Articles | Volume 15, issue 9
https://doi.org/10.5194/bg-15-2669-2018
© 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-15-2669-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
04 May 2018
Research article |
| 04 May 2018
| 04 May 2018
Dynamics and controls of heterotrophic prokaryotic production in the western tropical South Pacific Ocean: links with diazotrophic and photosynthetic activity
France Van Wambeke
CORRESPONDING AUTHOR
Aix-Marseille Université, CNRS, Université de Toulon, IRD,
Mediterranean Institute of Oceanography (MIO) UM 110, 13288,
Marseille, France
Audrey Gimenez
Aix-Marseille Université, CNRS, Université de Toulon, IRD,
Mediterranean Institute of Oceanography (MIO) UM 110, 13288,
Marseille, France
Solange Duhamel
Lamont-Doherty Earth Observatory, Division of
Biology and Paleo Environment, Columbia University, P.O. Box
1000, 61 Route 9W, Palisades, New York 10964, USA
Cécile Dupouy
Aix-Marseille Université, CNRS, Université de Toulon, IRD,
Mediterranean Institute of Oceanography (MIO) UM 110, 13288,
Marseille, France
Aix-Marseille
Université, CNRS, Université de Toulon, IRD, Mediterranean Institute
of Oceanography (MIO) UM 110, 98848, Nouméa, New Caledonia
Dominique Lefevre
Aix-Marseille Université, CNRS, Université de Toulon, IRD,
Mediterranean Institute of Oceanography (MIO) UM 110, 13288,
Marseille, France
Mireille Pujo-Pay
CNRS, Sorbonne Université, Laboratoire d'Océanographie Microbienne (LOMIC),
UMR 7621, Observatoire
Océanologique, 66650, Banyuls-sur-mer,
France
Thierry Moutin
Aix-Marseille Université, CNRS, Université de Toulon, IRD,
Mediterranean Institute of Oceanography (MIO) UM 110, 13288,
Marseille, France
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Short summary
Short summary
We show that in the Mediterranean Sea spatial variability in N2 fixation is related to the diazotrophic community composition reflecting different nutrient requirements among species. Nutrient supply by Saharan dust is of great importance to diazotrophs, as shown by the strong stimulation of N2 fixation after a simulated dust event under present and future climate conditions; the magnitude of stimulation depends on the degree of limitation related to the diazotrophic community composition.
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Short summary
Short summary
We compared carbon remineralization rates (MRs) in the western and central Mediterranean Sea in late spring during the PEACETIME cruise, as assessed using the barium tracer. We reported higher and deeper (up to 1000 m depth) MRs in the western basin, potentially sustained by an additional particle export event driven by deep convection. The central basin is the site of a mosaic of blooming and non-blooming water masses and showed lower MRs that were restricted to the upper mesopelagic layer.
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Biogeosciences, 18, 5871–5889, https://doi.org/10.5194/bg-18-5871-2021, https://doi.org/10.5194/bg-18-5871-2021, 2021
Short summary
Short summary
We report on phosphorus dynamics in the surface layer of the Mediterranean Sea. Highly sensitive phosphate measurements revealed vertical gradients above the phosphacline. The relative contribution of diapycnal fluxes to total external supply of phosphate to the mixed layer decreased towards the east, where atmospheric deposition dominated. Taken together, external sources of phosphate contributed little to total supply, which was mainly sustained by enzymatic hydrolysis of organic phosphorus.
France Van Wambeke, Vincent Taillandier, Karine Desboeufs, Elvira Pulido-Villena, Julie Dinasquet, Anja Engel, Emilio Marañón, Céline Ridame, and Cécile Guieu
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Frédéric Gazeau, France Van Wambeke, Emilio Marañón, Maria Pérez-Lorenzo, Samir Alliouane, Christian Stolpe, Thierry Blasco, Nathalie Leblond, Birthe Zäncker, Anja Engel, Barbara Marie, Julie Dinasquet, and Cécile Guieu
Biogeosciences, 18, 5423–5446, https://doi.org/10.5194/bg-18-5423-2021, https://doi.org/10.5194/bg-18-5423-2021, 2021
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Our study shows that the impact of dust deposition on primary production depends on the initial composition and metabolic state of the tested community and is constrained by the amount of nutrients added, to sustain both the fast response of heterotrophic prokaryotes and the delayed one of phytoplankton. Under future environmental conditions, heterotrophic metabolism will be more impacted than primary production, therefore reducing the capacity of surface waters to sequester anthropogenic CO2.
