Articles | Volume 16, issue 22
https://doi.org/10.5194/bg-16-4411-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-16-4411-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
20 Nov 2019
Research article |
| 20 Nov 2019
| 20 Nov 2019
Net heterotrophy and carbonate dissolution in two subtropical seagrass meadows
Bryce R. Van Dam
CORRESPONDING AUTHOR
Center for Coastal Oceans Research, Department of Biological Sciences,
Florida International University, 11200 SW 8th St, Miami, FL 33199, USA
Institute of Coastal Research, Helmholtz-Zentrum Geesthacht (HZG),
Geesthacht, 21502, Germany
Christian Lopes
Institute of Coastal Research, Helmholtz-Zentrum Geesthacht (HZG),
Geesthacht, 21502, Germany
Christopher L. Osburn
Department of Marine, Earth, and Atmospheric Sciences, North Carolina State
University, 2800 Faucette Drive, Raleigh, NC 27695, USA
James W. Fourqurean
Institute of Coastal Research, Helmholtz-Zentrum Geesthacht (HZG),
Geesthacht, 21502, Germany
Related authors
Julia Meyer, Yoana G. Voynova, Bryce Van Dam, Lara Luitjens, Dagmar Daehne, and Helmuth Thomas
EGUsphere, https://doi.org/10.5194/egusphere-2024-3048, https://doi.org/10.5194/egusphere-2024-3048, 2024
Short summary
Short summary
The study highlights the inter-seasonal variability of the carbonate dynamics of the East Frisian Wadden Sea, the world's largest intertidal area. During spring, increased biological activity leads to lower CO2 and nitrate levels, while total alkalinity (TA) rises slightly. In summer, TA increases, enhancing the ocean's ability to absorb CO2. Our research emphasizes the vital role of these intertidal regions in regulating carbon, contributing to a better understanding of carbon storage.
Bryce Van Dam, Nele Lehmann, Mary A. Zeller, Andreas Neumann, Daniel Pröfrock, Marko Lipka, Helmuth Thomas, and Michael Ernst Böttcher
Biogeosciences, 19, 3775–3789, https://doi.org/10.5194/bg-19-3775-2022, https://doi.org/10.5194/bg-19-3775-2022, 2022
Short summary
Short summary
We quantified sediment–water exchange at shallow sites in the North and Baltic seas. We found that porewater irrigation rates in the former were approximately twice as high as previously estimated, likely driven by relatively high bioirrigative activity. In contrast, we found small net fluxes of alkalinity, ranging from −35 µmol m−2 h−1 (uptake) to 53 µmol m−2 h−1 (release). We attribute this to low net denitrification, carbonate mineral (re-)precipitation, and sulfide (re-)oxidation.
Julia Meyer, Yoana G. Voynova, Bryce Van Dam, Lara Luitjens, Dagmar Daehne, and Helmuth Thomas
EGUsphere, https://doi.org/10.5194/egusphere-2024-3048, https://doi.org/10.5194/egusphere-2024-3048, 2024
Short summary
Short summary
The study highlights the inter-seasonal variability of the carbonate dynamics of the East Frisian Wadden Sea, the world's largest intertidal area. During spring, increased biological activity leads to lower CO2 and nitrate levels, while total alkalinity (TA) rises slightly. In summer, TA increases, enhancing the ocean's ability to absorb CO2. Our research emphasizes the vital role of these intertidal regions in regulating carbon, contributing to a better understanding of carbon storage.
Bryce Van Dam, Nele Lehmann, Mary A. Zeller, Andreas Neumann, Daniel Pröfrock, Marko Lipka, Helmuth Thomas, and Michael Ernst Böttcher
Biogeosciences, 19, 3775–3789, https://doi.org/10.5194/bg-19-3775-2022, https://doi.org/10.5194/bg-19-3775-2022, 2022
Short summary
Short summary
We quantified sediment–water exchange at shallow sites in the North and Baltic seas. We found that porewater irrigation rates in the former were approximately twice as high as previously estimated, likely driven by relatively high bioirrigative activity. In contrast, we found small net fluxes of alkalinity, ranging from −35 µmol m−2 h−1 (uptake) to 53 µmol m−2 h−1 (release). We attribute this to low net denitrification, carbonate mineral (re-)precipitation, and sulfide (re-)oxidation.
A. R. Armitage and J. W. Fourqurean
Biogeosciences, 13, 313–321, https://doi.org/10.5194/bg-13-313-2016, https://doi.org/10.5194/bg-13-313-2016, 2016
Short summary
Short summary
The emerging field of blue carbon research seeks to quantify the carbon sequestration in coastal habitats. Seagrasses are highly productive, and have a particularly large carbon storage capacity, relative to area. This study evaluated the influence of nutrient input on seagrass carbon stocks in Florida Bay (USA). There was high carbon content in the soils, indicating that seagrass beds have extremely high carbon storage potential, even in nutrient-limited areas with low biomass or productivity.
I. Mazarrasa, N. Marbà, C. E. Lovelock, O. Serrano, P. S. Lavery, J. W. Fourqurean, H. Kennedy, M. A. Mateo, D. Krause-Jensen, A. D. L. Steven, and C. M. Duarte
Biogeosciences, 12, 4993–5003, https://doi.org/10.5194/bg-12-4993-2015, https://doi.org/10.5194/bg-12-4993-2015, 2015
Short summary
Short summary
There has been growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the organic fraction and ignored the inorganic carbon pool. This study offers the first global assessment of PIC stocks and accumulation rates in seagrass sediments, identifying these ecosystems as important contributors to carbonate dynamics in coastal areas.
