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
Geosci. Model Dev., 17, 8697–8733, https://doi.org/10.5194/gmd-17-8697-2024, https://doi.org/10.5194/gmd-17-8697-2024, 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 ocean 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, Andrew Moore, Stefano Ciavatta, and Katja Fennel
State Planet, 5-opsr, 12, https://doi.org/10.5194/sp-5-opsr-12-2025, https://doi.org/10.5194/sp-5-opsr-12-2025, 2025
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 a single nutrient to fully explicit representations of multiple nutrients, trophic levels, and functional groups. Uncertainty sources are the lack of knowledge about the parameterizations, the initial and boundary conditions, and the lack of observations.
Kyoko Ohashi, Arnaud Laurent, Christoph Renkl, Jinyu Sheng, Katja Fennel, and Eric Oliver
Geosci. Model Dev., 17, 8697–8733, https://doi.org/10.5194/gmd-17-8697-2024, https://doi.org/10.5194/gmd-17-8697-2024, 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 ocean 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
Effects of submarine groundwater on nutrient concentration and primary production in a deep bay of the Japan Sea
The bacteria–protist link as a main route of dissolved organic matter across contrasting productivity areas on the Patagonian Shelf
Ocean alkalinity enhancement (OAE) does not cause cellular stress in a phytoplankton community of the subtropical Atlantic Ocean
Reviews and syntheses: On increasing hypoxia in eastern boundary upwelling systems – zooplankton under metabolic stress
Technical note: Testing a new approach for the determination of N2 fixation rates by coupling a membrane equilibrator to a mass spectrometer for long-term observations
Long-term variations in pH in coastal waters along the Korean Peninsula
The effect of carbonate mineral additions on biogeochemical conditions in surface sediments and benthic–pelagic exchange fluxes
Evaluating ocean alkalinity enhancement as a carbon dioxide removal strategy in the North Sea
Assessing the impacts of simulated ocean alkalinity enhancement on viability and growth of nearshore species of phytoplankton
Responses of microbial metabolic rates to non-equilibrated silicate- versus calcium-based ocean alkalinity enhancement
High metabolic zinc demand within native Amundsen and Ross sea phytoplankton communities determined by stable isotope uptake rate measurements
The influence of zooplankton and oxygen on the particulate organic carbon flux in the Benguela Upwelling System
Reviews and syntheses: Biological indicators of low-oxygen stress in marine water-breathing animals
Temperature-enhanced effects of iron on Southern Ocean phytoplankton
Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth system model
The Northeast Greenland Shelf as a potential late-summer CO2 source to the atmosphere
Spring-neap tidal cycles modulate the strength of the carbon source at the estuary-coast interface
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
Depositional controls and budget of organic carbon burial in fine-grained sediments of the North Sea – the Helgoland Mud Area as a test field
Improved understanding of eutrophication trends, indicators and problem areas using machine learning
Distribution of nutrients and dissolved organic matter in a eutrophic equatorial estuary: the Johor River and the East Johor Strait
Amplified bottom water acidification rates on the Bering Sea shelf from 1970–2022
Investigating the effect of silicate- and calcium-based ocean alkalinity enhancement on diatom silicification
Ocean alkalinity enhancement using sodium carbonate salts does not lead to measurable changes in Fe dynamics in a mesocosm experiment
Quantification and mitigation of bottom-trawling impacts on sedimentary organic carbon stocks in the North Sea
Influence of ocean alkalinity enhancement with olivine or steel slag on a coastal plankton community in Tasmania
Multi-model comparison of trends and controls of near-bed oxygen concentration on the northwest European continental shelf under climate change
Picoplanktonic methane production in eutrophic surface waters
Vertical mixing alleviates autumnal oxygen deficiency in the central North Sea
Hypoxia also occurs in small highly turbid estuaries: the example of the Charente (Bay of Biscay)
Seasonality and response of ocean acidification and hypoxia to major environmental anomalies in the southern Salish Sea, North America (2014–2018)
Oceanographic processes driving low-oxygen conditions inside Patagonian fjords
