Articles | Volume 15, issue 21
https://doi.org/10.5194/bg-15-6573-2018
© Author(s) 2018. 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-15-6573-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
07 Nov 2018
Research article |
| 07 Nov 2018
| 07 Nov 2018
Diazotrophy as the main driver of the oligotrophy gradient in the western tropical South Pacific Ocean: results from a one-dimensional biogeochemical–physical coupled model
Audrey Gimenez
CORRESPONDING AUTHOR
Aix Marseille Univ., CNRS, Université de Toulon, IRD, OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France
Melika Baklouti
CORRESPONDING AUTHOR
Aix Marseille Univ., CNRS, Université de Toulon, IRD, OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France
Thibaut Wagener
Aix Marseille Univ., CNRS, Université de Toulon, IRD, OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France
Thierry Moutin
Aix Marseille Univ., CNRS, Université de Toulon, IRD, OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France
Related authors
Thierry Moutin, Thibaut Wagener, Mathieu Caffin, Alain Fumenia, Audrey Gimenez, Melika Baklouti, Pascale Bouruet-Aubertot, Mireille Pujo-Pay, Karine Leblanc, Dominique Lefevre, Sandra Helias Nunige, Nathalie Leblond, Olivier Grosso, and Alain de Verneil
Biogeosciences, 15, 2961–2989, https://doi.org/10.5194/bg-15-2961-2018, https://doi.org/10.5194/bg-15-2961-2018, 2018
Short summary
Short summary
Surface waters of the western tropical South Pacific were sampled along a longitudinal 4000 km transect during the stratified period between the Melanesian Archipelago and the western part of the South Pacific gyre. We found a significant biological carbon pump sustained almost exclusively by N2 fixation and essentially controlled by phosphate availability in the iron-rich Melanesian Archipelago waters which appears to be a net sink for atmospheric CO2 while the gyre is in a quasi-steady state.
France Van Wambeke, Audrey Gimenez, Solange Duhamel, Cécile Dupouy, Dominique Lefevre, Mireille Pujo-Pay, and Thierry Moutin
Biogeosciences, 15, 2669–2689, https://doi.org/10.5194/bg-15-2669-2018, https://doi.org/10.5194/bg-15-2669-2018, 2018
Short summary
Short summary
The western tropical South Pacific Ocean has recently been shown to be a hotspot for biological nitrogen fixation. In this study, we examined the horizontal and vertical distribution of heterotrophic prokaryotic production alongside photosynthetic rates, nitrogen fixation rates and phosphate turnover times across the western tropical South Pacific Ocean, in order to relate these fluxes to bottom–up controls (related to nitrogen, phosphate and labile C availability).
Mathieu Caffin, Thierry Moutin, Rachel Ann Foster, Pascale Bouruet-Aubertot, Andrea Michelangelo Doglioli, Hugo Berthelot, Cécile Guieu, Olivier Grosso, Sandra Helias-Nunige, Nathalie Leblond, Audrey Gimenez, Anne Alexandra Petrenko, Alain de Verneil, and Sophie Bonnet
Biogeosciences, 15, 2565–2585, https://doi.org/10.5194/bg-15-2565-2018, https://doi.org/10.5194/bg-15-2565-2018, 2018
Short summary
Short summary
We performed N budgets to assess the role of N2 fixation on production and export in the western tropical South Pacific Ocean. We deployed a combination of techniques including high-sensitivity measurements of N input and sediment traps deployment. We demonstrated that N2 fixation was the major source of new N before atmospheric deposition and upward nitrate fluxes. It contributed significantly to organic matter export, indicating a high efficiency of this region to export carbon.
Audrey Gimenez, Melika Baklouti, Sophie Bonnet, and Thierry Moutin
Biogeosciences, 13, 5103–5120, https://doi.org/10.5194/bg-13-5103-2016, https://doi.org/10.5194/bg-13-5103-2016, 2016
Short summary
Short summary
In the context of the VAHINE mesocosm experiment in the Nouméa lagoon (New Caledonia), a 1-D vertical biogeochemical mechanistic model was used together with the in situ experiment to complement our comprehension of the planktonic ecosystem dynamics and the main biogeochemical carbon, nitrogen and phosphate fluxes. The model also showed the fate of fixed N2 by providing, over time, the proportion of diazotroph-derived nitrogen (DDN) in each compartment (mineral and organic) of the model.
Nicolas Metzl, Jonathan Fin, Claire Lo Monaco, Claude Mignon, Samir Alliouane, Bruno Bombled, Jacqueline Boutin, Yann Bozec, Steeve Comeau, Pascal Conan, Laurent Coppola, Pascale Cuet, Eva Ferreira, Jean-Pierre Gattuso, Frédéric Gazeau, Catherine Goyet, Emilie Grossteffan, Bruno Lansard, Dominique Lefèvre, Nathalie Lefèvre, Coraline Leseurre, Sébastien Petton, Mireille Pujo-Pay, Christophe Rabouille, Gilles Reverdin, Céline Ridame, Peggy Rimmelin-Maury, Jean-François Ternon, Franck Touratier, Aline Tribollet, Thibaut Wagener, and Cathy Wimart-Rousseau
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-464, https://doi.org/10.5194/essd-2024-464, 2024
Preprint under review for ESSD
Short summary
Short summary
This work presents a new synthesis of 67 000 total alkalinity and total dissolved inorganic carbon observations obtained between 1993 and 2023 in the global ocean, coastal zones and the Mediterranean Sea. We describe the data assemblage and associated quality control and discuss some potential uses of this dataset. The dataset is provided in a single format and include the quality flag for each sample.
Lucille Barré, Frédéric Diaz, Thibaut Wagener, Camille Mazoyer, Christophe Yohia, and Christel Pinazo
Geosci. Model Dev., 17, 5851–5882, https://doi.org/10.5194/gmd-17-5851-2024, https://doi.org/10.5194/gmd-17-5851-2024, 2024
Short summary
Short summary
The carbonate system is typically studied using measurements, but modeling can contribute valuable insights. Using a biogeochemical model, we propose a new representation of total alkalinity, dissolved inorganic carbon, pCO2, and pH in a highly dynamic Mediterranean coastal area, the Bay of Marseille, a useful addition to measurements. Through a detailed analysis of pCO2 and air–sea CO2 fluxes, we show that variations are strongly impacted by the hydrodynamic processes that affect the bay.
Nicolas Metzl, Jonathan Fin, Claire Lo Monaco, Claude Mignon, Samir Alliouane, David Antoine, Guillaume Bourdin, Jacqueline Boutin, Yann Bozec, Pascal Conan, Laurent Coppola, Frédéric Diaz, Eric Douville, Xavier Durrieu de Madron, Jean-Pierre Gattuso, Frédéric Gazeau, Melek Golbol, Bruno Lansard, Dominique Lefèvre, Nathalie Lefèvre, Fabien Lombard, Férial Louanchi, Liliane Merlivat, Léa Olivier, Anne Petrenko, Sébastien Petton, Mireille Pujo-Pay, Christophe Rabouille, Gilles Reverdin, Céline Ridame, Aline Tribollet, Vincenzo Vellucci, Thibaut Wagener, and Cathy Wimart-Rousseau
Earth Syst. Sci. Data, 16, 89–120, https://doi.org/10.5194/essd-16-89-2024, https://doi.org/10.5194/essd-16-89-2024, 2024
Short summary
Short summary
This work presents a synthesis of 44 000 total alkalinity and dissolved inorganic carbon observations obtained between 1993 and 2022 in the Global Ocean and the Mediterranean Sea at the surface and in the water column. Seawater samples were measured using the same method and calibrated with international Certified Reference Material. We describe the data assemblage, quality control and some potential uses of this dataset.
Lucille Barré, Frédéric Diaz, Thibaut Wagener, France Van Wambeke, Camille Mazoyer, Christophe Yohia, and Christel Pinazo
Geosci. Model Dev., 16, 6701–6739, https://doi.org/10.5194/gmd-16-6701-2023, https://doi.org/10.5194/gmd-16-6701-2023, 2023
Short summary
Short summary
While several studies have shown that mixotrophs play a crucial role in the carbon cycle, the impact of environmental forcings on their dynamics remains poorly investigated. Using a biogeochemical model that considers mixotrophs, we study the impact of light and nutrient concentration on the ecosystem composition in a highly dynamic Mediterranean coastal area: the Bay of Marseille. We show that mixotrophs cope better with oligotrophic conditions compared to strict auto- and heterotrophs.
Matthieu Bressac, Thibaut Wagener, Nathalie Leblond, Antonio Tovar-Sánchez, Céline Ridame, Vincent Taillandier, Samuel Albani, Sophie Guasco, Aurélie Dufour, Stéphanie H. M. Jacquet, François Dulac, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 18, 6435–6453, https://doi.org/10.5194/bg-18-6435-2021, https://doi.org/10.5194/bg-18-6435-2021, 2021
Short summary
Short summary
Phytoplankton growth is limited by the availability of iron in about 50 % of the ocean. Atmospheric deposition of desert dust represents a key source of iron. Here, we present direct observations of dust deposition in the Mediterranean Sea. A key finding is that the input of iron from dust primarily occurred in the deep ocean, while previous studies mainly focused on the ocean surface. This new insight will enable us to better represent controls on global marine productivity in models.
Matthieu Roy-Barman, Lorna Foliot, Eric Douville, Nathalie Leblond, Fréderic Gazeau, Matthieu Bressac, Thibaut Wagener, Céline Ridame, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 18, 2663–2678, https://doi.org/10.5194/bg-18-2663-2021, https://doi.org/10.5194/bg-18-2663-2021, 2021
Short summary
Short summary
The release of insoluble elements such as aluminum (Al), iron (Fe), rare earth elements (REEs), thorium (Th) and protactinium (Pa) when Saharan dust falls over the Mediterranean Sea was studied during tank experiments under present and future climate conditions. Each element exhibited different dissolution kinetics and dissolution fractions (always lower than a few percent). Changes in temperature and/or pH under greenhouse conditions lead to a lower Th release and a higher light REE release.
Katixa Lajaunie-Salla, Frédéric Diaz, Cathy Wimart-Rousseau, Thibaut Wagener, Dominique Lefèvre, Christophe Yohia, Irène Xueref-Remy, Brian Nathan, Alexandre Armengaud, and Christel Pinazo
Geosci. Model Dev., 14, 295–321, https://doi.org/10.5194/gmd-14-295-2021, https://doi.org/10.5194/gmd-14-295-2021, 2021
Short summary
Short summary
A biogeochemical model of planktonic food webs including a carbonate balance module is applied in the Bay of Marseille (France) to represent the carbon marine cycle expected to change in the future owing to significant increases in anthropogenic emissions of CO2. The model correctly simulates the ranges and seasonal dynamics of most variables of the carbonate system (pH). This study shows that external physical forcings have an important impact on the carbonate equilibrium in this coastal area.
Antonio Tovar-Sánchez, Araceli Rodríguez-Romero, Anja Engel, Birthe Zäncker, Franck Fu, Emilio Marañón, María Pérez-Lorenzo, Matthieu Bressac, Thibaut Wagener, Sylvain Triquet, Guillaume Siour, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 17, 2349–2364, https://doi.org/10.5194/bg-17-2349-2020, https://doi.org/10.5194/bg-17-2349-2020, 2020
Short summary
Short summary
Residence times of particulate metals derived from aerosol deposition in the Sea Surface Microlayer of the Mediterranean Sea ranged from a couple of minutes (e.g., for Fe) to a few hours (e.g., for Cu). Microbial activity seems to play an important role in in this process and in the concentration and distribution of metals between diferent water layers.
