Articles | Volume 10, issue 11
https://doi.org/10.5194/bg-10-7449-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-10-7449-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
20 Nov 2013
Research article |
| 20 Nov 2013
Inter-annual variation of chlorophyll in the northern South China Sea observed at the SEATS Station and its asymmetric responses to climate oscillation
K.-K. Liu
Institute of Hydrological and Oceanic Sciences, National Central University, Chungli, Taiwan
L.-W. Wang
Institute of Hydrological and Oceanic Sciences, National Central University, Chungli, Taiwan
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
C.-M. Tseng
Institute of Oceanography, National Taiwan University, Taipei, Taiwan
Y. Yang
Taiwan Ocean Research Institute, National Applied Research Laboratories, Kaohsiung, Taiwan
C.-H. Sui
Department of Atmospheric Science, National Taiwan University, Taipei, Taiwan
L. Oey
Institute of Hydrological and Oceanic Sciences, National Central University, Chungli, Taiwan
K.-Y. Tseng
Institute of Hydrological and Oceanic Sciences, National Central University, Chungli, Taiwan
S.-M. Huang
Institute of Hydrological and Oceanic Sciences, National Central University, Chungli, Taiwan
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Ocean Alkalinity Enhancement boosts oceanic CO₂ absorption, offering a climate solution. Using a regional model, we examined OAE in the North Sea, revealing that shallow coastal areas achieve higher CO₂ uptake than offshore, where alkalinity is more susceptible to deep-ocean loss. Long-term carbon storage is limited, and pH shifts vary by location. Our findings guide OAE deployment to optimize carbon removal while minimizing ecological effects, supporting global climate mitigation efforts.
Jessica L. Oberlander, Mackenzie E. Burke, Cat A. London, and Hugh L. MacIntyre
Biogeosciences, 22, 499–512, https://doi.org/10.5194/bg-22-499-2025, https://doi.org/10.5194/bg-22-499-2025, 2025
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Ocean alkalinity enhancement (OAE) is a promising negative emission technology that results in the net sequestration of atmospheric carbon. In this paper, we assess the potential impact of OAE on phytoplankton through an analysis of prior studies and the effects of simulated OAE on photosynthetic competence. Our findings suggest that there may be little if any significant impact on most phytoplankton studied to date if OAE is conducted in well-flushed, nearshore environments.
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, and Ulf Riebesell
Biogeosciences, 21, 5707–5724, https://doi.org/10.5194/bg-21-5707-2024, https://doi.org/10.5194/bg-21-5707-2024, 2024
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This study exposed a natural community to two non-CO2-equilibrated ocean alkalinity enhancement (OAE) deployments using different minerals. Adding alkalinity in this manner decreases dissolved CO2, essential for photosynthesis. While photosynthesis was not suppressed, bloom formation was mildly delayed, potentially impacting marine food webs. The study emphasizes the need for further research on OAE without prior equilibration and on its ecological implications.
Riss M. Kell, Rebecca J. Chmiel, Deepa Rao, Dawn M. Moran, Matthew R. McIlvin, Tristan J. Horner, Nicole L. Schanke, Ichiko Sugiyama, Robert B. Dunbar, Giacomo R. DiTullio, and Mak A. Saito
Biogeosciences, 21, 5685–5706, https://doi.org/10.5194/bg-21-5685-2024, https://doi.org/10.5194/bg-21-5685-2024, 2024
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Despite interest in modeling the biogeochemical uptake and cycling of the trace metal zinc (Zn), measurements of Zn uptake in natural marine phytoplankton communities have not been conducted previously. To fill this gap, we employed a stable isotope uptake rate measurement method to quantify Zn uptake into natural phytoplankton assemblages within the Southern Ocean. Zn demand was high and rapid enough to depress the inventory of Zn available to phytoplankton on seasonal timescales.
Luisa Chiara Meiritz, Tim Rixen, Anja Karin van der Plas, Tarron Lamont, and Niko Lahajnar
Biogeosciences, 21, 5261–5276, https://doi.org/10.5194/bg-21-5261-2024, https://doi.org/10.5194/bg-21-5261-2024, 2024
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Moored and drifting sediment trap experiments in the northern (nBUS) and southern (sBUS) Benguela Upwelling System showed that active carbon fluxes by vertically migrating zooplankton were about 3 times higher in the sBUS than in the nBUS. Despite these large variabilities, the mean passive particulate organic carbon (POC) fluxes were almost equal in the two subsystems. The more intense near-bottom oxygen minimum layer seems to lead to higher POC fluxes and accumulation rates in the nBUS.
Michael R. Roman, Andrew H. Altieri, Denise Breitburg, Erica M. Ferrer, Natalya D. Gallo, Shin-ichi Ito, Karin Limburg, Kenneth Rose, Moriaki Yasuhara, and Lisa A. Levin
Biogeosciences, 21, 4975–5004, https://doi.org/10.5194/bg-21-4975-2024, https://doi.org/10.5194/bg-21-4975-2024, 2024
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Oxygen-depleted ocean waters have increased worldwide. In order to improve our understanding of the impacts of this oxygen loss on marine life it is essential that we develop reliable indicators that track the negative impacts of low oxygen. We review various indicators of low-oxygen stress for marine animals including their use, research needs, and application to confront the challenges of ocean oxygen loss.
Charlotte Eich, Mathijs van Manen, J. Scott P. McCain, Loay J. Jabre, Willem H. van de Poll, Jinyoung Jung, Sven B. E. H. Pont, Hung-An Tian, Indah Ardiningsih, Gert-Jan Reichart, Erin M. Bertrand, Corina P. D. Brussaard, and Rob Middag
Biogeosciences, 21, 4637–4663, https://doi.org/10.5194/bg-21-4637-2024, https://doi.org/10.5194/bg-21-4637-2024, 2024
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Phytoplankton growth in the Southern Ocean (SO) is often limited by low iron (Fe) concentrations. Sea surface warming impacts Fe availability and can affect phytoplankton growth. We used shipboard Fe clean incubations to test how changes in Fe and temperature affect SO phytoplankton. Their abundances usually increased with Fe addition and temperature increase, with Fe being the major factor. These findings imply potential shifts in ecosystem structure, impacting food webs and elemental cycling.
