Articles | Volume 19, issue 24
https://doi.org/10.5194/bg-19-5893-2022
© Author(s) 2022. 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-19-5893-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
21 Dec 2022
Research article |
| 21 Dec 2022
| 21 Dec 2022
Role of phosphorus in the seasonal deoxygenation of the East China Sea shelf
Department of Oceanography, Dalhousie University, Halifax, Nova
Scotia, Canada
Haiyan Zhang
Department of Oceanography, Dalhousie University, Halifax, Nova
Scotia, Canada
School of Marine Science and Technology, Tianjin University, Tianjin,
China
Katja Fennel
Department of Oceanography, Dalhousie University, Halifax, Nova
Scotia, Canada
Related authors
Kyoko Ohashi, Arnaud Laurent, Christoph Renkl, Jinyu Sheng, Katja Fennel, and Eric Oliver
EGUsphere, https://doi.org/10.5194/egusphere-2024-1372, https://doi.org/10.5194/egusphere-2024-1372, 2024
Short summary
Short summary
We developed a modelling system of the northwest Atlantic Ocean that simulates the currents, temperature, salinity, and parts of the biochemical cycle of the ocean, as well as sea ice. The system combines advanced, open-source models and can be used to study, for example, the oceans’ capture of atmospheric carbon dioxide which is a key process in the global climate. The system produces realistic results, and we use it to investigate the roles of tides and sea ice in the northwest Atlantic Ocean.
Katja Fennel, Matthew C. Long, Christopher Algar, Brendan Carter, David Keller, Arnaud Laurent, Jann Paul Mattern, Ruth Musgrave, Andreas Oschlies, Josiane Ostiguy, Jaime B. Palter, and Daniel B. Whitt
State Planet, 2-oae2023, 9, https://doi.org/10.5194/sp-2-oae2023-9-2023, https://doi.org/10.5194/sp-2-oae2023-9-2023, 2023
Short summary
Short summary
This paper describes biogeochemical models and modelling techniques for applications related to ocean alkalinity enhancement (OAE) research. Many of the most pressing OAE-related research questions cannot be addressed by observation alone but will require a combination of skilful models and observations. We present illustrative examples with references to further information; describe limitations, caveats, and future research needs; and provide practical recommendations.
Arnaud Laurent, Katja Fennel, and Angela Kuhn
Biogeosciences, 18, 1803–1822, https://doi.org/10.5194/bg-18-1803-2021, https://doi.org/10.5194/bg-18-1803-2021, 2021
Short summary
Short summary
CMIP5 and CMIP6 models, and a high-resolution regional model, were evaluated by comparing historical simulations with observations in the northwest North Atlantic, a climate-sensitive and biologically productive ocean margin region. Many of the CMIP models performed poorly for biological properties. There is no clear link between model resolution and skill in the global models, but there is an overall improvement in performance in CMIP6 from CMIP5. The regional model performed best.
Haiyan Zhang, Katja Fennel, Arnaud Laurent, and Changwei Bian
Biogeosciences, 17, 5745–5761, https://doi.org/10.5194/bg-17-5745-2020, https://doi.org/10.5194/bg-17-5745-2020, 2020
Short summary
Short summary
In coastal seas, low oxygen, which is detrimental to coastal ecosystems, is increasingly caused by man-made nutrients from land. This is especially so near mouths of major rivers, including the Changjiang in the East China Sea. Here a simulation model is used to identify the main factors determining low-oxygen conditions in the region. High river discharge is identified as the prime cause, while wind and intrusions of open-ocean water modulate the severity and extent of low-oxygen conditions.
Fabian Große, Katja Fennel, Haiyan Zhang, and Arnaud Laurent
Biogeosciences, 17, 2701–2714, https://doi.org/10.5194/bg-17-2701-2020, https://doi.org/10.5194/bg-17-2701-2020, 2020
Short summary
Short summary
In the East China Sea, hypoxia occurs frequently from spring to fall due to high primary production and subsequent decomposition of organic matter. Nitrogen inputs from the Changjiang and the open ocean have been suggested to contribute to hypoxia formation. We used a numerical modelling approach to quantify the relative contributions of these nitrogen sources. We found that the Changjiang dominates, which suggests that nitrogen management in the watershed would improve oxygen conditions.
Liuqian Yu, Katja Fennel, Bin Wang, Arnaud Laurent, Keith R. Thompson, and Lynn K. Shay
Ocean Sci., 15, 1801–1814, https://doi.org/10.5194/os-15-1801-2019, https://doi.org/10.5194/os-15-1801-2019, 2019
Short summary
Short summary
We present a first direct comparison of nonidentical versus identical twin approaches for an ocean data assimilation system. We show that the identical twin approach overestimates the value of assimilating satellite observations and undervalues the benefit of assimilating temperature and salinity profiles. Misleading assessments such as undervaluing the impact of observational assets are problematic and can lead to misguided decisions on balancing investments among different observing assets.
Katja Fennel and Arnaud Laurent
Biogeosciences, 15, 3121–3131, https://doi.org/10.5194/bg-15-3121-2018, https://doi.org/10.5194/bg-15-3121-2018, 2018
Short summary
Short summary
Increasing human-derived nutrient inputs to coastal oceans lead to spreading dead zones around the world. Here a biogeochemical model for the northern Gulf of Mexico, where nutrients from the Mississippi River create the largest dead zone in North American coastal waters, is used for the first time to show the effects of single and dual nutrient reductions of nitrogen (N) and phosphorus (P). Significant reductions in N or N&P load would be required to significantly reduce hypoxia in this system.
A. Laurent, K. Fennel, R. Wilson, J. Lehrter, and R. Devereux
Biogeosciences, 13, 77–94, https://doi.org/10.5194/bg-13-77-2016, https://doi.org/10.5194/bg-13-77-2016, 2016
Short summary
Short summary
In low oxygen environments, the lack of oxygen influences sediment biogeochemistry and in turn sediment-water fluxes. These nonlinear interactions are often missing from biogeochemical circulation models because sediment models are computationally expensive. A method for parameterizing realistic sediment-water fluxes is presented and applied to the Mississippi River Dead Zone where high primary production, stimulated by excess nutrient loads, promotes low bottom water conditions in summer.
L. Yu, K. Fennel, A. Laurent, M. C. Murrell, and J. C. Lehrter
Biogeosciences, 12, 2063–2076, https://doi.org/10.5194/bg-12-2063-2015, https://doi.org/10.5194/bg-12-2063-2015, 2015
Short summary
Short summary
Our study suggests that a combination of physical processes and sediment oxygen consumption determine the spatial extent and temporal dynamics of hypoxia on the Louisiana shelf. In summer, stratification isolates oxygen-rich surface waters from hypoxic bottom waters; oxygen outgasses to the atmosphere at this time. A large fraction of primary production occurs below the pycnocline in summer, but this primary production does not strongly affect the spatial extent of hypoxic bottom waters.
Gianpiero Cossarini, Andy Moore, Stefano Ciavatta, and Katja Fennel
State Planet Discuss., https://doi.org/10.5194/sp-2024-8, https://doi.org/10.5194/sp-2024-8, 2024
Preprint under review for SP
Short summary
Short summary
Marine biogeochemistry refers to the cycling of chemical elements resulting from physical transport, chemical reaction, uptake, and processing by living organisms. Biogeochemical models can have a wide range of complexity, from single parameterizations of processes to fully explicit representations of several nutrients, trophic levels, and functional groups. Uncertainty sources are the lack of knowledge about the parameterizations, initial and boundary conditions and the lack of observations
Kyoko Ohashi, Arnaud Laurent, Christoph Renkl, Jinyu Sheng, Katja Fennel, and Eric Oliver
EGUsphere, https://doi.org/10.5194/egusphere-2024-1372, https://doi.org/10.5194/egusphere-2024-1372, 2024
Short summary
Short summary
We developed a modelling system of the northwest Atlantic Ocean that simulates the currents, temperature, salinity, and parts of the biochemical cycle of the ocean, as well as sea ice. The system combines advanced, open-source models and can be used to study, for example, the oceans’ capture of atmospheric carbon dioxide which is a key process in the global climate. The system produces realistic results, and we use it to investigate the roles of tides and sea ice in the northwest Atlantic Ocean.
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
Short summary
Short summary
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.
Robert W. Izett, Katja Fennel, Adam C. Stoer, and David P. Nicholson
Biogeosciences, 21, 13–47, https://doi.org/10.5194/bg-21-13-2024, https://doi.org/10.5194/bg-21-13-2024, 2024
Short summary
Short summary
This paper provides an overview of the capacity to expand the global coverage of marine primary production estimates using autonomous ocean-going instruments, called Biogeochemical-Argo floats. We review existing approaches to quantifying primary production using floats, provide examples of the current implementation of the methods, and offer insights into how they can be better exploited. This paper is timely, given the ongoing expansion of the Biogeochemical-Argo array.
Li-Qing Jiang, Adam V. Subhas, Daniela Basso, Katja Fennel, and Jean-Pierre Gattuso
State Planet, 2-oae2023, 13, https://doi.org/10.5194/sp-2-oae2023-13-2023, https://doi.org/10.5194/sp-2-oae2023-13-2023, 2023
Short summary
Short summary
This paper provides comprehensive guidelines for ocean alkalinity enhancement (OAE) researchers on archiving their metadata and data. It includes data standards for various OAE studies and a universal metadata template. Controlled vocabularies for terms like alkalinization methods are included. These guidelines also apply to ocean acidification data.
Katja Fennel, Matthew C. Long, Christopher Algar, Brendan Carter, David Keller, Arnaud Laurent, Jann Paul Mattern, Ruth Musgrave, Andreas Oschlies, Josiane Ostiguy, Jaime B. Palter, and Daniel B. Whitt
State Planet, 2-oae2023, 9, https://doi.org/10.5194/sp-2-oae2023-9-2023, https://doi.org/10.5194/sp-2-oae2023-9-2023, 2023
Short summary
Short summary
This paper describes biogeochemical models and modelling techniques for applications related to ocean alkalinity enhancement (OAE) research. Many of the most pressing OAE-related research questions cannot be addressed by observation alone but will require a combination of skilful models and observations. We present illustrative examples with references to further information; describe limitations, caveats, and future research needs; and provide practical recommendations.