Thierry Moutin
Biogeosciences, 16, 1673–1673, https://doi.org/10.5194/bg-16-1673-2019, https://doi.org/10.5194/bg-16-1673-2019, 2019
Pascale Bouruet-Aubertot, Yannis Cuypers, Andrea Doglioli, Mathieu Caffin, Christophe Yohia, Alain de Verneil, Anne Petrenko, Dominique Lefèvre, Hervé Le Goff, Gilles Rougier, Marc Picheral, and Thierry Moutin
Biogeosciences, 15, 7485–7504, https://doi.org/10.5194/bg-15-7485-2018, https://doi.org/10.5194/bg-15-7485-2018, 2018
Short summary
Short summary
The OUTPACE cruise took place between New Caledonia and French Polynesia. The main purpose was to understand how micro-organisms can survive in a very poor environment. One main source of nutrients is at depth, below the euphotic layer where micro-organisms live. The purpose of the turbulence measurements was to determine to which extent turbulence may
upliftnutrients into the euphotic layer. The origin of the turbulence that was found contrasted along the transect was also determined.
Thibaut Wagener, Nicolas Metzl, Mathieu Caffin, Jonathan Fin, Sandra Helias Nunige, Dominique Lefevre, Claire Lo Monaco, Gilles Rougier, and Thierry Moutin
Biogeosciences, 15, 5221–5236, https://doi.org/10.5194/bg-15-5221-2018, https://doi.org/10.5194/bg-15-5221-2018, 2018
Short summary
Short summary
The western tropical South Pacific was sampled along a longitudinal 4000 km transect (OUTPACE cruise) for the measurement of carbonate parameters (total alkalinity and total inorganic carbon) between the Melanesian Archipelago and the western part of the South Pacific gyre. This paper reports this new dataset and derived properties. We also estimate anthropogenic carbon distribution in the water column using the TrOCA method.
Thierry Moutin, Thibaut Wagener, Mathieu Caffin, Alain Fumenia, Audrey Gimenez, Melika Baklouti, Pascale Bouruet-Aubertot, Mireille Pujo-Pay, Karine Leblanc, Dominique Lefevre, Sandra Helias Nunige, Nathalie Leblond, Olivier Grosso, and Alain de Verneil
Biogeosciences, 15, 2961–2989, https://doi.org/10.5194/bg-15-2961-2018, https://doi.org/10.5194/bg-15-2961-2018, 2018
Short summary
Short summary
Surface waters of the western tropical South Pacific were sampled along a longitudinal 4000 km transect during the stratified period between the Melanesian Archipelago and the western part of the South Pacific gyre. We found a significant biological carbon pump sustained almost exclusively by N2 fixation and essentially controlled by phosphate availability in the iron-rich Melanesian Archipelago waters which appears to be a net sink for atmospheric CO2 while the gyre is in a quasi-steady state.
France Van Wambeke, Audrey Gimenez, Solange Duhamel, Cécile Dupouy, Dominique Lefevre, Mireille Pujo-Pay, and Thierry Moutin
Biogeosciences, 15, 2669–2689, https://doi.org/10.5194/bg-15-2669-2018, https://doi.org/10.5194/bg-15-2669-2018, 2018
Short summary
Short summary
The western tropical South Pacific Ocean has recently been shown to be a hotspot for biological nitrogen fixation. In this study, we examined the horizontal and vertical distribution of heterotrophic prokaryotic production alongside photosynthetic rates, nitrogen fixation rates and phosphate turnover times across the western tropical South Pacific Ocean, in order to relate these fluxes to bottom–up controls (related to nitrogen, phosphate and labile C availability).
Angela N. Knapp, Kelly M. McCabe, Olivier Grosso, Nathalie Leblond, Thierry Moutin, and Sophie Bonnet
Biogeosciences, 15, 2619–2628, https://doi.org/10.5194/bg-15-2619-2018, https://doi.org/10.5194/bg-15-2619-2018, 2018
Short summary
Short summary
The spatial distribution of biological N2 fixation fluxes to the ocean remains poorly constrained. Here we use nitrogen isotope budgets to identify significant N2 fixation inputs to the western tropical South Pacific (WTSP), where N2 fixation supports > 50 % of export production at stations proximal to iron sources. The significant N2 fixation inputs in the WTSP may offset nitrogen loss in the oxygen-deficient zones of the eastern tropical South Pacific.
Mathieu Caffin, Thierry Moutin, Rachel Ann Foster, Pascale Bouruet-Aubertot, Andrea Michelangelo Doglioli, Hugo Berthelot, Cécile Guieu, Olivier Grosso, Sandra Helias-Nunige, Nathalie Leblond, Audrey Gimenez, Anne Alexandra Petrenko, Alain de Verneil, and Sophie Bonnet
Biogeosciences, 15, 2565–2585, https://doi.org/10.5194/bg-15-2565-2018, https://doi.org/10.5194/bg-15-2565-2018, 2018
Short summary
Short summary
We performed N budgets to assess the role of N2 fixation on production and export in the western tropical South Pacific Ocean. We deployed a combination of techniques including high-sensitivity measurements of N input and sediment traps deployment. We demonstrated that N2 fixation was the major source of new N before atmospheric deposition and upward nitrate fluxes. It contributed significantly to organic matter export, indicating a high efficiency of this region to export carbon.
Alain de Verneil, Louise Rousselet, Andrea M. Doglioli, Anne A. Petrenko, Christophe Maes, Pascale Bouruet-Aubertot, and Thierry Moutin
Biogeosciences, 15, 2125–2147, https://doi.org/10.5194/bg-15-2125-2018, https://doi.org/10.5194/bg-15-2125-2018, 2018
Short summary
Short summary
Oceanographic campaigns to measure biogeochemical processes popularly deploy drifters with onboard incubations to stay in a single body of water. Here, we aggregate physical data taken during such a cruise, OUTPACE, to independently test in a new approach whether the drifter really stayed in what can be considered a single biological or chemical environment. This study concludes that future campaigns would benefit from similar data collection and analysis to validate their sampling strategy.
Vincent Taillandier, Thibaut Wagener, Fabrizio D'Ortenzio, Nicolas Mayot, Hervé Legoff, Joséphine Ras, Laurent Coppola, Orens Pasqueron de Fommervault, Catherine Schmechtig, Emilie Diamond, Henry Bittig, Dominique Lefevre, Edouard Leymarie, Antoine Poteau, and Louis Prieur
Earth Syst. Sci. Data, 10, 627–641, https://doi.org/10.5194/essd-10-627-2018, https://doi.org/10.5194/essd-10-627-2018, 2018
Short summary
Short summary
We report on data from an oceanographic cruise, covering western, central and eastern parts of the Mediterranean Sea. This cruise was fully dedicated to the maintenance and the metrological verification of a biogeochemical observing system based on a fleet of BGC-Argo floats.
Pierre Marrec, Gérald Grégori, Andrea M. Doglioli, Mathilde Dugenne, Alice Della Penna, Nagib Bhairy, Thierry Cariou, Sandra Hélias Nunige, Soumaya Lahbib, Gilles Rougier, Thibaut Wagener, and Melilotus Thyssen
Biogeosciences, 15, 1579–1606, https://doi.org/10.5194/bg-15-1579-2018, https://doi.org/10.5194/bg-15-1579-2018, 2018
Short summary
Short summary
The objective of this study was to better understand the variability of the phytoplankton community structure in small physical structures at the surface of the ocean. After identifying such a structure in the Mediterranean Sea, we deployed cutting-edge physical and biological sensors in order to observe at a high frequency the dynamics of this structure. From these observations we described the variations of the phytoplankton community structure and how the physics controls this variability.
Alain Fumenia, Thierry Moutin, Sophie Bonnet, Mar Benavides, Anne Petrenko, Sandra Helias Nunige, and Christophe Maes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-557, https://doi.org/10.5194/bg-2017-557, 2018
Revised manuscript not accepted
Short summary
Short summary
The Melanesian archipelago waters between 160° E and 170° W are characterized by a significant N2 fixation rates and an excess of particulate organic nitrogen compared to the canonical ratio of Redfield and a positive N*. We hypothesize that the southern branch of the subtropical gyre is probably the main vector of excess nitrogen transport in the thermocline waters showing an influence of nitrogen fixation occurring in the western tropical in a large part of the South Pacific.
Alain de Verneil, Louise Rousselet, Andrea M. Doglioli, Anne A. Petrenko, and Thierry Moutin
Biogeosciences, 14, 3471–3486, https://doi.org/10.5194/bg-14-3471-2017, https://doi.org/10.5194/bg-14-3471-2017, 2017
Short summary
Short summary
A surface summer plankton bloom in the western tropical South Pacific was sampled during the Oligotrophy to UlTra-oligotrophy PACific Experiment (OUTPACE) cruise. We characterize the bloom's properties and the circulation responsible for its evolution. Nitrogen fixation helped sustain the bloom, and larger-scale flows, rather than the smaller ones, explain its movements. Future studies of blooms in this region can make use of these findings to track the horizontal export of plankton production.
Thierry Moutin, Andrea Michelangelo Doglioli, Alain de Verneil, and Sophie Bonnet
Biogeosciences, 14, 3207–3220, https://doi.org/10.5194/bg-14-3207-2017, https://doi.org/10.5194/bg-14-3207-2017, 2017
Short summary
Short summary
The overall goal of OUTPACE was to obtain a successful representation of the interactions between planktonic organisms and the cycle of biogenic elements in the western tropical South Pacific Ocean across trophic and N2 fixation gradients. The international OUTPACE cruise took place between 18 February and 3 April 2015 aboard the RV L’Atalante and involved 60 scientists. The transect covered ~4 000 km from the western part of the Melanesian archipelago to the western boundary of the gyre.
Audrey Gimenez, Melika Baklouti, Sophie Bonnet, and Thierry Moutin
Biogeosciences, 13, 5103–5120, https://doi.org/10.5194/bg-13-5103-2016, https://doi.org/10.5194/bg-13-5103-2016, 2016
Short summary
Short summary
In the context of the VAHINE mesocosm experiment in the Nouméa lagoon (New Caledonia), a 1-D vertical biogeochemical mechanistic model was used together with the in situ experiment to complement our comprehension of the planktonic ecosystem dynamics and the main biogeochemical carbon, nitrogen and phosphate fluxes. The model also showed the fate of fixed N2 by providing, over time, the proportion of diazotroph-derived nitrogen (DDN) in each compartment (mineral and organic) of the model.
Angela N. Knapp, Sarah E. Fawcett, Alfredo Martínez-Garcia, Nathalie Leblond, Thierry Moutin, and Sophie Bonnet
Biogeosciences, 13, 4645–4657, https://doi.org/10.5194/bg-13-4645-2016, https://doi.org/10.5194/bg-13-4645-2016, 2016
Short summary
Short summary
The goal of this manuscript was to track the fate of newly fixed nitrogen (N) in large volume mesocosms in the coastal waters of New Caledonia. We used a N isotope ("δ15N") budget and found a shift in the δ15N of sinking particulate N over the 23-day experiment, indicating that nitrate supported export production at the beginning of the experiment, but that nitrogen fixation supported export at the end. We infer that nitrogen fixation supported export production by a release of dissolved N.