Above- and belowground plant mercury dynamics in a salt marsh estuary in Massachusetts, USA
Variability and drivers of carbonate chemistry at shellfish aquaculture sites in the Salish Sea, British Columbia
Unusual Hemiaulus bloom influences ocean productivity in Northeastern US Shelf waters
Insights into carbonate environmental conditions in the Chukchi Sea
UAV approaches for improved mapping of vegetation cover and estimation of carbon storage of small saltmarshes: examples from Loch Fleet, northeast Scotland
Iron “ore” nothing: benthic iron fluxes from the oxygen-deficient Santa Barbara Basin enhance phytoplankton productivity in surface waters
Marine anoxia initiates giant sulfur-oxidizing bacterial mat proliferation and associated changes in benthic nitrogen, sulfur, and iron cycling in the Santa Barbara Basin, California Borderland
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
Menghong Dong, Xinyu Guo, Takuya Matsuura, Taichi Tebakari, and Jing Zhang
Biogeosciences, 22, 2383–2402, https://doi.org/10.5194/bg-22-2383-2025, https://doi.org/10.5194/bg-22-2383-2025, 2025
Short summary
Short summary
Submarine groundwater discharge (SGD), a common coastal hydrological process that involves submarine inflow of groundwater into the sea, is associated with a large nutrient load. To clarify the distribution of SGD-derived nutrients after release at the bottom of the sea and their contribution to phytoplankton growth in the marine ecosystem, we modeled the SGD process in Toyama Bay using a specialized computer code that can distinguish SGD-derived nutrients from nutrients from other sources.
M. Celeste López-Abbate, John E. Garzón-Cardona, Ricardo Silva, Juan-Carlos Molinero, Laura A. Ruiz-Etcheverry, Ana M. Martínez, Azul S. Gilabert, and Rubén J. Lara
Biogeosciences, 22, 2309–2325, https://doi.org/10.5194/bg-22-2309-2025, https://doi.org/10.5194/bg-22-2309-2025, 2025
Short summary
Short summary
This study explores how microbial dynamics influence the dissolved organic matter (DOM) pool in the Patagonian Shelf. Despite high phytoplankton biomass, selective grazing on fast-growing bacteria led to DOM accumulation, likely due to reduced DOM-consuming bacteria and added egestion compounds. Experiments showed that bacteria not only acted as a carbon sink through mineralization but also transferred assimilated carbon dioxide (CO2) to higher trophic levels.
Librada Ramírez, Leonardo J. Pozzo-Pirotta, Aja Trebec, Víctor Manzanares-Vázquez, José L. Díez, Javier Arístegui, Ulf Riebesell, Stephen D. Archer, and María Segovia
Biogeosciences, 22, 1865–1886, https://doi.org/10.5194/bg-22-1865-2025, https://doi.org/10.5194/bg-22-1865-2025, 2025
Short summary
Short summary
We studied the potential effects of increasing ocean alkalinity on a natural plankton community in subtropical waters of the Atlantic near Gran Canaria, Spain. Alkalinity is the capacity of water to resist acidification, and plankton are usually microscopic plants (phytoplankton) and animals (zooplankton), often less than 2.5 cm in length. This study suggests that increasing ocean alkalinity did not have a significant negative impact on the plankton community studied.
Leissing Frederick, Mauricio A. Urbina, and Ruben Escribano
Biogeosciences, 22, 1839–1852, https://doi.org/10.5194/bg-22-1839-2025, https://doi.org/10.5194/bg-22-1839-2025, 2025
Short summary
Short summary
Evidence shows that due to global warming, zooplankton inhabiting the coastal upwelling zone are exposed to increasing hypoxia affecting their physiology, metabolism, and population dynamics. The adaptive responses of zooplankton to cope with mild/severe hypoxia may depend on trade-offs with other metabolic/energy demands, implying less energy for growth, feeding, and reproduction, with ecological consequences for the zooplankton population and the marine food web.
Sören Iwe, Oliver Schmale, and Bernd Schneider
Biogeosciences, 22, 1767–1779, https://doi.org/10.5194/bg-22-1767-2025, https://doi.org/10.5194/bg-22-1767-2025, 2025
Short summary
Short summary
We present a novel method for quantifying N2 fixation by cyanobacteria, which is crucial in Baltic Sea eutrophication. Our Gas Equilibrium – Membrane-Inlet Mass Spectrometer (GE-MIMS), designed for operation on voluntary observing ships (VOSs), enables large-scale monitoring of surface water N2 depletion caused by N2 fixation. Laboratory tests confirm the device’s accuracy and precision, ensuring that it can complement current methods and contribute valuable data for better understanding N2 fixation in the Baltic Sea.