Stefania A. Ciliberti, Enrique Alvarez Fanjul, Jay Pearlman, Kirsten Wilmer-Becker, Pierre Bahurel, Fabrice Ardhuin, Alain Arnaud, Mike Bell, Segolene Berthou, Laurent Bertino, Arthur Capet, Eric Chassignet, Stefano Ciavatta, Mauro Cirano, Emanuela Clementi, Gianpiero Cossarini, Gianpaolo Coro, Stuart Corney, Fraser Davidson, Marie Drevillon, Yann Drillet, Renaud Dussurget, Ghada El Serafy, Katja Fennel, Marcos Garcia Sotillo, Patrick Heimbach, Fabrice Hernandez, Patrick Hogan, Ibrahim Hoteit, Sudheer Joseph, Simon Josey, Pierre-Yves Le Traon, Simone Libralato, Marco Mancini, Pascal Matte, Angelique Melet, Yasumasa Miyazawa, Andrew M. Moore, Antonio Novellino, Andrew Porter, Heather Regan, Laia Romero, Andreas Schiller, John Siddorn, Joanna Staneva, Cecile Thomas-Courcoux, Marina Tonani, Jose Maria Garcia-Valdecasas, Jennifer Veitch, Karina von Schuckmann, Liying Wan, John Wilkin, and Romane Zufic
State Planet, 1-osr7, 2, https://doi.org/10.5194/sp-1-osr7-2-2023, https://doi.org/10.5194/sp-1-osr7-2-2023, 2023
Benjamin Richaud, Katja Fennel, Eric C. J. Oliver, Michael D. DeGrandpre, Timothée Bourgeois, Xianmin Hu, and Youyu Lu
The Cryosphere, 17, 2665–2680, https://doi.org/10.5194/tc-17-2665-2023, https://doi.org/10.5194/tc-17-2665-2023, 2023
Short summary
Short summary
Sea ice is a dynamic carbon reservoir. Its seasonal growth and melt modify the carbonate chemistry in the upper ocean, with consequences for the Arctic Ocean carbon sink. Yet, the importance of this process is poorly quantified. Using two independent approaches, this study provides new methods to evaluate the error in air–sea carbon flux estimates due to the lack of biogeochemistry in ice in earth system models. Those errors range from 5 % to 30 %, depending on the model and climate projection.
Krysten Rutherford, Katja Fennel, Dariia Atamanchuk, Douglas Wallace, and Helmuth Thomas
Biogeosciences, 18, 6271–6286, https://doi.org/10.5194/bg-18-6271-2021, https://doi.org/10.5194/bg-18-6271-2021, 2021
Short summary
Short summary
Using a regional model of the northwestern North Atlantic shelves in combination with a surface water time series and repeat transect observations, we investigate surface CO2 variability on the Scotian Shelf. The study highlights a strong seasonal cycle in shelf-wide pCO2 and spatial variability throughout the summer months driven by physical events. The simulated net flux of CO2 on the Scotian Shelf is out of the ocean, deviating from the global air–sea CO2 flux trend in continental shelves.
Bin Wang, Katja Fennel, and Liuqian Yu
Ocean Sci., 17, 1141–1156, https://doi.org/10.5194/os-17-1141-2021, https://doi.org/10.5194/os-17-1141-2021, 2021
Short summary
Short summary
We demonstrate that even sparse BGC-Argo profiles can substantially improve biogeochemical prediction via a priori model tuning. By assimilating satellite surface chlorophyll and physical observations, subsurface distributions of physical properties and nutrients were improved immediately. The improvement of subsurface chlorophyll was modest initially but was greatly enhanced after adjusting the parameterization for light attenuation through further a priori tuning.
Thomas S. Bianchi, Madhur Anand, Chris T. Bauch, Donald E. Canfield, Luc De Meester, Katja Fennel, Peter M. Groffman, Michael L. Pace, Mak Saito, and Myrna J. Simpson
Biogeosciences, 18, 3005–3013, https://doi.org/10.5194/bg-18-3005-2021, https://doi.org/10.5194/bg-18-3005-2021, 2021
Short summary
Short summary
Better development of interdisciplinary ties between biology, geology, and chemistry advances biogeochemistry through (1) better integration of contemporary (or rapid) evolutionary adaptation to predict changing biogeochemical cycles and (2) universal integration of data from long-term monitoring sites in terrestrial, aquatic, and human systems that span broad geographical regions for use in modeling.
Arnaud Laurent, Katja Fennel, and Angela Kuhn
Biogeosciences, 18, 1803–1822, https://doi.org/10.5194/bg-18-1803-2021, https://doi.org/10.5194/bg-18-1803-2021, 2021
Short summary
Short summary
CMIP5 and CMIP6 models, and a high-resolution regional model, were evaluated by comparing historical simulations with observations in the northwest North Atlantic, a climate-sensitive and biologically productive ocean margin region. Many of the CMIP models performed poorly for biological properties. There is no clear link between model resolution and skill in the global models, but there is an overall improvement in performance in CMIP6 from CMIP5. The regional model performed best.
Haiyan Zhang, Katja Fennel, Arnaud Laurent, and Changwei Bian
Biogeosciences, 17, 5745–5761, https://doi.org/10.5194/bg-17-5745-2020, https://doi.org/10.5194/bg-17-5745-2020, 2020
Short summary
Short summary
In coastal seas, low oxygen, which is detrimental to coastal ecosystems, is increasingly caused by man-made nutrients from land. This is especially so near mouths of major rivers, including the Changjiang in the East China Sea. Here a simulation model is used to identify the main factors determining low-oxygen conditions in the region. High river discharge is identified as the prime cause, while wind and intrusions of open-ocean water modulate the severity and extent of low-oxygen conditions.
Christopher Gordon, Katja Fennel, Clark Richards, Lynn K. Shay, and Jodi K. Brewster
Biogeosciences, 17, 4119–4134, https://doi.org/10.5194/bg-17-4119-2020, https://doi.org/10.5194/bg-17-4119-2020, 2020
Short summary
Short summary
We describe a method for correcting errors in oxygen optode measurements on autonomous platforms in the ocean. The errors result from the relatively slow response time of the sensor. The correction method includes an in situ determination of the effective response time and requires the time stamps of the individual measurements. It is highly relevant for the BGC-Argo program and also applicable to gliders. We also explore if diurnal changes in oxygen can be obtained from profiling floats.
Bin Wang, Katja Fennel, Liuqian Yu, and Christopher Gordon
Biogeosciences, 17, 4059–4074, https://doi.org/10.5194/bg-17-4059-2020, https://doi.org/10.5194/bg-17-4059-2020, 2020
Short summary
Short summary
We assess trade-offs between different types of biological observations, specifically satellite ocean color and BGC-Argo profiles and the benefits of combining both for optimizing a biogeochemical model of the Gulf of Mexico. Using all available observations leads to significant improvements in observed and unobserved variables (including primary production and C export). Our results highlight the significant benefits of BGC-Argo measurements for biogeochemical model optimization and validation.
Fabian Große, Katja Fennel, Haiyan Zhang, and Arnaud Laurent
Biogeosciences, 17, 2701–2714, https://doi.org/10.5194/bg-17-2701-2020, https://doi.org/10.5194/bg-17-2701-2020, 2020
Short summary
Short summary
In the East China Sea, hypoxia occurs frequently from spring to fall due to high primary production and subsequent decomposition of organic matter. Nitrogen inputs from the Changjiang and the open ocean have been suggested to contribute to hypoxia formation. We used a numerical modelling approach to quantify the relative contributions of these nitrogen sources. We found that the Changjiang dominates, which suggests that nitrogen management in the watershed would improve oxygen conditions.
Liuqian Yu, Katja Fennel, Bin Wang, Arnaud Laurent, Keith R. Thompson, and Lynn K. Shay
Ocean Sci., 15, 1801–1814, https://doi.org/10.5194/os-15-1801-2019, https://doi.org/10.5194/os-15-1801-2019, 2019
Short summary
Short summary
We present a first direct comparison of nonidentical versus identical twin approaches for an ocean data assimilation system. We show that the identical twin approach overestimates the value of assimilating satellite observations and undervalues the benefit of assimilating temperature and salinity profiles. Misleading assessments such as undervaluing the impact of observational assets are problematic and can lead to misguided decisions on balancing investments among different observing assets.
Katja Fennel, Simone Alin, Leticia Barbero, Wiley Evans, Timothée Bourgeois, Sarah Cooley, John Dunne, Richard A. Feely, Jose Martin Hernandez-Ayon, Xinping Hu, Steven Lohrenz, Frank Muller-Karger, Raymond Najjar, Lisa Robbins, Elizabeth Shadwick, Samantha Siedlecki, Nadja Steiner, Adrienne Sutton, Daniela Turk, Penny Vlahos, and Zhaohui Aleck Wang
Biogeosciences, 16, 1281–1304, https://doi.org/10.5194/bg-16-1281-2019, https://doi.org/10.5194/bg-16-1281-2019, 2019
Short summary
Short summary
We review and synthesize available information on coastal ocean carbon fluxes around North America (NA). There is overwhelming evidence, compiled and discussed here, that the NA coastal margins act as a sink. Our synthesis shows the great diversity in processes driving carbon fluxes in different coastal regions, highlights remaining gaps in observations and models, and discusses current and anticipated future trends with respect to carbon fluxes and acidification.
Angela M. Kuhn, Katja Fennel, and Ilana Berman-Frank
Biogeosciences, 15, 7379–7401, https://doi.org/10.5194/bg-15-7379-2018, https://doi.org/10.5194/bg-15-7379-2018, 2018
Short summary
Short summary
Recent studies demonstrate that marine N2 fixation can be carried out without light. However, direct measurements of N2 fixation in dark environments are relatively scarce. This study uses a model that represents biogeochemical cycles at a deep-ocean location in the Gulf of Aqaba (Red Sea). Different model versions are used to test assumptions about N2 fixers. Relaxing light limitation for marine N2 fixers improved the similarity between model results and observations of deep nitrate and oxygen.