Ilana Berman-Frank, Dina Spungin, Eyal Rahav, France Van Wambeke, Kendra Turk-Kubo, and Thierry Moutin
Biogeosciences, 13, 3793–3805, https://doi.org/10.5194/bg-13-3793-2016, https://doi.org/10.5194/bg-13-3793-2016, 2016
Short summary
Short summary
In the marine environment, sticky sugar-containing gels, termed transparent exopolymeric particles (TEP), are produced from biological sources and physical and chemical processes. These compounds are essential vectors enhancing downward flow of organic matter and its storage at depth. Spatial and temporal dynamics of TEPs were followed for 23 days during the VAHINE mesocosm experiment that investigated the fate of nitrogen and carbon derived from organisms fixing atmospheric N2 (diazotrophs).
France Van Wambeke, Ulrike Pfreundt, Aude Barani, Hugo Berthelot, Thierry Moutin, Martine Rodier, Wolfgang R. Hess, and Sophie Bonnet
Biogeosciences, 13, 3187–3202, https://doi.org/10.5194/bg-13-3187-2016, https://doi.org/10.5194/bg-13-3187-2016, 2016
Short summary
Short summary
The phytoplankton is at the base of the plankton food web in large parts of oceanic "deserts" such as the South Pacific Ocean, where nitrogen sources limit activity. Mesocosms were fertilized with phosphorus to stimulate diazotrophy (atmospheric N2 fixation). Mostly diazotroph-derived nitrogen fuelled the heterotrophic bacterial community through indirect processes generating dissolved organic matter and detritus, such as mortality, lysis and grazing of both diazotrophs and non-diazotrophs.
Sophie Bonnet, Thierry Moutin, Martine Rodier, Jean-Michel Grisoni, Francis Louis, Eric Folcher, Bertrand Bourgeois, Jean-Michel Boré, and Armelle Renaud
Biogeosciences, 13, 2803–2814, https://doi.org/10.5194/bg-13-2803-2016, https://doi.org/10.5194/bg-13-2803-2016, 2016
Short summary
Short summary
e main goal of the VAHINE project was to study the fate of N2 fixation in the ocean. Three large-volume (~ 50 m3) mesocosms were deployed in a tropical oligotrophic ecosystem (the New Caledonia lagoon, south-eastern Pacific). This introductory paper describes the scientific objectives of the project in detail as well as the implementation plan: the mesocosm description and deployment, the selection of the study site, and the logistical and sampling strategy.
A. Guyennon, M. Baklouti, F. Diaz, J. Palmieri, J. Beuvier, C. Lebaupin-Brossier, T. Arsouze, K. Béranger, J.-C. Dutay, and T. Moutin
Biogeosciences, 12, 7025–7046, https://doi.org/10.5194/bg-12-7025-2015, https://doi.org/10.5194/bg-12-7025-2015, 2015
Short summary
Short summary
Dissolved organic carbon (DOC) has already been identified as a potentially significant source of carbon export in the Mediterranean Sea, though in situ export estimations are scarce. This work provides a thorough analysis at basin scale of carbon export with the coupled model NEMO-MED12/Eco3M-MED model. The seasonality and the processes of particulate and dissolved carbon production are also investigated. DOC export appears to be dominant in most regions, especially in the eastern basin.
H. Berthelot, T. Moutin, S. L'Helguen, K. Leblanc, S. Hélias, O. Grosso, N. Leblond, B. Charrière, and S. Bonnet
Biogeosciences, 12, 4099–4112, https://doi.org/10.5194/bg-12-4099-2015, https://doi.org/10.5194/bg-12-4099-2015, 2015
A. Talarmin, F. Van Wambeke, P. Lebaron, and T. Moutin
Biogeosciences, 12, 1237–1247, https://doi.org/10.5194/bg-12-1237-2015, https://doi.org/10.5194/bg-12-1237-2015, 2015
Short summary
Short summary
Along a transect in the warm nutrient-depleted Mediterranean Sea, we found that microorganisms shared phosphate resources by using different uptake strategies. Heterotrophic prokaryotes dominated phosphate uptake in the upper layers while cyanobacteria dominated uptake fluxes around the deep chlorophyll maximum depth. Synechococcus seemed well equipped to respond to pulses of phosphate, whereas Prochlorococcus and heterotrophs were more adapted to very low concentrations.
K. Desboeufs, N. Leblond, T. Wagener, E. Bon Nguyen, and C. Guieu
Biogeosciences, 11, 5581–5594, https://doi.org/10.5194/bg-11-5581-2014, https://doi.org/10.5194/bg-11-5581-2014, 2014
Related subject area
Biogeochemistry: Modelling, Aquatic
Global impact of benthic denitrification on marine N2 fixation and primary production simulated by a variable-stoichiometry Earth system model
Killing the predator: impacts of highest-predator mortality on the global-ocean ecosystem structure
Hydrodynamic and biochemical impacts on the development of hypoxia in the Louisiana–Texas shelf – Part 1: roles of nutrient limitation and plankton community
Changes in Arctic Ocean plankton community structure and trophic dynamics on seasonal to interannual timescales
Validation of the coupled physical–biogeochemical ocean model NEMO–SCOBI for the North Sea–Baltic Sea system
Investigating ecosystem connections in the shelf sea environment using complex networks
Seasonal and interannual variability of the pelagic ecosystem and of the organic carbon budget in the Rhodes Gyre (eastern Mediterranean): influence of winter mixing
How much do bacterial growth properties and biodegradable dissolved organic matter control water quality at low flow?
Methane emissions from Arctic landscapes during 2000–2015: an analysis with land and lake biogeochemistry models
Including filter-feeding gelatinous macrozooplankton in a global marine biogeochemical model: model–data comparison and impact on the ocean carbon cycle
Riverine impact on future projections of marine primary production and carbon uptake
Subsurface oxygen maximum in oligotrophic marine ecosystems: mapping the interaction between physical and biogeochemical processes
Quantifying biological carbon pump pathways with a data-constrained mechanistic model ensemble approach
Assessing the spatial and temporal variability of methylmercury biogeochemistry and bioaccumulation in the Mediterranean Sea with a coupled 3D model
Hydrodynamic and biochemical impacts on the development of hypoxia in the Louisiana–Texas shelf – Part 2: statistical modeling and hypoxia prediction
Modelling the effects of benthic fauna on carbon, nitrogen and phosphorus dynamics in the Baltic Sea
Improved prediction of dimethyl sulfide (DMS) distributions in the northeast subarctic Pacific using machine-learning algorithms
Nutrient transport and transformation in macrotidal estuaries of the French Atlantic coast: a modeling approach using the Carbon-Generic Estuarine Model
A modelling study of temporal and spatial pCO2 variability on the biologically active and temperature-dominated Scotian Shelf
Modeling the marine chromium cycle: new constraints on global-scale processes
New insights into large-scale trends of apparent organic matter reactivity in marine sediments and patterns of benthic carbon transformation
Evaluation of ocean dimethylsulfide concentration and emission in CMIP6 models
Zooplankton mortality effects on the plankton community of the northern Humboldt Current System: sensitivity of a regional biogeochemical model
Multi-compartment kinetic–allometric (MCKA) model of radionuclide bioaccumulation in marine fish
Impact of bottom trawling on sediment biogeochemistry: a modelling approach
Cyanobacteria blooms in the Baltic Sea: a review of models and facts
Arctic Ocean acidification over the 21st century co-driven by anthropogenic carbon increases and freshening in the CMIP6 model ensemble
Modeling silicate–nitrate–ammonium co-limitation of algal growth and the importance of bacterial remineralization based on an experimental Arctic coastal spring bloom culture study
Role of jellyfish in the plankton ecosystem revealed using a global ocean biogeochemical model
Extreme event waves in marine ecosystems: an application to Mediterranean Sea surface chlorophyll
Use of optical absorption indices to assess seasonal variability of dissolved organic matter in Amazon floodplain lakes
The role of sediment-induced light attenuation on primary production during Hurricane Gustav (2008)
Quantifying spatiotemporal variability in zooplankton dynamics in the Gulf of Mexico with a physical–biogeochemical model
One size fits all? Calibrating an ocean biogeochemistry model for different circulations
Assessing the temporal scale of deep-sea mining impacts on sediment biogeochemistry
Seasonal patterns of surface inorganic carbon system variables in the Gulf of Mexico inferred from a regional high-resolution ocean biogeochemical model
Oxygen dynamics and evaluation of the single-station diel oxygen model across contrasting geologies
Oceanic CO2 outgassing and biological production hotspots induced by pre-industrial river loads of nutrients and carbon in a global modeling approach
Global trends in marine nitrate N isotopes from observations and a neural network-based climatology
Merging bio-optical data from Biogeochemical-Argo floats and models in marine biogeochemistry
Model constraints on the anthropogenic carbon budget of the Arctic Ocean
Modeling oceanic nitrate and nitrite concentrations and isotopes using a 3-D inverse N cycle model
Biogeochemical response of the Mediterranean Sea to the transient SRES-A2 climate change scenario
Modelling the biogeochemical effects of heterotrophic and autotrophic N2 fixation in the Gulf of Aqaba (Israel), Red Sea
A perturbed biogeochemistry model ensemble evaluated against in situ and satellite observations
Causes of simulated long-term changes in phytoplankton biomass in the Baltic proper: a wavelet analysis
Modelling N2 fixation related to Trichodesmium sp.: driving processes and impacts on primary production in the tropical Pacific Ocean
Long-term response of oceanic carbon uptake to global warming via physical and biological pumps
Seasonal patterns in phytoplankton biomass across the northern and deep Gulf of Mexico: a numerical model study
Sea-surface dimethylsulfide (DMS) concentration from satellite data at global and regional scales
Na Li, Christopher J. Somes, Angela Landolfi, Chia-Te Chien, Markus Pahlow, and Andreas Oschlies
Biogeosciences, 21, 4361–4380, https://doi.org/10.5194/bg-21-4361-2024, https://doi.org/10.5194/bg-21-4361-2024, 2024
Short summary
Short summary
N is a crucial nutrient that limits phytoplankton growth in large ocean areas. The amount of oceanic N is governed by the balance of N2 fixation and denitrification. Here we incorporate benthic denitrification into an Earth system model with variable particulate stoichiometry. Our model compares better to the observed surface nutrient distributions, marine N2 fixation, and primary production. Benthic denitrification plays an important role in marine N and C cycling and hence the global climate.
David Talmy, Eric Carr, Harshana Rajakaruna, Selina Våge, and Anne Willem Omta
Biogeosciences, 21, 2493–2507, https://doi.org/10.5194/bg-21-2493-2024, https://doi.org/10.5194/bg-21-2493-2024, 2024
Short summary
Short summary
The structure of plankton communities is central to global cycles of carbon, nitrogen, and other elements. This study explored the sensitivity of different assumptions about highest-predator mortality in ecosystem models with contrasting food web structures. In the context of environmental data, we find support for models assuming a density-dependent mortality of the highest predator, irrespective of assumed food web structure.
Yanda Ou and Z. George Xue
Biogeosciences, 21, 2385–2424, https://doi.org/10.5194/bg-21-2385-2024, https://doi.org/10.5194/bg-21-2385-2024, 2024
Short summary
Short summary
Developed for the Gulf of Mexico (2006–2020), a 3D hydrodynamic–biogeochemical model validated against in situ data reveals the impact of nutrients and plankton diversity on dissolved oxygen dynamics. It highlights the role of physical processes, sediment oxygen consumption, and nutrient distribution in shaping bottom oxygen levels and hypoxia. The model underscores the importance of complex plankton interactions for understanding primary production and hypoxia evolution.