Yong-Woo Lee, Mi-Ok Park, Seong-Gil Kim, Tae-Hoon Kim, Yong Hwa Oh, Sang Heon Lee, and DongJoo Joung
Biogeosciences, 22, 675–690, https://doi.org/10.5194/bg-22-675-2025, https://doi.org/10.5194/bg-22-675-2025, 2025
Short summary
Short summary
Long-term pH variation in coastal waters along the Korean Peninsula was assessed for the first time, and it exhibited no significant pH change over an 11-year period. This contrasts with the ongoing pH decline in open oceans and other coastal areas. Analysis of environmental data showed that pH is mainly controlled by dissolved oxygen in bottom waters. This suggests that ocean warming could cause a pH decline in Korean coastal waters, affecting many fish and seaweed aquaculture operations.
Kadir Biçe, Tristen Myers Stewart, George G. Waldbusser, and Christof Meile
Biogeosciences, 22, 641–657, https://doi.org/10.5194/bg-22-641-2025, https://doi.org/10.5194/bg-22-641-2025, 2025
Short summary
Short summary
We studied the effect of addition of carbonate minerals on coastal sediments. We carried out laboratory experiments to quantify the dissolution kinetics and integrated these observations into a numerical model that describes biogeochemical cycling in surficial sediments. Using the model, we demonstrate the buffering effect of the mineral additions and their duration. We quantify the effect under different environmental conditions and assess the potential for increased atmospheric CO2 uptake.
Feifei Liu, Ute Daewel, Jan Kossack, Kubilay Timur Demir, Helmuth Thomas, and Corinna Schrum
EGUsphere, https://doi.org/10.5194/egusphere-2025-81, https://doi.org/10.5194/egusphere-2025-81, 2025
Short summary
Short summary
Ocean Alkalinity Enhancement boosts oceanic CO₂ absorption, offering a climate solution. Using a regional model, we examined OAE in the North Sea, revealing that shallow coastal areas achieve higher CO₂ uptake than offshore, where alkalinity is more susceptible to deep-ocean loss. Long-term carbon storage is limited, and pH shifts vary by location. Our findings guide OAE deployment to optimize carbon removal while minimizing ecological effects, supporting global climate mitigation efforts.
Jessica L. Oberlander, Mackenzie E. Burke, Cat A. London, and Hugh L. MacIntyre
Biogeosciences, 22, 499–512, https://doi.org/10.5194/bg-22-499-2025, https://doi.org/10.5194/bg-22-499-2025, 2025
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a promising negative emission technology that results in the net sequestration of atmospheric carbon. In this paper, we assess the potential impact of OAE on phytoplankton through an analysis of prior studies and the effects of simulated OAE on photosynthetic competence. Our findings suggest that there may be little if any significant impact on most phytoplankton studied to date if OAE is conducted in well-flushed, nearshore environments.
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, and Ulf Riebesell
Biogeosciences, 21, 5707–5724, https://doi.org/10.5194/bg-21-5707-2024, https://doi.org/10.5194/bg-21-5707-2024, 2024
Short summary
Short summary
This study exposed a natural community to two non-CO2-equilibrated ocean alkalinity enhancement (OAE) deployments using different minerals. Adding alkalinity in this manner decreases dissolved CO2, essential for photosynthesis. While photosynthesis was not suppressed, bloom formation was mildly delayed, potentially impacting marine food webs. The study emphasizes the need for further research on OAE without prior equilibration and on its ecological implications.