Frédéric Gazeau, Céline Ridame, France Van Wambeke, Samir Alliouane, Christian Stolpe, Jean-Olivier Irisson, Sophie Marro, Jean-Michel Grisoni, Guillaume De Liège, Sandra Nunige, Kahina Djaoudi, Elvira Pulido-Villena, Julie Dinasquet, Ingrid Obernosterer, Philippe Catala, and Cécile Guieu
Biogeosciences, 18, 5011–5034, https://doi.org/10.5194/bg-18-5011-2021, https://doi.org/10.5194/bg-18-5011-2021, 2021
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This paper shows that the impacts of Saharan dust deposition in different Mediterranean basins are as strong as those observed in coastal waters but differed substantially between the three tested stations, differences attributed to variable initial metabolic states. A stronger impact of warming and acidification on mineralization suggests a decreased capacity of Mediterranean surface communities to sequester CO2 following the deposition of atmospheric particles in the coming decades.
Evelyn Freney, Karine Sellegri, Alessia Nicosia, Leah R. Williams, Matteo Rinaldi, Jonathan T. Trueblood, André S. H. Prévôt, Melilotus Thyssen, Gérald Grégori, Nils Haëntjens, Julie Dinasquet, Ingrid Obernosterer, France Van Wambeke, Anja Engel, Birthe Zäncker, Karine Desboeufs, Eija Asmi, Hilkka Timonen, and Cécile Guieu
Atmos. Chem. Phys., 21, 10625–10641, https://doi.org/10.5194/acp-21-10625-2021, https://doi.org/10.5194/acp-21-10625-2021, 2021
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In this work, we present observations of the organic aerosol content in primary sea spray aerosols (SSAs) continuously generated along a 5-week cruise in the Mediterranean. This information is combined with seawater biogeochemical properties also measured continuously along the ship track to develop a number of parametrizations that can be used in models to determine SSA organic content in oligotrophic waters that represent 60 % of the oceans from commonly measured seawater variables.
France Van Wambeke, Elvira Pulido, Philippe Catala, Julie Dinasquet, Kahina Djaoudi, Anja Engel, Marc Garel, Sophie Guasco, Barbara Marie, Sandra Nunige, Vincent Taillandier, Birthe Zäncker, and Christian Tamburini
Biogeosciences, 18, 2301–2323, https://doi.org/10.5194/bg-18-2301-2021, https://doi.org/10.5194/bg-18-2301-2021, 2021
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Michaelis–Menten kinetics were determined for alkaline phosphatase, aminopeptidase and β-glucosidase in the Mediterranean Sea. Although the ectoenzymatic-hydrolysis contribution to heterotrophic prokaryotic needs was high in terms of N, it was low in terms of C. This study points out the biases in interpretation of the relative differences in activities among the three tested enzymes in regard to the choice of added concentrations of fluorogenic substrates.
Stéphanie H. M. Jacquet, Dominique Lefèvre, Christian Tamburini, Marc Garel, Frédéric A. C. Le Moigne, Nagib Bhairy, and Sophie Guasco
Biogeosciences, 18, 2205–2212, https://doi.org/10.5194/bg-18-2205-2021, https://doi.org/10.5194/bg-18-2205-2021, 2021
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We present new data concerning the relation between biogenic barium (Baxs, a tracer of carbon remineralization at mesopelagic depths), O2 consumption and prokaryotic heterotrophic production (PHP) in the Mediterranean Sea. The purpose of this paper is to improve our understanding of the relation between Baxs, PHP and O2 and to test the validity of the Dehairs transfer function in the Mediterranean Sea. This relation has never been tested in the Mediterranean Sea.
Emilio Marañón, France Van Wambeke, Julia Uitz, Emmanuel S. Boss, Céline Dimier, Julie Dinasquet, Anja Engel, Nils Haëntjens, María Pérez-Lorenzo, Vincent Taillandier, and Birthe Zäncker
Biogeosciences, 18, 1749–1767, https://doi.org/10.5194/bg-18-1749-2021, https://doi.org/10.5194/bg-18-1749-2021, 2021
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The concentration of chlorophyll is commonly used as an indicator of the abundance of photosynthetic plankton (phytoplankton) in lakes and oceans. Our study investigates why a deep chlorophyll maximum, located near the bottom of the upper, illuminated layer develops in the Mediterranean Sea. We find that the acclimation of cells to low light is the main mechanism involved and that this deep maximum represents also a maximum in the biomass and carbon fixation activity of phytoplankton.