Gabriela Negrete-García, Jessica Y. Luo, Colleen M. Petrik, Manfredi Manizza, and Andrew D. Barton
EGUsphere, https://doi.org/10.5194/egusphere-2024-953, https://doi.org/10.5194/egusphere-2024-953, 2024
Short summary
Short summary
The Arctic Ocean experiences significant seasonal and year-to-year changes, impacting marine plankton populations. Using a plankton community model, we studied these effects on plankton communities and their influence on fish production. Our findings revealed earlier plankton blooms, shifts towards more carnivorous zooplankton, and increased fisheries potential during summertime, especially in warmer years with less ice, highlighting the delicate balance of Arctic ecosystems.
Itzel Ruvalcaba Baroni, Elin Almroth-Rosell, Lars Axell, Sam T. Fredriksson, Jenny Hieronymus, Magnus Hieronymus, Sandra-Esther Brunnabend, Matthias Gröger, Ivan Kuznetsov, Filippa Fransner, Robinson Hordoir, Saeed Falahat, and Lars Arneborg
Biogeosciences, 21, 2087–2132, https://doi.org/10.5194/bg-21-2087-2024, https://doi.org/10.5194/bg-21-2087-2024, 2024
Short summary
Short summary
The health of the Baltic and North seas is threatened due to high anthropogenic pressure; thus, different methods to assess the status of these regions are urgently needed. Here, we validated a novel model simulating the ocean dynamics and biogeochemistry of the Baltic and North seas that can be used to create future climate and nutrient scenarios, contribute to European initiatives on de-eutrophication, and provide water quality advice and support on nutrient load reductions for both seas.
Ieuan Higgs, Jozef Skákala, Ross Bannister, Alberto Carrassi, and Stefano Ciavatta
Biogeosciences, 21, 731–746, https://doi.org/10.5194/bg-21-731-2024, https://doi.org/10.5194/bg-21-731-2024, 2024
Short summary
Short summary
A complex network is a way of representing which parts of a system are connected to other parts. We have constructed a complex network based on an ecosystem–ocean model. From this, we can identify patterns in the structure and areas of similar behaviour. This can help to understand how natural, or human-made, changes will affect the shelf sea ecosystem, and it can be used in multiple future applications such as improving modelling, data assimilation, or machine learning.
Joelle Habib, Caroline Ulses, Claude Estournel, Milad Fakhri, Patrick Marsaleix, Mireille Pujo-Pay, Marine Fourrier, Laurent Coppola, Alexandre Mignot, Laurent Mortier, and Pascal Conan
Biogeosciences, 20, 3203–3228, https://doi.org/10.5194/bg-20-3203-2023, https://doi.org/10.5194/bg-20-3203-2023, 2023
Short summary
Short summary
The Rhodes Gyre, eastern Mediterranean Sea, is the main Levantine Intermediate Water formation site. In this study, we use a 3D physical–biogeochemical model to investigate the seasonal and interannual variability of organic carbon dynamics in the gyre. Our results show its autotrophic nature and its high interannual variability, with enhanced primary production, downward exports, and onward exports to the surrounding regions during years marked by intense heat losses and deep mixed layers.
Masihullah Hasanyar, Thomas Romary, Shuaitao Wang, and Nicolas Flipo
Biogeosciences, 20, 1621–1633, https://doi.org/10.5194/bg-20-1621-2023, https://doi.org/10.5194/bg-20-1621-2023, 2023
Short summary
Short summary
The results of this study indicate that biodegradable dissolved organic matter is responsible for oxygen depletion at low flow during summer seasons when heterotrophic bacterial activity is so intense. Therefore, the dissolved organic matter must be well measured in the water monitoring networks in order to have more accurate water quality models. It also advocates for high-frequency data collection for better quantification of the uncertainties related to organic matter.
Xiangyu Liu and Qianlai Zhuang
Biogeosciences, 20, 1181–1193, https://doi.org/10.5194/bg-20-1181-2023, https://doi.org/10.5194/bg-20-1181-2023, 2023
Short summary
Short summary
We are among the first to quantify methane emissions from inland water system in the pan-Arctic. The total CH4 emissions are 36.46 Tg CH4 yr−1 during 2000–2015, of which wetlands and lakes were 21.69 Tg yr−1 and 14.76 Tg yr−1, respectively. By using two non-overlap area change datasets with land and lake models, our simulation avoids small lakes being counted twice as both lake and wetland, and it narrows the gap between two different methods used to quantify regional CH4 emissions.
Corentin Clerc, Laurent Bopp, Fabio Benedetti, Meike Vogt, and Olivier Aumont
Biogeosciences, 20, 869–895, https://doi.org/10.5194/bg-20-869-2023, https://doi.org/10.5194/bg-20-869-2023, 2023
Short summary
Short summary
Gelatinous zooplankton play a key role in the ocean carbon cycle. In particular, pelagic tunicates, which feed on a wide size range of prey, produce rapidly sinking detritus. Thus, they efficiently transfer carbon from the surface to the depths. Consequently, we added these organisms to a marine biogeochemical model (PISCES-v2) and evaluated their impact on the global carbon cycle. We found that they contribute significantly to carbon export and that this contribution increases with depth.
Shuang Gao, Jörg Schwinger, Jerry Tjiputra, Ingo Bethke, Jens Hartmann, Emilio Mayorga, and Christoph Heinze
Biogeosciences, 20, 93–119, https://doi.org/10.5194/bg-20-93-2023, https://doi.org/10.5194/bg-20-93-2023, 2023
Short summary
Short summary
We assess the impact of riverine nutrients and carbon (C) on projected marine primary production (PP) and C uptake using a fully coupled Earth system model. Riverine inputs alleviate nutrient limitation and thus lessen the projected PP decline by up to 0.7 Pg C yr−1 globally. The effect of increased riverine C may be larger than the effect of nutrient inputs in the future on the projected ocean C uptake, while in the historical period increased nutrient inputs are considered the largest driver.
Valeria Di Biagio, Stefano Salon, Laura Feudale, and Gianpiero Cossarini
Biogeosciences, 19, 5553–5574, https://doi.org/10.5194/bg-19-5553-2022, https://doi.org/10.5194/bg-19-5553-2022, 2022
Short summary
Short summary
The amount of dissolved oxygen in the ocean is the result of interacting physical and biological processes. Oxygen vertical profiles show a subsurface maximum in a large part of the ocean. We used a numerical model to map this subsurface maximum in the Mediterranean Sea and to link local differences in its properties to the driving processes. This emerging feature can help the marine ecosystem functioning to be better understood, also under the impacts of climate change.
Michael R. Stukel, Moira Décima, and Michael R. Landry
Biogeosciences, 19, 3595–3624, https://doi.org/10.5194/bg-19-3595-2022, https://doi.org/10.5194/bg-19-3595-2022, 2022
Short summary
Short summary
The biological carbon pump (BCP) transports carbon into the deep ocean, leading to long-term marine carbon sequestration. It is driven by many physical, chemical, and ecological processes. We developed a model of the BCP constrained using data from 11 cruises in 4 different ocean regions. Our results show that sinking particles and vertical mixing are more important than transport mediated by vertically migrating zooplankton. They also highlight the uncertainty in current estimates of the BCP.
Ginevra Rosati, Donata Canu, Paolo Lazzari, and Cosimo Solidoro
Biogeosciences, 19, 3663–3682, https://doi.org/10.5194/bg-19-3663-2022, https://doi.org/10.5194/bg-19-3663-2022, 2022
Short summary
Short summary
Methylmercury (MeHg) is produced and bioaccumulated in marine food webs, posing concerns for human exposure through seafood consumption. We modeled and analyzed the fate of MeHg in the lower food web of the Mediterranean Sea. The modeled spatial–temporal distribution of plankton bioaccumulation differs from the distribution of MeHg in surface water. We also show that MeHg exposure concentrations in temperate waters can be lowered by winter convection, which is declining due to climate change.
Yanda Ou, Bin Li, and Z. George Xue
Biogeosciences, 19, 3575–3593, https://doi.org/10.5194/bg-19-3575-2022, https://doi.org/10.5194/bg-19-3575-2022, 2022
Short summary
Short summary
Over the past decades, the Louisiana–Texas shelf has been suffering recurring hypoxia (dissolved oxygen < 2 mg L−1). We developed a novel prediction model using state-of-the-art statistical techniques based on physical and biogeochemical data provided by a numerical model. The model can capture both the magnitude and onset of the annual hypoxia events. This study also demonstrates that it is possible to use a global model forecast to predict regional ocean water quality.
Eva Ehrnsten, Oleg Pavlovitch Savchuk, and Bo Gustav Gustafsson
Biogeosciences, 19, 3337–3367, https://doi.org/10.5194/bg-19-3337-2022, https://doi.org/10.5194/bg-19-3337-2022, 2022
Short summary
Short summary
We studied the effects of benthic fauna, animals living on or in the seafloor, on the biogeochemical cycles of carbon, nitrogen and phosphorus using a model of the Baltic Sea ecosystem. By eating and excreting, the animals transform a large part of organic matter sinking to the seafloor into inorganic forms, which fuel plankton blooms. Simultaneously, when they move around (bioturbate), phosphorus is bound in the sediments. This reduces nitrogen-fixing plankton blooms and oxygen depletion.
Brandon J. McNabb and Philippe D. Tortell
Biogeosciences, 19, 1705–1721, https://doi.org/10.5194/bg-19-1705-2022, https://doi.org/10.5194/bg-19-1705-2022, 2022
Short summary
Short summary
The trace gas dimethyl sulfide (DMS) plays an important role in the ocean sulfur cycle and can also influence Earth’s climate. Our study used two statistical methods to predict surface ocean concentrations and rates of sea–air exchange of DMS in the northeast subarctic Pacific. Our results show improved predictive power over previous approaches and suggest that nutrient availability, light-dependent processes, and physical mixing may be important controls on DMS in this region.
Xi Wei, Josette Garnier, Vincent Thieu, Paul Passy, Romain Le Gendre, Gilles Billen, Maia Akopian, and Goulven Gildas Laruelle
Biogeosciences, 19, 931–955, https://doi.org/10.5194/bg-19-931-2022, https://doi.org/10.5194/bg-19-931-2022, 2022
Short summary
Short summary
Estuaries are key reactive ecosystems along the land–ocean aquatic continuum and are often strongly impacted by anthropogenic activities. We calculated nutrient in and out fluxes by using a 1-D transient model for seven estuaries along the French Atlantic coast. Among these, large estuaries with high residence times showed higher retention rates than medium and small ones. All reveal coastal eutrophication due to the excess of diffused nitrogen from intensive agricultural river basins.
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.
Frerk Pöppelmeier, David J. Janssen, Samuel L. Jaccard, and Thomas F. Stocker
Biogeosciences, 18, 5447–5463, https://doi.org/10.5194/bg-18-5447-2021, https://doi.org/10.5194/bg-18-5447-2021, 2021
Short summary
Short summary
Chromium (Cr) is a redox-sensitive element that holds promise as a tracer of ocean oxygenation and biological activity. We here implemented the oxidation states Cr(III) and Cr(VI) in the Bern3D model to investigate the processes that shape the global Cr distribution. We find a Cr ocean residence time of 5–8 kyr and that the benthic source dominates the tracer budget. Further, regional model–data mismatches suggest strong Cr removal in oxygen minimum zones and a spatially variable benthic source.