Related subject area
Biogeochemistry: Coastal Ocean
Improved understanding of nitrate trends, eutrophication indicators, and risk areas using machine learning
Evaluating ocean alkalinity enhancement as a carbon dioxide removal strategy in the North Sea
Spring–neap tidal cycles modulate the strength of the carbon source at the estuary–coast interface
Spatiotemporal variations in surface marine carbonate system properties across the western Mediterranean Sea using volunteer observing ship data
Amplified bottom water acidification rates on the Bering Sea shelf from 1970–2022
Depositional controls and budget of organic carbon burial in fine-grained sediments of the North Sea – the Helgoland Mud Area as a natural laboratory
Effects of submarine groundwater on nutrient concentration and primary production in a deep bay of the Japan Sea
The bacteria–protist link as a main route of dissolved organic matter across contrasting productivity areas on the Patagonian Shelf
Ocean alkalinity enhancement (OAE) does not cause cellular stress in a phytoplankton community of the subtropical Atlantic Ocean
Reviews and syntheses: On increasing hypoxia in eastern boundary upwelling systems – zooplankton under metabolic stress
Zinc stimulation of phytoplankton in a low carbon dioxide, coastal Antarctic environment: evidence for the Zn hypothesis
Technical note: Testing a new approach for the determination of N2 fixation rates by coupling a membrane equilibrator to a mass spectrometer for long-term observations
A niche for diverse cable bacteria in continental margin sediments overlain by oxygen-deficient waters
Phytoplankton community succession and biogeochemistry in a bloom simulation experiment at an estuary-ocean interface
Long-term variations in pH in coastal waters along the Korean Peninsula
The effect of carbonate mineral additions on biogeochemical conditions in surface sediments and benthic–pelagic exchange fluxes
Estimation of Metabolic Dynamics of Restored Seagrass Meadows in a Southeast Asia Islet: Insights from Ex Situ Benthic Incubation
Assessing the impacts of simulated ocean alkalinity enhancement on viability and growth of nearshore species of phytoplankton
Human Activities Caused Hypoxia Expansion in a Large Eutrophic Estuary: Non-negligible Role of Riverine Suspended Sediments
Photosynthetic electron, carbon and oxygen fluxes within a mosaic of Fe limitation in the California Current Upwelling System
Responses of microbial metabolic rates to non-equilibrated silicate- versus calcium-based ocean alkalinity enhancement
High metabolic zinc demand within native Amundsen and Ross sea phytoplankton communities determined by stable isotope uptake rate measurements
The influence of zooplankton and oxygen on the particulate organic carbon flux in the Benguela Upwelling System
Reviews and syntheses: Biological indicators of low-oxygen stress in marine water-breathing animals
Temperature-enhanced effects of iron on Southern Ocean phytoplankton
Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth system model
The Northeast Greenland Shelf as a potential late-summer CO2 source to the atmosphere
Technical note: Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project (OAEPIIP)
Estimates of carbon sequestration potential in an expanding Arctic fjord (Hornsund, Svalbard) affected by dark plumes of glacial meltwater
An assessment of ocean alkalinity enhancement using aqueous hydroxides: kinetics, efficiency, and precipitation thresholds
Dissolved nitric oxide in the lower Elbe Estuary and the Port of Hamburg area
Variable contribution of wastewater treatment plant effluents to downstream nitrous oxide concentrations and emissions
Distribution of nutrients and dissolved organic matter in a eutrophic equatorial estuary: the Johor River and the East Johor Strait
Investigating the effect of silicate- and calcium-based ocean alkalinity enhancement on diatom silicification
Ocean alkalinity enhancement using sodium carbonate salts does not lead to measurable changes in Fe dynamics in a mesocosm experiment
Quantification and mitigation of bottom-trawling impacts on sedimentary organic carbon stocks in the North Sea
Influence of ocean alkalinity enhancement with olivine or steel slag on a coastal plankton community in Tasmania
Multi-model comparison of trends and controls of near-bed oxygen concentration on the northwest European continental shelf under climate change
Picoplanktonic methane production in eutrophic surface waters
Vertical mixing alleviates autumnal oxygen deficiency in the central North Sea
Hypoxia also occurs in small highly turbid estuaries: the example of the Charente (Bay of Biscay)
Seasonality and response of ocean acidification and hypoxia to major environmental anomalies in the southern Salish Sea, North America (2014–2018)
Oceanographic processes driving low-oxygen conditions inside Patagonian fjords
Above- and belowground plant mercury dynamics in a salt marsh estuary in Massachusetts, USA
Variability and drivers of carbonate chemistry at shellfish aquaculture sites in the Salish Sea, British Columbia
Unusual Hemiaulus bloom influences ocean productivity in Northeastern US Shelf waters
Insights into carbonate environmental conditions in the Chukchi Sea
UAV approaches for improved mapping of vegetation cover and estimation of carbon storage of small saltmarshes: examples from Loch Fleet, northeast Scotland
Iron “ore” nothing: benthic iron fluxes from the oxygen-deficient Santa Barbara Basin enhance phytoplankton productivity in surface waters
Marine anoxia initiates giant sulfur-oxidizing bacterial mat proliferation and associated changes in benthic nitrogen, sulfur, and iron cycling in the Santa Barbara Basin, California Borderland
Deep S. Banerjee and Jozef Skákala
Biogeosciences, 22, 3769–3784, https://doi.org/10.5194/bg-22-3769-2025, https://doi.org/10.5194/bg-22-3769-2025, 2025
Short summary
Short summary
Nitrate is a crucial nutrient in oceans, whose excess can trigger uncontrolled algae growth that damages marine ecosystems. We used machine learning to generate skilled, gap-free, bi-decadal surface nitrate data from sparse observations, revealing areas on the North-West European Shelf that are more vulnerable to excess algae growth if nutrient pollution occurs. We also looked at bi-decadal trends in coastal nitrate and the impact of winter nitrate on spring phytoplankton blooms.
Feifei Liu, Ute Daewel, Jan Kossack, Kubilay Timur Demir, Helmuth Thomas, and Corinna Schrum
Biogeosciences, 22, 3699–3719, https://doi.org/10.5194/bg-22-3699-2025, https://doi.org/10.5194/bg-22-3699-2025, 2025
Short summary
Short summary
Ocean alkalinity enhancement (OAE) 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.
Vlad A. Macovei, Louise C. V. Rewrie, Rüdiger Röttgers, and Yoana G. Voynova
Biogeosciences, 22, 3375–3396, https://doi.org/10.5194/bg-22-3375-2025, https://doi.org/10.5194/bg-22-3375-2025, 2025
Short summary
Short summary
We found that biogeochemical variability at the land–sea interface (LSI) in two major temperate estuaries is modulated by the 14 d spring–neap tidal cycle, with large effects on dissolved inorganic and organic carbon concentrations and distribution. As this effect increases the strength of the carbon source to the atmosphere by up to 74 % during spring tide, it should be accounted for in regional models, which aim to resolve biogeochemical processing at the LSI.