Krysten Rutherford and Katja Fennel
Ocean Sci., 14, 1207–1221, https://doi.org/10.5194/os-14-1207-2018, https://doi.org/10.5194/os-14-1207-2018, 2018
Short summary
Short summary
Using a regional model of the northwestern North Atlantic shelves, we calculate transport timescales and pathways in order to understand the transport processes that underlie the rapid oxygen loss, air–sea CO2 flux, and supply of plankton seed populations on the Scotian Shelf. Study results highlight the limited connectivity between the Scotian Shelf and adjacent slope waters; instead, the dominant southwestward currents bring Grand Banks and Gulf of St. Lawrence waters to the Scotian Shelf.
Katja Fennel and Arnaud Laurent
Biogeosciences, 15, 3121–3131, https://doi.org/10.5194/bg-15-3121-2018, https://doi.org/10.5194/bg-15-3121-2018, 2018
Short summary
Short summary
Increasing human-derived nutrient inputs to coastal oceans lead to spreading dead zones around the world. Here a biogeochemical model for the northern Gulf of Mexico, where nutrients from the Mississippi River create the largest dead zone in North American coastal waters, is used for the first time to show the effects of single and dual nutrient reductions of nitrogen (N) and phosphorus (P). Significant reductions in N or N&P load would be required to significantly reduce hypoxia in this system.
Jonathan Lemay, Helmuth Thomas, Susanne E. Craig, William J. Burt, Katja Fennel, and Blair J. W. Greenan
Biogeosciences, 15, 2111–2123, https://doi.org/10.5194/bg-15-2111-2018, https://doi.org/10.5194/bg-15-2111-2018, 2018
Short summary
Short summary
We report a detailed mechanistic investigation of the impact of Hurricane Arthur on the CO2 cycling on the Scotian Shelf. We can show that in contrast to common thinking, the deepening of the surface during the summer months can lead to increased CO2 uptake as carbon-poor waters from subsurface water are brought up to the surface. Only during prolonged storm events is the deepening of the mixed layer strong enough to bring the (expected) carbon-rich water to the surface.
Julia M. Moriarty, Courtney K. Harris, Katja Fennel, Marjorie A. M. Friedrichs, Kehui Xu, and Christophe Rabouille
Biogeosciences, 14, 1919–1946, https://doi.org/10.5194/bg-14-1919-2017, https://doi.org/10.5194/bg-14-1919-2017, 2017
Short summary
Short summary
In coastal aquatic environments, resuspension of sediment and organic material from the seabed into the overlying water can impact biogeochemistry. Here, we used a novel modeling approach to quantify this impact for the Rhône River delta. In the model, resuspension increased oxygen consumption during individual resuspension events, and when results were averaged over 2 months. This implies that observations and models that only represent calm conditions may underestimate net oxygen consumption.
Zuo Xue, Ruoying He, Katja Fennel, Wei-Jun Cai, Steven Lohrenz, Wei-Jen Huang, Hanqin Tian, Wei Ren, and Zhengchen Zang
Biogeosciences, 13, 4359–4377, https://doi.org/10.5194/bg-13-4359-2016, https://doi.org/10.5194/bg-13-4359-2016, 2016
Short summary
Short summary
In this study we used a state-of-the-science coupled physical–biogeochemical model to simulate and examine temporal and spatial variability of sea surface CO2 concentration in the Gulf of Mexico. Our model revealed the Gulf was a net CO2 sink with a flux of 1.11 ± 0.84 × 1012 mol C yr−1. We also found that biological uptake was the primary driver making the Gulf an overall CO2 sink and that the carbon flux in the northern Gulf was very susceptible to changes in river inputs.
A. Laurent, K. Fennel, R. Wilson, J. Lehrter, and R. Devereux
Biogeosciences, 13, 77–94, https://doi.org/10.5194/bg-13-77-2016, https://doi.org/10.5194/bg-13-77-2016, 2016
Short summary
Short summary
In low oxygen environments, the lack of oxygen influences sediment biogeochemistry and in turn sediment-water fluxes. These nonlinear interactions are often missing from biogeochemical circulation models because sediment models are computationally expensive. A method for parameterizing realistic sediment-water fluxes is presented and applied to the Mississippi River Dead Zone where high primary production, stimulated by excess nutrient loads, promotes low bottom water conditions in summer.
L. Yu, K. Fennel, A. Laurent, M. C. Murrell, and J. C. Lehrter
Biogeosciences, 12, 2063–2076, https://doi.org/10.5194/bg-12-2063-2015, https://doi.org/10.5194/bg-12-2063-2015, 2015
Short summary
Short summary
Our study suggests that a combination of physical processes and sediment oxygen consumption determine the spatial extent and temporal dynamics of hypoxia on the Louisiana shelf. In summer, stratification isolates oxygen-rich surface waters from hypoxic bottom waters; oxygen outgasses to the atmosphere at this time. A large fraction of primary production occurs below the pycnocline in summer, but this primary production does not strongly affect the spatial extent of hypoxic bottom waters.
K.-K. Liu, C.-K. Kang, T. Kobari, H. Liu, C. Rabouille, and K. Fennel
Biogeosciences, 11, 7061–7075, https://doi.org/10.5194/bg-11-7061-2014, https://doi.org/10.5194/bg-11-7061-2014, 2014
Short summary
Short summary
This paper provides background info on the East China Sea, Japan/East Sea and South China Sea and highlights major findings in the special issue on their biogeochemical conditions and ecosystem functions. The three seas are subject to strong impacts from human activities and/or climate forcing. Because these continental margins sustain arguably some of the most productive marine ecosystems in the world, changes in these stressed ecosystems may threaten the livelihood of a large human population.
Z. Xue, R. He, K. Fennel, W.-J. Cai, S. Lohrenz, and C. Hopkinson
Biogeosciences, 10, 7219–7234, https://doi.org/10.5194/bg-10-7219-2013, https://doi.org/10.5194/bg-10-7219-2013, 2013
W. J. Burt, H. Thomas, K. Fennel, and E. Horne
Biogeosciences, 10, 53–66, https://doi.org/10.5194/bg-10-53-2013, https://doi.org/10.5194/bg-10-53-2013, 2013
Related subject area
Biogeochemistry: Coastal Ocean
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
Temperature-enhanced effects of iron on Southern Ocean phytoplankton
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
Reviews and syntheses: Biological Indicators of Oxygen Stress in Water Breathing Animals
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
Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth System Model
Uncertainty in the evolution of northwestern North Atlantic circulation leads to diverging biogeochemical projections
The additionality problem of ocean alkalinity enhancement
Short-term variation in pH in seawaters around coastal areas of Japan: characteristics and forcings
Revisiting the applicability and constraints of molybdenum- and uranium-based paleo redox proxies: comparing two contrasting sill fjords
Influence of a small submarine canyon on biogenic matter export flux in the lower St. Lawrence Estuary, eastern Canada
Single-celled bioturbators: benthic foraminifera mediate oxygen penetration and prokaryotic diversity in intertidal sediment
Assessing impacts of coastal warming, acidification, and deoxygenation on Pacific oyster (Crassostrea gigas) farming: a case study in the Hinase area, Okayama Prefecture, and Shizugawa Bay, Miyagi Prefecture, Japan
Multiple nitrogen sources for primary production inferred from δ13C and δ15N in the southern Sea of Japan
Influence of manganese cycling on alkalinity in the redox stratified water column of Chesapeake Bay
Estuarine flocculation dynamics of organic carbon and metals from boreal acid sulfate soils
Drivers of particle sinking velocities in the Peruvian upwelling system
Impacts and uncertainties of climate-induced changes in watershed inputs on estuarine hypoxia
Considerations for hypothetical carbon dioxide removal via alkalinity addition in the Amazon River watershed
High metabolism and periodic hypoxia associated with drifting macrophyte detritus in the shallow subtidal Baltic Sea
Production and accumulation of reef framework by calcifying corals and macroalgae on a remote Indian Ocean cay
Zooplankton community succession and trophic links during a mesocosm experiment in the coastal upwelling off Callao Bay (Peru)
Temporal and spatial evolution of bottom-water hypoxia in the St Lawrence estuarine system
Significant nutrient consumption in the dark subsurface layer during a diatom bloom: a case study on Funka Bay, Hokkaido, Japan
Contrasts in dissolved, particulate, and sedimentary organic carbon from the Kolyma River to the East Siberian Shelf
Sediment quality assessment in an industrialized Greek coastal marine area (western Saronikos Gulf)
Limits and CO2 equilibration of near-coast alkalinity enhancement
Interannual variability of the initiation of the phytoplankton growing period in two French coastal ecosystems
Spatio-temporal distribution, photoreactivity and environmental control of dissolved organic matter in the sea-surface microlayer of the eastern marginal seas of China
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.
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
EGUsphere, https://doi.org/10.5194/egusphere-2024-1508, https://doi.org/10.5194/egusphere-2024-1508, 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 Fe clean shipboard 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.
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.
Michael R. Roman, Andrew H. Altieri, Denise Breitburg, Erica Ferrer, Natalya D. Gallo, Shin-ichi Ito, Karin Limburg, Kenneth Rose, Moriaki Yasuhara, and Lisa A. Levin
EGUsphere, https://doi.org/10.5194/egusphere-2024-616, https://doi.org/10.5194/egusphere-2024-616, 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 oxygen stress for marine animals including their use, research needs and application to confront the challenges of ocean oxygen loss.
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.