Felipe S. Freitas, Philip A. Pika, Sabine Kasten, Bo B. Jørgensen, Jens Rassmann, Christophe Rabouille, Shaun Thomas, Henrik Sass, Richard D. Pancost, and Sandra Arndt
Biogeosciences, 18, 4651–4679, https://doi.org/10.5194/bg-18-4651-2021, https://doi.org/10.5194/bg-18-4651-2021, 2021
Short summary
Short summary
It remains challenging to fully understand what controls carbon burial in marine sediments globally. Thus, we use a model–data approach to identify patterns of organic matter reactivity at the seafloor across distinct environmental conditions. Our findings support the notion that organic matter reactivity is a dynamic ecosystem property and strongly influences biogeochemical cycling and exchange. Our results are essential to improve predictions of future changes in carbon cycling and climate.
Josué Bock, Martine Michou, Pierre Nabat, Manabu Abe, Jane P. Mulcahy, Dirk J. L. Olivié, Jörg Schwinger, Parvadha Suntharalingam, Jerry Tjiputra, Marco van Hulten, Michio Watanabe, Andrew Yool, and Roland Séférian
Biogeosciences, 18, 3823–3860, https://doi.org/10.5194/bg-18-3823-2021, https://doi.org/10.5194/bg-18-3823-2021, 2021
Short summary
Short summary
In this study we analyse surface ocean dimethylsulfide (DMS) concentration and flux to the atmosphere from four CMIP6 Earth system models over the historical and ssp585 simulations.
Our analysis of contemporary (1980–2009) climatologies shows that models better reproduce observations in mid to high latitudes. The models disagree on the sign of the trend of the global DMS flux from 1980 onwards. The models agree on a positive trend of DMS over polar latitudes following sea-ice retreat dynamics.
Mariana Hill Cruz, Iris Kriest, Yonss Saranga José, Rainer Kiko, Helena Hauss, and Andreas Oschlies
Biogeosciences, 18, 2891–2916, https://doi.org/10.5194/bg-18-2891-2021, https://doi.org/10.5194/bg-18-2891-2021, 2021
Short summary
Short summary
In this study we use a regional biogeochemical model of the eastern tropical South Pacific Ocean to implicitly simulate the effect that fluctuations in populations of small pelagic fish, such as anchovy and sardine, may have on the biogeochemistry of the northern Humboldt Current System. To do so, we vary the zooplankton mortality in the model, under the assumption that these fishes eat zooplankton. We also evaluate the model for the first time against mesozooplankton observations.
Roman Bezhenar, Kyeong Ok Kim, Vladimir Maderich, Govert de With, and Kyung Tae Jung
Biogeosciences, 18, 2591–2607, https://doi.org/10.5194/bg-18-2591-2021, https://doi.org/10.5194/bg-18-2591-2021, 2021
Short summary
Short summary
A new approach to predicting the accumulation of radionuclides in fish was developed by taking into account heterogeneity of distribution of contamination in the organism and dependence of metabolic process rates on the fish mass. Predicted concentrations of radionuclides in fish agreed well with the laboratory and field measurements. The model with the defined generic parameters could be used in marine environments without local calibration, which is important for emergency decision support.
Emil De Borger, Justin Tiano, Ulrike Braeckman, Adriaan D. Rijnsdorp, and Karline Soetaert
Biogeosciences, 18, 2539–2557, https://doi.org/10.5194/bg-18-2539-2021, https://doi.org/10.5194/bg-18-2539-2021, 2021
Short summary
Short summary
Bottom trawling alters benthic mineralization: the recycling of organic material (OM) to free nutrients. To better understand how this occurs, trawling events were added to a model of seafloor OM recycling. Results show that bottom trawling reduces OM and free nutrients in sediments through direct removal thereof and of fauna which transport OM to deeper sediment layers protected from fishing. Our results support temporospatial trawl restrictions to allow key sediment functions to recover.
Britta Munkes, Ulrike Löptien, and Heiner Dietze
Biogeosciences, 18, 2347–2378, https://doi.org/10.5194/bg-18-2347-2021, https://doi.org/10.5194/bg-18-2347-2021, 2021
Short summary
Short summary
Cyanobacteria blooms can strongly aggravate eutrophication problems of water bodies. Their controls are, however, not comprehensively understood, which impedes effective management and protection plans. Here we review the current understanding of cyanobacteria blooms. Juxtaposition of respective field and laboratory studies with state-of-the-art mathematical models reveals substantial uncertainty associated with nutrient demands, grazing, and death of cyanobacteria.
Jens Terhaar, Olivier Torres, Timothée Bourgeois, and Lester Kwiatkowski
Biogeosciences, 18, 2221–2240, https://doi.org/10.5194/bg-18-2221-2021, https://doi.org/10.5194/bg-18-2221-2021, 2021
Short summary
Short summary
The uptake of carbon, emitted as a result of human activities, results in ocean acidification. We analyse 21st-century projections of acidification in the Arctic Ocean, a region of particular vulnerability, using the latest generation of Earth system models. In this new generation of models there is a large decrease in the uncertainty associated with projections of Arctic Ocean acidification, with freshening playing a greater role in driving acidification than previously simulated.
Tobias R. Vonnahme, Martial Leroy, Silke Thoms, Dick van Oevelen, H. Rodger Harvey, Svein Kristiansen, Rolf Gradinger, Ulrike Dietrich, and Christoph Völker
Biogeosciences, 18, 1719–1747, https://doi.org/10.5194/bg-18-1719-2021, https://doi.org/10.5194/bg-18-1719-2021, 2021
Short summary
Short summary
Diatoms are crucial for Arctic coastal spring blooms, and their growth is controlled by nutrients and light. At the end of the bloom, inorganic nitrogen or silicon can be limiting, but nitrogen can be regenerated by bacteria, extending the algal growth phase. Modeling these multi-nutrient dynamics and the role of bacteria is challenging yet crucial for accurate modeling. We recreated spring bloom dynamics in a cultivation experiment and developed a representative dynamic model.
Rebecca M. Wright, Corinne Le Quéré, Erik Buitenhuis, Sophie Pitois, and Mark J. Gibbons
Biogeosciences, 18, 1291–1320, https://doi.org/10.5194/bg-18-1291-2021, https://doi.org/10.5194/bg-18-1291-2021, 2021
Short summary
Short summary
Jellyfish have been included in a global ocean biogeochemical model for the first time. The global mean jellyfish biomass in the model is within the observational range. Jellyfish are found to play an important role in the plankton ecosystem, influencing community structure, spatiotemporal dynamics and biomass. The model raises questions about the sensitivity of the zooplankton community to jellyfish mortality and the interactions between macrozooplankton and jellyfish.
Valeria Di Biagio, Gianpiero Cossarini, Stefano Salon, and Cosimo Solidoro
Biogeosciences, 17, 5967–5988, https://doi.org/10.5194/bg-17-5967-2020, https://doi.org/10.5194/bg-17-5967-2020, 2020
Short summary
Short summary
Events that influence the functioning of the Earth’s ecosystems are of interest in relation to a changing climate. We propose a method to identify and characterise
wavesof extreme events affecting marine ecosystems for multi-week periods over wide areas. Our method can be applied to suitable ecosystem variables and has been used to describe different kinds of extreme event waves of phytoplankton chlorophyll in the Mediterranean Sea, by analysing the output from a high-resolution model.
Maria Paula da Silva, Lino A. Sander de Carvalho, Evlyn Novo, Daniel S. F. Jorge, and Claudio C. F. Barbosa
Biogeosciences, 17, 5355–5364, https://doi.org/10.5194/bg-17-5355-2020, https://doi.org/10.5194/bg-17-5355-2020, 2020
Short summary
Short summary
In this study, we analyze the seasonal changes in the dissolved organic matter (DOM) quality (based on its optical properties) in four Amazon floodplain lakes. DOM plays a fundamental role in surface water chemistry, controlling metal bioavailability and mobility, and nutrient cycling. The model proposed in our paper highlights the potential to study DOM quality at a wider spatial scale, which may help to better understand the persistence and fate of DOM in the ecosystem.
Zhengchen Zang, Z. George Xue, Kehui Xu, Samuel J. Bentley, Qin Chen, Eurico J. D'Sa, Le Zhang, and Yanda Ou
Biogeosciences, 17, 5043–5055, https://doi.org/10.5194/bg-17-5043-2020, https://doi.org/10.5194/bg-17-5043-2020, 2020
Taylor A. Shropshire, Steven L. Morey, Eric P. Chassignet, Alexandra Bozec, Victoria J. Coles, Michael R. Landry, Rasmus Swalethorp, Glenn Zapfe, and Michael R. Stukel
Biogeosciences, 17, 3385–3407, https://doi.org/10.5194/bg-17-3385-2020, https://doi.org/10.5194/bg-17-3385-2020, 2020
Short summary
Short summary
Zooplankton are the smallest animals in the ocean and important food for fish. Despite their importance, zooplankton have been relatively undersampled. To better understand the zooplankton community in the Gulf of Mexico (GoM), we developed a model to simulate their dynamics. We found that heterotrophic protists are important for supporting mesozooplankton, which are the primary prey of larval fish. The model developed in this study has the potential to improve fisheries management in the GoM.
Iris Kriest, Paul Kähler, Wolfgang Koeve, Karin Kvale, Volkmar Sauerland, and Andreas Oschlies
Biogeosciences, 17, 3057–3082, https://doi.org/10.5194/bg-17-3057-2020, https://doi.org/10.5194/bg-17-3057-2020, 2020
Short summary
Short summary
Constants of global biogeochemical ocean models are often tuned
by handto match observations of nutrients or oxygen. We investigate the effect of this tuning by optimising six constants of a global biogeochemical model, simulated in five different offline circulations. Optimal values for three constants adjust to distinct features of the circulation applied and can afterwards be swapped among the circulations, without losing too much of the model's fit to observed quantities.
Laura Haffert, Matthias Haeckel, Henko de Stigter, and Felix Janssen
Biogeosciences, 17, 2767–2789, https://doi.org/10.5194/bg-17-2767-2020, https://doi.org/10.5194/bg-17-2767-2020, 2020
Short summary
Short summary
Deep-sea mining for polymetallic nodules is expected to have severe environmental impacts. Through prognostic modelling, this study aims to provide a holistic assessment of the biogeochemical recovery after a disturbance event. It was found that the recovery strongly depends on the impact type; e.g. complete removal of the surface sediment reduces seafloor nutrient fluxes over centuries.
Fabian A. Gomez, Rik Wanninkhof, Leticia Barbero, Sang-Ki Lee, and Frank J. Hernandez Jr.
Biogeosciences, 17, 1685–1700, https://doi.org/10.5194/bg-17-1685-2020, https://doi.org/10.5194/bg-17-1685-2020, 2020
Short summary
Short summary
We use a numerical model to infer annual changes of surface carbon chemistry in the Gulf of Mexico (GoM). The main seasonality drivers of partial pressure of carbon dioxide and aragonite saturation state from the model are temperature and river runoff. The GoM basin is a carbon sink in winter–spring and carbon source in summer–fall, but uptake prevails near the Mississippi Delta year-round due to high biological production. Our model results show good correspondence with observational studies.
Simon J. Parker
Biogeosciences, 17, 305–315, https://doi.org/10.5194/bg-17-305-2020, https://doi.org/10.5194/bg-17-305-2020, 2020
Short summary
Short summary
Dissolved oxygen (DO) models typically assume constant ecosystem respiration over the course of a single day. Using a data-driven approach, this research examines this assumption in four streams across two (hydro-)geological types (Chalk and Greensand). Despite hydrogeological equivalence in terms of baseflow index for each hydrogeological pairing, model suitability differed within, rather than across, geology types. This corresponded with associated differences in timings of DO minima.