David Curbelo-Hernández, David González-Santana, Aridane G. González, J. Magdalena Santana-Casiano, and Melchor González-Dávila
Biogeosciences, 22, 3329–3356, https://doi.org/10.5194/bg-22-3329-2025, https://doi.org/10.5194/bg-22-3329-2025, 2025
Short summary
Short summary
This study offers a unique high-resolution dataset (2019–2024) on surface physicochemical properties in the western Mediterranean Sea. It reveals accelerated surface warming, significantly altering CO2 levels and pH. Currently a net CO2 sink, the region may become a CO2 source by 2030 due to weakening in-gassing. The research highlights the value of VOS (volunteer observing ship) lines for monitoring climate impacts and emphasizes the need for ongoing observations to enhance long-term trend accuracy and future projections.
Darren J. Pilcher, Jessica N. Cross, Natalie Monacci, Linquan Mu, Kelly A. Kearney, Albert J. Hermann, and Wei Cheng
Biogeosciences, 22, 3103–3125, https://doi.org/10.5194/bg-22-3103-2025, https://doi.org/10.5194/bg-22-3103-2025, 2025
Short summary
Short summary
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.
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
Biogeosciences, 22, 2541–2567, https://doi.org/10.5194/bg-22-2541-2025, https://doi.org/10.5194/bg-22-2541-2025, 2025
Short summary
Short summary
Coastal and shelf sediments are the most important sinks for organic carbon (OC) on Earth. We produced a new high-resolution sediment and porewater data set 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.
Menghong Dong, Xinyu Guo, Takuya Matsuura, Taichi Tebakari, and Jing Zhang
Biogeosciences, 22, 2383–2402, https://doi.org/10.5194/bg-22-2383-2025, https://doi.org/10.5194/bg-22-2383-2025, 2025
Short summary
Short summary
Submarine groundwater discharge (SGD), a common coastal hydrological process that involves submarine inflow of groundwater into the sea, is associated with a large nutrient load. To clarify the distribution of SGD-derived nutrients after release at the bottom of the sea and their contribution to phytoplankton growth in the marine ecosystem, we modeled the SGD process in Toyama Bay using a specialized computer code that can distinguish SGD-derived nutrients from nutrients from other sources.
M. Celeste López-Abbate, John E. Garzón-Cardona, Ricardo Silva, Juan-Carlos Molinero, Laura A. Ruiz-Etcheverry, Ana M. Martínez, Azul S. Gilabert, and Rubén J. Lara
Biogeosciences, 22, 2309–2325, https://doi.org/10.5194/bg-22-2309-2025, https://doi.org/10.5194/bg-22-2309-2025, 2025
Short summary
Short summary
This study explores how microbial dynamics influence the dissolved organic matter (DOM) pool in the Patagonian Shelf. Despite high phytoplankton biomass, selective grazing on fast-growing bacteria led to DOM accumulation, likely due to reduced DOM-consuming bacteria and added egestion compounds. Experiments showed that bacteria not only acted as a carbon sink through mineralization but also transferred assimilated carbon dioxide (CO2) to higher trophic levels.
Librada Ramírez, Leonardo J. Pozzo-Pirotta, Aja Trebec, Víctor Manzanares-Vázquez, José L. Díez, Javier Arístegui, Ulf Riebesell, Stephen D. Archer, and María Segovia
Biogeosciences, 22, 1865–1886, https://doi.org/10.5194/bg-22-1865-2025, https://doi.org/10.5194/bg-22-1865-2025, 2025
Short summary
Short summary
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 plankton community studied.
Leissing Frederick, Mauricio A. Urbina, and Ruben Escribano
Biogeosciences, 22, 1839–1852, https://doi.org/10.5194/bg-22-1839-2025, https://doi.org/10.5194/bg-22-1839-2025, 2025
Short summary
Short summary
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 population and the marine food web.
Riss M. Kell, Adam V. Subhas, Nicole L. Schanke, Lauren E. Lees, Rebecca J. Chmiel, Deepa Rao, Margaret M. Brisbin, Dawn M. Moran, Matthew R. McIlvin, Francesco Bolinesi, Olga Mangoni, Raffaella Casotti, Cecilia Balestra, Tristan Horner, Robert B. Dunbar, Andrew E. Allen, Giacomo R. DiTullio, and Mak A. Saito
EGUsphere, https://doi.org/10.1101/2023.11.05.565706, https://doi.org/10.1101/2023.11.05.565706, 2025
Short summary
Short summary
Photosynthetic productivity is strongly influenced by water column nutrient availability. Despite the importance of zinc, definitive evidence for oceanic zinc limitation of photosynthesis has been scarce. We applied multiple biogeochemical measurements to a field site in Terra Nova Bay, Antarctica, to demonstrate that the phytoplankton community was experiencing zinc limitation. This field evidence paves the way for future experimental studies to consider Zn as a limiting oceanic micronutrient.
Sören Iwe, Oliver Schmale, and Bernd Schneider
Biogeosciences, 22, 1767–1779, https://doi.org/10.5194/bg-22-1767-2025, https://doi.org/10.5194/bg-22-1767-2025, 2025
Short summary
Short summary
We present a novel method for quantifying N2 fixation by cyanobacteria, which is crucial in Baltic Sea eutrophication. Our Gas Equilibrium – Membrane-Inlet Mass Spectrometer (GE-MIMS), designed for operation on voluntary observing ships (VOSs), enables large-scale monitoring of surface water N2 depletion caused by N2 fixation. Laboratory tests confirm the device’s accuracy and precision, ensuring that it can complement current methods and contribute valuable data for better understanding N2 fixation in the Baltic Sea.
Caroline P. Slomp, Martijn Hermans, Niels A. G. M. van Helmond, Silke Severmann, James McManus, Marit R. van Erk, and Sairah Malkin
EGUsphere, https://doi.org/10.5194/egusphere-2025-817, https://doi.org/10.5194/egusphere-2025-817, 2025
Short summary
Short summary
Cable bacteria couple oxidation of sulfide at depth in sediments with reduction of oxygen, nitrate or nitrite near the sediment surface, thereby preventing release of toxic hydrogen sulfide to the overlying water. We show evidence for a diversity of cable bacteria in sediments from hypoxic and anoxic basins along the continental margin of California and Mexico. Cable bacteria activity in this setting is likely periodic and dependent on the supply of organic matter and/or oxygen.