Caroline Ulses, Claude Estournel, Marine Fourrier, Laurent Coppola, Fayçal Kessouri, Dominique Lefèvre, and Patrick Marsaleix
Biogeosciences, 18, 937–960, https://doi.org/10.5194/bg-18-937-2021, https://doi.org/10.5194/bg-18-937-2021, 2021
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We analyse the seasonal cycle of O2 and estimate an annual O2 budget in the north-western Mediterranean deep-convection region, using a numerical model. We show that this region acts as a large sink of atmospheric O2 and as a major source of O2 for the western Mediterranean Sea. The decrease in the deep convection intensity predicted in recent projections may have important consequences on the overall uptake of O2 in the Mediterranean Sea and on the O2 exchanges with the Atlantic Ocean.
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
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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.
Kahina Djaoudi, France Van Wambeke, Aude Barani, Nagib Bhairy, Servanne Chevaillier, Karine Desboeufs, Sandra Nunige, Mohamed Labiadh, Thierry Henry des Tureaux, Dominique Lefèvre, Amel Nouara, Christos Panagiotopoulos, Marc Tedetti, and Elvira Pulido-Villena
Biogeosciences, 17, 6271–6285, https://doi.org/10.5194/bg-17-6271-2020, https://doi.org/10.5194/bg-17-6271-2020, 2020
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
Christos Panagiotopoulos, Mireille Pujo-Pay, Mar Benavides, France Van Wambeke, and Richard Sempéré
Biogeosciences, 16, 105–116, https://doi.org/10.5194/bg-16-105-2019, https://doi.org/10.5194/bg-16-105-2019, 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
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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.
Audrey Gimenez, Melika Baklouti, Thibaut Wagener, and Thierry Moutin
Biogeosciences, 15, 6573–6589, https://doi.org/10.5194/bg-15-6573-2018, https://doi.org/10.5194/bg-15-6573-2018, 2018
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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.
Cécile Dupouy, Robert Frouin, Marc Tedetti, Morgane Maillard, Martine Rodier, Fabien Lombard, Lionel Guidi, Marc Picheral, Jacques Neveux, Solange Duhamel, Bruno Charrière, and Richard Sempéré
Biogeosciences, 15, 5249–5269, https://doi.org/10.5194/bg-15-5249-2018, https://doi.org/10.5194/bg-15-5249-2018, 2018
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The marine diazotrophic Cyanobacterium Trichodesmium from the Underwater Vision Profiler 5 is concentrated in the first 50 m in the western tropical Pacific Ocean (18–22° S, 160° E–160° W). Its contribution to Tchl a and zeaxanthin is 60 % in the Melanesian archipelago and 30 % in the Fijian archipelago. Its impact on UV–VIS radiance is a peculiar signal in the green and yellow and possibly associated with backscattering or phycoerythrin fluorescence from Trichodesmium.
Guillaume Rousset, Florian De Boissieu, Christophe E. Menkes, Jérôme Lefèvre, Robert Frouin, Martine Rodier, Vincent Ridoux, Sophie Laran, Sophie Bonnet, and Cécile Dupouy
Biogeosciences, 15, 5203–5219, https://doi.org/10.5194/bg-15-5203-2018, https://doi.org/10.5194/bg-15-5203-2018, 2018
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
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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.
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
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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.
Nicholas Bock, France Van Wambeke, Moïra Dion, and Solange Duhamel
Biogeosciences, 15, 3909–3925, https://doi.org/10.5194/bg-15-3909-2018, https://doi.org/10.5194/bg-15-3909-2018, 2018
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We report the distribution of major nano- and pico-plankton groups in the western tropical South Pacific. We found microbial community structure to be typical of highly stratified regions of the open ocean, with significant contributions to total biomass by picophytoeukaryotes, and N2 fixation playing a central role in regulating ecosystem processes. Our results also suggest a reduction in the importance of predation in regulating bacteria populations under nutrient-limited conditions.
