, J. J.: Predicting microbial nitrate reduction
pathways in coastal sediments, Aquat. Microb. Ecol., 71, 223–238,
https://doi.org/10.3354/ame01678, 2014.
Algeo, T. J. and Ingall, E.: Sedimentary Corg: P ratios, paleocean
ventilation, and Phanerozoic atmospheric pO2, Palaeogeogr. Palaeoecol.,
256, 130–155, https://doi.org/10.1016/j.palaeo.2007.02.029, 2007.
Almroth-Rosell, E., Edman, M., Eilola, K., Meier, H. E. M., and Sahlberg, J.: Modelling nutrient retention in the coastal zone of an eutrophic sea, Biogeosciences, 13, 5753–5769, https://doi.org/10.5194/bg-13-5753-2016, 2016.
An, S. and Gardner, W. S.: Dissimilatory nitrate reduction to ammonium
(DNRA) as a nitrogen link, versus denitrification as a sink in a shallow
estuary (Laguna Madre/Baffin Bay, Texas), Mar. Ecol. Prog. Ser., 237, 41–50,
https://doi.org/10.3354/meps237041, 2002.
Anderson, D. M., Glibert, P. M., and Burkholder, J. M.: Harmful algal blooms
and eutrophication: nutrient sources, composition, and consequences,
Estuaries, 25, 704–726, https://doi.org/10.1007/BF02804901, 2002.
Andersen, J. H., Carstensen, J., Conley, D. J., Dromph, K.,
Fleming-Lehtinen, V., Gustafsson, B. G., Josefson, A. B., Norkko, A.,
Villnäs, A., and Murray, C.: Long-term temporal and spatial trends in
eutrophication status of the Baltic Sea, Biol. Rev., 92, 135–149,
https://doi.org/10.1111/brv.12221, 2017.
APHA: Standard methods for the examination of water and wastewater, 11 Edn., Am. J. Public Health, 51, 940, https://doi.org/10.2105/AJPH.51.6.940-a,
2005.
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, 222–238,
https://doi.org/10.1002/lno.10644, 2017.
Asmala, E., Carstensen, J., Conley, D. J., Slomp, C. P., Stadmark, J., and
Voss, M.: A reply to the comment by Karlsson et al., Limnol. Oceanogr., 64,
1832–1833, https://doi.org/10.1002/lno.11195, 2019.
Berg, P., Risgaard-Petersen, N., and Rysgaard, S.: Interpretation of
measured concentration profiles in sediment pore water, Limnol. Oceanogr.,
43, 1500–1510, https://doi.org/10.4319/lo.1998.43.7.1500, 1998.
Boesch, D. F.: Challenges and opportunities for science in reducing nutrient
over-enrichment of coastal ecosystems, Estuaries, 25, 886–900,
https://doi.org/10.1007/BF02804914, 2002.
Bonaglia, S., Bartoli, M, Gunnarsson, J., Rahm, L., Raymond, C., Svensson,
O., Shakeri Yekta, S., and Brüchert, V.: Effect of reoxygenation and
Marenzelleria spp. Bioturbation on Baltic Sea sediment metabolism, Mar.
Ecol. Prog. Ser., 482, 43–55, https://doi.org/10.3354/meps10232, 2013.
Bonaglia, S., Deutsch, B., Bartoli, M., Marchant, H. K., and Brüchert,
V.: Seasonal oxygen, nitrogen and phosphorus benthic cycling along an
impacted Baltic Sea estuary: regulation and spatial patterns,
Biogeochemistry, 119, 139–160, https://doi.org/10.1007/s10533-014-9953-6,
2014.
Bonaglia, S., Hylén, A., Rattray, J. E., Kononets, M. Y., Ekeroth, N., Roos, P., Thamdrup, B., Brüchert, V., and Hall, P. O. J.: The fate of fixed nitrogen in marine sediments with low organic loading: an in situ study, Biogeosciences, 14, 285–300, https://doi.org/10.5194/bg-14-285-2017, 2017.
Bouwman, A. F., Bierkens, M. F. P., Griffioen, J., Hefting, M. M., Middelburg, J. J., Middelkoop, H., and Slomp, C. P.: Nutrient dynamics, transfer and retention along the aquatic continuum from land to ocean: towards integration of ecological and biogeochemical models, Biogeosciences, 10, 1–22, https://doi.org/10.5194/bg-10-1-2013, 2013.
Bower, C. E. and Holm-Hansen, T.: A salicylate–hypochlorite method for
determining ammonia in seawater, Can. J. Fish. Aquat. Sci., 37, 794–798,
https://doi.org/10.1139/f03-113, 1980.