Jenna Alyson Lee, Joseph H. Vineis, Mathieu A. Poupon, Laure Resplandy, and Bess B. Ward
EGUsphere, https://doi.org/10.5194/egusphere-2025-871, https://doi.org/10.5194/egusphere-2025-871, 2025
Short summary
Short summary
Concurrent sampling of environmental parameters, productivity rates, photopigments, and DNA were used to analyze a 24–L estuarine diatom bloom microcosm. Biogeochemical data and an ecological model indicated that the bloom was terminated by grazing. Comparisons to previous studies revealed (1) additional community and diversity complexity using 18S amplicon vs. traditional pigment–based analyses, and (2) a potential global productivity–diversity relationship using 18S and carbon transport rates.
Yong-Woo Lee, Mi-Ok Park, Seong-Gil Kim, Tae-Hoon Kim, Yong Hwa Oh, Sang Heon Lee, and DongJoo Joung
Biogeosciences, 22, 675–690, https://doi.org/10.5194/bg-22-675-2025, https://doi.org/10.5194/bg-22-675-2025, 2025
Short summary
Short summary
Long-term pH variation in coastal waters along the Korean Peninsula was assessed for the first time, and it exhibited no significant pH change over an 11-year period. This contrasts with the ongoing pH decline in open oceans and other coastal areas. Analysis of environmental data showed that pH is mainly controlled by dissolved oxygen in bottom waters. This suggests that ocean warming could cause a pH decline in Korean coastal waters, affecting many fish and seaweed aquaculture operations.
Kadir Biçe, Tristen Myers Stewart, George G. Waldbusser, and Christof Meile
Biogeosciences, 22, 641–657, https://doi.org/10.5194/bg-22-641-2025, https://doi.org/10.5194/bg-22-641-2025, 2025
Short summary
Short summary
We studied the effect of addition of carbonate minerals on coastal sediments. We carried out laboratory experiments to quantify the dissolution kinetics and integrated these observations into a numerical model that describes biogeochemical cycling in surficial sediments. Using the model, we demonstrate the buffering effect of the mineral additions and their duration. We quantify the effect under different environmental conditions and assess the potential for increased atmospheric CO2 uptake.
Mariche Bandibas Natividad, Jian-Jhih Chen, Hsin-Yu Chou, Lan-Feng Fan, Yi-Le Shen, and Wen-Chen Chou
EGUsphere, https://doi.org/10.5194/egusphere-2024-4000, https://doi.org/10.5194/egusphere-2024-4000, 2025
Short summary
Short summary
Seagrass restoration serves as a nature-based solution for CO2 removal. We examined the organic carbon and carbonate dynamics of restored seagrasses (SG) and bare sediments (BS) using ex situ core incubations. SG exhibited higher net ecosystem metabolism compared to BS, while no significant difference was observed in net ecosystem calcification. Consequently, SG demonstrated a significantly enhanced overall capacity for carbon uptake.
Jessica L. Oberlander, Mackenzie E. Burke, Cat A. London, and Hugh L. MacIntyre
Biogeosciences, 22, 499–512, https://doi.org/10.5194/bg-22-499-2025, https://doi.org/10.5194/bg-22-499-2025, 2025
Short summary
Short summary
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.
Yue Nan, Zheng Chen, Bin Wang, Bo Liang, and Jiatang Hu
EGUsphere, https://doi.org/10.5194/egusphere-2024-4013, https://doi.org/10.5194/egusphere-2024-4013, 2025
Short summary
Short summary
Human activities are changing the coastal water environment, but the role of suspended sediments in oxygen loss is not well understood. We used a model to compare dissolved oxygen levels and related factors in the 1990s and 2010s in the Pearl River Estuary. Reduced suspended sediments and increased pollution have expanded low-oxygen areas by 1.5 times. It highlights that declining suspended sediments increase hypoxia in estuaries, especially with rising nutrients, which need urgent attention.
Yayla Sezginer, Kate Schuler, Emily Speciale, Adrian Marchetti, Claire Till, Ralph Till, and Philippe Tortell
EGUsphere, https://doi.org/10.5194/egusphere-2024-3812, https://doi.org/10.5194/egusphere-2024-3812, 2025
Short summary
Short summary
We recorded three metrics of photosynthesis in the California Current. Real-time observations of microalgae physiology and productivity revealed signs of iron limitation where the continental shelf rapidly dropped off. Iron limitation influenced how efficiently light was absorbed and used for carbon fixation but did not appear to affect net photosynthetic oxygen production. Our results offer useful insights towards efforts to model carbon fixation rates from microalgae optical properties.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Cited articles
Barrón, C., Duarte, C. M., Frankignoulle, M., and Borges, A. V.: Organic
carbon metabolism and carbonate dynamics in a Mediterranean seagrass
(Posidonia oceanica) meadow, Estuar. Coasts, 29, 417–426,
https://doi.org/10.1007/BF02784990, 2006.
Bosence, D. W. J.: Biogenic Carbonate Production in Florida Bay, Bull. Mar.
Sci., 44, 419–433, 1989.
Bosence, D. W. J., Rowlands, R. J., and Quine, M. L.: Sedimentology and
budget of a Recent carbonate mound, Florida Keys, Sedimentology, 32,
317–343, https://doi.org/10.1111/j.1365-3091.1985.tb00515.x, 1985.
Bouillon, S., Dehairs, F., Velimirov, B., Abril, G., and Borges, A. V.:
Dynamics of organic and inorganic carbon across contiguous mangrove and
seagrass systems (Gazi Bay, Kenya), J. Geophys. Res.-Biogeo., 112,
1–14, https://doi.org/10.1029/2006JG000325, 2007.
Brodersen, K. E., Trevathan-tackett, S. M., Nielsen, D. A., Macreadie, P.