Riss M. Kell, Rebecca J. Chmiel, Deepa Rao, Dawn M. Moran, Matthew R. McIlvin, Tristan J. Horner, Nicole L. Schanke, Ichiko Sugiyama, Robert B. Dunbar, Giacomo R. DiTullio, and Mak A. Saito
Biogeosciences, 21, 5685–5706, https://doi.org/10.5194/bg-21-5685-2024, https://doi.org/10.5194/bg-21-5685-2024, 2024
Short summary
Short summary
Despite interest in modeling the biogeochemical uptake and cycling of the trace metal zinc (Zn), measurements of Zn uptake in natural marine phytoplankton communities have not been conducted previously. To fill this gap, we employed a stable isotope uptake rate measurement method to quantify Zn uptake into natural phytoplankton assemblages within the Southern Ocean. Zn demand was high and rapid enough to depress the inventory of Zn available to phytoplankton on seasonal timescales.
Luisa Chiara Meiritz, Tim Rixen, Anja Karin van der Plas, Tarron Lamont, and Niko Lahajnar
Biogeosciences, 21, 5261–5276, https://doi.org/10.5194/bg-21-5261-2024, https://doi.org/10.5194/bg-21-5261-2024, 2024
Short summary
Short summary
Moored and drifting sediment trap experiments in the northern (nBUS) and southern (sBUS) Benguela Upwelling System showed that active carbon fluxes by vertically migrating zooplankton were about 3 times higher in the sBUS than in the nBUS. Despite these large variabilities, the mean passive particulate organic carbon (POC) fluxes were almost equal in the two subsystems. The more intense near-bottom oxygen minimum layer seems to lead to higher POC fluxes and accumulation rates in the nBUS.
Michael R. Roman, Andrew H. Altieri, Denise Breitburg, Erica M. Ferrer, Natalya D. Gallo, Shin-ichi Ito, Karin Limburg, Kenneth Rose, Moriaki Yasuhara, and Lisa A. Levin
Biogeosciences, 21, 4975–5004, https://doi.org/10.5194/bg-21-4975-2024, https://doi.org/10.5194/bg-21-4975-2024, 2024
Short summary
Short summary
Oxygen-depleted ocean waters have increased worldwide. In order to improve our understanding of the impacts of this oxygen loss on marine life it is essential that we develop reliable indicators that track the negative impacts of low oxygen. We review various indicators of low-oxygen stress for marine animals including their use, research needs, and application to confront the challenges of ocean oxygen loss.
Charlotte Eich, Mathijs van Manen, J. Scott P. McCain, Loay J. Jabre, Willem H. van de Poll, Jinyoung Jung, Sven B. E. H. Pont, Hung-An Tian, Indah Ardiningsih, Gert-Jan Reichart, Erin M. Bertrand, Corina P. D. Brussaard, and Rob Middag
Biogeosciences, 21, 4637–4663, https://doi.org/10.5194/bg-21-4637-2024, https://doi.org/10.5194/bg-21-4637-2024, 2024
Short summary
Short summary
Phytoplankton growth in the Southern Ocean (SO) is often limited by low iron (Fe) concentrations. Sea surface warming impacts Fe availability and can affect phytoplankton growth. We used shipboard Fe clean incubations to test how changes in Fe and temperature affect SO phytoplankton. Their abundances usually increased with Fe addition and temperature increase, with Fe being the major factor. These findings imply potential shifts in ecosystem structure, impacting food webs and elemental cycling.
Miriam Tivig, David P. Keller, and Andreas Oschlies
Biogeosciences, 21, 4469–4493, https://doi.org/10.5194/bg-21-4469-2024, https://doi.org/10.5194/bg-21-4469-2024, 2024
Short summary
Short summary
Marine biological production is highly dependent on the availability of nitrogen and phosphorus. Rivers are the main source of phosphorus to the oceans but poorly represented in global model oceans. We include dissolved nitrogen and phosphorus from river export in a global model ocean and find that the addition of riverine phosphorus affects marine biology on millennial timescales more than riverine nitrogen alone. Globally, riverine phosphorus input increases primary production rates.
Esdoorn Willcox, Marcos Lemes, Thomas Juul-Pedersen, Mikael Kristian Sejr, Johnna Marchiano Holding, and Søren Rysgaard
Biogeosciences, 21, 4037–4050, https://doi.org/10.5194/bg-21-4037-2024, https://doi.org/10.5194/bg-21-4037-2024, 2024
Short summary
Short summary
In this work, we measured the chemistry of seawater from samples obtained from different depths and locations off the east coast of the Northeast Greenland National Park to determine what is influencing concentrations of dissolved CO2. Historically, the region has always been thought to take up CO2 from the atmosphere, but we show that it is possible for the region to become a source in late summer. We discuss the variables that may be related to such changes.