Bryhn, A. C. and Håkanson, L.: Land uplift effects on the phosphorus
cycle of the Baltic Sea, Environ. Earth Sci., 62, 1761–1770,
https://doi.org/10.1007/s12665-010-0656-6, 2011.
Burgin, A. J. and Hamilton, S. K.: Have we overemphasized the role of
denitrification in aquatic ecosystems? A review of nitrate removal pathways,
Front. Ecol. Environ., 5, 89–96,
https://doi.org/10.1890/1540-9295(2007)5[89:HWOTRO]2.0.CO;2, 2007.
Burton, E. D., Sullivan, L. A., Bush, R. T., Johnston, S. G., and Keene, A.
F.: A simple and inexpensive chromium-reducible sulfur method for
acid-sulfate soils, Appl. Geochem., 23, 2759–2766,
https://doi.org/10.1016/j.apgeochem.2008.07.007, 2008.
Carman, R., Aigars, J., and Larsen, B.: Carbon and nutrient geochemistry of
the surface sediments of the Gulf of Riga, Baltic Sea, Mar. Geol., 134,
57–76, https://doi.org/10.1016/0025-3227(96)00033-3, 1996.
Carstensen, J., Sánchez-Camacho, M., Duarte, C. M., Krause-Jensen, D.,
and Marba, N.: Connecting the dots: responses of coastal ecosystems to
changing nutrient concentrations, Environ. Sci. Technol., 45, 9122–9132,
https://doi.org/10.1021/es202351y, 2011.
Christensen, P. B., Rysgaard, S., Sloth, N. P., Dalsgaard, T., and
Schwærter, S.: Sediment mineralization, nutrient fluxes, denitrification
and dissimilatory nitrate reduction to ammonium in an estuarine fjord with
sea cage trout farms, Aquat. Microb. Ecol., 21, 73–84,
https://doi.org/10.3354/ame021073, 2000.
Claff, S. R., Sullivan, L. A., Burton, E. D., and Bush, R. T.: A sequential
extraction procedure for acid sulfate soils: Partitioning of iron, Geoderma,
155, 224–230, https://doi.org/10.1016/j.geoderma.2009.12.002, 2010.
Cline, J. D.: Spectrophotometric determination of hydrogen sulfide in
natural waters, Limnol. Oceanogr., 14, 454–458,
https://doi.org/10.4319/lo.1969.14.3.0454, 1969.
Cloern, J. E.: Our evolving conceptual model of the coastal eutrophication
problem, Mar. Ecol. Prog. Ser., 210, 223–253,
https://doi.org/10.3354/meps210223, 2001.
Conley, D. J., Humborg, C., Rahm, L., Savchuk, O. P., and Wulff, F.: Hypoxia
in the Baltic Sea and basin-scale changes in phosphorus biogeochemistry,
Environ. Sci. Technol., 36, 5315–5320, https://doi.org/10.1021/es025763w,
2002.
Conley, D. J., Carstensen, J., Aigars, J., Are, P., Bonsdorff, E., Eremina,
T., Haahti, B.-M., Humborg, C., Jonsson, P., Kotta, J., Lännegren, C.,
Larsson, U., Maximov, A., Medina, M. R., Lysiak-Pastuszak, E.,
Remekaite-Nikiene, N., Walve, J., Wilhelms, S., and Zillén, L.: Hypoxia
increasing in the coastal zone of the Baltic Sea, Environ. Sci. Technol.,
45, 6777–6783, https://doi.org/10.1021/es201212r, 2011.
Dalsgaard, T., Thamdrup, B., and Canfield, D. E.: Anaerobic ammonium
oxidation (anammox) in the marine environment, Res. Microbiol., 156,
457–464, https://doi.org/10.1016/j.resmic.2005.01.011, 2005.
Dalsgaard, T., De Brabandere, L., and Hall, P. O.: Denitrification in the
water column of the central Baltic Sea, Geochim. Cosmochim. Ac., 106,
247–260, https://doi.org/10.1016/j.gca.2012.12.038, 2013.
Diaz, R. J. and Rosenberg, R.: Spreading dead zones and consequences for
marine ecosystems, Science, 321, 926–929,
https://doi.org/10.1126/science.1156401, 2008.
Dijkstra, N., Kraal, P., Kuypers, M. M. M., Schnetger, B., and Slomp, C. P.:
Are iron-phosphate minerals a sink for phosphorus in anoxic Black Sea
sediments?, PLoS ONE, 9, 1–12, https://doi.org/10.1371/journal.pone.0101139,
2014.