Dina Spungin, Natalia Belkin, Rachel A. Foster, Marcus Stenegren, Andrea Caputo, Mireille Pujo-Pay, Nathalie Leblond, Cécile Dupouy, Sophie Bonnet, and Ilana Berman-Frank
Biogeosciences, 15, 3893–3908, https://doi.org/10.5194/bg-15-3893-2018, https://doi.org/10.5194/bg-15-3893-2018, 2018
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The way marine organisms die can determine the fate of organic matter (OM) in the ocean. We investigated whether a form of auto-induced programmed cell death (PCD) influenced phytoplankton mortality and fate of OM. Our results from high biomass blooms of the cyanobacterium Trichodesmium show evidence for PCD and high production of sticky carbon material termed transparent exopolymeric particles (TEP) that facilitates cellular aggregation and enhances the vertical flux of OM to depth.
Mar Benavides, Katyanne M. Shoemaker, Pia H. Moisander, Jutta Niggemann, Thorsten Dittmar, Solange Duhamel, Olivier Grosso, Mireille Pujo-Pay, Sandra Hélias-Nunige, Alain Fumenia, and Sophie Bonnet
Biogeosciences, 15, 3107–3119, https://doi.org/10.5194/bg-15-3107-2018, https://doi.org/10.5194/bg-15-3107-2018, 2018
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We measured N2 fixation rates and identified diazotrophic phylotypes in the mesopelagic layer along a transect spanning from New Caledonia to French Polynesia. N2 fixation rates were low but consistently detected across all depths and stations. A distinct diazotrophic phylotype dominated at 650 dbar, coinciding with the oxygenated Subantarctic Mode Water (SAMW) and suggesting that the distribution of aphotic diazotroph communities is to some extent controlled by water mass structure.
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
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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.
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
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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
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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.
Louise Rousselet, Alain de Verneil, Andrea M. Doglioli, Anne A. Petrenko, Solange Duhamel, Christophe Maes, and Bruno Blanke
Biogeosciences, 15, 2411–2431, https://doi.org/10.5194/bg-15-2411-2018, https://doi.org/10.5194/bg-15-2411-2018, 2018
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The patterns of the large- and fine-scale surface circulation on biogeochemical and biological distributions are examined in the western tropical South Pacific (WTSP) in the context of the OUTPACE oceanographic cruise. The combined use of in situ and satellite data allows for the identification of water mass transport pathways and fine-scale structures, such as fronts, that drive surface distribution of tracers and microbial community structures.
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
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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
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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.
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
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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
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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
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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
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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
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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
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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).
Marc Tedetti, Lauriane Marie, Rüdiger Röttgers, Martine Rodier, France Van Wambeke, Sandra Helias, Mathieu Caffin, Véronique Cornet-Barthaux, and Cécile Dupouy
Biogeosciences, 13, 3283–3303, https://doi.org/10.5194/bg-13-3283-2016, https://doi.org/10.5194/bg-13-3283-2016, 2016
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In the framework of the VAHINE project, we investigated the spectral characteristics and the variability of dissolved and particulate chromophoric materials throughout a 23-day mesocosm experiment conducted in the south-west Pacific at the mouth of the New Caledonian coral lagoon. We found that the dynamics of CDOM and particulate matter absorption were strongly coupled with those of cyanobacteria Synechococcus spp. and bacterial production.
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
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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
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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.
Ulrike Pfreundt, France Van Wambeke, Mathieu Caffin, Sophie Bonnet, and Wolfgang R. Hess
Biogeosciences, 13, 2319–2337, https://doi.org/10.5194/bg-13-2319-2016, https://doi.org/10.5194/bg-13-2319-2016, 2016
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The Southwest Pacific has one of the highest N2 fixation rates in the global ocean, yet information is scarce on the bacterioplankton interrelationships. We detected high microbial diversity in the New Caledonia lagoon and inside a 50 000 L experimental enclosure of the same water mass over 3 weeks and give evidence for previously unknown niche partitioning. Phosphate fertilization promoted the growth of efficient N2 fixing cyanobacteria triggering the growth of most heterotrophic bacteria.
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
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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
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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.
U. Christaki, D. Lefèvre, C. Georges, J. Colombet, P. Catala, C. Courties, T. Sime-Ngando, S. Blain, and I. Obernosterer
Biogeosciences, 11, 6739–6753, https://doi.org/10.5194/bg-11-6739-2014, https://doi.org/10.5194/bg-11-6739-2014, 2014
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The concurrent investigation of several parameters has provided insight into two key roles of heterotrophic bacteria, and the microbial food web functioning, at the onset and late phase of the spring phytoplankton bloom induced by natural iron fertilization in the Southern Ocean.