Vlad A. Macovei, Louise C. V. Rewrie, Rüdiger Röttgers, and Yoana G. Voynova
EGUsphere, https://doi.org/10.5194/egusphere-2024-2643, https://doi.org/10.5194/egusphere-2024-2643, 2024
Short summary
Short summary
A commercial vessel equipped with scientific instruments regularly travelled between two large macro-tidal estuaries. We found that biogeochemical variability in the outer estuaries is driven by the 14-day spring-neap tidal cycle, with strong effects on dissolved inorganic and organic carbon concentrations and distribution. Since this land-sea interface effect increases the strength of the carbon source to the atmosphere by 74 % during spring tide, it should be accounted for in regional models.
Lennart Thomas Bach, Aaron James Ferderer, Julie LaRoche, and Kai Georg Schulz
Biogeosciences, 21, 3665–3676, https://doi.org/10.5194/bg-21-3665-2024, https://doi.org/10.5194/bg-21-3665-2024, 2024
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.
Daniel Müller, Bo Liu, Walter Geibert, Moritz Holtappels, Lasse Sander, Elda Miramontes, Heidi Taubner, Susann Henkel, Kai-Uwe Hinrichs, Denise Bethke, Ingrid Dohrmann, and Sabine Kasten
EGUsphere, https://doi.org/10.5194/egusphere-2024-1632, https://doi.org/10.5194/egusphere-2024-1632, 2024
Short summary
Short summary
Coastal and shelf sediments are the most important sinks for organic carbon (OC) on Earth. We produced a new high-resolution sediment and pore-water dataset from the Helgoland Mud Area (HMA), North Sea, to determine, which depositional factors control the preservation of OC. The burial efficiency is highest in an area of high sedimentation and terrigenous OC. The HMA covers 0.09 % of the North Sea, but accounts for 0.76 % of its OC accumulation, highlighting the importance of the depocentre.
Deep S. Banerjee and Jozef Skakala
EGUsphere, https://doi.org/10.22541/essoar.171405637.76928549/v1, https://doi.org/10.22541/essoar.171405637.76928549/v1, 2024
Short summary
Short summary
Nitrate is a crucial nutrient in oceans. Excess nutrients can trigger uncontrolled algae growth (eutrophication), damaging marine ecosystems. We used a machine learning tool to generate a skilled, gap-free, bi-decadal surface nitrate dataset from sparse observations. This dataset reveals areas on the North West European Shelf at risk of eutrophication, bi-decadal trends in coastal nitrate, and an impact of winter nitrate on spring phytoplankton blooms.
Amanda Y. L. Cheong, Kogila Vani Annammala, Ee Ling Yong, Yongli Zhou, Robert S. Nichols, and Patrick Martin
Biogeosciences, 21, 2955–2971, https://doi.org/10.5194/bg-21-2955-2024, https://doi.org/10.5194/bg-21-2955-2024, 2024
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.
Darren Pilcher, Jessica Cross, Natalie Monacci, Linquan Mu, Kelly Kearney, Albert Hermann, and Wei Cheng
EGUsphere, https://doi.org/10.5194/egusphere-2024-1096, https://doi.org/10.5194/egusphere-2024-1096, 2024
Short summary
Short summary
The Bering Sea shelf is a highly productive marine ecosystem that is vulnerable to ocean acidification. We use a computational model to simulate the carbon cycle and acidification rates from 1970–2022. The results suggest that bottom water acidification rates are more than twice as great as surface rates. Bottom waters are also naturally more acidic, thus these waters will pass key thresholds known to negatively impact marine organisms, such as red king crab, much sooner than surface waters.
Aaron Ferderer, Kai G. Schulz, Ulf Riebesell, Kirralee G. Baker, Zanna Chase, and Lennart T. Bach
Biogeosciences, 21, 2777–2794, https://doi.org/10.5194/bg-21-2777-2024, https://doi.org/10.5194/bg-21-2777-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a promising method of atmospheric carbon removal; however, its ecological impacts remain largely unknown. We assessed the effects of simulated silicate- and calcium-based mineral OAE on diatom silicification. We found that increased silicate concentrations from silicate-based OAE increased diatom silicification. In contrast, the enhancement of alkalinity had no effect on community silicification and minimal effects on the silicification of different genera.