I., and Durako, M. J.: Oxygen Consumption and Sulfate Reduction in Vegetated
Coastal Habitats : Effects of Physical Disturbance, Front. Mar. Sci.,
6, 1–13, https://doi.org/10.3389/fmars.2019.00014, 2019.
Burdige, D. J. and Zimmerman, R. C.: Impact of Sea Grass Density on
Carbonate Dissolution in Bahamian Sediments, Limnol. Oceanogr., 47,
1751–1763, https://doi.org/10.4319/lo.2002.47.6.1751, 2002.
Burdige, D. J., Hu, X., and Zimmerman, R. C.: The widespread occurrence of
coupled carbonate dissolution/reprecipitation in surface sediments on the
Bahamas Bank, Am. J. Sci., 310, 492–521, https://doi.org/10.2475/06.2010.03, 2010.
Camp, E. F., Suggett, D. J., Gendron, G., Jompa, J., Manfrino, C., and
Smith, D. J.: Mangrove and Seagrass Beds Provide Different Biogeochemical
Services for Corals Threatened by Climate Change, Front. Mar. Sci.,
3, 1–16, https://doi.org/10.3389/fmars.2016.00052, 2016.
Challener, R. C., Robbins, L. L., and Mcclintock, J. B.: Variability of the
carbonate chemistry in a shallow, seagrass-dominated ecosystem: Implications
for ocean acidification experiments, Mar. Freshw. Res., 67, 163–172,
https://doi.org/10.1071/MF14219, 2016.
Chapin, F. S., Pace, M. L., Harden, J. W., Schulze, E.-D., Randerson, J.
T., Harmon, M. E., McGuire, A. D., Woodwell, G. M., Wirth, C., Clark, D. A.,
Neff, J. C., Baldocchi, D. D., Lovett, G. M., Goulden, M. L., Howarth, R.
W., Valentini, R., Sala, O. E., Aber, J. D., Melillo, J. M., Matson, P. A.,
Schimel, D. S., Ryan, M. G., Houghton, R. A., Cole, J. J., Schlesinger, W.
H., Running, S. W., Heimann, M., Mooney, H. A., and Rastetter, E. B.:
Reconciling Carbon-cycle Concepts, Terminology, and Methods, Ecosystems,
9, 1041–1050, https://doi.org/10.1007/s10021-005-0105-7, 2006.
Corbett, D. R., Chanton, J., Burnett, W., Dillon, K., Rutkowski, C., and
Fourqurean, J. W.: Patterns of groundwater discharge into Florida Bay,
Limnol. Oceanogr., 44, 1045–1055, https://doi.org/10.4319/lo.1999.44.4.1045, 1999.
Cyronak, T., Santos, I. R., McMahon, A., and Eyre, B. D.: Carbon cycling
hysteresis in permeable carbonate sands over a diel cycle: Implications for
ocean acidificationn, Limnol. Oceanogr., 58, 131–143,
https://doi.org/10.4319/lo.2013.58.1.0131, 2013.
Cyronak, T., Andersson, A. J., D'Angelo, S., Bresnahan, P. J., Davidson, C.
C. C., Griffin, A., Kindeberg, T., Pennise, J., Takeshita, Y., and White,
M.: Short-Term Spatial and Temporal Carbonate Chemistry Variability in Two
Contrasting Seagrass Meadows: Implications for pH Buffering Capacities,
Estuar. Coasts, 5, 1–15, https://doi.org/10.1007/s12237-017-0356-5, 2018.
Deines, P.: The isotopic composition of reduced organic carbon, in: Handbook of Environmental Isotope Geochemistry,
vol. 1, edited by: Fritz, P.
and Fontes, J. C., Elsevier, New York, pp. 329–406, 1980.
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.
Dickson, A. G., Afghan, J. D., and Anderson, G. C.: Reference materials for
oceanic CO2 analysis: a method for the certification of total alkalinity,
Marine Chem., 80, 185–197, 2003.
Dickson, A. G., Sabine, C. L., and Christian, J. R.: Guide to Best Practices for
Ocean CO2 Measurements, PICES Special Publication, 3, 2007.
Duarte, C. M., Middelburg, J. J., and Caraco, N.: Major role of marine vegetation on the oceanic carbon cycle, Biogeosciences, 2, 1–8, https://doi.org/10.5194/bg-2-1-2005, 2005.
Duarte, C. M., Marbà, N., Gacia, E., Fourqurean, J. W., Beggins, J.,
Barrón, C., and Apostolaki, E. T.: Seagrass community metabolism:
Assessing the carbon sink capacity of seagrass meadows, Global Biogeochem.
Cycles, 24, 1–8, https://doi.org/10.1029/2010GB003793, 2010.
DuFore, C. M.: Spatial and Temporal Variations in the Air-Sea Carbon Dioxide
Fluxes of Florida Bay, dissertation, University of South Florida, Tampa, FL,
2012.
Enríquez, S. and Schubert, N.: Direct contribution of the seagrass
Thalassia testudinum to lime mud production, Nat. Commun., 5, 1–12,
https://doi.org/10.1038/ncomms4835, 2014.
Eyre, B. D. and Ferguson, A. J. P.: Comparison of carbon production and
decomposition, benthic nutrient fluxes and denitrification in seagrass,
phytoplankton, benthic microalgae- and macroalgae-dominated warm-temperate
Australian lagoons, Mar. Ecol. Prog. Ser., 229, 43–59,
https://doi.org/10.3354/meps229043, 2002.
Fourqurean, J., Zieman, J., and Powell, G.: Phosphorus limitation of primary
production in Florida Bay: Evidence from
Fourqurean, J. W., Escoria, S. P., Anderson, W. T., and Zieman, J. C.:
Spatial and Seasonal Variability in Elemental Content, δ13C, and
δ15N of Thalassia testudinum from South Florida and Its Implications
for Ecosystem Studies, Estuaries, 28, 447–461, 2005.
Fourqurean, J. W., Duarte, C. M., Kennedy, H., Marbà, N., Holmer, M.,
Mateo, M. A., Apostolaki, E. T., Kendrick, G. A., Krause-Jensen, D.,
McGlathery, K. J., and Serrano, O.: Seagrass ecosystems as a globally
significant carbon stock, Nat. Geosci., 5, 505–509,
https://doi.org/10.1038/ngeo1477, 2012a.