Miriam Tivig, David P. Keller, and Andreas Oschlies
Biogeosciences, 21, 4469–4493, https://doi.org/10.5194/bg-21-4469-2024, https://doi.org/10.5194/bg-21-4469-2024, 2024
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Marine biological production is highly dependent on the availability of nitrogen and phosphorus. Rivers are the main source of phosphorus to the oceans but poorly represented in global model oceans. We include dissolved nitrogen and phosphorus from river export in a global model ocean and find that the addition of riverine phosphorus affects marine biology on millennial timescales more than riverine nitrogen alone. Globally, riverine phosphorus input increases primary production rates.
Esdoorn Willcox, Marcos Lemes, Thomas Juul-Pedersen, Mikael Kristian Sejr, Johnna Marchiano Holding, and Søren Rysgaard
Biogeosciences, 21, 4037–4050, https://doi.org/10.5194/bg-21-4037-2024, https://doi.org/10.5194/bg-21-4037-2024, 2024
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In this work, we measured the chemistry of seawater from samples obtained from different depths and locations off the east coast of the Northeast Greenland National Park to determine what is influencing concentrations of dissolved CO2. Historically, the region has always been thought to take up CO2 from the atmosphere, but we show that it is possible for the region to become a source in late summer. We discuss the variables that may be related to such changes.
Vlad A. Macovei, Louise C. V. Rewrie, Rüdiger Röttgers, and Yoana G. Voynova
EGUsphere, https://doi.org/10.5194/egusphere-2024-2643, https://doi.org/10.5194/egusphere-2024-2643, 2024
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A commercial vessel equipped with scientific instruments regularly travelled between two large macro-tidal estuaries. We found that biogeochemical variability in the outer estuaries is driven by the 14-day spring-neap tidal cycle, with strong effects on dissolved inorganic and organic carbon concentrations and distribution. Since this land-sea interface effect increases the strength of the carbon source to the atmosphere by 74 % during spring tide, it should be accounted for in regional models.
Lennart Thomas Bach, Aaron James Ferderer, Julie LaRoche, and Kai Georg Schulz
Biogeosciences, 21, 3665–3676, https://doi.org/10.5194/bg-21-3665-2024, https://doi.org/10.5194/bg-21-3665-2024, 2024
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Ocean alkalinity enhancement (OAE) is an emerging marine CO2 removal method, but its environmental effects are insufficiently understood. The OAE Pelagic Impact Intercomparison Project (OAEPIIP) provides funding for a standardized and globally replicated microcosm experiment to study the effects of OAE on plankton communities. Here, we provide a detailed manual for the OAEPIIP experiment. We expect OAEPIIP to help build scientific consensus on the effects of OAE on plankton.
Marlena Szeligowska, Déborah Benkort, Anna Przyborska, Mateusz Moskalik, Bernabé Moreno, Emilia Trudnowska, and Katarzyna Błachowiak-Samołyk
Biogeosciences, 21, 3617–3639, https://doi.org/10.5194/bg-21-3617-2024, https://doi.org/10.5194/bg-21-3617-2024, 2024
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The European Arctic is experiencing rapid regional warming, causing glaciers that terminate in the sea to retreat onto land. Due to this process, the area of a well-studied fjord, Hornsund, has increased by around 100 km2 (40%) since 1976. Combining satellite and in situ data with a mathematical model, we estimated that, despite some negative consequences of glacial meltwater release, such emerging coastal waters could mitigate climate change by increasing carbon uptake and storage by sediments.
Mallory C. Ringham, Nathan Hirtle, Cody Shaw, Xi Lu, Julian Herndon, Brendan R. Carter, and Matthew D. Eisaman
Biogeosciences, 21, 3551–3570, https://doi.org/10.5194/bg-21-3551-2024, https://doi.org/10.5194/bg-21-3551-2024, 2024
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Ocean alkalinity enhancement leverages the large surface area and carbon storage capacity of the oceans to store atmospheric CO2 as dissolved bicarbonate. We monitored CO2 uptake in seawater treated with NaOH to establish operational boundaries for carbon removal experiments. Results show that CO2 equilibration occurred on the order of weeks to months, was consistent with values expected from equilibration calculations, and was limited by mineral precipitation at high pH and CaCO3 saturation.
Riel Carlo O. Ingeniero, Gesa Schulz, and Hermann W. Bange
Biogeosciences, 21, 3425–3440, https://doi.org/10.5194/bg-21-3425-2024, https://doi.org/10.5194/bg-21-3425-2024, 2024
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Our research is the first to measure dissolved NO concentrations in temperate estuarine waters, providing insights into its distribution under varying conditions and enhancing our understanding of its production processes. Dissolved NO was supersaturated in the Elbe Estuary, indicating that it is a source of atmospheric NO. The observed distribution of dissolved NO most likely resulted from nitrification.
Weiyi Tang, Jeff Talbott, Timothy Jones, and Bess B. Ward
Biogeosciences, 21, 3239–3250, https://doi.org/10.5194/bg-21-3239-2024, https://doi.org/10.5194/bg-21-3239-2024, 2024
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Wastewater treatment plants (WWTPs) are known to be hotspots of greenhouse gas emissions. However, the impact of WWTPs on the emission of the greenhouse gas N2O in downstream aquatic environments is less constrained. We found spatially and temporally variable but overall higher N2O concentrations and fluxes in waters downstream of WWTPs, pointing to the need for efficient N2O removal in addition to the treatment of nitrogen in WWTPs.