Fabrice Lacroix, Tatiana Ilyina, and Jens Hartmann
Biogeosciences, 17, 55–88, https://doi.org/10.5194/bg-17-55-2020, https://doi.org/10.5194/bg-17-55-2020, 2020
Short summary
Short summary
Contributions of rivers to the oceanic cycling of carbon have been poorly represented in global models until now. Here, we assess the long–term implications of preindustrial riverine loads in the ocean in a novel framework which estimates the loads through a hierarchy of weathering and land–ocean export models. We investigate their impacts for the oceanic biological production and air–sea carbon flux. Finally, we assess the potential incorporation of the framework in an Earth system model.
Patrick A. Rafter, Aaron Bagnell, Dario Marconi, and Timothy DeVries
Biogeosciences, 16, 2617–2633, https://doi.org/10.5194/bg-16-2617-2019, https://doi.org/10.5194/bg-16-2617-2019, 2019
Short summary
Short summary
The N isotopic composition of nitrate (
nitrate δ15N) is a useful tracer of ocean N cycling and many other ocean processes. Here, we use a global compilation of marine nitrate δ15N as an input, training, and validating dataset for an artificial neural network (a.k.a.,
machine learning) and examine basin-scale trends in marine nitrate δ15N from the surface to the seafloor.
Elena Terzić, Paolo Lazzari, Emanuele Organelli, Cosimo Solidoro, Stefano Salon, Fabrizio D'Ortenzio, and Pascal Conan
Biogeosciences, 16, 2527–2542, https://doi.org/10.5194/bg-16-2527-2019, https://doi.org/10.5194/bg-16-2527-2019, 2019
Short summary
Short summary
Measuring ecosystem properties in the ocean is a hard business. Recent availability of data from Biogeochemical-Argo floats can help make this task easier. Numerical models can integrate these new data in a coherent picture and can be used to investigate the functioning of ecosystem processes. Our new approach merges experimental information and model capabilities to quantitatively demonstrate the importance of light and water vertical mixing for algae dynamics in the Mediterranean Sea.
Jens Terhaar, James C. Orr, Marion Gehlen, Christian Ethé, and Laurent Bopp
Biogeosciences, 16, 2343–2367, https://doi.org/10.5194/bg-16-2343-2019, https://doi.org/10.5194/bg-16-2343-2019, 2019
Short summary
Short summary
A budget of anthropogenic carbon in the Arctic Ocean, the main driver of open-ocean acidification, was constructed for the first time using a high-resolution ocean model. The budget reveals that anthropogenic carbon enters the Arctic Ocean mainly by lateral transport; the air–sea flux plays a minor role. Coarser-resolution versions of the same model, typical of earth system models, store less anthropogenic carbon in the Arctic Ocean and thus underestimate ocean acidification in the Arctic Ocean.
Taylor S. Martin, François Primeau, and Karen L. Casciotti
Biogeosciences, 16, 347–367, https://doi.org/10.5194/bg-16-347-2019, https://doi.org/10.5194/bg-16-347-2019, 2019
Short summary
Short summary
Nitrite is a key intermediate in many nitrogen (N) cycling processes in the ocean, particularly in areas with low oxygen that are hotspots for N loss. We have created a 3-D global N cycle model with nitrite as a tracer. Stable isotopes of N are also included in the model and we are able to model the isotope fractionation associated with each N cycling process. Our model accurately represents N concentrations and isotope distributions in the ocean.
Camille Richon, Jean-Claude Dutay, Laurent Bopp, Briac Le Vu, James C. Orr, Samuel Somot, and François Dulac
Biogeosciences, 16, 135–165, https://doi.org/10.5194/bg-16-135-2019, https://doi.org/10.5194/bg-16-135-2019, 2019
Short summary
Short summary
We evaluate the effects of climate change and biogeochemical forcing evolution on the nutrient and plankton cycles of the Mediterranean Sea for the first time. We use a high-resolution coupled physical and biogeochemical model and perform 120-year transient simulations. The results indicate that changes in external nutrient fluxes and climate change may have synergistic or antagonistic effects on nutrient concentrations, depending on the region and the scenario.
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.
Prima Anugerahanti, Shovonlal Roy, and Keith Haines
Biogeosciences, 15, 6685–6711, https://doi.org/10.5194/bg-15-6685-2018, https://doi.org/10.5194/bg-15-6685-2018, 2018
Short summary
Short summary
Minor changes in the biogeochemical model equations lead to major dynamical changes. We assessed this structural sensitivity for the MEDUSA biogeochemical model on chlorophyll and nitrogen concentrations at five oceanographic stations over 10 years, using 1-D ensembles generated by combining different process equations. The ensemble performed better than the default model in most of the stations, suggesting that our approach is useful for generating a probabilistic biogeochemical ensemble model.
Jenny Hieronymus, Kari Eilola, Magnus Hieronymus, H. E. Markus Meier, Sofia Saraiva, and Bengt Karlson
Biogeosciences, 15, 5113–5129, https://doi.org/10.5194/bg-15-5113-2018, https://doi.org/10.5194/bg-15-5113-2018, 2018
Short summary
Short summary
This paper investigates how phytoplankton concentrations in the Baltic Sea co-vary with nutrient concentrations and other key variables on inter-annual timescales in a model integration over the years 1850–2008. The study area is not only affected by climate change; it has also been subjected to greatly increased nutrient loads due to extensive use of agricultural fertilizers. The results indicate the largest inter-annual coherence of phytoplankton with the limiting nutrient.
Cyril Dutheil, Olivier Aumont, Thomas Gorguès, Anne Lorrain, Sophie Bonnet, Martine Rodier, Cécile Dupouy, Takuhei Shiozaki, and Christophe Menkes
Biogeosciences, 15, 4333–4352, https://doi.org/10.5194/bg-15-4333-2018, https://doi.org/10.5194/bg-15-4333-2018, 2018
Short summary
Short summary
N2 fixation is recognized as one of the major sources of nitrogen in the ocean. Thus, N2 fixation sustains a significant part of the primary production (PP) by supplying the most common limiting nutrient for phytoplankton growth. From numerical simulations, the local maximums of Trichodesmium biomass in the Pacific are found around islands, explained by the iron fluxes from island sediments. We assessed that 15 % of the PP may be due to Trichodesmium in the low-nutrient, low-chlorophyll areas.
Akitomo Yamamoto, Ayako Abe-Ouchi, and Yasuhiro Yamanaka
Biogeosciences, 15, 4163–4180, https://doi.org/10.5194/bg-15-4163-2018, https://doi.org/10.5194/bg-15-4163-2018, 2018
Short summary
Short summary
Millennial-scale changes in oceanic CO2 uptake due to global warming are simulated by a GCM and offline biogeochemical model. Sensitivity studies show that decreases in oceanic CO2 uptake are mainly caused by a weaker biological pump and seawater warming. Enhanced CO2 uptake due to weaker equatorial upwelling cancels out reduced CO2 uptake due to weaker AMOC and AABW formation. Thus, circulation change plays only a small direct role in reduction of CO2 uptake due to global warming.
Fabian A. Gomez, Sang-Ki Lee, Yanyun Liu, Frank J. Hernandez Jr., Frank E. Muller-Karger, and John T. Lamkin
Biogeosciences, 15, 3561–3576, https://doi.org/10.5194/bg-15-3561-2018, https://doi.org/10.5194/bg-15-3561-2018, 2018
Short summary
Short summary
Seasonal patterns in nanophytoplankton and diatom biomass in the Gulf of Mexico were examined with an ocean–biogeochemical model. We found silica limitation of model diatom growth in the deep GoM and Mississippi delta. Zooplankton grazing and both transport and vertical mixing of biomass substantially influence the model phytoplankton biomass seasonality. We stress the need for integrated analyses of biologically and physically driven biomass fluxes to describe phytoplankton seasonal changes.
Martí Galí, Maurice Levasseur, Emmanuel Devred, Rafel Simó, and Marcel Babin
Biogeosciences, 15, 3497–3519, https://doi.org/10.5194/bg-15-3497-2018, https://doi.org/10.5194/bg-15-3497-2018, 2018
Short summary
Short summary
We developed a new algorithm to estimate the sea-surface concentration of dimethylsulfide (DMS) using satellite data. DMS is a gas produced by marine plankton that, once emitted to the atmosphere, plays a key climatic role by seeding cloud formation. We used the algorithm to produce global DMS maps and also regional DMS time series. The latter suggest that DMS can vary largely from one year to another, which should be taken into account in atmospheric studies.
Cited articles
Baklouti, M., Faure, V., Pawlowski, L., and Sciandra, A.: Investigation and
sensitivity analysis of a mechanistic phytoplankton model implemented in a
new modular numerical tool (Eco3M) dedicated to biogeochemical modelling,
Prog. Oceanogr., 71, 34–58, https://doi.org/10.1016/j.pocean.2006.05.003,
2006. a
Bates, N. R. and Hansell, D. A.: Temporal variability of excess nitrate in
the
subtropical mode water of the North Atlantic Ocean, Marine Chem.,
84, 225–241, https://doi.org/10.1016/j.marchem.2003.08.003,
2004. a
Behrenfeld, M. J., O'Malley, R. T., Siegel, D. A., McClain, C. R.,
Sarmiento,
J. L., Feldman, G. C., Milligan, A. J., Falkowski, P. G., Letelier, R. M.,
and Boss, E. S.: Climate-driven trends in contemporary ocean productivity,
Nature, 444, 752–755, https://doi.org/10.1038/nature05317,
2006. a
Benavides, M., Agawin, N., Aristegui, J., Penne, J., and Stal, L.: Dissolved
organic nitrogen and carbon release by a marine unicellular diazotrophic
cyanobacterium, Aquat. Microb. Ecol., 69, 69–80, 2013. a
Berthelot, H., Bonnet, S., Camps, M., Grosso, O., and Moutin, T.: Assessment
of
the dinitrogen released as ammonium and dissolved organic nitrogen by
unicellular and filamentous marine diazotrophic cyanobacteria grown in
culture, Front. Mar. Sci., 2, 80, https://doi.org/10.3389/fmars.2015.00080,
2015. a
Bonnet, S., Caffin, M., Berthelot, H., and Moutin, T.: Hot spot of N2
fixation in the western tropical South Pacific pleads for a spatial
decoupling between N2 fixation and denitrification, P.
Natl. Acad. Sci., 114, E2800–E2801,
https://doi.org/10.1073/pnas.1619514114,
2017. a, b, c, d
Bratbak, G.: Bacterial Biovolume and Biomass Estimations, Appl.
Environ. Microbiol., 49, 1488–1493,
1985. a
Bronk, D. A. and Ward, B. B.: Magnitude of dissolved organic nitrogen release
relative to gross nitrogen uptake in marine systems, Limnol.