Duarte, C. M., Conley, D. J., Carstensen, J., and Sánchez-Camacho, M.:
Return to Neverland: shifting baselines affect eutrophication restoration
targets, Estuar. Coast., 32, 29–36,
https://doi.org/10.1007/s12237-008-9111-2, 2009.
Edman, M. K., Eilola, K., Almroth-Rosell, E., Meier, H. E.,
Wåhlström, I., and Arneborg, L.: Nutrient retention in the Swedish
coastal zone, Front. Mar. Sci., 5, 415,
https://doi.org/10.3389/fmars.2018.00415, 2018.
Egger, M., Jilbert, T., Behrends, T., Rivard, C., and Slomp, C. P.:
Vivianite is a major sink for phosphorus in methanogenic coastal surface
sediments, Geochim. Cosmochim. Ac., 169, 217–235,
https://doi.org/10.1016/j.gca.2015.09.012, 2015.
Engqvist, A. and Andrejev, O.: Water exchange of the Stockholm archipelago
– a cascade framework modelling approach, J. Sea Res., 49, 275–294,
https://doi.org/10.1016/S1385-1101(03)00023-6, 2003.
Füssel, J., Lam, P., Lavik, G., Jensen, M. M., Holtappels, M.,
Günter, M., and Kuypers, M. M. M.: Nitrite oxidation in the Namibian oxygen
minimum zone, ISME J., 6, 1200–1209,
https://doi.org/10.1038/ismej.2011.178, 2012.
Giblin, A. E., Tobias, C. R., Song, B., Weston, N., Banta, G. T., and
Rivera-Monroy, V. H.: The importance of dissimilatory nitrate reduction to
ammonium (DNRA) in the nitrogen cycle of coastal ecosystems, Oceanography,
26, 124–131, https://doi.org/10.5670/oceanog.2013.54, 2013.
Gidhagen, L.: Coastal upwelling in the Baltic Sea. Satellite and in situ
measurements of sea surface temperatures indicating coastal upwelling,
Estuar. Coast. Shelf S., 24, 449–462,
https://doi.org/10.1016/0272-7714(87)90127-2, 1987.
Grasshoff, K., Kremling, K., and Ehrhardt, M.: Methods of Seawater Analysis,
Wiley-VCH, Weinheim/Deerfield Beach, Florida, 600 pp., 1999.
Griffiths, J. R., Kadin, M., Nascimento, F. J. A., Tamelander, T.,
Törnroos, A., Bonaglia, S., Bonsdorff, E., Brüchert, V.,
Gårdmark, A., Järnström, M., Kotta, J., Lindegren, M.,
Nordström, M. C., Norkko, A., Olsson, J., Weigel, B., Žydelis, R.,
Blenckner, T., Niiranen, S., and Winder, M.: The importance of
benthic-pelagic coupling formarine ecosystem functioning in a changing
world, Glob. Change Biol., 23, 2179–2196,
https://doi.org/10.1111/gcb.13642, 2017.
Gustafsson, B. G., Schenk, F., Blenckner, T., Eilola, K., Meier, H. E. M.,
Müller-Karulis, B., Neumann, T., Ruoho-Airola, T., Savchuk, O. P., and
Zorita, E.: Reconstructing the development of Baltic Sea eutrophication
1850–2006, Ambio, 41, 534–548,
https://doi.org/10.1007/s13280-012-0318-x, 2012.
Halpern, B. S., Walbridge, S., Selkoe, K. A., Kappel, C. V., Micheli, F.,
D'Agrosa, C., Bruno, J. F., Casey, K. S., Ebert, C., Fox, H. E., Fujita, R.,
Heinemann, D., Lenihan, H. S., Madin, E. M. P., Perry, M. T., Selig, E. R.,
Spalding, M., Steneck, R., and Watson, R.: A global map of human impact on
marine ecosystems, Science, 319, 948–952,
https://doi.org/10.1126/science.1149345, 2008.
Hansson, M., Viktorsson, L., and Andersson, L.: Oxygen survey in the Baltic
Sea 2018 – Extent of anoxia and hypoxia, 1960–2018, SMHI, Report
Oceanography No 65, 11 pp., 2019.
Hellemann, D., Tallberg, P., Bartl, B., Voss, M., and Hietanen, S.:
Denitrification in an oligotrophic estuary: a delayed sink for rivering
nitrate, Mar. Ecol. Prog. Ser., 583, 63–80,
https://doi.org/10.3354/meps12359, 2017.