Daniel Müller, Bo Liu, Walter Geibert, Moritz Holtappels, Lasse Sander, Elda Miramontes, Heidi Taubner, Susann Henkel, Kai-Uwe Hinrichs, Denise Bethke, Ingrid Dohrmann, and Sabine Kasten
EGUsphere, https://doi.org/10.5194/egusphere-2024-1632, https://doi.org/10.5194/egusphere-2024-1632, 2024
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Coastal and shelf sediments are the most important sinks for organic carbon (OC) on Earth. We produced a new high-resolution sediment and pore-water dataset from the Helgoland Mud Area (HMA), North Sea, to determine, which depositional factors control the preservation of OC. The burial efficiency is highest in an area of high sedimentation and terrigenous OC. The HMA covers 0.09 % of the North Sea, but accounts for 0.76 % of its OC accumulation, highlighting the importance of the depocentre.
Deep S. Banerjee and Jozef Skakala
EGUsphere, https://doi.org/10.22541/essoar.171405637.76928549/v1, https://doi.org/10.22541/essoar.171405637.76928549/v1, 2024
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Nitrate is a crucial nutrient in oceans. Excess nutrients can trigger uncontrolled algae growth (eutrophication), damaging marine ecosystems. We used a machine learning tool to generate a skilled, gap-free, bi-decadal surface nitrate dataset from sparse observations. This dataset reveals areas on the North West European Shelf at risk of eutrophication, bi-decadal trends in coastal nitrate, and an impact of winter nitrate on spring phytoplankton blooms.
Amanda Y. L. Cheong, Kogila Vani Annammala, Ee Ling Yong, Yongli Zhou, Robert S. Nichols, and Patrick Martin
Biogeosciences, 21, 2955–2971, https://doi.org/10.5194/bg-21-2955-2024, https://doi.org/10.5194/bg-21-2955-2024, 2024
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We measured nutrients and dissolved organic matter for 1 year in a eutrophic tropical estuary to understand their sources and cycling. Our data show that the dissolved organic matter originates partly from land and partly from microbial processes in the water. Internal recycling is likely important for maintaining high nutrient concentrations, and we found that there is often excess nitrogen compared to silicon and phosphorus. Our data help to explain how eutrophication persists in this system.
Darren Pilcher, Jessica Cross, Natalie Monacci, Linquan Mu, Kelly Kearney, Albert Hermann, and Wei Cheng
EGUsphere, https://doi.org/10.5194/egusphere-2024-1096, https://doi.org/10.5194/egusphere-2024-1096, 2024
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The Bering Sea shelf is a highly productive marine ecosystem that is vulnerable to ocean acidification. We use a computational model to simulate the carbon cycle and acidification rates from 1970–2022. The results suggest that bottom water acidification rates are more than twice as great as surface rates. Bottom waters are also naturally more acidic, thus these waters will pass key thresholds known to negatively impact marine organisms, such as red king crab, much sooner than surface waters.
Aaron Ferderer, Kai G. Schulz, Ulf Riebesell, Kirralee G. Baker, Zanna Chase, and Lennart T. Bach
Biogeosciences, 21, 2777–2794, https://doi.org/10.5194/bg-21-2777-2024, https://doi.org/10.5194/bg-21-2777-2024, 2024
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Ocean alkalinity enhancement (OAE) is a promising method of atmospheric carbon removal; however, its ecological impacts remain largely unknown. We assessed the effects of simulated silicate- and calcium-based mineral OAE on diatom silicification. We found that increased silicate concentrations from silicate-based OAE increased diatom silicification. In contrast, the enhancement of alkalinity had no effect on community silicification and minimal effects on the silicification of different genera.
David González-Santana, María Segovia, Melchor González-Dávila, Librada Ramírez, Aridane G. González, Leonardo J. Pozzo-Pirotta, Veronica Arnone, Victor Vázquez, Ulf Riebesell, and J. Magdalena Santana-Casiano
Biogeosciences, 21, 2705–2715, https://doi.org/10.5194/bg-21-2705-2024, https://doi.org/10.5194/bg-21-2705-2024, 2024
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In a recent experiment off the coast of Gran Canaria (Spain), scientists explored a method called ocean alkalinization enhancement (OAE), where carbonate minerals were added to seawater. This process changed the levels of certain ions in the water, affecting its pH and buffering capacity. The researchers were particularly interested in how this could impact the levels of essential trace metals in the water.
Lucas Porz, Wenyan Zhang, Nils Christiansen, Jan Kossack, Ute Daewel, and Corinna Schrum
Biogeosciences, 21, 2547–2570, https://doi.org/10.5194/bg-21-2547-2024, https://doi.org/10.5194/bg-21-2547-2024, 2024
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Seafloor sediments store a large amount of carbon, helping to naturally regulate Earth's climate. If disturbed, some sediment particles can turn into CO2, but this effect is not well understood. Using computer simulations, we found that bottom-contacting fishing gears release about 1 million tons of CO2 per year in the North Sea, one of the most heavily fished regions globally. We show how protecting certain areas could reduce these emissions while also benefitting seafloor-living animals.
Jiaying A. Guo, Robert F. Strzepek, Kerrie M. Swadling, Ashley T. Townsend, and Lennart T. Bach
Biogeosciences, 21, 2335–2354, https://doi.org/10.5194/bg-21-2335-2024, https://doi.org/10.5194/bg-21-2335-2024, 2024
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Ocean alkalinity enhancement aims to increase atmospheric CO2 sequestration by adding alkaline materials to the ocean. We assessed the environmental effects of olivine and steel slag powder on coastal plankton. Overall, slag is more efficient than olivine in releasing total alkalinity and, thus, in its ability to sequester CO2. Slag also had less environmental effect on the enclosed plankton communities when considering its higher CO2 removal potential based on this 3-week experiment.