Oceanogr., 45, 1879–1883, https://doi.org/10.4319/lo.2000.45.8.1879,
2000. a
Caffin, M., Moutin, T., Foster, R. A., Bouruet-Aubertot, P., Doglioli, A. M.,
Berthelot, H., Guieu, C., Grosso, O., Helias-Nunige, S., Leblond, N.,
Gimenez, A., Petrenko, A. A., de Verneil, A., and Bonnet, S.: N2 fixation
as a dominant new N source in the western tropical South Pacific Ocean
(OUTPACE cruise), Biogeosciences, 15, 2565–2585,
https://doi.org/10.5194/bg-15-2565-2018, 2018. a, b
Capone, D. G., Zehr, J. P., Paerl, H. W., Bergman, B., and Carpenter, E. J.:
Trichodesmium, a globally significant marine cyanobacterium, Science, 276,
1221–1229,
1997. a
Capone, D. G., Burns, J. A., Montoya, J. P., Subramaniam, A., Mahaffey, C.,
Gunderson, T., Michaels, A. F., and Carpenter, E. J.: Nitrogen fixation by Trichodesmium spp.: An important source
of new nitrogen to the tropical and subtropical North Atlantic Ocean,
Global Biogeochem. Cy., 19, GB2024, https://doi.org/10.1029/2004GB002331,
2005. a
Cermeño, P., Dutkiewicz, S., Harris, R. P., Follows, M., Schofield, O., and
Falkowski, P. G.: The role of nutricline depth in regulating the ocean carbon
cycle, P. Natl. Acad. Sci., 105,
20344–20349, https://doi.org/10.1073/pnas.0811302106,
2008. a
Claustre, H., Sciandra, A., and Vaulot, D.: Introduction to the special
section bio-optical and biogeochemical conditions in the South East Pacific
in late 2004: the BIOSOPE program, Biogeosciences, 5, 679–691,
https://doi.org/10.5194/bg-5-679-2008, 2008. a
Coles, V. J. and Hood, R. R.: Modeling the impact of iron and phosphorus
limitations on nitrogen fixation in the Atlantic Ocean, Biogeosciences, 4,
455–479, https://doi.org/10.5194/bg-4-455-2007, 2007. a, b
Cotner, J. B., Hall, E. K., Scott, T., and Heldal, M.: Freshwater Bacteria
are Stoichiometrically Flexible with a Nutrient Composition Similar
to Seston, Front. Microbiol., 1, https://doi.org/10.3389/fmicb.2010.00132,
2010. a
de Baar, H. J. W.: Von Liebig's law of the minimum and plankton ecology
(1899–1991), Prog. Oceanogr., 33, 347–386,
https://doi.org/10.1016/0079-6611(94)90022-1,
1994. a
de Verneil, A., Rousselet, L., Doglioli, A. M., Petrenko, A. A., Maes, C.,
Bouruet-Aubertot, P., and Moutin, T.: OUTPACE long duration stations:
physical variability, context of biogeochemical sampling, and evaluation of
sampling strategy, Biogeosciences, 15, 2125–2147,
https://doi.org/10.5194/bg-15-2125-2018, 2018. a
Dutheil, C., Aumont, O., Gorguès, T., Lorrain, A., Bonnet, S., Rodier, M.,
Dupouy, C., Shiozaki, T., and Menkes, C.: Modelling N2 fixation related to
Trichodesmium sp.: driving processes and impacts on primary
production in the tropical Pacific Ocean, Biogeosciences, 15, 4333–4352,
https://doi.org/10.5194/bg-15-4333-2018, 2018. a
Dutkiewicz, S., Ward, B. A., Scott, J. R., and Follows, M. J.: Understanding
predicted shifts in diazotroph biogeography using resource competition
theory, available at:
http://dspace.mit.edu/handle/1721.1/92505 (last access: 4 October 2018), 2014. a
Falkowski, P. G.: Evolution of the nitrogen cycle and its influence on the
biological sequestration of CO2 in the ocean, Nature, 387, 272–275,
https://doi.org/10.1038/387272a0,
1997. a, b
Falkowski, P. G., Barber, R. T., and Smetacek, V.: Biogeochemical controls
and
feedbacks on ocean primary production, Science, 281, 200–206,
1998. a
Fennel, K., Spitz, Y. H., Letelier, R. M., Abbott, M. R., and Karl, D. M.: A
deterministic model for N2 fixation at stn. ALOHA in the
subtropical North Pacific Ocean, Deep Sea Res. Pt. II, 49, 149–174,
2002. a
Fumenia, A., Moutin, T., Bonnet, S., Benavides, M., Petrenko, A., Helias
Nunige, S., and Maes, C.: Excess nitrogen as a marker of intense dinitrogen
fixation in the Western Tropical South Pacific Ocean: impact on the
thermocline waters of the South Pacific, Biogeosciences Discuss.,
https://doi.org/10.5194/bg-2017-557, in review, 2018. a, b, c
Gaspar, P.: Modeling the Seasonal Cycle of the Upper Ocean, J.
Phys. Oceanogr., 18, 161–180,
https://doi.org/10.1175/1520-0485(1988)018<0161:MTSCOT>2.0.CO;2,
1988. a
Gaspar, P., Grégoris, Y., and Lefevre, J.-M.: A simple eddy kinetic energy
model for simulations of the oceanic vertical mixing: Tests at station
Papa and long-term upper ocean study site, J. Geophys. Res.,
95, 16179, https://doi.org/10.1029/JC095iC09p16179,
1990. a
Gimenez, A., Baklouti, M., Bonnet, S., and Moutin, T.: Biogeochemical fluxes
and fate of diazotroph-derived nitrogen in the food web after a phosphate
enrichment: modeling of the VAHINE mesocosms experiment, Biogeosciences, 13,
5103–5120, https://doi.org/10.5194/bg-13-5103-2016, 2016. a, b, c, d, e, f, g, h
Goldman, J. C. and Dennett, M. R.: Growth of marine bacteria in batch and
continuous culture under carbon and nitrogen limitation, Limnol.
Oceanogr., 45, 789–800, https://doi.org/10.4319/lo.2000.45.4.0789,
2000. a
Grimaud, G. M., Dron, A., Rabouille, S., Sciandra, A., and Bernard, O.: Modelling light-dark regime influence on the carbon-nitrogen
metabolism in a unicellular diazotrophic cyanobacterium, in: CAB,
available at: http://hal.upmc.fr/hal-00854479 (last access: 8 October 2018), 2013. a
Gruber, N.: The dynamics of the marine nitrogen cycle and its influence on
atmospheric CO2 variations, in: The ocean carbon cycle and
climate, 97–148, Springer, 2004. a
Gruber, N. and Sarmiento, J. L.: Global patterns of marine nitrogen fixation
and denitrification, Global Biogeochem. Cy., 11, 235–266,
https://doi.org/10.1029/97GB00077,
1997. a, b
Guieu, C., Bonnet, S., Petrenko, A., Menkes, C., Chavagnac, V., Desboeufs,
K.,
Maes, C., and Moutin, T.: Iron from a submarine source impacts the productive
layer of the Western Tropical South Pacific (WTSP), Scientific
Reports, 8, 9075, https://doi.org/10.1038/s41598-018-27407-z,
2018. a, b
Hansell, D. A., Bates, N. R., and Olson, D. B.: Excess nitrate and nitrogen
fixation in the North Atlantic Ocean, Marine Chem., 84, 243–265,
https://doi.org/10.1016/j.marchem.2003.08.004,
2004. a
Holl, C. M. and Montoya, J. P.: Diazotrophic growth of the marine
yanobacterium
Trichodesmium Ims101 in continuous culture: effects of growth rate on
N2-fixation rate, biomass, and C:N:P stoichiometry,
J. Phycol., 44, 929–937, https://doi.org/10.1111/j.1529-8817.2008.00534.x,
2008. a
Hutchins, D. A., Fu, F.-X., Zhang, Y., Warner, M. E., Feng, Y., Portune, K.,
Bernhardt, P. W., and Mulholland, M. R.: CO2 control of Trichodesmium
N2 fixation, photosynthesis, growth rates, and elemental ratios:
Implications for past, present, and future ocean biogeochemistry, Limnol. Oceanogr., 52, 1293–1304, https://doi.org/10.4319/lo.2007.52.4.1293,
2007. a
Karl, D. and Letelier, R.: Nitrogen fixation-enhanced carbon sequestration in
low nitrate, low chlorophyll seascapes, Mar. Ecol. Prog. Ser., 364,
257–268, https://doi.org/10.3354/meps07547,
2008. a
Karl, D., Letelier, R., Tupas, L., Dore, J., Christian, J., and Hebel, D.:
The
role of nitrogen fixation in biogeochemical cycling in the subtropical
North Pacific Ocean, Nature, 388, 533–538, https://doi.org/10.1038/41474,
1997. a, b
Karl, D., Michaels, A., Bergman, B., Capone, D., Carpenter, E., Letelier, R.,
Lipschultz, F., Paerl, H., Sigman, D., and Stal, L.: Dinitrogen fixation in
the world's oceans, Biogeochemistry, 57-58, 47–98,
https://doi.org/10.1023/A:1015798105851,
2002. a
Landolfi, A., Oschlies, A., and Sanders, R.: Organic nutrients and excess
nitrogen in the North Atlantic subtropical gyre, Biogeosciences, 5,
1199–1213, https://doi.org/10.5194/bg-5-1199-2008, 2008. a
Law, C. S., Woodward, E. M. S., Ellwood, M. J., Marriner, A., Bury, S. J.,
and
Safi, K. A.: Response of surface nutrient inventories and nitrogen fixation
to a tropical cyclone in the southwest Pacific, Limnol. Oceanogr.,
56, 1372–1385, https://doi.org/10.4319/lo.2011.56.4.1372,
2011. a, b
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. Volume 1,
Temperature, Tech. rep., NOAA Atlas NESDIS 73, https://doi.org/10.7289/V55X26VD,
2013. a
Luo, Y.-W., Doney, S. C., Anderson, L. A., Benavides, M., Berman-Frank, I.,
Bode, A., Bonnet, S., Boström, K. H., Böttjer, D., Capone, D. G.,
Carpenter, E. J., Chen, Y. L., Church, M. J., Dore, J. E., Falcón, L. I.,
Fernández, A., Foster, R. A., Furuya, K., Gómez, F., Gundersen, K.,
Hynes, A. M., Karl, D. M., Kitajima, S., Langlois, R. J., LaRoche, J.,
Letelier, R. M., Marañón, E., McGillicuddy Jr., D. J., Moisander, P. H.,
Moore, C. M., Mouriño-Carballido, B., Mulholland, M. R., Needoba, J. A.,
Orcutt, K. M., Poulton, A. J., Rahav, E., Raimbault, P., Rees, A. P.,
Riemann, L., Shiozaki, T., Subramaniam, A., Tyrrell, T., Turk-Kubo, K. A.,
Varela, M., Villareal, T. A., Webb, E. A., White, A. E., Wu, J., and Zehr, J.