Hermans, M., Lenstra, W. K., van Helmond, N. A. G. M., Behrends, T., Egger,
M., Séguret, M. J., Gustafsson, E., Gustafsson, B. G., and Slomp, C. P.:
Impact of natural re-oxygenation on the sediment dynamics of manganese, iron
and phosphorus in a euxinic Baltic Sea basin, Geochim. Cosmochim. Ac., 246,
174–196, https://doi.org/10.1016/j.gca.2018.11.033, 2019a.
Hermans, M., Lenstra, W. K., Hidalgo-Martinez, S., van Helmond, N. A. G. M.,
Witbaard, R., Meysman, F., Gonzalez, S., and Slomp, C. P.: Abundance and
Biogeochemical Impact of Cable Bacteria in Baltic Sea Sediments, Environ.
Sci. Technol., 53, 7494–7503, https://doi.org/10.1021/acs.est.9b01665,
2019b.
Hietanen, S., Laine, A. O., and Lukkari, K.,: The complex effects of the
invasive polychaetes Marenzelleria spp. on benthic nutrient dynamics, J. Exp. Mar. Biol.
Ecol., 352, 89–102, https://doi.org/10.1016/j.jembe.2007.07.018, 2007.
Hill, C. and Wallström, K.: Stockholm Archipelago, in: Ecology of
Baltic Coastal Waters (Ecological Studies 197), edited by: Schiewer, U.,
Springer-Verlag, Berlin, Heidelberg, Germany, 309–334, 2008.
Jackson, J. B. C., Kirby, M. X., Berger, W. H., Bjorndal, K. A., Botsford,
L. V., Bourque, B. J., Bradbury, R. H., Cooke, R., Erlandson, J., Estes, J.
A., Hughes, T. P., Kidwell, S., Lange, C. B., Lenihan, H. S., Pandolfi, J.
M., Peterson, C. H., Steneck, R. S., Tegner, M. J., and Warner, R. R.:
Historical overfishing and the recent collapse of coastal ecosystems,
Science, 293, 629–638, https://doi.org/10.1126/science.1059199, 2001.
Jäntti, H. and Hietanen, S.: The effects of hypoxia on sediment
nitrogen cycling in the Baltic Sea, Ambio, 41, 161–169,
https://doi.org/10.1007/s13280-011-0233-6, 2012.
Jäntti, H., Stange, F., Leskinen, E., and Hietanen, S.: Seasonal
variation in nitrification and nitrate-reduction pathways in coastal
sediments in the Gulf of Finland, Baltic Sea, Aquat. Microb. Ecol., 63,
171–181, https://doi.org/10.3354/ame01492, 2011.
Jensen, H. S., Mortensen, P. B., Andersen, F. O., Rasmussen, E., and Jensen,
A.: Phosphorus cycling in a coastal marine sediment, Aarhus Bay, Denmark,
Limnol. Oceanogr., 40, 908–917,
https://doi.org/10.4319/lo.1995.40.5.0908, 1995.
Johansson, L. and Wallström, K.: Urban impact in the history of water
quality in the Stockholm archipelago, Ambio, 30, 277–281,
https://doi.org/10.1579/0044-7447-30.4.277, 2001.
Jonsson, P., Carman, R., and Wulff, F.: Laminated Sediments in the Baltic: A
Tool for Evaluating Nutrient Mass Balances, Ambio, 19, 152–158, 1990.
Josefson, A. and Rasmussen, B.: Nutrient retention by benthic macrofaunal
biomass of Danish estuaries: Importance of nutrient load and residence time,
Estuar. Coast. Shelf Sci., 50, 205–216,
https://doi.org/10.1006/ecss.1999.0562, 2000.
Karlsson, O. M., Jonsson, P. O., Lindgren, D., Malmaeus, J. M., and Stehn,
A.: Indications of recovery from hypoxia in the inner Stockholm archipelago,
Ambio, 39, 486–495, https://doi.org/10.1007/s13280-010-0079-3, 2010.
Karlsson, O. M., Bryhn, A. C., Håkanson, L., Hållén, J.,
Jonsson, P., Malmaeus, J. M., and Rydin, E.: On the role of sedimentological
processes controlling phosphorus burial in the coastal zone of the Baltic
Sea, Limnol. Oceanogr., 64, 1828–1831, https://doi.org/10.1002/lno.11194,
2019.
Kemp, W. M., Testa, J. M., Conley, D. J., Gilbert, D., and Hagy, J. D.: Temporal responses of coastal hypoxia to nutrient loading and physical controls, Biogeosciences, 6, 2985–3008, https://doi.org/10.5194/bg-6-2985-2009, 2009.