Fourqurean, J. W., Kendrick, G. A., Collins, L. S., Chambers, R. M., and
Vanderklift, M. A.: Carbon, nitrogen and phosphorus storage in subtropical
seagrass meadows: Examples from Florida Bay and Shark Bay, Mar. Freshw.
Res., 63, 967–983, https://doi.org/10.1071/MF12101, 2012b.
Fourqurean, J. W., Manuel, S. A., Coates, K. A., Kenworthy, W. J., and Boyer, J. N.: Water quality, isoscapes and stoichioscapes of seagrasses indicate general P limitation and unique N cycling in shallow water benthos of Bermuda, Biogeosciences, 12, 6235–6249, https://doi.org/10.5194/bg-12-6235-2015, 2015.
Frankovich, T. A. and Zieman, J. C.: Total epiphyte and epiphytic carbonate
production on Thalassia testudinum across Florida Bay, Bull. Mar. Sci.,
54, 679–695, 1994.
Ganguly, D., Singh, G., Ramachandran, P., Selvam, A. P., Banerjee, K., and
Ramachandran, R.: Seagrass metabolism and carbon dynamics in a tropical
coastal embayment, Ambio, 46, 667–679, https://doi.org/10.1007/s13280-017-0916-8,
2017.
Hendriks, I. E., Olsen, Y. S., Ramajo, L., Basso, L., Steckbauer, A., Moore, T. S., Howard, J., and Duarte, C. M.: Photosynthetic activity buffers ocean acidification in seagrass meadows, Biogeosciences, 11, 333–346, https://doi.org/10.5194/bg-11-333-2014, 2014.
Hines, M. and Lyons, W.: Biogeochemistry of Nearshore Bermuda Sediments. I.
Sulfate Reduction Rates and Nutrient Generation, Mar. Ecol. Prog. Ser.,
8, 87–94, https://doi.org/10.3354/meps008087, 2007
Ho, D. T., Law, C. S., Smith, M. J., Schlosser, P., Harvey, M., and Hill, P.:
Measurements of air-sea gas exchange at high wind speeds in the Southern
Ocean: Implications for global parameterizations, Geophys. Res. Lett.,
33, L16611, https://doi.org/10.1029/2006GL026817, 2006.
Ho, D. T., Coffineau, N., Hickman, B., Chow, N., Koffman, T., and Schlosser, P.: Influence of current velocity and wind speed on air-water gas
exchange in a mangrove estuary, Geophys. Res. Lett., 3813–3821,
https://doi.org/10.1002/2016GL068727,
2016.
Ho, D. T., Ferrón, S., Engel, V. C., Anderson, W. T., Swart, P. K., Price, R. M., and Barbero, L.: Dissolved carbon biogeochemistry and export in mangrove-dominated rivers of the Florida Everglades, Biogeosciences, 14, 2543–2559, https://doi.org/10.5194/bg-14-2543-2017, 2017.
Holmer, M. and Nielsen, S. L.: Sediment sulfur dynamics related to
biomass- density patterns in Zostera marina (eelgrass) beds, Mar. Ecol.
Prog. Ser., 146, 163–171, 1997.
Holmer, M., Andersen, F. O., Nielsen, S. L., and Boschker, H. T. S.: The
importance of mineralization based on sulfate reduction for nutrient
regeneration in tropical seagrass sediments, Aquat. Bot., 71, 1–17,
https://doi.org/10.1016/S0304-3770(01)00170-X, 2001.
Holmer, M., Duarte, C. M., and Marba, N.: Sulfur cycling and seagrass (Posidonia oceanica) status in carbonate sediments, Biogeochemistry, 66, 223–239, 2003.
Hopkinson, C. S. and Smith, E. M.: Estuarine respiration: An overview of benthic, pelagic and whole system respiration, in: Respiration in aquatic ecosystems, edited by: del Giorgio, P. A. and Williams, P., Oxford Univ. Press., 122–146, https://doi.org/10.1093/acprof:oso/9780198527084.003.0008, 2007.
Howard, J. L., Creed, J. C., Aguiar, M. V. P., and Fouqurean, J. W.: CO2
released by carbonate sediment production in some coastal areas may offset
the benefits of seagrass “Blue Carbon” storage, Limnol. Oceanogr., 63,
160–172, https://doi.org/10.1002/lno.10621, 2018.
Jensen, H. S., McGlathery, K., Marino, J. R., and Howarth, R. W.: Forms and
availability of sediment phosphorus in carbonate sand of Bermuda seagrass
beds, Limnol. Oceanogr., 43, 799–810, 1998.
Jensen, H. S., Nielsen, O. I., Koch, M. S., and de Vicente, I.: Phosphorus
release with carbonate dissolution coupled to sulfide oxidation in Florida
Bay seagrass sediments, Limnol. Oceanogr., 54, 1753–1764,
https://doi.org/10.4319/lo.2009.54.5.1753, 2009.
Karlsson, J., Jansson, M., and Jonsson, A.: Respiration of
allochthonous organic carbon in unproductive forest lakes determined by the
Keeling plot method, Limnol. Oceanogr., 52, 603–608, https://doi.org/10.4319/lo.2007.52.2.0603, 2007.
Koweek, D. A., Zimmerman, R. C., Hewett, K. M., Gaylord, B., Giddings, S.
N., Nickols, K. J., Ruesink, J., Stachowicz, J. J., Takeshita, Y., and
Caldeira, K.: Expected limits on the ocean acidi fi cation buffering
potential of a temperate seagrass meadow, Ecol. Appl., 28, 1694–1714,
https://doi.org/10.1002/eap.1771, 2018.
Large, W. and Pond, S.: Open Ocean Momentum Flux Measurements in Moderate
to Strong Winds, J. Phys. Oceanogr., 11, 324–336, 1981.
Lee, R. J. and Saylor, J. R.: The effect of a surfactant monolayer
on oxygen transfer across an air/water interface during mixed convection.
Int. J. Heat Mass Tran., 53, 3405–3413,
https://doi.org/10.1016/j.ijheatmasstransfer.2010.03.037, 2010.