Giovanni Galli, Sarah Wakelin, James Harle, Jason Holt, and Yuri Artioli
Biogeosciences, 21, 2143–2158, https://doi.org/10.5194/bg-21-2143-2024, https://doi.org/10.5194/bg-21-2143-2024, 2024
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This work shows that, under a high-emission scenario, oxygen concentration in deep water of parts of the North Sea and Celtic Sea can become critically low (hypoxia) towards the end of this century. The extent and frequency of hypoxia depends on the intensity of climate change projected by different climate models. This is the result of a complex combination of factors like warming, increase in stratification, changes in the currents and changes in biological processes.
Sandy E. Tenorio and Laura Farías
Biogeosciences, 21, 2029–2050, https://doi.org/10.5194/bg-21-2029-2024, https://doi.org/10.5194/bg-21-2029-2024, 2024
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Time series studies show that CH4 is highly dynamic on the coastal ocean surface and planktonic communities are linked to CH4 accumulation, as found in coastal upwelling off Chile. We have identified the crucial role of picoplankton (> 3 µm) in CH4 recycling, especially with the addition of methylated substrates (trimethylamine and methylphosphonic acid) during upwelling and non-upwelling periods. These insights improve understanding of surface ocean CH4 recycling, aiding CH4 emission estimates.
Charlotte A. J. Williams, Tom Hull, Jan Kaiser, Claire Mahaffey, Naomi Greenwood, Matthew Toberman, and Matthew R. Palmer
Biogeosciences, 21, 1961–1971, https://doi.org/10.5194/bg-21-1961-2024, https://doi.org/10.5194/bg-21-1961-2024, 2024
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Oxygen (O2) is a key indicator of ocean health. The risk of O2 loss in the productive coastal/continental slope regions is increasing. Autonomous underwater vehicles equipped with O2 optodes provide lots of data but have problems resolving strong vertical O2 changes. Here we show how to overcome this and calculate how much O2 is supplied to the low-O2 bottom waters via mixing. Bursts in mixing supply nearly all of the O2 to bottom waters in autumn, stopping them reaching ecologically low levels.
Sabine Schmidt and Ibrahima Iris Diallo
Biogeosciences, 21, 1785–1800, https://doi.org/10.5194/bg-21-1785-2024, https://doi.org/10.5194/bg-21-1785-2024, 2024
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Along the French coast facing the Bay of Biscay, the large Gironde and Loire estuaries suffer from hypoxia. This prompted a study of the small Charente estuary located between them. This work reveals a minimum oxygen zone in the Charente estuary, which extends for about 25 km. Temperature is the main factor controlling the hypoxia. This calls for the monitoring of small turbid macrotidal estuaries that are vulnerable to hypoxia, a risk expected to increase with global warming.
Simone R. Alin, Jan A. Newton, Richard A. Feely, Samantha Siedlecki, and Dana Greeley
Biogeosciences, 21, 1639–1673, https://doi.org/10.5194/bg-21-1639-2024, https://doi.org/10.5194/bg-21-1639-2024, 2024
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We provide a new multi-stressor data product that allows us to characterize the seasonality of temperature, O2, and CO2 in the southern Salish Sea and delivers insights into the impacts of major marine heatwave and precipitation anomalies on regional ocean acidification and hypoxia. We also describe the present-day frequencies of temperature, O2, and ocean acidification conditions that cross thresholds of sensitive regional species that are economically or ecologically important.
Pamela Linford, Iván Pérez-Santos, Paulina Montero, Patricio A. Díaz, Claudia Aracena, Elías Pinilla, Facundo Barrera, Manuel Castillo, Aida Alvera-Azcárate, Mónica Alvarado, Gabriel Soto, Cécile Pujol, Camila Schwerter, Sara Arenas-Uribe, Pilar Navarro, Guido Mancilla-Gutiérrez, Robinson Altamirano, Javiera San Martín, and Camila Soto-Riquelme
Biogeosciences, 21, 1433–1459, https://doi.org/10.5194/bg-21-1433-2024, https://doi.org/10.5194/bg-21-1433-2024, 2024
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The Patagonian fjords comprise a world region where low-oxygen water and hypoxia conditions are observed. An in situ dataset was used to quantify the mechanism involved in the presence of these conditions in northern Patagonian fjords. Water mass analysis confirmed the contribution of Equatorial Subsurface Water in the advection of the low-oxygen water, and hypoxic conditions occurred when the community respiration rate exceeded the gross primary production.
Ting Wang, Buyun Du, Inke Forbrich, Jun Zhou, Joshua Polen, Elsie M. Sunderland, Prentiss H. Balcom, Celia Chen, and Daniel Obrist
Biogeosciences, 21, 1461–1476, https://doi.org/10.5194/bg-21-1461-2024, https://doi.org/10.5194/bg-21-1461-2024, 2024
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The strong seasonal increases of Hg in aboveground biomass during the growing season and the lack of changes observed after senescence in this salt marsh ecosystem suggest physiologically controlled Hg uptake pathways. The Hg sources found in marsh aboveground tissues originate from a mix of sources, unlike terrestrial ecosystems, where atmospheric GEM is the main source. Belowground plant tissues mostly take up Hg from soils. Overall, the salt marsh currently serves as a small net Hg sink.
Eleanor Simpson, Debby Ianson, Karen E. Kohfeld, Ana C. Franco, Paul A. Covert, Marty Davelaar, and Yves Perreault
Biogeosciences, 21, 1323–1353, https://doi.org/10.5194/bg-21-1323-2024, https://doi.org/10.5194/bg-21-1323-2024, 2024
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Shellfish aquaculture operates in nearshore areas where data on ocean acidification parameters are limited. We show daily and seasonal variability in pH and saturation states of calcium carbonate at nearshore aquaculture sites in British Columbia, Canada, and determine the contributing drivers of this variability. We find that nearshore locations have greater variability than open waters and that the uptake of carbon by phytoplankton is the major driver of pH and saturation state variability.