Miriam Tivig, David Peter Keller, and Andreas Oschlies
EGUsphere, https://doi.org/10.5194/egusphere-2024-258, https://doi.org/10.5194/egusphere-2024-258, 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 increase primary production rates.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
We carried out parallel year-round observations of pH and related parameters in five stations around the Japan coast. It was found that short-term acidified situations with Omega_ar less than 1.5 occurred at four of five stations. Most of such short-term acidified events were related to the short-term low salinity event, and the extent of short-term pH drawdown at high freshwater input was positively correlated with the nutrient concentration of the main rivers that flow into the coastal area.
K. Mareike Paul, Martijn Hermans, Sami A. Jokinen, Inda Brinkmann, Helena L. Filipsson, and Tom Jilbert
Biogeosciences, 20, 5003–5028, https://doi.org/10.5194/bg-20-5003-2023, https://doi.org/10.5194/bg-20-5003-2023, 2023
Short summary
Short summary
Seawater naturally contains trace metals such as Mo and U, which accumulate under low oxygen conditions on the seafloor. Previous studies have used sediment Mo and U contents as an archive of changing oxygen concentrations in coastal waters. Here we show that in fjords the use of Mo and U for this purpose may be impaired by additional processes. Our findings have implications for the reliable use of Mo and U to reconstruct oxygen changes in fjords.
Hannah Sharpe, Michel Gosselin, Catherine Lalande, Alexandre Normandeau, Jean-Carlos Montero-Serrano, Khouloud Baccara, Daniel Bourgault, Owen Sherwood, and Audrey Limoges
Biogeosciences, 20, 4981–5001, https://doi.org/10.5194/bg-20-4981-2023, https://doi.org/10.5194/bg-20-4981-2023, 2023
Short summary
Short summary
We studied the impact of submarine canyon processes within the Pointe-des-Monts system on biogenic matter export and phytoplankton assemblages. Using data from three oceanographic moorings, we show that the canyon experienced two low-amplitude sediment remobilization events in 2020–2021 that led to enhanced particle fluxes in the deep-water column layer > 2.6 km offshore. Sinking phytoplankton fluxes were lower near the canyon compared to background values from the lower St. Lawrence Estuary.
Dewi Langlet, Florian Mermillod-Blondin, Noémie Deldicq, Arthur Bauville, Gwendoline Duong, Lara Konecny, Mylène Hugoni, Lionel Denis, and Vincent M. P. Bouchet
Biogeosciences, 20, 4875–4891, https://doi.org/10.5194/bg-20-4875-2023, https://doi.org/10.5194/bg-20-4875-2023, 2023
Short summary
Short summary
Benthic foraminifera are single-cell marine organisms which can move in the sediment column. They were previously reported to horizontally and vertically transport sediment particles, yet the impact of their motion on the dissolved fluxes remains unknown. Using microprofiling, we show here that foraminiferal burrow formation increases the oxygen penetration depth in the sediment, leading to a change in the structure of the prokaryotic community.
Masahiko Fujii, Ryuji Hamanoue, Lawrence Patrick Cases Bernardo, Tsuneo Ono, Akihiro Dazai, Shigeyuki Oomoto, Masahide Wakita, and Takehiro Tanaka
Biogeosciences, 20, 4527–4549, https://doi.org/10.5194/bg-20-4527-2023, https://doi.org/10.5194/bg-20-4527-2023, 2023
Short summary
Short summary
This is the first study of the current and future impacts of climate change on Pacific oyster farming in Japan. Future coastal warming and acidification may affect oyster larvae as a result of longer exposure to lower-pH waters. A prolonged spawning period may harm oyster processing by shortening the shipping period and reducing oyster quality. To minimize impacts on Pacific oyster farming, in addition to mitigation measures, local adaptation measures may be required.
Taketoshi Kodama, Atsushi Nishimoto, Ken-ichi Nakamura, Misato Nakae, Naoki Iguchi, Yosuke Igeta, and Yoichi Kogure
Biogeosciences, 20, 3667–3682, https://doi.org/10.5194/bg-20-3667-2023, https://doi.org/10.5194/bg-20-3667-2023, 2023
Short summary
Short summary
Carbon and nitrogen are essential elements for organisms; their stable isotope ratios (13C : 12C, 15N : 14N) are useful tools for understanding turnover and movement in the ocean. In the Sea of Japan, the environment is rapidly being altered by human activities. The 13C : 12C of small organic particles is increased by active carbon fixation, and phytoplankton growth increases the values. The 15N : 14N variations suggest that nitrates from many sources contribute to organic production.
Aubin Thibault de Chanvalon, George W. Luther, Emily R. Estes, Jennifer Necker, Bradley M. Tebo, Jianzhong Su, and Wei-Jun Cai
Biogeosciences, 20, 3053–3071, https://doi.org/10.5194/bg-20-3053-2023, https://doi.org/10.5194/bg-20-3053-2023, 2023
Short summary
Short summary
The intensity of the oceanic trap of CO2 released by anthropogenic activities depends on the alkalinity brought by continental weathering. Between ocean and continent, coastal water and estuaries can limit or favour the alkalinity transfer. This study investigate new interactions between dissolved metals and alkalinity in the oxygen-depleted zone of estuaries.
Joonas J. Virtasalo, Peter Österholm, and Eero Asmala
Biogeosciences, 20, 2883–2901, https://doi.org/10.5194/bg-20-2883-2023, https://doi.org/10.5194/bg-20-2883-2023, 2023
Short summary
Short summary
We mixed acidic metal-rich river water from acid sulfate soils and seawater in the laboratory to study the flocculation of dissolved metals and organic matter in estuaries. Al and Fe flocculated already at a salinity of 0–2 to large organic flocs (>80 µm size). Precipitation of Al and Fe hydroxide flocculi (median size 11 µm) began when pH exceeded ca. 5.5. Mn transferred weakly to Mn hydroxides and Co to the flocs. Up to 50 % of Cu was associated with the flocs, irrespective of seawater mixing.
Moritz Baumann, Allanah Joy Paul, Jan Taucher, Lennart Thomas Bach, Silvan Goldenberg, Paul Stange, Fabrizio Minutolo, and Ulf Riebesell
Biogeosciences, 20, 2595–2612, https://doi.org/10.5194/bg-20-2595-2023, https://doi.org/10.5194/bg-20-2595-2023, 2023
Short summary
Short summary
The sinking velocity of marine particles affects how much atmospheric CO2 is stored inside our oceans. We measured particle sinking velocities in the Peruvian upwelling system and assessed their physical and biochemical drivers. We found that sinking velocity was mainly influenced by particle size and porosity, while ballasting minerals played only a minor role. Our findings help us to better understand the particle sinking dynamics in this highly productive marine system.
Kyle E. Hinson, Marjorie A. M. Friedrichs, Raymond G. Najjar, Maria Herrmann, Zihao Bian, Gopal Bhatt, Pierre St-Laurent, Hanqin Tian, and Gary Shenk
Biogeosciences, 20, 1937–1961, https://doi.org/10.5194/bg-20-1937-2023, https://doi.org/10.5194/bg-20-1937-2023, 2023
Short summary
Short summary
Climate impacts are essential for environmental managers to consider when implementing nutrient reduction plans designed to reduce hypoxia. This work highlights relative sources of uncertainty in modeling regional climate impacts on the Chesapeake Bay watershed and consequent declines in bay oxygen levels. The results demonstrate that planned water quality improvement goals are capable of reducing hypoxia levels by half, offsetting climate-driven impacts on terrestrial runoff.
Linquan Mu, Jaime B. Palter, and Hongjie Wang
Biogeosciences, 20, 1963–1977, https://doi.org/10.5194/bg-20-1963-2023, https://doi.org/10.5194/bg-20-1963-2023, 2023
Short summary
Short summary
Enhancing ocean alkalinity accelerates carbon dioxide removal from the atmosphere. We hypothetically added alkalinity to the Amazon River and examined the increment of the carbon uptake by the Amazon plume. We also investigated the minimum alkalinity addition in which this perturbation at the river mouth could be detected above the natural variability.
Karl M. Attard, Anna Lyssenko, and Iván F. Rodil
Biogeosciences, 20, 1713–1724, https://doi.org/10.5194/bg-20-1713-2023, https://doi.org/10.5194/bg-20-1713-2023, 2023
Short summary
Short summary
Aquatic plants produce a large amount of organic matter through photosynthesis that, following erosion, is deposited on the seafloor. In this study, we show that plant detritus can trigger low-oxygen conditions (hypoxia) in shallow coastal waters, making conditions challenging for most marine animals. We propose that the occurrence of hypoxia may be underestimated because measurements typically do not consider the region closest to the seafloor, where detritus accumulates.
M. James McLaughlin, Cindy Bessey, Gary A. Kendrick, John Keesing, and Ylva S. Olsen
Biogeosciences, 20, 1011–1026, https://doi.org/10.5194/bg-20-1011-2023, https://doi.org/10.5194/bg-20-1011-2023, 2023
Short summary
Short summary
Coral reefs face increasing pressures from environmental change at present. The coral reef framework is produced by corals and calcifying algae. The Kimberley region of Western Australia has escaped land-based anthropogenic impacts. Specimens of the dominant coral and algae were collected from Browse Island's reef platform and incubated in mesocosms to measure calcification and production patterns of oxygen. This study provides important data on reef building and climate-driven effects.
Patricia Ayón Dejo, Elda Luz Pinedo Arteaga, Anna Schukat, Jan Taucher, Rainer Kiko, Helena Hauss, Sabrina Dorschner, Wilhelm Hagen, Mariona Segura-Noguera, and Silke Lischka
Biogeosciences, 20, 945–969, https://doi.org/10.5194/bg-20-945-2023, https://doi.org/10.5194/bg-20-945-2023, 2023
Short summary
Short summary
Ocean upwelling regions are highly productive. With ocean warming, severe changes in upwelling frequency and/or intensity and expansion of accompanying oxygen minimum zones are projected. In a field experiment off Peru, we investigated how different upwelling intensities affect the pelagic food web and found failed reproduction of dominant zooplankton. The changes projected could severely impact the reproductive success of zooplankton communities and the pelagic food web in upwelling regions.