P.: Database of diazotrophs in global ocean: abundance, biomass and nitrogen
fixation rates, Earth Syst. Sci. Data, 4, 47–73,
https://doi.org/10.5194/essd-4-47-2012, 2012. a
Martiny, A. C., Pham, C. T. A., Primeau, F. W., Vrugt, J. A., Moore, J. K.,
Levin, S. A., and Lomas, M. W.: Strong latitudinal patterns in the elemental
ratios of marine plankton and organic matter, Nature Geosci., 6, 279–283,
https://doi.org/10.1038/ngeo1757,
2013. a
Martínez, L., Silver, M. W., King, J. M., and Alldredge, A. L.: Nitrogen
Fixation by Floating Diatom Mats: A Source of New Nitrogen to
Oligotrophic Ocean Waters, Science, 221, 152–154,
https://doi.org/10.1126/science.221.4606.152,
1983. a
Mauriac, R., Moutin, T., and Baklouti, M.: Accumulation of DOC in Low
Phosphate Low Chlorophyll (LPLC) area: is it related to higher production
under high N:P ratio?, Biogeosciences, 8, 933–950,
https://doi.org/10.5194/bg-8-933-2011, 2011. a
Meyers, G.: On the Annual Rossby Wave in the Tropical North
Pacific
Ocean, J. Phys. Oceanogr., 9, 663–674,
https://doi.org/10.1175/1520-0485(1979)009<0663:OTARWI>2.0.CO;2,
1979. a
Mills, M. M., Ridame, C., Davey, M., La Roche, J., and Geider, R. J.: Iron
and
phosphorus co-limit nitrogen fixation in the eastern tropical North
Atlantic, Nature, 429, 292–294,
2004. a
Moisander, P. H., Zhang, R., Boyle, E. A., Hewson, I., Montoya, J. P., and
Zehr, J. P.: Analogous nutrient limitations in unicellular diazotrophs and
Prochlorococcus in the South Pacific Ocean, The ISME Journal, 6,
733–744,
2012. a
Monteiro, F. M., Dutkiewicz, S., and Follows, M. J.: Biogeographical controls
on the marine nitrogen fixers: controls on marine nitrogen fixers, Global
Biogeochem. Cy., 25, https://doi.org/10.1029/2010GB003902,
2011. a, b
Moore, J. K., Doney, S. C., Glover, D. M., and Fung, I. Y.: Iron cycling and
nutrient-limitation patterns in surface waters of the World Ocean, Deep
Sea Res. Pt. II, 49, 463–507,
https://doi.org/10.1016/S0967-0645(01)00109-6,
2002. a
Moore, J. K., Doney, S. C., and Lindsay, K.: Upper ocean ecosystem dynamics
and
iron cycling in a global three-dimensional model: global
ecosystem-biogeochemical model, Global Biogeochem. Cy., 18,
https://doi.org/10.1029/2004GB002220,
2004. a
Moutin, T., Karl, D. M., Duhamel, S., Rimmelin, P., Raimbault, P., Van Mooy,
B. A. S., and Claustre, H.: Phosphate availability and the ultimate control
of new nitrogen input by nitrogen fixation in the tropical Pacific Ocean,
Biogeosciences, 5, 95–109, https://doi.org/10.5194/bg-5-95-2008, 2008. a, b, c, d
Moutin, T., Doglioli, A. M., de Verneil, A., and Bonnet, S.: Preface: The
Oligotrophy to the UlTra-oligotrophy PACific Experiment (OUTPACE cruise, 18
February to 3 April 2015), Biogeosciences, 14, 3207–3220,
https://doi.org/10.5194/bg-14-3207-2017, 2017. a, b
Moutin, T., Wagener, T., Caffin, M., Fumenia, A., Gimenez, A., Baklouti, M.,
Bouruet-Aubertot, P., Pujo-Pay, M., Leblanc, K., Lefevre, D., Helias Nunige,
S., Leblond, N., Grosso, O., and de Verneil, A.: Nutrient availability and
the ultimate control of the biological carbon pump in the western tropical
South Pacific Ocean, Biogeosciences, 15, 2961–2989,
https://doi.org/10.5194/bg-15-2961-2018, 2018. a, b, c, d, e, f, g
Mulholland, M., Bronk, D., and Capone, D.: Dinitrogen fixation and release of
ammonium and dissolved organic nitrogen by Trichodesmium IMS101, Aquat.
Microbial. Ecol., 37, 85–94, https://doi.org/10.3354/ame037085,
2004. a
Mulholland, M. R. and Bernhardt, P. W.: The effect of growth rate, phosphorus
concentration, and temperature on N2 fixation, carbon
fixation, and nitrogen release in continuous cultures of Trichodesmium
IMS101, Limnol. Oceanogr., 50, 839–849,
2005. a
Mulholland, M. R., Bernhardt, P. W., Heil, C. A., Bronk, D. A., and O'Neil,
J. M.: Nitrogen fixation and release of fixed nitrogen by Trichodesmium
spp. in the Gulf of Mexico, Limnol. Oceanogr., 51, 1762–1776,
2006. a
Olsen, A., Key, R. M., van Heuven, S., Lauvset, S. K., Velo, A., Lin, X.,
Schirnick, C., Kozyr, A., Tanhua, T., Hoppema, M., Jutterström, S.,
Steinfeldt, R., Jeansson, E., Ishii, M., Pérez, F. F., and Suzuki, T.: The
Global Ocean Data Analysis Project version 2 (GLODAPv2) – an internally
consistent data product for the world ocean, Earth Syst. Sci. Data, 8,
297–323, https://doi.org/10.5194/essd-8-297-2016, 2016. a
Paerl, H. W., Crocker, K. M., and Prufert, L. E.: Limitation of
N2 fixation in coastal marine waters: Relative importance
of molybdenum, iron, phosphorus, and organic matter availability1, Limnol. Oceanogr., 32, 525–536, https://doi.org/10.4319/lo.1987.32.3.0525,
1987. a
Perry, M. J.: Alkaline phosphatase activity in subtropical Central North
Pacific waters using a sensitive fluorometric method, Mar. Biol., 15,
113–119, https://doi.org/10.1007/BF00353639,
1972. a, b
Perry, M. J.: Phosphate utilization by an oceanic diatom in
phosphorus-limited
chemostat culture and in the oligotrophic waters of the central North
Pacific1, Limnol. Oceanogr., 21, 88–107,
https://doi.org/10.4319/lo.1976.21.1.0088,
1976. a, b
Polovina, J. J., Howell, E. A., and Abecassis, M.: Ocean's least productive
waters are expanding, Geophys. Res. Lett., 35, L03618,
https://doi.org/10.1029/2007GL031745,
2008. a
Rabouille, S., Staal, M., Stal, L. J., and Soetaert, K.: Modeling the
Dynamic
Regulation of Nitrogen Fixation in the Cyanobacterium Trichodesmium
sp., Appl. Environ. Microbiol., 72, 3217–3227,
https://doi.org/10.1128/AEM.72.5.3217-3227.2006,
2006. a, b, c, d
Radenac, M.-H. and Rodier, M.: Nitrate and chlorophyll distributions in
relation to thermohaline and current structures in the western tropical
Pacific during 1985–1989, Deep Sea Res. Pt. II, 43, 725–752, https://doi.org/10.1016/0967-0645(96)00025-2,
1996. a
Rueter, J. G., Ohki, K., and Fujita, Y.: The effect of iron nutrition on
photosynthesis and nitrogen fixation in cultures of Trichodesmium
(Cyanophyceae), J. Phycol., 26, 30–35,
https://doi.org/10.1111/j.0022-3646.1990.00030.x,
1990. a
Sañudo-Wilhelmy, S. A., Kustka, A. B., Gobler, C. J., Hutchins, D. A.,
Yang,
M., Lwiza, K., Burns, J., Capone, D. G., Raven, J. A., and Carpenter, E. J.:
Phosphorus limitation of nitrogen fixation by Trichodesmium in the
central Atlantic Ocean, Nature, 411, 66–69, https://doi.org/10.1038/35075041,
2001. a
Shamarock, W., Kemp, J. B., Dudhia, J., Gill, D., Barker, D., Duda, M., and
Powers, J.: A Description of the Advanced Research WRF Version 3:
NCAR Technical Note TN–475+ STR, Tech. rep., National Center for
Atmospheric Research Boulder, Colorado, USA, 2008. a
Stenegren, M., Caputo, A., Berg, C., Bonnet, S., and Foster, R. A.:
Distribution and drivers of symbiotic and free-living diazotrophic
cyanobacteria in the western tropical South Pacific, Biogeosciences, 15,
1559–1578, https://doi.org/10.5194/bg-15-1559-2018, 2018. a
Van Den Broeck, N., Moutin, T., Rodier, M., and Le Bouteiller, A.: Seasonal
variations of phosphate availability in the SW Pacific Ocean near New
Caledonia, Mar. Ecol. Prog. Ser., 268, 1–12,
2004. a
Van Wambeke, F., Gimenez, A., Duhamel, S., Dupouy, C., Lefevre, D., Pujo-Pay,
M., and Moutin, T.: Dynamics and controls of heterotrophic prokaryotic
production in the western tropical South Pacific Ocean: links with
diazotrophic and photosynthetic activity, Biogeosciences, 15, 2669–2689,
https://doi.org/10.5194/bg-15-2669-2018, 2018. a
Vidal, M., Duarte, C., Agustí, S., Gasol, J., and Vaqué, D.: Alkaline
phosphatase activities in the central Atlantic Ocean indicate large areas
with phosphorus deficiency, Mar. Ecol. Prog. Ser., 262, 43–53,
https://doi.org/10.3354/meps262043,
2003. a, b
Vrede, K., Heldal, M., Norland, S., and Bratbak, G.: Elemental Composition
(C, N, P) and Cell Volume of Exponentially Growing and
Nutrient-Limited Bacterioplankton, Appl. Environ.
Microbiol., 68, 2965–2971, https://doi.org/10.1128/AEM.68.6.2965-2971.2002,
2002.
a
Wu, J., Sunda, W., Boyle, E. A., and Karl, D. M.: Phosphate depletion in the
western North Atlantic Ocean, Science, 289, 759–762, 2000. a
Zamora, L. M., Landolfi, A., Oschlies, A., Hansell, D. A., Dietze, H., and
Dentener, F.: Atmospheric deposition of nutrients and excess N formation in
the North Atlantic, Biogeosciences, 7, 777–793,
https://doi.org/10.5194/bg-7-777-2010, 2010. a, b, c
Zehr, J. P. and Kudela, R. M.: Nitrogen Cycle of the Open Ocean: From
Genes to Ecosystems, Annu. Rev. Mar. Sci., 3, 197–225,
https://doi.org/10.1146/annurev-marine-120709-142819,
2011. a
Zehr, J. P. and McReynolds, L. A.: Use of degenerate oligonucleotides for
amplification of the nifH gene from the marine cyanobacterium
Trichodesmium thiebautii, Appl. Environ. Microbiol., 55,
2522–2526,
1989. a
Zehr, J. P. and Turner, P. J.: Nitrogen fixation: Nitrogenase genes and
gene
expression, in: Methods in Microbiology, vol. 30 of Marine
Microbiology, 271–286, Academic Press,
https://doi.org/10.1016/S0580-9517(01)30049-1,
2001. a
Zhang, R.-H., Busalacchi, A. J., and Xue, Y.: Decadal change in the
relationship between the oceanic entrainment temperature and thermocline
depth in the far western tropical Pacific, Geophys. Res. Lett.,
34, L23612, https://doi.org/10.1029/2007GL032119,
2007. a
Zimmerman, A. E., Allison, S. D., and Martiny, A. C.: Phylogenetic
constraints
on elemental stoichiometry and resource allocation in heterotrophic marine
bacteria, Environ. Microbiol., 16, 1398–1410,
https://doi.org/10.1111/1462-2920.12329,
2014. a
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, Tech. rep.,
NOAA Atlas NESDIS 74, https://doi.org/10.7289/V5251G4D, 2013. a
Short summary
During the OUTPACE cruise conducted in the oligotrophic to ultra-oligotrophic region of the western tropical South Pacific, two contrasted regions were sampled in terms of N2 fixation rates, primary production rates and nutrient availability. The aim of this work was to investigate the role of N2 fixation in the differences observed between the two contrasted areas by comparing two simulations only differing by the presence or not of N2 fixers using a 1-D biogeochemical–physical coupled model.
During the OUTPACE cruise conducted in the oligotrophic to ultra-oligotrophic region of the...
Altmetrics
Final-revised paper
Preprint