Kessler, A. J., Roberts, K. L., Bissett, A., and Cook, P. L.: Biogeochemical
controls on the relative importance of denitrification and dissimilatory
nitrate reduction to ammonium in estuaries, Global Biogeochem. Cy., 32,
1045–1057, https://doi.org/10.1029/2018GB005908, 2018.
Kraal, P., Dijkstra, N., Behrends, T., and Slomp, C. P.: Phosphorus burial
in sediments of the sulfidic deep Black Sea: Key roles for adsorption by
calcium carbonate and apatite authigenesis, Geochim. Cosmochim. Ac., 204,
140–158, https://doi.org/10.1016/j.gca.2017.01.042, 2017.
Kraft, B., Tegetmeyer, H. E., Sharma, R., Klotz, M. G., Ferdelman, T. G.,
Hettich, R. L., Geelhoed, J. S., and Strous, M.: The environmental controls
that govern the end product of bacterial nitrate respiration, Science, 345,
676–679, https://doi.org/10.1126/science.1254070, 2014.
Krause-Jensen, D. and Duarte, C. M.: Substantial role of macroalgae in
marine carbon sequestration, Nat. Geosci., 9, 737–742,
https://doi.org/10.1038/ngeo2790, 2016.
Laverock, B., Gilbert, J., Tait, K., Osborn, A. M., and Widdicombe, S.:
Bioturbation: impact on the marine nitrogen cycle, Biochem. Soc. Trans., 39,
315–320, https://doi.org/10.1042/BST0390315, 2011.
Lenstra, W. K., Egger, M., van Helmond, N. A. G. M., Kritzberg, E., Conley, D. J., and Slomp, C. P.: Large variations in iron input to an oligotrophic Baltic Sea estuary: impact on sedimentary phosphorus burial, Biogeosciences, 15, 6979–6996, https://doi.org/10.5194/bg-15-6979-2018, 2018.
Lindh, G.: Miljörapport 2013, Stockholm Vatten VA AB, Stockholm Vatten, 87 pp.,
2013.
Lukkari, K., Leivuori, M., and Kotilainen, A.: The chemical character and
behaviour of phosphorus in poorly oxygenated sediments from open sea to
organic-rich inner bay in the Baltic Sea, Biogeochemistry, 96, 25–48,
https://doi.org/10.1007/s10533-009-9343-7, 2009.
McGlathery, K. J., Sundbäck, K., and Anderson, I. C.: Eutrophication in
shallow coastal bays and lagoons: The role of plants in the coastal filter,
Mar. Ecol. Prog. Ser., 348, 1–18, https://doi.org/10.3354/meps07132, 2007.
Mort, H. P., Slomp C. P., Gustafsson B. G., and Andersen, T. J.: Phosphorus
recycling and burial in Baltic Sea sediments with contrasting redox
conditions, Geochim. Cosmochim. Ac., 74, 1350–1362,
https://doi.org/10.1016/j.gca.2009.11.016, 2010.
Nembrini, G. P., Capobianco, J. A., Viel, M., and Williams, A. F.: A
Mössbauer and chemical study of the formation of vivianite in sediments
of Lago Maggiore (Italy), Geochim. Cosmochim. Ac., 47, 1459–1464,
https://doi.org/10.1016/0016-7037(83)90304-6, 1983.
Nielsen, L. P.: Denitrification in sediment determined from nitrogen isotope
pairing, FEMS Microbiol. Ecol., 9, 357–361,
https://doi.org/10.1111/j.1574-6968.1992.tb04828.x, 1992.
Ning, W., Ghosh, A., Jilbert, T., Slomp, C. P., Khan, M., Nyberg, J.,
Conley, D. J., and Filipsson, H. L.: Evolving coastal character of a Baltic
Sea inlet during the Holocene shoreline regression: impact on coastal zone
hypoxia, J. Paleolimnol., 55, 319–338,
https://doi.org/10.1007/s10933-016-9882-6, 2016.
Nixon, S. W., Ammerman, J. W., Atkinson, L. P., Berounsky, V. M., Billen,
G., Boicourt, W. C., Boynton, W. R., Church T. M., Ditoro D. M., Elmgren,
R., Garber J. H., Giblin, A. E., Jahnke, R. A., Owens N. J. P., Pilson M. E.
Q., and Seitzinger, S. P.: The fate of nitrogen and phosphorus at the land
sea margin of the North Atlantic Ocean, Biogeochemistry, 35, 141–180,
https://doi.org/10.1007/BF02179826, 1996.