Mathilde Jutras, Alfonso Mucci, Gwenaëlle Chaillou, William A. Nesbitt, and Douglas W. R. Wallace
Biogeosciences, 20, 839–849, https://doi.org/10.5194/bg-20-839-2023, https://doi.org/10.5194/bg-20-839-2023, 2023
Short summary
Short summary
The deep waters of the lower St Lawrence Estuary and gulf have, in the last decades, experienced a strong decline in their oxygen concentration. Below 65 µmol L-1, the waters are said to be hypoxic, with dire consequences for marine life. We show that the extent of the hypoxic zone shows a seven-fold increase in the last 20 years, reaching 9400 km2 in 2021. After a stable period at ~ 65 µmol L⁻¹ from 1984 to 2019, the oxygen level also suddenly decreased to ~ 35 µmol L-1 in 2020.
Sachi Umezawa, Manami Tozawa, Yuichi Nosaka, Daiki Nomura, Hiroji Onishi, Hiroto Abe, Tetsuya Takatsu, and Atsushi Ooki
Biogeosciences, 20, 421–438, https://doi.org/10.5194/bg-20-421-2023, https://doi.org/10.5194/bg-20-421-2023, 2023
Short summary
Short summary
We conducted repetitive observations in Funka Bay, Japan, during the spring bloom 2019. We found nutrient concentration decreases in the dark subsurface layer during the bloom. Incubation experiments confirmed that diatoms could consume nutrients at a substantial rate, even in darkness. We concluded that the nutrient reduction was mainly caused by nutrient consumption by diatoms in the dark.
Dirk Jong, Lisa Bröder, Tommaso Tesi, Kirsi H. Keskitalo, Nikita Zimov, Anna Davydova, Philip Pika, Negar Haghipour, Timothy I. Eglinton, and Jorien E. Vonk
Biogeosciences, 20, 271–294, https://doi.org/10.5194/bg-20-271-2023, https://doi.org/10.5194/bg-20-271-2023, 2023
Short summary
Short summary
With this study, we want to highlight the importance of studying both land and ocean together, and water and sediment together, as these systems function as a continuum, and determine how organic carbon derived from permafrost is broken down and its effect on global warming. Although on the one hand it appears that organic carbon is removed from sediments along the pathway of transport from river to ocean, it also appears to remain relatively ‘fresh’, despite this removal and its very old age.
Georgia Filippi, Manos Dassenakis, Vasiliki Paraskevopoulou, and Konstantinos Lazogiannis
Biogeosciences, 20, 163–189, https://doi.org/10.5194/bg-20-163-2023, https://doi.org/10.5194/bg-20-163-2023, 2023
Short summary
Short summary
The pollution of the western Saronikos Gulf from heavy metals has been examined through the study of marine sediment cores. It is a deep gulf (maximum depth 440 m) near Athens affected by industrial and volcanic activity. Eight cores were received from various stations and depths and analysed for their heavy metal content and geochemical characteristics. The results were evaluated by using statistical methods, environmental indicators and comparisons with old data.
Jing He and Michael D. Tyka
Biogeosciences, 20, 27–43, https://doi.org/10.5194/bg-20-27-2023, https://doi.org/10.5194/bg-20-27-2023, 2023
Short summary
Short summary
Recently, ocean alkalinity enhancement (OAE) has gained interest as a scalable way to address the urgent need for negative CO2 emissions. In this paper we examine the capacity of different coastlines to tolerate alkalinity enhancement and the time scale of CO2 uptake following the addition of a given quantity of alkalinity. The results suggest that OAE has significant potential and identify specific favorable and unfavorable coastlines for its deployment.
Coline Poppeschi, Guillaume Charria, Anne Daniel, Romaric Verney, Peggy Rimmelin-Maury, Michaël Retho, Eric Goberville, Emilie Grossteffan, and Martin Plus
Biogeosciences, 19, 5667–5687, https://doi.org/10.5194/bg-19-5667-2022, https://doi.org/10.5194/bg-19-5667-2022, 2022
Short summary
Short summary
This paper aims to understand interannual changes in the initiation of the phytoplankton growing period (IPGP) in the current context of global climate changes over the last 20 years. An important variability in the timing of the IPGP is observed with a trend towards a later IPGP during this last decade. The role and the impact of extreme events (cold spells, floods, and wind burst) on the IPGP is also detailed.
Lin Yang, Jing Zhang, Anja Engel, and Gui-Peng Yang
Biogeosciences, 19, 5251–5268, https://doi.org/10.5194/bg-19-5251-2022, https://doi.org/10.5194/bg-19-5251-2022, 2022
Short summary
Short summary
Enrichment factors of dissolved organic matter (DOM) in the eastern marginal seas of China exhibited a significant spatio-temporal variation. Photochemical and enrichment processes co-regulated DOM enrichment in the sea-surface microlayer (SML). Autochthonous DOM was more frequently enriched in the SML than terrestrial DOM. DOM in the sub-surface water exhibited higher aromaticity than that in the SML.
Cited articles
Alexander, R. B., Smith, R. A., Schwarz, G. E., Boyer, E. W., Nolan, J. V.,
and Brakebill, J. W.: Differences in Phosphorus and Nitrogen Delivery to The
Gulf of Mexico from the Mississippi River Basin, Environ. Sci. Technol.,
42, 822–830, https://doi.org/10.1021/es0716103, 2008.
Bai, Y., He, X., Pan, D., Chen, C.-T. A., Kang, Y., Chen, X., and Cai, W.-J.:
Summertime Changjiang River plume variation during 1998–2010, J. Geophys.
Res.-Ocean., 119, 6238–6257, https://doi.org/10.1002/2014JC009866, 2014.
Beusen, A. H. W., Bouwman, A. F., Van Beek, L. P. H., Mogollón, J. M.,
and Middelburg, J. J.: Global riverine N and P transport to ocean increased
during the 20th century despite increased retention along the aquatic
continuum, Biogeosciences, 13, 2441–2451, https://doi.org/10.5194/bg-13-2441-2016,
2016.
Bian, C., Jiang, W., and Greatbatch, R. J.: An exploratory model study of
sediment transport sources and deposits in the Bohai Sea, Yellow Sea, and
East China Sea, J. Geophys. Res.-Ocean., 118, 5908–5923,
https://doi.org/10.1002/2013JC009116, 2013.
Boesch, D. F.: Barriers and Bridges in Abating Coastal Eutrophication,
Front. Mar. Sci., 6, 123, https://doi.org/10.3389/fmars.2019.00123, 2019.
Carton, J. A. and Giese, B. S.: A Reanalysis of Ocean Climate Using Simple
Ocean Data Assimilation (SODA), Mon. Weather Rev., 136, 2999–3017,
https://doi.org/10.1175/2007MWR1978.1, 2008.
Che, H., Zhang, J., Liu, Q., and Zhao, M.: A driving factor for harmful algal
blooms in the East China Sea coastal marine ecosystems – Implications of
Kuroshio subsurface water invasion, Mar. Pollut. Bull., 181, 113871,
https://doi.org/10.1016/j.marpolbul.2022.113871, 2022.
Chen, L., Liu, J., Xu, G., and Li, F.: Phytoplankton productivity and
community structure variations over the last 160 years in the East China Sea
coast in response to natural and human-induced environmental changes, The
Holocene, 29, 1145–1154, https://doi.org/10.1177/0959683619838040, 2019a.
Chen, X., Strokal, M., Kroeze, C., Ma, L., Shen, Z., Wu, J., Chen, X., and
Shi, X.: Seasonality in river export of nitrogen: A modelling approach for
the Yangtze River, Sci. Total Environ., 671, 1282–1292,
https://doi.org/10.1016/j.scitotenv.2019.03.323, 2019b.
Chen, X., Strokal, M., Kroeze, C., Supit, I., Wang, M., Ma, L., Chen, X., and
Shi, X.: Modeling the Contribution of Crops to Nitrogen Pollution in the
Yangtze River, Environ. Sci. Technol., 54, 11929–11939,
https://doi.org/10.1021/acs.est.0c01333, 2020.
Chi, L., Song, X., Yuan, Y., Wang, W., Zhou, P., Fan, X., Cao, X., and Yu,
Z.: Distribution and key influential factors of dissolved oxygen off the
Changjiang River Estuary (CRE) and its adjacent waters in China, Mar.
Pollut. Bull., 125, 440–450, https://doi.org/10.1016/j.marpolbul.2017.09.063,
2017.
Cloern, J. E.: Turbidity as a control on phytoplankton biomass and
productivity in estuaries, Cont. Shelf Res., 7, 1367–1381,
https://doi.org/10.1016/0278-4343(87)90042-2, 1987.
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,
https://doi.org/10.1016/j.csr.2004.02.003, 2004.
Dai, Z., Du, J., Zhang, X., Su, N., and Li, J.: Variation of Riverine
Material Loads and Environmental Consequences on the Changjiang (Yangtze)
Estuary in Recent Decades (1955–2008)†, Environ. Sci. Technol.,
45, 223–227, https://doi.org/10.1021/es103026a, 2011.
Dee, D. P., Uppala, S. M., Simmons, A. J., Berrisford, P., Poli, P.,
Kobayashi, S., Andrae, U., Balmaseda, M. A., Balsamo, G., Bauer, P.,
Bechtold, P., Beljaars, A. C. M., van de Berg, L., Bidlot, J., Bormann, N.,
Delsol, C., Dragani, R., Fuentes, M., Geer, A. J., Haimberger, L., Healy, S.
B., Hersbach, H., Hólm, E. V., Isaksen, L., Kållberg, P.,
Köhler, M., Matricardi, M., McNally, A. P., Monge-Sanz, B. M.,
Morcrette, J.-J., Park, B.-K., Peubey, C., de Rosnay, P., Tavolato, C.,
Thépaut, J.-N., and Vitart, F.: The ERA-Interim reanalysis: configuration
and performance of the data assimilation system, Q. J. R. Meteorol. Soc.,
137, 553–597, https://doi.org/10.1002/qj.828, 2011.