Related subject area
Biodiversity and Ecosystem Function: Marine
Phytoplankton adaptation to steady or changing environments affects marine ecosystem functioning
Characterizing regional oceanography and bottom environmental conditions at two contrasting sponge grounds on the northern Labrador Shelf
Seasonal foraging behavior of Weddell seals in relation to oceanographic environmental conditions in the Ross Sea, Antarctica
Multifactorial effects of warming, low irradiance, and low salinity on Arctic kelps
Early life stages of fish under ocean alkalinity enhancement in coastal plankton communities
Planktonic foraminifera assemblage composition and flux dynamics inferred from an annual sediment trap record in the central Mediterranean Sea
Reefal ostracod assemblages from the Zanzibar Archipelago (Tanzania)
Growth response of Emiliania huxleyi to ocean alkalinity enhancement
Composite calcite and opal test in Foraminifera (Rhizaria)
Influence of oxygen minimum zone on macrobenthic community structure in the northern Benguela Upwelling System: a macro-nematode perspective
Simulated terrestrial runoff shifts the metabolic balance of a coastal Mediterranean plankton community towards heterotrophy
Contrasting carbon cycling in the benthic food webs between a river-fed, high-energy canyon and an upper continental slope
A critical trade-off between nitrogen quota and growth allows Coccolithus braarudii life cycle phases to exploit varying environment
Structural complexity and benthic metabolism: resolving the links between carbon cycling and biodiversity in restored seagrass meadows
Including the invisible: Deep depth-integrated chlorophyll estimates from remote sensing may assist in identifying biologically important areas in oligotrophic coastal margins
Building your own mountain: the effects, limits, and drawbacks of cold-water coral ecosystem engineering
Phytoplankton response to increased nickel in the context of ocean alkalinity enhancement
Diversity and density relationships between lebensspuren and tracemaking organisms: a study case from abyssal northwest Pacific
Technical note: An autonomous flow-through salinity and temperature perturbation mesocosm system for multi-stressor experiments
Reviews and syntheses: The clam before the storm – a meta-analysis showing the effect of combined climate change stressors on bivalves
A step towards measuring connectivity in the deep sea: elemental fingerprints of mollusk larval shells discriminate hydrothermal vent sites
Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, Gadus morhua: inherent and emergent density regulation
Bacterioplankton dark CO2 fixation in oligotrophic waters
The bottom mixed layer depth as an indicator of subsurface Chlorophyll a distribution
Ideas and perspectives: The fluctuating nature of oxygen shapes the ecology of aquatic habitats and their biogeochemical cycles – the aquatic oxyscape
Impact of deoxygenation and warming on global marine species in the 21st century
Ecological divergence of a mesocosm in an eastern boundary upwelling system assessed with multi-marker environmental DNA metabarcoding
Unique benthic foraminiferal communities (stained) in diverse environments of sub-Antarctic fjords, South Georgia
Upwelled plankton community modulates surface bloom succession and nutrient availability in a natural plankton assemblage
First phytoplankton community assessment of the Kong Håkon VII Hav, Southern Ocean, during austral autumn
Early life stages of a Mediterranean coral are vulnerable to ocean warming and acidification
Mediterranean seagrasses as carbon sinks: methodological and regional differences
Contrasting vertical distributions of recent planktic foraminifera off Indonesia during the southeast monsoon: implications for paleoceanographic reconstructions
The onset of the spring phytoplankton bloom in the coastal North Sea supports the Disturbance Recovery Hypothesis
Species richness and functional attributes of fish assemblages across a large-scale salinity gradient in shallow coastal areas
Modeling the growth and sporulation dynamics of the macroalga Ulva in mixed-age populations in cultivation and the formation of green tides
Spatial changes in community composition and food web structure of mesozooplankton across the Adriatic basin (Mediterranean Sea)
Predicting mangrove forest dynamics across a soil salinity gradient using an individual-based vegetation model linked with plant hydraulics
Will daytime community calcification reflect reef accretion on future, degraded coral reefs?