Nizzoli, D., Carraro, E., Nigro, V., and Viaroli, P.: Effect of organic
enrichment and thermal regime on denitrification and dissimilatory nitrate
reduction to ammonium (DNRA) in hypolimnetic sediments of two lowland lakes,
Water Res., 44, 2715–2724, https://doi.org/10.1016/j.watres.2010.02.002,
2010.
Norkko, J., Reed, D. C., Timmermann, K., Norkko, A., Gustafsson, B. G.,
Bonsdorff, E., Slomp, C. P., Carstensen, J., and Conley, D. J.: A welcome
can of worms?, Hypoxia mitigation by an invasive species, Glob. Change Biol.
18, 422–434, https://doi.org/10.1111/j.1365-2486.2011.02513.x, 2012.
Paerl, H. W. and Otten, T. G.: Harmful cyanobacterial blooms: causes,
consequences, and controls, Microb. Ecol., 65, 995–1010,
https://doi.org/10.1007/s00248-012-0159-y, 2013.
Pelegri, S. P. and Blackburn, T. H.: Effect of bioturbation by Nereis sp.,
Mya arenaria and Cerastoderma sp. on nitrification and denitrification in
estuarine sediments, Ophelia, 42, 289–299,
https://doi.org/10.1080/00785326.1995.10431509, 1995.
Piña-Ochoa, E. and Álvarez-Cobelas, M.: Denitrification in aquatic
environments: A cross-system analysis, Biogeochemistry, 81, 111–130,
https://doi.org/10.1007/s10533-006-9033-7, 2006.
Poulton, S. W. and Canfield, D. E.: Development of a sequential extraction
procedure for iron: Implications for iron partitioning in continentally
derived particulates, Chem. Geol., 214, 209–221,
https://doi.org/10.1016/j.chemgeo.2004.09.003, 2005.
Rabalais, N. N., Turner, R. E., Diaz, R. J., and Justić, D.: Global
change and eutrophication of coastal waters, ICES J. Mar. Sci., 66,
1528–1537, https://doi.org/10.1093/icesjms/fsp047, 2009.
Rabalais, N. N., Díaz, R. J., Levin, L. A., Turner, R. E., Gilbert, D., and Zhang, J.: Dynamics and distribution of natural and human-caused hypoxia, Biogeosciences, 7, 585–619, https://doi.org/10.5194/bg-7-585-2010, 2010.
Reed, D. C., Slomp, C. P., and Gustafsson, B. G.: Sedimentary phosphorus
dynamics and the evolution of bottom-water hypoxia: A coupled
benthic–pelagic model of a coastal system, Limnol. Oceanogr., 56,
1075–1092, https://doi.org/10.4319/lo.2011.56.3.1075, 2011.
Risgaard-Petersen, N., Revsbech, N. P., and Rysgaard, S.: Combined
microdiffusion-hypobromite oxidation method for determining nitrogen-15
isotope in ammonium, Soil Sci. Soc. Am. J., 59, 1077–1080,
https://doi.org/10.2136/sssaj1995.03615995005900040018x, 1995.
Risgaard-Petersen, N., Nielsen, L. P., Rysgaard, S., Dalsgaard, T., and
Meyer, R. L.: Application of the isotope pairing technique in sediments
where anammox and denitrification coexist, Limn. Oceanog.-Meth., 1, 63–73,
https://doi.org/10.4319/lom.2003.1.63, 2003.
Robertson, E. K., Bartoli, M., Brüchert, V., Dalsgaard, T., Hall, P. O.
J., Hellemann, D., Hietanen, S., Zilius, M., and Conley, D. J.: Application
of the isotope pairing technique in sediments: use, challenges and new
directions, Limnol. Oceanogr.-Meth., 17, 112–136,
https://doi.org/10.1002/lom3.10303, 2019.
Ruttenberg, K. C.: Development of a sequential extraction method for
different forms of phosphorus in marine sediments, Limnol. Oceanogr., 37,
1460–1482, https://doi.org/10.4319/lo.1992.37.7.1460, 1992.
Ruttenberg, K. C. and Berner, R.A.: Authigenic apatite formation and burial
in sediments from non-upwelling, continental margin environments, Geochim. Cosmochim. Ac., 57, 991–1007,
https://doi.org/10.1016/0016-7037(93)90035-U, 1993.
Rydin, E. and Kumblad, L.: Capturing past eutrophication in coastal
sediments – Towards water-quality goals, Estuar. Coast. Shelf Sci., 221,
184–188, https://doi.org/10.1016/j.ecss.2019.02.046, 2019.
