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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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
Short summary
Short summary
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
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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