Modeling polar marine ecosystem functions guided by bacterial physiological and taxonomic traits
Quantifying functional consequences of habitat degradation on a Caribbean coral reef
Enhanced chlorophyll-a concentration in the wake of Sable Island, eastern Canada, revealed by two decades of satellite observations: a response to grey seal population dynamics?
Population dynamics and reproduction strategies of planktonic foraminifera in the open ocean
The Bouraké semi-enclosed lagoon (New Caledonia) – a natural laboratory to study the lifelong adaptation of a coral reef ecosystem to extreme environmental conditions
Atypical, high-diversity assemblages of foraminifera in a mangrove estuary in northern Brazil
Permanent ectoplasmic structures in deep-sea Cibicides and Cibicidoides taxa – long-term observations at in situ pressure
Ideas and perspectives: Ushering the Indian Ocean into the UN Decade of Ocean Science for Sustainable Development (UNDOSSD) through marine ecosystem research and operational services – an early career's take
Persistent effects of sand extraction on habitats and associated benthic communities in the German Bight
Spatial patterns of ectoenzymatic kinetics in relation to biogeochemical properties in the Mediterranean Sea and the concentration of the fluorogenic substrate used
A 2-decade (1988–2009) record of diatom fluxes in the Mauritanian coastal upwelling: impact of low-frequency forcing and a two-step shift in the species composition
Isabell Hochfeld and Jana Hinners
Biogeosciences, 21, 5591–5611, https://doi.org/10.5194/bg-21-5591-2024, https://doi.org/10.5194/bg-21-5591-2024, 2024
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Ecosystem models disagree on future changes in marine ecosystem functioning. We suspect that the lack of phytoplankton adaptation represents a major uncertainty factor, given the key role that phytoplankton play in marine ecosystems. Using an evolutionary ecosystem model, we found that phytoplankton adaptation can notably change simulated ecosystem dynamics. Future models should include phytoplankton adaptation; otherwise they can systematically overestimate future ecosystem-level changes.
Evert de Froe, Igor Yashayaev, Christian Mohn, Johanne Vad, Furu Mienis, Gerard Duineveld, Ellen Kenchington, Erica Head, Steve W. Ross, Sabena Blackbird, George A. Wolff, J. Murray Roberts, Barry MacDonald, Graham Tulloch, and Dick van Oevelen
Biogeosciences, 21, 5407–5433, https://doi.org/10.5194/bg-21-5407-2024, https://doi.org/10.5194/bg-21-5407-2024, 2024
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Deep-sea sponge grounds are distributed globally and are considered hotspots of biological diversity and biogeochemical cycling. To date, little is known about the environmental constraints that control where deep-sea sponge grounds occur and what conditions favour high sponge biomass. Here, we characterize oceanographic conditions at two contrasting sponge grounds. Our results imply that sponges and associated fauna benefit from strong tidal currents and favourable regional ocean currents.
Hyunjae Chung, Jikang Park, Mijin Park, Yejin Kim, Unyoung Chun, Sukyoung Yun, Won Sang Lee, Hyun A. Choi, Ji Sung Na, Seung-Tae Yoon, and Won Young Lee
Biogeosciences, 21, 5199–5217, https://doi.org/10.5194/bg-21-5199-2024, https://doi.org/10.5194/bg-21-5199-2024, 2024
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Understanding how marine animals adapt to variations in marine environmental conditions is paramount. In this paper, we investigated the influence of changes in seawater and light conditions on the seasonal foraging behavior of Weddell seals in the Ross Sea, Antarctica. Our findings could serve as a baseline and establish a foundational understanding for future research, particularly concerning the impact of marine environmental changes on the ecosystem of the Ross Sea Marine Protected Area.
Anaïs Lebrun, Cale A. Miller, Marc Meynadier, Steeve Comeau, Pierre Urrutti, Samir Alliouane, Robert Schlegel, Jean-Pierre Gattuso, and Frédéric Gazeau
Biogeosciences, 21, 4605–4620, https://doi.org/10.5194/bg-21-4605-2024, https://doi.org/10.5194/bg-21-4605-2024, 2024
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We tested the effects of warming, low salinity, and low irradiance on Arctic kelps. We show that growth rates were similar across species and treatments. Alaria esculenta is adapted to low-light conditions. Saccharina latissima exhibited nitrogen limitation, suggesting coastal erosion and permafrost thawing could be beneficial. Laminaria digitata did not respond to the treatments. Gene expression of Hedophyllum nigripes and S. latissima indicated acclimation to the experimental treatments.