Diaz, R. J. and Rosenberg, R.: Spreading Dead Zones and Consequences for
Marine Ecosystems, Science, 321, 926–929,
https://doi.org/10.1126/science.1156401, 2008.
Fennel, K. and Laurent, A.: N and P as ultimate and proximate limiting
nutrients in the northern Gulf of Mexico: implications for hypoxia reduction
strategies, Biogeosciences, 15, 3121–3131, https://doi.org/10.5194/bg-15-3121-2018,
2018.
Fennel, K. and Testa, J. M.: Biogeochemical Controls on Coastal Hypoxia,
Ann. Rev. Mar. Sci., 11, 105–130,
https://doi.org/10.1146/annurev-marine-010318-095138, 2019.
Fennel, K., Wilkin, J., Levin, J., Moisan, J., O'Reilly, J., and Haidvogel,
D.: Nitrogen cycling in the Middle Atlantic Bight: Results from a
three-dimensional model and implications for the North Atlantic nitrogen
budget, Global Biogeochem. Cy., 20, GB3007, https://doi.org/10.1029/2005GB002456,
2006.
Fennel, K., Brady, D., DiToro, D., Fulweiler, R. W., Gardner, W. S., Giblin,
A., McCarthy, M. J., Rao, A., Seitzinger, S., Thouvenot-Korppoo, M., and
Tobias, C.: Modeling denitrification in aquatic sediments, Biogeochemistry,
93, 159–178, https://doi.org/10.1007/s10533-008-9270-z, 2009.
Fennel, K., Hetland, R., Feng, Y., and DiMarco, S.: A coupled
physical-biological model of the Northern Gulf of Mexico shelf: model
description, validation and analysis of phytoplankton variability,
Biogeosciences, 8, 1881–1899, https://doi.org/10.5194/bg-8-1881-2011, 2011.
Fennel, K., Hu, J., Laurent, A., Marta-Almeida, M., and Hetland, R.:
Sensitivity of hypoxia predictions for the northern Gulf of Mexico to
sediment oxygen consumption and model nesting, J. Geophys. Res.-Ocean.,
118, 990–1002, https://doi.org/10.1002/jgrc.20077, 2013.
Gao, L., Li, D., Ishizaka, J., Zhang, Y., Zong, H., and Guo, L.: Nutrient
dynamics across the river-sea interface in the Changjiang (Yangtze River)
estuary-East China Sea region, Limnol. Oceanogr., 60, 2207–2221,
https://doi.org/10.1002/lno.10196, 2015.
Garcia, H. E., Boyer, T. P., Locarnini, R. A., Antonov, J. I., Mishonov, A.
V., Baranova, O. K., Zweng, M. M., Reagan, J. R., Johnson, D. R., and
Levitus, S.: World Ocean Atlas 2013, Volume 3: Dissolved oxygen, apparent
oxygen utilization, and oxygen saturation, National Oceanic and Atmospheric
Administration (NOAA), Silver Spring, MD, Silver Spring, MD, NOAA, https://doi.org/10.7289/V5XG9P2W, 2013a.
Garcia, H. E., Locarnini, R., Boyer, T. P., Antonov, J. I., Baranova, O. K.,
Zweng, M. M., Reagan, J. R., and Johnson, D. R.: World Ocean Atlas 2013,
Volume 4: Dissolved Inorganic Nutrients (phosphate, nitrate, silicate),
National Oceanic and Atmospheric Administration (NOAA), Silver Spring, MD, NOAA, https://doi.org/10.7289/V5J67DWD,
2013b.
Ge, J., Shi, S., Liu, J., Xu, Y., Chen, C., Bellerby, R., and Ding, P.:
Interannual Variabilities of Nutrients and Phytoplankton off the Changjiang
Estuary in Response to Changing River Inputs, J. Geophys. Res.-Ocean.,
125, e2019JC015595, https://doi.org/10.1029/2019JC015595, 2020.
Glibert, P. M., Maranger, R., Sobota, D. J., and Bouwman, L.: The Haber
Bosch–harmful algal bloom (HB–HAB) link, Environ. Res. Lett., 9,
105001, https://doi.org/10.1088/1748-9326/9/10/105001, 2014.
Große, F., Fennel, K., Zhang, H., and Laurent, A.: Quantifying the
contributions of riverine vs. oceanic nitrogen to hypoxia in the East China
Sea, Biogeosciences, 17, 2701–2714, https://doi.org/10.5194/bg-17-2701-2020, 2020.
Guo, C., Bai, Z., Shi, X., Chen, X., Chadwick, D., Strokal, M., Zhang, F.,
Ma, L., and Chen, X.: Challenges and strategies for agricultural green
development in the Yangtze River Basin, J. Integr. Environ. Sci., 18,
37–54, https://doi.org/10.1080/1943815X.2021.1883674, 2021.
Haidvogel, D. B., Arango, H., Budgell, W. P., Cornuelle, B. D., Curchitser,
E., Lorenzo, E. Di, Fennel, K., Geyer, W. R., Hermann, A. J., Lanerolle, L.,
Levin, J., McWilliams, J. C., Miller, A. J., Moore, A. M., Powell, T. M.,
Shchepetkin, A. F., Sherwood, C. R., Signell, R. P., Warner, J. C., and
Wilkin, J.: Ocean forecasting in terrain-following coordinates: Formulation
and skill assessment of the Regional Ocean Modeling System, J. Comput. Phys.,
227, 3595–3624, https://doi.org/10.1016/j.jcp.2007.06.016, 2008 (code available at http://myroms.org, last access: 10 August 2019).
Harrison, J. A., Bouwman, A. F., Mayorga, E., and Seitzinger, S.: Magnitudes
and sources of dissolved inorganic phosphorus inputs to surface fresh waters
and the coastal zone: A new global model, Global Biogeochem. Cy., 24,
GB1003, https://doi.org/10.1029/2009GB003590, 2010.
Harrison, P. J., Hu, M. H., Yang, Y. P., and Lu, X.: Phosphate limitation in
estuarine and coastal waters of China, J. Exp. Mar. Bio. Ecol., 140,
79–87, https://doi.org/10.1016/0022-0981(90)90083-O, 1990.
Heisler, J., Glibert, P. M., Burkholder, J. M., Anderson, D. M., Cochlan,
W., Dennison, W. C., Dortch, Q., Gobler, C. J., Heil, C. A., Humphries, E.,
Lewitus, A., Magnien, R., Marshall, H. G., Sellner, K., Stockwell, D. A.,
Stoecker, D. K., and Suddleson, M.: Eutrophication and harmful algal blooms:
A scientific consensus, Harmful Algae, 8, 3–13,
https://doi.org/10.1016/j.hal.2008.08.006, 2008.
Hu, M., Liu, Y., Zhang, Y., Shen, H., Yao, M., Dahlgren, R. A., and Chen, D.:
Long-term (1980–2015) changes in net anthropogenic phosphorus inputs and
riverine phosphorus export in the Yangtze River basin, Water Res., 177,
115779, https://doi.org/10.1016/j.watres.2020.115779, 2020.
Huang, T.-H., Chen, C.-T. A., Lee, J., Wu, C.-R., Wang, Y.-L., Bai, Y., He,
X., Wang, S.-L., Kandasamy, S., Lou, J.-Y., Tsuang, B.-J., Chen, H.-W.,
Tseng, R.-S., and Yang, Y. J.: East China Sea increasingly gains limiting
nutrient P from South China Sea, Sci. Rep., 9, 5648,
https://doi.org/10.1038/s41598-019-42020-4, 2019.
Jiang, Z., Liu, J., Chen, J., Chen, Q., Yan, X., Xuan, J., and Zeng, J.:
Responses of summer phytoplankton community to drastic environmental changes
in the Changjiang (Yangtze River) estuary during the past 50 years, Water
Res., 54, 1–11, https://doi.org/10.1016/j.watres.2014.01.032, 2014.
Kemp, W. M., Boynton, W. R., Adolf, J. E., Boesch, D. F., Boicourt, W. C.,
Brush, G., Cornwell, J. C., Fisher, T. R., Glibert, P. M., Hagy, J.,
Harding, L. W., Houde, E. D., Kimmel, D. G., Miller, W. D., Newell, R. I.
E., Roman, M. R., Smith, E. M., and Stevenson, J. C.: Eutrophication of
Chesapeake Bay: historical trends and ecological interactions, Mar. Ecol.
Prog. Ser., 303, 1–29, https://doi.org/10.3354/meps303001, 2005.
Kidwell, D. M., Lewitus, A. J., Brandt, S., Jewett, E. B., and Mason, D. M.:
Ecological impacts of hypoxia on living resources, J. Exp. Mar. Bio. Ecol.,
381, S1–S3, https://doi.org/10.1016/j.jembe.2009.07.009, 2009.
Kodama, T., Morimoto, A., Takikawa, T., Ito, M., Igeta, Y., Abe, S.,
Fukudome, K.-I., Honda, N., and Katoh, O.: Presence of high nitrate to
phosphate ratio subsurface water in the Tsushima Strait during summer, J.
Oceanogr., 73, 759–769, https://doi.org/10.1007/s10872-017-0430-4, 2017.
Laurent, A. and Fennel, K.: Simulated reduction of hypoxia in the northern
Gulf of Mexico due to phosphorus limitation, Elem. Sci. Anthr., 2,
000022, https://doi.org/10.12952/journal.elementa.000022, 2014.
Laurent, A. and Fennel, K.: Modeling River-Induced Phosphorus Limitation in
the Context of Coastal Hypoxia, in: Modeling Coastal Hypoxia, edited by:
Justic, D., Rose, K. A., Hetland, R. D., and Fennel, K., 149–171, Springer
International Publishing, Cham, Springer, ISBN: 978-3-319-54569-1, 2017.
Laurent, A., Fennel, K., Hu, J., and Hetland, R.: Simulating the effects of
phosphorus limitation in the Mississippi and Atchafalaya River plumes,
Biogeosciences, 9, 4707–4723, https://doi.org/10.5194/bg-9-4707-2012, 2012.