Rydin, E., Malmaeus, M., Karlsson, M., and Jonsson, P.: Phosphorus release
from coastal Baltic Sea sediments as estimated from sediment profiles,
Estuar. Coast Shelf Sci., 92, 111–117,
https://doi.org/10.1016/j.ecss.2010.12.020, 2011.
Savchuk, O. P.: Resolving the Baltic Sea into seven subbasins: N and P
budgets for 1991–1999, J. Mar. Syst., 56, 1–15,
https://doi.org/10.1016/j.jmarsys.2004.08.005, 2005.
Schnetger, B. and Lehners, C.: Determination of nitrate plus nitrite in
small volume marine water samples using vanadium (III) chloride as a
reduction agent, Mar. Chem., 160, 91–98,
https://doi.org/10.1016/j.marchem.2014.01.010, 2014.
Schulz, H. D.: Quantification of Early Diagenesis: Dissolved Constituents in
Pore Water and Signals in the Solid Phase, edited by: Schulz, H. D. and
Zabel, M., 2nd Edn., Springer-Verlag, Berlin,
Heidelberg, Germany, Mar. Chem., 73–124, 2006.
Seitzinger, S.: Denitrification in freshwater and coastal marine ecosystems:
Ecological and geochemical significance, Limnol. Oceanogr., 33, 702–724, https://doi.org/10.4319/lo.1988.33.4part2.0702, 1988.
Seitzinger, S.: Denitrification in aquatic sediments, in: Denitrification in
Soil and Sediment, edited by: Revsbech, N. P., Sørensen, J., Plenum
Press, New York, USA, 301–322, 1990.
Seitzinger, S., Harrison, J. A., Böhlke, J. K., Bouwman, A. F.,
Lowrance, R., Peterson, B., Tobias, C., and van Drecht, G.: Denitrification
across landscapes and waterscapes: a synthesis, Ecol. Appl., 6,
2064–2090, https://doi.org/10.1890/1051-0761(2006)016[2064:DALAWA]2.0.CO;2,
2006.
Silvennoinen, H., Hietanen, S., Liikanen, A., Stange, C. F., Russow, R.,
Kuparinen, J., and Martikainen, P. J.: Denitrification in the river estuaries
of the northern Baltic Sea, Ambio, 134–140,
https://doi.org/10.1579/0044-7447(2007)36[134:DITREO]2.0.CO;2, 2007.
Slomp, C. P.: Phosphorus cycling in the estuarine and coastal zones:
Sources, sinks, and Transformations, in: Treatise on estuarine and coastal
science, Vol. 5, edited by: Wolanski, E., McLusky, D. S., Academic Press,
Waltham, 201–229, 2011.
Slomp, C. P., Van der Gaast, S., and Van Raaphorst, W.: Phosphorus binding
by poorly crystalline iron oxides in North Sea sediments, Mar. Chem., 52,
55–73, https://doi.org/10.1016/0304-4203(95)00078-X, 1996.
Slomp, C. P., Mort, H. P., Jilbert, T., Reed, D. C., Gustafsson, B. G., and
Wolthers, M.: Coupled dynamics of iron and phosphorus in sediments of an
oligotrophic coastal basin and the impact of anaerobic oxidation of methane,
PLoS ONE, 8, e62386, https://doi.org/10.1371/journal.pone.0062386, 2013.
SMHI: Water chemistry data 1968–2017, Swedish Meteorological and
Hydrological Institute, available at: http://www.smhi.se/klimatdata/oceanografi/havsmiljodata/marina-miljoovervakningsdata,
or on request from shark@smhi.se, last access: 10 April 2019.
Smith, V. H.: Eutrophication of freshwater and coastal marine ecosystems a
global problem, Environ. Sci. Pollut. R., 10, 126–139,
https://doi.org/10.1065/espr2002.12.142, 2003.
Soetaert, K. and Herman, P. M. J.: A practical guide to ecological
modelling: using R as a simulation platform, Springer Science & Business
Media, 372 pp., 2009.
Song, G. D., Liu, S. M., Marchant, H., Kuypers, M. M. M., and Lavik, G.: Anammox, denitrification and dissimilatory nitrate reduction to ammonium in the East China Sea sediment, Biogeosciences, 10, 6851–6864, https://doi.org/10.5194/bg-10-6851-2013, 2013.
Song, G. D., Liu, S. M., Kuypers, M. M. M., and Lavik, G.: Application of
the isotope pairing technique in sediments where anammox, denitrification,
and dissimilatory nitrate reduction to ammonium coexist, Limnol.
Oceanogr.-Meth, 14, 801–815, https://doi.org/10.1002/lom3.10127, 2016.