David González-Santana, María Segovia, Melchor González-Dávila, Librada Ramírez, Aridane G. González, Leonardo J. Pozzo-Pirotta, Veronica Arnone, Victor Vázquez, Ulf Riebesell, and J. Magdalena Santana-Casiano
Biogeosciences, 21, 2705–2715, https://doi.org/10.5194/bg-21-2705-2024, https://doi.org/10.5194/bg-21-2705-2024, 2024
Short summary
Short summary
In a recent experiment off the coast of Gran Canaria (Spain), scientists explored a method called ocean alkalinization enhancement (OAE), where carbonate minerals were added to seawater. This process changed the levels of certain ions in the water, affecting its pH and buffering capacity. The researchers were particularly interested in how this could impact the levels of essential trace metals in the water.
Lucas Porz, Wenyan Zhang, Nils Christiansen, Jan Kossack, Ute Daewel, and Corinna Schrum
Biogeosciences, 21, 2547–2570, https://doi.org/10.5194/bg-21-2547-2024, https://doi.org/10.5194/bg-21-2547-2024, 2024
Short summary
Short summary
Seafloor sediments store a large amount of carbon, helping to naturally regulate Earth's climate. If disturbed, some sediment particles can turn into CO2, but this effect is not well understood. Using computer simulations, we found that bottom-contacting fishing gears release about 1 million tons of CO2 per year in the North Sea, one of the most heavily fished regions globally. We show how protecting certain areas could reduce these emissions while also benefitting seafloor-living animals.
Jiaying A. Guo, Robert F. Strzepek, Kerrie M. Swadling, Ashley T. Townsend, and Lennart T. Bach
Biogeosciences, 21, 2335–2354, https://doi.org/10.5194/bg-21-2335-2024, https://doi.org/10.5194/bg-21-2335-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement aims to increase atmospheric CO2 sequestration by adding alkaline materials to the ocean. We assessed the environmental effects of olivine and steel slag powder on coastal plankton. Overall, slag is more efficient than olivine in releasing total alkalinity and, thus, in its ability to sequester CO2. Slag also had less environmental effect on the enclosed plankton communities when considering its higher CO2 removal potential based on this 3-week experiment.
Giovanni Galli, Sarah Wakelin, James Harle, Jason Holt, and Yuri Artioli
Biogeosciences, 21, 2143–2158, https://doi.org/10.5194/bg-21-2143-2024, https://doi.org/10.5194/bg-21-2143-2024, 2024
Short summary
Short summary
This work shows that, under a high-emission scenario, oxygen concentration in deep water of parts of the North Sea and Celtic Sea can become critically low (hypoxia) towards the end of this century. The extent and frequency of hypoxia depends on the intensity of climate change projected by different climate models. This is the result of a complex combination of factors like warming, increase in stratification, changes in the currents and changes in biological processes.
Sandy E. Tenorio and Laura Farías
Biogeosciences, 21, 2029–2050, https://doi.org/10.5194/bg-21-2029-2024, https://doi.org/10.5194/bg-21-2029-2024, 2024
Short summary
Short summary
Time series studies show that CH4 is highly dynamic on the coastal ocean surface and planktonic communities are linked to CH4 accumulation, as found in coastal upwelling off Chile. We have identified the crucial role of picoplankton (> 3 µm) in CH4 recycling, especially with the addition of methylated substrates (trimethylamine and methylphosphonic acid) during upwelling and non-upwelling periods. These insights improve understanding of surface ocean CH4 recycling, aiding CH4 emission estimates.