Lewis, E. and Wallace, D. W. R.: Program developed for CO2 system
calculations, Rep. ORNL/CDLAC-105, Carbon Dioxide Inf. and Anal. Cent., Oak
Ridge Natl. Lab., U.S. Dep. of Energy, Oak Ridge, Tenn., 1998.
Long, M., Berg, P., and Falter, J.: Seagrass metabolism across a
productivity gradient using the eddy covariance, Eulerian control volume,
and biomass addition techniques, J. Geophys. Res.-Ocean., 120, 2676–2700,
https://doi.org/10.1002/2014JC010441, 2015a.
Long, M. H., Charette, M. A., Martin, W. R., and Mccorkle, D. C.: Oxygen
metabolism and pH in coastal ecosystems: Eddy Covariance Hydrogen ion and
Oxygen Exchange System (ECHOES), Limnol. Oceanogr. Methods, 13, 438–450,
https://doi.org/10.1002/lom3.10038, 2015b.
MacIntyre, S., Jonsson, A., Jansson, M., Aberg, J., Turney, D. E., and
Miller, S. D.: Buoyancy flux, turbulence, and the gas transfer
coefficient in a stratified lake, Geophys. Res. Lett., 37,
2–6, https://doi.org/10.1029/2010GL044164, 2010.
Manzello, D. P., Enochs, I. C., Melo, N. Gledhill, D. K., and Johns, E. M.:
Ocean acidification refugia of the florida reef tract, PLoS One, 7, 1–10, https://doi.org/10.1371/journal.pone.0041715,
2012.
Mazarrasa, I., Marbà, N., Lovelock, C. E., Serrano, O., Lavery, P. S., Fourqurean, J. W., Kennedy, H., Mateo, M. A., Krause-Jensen, D., Steven, A. D. L., and Duarte, C. M.: Seagrass meadows as a globally significant carbonate reservoir, Biogeosciences, 12, 4993–5003, https://doi.org/10.5194/bg-12-4993-2015, 2015.
McDougall, T. J. and Barker, P. M.: Getting started with TEOS-10 and the
Gibbs Seawater (GSW) Oceanographic Toolbox, 28 pp., SCOR/IAPSO WG127, ISBN
978-0-646-55621-5, 2010.
McKenna, S. P. and McGillis, W. R.: The role of free-surface
turbulence and surfactants in air-water gas transfer, Int. J. Heat Mass Tran., 47, 539–553,
https://doi.org/10.1016/j.ijheatmasstransfer.2003.06.001, 2004.
McMahon, A., Santos, I. R., Schulz, K. G., Cyronak, T., and Maher, D. T.: Determining coral reef calcification and primary production using
automated alkalinity, pH and pCO2 measurements at high temporal resolution.
Estuarine, Coast. Shelf Sci., 209, 80–88, https://doi.org/10.1016/j.ecss.2018.04.041,
2018.
Mehrbach, C., Culberson, C. H., Hawley, J. E., and Pytkowicz, R. M.:
Measurement of the apparent dissociation constants of carbonic acid in
seawater at atmospheric pressure, Limnol. Oceanogr., 18, 897–907,
https://doi.org/10.4319/lo.1973.18.6.0897, 1973.
Middelburg, J. J.: Marine Carbon Biogeochemistry, Springer Briefs in Earth
System Sciences, 1, https://doi.org/10.1007/978-3-030-10822-9_1,
2019.
Millero, F., Hiscock, W., Huang, R., Roche, M., and Zhang, J.: Seasonal Variation of the
Carbonate System in Florida Bay, Bull. Mar. Sci., 68, 101–123, 2001.
Nixon, S. W., Oviatt, C. A., Garber, J., and Lee, V.: Diel Metabolism and Nutrient Dynamics in a Salt Marsh Embayment, Ecology, 57, 740–750, 1976.
Odum, H. T. and Hoskin, C. M.: Comparative studies on the metabolism of
marine waters, Publ. Inst. Mar. Sci., Univ. Tex., Texas, 1958.
Pacella, S. R., Brown, C. A., Waldbusser, G. G., Labiosa, R. G., and Hales,
B.: Seagrass habitat metabolism increases short-term extremes and long-term
offset of CO2 under future ocean acidification, P. Natl. Acad. Sci. USA, 115, 1–6,
https://doi.org/10.23719/1407616, 2018.
Perez, D. I., Phinn, S. R., Roelfsema, C. M., Shaw, E., Johnston, L., and
Iguel, J.: Primary Production and Calcification Rates of Algae-Dominated
Reef Flat and Seagrass Communities, J. Geophys. Res.-Biogeo., 123,
2362–2375, https://doi.org/10.1029/2017JG004241, 2018.
Podgrajsek, E., Sahleìe, E., and Rutgersson, A.: Diel cycle of
lake-air CO2 flux from a shallow lake and the impact of waterside convection
on the transfer velocity, J. Geophys. Res.-Biogeo.,
119, 487–507, https://doi.org/10.1002/2014JG002781, 2014.
Raymond, P. A. and Cole, J. J.: Gas Exchange in Rivers and Estuaries:
Choosing a Gas Transfer Velocity, Estuaries, 24, 312–317, 2001.
Röhr, M. E., Holmer, M., Baum, J. K., Björk, M., Chin, D.,
Chalifour, L., Cimon, S., Cusson, M., Dahl, M., and Deyanova, D.: Blue Carbon
Storage Capacity of Temperate Eelgrass (Zostera marina) Meadows, Glob.
Biochem. Cycles, 1457–1475, https://doi.org/10.1029/2018GB005941, 2018.
Ruiz-Halpern, S., Macko, S. A., and Fourqurean, J. W.: The effects of
manipulation of sedimentary iron and organic matter on sediment
biogeochemistry and seagrasses in a subtropical carbonate environment,
Biogeochemistry, 87, 113–126, https://doi.org/10.1007/s10533-007-9162-7, 2008.
Saderne, V., Geraldi, N. R., Macreadie, P. I., Maher, D. T., Middelburg, J.
