Articles | Volume 14, issue 10
https://doi.org/10.5194/bg-14-2597-2017
© Author(s) 2017. 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-14-2597-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
22 May 2017
Research article |
| 22 May 2017
The influence of episodic flooding on a pelagic ecosystem in the East China Sea
Department of Life Science, National Taiwan Normal University, Taipei 116, Taiwan
Gwo-Ching Gong
Institute of Marine Environment and Ecology, National Taiwan Ocean
University, Keelung 20224, Taiwan
Wen-Chen Chou
Institute of Marine Environment and Ecology, National Taiwan Ocean
University, Keelung 20224, Taiwan
Chih-Ching Chung
Institute of Marine Environment and Ecology, National Taiwan Ocean
University, Keelung 20224, Taiwan
Chih-Hao Hsieh
Institute of Oceanography, National Taiwan University, Taipei 10617, Taiwan
Fuh-Kwo Shiah
Institute of Marine Environment and Ecology, National Taiwan Ocean
University, Keelung 20224, Taiwan
Research Center for Environmental Changes, Academia Sinica, Nankang Taipei 115, Taiwan
Kuo-Ping Chiang
Institute of Marine Environment and Ecology, National Taiwan Ocean
University, Keelung 20224, Taiwan
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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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Feifei Liu, Ute Daewel, Jan Kossack, Kubilay Timur Demir, Helmuth Thomas, and Corinna Schrum
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Mariche Bandibas Natividad, Jian-Jhih Chen, Hsin-Yu Chou, Lan-Feng Fan, Yi-Le Shen, and Wen-Chen Chou
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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.
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.
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.
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.
Cited articles
Alcaraz, M., Saiz, E., Calbet, A., Trepat, I., and Broglio, E.: Estimating zooplankton biomass through image analysis, Mar. Biol., 143, 307–315, 2003.
Beardsley, R. C., Limeburner, R., Yu, H., and Cannon, G. A.: Discharge of the Changjiang (Yangtze River) into the East China Sea, Cont. Shelf Res., 4, 57–76, 1985.
Calbet, A. and Landry, M. R.: Phytoplankton growth, microzooplankton grazing, and carbon cycling in marine systems, Limnol. Oceanogr., 49, 51–57, 2004.
Chang, J., Shiah, F. K., Gong, G. C., and Chiang, K. P.: Cross-shelf variation in carbon-to-chlorophyll a ratios in the East China Sea, summer 1998, Deep-Sea Res. Pt. II, 50, 1237–1247, 2003.
Chen, C.-C., Shiah, F. K., Gong, G. C., and Chiang, K. P.: Planktonic community respiration in the East China Sea: importance of microbial consumption of organic carbon, Deep-Sea Res. Pt. II, 50, 1311–1325, 2003.
Chen, C.-C., Shiah, F. K., Chiang, K. P., Gong, G. C., and Kemp, W. M.: Effects of the Changjiang (Yangtze) River discharge on planktonic community respiration in the East China Sea, J. Geophys. Res.-Oceans, 114, C03005, https://doi.org/10.1029/2008jc004891, 2009.
Chen, C.-C., Gong, G.-C., Shiah, F.-K., Chou, W.-C., and Hung, C.-C.: The large variation in organic carbon consumption in spring in the East China Sea, Biogeosciences, 10, 2931–2943, https://doi.org/10.5194/bg-10-2931-2013, 2013.
Chen, C.-C., Chiang, K. P., Gong, G. C., Shiah, F. K., Tseng, C. M., and Liu, K. K.: Importance of planktonic community respiration on the carbon balance of the East China Sea in summer, Global Biogeochem. Cy., 20, Gb4001, https://doi.org/10.1029/2005gb002647, 2006.
Chen, C. S., Zhu, J. R., Beardsley, R. C., and Franks, P. J. S.: Physical-biological sources for dense algal blooms near the Changjiang River, Geophys. Res. Lett., 30, 1515–1518, 2003.
Chen, Y. L. L., Chen, H. Y., Gong, G. C., Lin, Y. H., Jan, S., and Takahashi, M.: Phytoplankton production during a summer coastal upwelling in the East China Sea, Cont. Shelf Res., 24, 1321–1338, 2004.