Charlotte A. J. Williams, Tom Hull, Jan Kaiser, Claire Mahaffey, Naomi Greenwood, Matthew Toberman, and Matthew R. Palmer
Biogeosciences, 21, 1961–1971, https://doi.org/10.5194/bg-21-1961-2024, https://doi.org/10.5194/bg-21-1961-2024, 2024
Short summary
Short summary
Oxygen (O2) is a key indicator of ocean health. The risk of O2 loss in the productive coastal/continental slope regions is increasing. Autonomous underwater vehicles equipped with O2 optodes provide lots of data but have problems resolving strong vertical O2 changes. Here we show how to overcome this and calculate how much O2 is supplied to the low-O2 bottom waters via mixing. Bursts in mixing supply nearly all of the O2 to bottom waters in autumn, stopping them reaching ecologically low levels.
Sabine Schmidt and Ibrahima Iris Diallo
Biogeosciences, 21, 1785–1800, https://doi.org/10.5194/bg-21-1785-2024, https://doi.org/10.5194/bg-21-1785-2024, 2024
Short summary
Short summary
Along the French coast facing the Bay of Biscay, the large Gironde and Loire estuaries suffer from hypoxia. This prompted a study of the small Charente estuary located between them. This work reveals a minimum oxygen zone in the Charente estuary, which extends for about 25 km. Temperature is the main factor controlling the hypoxia. This calls for the monitoring of small turbid macrotidal estuaries that are vulnerable to hypoxia, a risk expected to increase with global warming.
Simone R. Alin, Jan A. Newton, Richard A. Feely, Samantha Siedlecki, and Dana Greeley
Biogeosciences, 21, 1639–1673, https://doi.org/10.5194/bg-21-1639-2024, https://doi.org/10.5194/bg-21-1639-2024, 2024
Short summary
Short summary
We provide a new multi-stressor data product that allows us to characterize the seasonality of temperature, O2, and CO2 in the southern Salish Sea and delivers insights into the impacts of major marine heatwave and precipitation anomalies on regional ocean acidification and hypoxia. We also describe the present-day frequencies of temperature, O2, and ocean acidification conditions that cross thresholds of sensitive regional species that are economically or ecologically important.
Pamela Linford, Iván Pérez-Santos, Paulina Montero, Patricio A. Díaz, Claudia Aracena, Elías Pinilla, Facundo Barrera, Manuel Castillo, Aida Alvera-Azcárate, Mónica Alvarado, Gabriel Soto, Cécile Pujol, Camila Schwerter, Sara Arenas-Uribe, Pilar Navarro, Guido Mancilla-Gutiérrez, Robinson Altamirano, Javiera San Martín, and Camila Soto-Riquelme
Biogeosciences, 21, 1433–1459, https://doi.org/10.5194/bg-21-1433-2024, https://doi.org/10.5194/bg-21-1433-2024, 2024
Short summary
Short summary
The Patagonian fjords comprise a world region where low-oxygen water and hypoxia conditions are observed. An in situ dataset was used to quantify the mechanism involved in the presence of these conditions in northern Patagonian fjords. Water mass analysis confirmed the contribution of Equatorial Subsurface Water in the advection of the low-oxygen water, and hypoxic conditions occurred when the community respiration rate exceeded the gross primary production.
Ting Wang, Buyun Du, Inke Forbrich, Jun Zhou, Joshua Polen, Elsie M. Sunderland, Prentiss H. Balcom, Celia Chen, and Daniel Obrist
Biogeosciences, 21, 1461–1476, https://doi.org/10.5194/bg-21-1461-2024, https://doi.org/10.5194/bg-21-1461-2024, 2024
Short summary
Short summary
The strong seasonal increases of Hg in aboveground biomass during the growing season and the lack of changes observed after senescence in this salt marsh ecosystem suggest physiologically controlled Hg uptake pathways. The Hg sources found in marsh aboveground tissues originate from a mix of sources, unlike terrestrial ecosystems, where atmospheric GEM is the main source. Belowground plant tissues mostly take up Hg from soils. Overall, the salt marsh currently serves as a small net Hg sink.
Eleanor Simpson, Debby Ianson, Karen E. Kohfeld, Ana C. Franco, Paul A. Covert, Marty Davelaar, and Yves Perreault
Biogeosciences, 21, 1323–1353, https://doi.org/10.5194/bg-21-1323-2024, https://doi.org/10.5194/bg-21-1323-2024, 2024
Short summary
Short summary
Shellfish aquaculture operates in nearshore areas where data on ocean acidification parameters are limited. We show daily and seasonal variability in pH and saturation states of calcium carbonate at nearshore aquaculture sites in British Columbia, Canada, and determine the contributing drivers of this variability. We find that nearshore locations have greater variability than open waters and that the uptake of carbon by phytoplankton is the major driver of pH and saturation state variability.