Laurent, A., Fennel, K., Cai, W.-J., Huang, W.-J., Barbero, L., and
Wanninkhof, R.: Eutrophication-induced acidification of coastal waters in
the northern Gulf of Mexico: insights into origin and processes from a
coupled physical-biogeochemical model, Geophys. Res. Lett., 44, 946–956,
https://doi.org/10.1002/2016GL071881, 2017.
Levin, L. A., Ekau, W., Gooday, A. J., Jorissen, F., Middelburg, J. J.,
Naqvi, S. W. A., Neira, C., Rabalais, N. N., and Zhang, J.: Effects of
natural and human-induced hypoxia on coastal benthos, Biogeosciences, 6,
2063–2098, https://doi.org/10.5194/bg-6-2063-2009, 2009.
Li, H.-M., Tang, H.-J., Shi, X.-Y., Zhang, C.-S., and Wang, X.-L.: Increased
nutrient loads from the Changjiang (Yangtze) River have led to increased
Harmful Algal Blooms, Harmful Algae, 39, 92–101,
https://doi.org/10.1016/j.hal.2014.07.002, 2014.
Li, J., Glibert, P., Zhou, M., Lu, S., and Lu, D.: Relationships between
nitrogen and phosphorus forms and ratios and the development of
dinoflagellate blooms in the East China Sea, Mar. Ecol. Prog. Ser., 383,
11–26, https://doi.org/10.3354/meps07975, 2009.
Li, W., Ge, J., Ding, P., Ma, J., Glibert, P. M., and Liu, D.: Effects of
Dual Fronts on the Spatial Pattern of Chlorophyll-a Concentrations in and
off the Changjiang River Estuary, Estuar. Coast., 44, 1408–1418,
https://doi.org/10.1007/s12237-020-00893-z, 2021.
Li, X., Bianchi, T. S., Yang, Z., Osterman, L. E., Allison, M. A., DiMarco,
S. F., and Yang, G.: Historical trends of hypoxia in Changjiang River
estuary: Applications of chemical biomarkers and microfossils, J. Mar.
Syst., 86, 57–68, https://doi.org/10.1016/j.jmarsys.2011.02.003, 2011.
Lin, X., Liu, M., Hou, L., Gao, D., Li, X., Lu, K., and Gao, J.: Nitrogen
Losses in Sediments of the East China Sea: Spatiotemporal Variations,
Controlling Factors, and Environmental Implications, J. Geophys. Res.-Biogeo., 122, 2699–2715, https://doi.org/10.1002/2017JG004036, 2017.
Liu, S. M., Zhang, J., and Chen, H.: Nutrients in the Changjiang and its
tributaries, Biogeochemistry, 62, 1–18, https://doi.org/10.1023/A:1021162214304, 2003.
Liu, S. M., Hong, G.-H., Zhang, J., Ye, X. W., and Jiang, X. L.: Nutrient
budgets for large Chinese estuaries, Biogeosciences, 6, 2245–2263,
https://doi.org/10.5194/bg-6-2245-2009, 2009.
Liu, X., Beusen, A. H. W., Van Beek, L. P. H., Mogollón, J. M., Ran, X.,
and Bouwman, A. F.: Exploring spatiotemporal changes of the Yangtze River
(Changjiang) nitrogen and phosphorus sources, retention and export to the
East China Sea and Yellow Sea, Water Res., 142, 246–255,
https://doi.org/10.1016/j.watres.2018.06.006, 2018.
Liu, Z., Gan, J., Wu, H., Hu, J., Cai, Z., and Deng, Y.: Advances on Coastal
and Estuarine Circulations Around the Changjiang Estuary in the Recent
Decades (2000–2020), Front. Mar. Sci., 8, 615929, https://doi.org/10.3389/fmars.2021.615929,
2021.
Locarnini, R. A., Mishonov, A. V., Antonov, J. I., Boyer, T. P., Garcia, H.
E., Baranova, O. K., Zweng, M. M., Paver, C. R., Reagan, J. R., Johnson, D.
R., Hamilton, M., and Seidov, D.: World Ocean Atlas 2013, Vol. 1,
Temperature, edited by: Levitus, S., A. Mishonov Technical Ed., NOAA, NOAA Atlas NESDIS
73, https://doi.org/10.7289/V55X26VD, 2013.
Lohrenz, S. E., Gary, L., Lang, G. A., Chen, X., and Michael, J.: Variations
in primary production of northern Gulf of Mexico continental shelf waters
linked to nutrient inputs from the Mississippi River, Cont. Shelf Res., 155, 45–54, 1997.
Lohrenz, S. E., Fahnenstiel, G. L., Redalje, D. G., Lang, G. a., Dagg, M.
J., Whitledge, T. E., and Dortch, Q.: Nutrients, irradiance, and mixing as
factors regulating primary production in coastal waters impacted by the
Mississippi River plume, Cont. Shelf Res., 19, 1113–1141,
https://doi.org/10.1016/S0278-4343(99)00012-6, 1999.
Malone, T. C., Conley, D. J., Fisher, T. R., Glibert, P. M., Harding, L. W.,
and Sellner, K. G.: Scales of Nutrient-Limited Phytoplankton in Chesapeake
Bay Productivity, Estuaries, 19, 371–385, 1996.
Moon, J., Lee, K., Lim, W., Lee, E., Dai, M., Choi, Y., Han, I., Shin, K.,
Kim, J., and Chae, J.: Anthropogenic nitrogen is changing the East China and
Yellow seas from being N deficient to being P deficient, Limnol. Oceanogr.,
66, 914–924, https://doi.org/10.1002/lno.11651, 2021.
Ning, X., Lin, C., Su, J., Liu, C., Hao, Q., and Le, F.: Long-term changes of
dissolved oxygen, hypoxia, and the responses of the ecosystems in the East
China Sea from 1975 to 1995, J. Oceanogr., 67, 59–75,
https://doi.org/10.1007/s10872-011-0006-7, 2011.
O'Boyle, S., Wilkes, R., McDermott, G., Ní Longphuirt, S., and Murray,
C.: Factors affecting the accumulation of phytoplankton biomass in Irish
estuaries and nearshore coastal waters: A conceptual model, Estuar. Coast.
Shelf Sci., 155, 75–88, https://doi.org/10.1016/j.ecss.2015.01.007, 2015.
Ou, L., Qin, X., Shi, X., Feng, Q., Zhang, S., Lu, S., and Qi, Y.: Alkaline
phosphatase activities and regulation in three harmful Prorocentrum species
from the coastal waters of the East China Sea, Microb. Ecol., 79,
459–471, https://doi.org/10.1007/s00248-019-01399-3, 2020.
Paerl, H. W.: Controlling Eutrophication along the Freshwater–Marine
Continuum: Dual Nutrient (N and P) Reductions are Essential, Estuar.
Coast., 32, 593–601, https://doi.org/10.1007/s12237-009-9158-8, 2009.
Paerl, H. W., Valdes, L. M., Joyner, A. R., Piehler, M. F., and Lebo, M. E.:
Solving problems resulting from solutions: evolution of a dual nutrient
management strategy for the eutrophying Neuse River Estuary, North
Carolina., Environ. Sci. Technol., 38, 3068–3073, 2004.
Paerl, H. W., Gardner, W. S., Havens, K. E., Joyner, A. R., McCarthy, M. J.,
Newell, S. E., Qin, B., and Scott, J. T.: Mitigating cyanobacterial harmful
algal blooms in aquatic ecosystems impacted by climate change and
anthropogenic nutrients, Harmful Algae, 54, 213–222,
https://doi.org/10.1016/J.HAL.2015.09.009, 2016.
Rabalais, N. N. and Turner, R. E. (Eds.): Coastal Hypoxia: Consequences for
Living Resources and Ecosystems, American Geophysical Union, Washington, DC, American Geophysical Union, https://doi.org/10.1029/CE058, 2001.
Scavia, D. and Donnelly, K. A.: Reassessing Hypoxia Forecasts for the Gulf of
Mexico, Environ. Sci. Technol., 41, 8111–8117, https://doi.org/10.1021/es0714235,
2007.
Seitzinger, S. P. and Giblin, A. E.: Estimating denitrification in North
Atlantic continental shelf sediments, Biogeochemistry, 35, 235–260,
https://doi.org/10.1007/BF02179829, 1996.
Seitzinger, S. P. and Harrison, J. A.: Land-Based Nitrogen Sources and Their
Delivery to Coastal Systems, in Nitrogen in the Marine Environment,
469–510, Elsevier, Academic Press, https://doi.org/10.1016/B978-0-12-372522-6.00009-8, 2008.
Shi, S., Xu, Y., Li, W., and Ge, J.: Long-term response of an estuarine
ecosystem to drastic nutrients changes in the Changjiang River during the
last 59 years: A modeling perspective, Front. Mar. Sci., 9,
https://doi.org/10.3389/fmars.2022.1012127, 2022.
Smith, M. D., Oglend, A., Kirkpatrick, A. J., Asche, F., Bennear, L. S.,
Craig, J. K., and Nance, J. M.: Seafood prices reveal impacts of a major
ecological disturbance, P. Natl. Acad. Sci. USA, 114, 1512–1517,
https://doi.org/10.1073/pnas.1617948114, 2017.
Strokal, M., Yang, H., Zhang, Y., Kroeze, C., Li, L., Luan, S., Wang, H.,
Yang, S., and Zhang, Y.: Increasing eutrophication in the coastal seas of
China from 1970 to 2050, Mar. Pollut. Bull., 85, 123–140,
https://doi.org/10.1016/j.marpolbul.2014.06.011, 2014.
Strokal, M., Ma, L., Bai, Z., Luan, S., Kroeze, C., Oenema, O., Velthof, G.,
and Zhang, F.: Alarming nutrient pollution of Chinese rivers as a result of
agricultural transitions, Environ. Res. Lett., 11, 024014,
https://doi.org/10.1088/1748-9326/11/2/024014, 2016.