S. Alejandra Castillo Cieza, Rachel H. R. Stanley, Pierre Marrec, Diana N. Fontaine, E. Taylor Crockford, Dennis J. McGillicuddy Jr., Arshia Mehta, Susanne Menden-Deuer, Emily E. Peacock, Tatiana A. Rynearson, Zoe O. Sandwith, Weifeng Zhang, and Heidi M. Sosik
Biogeosciences, 21, 1235–1257, https://doi.org/10.5194/bg-21-1235-2024, https://doi.org/10.5194/bg-21-1235-2024, 2024
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The coastal ocean in the northeastern USA provides many services, including fisheries and habitats for threatened species. In summer 2019, a bloom occurred of a large unusual phytoplankton, the diatom Hemiaulus, with nitrogen-fixing symbionts. This led to vast changes in productivity and grazing rates in the ecosystem. This work shows that the emergence of one species can have profound effects on ecosystem function. Such changes may become more prevalent as the ocean warms due to climate change.
Claudine Hauri, Brita Irving, Sam Dupont, Rémi Pagés, Donna D. W. Hauser, and Seth L. Danielson
Biogeosciences, 21, 1135–1159, https://doi.org/10.5194/bg-21-1135-2024, https://doi.org/10.5194/bg-21-1135-2024, 2024
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Arctic marine ecosystems are highly susceptible to impacts of climate change and ocean acidification. We present pH and pCO2 time series (2016–2020) from the Chukchi Ecosystem Observatory and analyze the drivers of the current conditions to get a better understanding of how climate change and ocean acidification could affect the ecological niches of organisms.
William Hiles, Lucy C. Miller, Craig Smeaton, and William E. N. Austin
Biogeosciences, 21, 929–948, https://doi.org/10.5194/bg-21-929-2024, https://doi.org/10.5194/bg-21-929-2024, 2024
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Saltmarsh soils may help to limit the rate of climate change by storing carbon. To understand their impacts, they must be accurately mapped. We use drone data to estimate the size of three saltmarshes in NE Scotland. We find that drone imagery, combined with tidal data, can reliably inform our understanding of saltmarsh size. When compared with previous work using vegetation communities, we find that our most reliable new estimates of stored carbon are 15–20 % smaller than previously estimated.
De'Marcus Robinson, Anh L. D. Pham, David J. Yousavich, Felix Janssen, Frank Wenzhöfer, Eleanor C. Arrington, Kelsey M. Gosselin, Marco Sandoval-Belmar, Matthew Mar, David L. Valentine, Daniele Bianchi, and Tina Treude
Biogeosciences, 21, 773–788, https://doi.org/10.5194/bg-21-773-2024, https://doi.org/10.5194/bg-21-773-2024, 2024
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The present study suggests that high release of ferrous iron from the seafloor of the oxygen-deficient Santa Barabara Basin (California) supports surface primary productivity, creating positive feedback on seafloor iron release by enhancing low-oxygen conditions in the basin.
David J. Yousavich, De'Marcus Robinson, Xuefeng Peng, Sebastian J. E. Krause, Frank Wenzhöfer, Felix Janssen, Na Liu, Jonathan Tarn, Franklin Kinnaman, David L. Valentine, and Tina Treude
Biogeosciences, 21, 789–809, https://doi.org/10.5194/bg-21-789-2024, https://doi.org/10.5194/bg-21-789-2024, 2024
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Declining oxygen (O2) concentrations in coastal oceans can threaten people’s ways of life and food supplies. Here, we investigate how mats of bacteria that proliferate on the seafloor of the Santa Barbara Basin sustain and potentially worsen these O2 depletion events through their unique chemoautotrophic metabolism. Our study shows how changes in seafloor microbiology and geochemistry brought on by declining O2 concentrations can help these mats grow as well as how that growth affects the basin.
Krysten Rutherford, Katja Fennel, Lina Garcia Suarez, and Jasmin G. John
Biogeosciences, 21, 301–314, https://doi.org/10.5194/bg-21-301-2024, https://doi.org/10.5194/bg-21-301-2024, 2024
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We downscaled two mid-century (~2075) ocean model projections to a high-resolution regional ocean model of the northwest North Atlantic (NA) shelf. In one projection, the NA shelf break current practically disappears; in the other it remains almost unchanged. This leads to a wide range of possible future shelf properties. More accurate projections of coastal circulation features would narrow the range of possible outcomes of biogeochemical projections for shelf regions.
Lennart Thomas Bach
Biogeosciences, 21, 261–277, https://doi.org/10.5194/bg-21-261-2024, https://doi.org/10.5194/bg-21-261-2024, 2024
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Ocean alkalinity enhancement (OAE) is a widely considered marine carbon dioxide removal method. OAE aims to accelerate chemical rock weathering, which is a natural process that slowly sequesters atmospheric carbon dioxide. This study shows that the addition of anthropogenic alkalinity via OAE can reduce the natural release of alkalinity and, therefore, reduce the efficiency of OAE for climate mitigation. However, the additionality problem could be mitigated via a variety of activities.