S. Alejandra Castillo Cieza, Rachel H. R. Stanley, Pierre Marrec, Diana N. Fontaine, E. Taylor Crockford, Dennis J. McGillicuddy Jr., Arshia Mehta, Susanne Menden-Deuer, Emily E. Peacock, Tatiana A. Rynearson, Zoe O. Sandwith, Weifeng Zhang, and Heidi M. Sosik
Biogeosciences, 21, 1235–1257, https://doi.org/10.5194/bg-21-1235-2024, https://doi.org/10.5194/bg-21-1235-2024, 2024
Short summary
Short summary
The coastal ocean in the northeastern USA provides many services, including fisheries and habitats for threatened species. In summer 2019, a bloom occurred of a large unusual phytoplankton, the diatom Hemiaulus, with nitrogen-fixing symbionts. This led to vast changes in productivity and grazing rates in the ecosystem. This work shows that the emergence of one species can have profound effects on ecosystem function. Such changes may become more prevalent as the ocean warms due to climate change.
Claudine Hauri, Brita Irving, Sam Dupont, Rémi Pagés, Donna D. W. Hauser, and Seth L. Danielson
Biogeosciences, 21, 1135–1159, https://doi.org/10.5194/bg-21-1135-2024, https://doi.org/10.5194/bg-21-1135-2024, 2024
Short summary
Short summary
Arctic marine ecosystems are highly susceptible to impacts of climate change and ocean acidification. We present pH and pCO2 time series (2016–2020) from the Chukchi Ecosystem Observatory and analyze the drivers of the current conditions to get a better understanding of how climate change and ocean acidification could affect the ecological niches of organisms.
William Hiles, Lucy C. Miller, Craig Smeaton, and William E. N. Austin
Biogeosciences, 21, 929–948, https://doi.org/10.5194/bg-21-929-2024, https://doi.org/10.5194/bg-21-929-2024, 2024
Short summary
Short summary
Saltmarsh soils may help to limit the rate of climate change by storing carbon. To understand their impacts, they must be accurately mapped. We use drone data to estimate the size of three saltmarshes in NE Scotland. We find that drone imagery, combined with tidal data, can reliably inform our understanding of saltmarsh size. When compared with previous work using vegetation communities, we find that our most reliable new estimates of stored carbon are 15–20 % smaller than previously estimated.
De'Marcus Robinson, Anh L. D. Pham, David J. Yousavich, Felix Janssen, Frank Wenzhöfer, Eleanor C. Arrington, Kelsey M. Gosselin, Marco Sandoval-Belmar, Matthew Mar, David L. Valentine, Daniele Bianchi, and Tina Treude
Biogeosciences, 21, 773–788, https://doi.org/10.5194/bg-21-773-2024, https://doi.org/10.5194/bg-21-773-2024, 2024
Short summary
Short summary
The present study suggests that high release of ferrous iron from the seafloor of the oxygen-deficient Santa Barabara Basin (California) supports surface primary productivity, creating positive feedback on seafloor iron release by enhancing low-oxygen conditions in the basin.
David J. Yousavich, De'Marcus Robinson, Xuefeng Peng, Sebastian J. E. Krause, Frank Wenzhöfer, Felix Janssen, Na Liu, Jonathan Tarn, Franklin Kinnaman, David L. Valentine, and Tina Treude
Biogeosciences, 21, 789–809, https://doi.org/10.5194/bg-21-789-2024, https://doi.org/10.5194/bg-21-789-2024, 2024
Short summary
Short summary
Declining oxygen (O2) concentrations in coastal oceans can threaten people’s ways of life and food supplies. Here, we investigate how mats of bacteria that proliferate on the seafloor of the Santa Barbara Basin sustain and potentially worsen these O2 depletion events through their unique chemoautotrophic metabolism. Our study shows how changes in seafloor microbiology and geochemistry brought on by declining O2 concentrations can help these mats grow as well as how that growth affects the basin.
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.
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