Chou, W. C., Sheu, D. D., Chen, C. T. A., Wen, L. S., Yang, Y., and Wei, C. L.: Transport of the South China Sea subsurface water outflow and its influence on carbon chemistry of Kuroshio waters off southeastern Taiwan, J. Geophys. Res.-Oceans, 112, C12008, https://doi.org/10.1029/2007jc004087, 2007.
Christensen, J. H. and Christensen, O. B.: Climate modelling: Severe summertime flooding in Europe, Nature, 421, 805–806, 2003.
Chung, C. C., Gong, G. C., and Hung, C. C.: Effect of Typhoon Morakot on microphytoplankton population dynamics in the subtropical Northwest Pacific, Mar. Ecol.-Prog. Ser., 448, 39–49, 2012.
Chung, C. C., Huang, C. Y., Gong, G. C., and Lin, Y. C.: Influence of the Changjiang River Flood on Synechococcus Ecology in the Surface Waters of the East China Sea, Microb. Ecol., 67, 273–285, 2014.
Dagg, M., Benner, R., Lohrenz, S., and Lawrence, D.: Transformation of dissolved and particulate materials on continental shelves influenced by large rivers: plume processes, Cont. Shelf Res., 24, 833–858, 2004.
Dickson, A. G. and Millero, F. J.: A Comparison of the Equilibrium-Constants for the Dissociation of Carbonic-Acid in Seawater Media, Deep-Sea Res, 34, 1733–1743, 1987.
Fisher, T. R., Peele, E. R., Ammerman, J. W., and Harding, L. W., Jr.: Nutrient limitation of phytoplankton in Chesapeake Bay, Mar. Ecol.-Prog. Ser., 82, 51–63, 1992.
Gaarder, T. and Grann, H. H.: Investigations of the production of plankton in the Oslo Fjord, Rapport et Proces-Verbaux des Reunions, Conseil Permanent International pour l'Exploration de la Mer, 42, 3–31, 1927.
Gao, X. L. and Song, J. M.: Phytoplankton distributions and their relationship with the environment in the Changjiang Estuary, China, Mar. Pollut. Bull., 50, 327–335, 2005.
Garcia-Comas, C.: Short manual to work with the ZooScan, Zooprocess version 6.16, http://www.zooscan.com (last access: 18 May 2017), 2010.
Gong, G.-C., Chen, Y.-L. L., and Liu, K.-K.: Chemical hydrography and chlorophyll a distribution in the East China Sea in summer: implication in nutrient dynamics, Cont. Shelf Res., 16, 1561–1590, 1996.
Gong, G.-C., Wen, Y.-H., Wang, B.-W., and Liu, G.-J.: Seasonal variation of chlorophyll a concentration, primary production and environmental conditions in the subtropical East China Sea, Deep-Sea Res. Pt. II, 50, 1219–1236, 2003.
Gong, G. C., Liu, K. K., Chiang, K. P., Hsiung, T. M., Chang, J., Chen, C. C., Hung, C. C., Chou, W. C., Chung, C. C., Chen, H. Y., Shiah, F. K., Tsai, A. Y., Hsieh, C. H., Shiao, J. C., Tseng, C. M., Hsu, S. C., Lee, H. J., Lee, M. A., Lin, I. I., and Tsai, F. J.: Yangtze River floods enhance coastal ocean phytoplankton biomass and potential fish production, Geophys. Res. Lett., 38, L13603, https://doi.org/10.1029/2011GL047519, 2011.
Goyet, C., Millero, F. J., Poisson, A., and Shafer, D. K.: Temperature dependence of CO2 fugacity in seawater, Mar. Chem., 44, 205–219, 1993.
Harding Jr., L. W.: Long-term trends in the distribution of phytoplankton in Chesapeake Bay: roles of light, nutrients and streamflow, Mar. Ecol.-Prog. Ser., 104, 267–291, 1994.
Harrison, P. J., Hu, M. H., Yang, Y. P., and Lu, X.: Phosphate limitation in estuarine and coastal waters of China, J. Exp. Mar. Biol. Ecol., 140, 79–87, 1990.
Hedges, J. I., Keil, R. G., and Benner, R.: What happens to terrestrial organic matter in the ocean?, Org. Geochem., 27, 195–212, 1997.