Tsuneo Ono, Daisuke Muraoka, Masahiro Hayashi, Makiko Yorifuji, Akihiro Dazai, Shigeyuki Omoto, Takehiro Tanaka, Tomohiro Okamura, Goh Onitsuka, Kenji Sudo, Masahiko Fujii, Ryuji Hamanoue, and Masahide Wakita
Biogeosciences, 21, 177–199, https://doi.org/10.5194/bg-21-177-2024, https://doi.org/10.5194/bg-21-177-2024, 2024
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We carried out parallel year-round observations of pH and related parameters in five stations around the Japan coast. It was found that short-term acidified situations with Omega_ar less than 1.5 occurred at four of five stations. Most of such short-term acidified events were related to the short-term low salinity event, and the extent of short-term pH drawdown at high freshwater input was positively correlated with the nutrient concentration of the main rivers that flow into the coastal area.
K. Mareike Paul, Martijn Hermans, Sami A. Jokinen, Inda Brinkmann, Helena L. Filipsson, and Tom Jilbert
Biogeosciences, 20, 5003–5028, https://doi.org/10.5194/bg-20-5003-2023, https://doi.org/10.5194/bg-20-5003-2023, 2023
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Seawater naturally contains trace metals such as Mo and U, which accumulate under low oxygen conditions on the seafloor. Previous studies have used sediment Mo and U contents as an archive of changing oxygen concentrations in coastal waters. Here we show that in fjords the use of Mo and U for this purpose may be impaired by additional processes. Our findings have implications for the reliable use of Mo and U to reconstruct oxygen changes in fjords.
Hannah Sharpe, Michel Gosselin, Catherine Lalande, Alexandre Normandeau, Jean-Carlos Montero-Serrano, Khouloud Baccara, Daniel Bourgault, Owen Sherwood, and Audrey Limoges
Biogeosciences, 20, 4981–5001, https://doi.org/10.5194/bg-20-4981-2023, https://doi.org/10.5194/bg-20-4981-2023, 2023
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We studied the impact of submarine canyon processes within the Pointe-des-Monts system on biogenic matter export and phytoplankton assemblages. Using data from three oceanographic moorings, we show that the canyon experienced two low-amplitude sediment remobilization events in 2020–2021 that led to enhanced particle fluxes in the deep-water column layer > 2.6 km offshore. Sinking phytoplankton fluxes were lower near the canyon compared to background values from the lower St. Lawrence Estuary.
Dewi Langlet, Florian Mermillod-Blondin, Noémie Deldicq, Arthur Bauville, Gwendoline Duong, Lara Konecny, Mylène Hugoni, Lionel Denis, and Vincent M. P. Bouchet
Biogeosciences, 20, 4875–4891, https://doi.org/10.5194/bg-20-4875-2023, https://doi.org/10.5194/bg-20-4875-2023, 2023
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Benthic foraminifera are single-cell marine organisms which can move in the sediment column. They were previously reported to horizontally and vertically transport sediment particles, yet the impact of their motion on the dissolved fluxes remains unknown. Using microprofiling, we show here that foraminiferal burrow formation increases the oxygen penetration depth in the sediment, leading to a change in the structure of the prokaryotic community.
Masahiko Fujii, Ryuji Hamanoue, Lawrence Patrick Cases Bernardo, Tsuneo Ono, Akihiro Dazai, Shigeyuki Oomoto, Masahide Wakita, and Takehiro Tanaka
Biogeosciences, 20, 4527–4549, https://doi.org/10.5194/bg-20-4527-2023, https://doi.org/10.5194/bg-20-4527-2023, 2023
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This is the first study of the current and future impacts of climate change on Pacific oyster farming in Japan. Future coastal warming and acidification may affect oyster larvae as a result of longer exposure to lower-pH waters. A prolonged spawning period may harm oyster processing by shortening the shipping period and reducing oyster quality. To minimize impacts on Pacific oyster farming, in addition to mitigation measures, local adaptation measures may be required.
Cited articles
Cai, W. J., van Rensch, P., Cowan, T., and Hendon, H. H.: An asymmetry in the IOD and ENSO teleconnection pathway and its impact on Australian climate, J. Climate, 25, 6318–6329, https://doi.org/10.1175/jcli-d-11-00501.1, 2012.
Centurioni, L. R., Niiler, P. P., and Lee, D. K.: Observations of inflow of Philippine Sea surface water into the South China Sea through the Luzon Strait, J. Phys. Oceanogr., 34, 113–121, 2004.
Chang, Y. L. and Oey, L. Y.: The Philippines-Taiwan Oscillation: Monsoonlike interannual oscillation of the subtropical-tropical western North Pacific wind system and its impact on the Ocean, J. Climate, 25, 1597–1618, https://doi.org/10.1175/jcli-d-11-00158.1, 2012.
Chao, S. Y., Shaw, P. T., and Wu, S. Y.: Deep-Water Ventilation in the South China Sea, Deep-Sea Res. P.t I, 43, 445–466, 1996a.
Chao, S. Y., Shaw, P. T., and Wu, S. Y.: El Niño modulation of the South China Sea circulation, Prog. Oceanogr., 38, 51–93, 1996b.
Chen, C. C., Shiah, F. K., Chung, S. W., and Liu, K. K.: Winter phytoplankton blooms in the shallow mixed layer of the South China Sea enhanced by upwelling, J. Marine Syst., 59, 97–110, 2006.
Chen, C. S., Lai, Z. G., Beardsley, R. C., Xu, Q. C., Lin, H. C., and Viet, N. T.: Current separation and upwelling over the southeast shelf of Vietnam in the South China Sea, J. Geophys. Res.-Oceans, 117, C03033, https://doi.org/10.1029/2011jc007150, 2012a.
Chen, G. X., Gan, J. P., Xie, Q., Chu, X. Q., Wang, D. X., and Hou, Y. J.: Eddy heat and salt transports in the South China Sea and their seasonal modulations, J. Geophys. Res.-Oceans, 117, C05021, https://doi.org/10.1029/2011jc007724, 2012b.