Strokal, M., Kahil, T., Wada, Y., Albiac, J., Bai, Z., Ermolieva, T.,
Langan, S., Ma, L., Oenema, O., Wagner, F., Zhu, X., and Kroeze, C.:
Cost-effective management of coastal eutrophication: A case study for the
Yangtze river basin, Resour. Conserv. Recycl., 154, 104635,
https://doi.org/10.1016/j.resconrec.2019.104635, 2020.
Sylvan, J. B., Dortch, Q., Nelson, D. M., Brown, A. F. M., Morrison, W., and
Ammerman, J. W.: Phosphorus limits phytoplankton growth on the Louisiana
shelf during the period of hypoxia formation., Environ. Sci. Technol.,
40, 7548–7553, 2006.
Tong, Y., Zhao, Y., Zhen, G., Chi, J., Liu, X., Lu, Y., Wang, X., Yao, R.,
Chen, J., and Zhang, W.: Nutrient Loads Flowing into Coastal Waters from the
Main Rivers of China (2006–2012), Sci. Rep., 5, 16678,
https://doi.org/10.1038/srep16678, 2015.
Tseng, Y.-F., Lin, J., Dai, M., and Kao, S.-J.: Joint effect of freshwater
plume and coastal upwelling on phytoplankton growth off the Changjiang
River, Biogeosciences, 11, 409–423, https://doi.org/10.5194/bg-11-409-2014, 2014.
Turner, R. E., Rabalais, N. N., and Justic, D.: Gulf of Mexico Hypoxia:
Alternate States and a Legacy, Environ. Sci. Technol., 42, 2323–2327,
https://doi.org/10.1021/es071617k, 2008.
Umlauf, L. and Burchard, H.: A generic length-scale equation for geophysical
turbulence models, J. Mar. Res., 61, 235–265,
https://doi.org/10.1357/002224003322005087, 2003.
Van Meter, K. J., Van Cappellen, P., and Basu, N. B.: Legacy nitrogen may
prevent achievement of water quality goals in the Gulf of Mexico, Science, 360, 427–430, https://doi.org/10.1126/science.aar4462, 2018.
Wang, H., Dai, M., Liu, J., Kao, S.-J., Zhang, C., Cai, W.-J., Wang, G.,
Qian, W., Zhao, M., and Sun, Z.: Eutrophication-Driven Hypoxia in the East
China Sea off the Changjiang Estuary, Environ. Sci. Technol., 50,
2255–2263, https://doi.org/10.1021/acs.est.5b06211, 2016.
Wang, J. and Wu, J.: Occurrence and potential risks of harmful algal blooms
in the East China Sea, Sci. Total Environ., 407, 4012–4021,
https://doi.org/10.1016/j.scitotenv.2009.02.040, 2009.
Wang, J., Yan, W., Chen, N., Li, X., and Liu, L.: Modeled long-term changes
of DIN : DIP ratio in the Changjiang River in relation to Chl-a and DO
concentrations in adjacent estuary, Estuar. Coast. Shelf Sci., 166,
153–160, https://doi.org/10.1016/j.ecss.2014.11.028, 2015.
Wang, K., Chen, J., Jin, H., Li, H., Gao, S., Xu, J., Lu, Y., Huang, D.,
Hao, Q., and Weng, H.: Summer nutrient dynamics and biological carbon uptake
rate in the Changjiang River plume inferred using a three end-member mixing
model, Cont. Shelf Res., 91, 192–200, https://doi.org/10.1016/j.csr.2014.09.013, 2014.
Wang, M., Kroeze, C., Strokal, M., Vliet, M. T. H., and Ma, L.: Global Change
Can Make Coastal Eutrophication Control in China More Difficult, Earth's
Futur., 8, e2019EF001280, https://doi.org/10.1029/2019EF001280, 2020.
Westphal, K., Musolff, A., Graeber, D., and Borchardt, D.: Controls of point
and diffuse sources lowered riverine nutrient concentrations asynchronously,
thereby warping molar N:P ratios, Environ. Res. Lett., 15, 104009,
https://doi.org/10.1088/1748-9326/ab98b6, 2020.
Wong, G. T. F., Gong, G.-C., Liu, K.-K., and Pai, S.-C.: `Excess Nitrate' in
the East China Sea, Estuar. Coast. Shelf Sci., 46, 411–418,
https://doi.org/10.1006/ecss.1997.0287, 1998.
Wu, Y., Xi, X., Tang, X., Luo, D., Gu, B., Lam, S. K., Vitousek, P. M., and
Chen, D.: Policy distortions, farm size, and the overuse of agricultural
chemicals in China, P. Natl. Acad. Sci. USA, 115, 7010–7015,
https://doi.org/10.1073/pnas.1806645115, 2018.
Wurtsbaugh, W. A., Paerl, H. W., and Dodds, W. K.: Nutrients, eutrophication
and harmful algal blooms along the freshwater to marine continuum, Wiley
Interdiscip. Rev. Water, 6, e1373, https://doi.org/10.1002/wat2.1373, 2019.
Xing, L., Zhao, M., Zhang, T., Yu, M., Duan, S., Zhang, R., Huh, C.-A.,
Liao, W.-H., and Feng, X.: Ecosystem responses to anthropogenic and natural
forcing over the last 100 years in the coastal areas of the East China Sea,
The Holocene, 26, 669–677, https://doi.org/10.1177/0959683615618248, 2016.
Yan, W., Zhang, S., Sun, P., and Seitzinger, S. P.: How do nitrogen inputs to
the Changjiang basin impact the Changjiang River nitrate: A temporal
analysis for 1968–1997, Global Biogeochem. Cy., 17, 1091,
https://doi.org/10.1029/2002GB002029, 2003.
Yan, W., Mayorga, E., Li, X., Seitzinger, S. P., and Bouwman, A. F.:
Increasing anthropogenic nitrogen inputs and riverine DIN exports from the
Changjiang River basin under changing human pressures, Global Biogeochem.
Cy., 24, GB0A06, https://doi.org/10.1029/2009GB003575, 2010.
Yang, D., Yin, B., Liu, Z., Bai, T., Qi, J., and Chen, H.: Numerical study on
the pattern and origins of Kuroshio branches in the bottom water of southern
East China Sea in summer, J. Geophys. Res.-Ocean., 117, C02014,
https://doi.org/10.1029/2011JC007528, 2012.
Yu, C., Huang, X., Chen, H., Godfray, H. C. J., Wright, J. S., Hall, J. W.,
Gong, P., Ni, S., Qiao, S., Huang, G., Xiao, Y., Zhang, J., Feng, Z., Ju,
X., Ciais, P., Stenseth, N. C., Hessen, D. O., Sun, Z., Yu, L., Cai, W., Fu,
H., Huang, X., Zhang, C., Liu, H., and Taylor, J.: Managing nitrogen to
restore water quality in China, Nature, 567, 516–520,
https://doi.org/10.1038/s41586-019-1001-1, 2019.
Yu, L. and Gan, J.: Reversing impact of phytoplankton phosphorus limitation
on coastal hypoxia due to interacting changes in surface production and
shoreward bottom oxygen influx, Water Res., 212, 118094,
https://doi.org/10.1016/j.watres.2022.118094, 2022.
Yu, L., Fennel, K., Laurent, A., Murrell, M. C., and Lehrter, J. C.:
Numerical analysis of the primary processes controlling oxygen dynamics on
the Louisiana shelf, Biogeosciences, 12, 2063–2076,
https://doi.org/10.5194/bg-12-2063-2015, 2015.
Zhang, H., Fennel, K., Laurent, A., and Bian, C.: A numerical model study of
the main factors contributing to hypoxia and its interannual and short-term
variability in the East China Sea, Biogeosciences, 17, 5745–5761,
https://doi.org/10.5194/bg-17-5745-2020, 2020.
Zhou, F., Chai, F., Huang, D., Xue, H., Chen, J., Xiu, P., Xuan, J., Li, J.,
Zeng, D., Ni, X., and Wang, K.: Investigation of hypoxia off the Changjiang
Estuary using a coupled model of ROMS-CoSiNE, Prog. Oceanogr., 159,
237–254, https://doi.org/10.1016/j.pocean.2017.10.008, 2017.
Zhou, M., Shen, Z., and Yu, R.: Responses of a coastal phytoplankton
community to increased nutrient input from the Changjiang (Yangtze) River,
Cont. Shelf Res., 28, 1483–1489, https://doi.org/10.1016/j.csr.2007.02.009, 2008.
Zhu, Z.-Y., Ng, W.-M., Liu, S.-M., Zhang, J., Chen, J.-C., and Wu, Y.:
Estuarine phytoplankton dynamics and shift of limiting factors: A study in
the Changjiang (Yangtze River) Estuary and adjacent area, Estuar. Coast.
Shelf Sci., 84, 393–401, https://doi.org/10.1016/j.ecss.2009.07.005, 2009.
Zweng, M. M., Reagan, J. R., Antonov, J. I., Locarnini, R. A., Mishonov, A.
V., Boyer, T. P., Garcia, H. E., Baranova, O. K., Johnson, D. R., Seidov, D.,
and Biddle, M. M.: World Ocean Atlas 2013, Volume 2, Salinity, edited by: Levitus, S.,
A. Mishonov Technical Ed., NOAA, NOAA Atlas NESDIS 74, https://doi.org/10.7289/V5251G4D, 2013.
Short summary
The Changjiang is the main terrestrial source of nutrients to the East China Sea (ECS). Nutrient delivery to the ECS has been increasing since the 1960s, resulting in low oxygen (hypoxia) during phytoplankton decomposition in summer. River phosphorus (P) has increased less than nitrogen, and therefore, despite the large nutrient delivery, phytoplankton growth can be limited by the lack of P. Here, we investigate this link between P limitation, phytoplankton production/decomposition, and hypoxia.
The Changjiang is the main terrestrial source of nutrients to the East China Sea (ECS). Nutrient...
Altmetrics
Final-revised paper
Preprint