Hedges, J. I., Cowie, G. L., Richey, J. E., Quay, P. D., Benner, R., Strom, M., and Forsberg, B. R.: Origins and processing of organic-matter in the Amazon River as indicated by carbohydrates and amino-acids, Limnol. Oceanogr., 39, 743–761, 1994.
Hernández-León, S. and Ikeda, T.: A global assessment of mesozooplankton respiration in the ocean, J. Plankton Res., 27, 153–158, 2005.
Hobbie, J. E., Daley, R. J., and Jasper, S.: Use of nuclepore filters for counting bacteria by fluorescence microscopy, Appl. Environ. Microbiol., 33, 1225–1228, 1977.
Hopkinson Jr., C. S.: Shallow-water benthic and pelagic metabolism: evidence of heterotrophy in the nearshore Georgia Bight, Mar. Biol., 87, 19–32, 1985.
Hopkinson Jr., C. S., Sherr, B., and Wiebe, W. J.: Size fractionated metabolism of coastal microbial plankton, Mar. Ecol.-Prog. Ser., 51, 155–166, 1989.
Hsieh, W. C., Chen, C. C., Shiah, F. K., Hung, J. J., Chiang, K. P., Meng, P. J., and Fan, K. S.: Community metabolism in a tropical lagoon: carbon cycling and autotrophic ecosystem induced by a natural nutrient pulse, Environ. Eng. Sci., 29, 776–782, 2012.
Knox, J. C.: Large Increases in Flood Magnitude in Response to Modest Changes in Climate, Nature, 361, 430–432, 1993.
Lee, S. and Fuhrman, J. A.: Relationship between biovolume and biomass of naturally derived marine bacterioplankton, Appl. Environ. Microbiol., 53, 1298–1303, 1987.
Levitus, S.: Climatological atlas of the word ocean, NOAA professional paper No. 13, US Government Printing Office, Washington, DC, 173 pp., 1982.
Lewis, E. and Wallace, D. W. R.: Program developed for CO2 system calculations, Rep. ORNL/CDIAC-105, Carbon Dioxide Inf. Anal. Cent., Oak Ridge Natl. Lab., Oak Ridege, Tenn., 1998.
Liu, H. B., Suzukil, K., Minami, C., Saino, T., and Watanabe, M.: Picoplankton community structure in the subarctic Pacific Ocean and the Bering Sea during summer 1999, Mar. Ecol.-Prog. Ser., 237, 1–14, 2002.
Liu, K.-K., Gong, G.-C., Wu, C.-R., and Lee, H.-J.: The Kuroshio and the East China Sea, in: Carbon and Nutrient Fluxes in Continental Margins: A Global Synthesis, edited by: Liu, K. K., Atkinson, L., Quiñones, R., and TalaueMcManus, L., Springer, Berlin, 124–146, 2010.
Lopez-Sandoval, D. C., Rodriguez-Ramos, T., Cermeno, P., Sobrino, C., and Maranon, E.: Photosynthesis and respiration in marine phytoplankton: Relationship with cell size, taxonomic affiliation, and growth phase, J. Exp. Mar. Biol. Ecol., 457, 151–159, 2014.
Malone, T. C. and Ducklow, H. W.: Microbial biomass in the coastal plume of Chesapeake Bay : phytoplankton-bacterioplankton relationships, Limnol. Oceanogr., 35, 296–312, 1990.
Mehrbach, C., Culberson, C. H., Hawley, J. E., and Pytkowicz, R. M.: Measurement of Apparent Dissociation-Constants of Carbonic-Acid in Seawater at Atmospheric-Pressure, Limnol. Oceanogr., 18, 897–907, 1973.
Meng, P.-J., Tew, K. S., Hsieh, H.-Y., and Chen, C.-C.: Relationship between magnitude of phytoplankton blooms and rainfall in a hyper-eutrophic lagoon: A continuous monitoring approach, Mar. Pollut. Bull., in press, https://doi.org/10.1016/j.marpolbul.2016.12.040, 2016.
Meng, P. J., Lee, H. J., Tew, K. S., and Chen, C. C.: Effect of a rainfall pulse on phytoplankton bloom succession in a hyper-eutrophic subtropical lagoon, Mar. Freshwater Res., 66, 60–69, 2015.