Chen, Y. L. L., Chen, H. Y., Lin, II, Lee, M. A., and Chang, J.: Effects of cold eddy on Phytoplankton production and assemblages in Luzon Strait bordering the South China Sea, J. Oceanogr., 63, 671–683, https://doi.org/10.1007/s10872-007-0059-9, 2007.
Fang, G. H., Wang, Y. G., Wei, Z. X., Fang, Y., Qiao, F. L., and Hu, X. M.: Interocean circulation and heat and freshwater budgets of the South China Sea based on a numerical model, Dynamics of Atmospheres and Oceans, 47, 55–72, https://doi.org/10.1016/j.dynatmoce.2008.09.003, 2009.
Gong, G.-C., Liu, K.-K., Liu, C.-T., and Pai, S.-C.: Chemical hydrography of the South China Sea and a comparison with the West Philippine Sea, Terr. Atmos. Ocean Sci., 3, 587–602, 1992.
Gordon, A. L., Huber, B. A., Metzger, E. J., Susanto, R. D., Hurlburt, H. E., and Adi, T. R.: South China Sea throughflow impact on the Indonesian throughflow, Geophys. Res. Lett., 39, L11602, https://doi.org/10.1029/2012gl052021, 2012.
Gordon, H. R.: Atmospheric correction of ocean color imagery in the Earth Observing System era, J. Geophys. Res.-Atmos., 102, 17081–17106, https://doi.org/10.1029/96jd02443, 1997.
Löwemark, L., Hong, W. L., Yui, T. F., and Hung, G. W.: A test of different factors influencing the isotopic signal of planktonic foraminifera, in surface sediments from the northern South China Sea, Mar. Micropaleontol., 55, 49–62, 2005.
Liu, C. T. and Liu, R. J.: The deep current in the Bashi Channel, Acta Oceanogr. Taiwanica, 20, 107–116, 1988.
Liu, G. and Chai, F.: Seasonal and interannual variability of primary and export production in the South China Sea: a three-dimensional physical-biogeochemical model study, Ices J. Mar. Sci., 66, 420–431, https://doi.org/10.1093/icesjms/fsn219, 2009.
Liu, K.-K., Chen, Y.-J., Tseng, C.-M., Lin, I.-I., Liu, H., and Snidvongs, A.: The significance of phytoplankton photo-adaptation and benthic-pelagic coupling to primary production in the South China Sea: Observations and numerical investigations, Deep-Sea Res. II, 54, 1546–1574, https://doi.org/10.1016/j.dsr2.2007.05.009, 2007.
Liu, K.-K., Tseng, C.-M., Wu, C.-R., and Lin, I.-I.: 8.6. The South China Sea, in: Carbon and Nutrient Fluxes in Continental Margins: A Global Synthesis, edited by: Liu, K.-K., Atkinson, L., Quiñones, R., and Talaue-McManus, L., IGBP Book Series, Springer, Berlin, 464–482, 2010a.
Liu, K.-K., Tseng, C.-M., Yeh, T.-Y., and Wang, L.-W.: Elevated phytoplankton biomass in marginal seas in the low latitude ocean: A case study of the South China Sea, in: Advances in Geosciences Vol. 18, Ocean Science, edited by: Gan, J., 1–17, 2010b.
Liu, K. K., Chao, S. Y., Shaw, P. T., Gong, G. C., Chen, C. C., and Tang, T. Y.: Monsoon-forced chlorophyll distribution and primary production in the South China Sea: observations and a numerical study, Deep-Sea Res. Pt. I, 49, 1387–1412, 2002.
Lowemark, L., Steinke, S., Wang, C. H., Chen, M. T., Muller, A., Shiau, L. J., Kao, S. J., Song, S. R., Lin, H. L., and Wei, K. Y.: New evidence for a glacioeustatic influence on deep water circulation, bottom water ventilation and primary productivity in the South China Sea, Dynam. Atmos. Oceans, 47, 138–153, https://doi.org/10.1016/j.dynatmoce.2008.08.004, 2009.
Mellor, G. L. and Yamada, T.: Development of a turbulence closure model for geophysical fluid problems, Rev. Geophys. Space Phys., 20, 851–875, 1982.
Ning, X., Chai, F., Xue, H., Cai, Y., Liu, C., and Shi, J.: Physical-biological oceanographic coupling influencing phytoplankton and primary production in the South China Sea, J. Geophys. Res.-Oceans, 109, C10005, https://doi.org/10.1029/2004jc002365, 2004.
Pai, S. C., Yang, C. C., and Riley, J. P.: Formation kinetics of the pink azo dye in the determination of nitrite in natural-waters, Anal. Chim. Acta, 232, 345–349, 1990.
Palacz, A. P., Xue, H. J., Armbrecht, C., Zhang, C. Y., and Chai, F.: Seasonal and inter-annual changes in the surface chlorophyll of the South China Sea, J. Geophys. Res.-Oceans, 116, C09015, https://doi.org/10.1029/2011jc007064, 2011.
Qu, T., Mitsudera, H., and Yamagata, T.: Intrusion of the North Pacific waters into the South China Sea, J. Geophys. Res.-Oceans, 105, 6415–6424, https://doi.org/10.1029/1999jc900323, 2000.
Qu, T. D., Kim, Y. Y., Yaremchuk, M., Tozuka, T., Ishida, A., and Yamagata, T.: Can Luzon Strait transport play a role in conveying the impact of ENSO to the South China Sea?, J. Climate, 17, 3644–3657, 2004.
Qu, T. D., Du, Y., Meyers, G., Ishida, A., and Wang, D. X.: Connecting the tropical Pacific with Indian Ocean through South China Sea, Geophys. Res. Lett., 32, https://doi.org/10.1029/2005GL024698, 2005.
Qu, T. D., Girton, J. B., and Whitehead, J. A.: Deepwater overflow through Luzon Strait, J. Geophys. Res.-Oceans, 111, https://doi.org/10.1029/2005JC003139, 2006.