J., Serrano, O., Almahasheer, H., Arias-Ortiz, A., Cusack, M., Eyre, B. D.,
Fourqurean, J. W., Kennedy, H., Krause-Jensen, D., Kuwae, T., Lavery, P. S.,
Lovelock, C. E., Marba, N., Masqué, P., Mateo, M. A., Mazarrasa, I.,
McGlathery, K. J., Oreska, M. P. J., Sanders, C. J., Santos, I. R., Smoak,
J. M., Tanaya, T., Watanabe, K., and Duarte, C. M.: Role of carbonate burial
in Blue Carbon budgets, Nat. Commun., 120, 29–38, https://doi.org/10.1038/s41467-019-08842-6,
2019.
Shaw, E. C., McNeil, B. I., and Tilbrook, B.: Impacts of ocean
acidification in naturally variable coral reef flat ecosystems, J.
Geophys. Res.-Oceans, 117, C3, https://doi.org/10.1029/2011jc007655, 2012.
Smith, A. C., Kostka, J. E., Devereux, R., and Yates, D. F.: Seasonal composition and activity of sulfate-reducing prokaryotic communities in seagrass bed sediments, Aquat. Microb. Ecol., 37, 183–195, https://doi.org/10.3354/ame037183, 2004.
Smith, S.: Physical, chemical and biological characteristics of CO2
gas flux across the air-water interface, Plant Cell Environ., 8,
387–398, 1985.
Stockman, K. W., Ginsburg, R. N., and Shinn, E. A.: The Production of Lime
Mud by Algae in South Florida, J. Sediment Petrol., 37, 633–648, 1967.
Turk, D., Yates, K. K., Esperance, C. L., Melo, N., Ramsewak, D., Dowd, M.,
Estrada, S. C., Herwitz, S. R., McGillis, W. R., Vega-Rodriguez, M.,
Toro-Farmer, G., L'Esperance, C., Melo, N., Ramsewak, D., Dowd, M., Estrada,
S. C., Muller-Karger, F. E., Herwitz, S. R., and McGillis, W. R.: Community
metabolism in shallow coral reef and seagrass ecosystems, lower Florida
Keys, Mar. Ecol. Prog. Ser., 538, 35–52, https://doi.org/10.3354/meps11385, 2015.
Unsworth, R. K. F., Collier, C. J., Henderson, G. M., and McKenzie, L. J.:
Tropical seagrass meadows modify seawater carbon chemistry: Implications for
coral reefs impacted by ocean acidification, Environ. Res. Lett., 7, 2,
https://doi.org/10.1088/1748-9326/7/2/024026, 2012.
Upstill-Goddard, R. C.: Air–sea gas exchange in the coastal zone, Estuar.
Coast. Shelf Sci., 70, 388–404, https://doi.org/10.1016/j.ecss.2006.05.043, 2006.
Van Dam, B.: Florida Bay Diel, figshare, https://doi.org/10.6084/m9.figshare.7707029, 2019.
Wanless, H. R. and Tagett, M. G.: Origin , Growth and Evolution of
Carbonate Mudbanks in Florida Bay, Bull. Mar. Sci., 44, 454–489, 1989.
Wanninkhof, R. H.: Relationship Between Wind Speed and Gas Exchange, J.
Geophys. Res., 97, 7373–7382, https://doi.org/10.1029/92JC00188, 1992.
Weiss, R. F.: Solubility of nitrogen, oxygen, and argon in water and
seawater, Deep-Sea Res., 17, 721–735, 1970.
Weiss, R. F.: Carbon Dioxide in Water and Seawater: The Solubility of a
Non-ideal Gas, Mar. Chem., 2, 203–215, 1974.
Welsh, D., Castadelli, G., Bartoli, M., Poli, D., Careri, M., De Wit, R., and Viaroli, P.: Denitrification in an intertidal seagrass meadow, a comparison of 15N-isotope and acetylene-block techniques: Dissimilatory nitrate reduction to ammonia as a source of N2O?, Mar. Biol., 139, 1029–1036, https://doi.org/10.1007/s002270100672, 2001.
Yamamoto, S., Kayanne, H., Tokoro, T., Kuwae, T., and Watanabe, A.: Total
alkalinity flux in coral reefs estimated from eddy covariance and sediment
pore-water profiles, Limnol. Oceanogr., 60, 229–241,
https://doi.org/10.1002/lno.10018, 2015.
Yates, K. K. and Halley, R. B.: Diurnal variation in rates of calcification
and carbonate sediment dissolution in Florida Bay, Estuar. Coasts,
29, 24–39, https://doi.org/10.1007/BF02784696, 2006.
Yates, K. K., Dufore, C., Smiley, N., Jackson, C., and Halley, R. B.:
Diurnal variation of oxygen and carbonate system parameters in Tampa Bay and
Florida Bay, Mar. Chem., 104, 110–124,
https://doi.org/10.1016/j.marchem.2006.12.008, 2007.
Zhang, J.-Z. and Fischer, C. J.: Carbon Dynamics of Florida Bay:
Spatiotemporal Patterns and Biological Control, Environ. Sci. Technol.,
48, 9161–9169, https://doi.org/10.1021/es500510z, 2014.
Ziegler, S. and Benner, R.: Ecosystem metabolism in a subtropical, seagrass-dominated lagoon, Mar. Ecol. Prog. Ser., 173, 1–12, https://doi.org/10.3354/meps173001, 1998.
Zieman, J. C., Fourqurean, J. W., and Iverson, R. L.: Distribution,
Abundance and Productivity of Seagrasses and Macroalgae in Florida Bay,
Bull. Mar. Sci., 44, 292–311, 1989.
Zimmerman, R. C., Hill, V. J., and Gallegos, C. L.: Predicting effects of
ocean warming, acidification, and water quality on Chesapeake region
eelgrass, Limnol. Oceanogr., 60, 1781–1804, https://doi.org/10.1002/lno.10139, 2015.
Short summary
We report on direct measurements of net ecosystem productivity (NEP) and net ecosystem calcification (NEC) in a Florida Bay seagrass ecosystem. We found notable differences between our carbon-based NEP and similar determinations made using oxygen. Over the study period, both NEP and NEC were negative, revealing that these sites are net heterotrophic and have dissolved CaCO3. Our findings point to sediments maintaining negative NEP and NEC despite high seagrass above-ground primary production.
We report on direct measurements of net ecosystem productivity (NEP) and net ecosystem...
Altmetrics
Final-revised paper
Preprint