Stigebrandt, A., Liljebladh, B., de Brabandere, L., Forth, M., Granmo,
Å., Hall, P., Hammar, J., Hansson, D., Kononets, M., Magnusson, M.,
Norén, F., Rahm, L., Treusch, A. H., and Viktorsson, L.: An experiment
with forced oxygenation of the deepwater of the anoxic by Fjord, Western
Sweden, Ambio, 44, 42–54, https://doi.org/10.1007/s13280-014-0524-9, 2015.
Strickland, J. D. H. and Parsons, T. R.: A Practical Handbook of Seawater
Analysis, Fisheries Research Board of Canada, Ottawa, 55, 167,
https://doi.org/10.1002/iroh.19700550118, 1972.
Sulu-Gambari, F., Hagens, M., Behrends, T., Seitaj, D., Meysman, F. J.,
Middelburg, J., and Slomp, C. P.: Phosphorus cycling and burial in sediments
of a seasonally hypoxic marine basin, Estuar. Coast., 41, 921–939,
https://doi.org/10.1007/s12237-017-0324-0, 2018.
Thamdrup, B.: New Pathways and processes in the global nitrogen cycle, Annu.
Rev. Ecol. Evol. S., 43, 407–428,
https://doi.org/10.1146/annurev-ecolsys-102710-145048, 2012.
Turner, R. E., Rabalais, N. N., and Justic, D.: Gulf of Mexico hypoxia:
Alternate states and a legacy, Environ. Sci. Technol., 42, 2323–2327,
https://doi.org/10.1021/es071617k, 2008.
Van Cappellen, P. and Ingall, E. D.: Benthic phosphorus regeneration, net
primary production, and ocean anoxia: a model of the coupled marine
biogeochemical cycles of carbon and phosphorus, Paleoceanography, 9,
677–692, https://doi.org/10.1029/94PA01455, 1994.
Van den Berg, L. J., Jones, L., Sheppard, L. J., Smart, S. M., Bobbink, R.,
Dise, N. B., and Ashmore, M. R.: Evidence for differential effects of
reduced and oxidised nitrogen deposition on vegetation independent of
nitrogen load, Environ. Pollut., 208, 890–897,
https://doi.org/10.1016/j.envpol.2015.09.017, 2016.
Van Helmond, N. A. G. M., Jilbert, T., and Slomp, C. P.: Hypoxia in the
Holocene Baltic Sea: Comparing modern versus past intervals using
sedimentary trace metals, Chem. Geol., 493, 478–490,
https://doi.org/10.1016/j.chemgeo.2018.06.028, 2018.
Van Helmond, N. A. G. M., Lougheed, B. C., Vollebregt, A., Peterse, F.,
Fontorbe, G., Conley, D. J., and Slomp, C. P.: Recovery from multi-millennial
natural coastal hypoxia in the Baltic Sea (Stockholm Archipelago) terminated
by modern human activity, Limnol. Oceanogr., in review, 2020.
Voss, M., Baker, A., Bange, H. W., Conley, D., Cornell, S., Deutsch, B.,
Engel, A., Ganeshram, R., Garnier, J., Heiskanen, A. S., Jickells, T.,
Lancelot, C., Mcquatters-Gollop, A., Middelburg, J., Schiedek, D., Slomp, C.
P., and Conley, D. P.: Nitrogen processes in coastal and marine ecosystems,
in: The European Nitrogen Assessment, edited by: Sutton, M. A., Howard, C.
M., Erisman, J. W., Billen, G., Bleeker, A., Grennfelt, P., van Grinsven,
H., Grizzetti, B., Cambridge University Press, New York, USA, 147–176,
2011.
Walve, J., Sandberg, M., Larsson, U., and Lännergren, C.: A Baltic Sea estuary as a phosphorus source and sink after drastic load reduction: seasonal and long-term mass balances for the Stockholm inner archipelago for 1968–2015, Biogeosciences, 15, 3003–3025, https://doi.org/10.5194/bg-15-3003-2018, 2018.
Short summary
We studied the removal of phosphorus (P) and nitrogen (N) in the eutrophic Stockholm archipelago (SA). High sedimentation rates and sediment P contents lead to high P burial. Benthic denitrification is the primary nitrate-reducing pathway. Together, these mechanisms limit P and N transport to the open Baltic Sea. We expect that further nutrient load reduction will contribute to recovery of the SA from low-oxygen conditions and that the sediments will continue to remove part of the P and N loads.
We studied the removal of phosphorus (P) and nitrogen (N) in the eutrophic Stockholm archipelago...
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