Shaw, P. T.: The Seasonal-Variation of the Intrusion of the Philippine Sea-Water into the South China Sea, J. Geophys. Res.-Oceans, 96, 821–827, 1991.
Shaw, P. T. and Chao, S. Y.: Surface Circulation in the South China Sea, Deep Sea Res. Pt. 1, 41, 1663–1683, 1994.
Shaw, P. T., Chao, S. Y., Liu, K. K., Pai, S. C., and Liu, C. T.: Winter Upwelling Off Luzon in the Northeastern South China Sea, J. Geophys. Res.-Oceans, 101, 16435–16448, 1996.
Strickland, J. D. H., and Parsons, T. R.: A practical handbook of seawater analysis, 3rd Edn., Bulletin of Fisheries Research Board, Canada, Ottawa, 1984.
Sun, D. H., Gagan, M. K., Cheng, H., Scott-Gagan, H., Dykoski, C. A., Edwards, R. L., and Sua, R. X.: Seasonal and interannual variability of the Mid-Holocene East Asian monsoon in coral δ18O records from the South China Sea, Earth Planet. Sci. Lett., 237, 69–84, https://doi.org/10.1016/j.epsl.2005.06.022, 2005.
Tang, D. L., Ni, I. H., Kester, D. R., and Muller-Karger, F. E.: Remote sensing observations of winter phytoplankton blooms southwest of the Luzon Strait in the South China Sea, Mar. Ecol.-Prog. Ser., 191, 43–51, https://doi.org/10.3354/meps191043, 1999.
Thomas, A. C., Strub, P. T., Weatherbee, R. A., and James, C.: Satellite views of Pacific chlorophyll variability: Comparisons to physical variability, local versus nonlocal influences and links to climate indices, Deep-Sea Res. Pt II, 77, 99–116, https://doi.org/10.1016/j.dsr2.2012.04.008, 2012.
Thompson, R. O. R. Y.: Low-pass filters to suppress inertial and tidal frequencies, J Phys. Oceanogr., 13, 1077–1083, 1983.
Tian, J. W. and Qu, T. D.: Advances in research on the deep South China Sea circulation, Chinese Sci. Bull., 57, 3115–3120, https://doi.org/10.1007/s11434-012-5269-x, 2012.
Tseng, C. M., Wong, G. T. F., Lin, II, Wu, C. R., and Liu, K. K.: A unique seasonal pattern in phytoplankton biomass in low-latitude waters in the South China Sea, Geophys. Res. Lett., 32, L08608, https://doi.org/10.1029/2004GL022111, 2005.
Tseng, C. M., Gong, G. C., Wang, L. W., Liu, K. K., and Yang, Y.: Anomalous biogeochemical conditions in the northern South China Sea during the El-Nino events between 1997 and 2003, Geophys. Res. Lett., 36, L14611, https://doi.org/10.1029/2009gl038252, 2009a.
Tseng, C. M., Liu, K. K., Wang, L. W., and Gong, G. C.: Anomalous hydrographic and biological conditions in the northern South China Sea during the 1997-1998 El Niño and comparisons with the equatorial Pacific, Deep-Sea Res. Pt I, 56, 2129–2143, https://doi.org/10.1016/j.dsr.2009.09.004, 2009b.
Walters, R. A. and Heston, C.: Removing tidal-period variations from time-series data using low-pass digital filters, J. Phys. Oceanogr., 12, 112–115, 1982.
Wang, P. X., Tian, J., Cheng, X. R., Liu, C. L., and Xu, J.: Major Pleistocene stages in a carbon perspective: The South China Sea record and its global comparison, Paleoceanography, 19, PA4005, https://doi.org/10.1029/2003PA000991, 2004.
Wolter, K. and Timlin, M. S.: El Niño/Southern Oscillation behaviour since 1871 as diagnosed in an extended multivariate ENSO index (MEI.ext), Int. J. Climatol., 31, 1074–1087, https://doi.org/10.1002/joc.2336, 2011.
Wong, G. T. F., Ku, T.-L., Mulholland, M., Tseng, C.-M., and Wang, D.-P.: The SouthEast Asian Time-series Study (SEATS) and the biogeochemistry of the South China Sea: an overview, Deep-Sea Res. Pt II, 54, 1434–1447, 2007.
Wu, C. R. and Hsin, Y. C.: The forcing mechanism leading to the Kuroshio intrusion into the South China Sea, J. Geophys. Res.-Oceans, 117, C07015, https://doi.org/10.1029/2012jc007968, 2012.
Xiu, P., Chai, F., Shi, L., Xue, H. J., and Chao, Y.: A census of eddy activities in the South China Sea during 1993-2007, J. Geophys. Res.-Oceans, 115, C03012, https://doi.org/10.1029/2009jc005657, 2010.
Xiu, P., and Chai, F.: Modeled biogeochemical responses to mesoscale eddies in the South China Sea, J. Geophys. Res.-Oceans, 116, C10006, https://doi.org/10.1029/2010jc006800, 2011.
Xue, H. J., Chai, F., Pettigrew, N., Xu, D. Y., Shi, M., and Xu, J. P.: Kuroshio intrusion and the circulation in the South China Sea, J. Geophys. Res.-Oceans, 109, https://doi.org/10.1029/2002JC001724, 2004.
Yan, X. H., Ho, C. R., Zheng, Q., and Klemas, V.: Temperature and size variabilities of the western Pacific Warm Pool, Science, 258, 1643–1645, 1992.
You, Y. Z., Chern, C. S., Yang, Y., Liu, C. T., Liu, K. K., and Pai, S. C.: The South China Sea, a cul-de-sac of North Pacific Intermediate Water, J. Oceanogr., 61, 509–527, 2005.
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