Milly, P. C. D., Wetherald, R. T., Dunne, K. A., and Delworth, T. L.: Increasing risk of great floods in a changing climate, Nature, 415, 514–517, 2002.
Mulholland, M. R., Morse, R. E., Boneillo, G. E., Bernhardt, P. W., Filippino, K. C., Procise, L. A., Blanco-Garcia, J. L., Marshall, H. G., Egerton, T. A., Hunley, W. S., Moore, K. A., Berry, D. L., and Gobler, C. J.: Understanding causes and impacts of the dinoflagellate, Cochlodinium polykrikoides, blooms in the Chesapeake Bay, Estuar. Coast., 32, 734–747, 2009.
Müller-Karger, F. E., McClain, C. R., and Richardson, P. L.: The dispersal of the Amazon's water, Nature, 333, 56–59, 1988.
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, Biogeochem., 35, 141–180, 1996.
Pai, S.-C., Gong, G.-C., and Liu, K.-K.: Determination of dissolved oxygen in seawater by direct spectrophotometry of total iodine, Mar. Chem., 41, 343–351, 1993.
Palmer, T. N. and Ralsanen, J.: Quantifying the risk of extreme seasonal precipitation events in a changing climate, Nature, 415, 512–514, 2002.
Parsons, T. R., Maita, Y., and Lalli, C. M.: A manual of chemical and biological methods for seawater analysis, Pergamon Press, New York, 173 pp., 1984.
Pierrot, D. E., Levis, E., and Wallace, D. W. R.: MS Excel Program Developed for CO2 System Calculations, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, 2006.
Rowe, G. T., Smith, S., Falkowski, P., Whitledge, T., Theroux, R., Phoel, W., and Ducklow, H.: Do continental shelves export organic matter?, Nature, 324, 559–561, 1986.
Sherr, E. B. and Sherr, B. F.: Role of heterotrophic protozoa in carbon and energy flow in aquatic ecosystems, in: Current perspectives in microbial ecology, edited by: Klug, M. J. and Reddy, C. A., American society for microbiology, Washington, D.C., 412–423, 1984.
Smith, E. M. and Kemp, W. M.: Seasonal and regional variations in plankton community production and respiration for the Chesapeake Bay, Mar. Ecol.-Prog. Ser., 116, 217–231, 1995.
Tian, R. C., Hu, F. X., and Martin, J. M.: Summer nutrient fronts in the Changjiang (Yangtze River) Estuary, Estuar. Coast. Shelf Sci., 37, 27–41, 1993.
Tsai, A. Y., Chiang, K. P., Chang, J., and Gong, G. C.: Seasonal diel variations of picoplankton and nanoplankton in a subtropical western Pacific coastal ecosystem, Limnol. Oceanogr., 50, 1221–1231, 2005.
Wang, X. C., Ma, H. Q., Li, R. H., Song, Z. S., and Wu, J. P.: Seasonal fluxes and source variation of organic carbon transported by two major Chinese Rivers: The Yellow River and Changjiang (Yangtze) River, Global Biogeochem. Cy., 26, Gb2025, https://doi.org/10.1029/2011gb004130, 2012.
Xu, K. H. and Milliman, J. D.: Seasonal variations of sediment discharge from the Yangtze River before and after impoundment of the Three Gorges Dam, Geomorphology, 104, 276–283, 2009.
Yu, F. L., Chen, Z. Y., Ren, X. Y., and Yang, G. F.: Analysis of historical floods on the Yangtze River, China: Characteristics and explanations, Geomorphology, 113, 210–216, 2009.
Zhai, W. D., Dai, M. H., and Guo, X. G.: Carbonate system and CO2 degassing fluxes in the inner estuary of Changjiang (Yangtze) River, China, Mar. Chem., 107, 342–356, 2007.
Short summary
To understand the flooding effects on a pelagic ecosystem in the East China Sea (ECS), a variety of variables were measured in 2009 (non-flood) and 2010 (flood). In 2010, the organic carbon consumption was higher than in 2009; this could be attributed to the vigorous plankton activities observed in low-salinity areas. A huge amount of f CO2 was also drawn down in the flood. This flood effect might become more pronounced as extreme rainfall events increase dramatically throughout the world.
To understand the flooding effects on a pelagic ecosystem in the East China Sea (ECS), a variety...
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