Silvan Urs Goldenberg, Ulf Riebesell, Daniel Brüggemann, Gregor Börner, Michael Sswat, Arild Folkvord, Maria Couret, Synne Spjelkavik, Nicolás Sánchez, Cornelia Jaspers, and Marta Moyano
Biogeosciences, 21, 4521–4532, https://doi.org/10.5194/bg-21-4521-2024, https://doi.org/10.5194/bg-21-4521-2024, 2024
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Ocean alkalinity enhancement (OAE) is being evaluated as a carbon dioxide removal technology for climate change mitigation. With an experiment on species communities, we show that larval and juvenile fish can be resilient to the resulting perturbation of seawater. Fish may hence recruit successfully and continue to support fisheries' production in regions of OAE. Our findings help to establish an environmentally safe operating space for this ocean-based solution.
Thibauld M. Béjard, Andrés S. Rigual-Hernández, Javier P. Tarruella, José-Abel Flores, Anna Sanchez-Vidal, Irene Llamas-Cano, and Francisco J. Sierro
Biogeosciences, 21, 4051–4076, https://doi.org/10.5194/bg-21-4051-2024, https://doi.org/10.5194/bg-21-4051-2024, 2024
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The Mediterranean Sea is regarded as a climate change hotspot. Documenting the population of planktonic foraminifera is crucial. In the Sicily Channel, fluxes are higher during winter and positively linked with chlorophyll a concentration and cool temperatures. A comparison with other Mediterranean sites shows the transitional aspect of the studied zone. Finally, modern populations significantly differ from those in the sediment, highlighting a possible effect of environmental change.
Skye Yunshu Tian, Martin Langer, Moriaki Yasuhara, and Chih-Lin Wei
Biogeosciences, 21, 3523–3536, https://doi.org/10.5194/bg-21-3523-2024, https://doi.org/10.5194/bg-21-3523-2024, 2024
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Through the first large-scale study of meiobenthic ostracods from the diverse and productive reef ecosystem in the Zanzibar Archipelago, Tanzania, we found that the diversity and composition of ostracod assemblages as controlled by benthic habitats and human impacts were indicative of overall reef health, and we highlighted the usefulness of ostracods as a model proxy to monitor and understand the degradation of reef ecosystems from the coral-dominated phase to the algae-dominated phase.
Giulia Faucher, Mathias Haunost, Allanah Joy Paul, Anne Ulrike Christiane Tietz, and Ulf Riebesell
EGUsphere, https://doi.org/10.5194/egusphere-2024-2201, https://doi.org/10.5194/egusphere-2024-2201, 2024
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OAE is being evaluated for its capacity to absorb atmospheric CO2 in the ocean, storing it long-term to mitigate climate change. As researchers plan for field tests to gain practical insights into OAE, sharing knowledge on its environmental impact on marine ecosystems is urgent. Our study examined NaOH-induced alkalinity increases on Emiliania huxleyi, a key coccolithophore species. We found that to prevent negative impacts on this species, the increase in ΔTA should not exceed 600 µmol kg-1.
Julien Richirt, Satoshi Okada, Yoshiyuki Ishitani, Katsuyuki Uematsu, Akihiro Tame, Kaya Oda, Noriyuki Isobe, Toyoho Ishimura, Masashi Tsuchiya, and Hidetaka Nomaki
Biogeosciences, 21, 3271–3288, https://doi.org/10.5194/bg-21-3271-2024, https://doi.org/10.5194/bg-21-3271-2024, 2024
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We report the first benthic foraminifera with a composite test (i.e. shell) made of opal, which coats the inner part of the calcitic layer. Using comprehensive techniques, we describe the morphology and the composition of this novel opal layer and provide evidence that the opal is precipitated by the foraminifera itself. We explore the potential precipitation process and function(s) of this composite test and further discuss the possible implications for palaeoceanographic reconstructions.
Said Mohamed Hashim, Beth Wangui Waweru, and Agnes Muthumbi
Biogeosciences, 21, 2995–3006, https://doi.org/10.5194/bg-21-2995-2024, https://doi.org/10.5194/bg-21-2995-2024, 2024
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The study investigates the impact of decreasing oxygen in the ocean on macrofaunal communities using the BUS as an example. It identifies distinct shifts in community composition and feeding guilds across oxygen zones, with nematodes dominating dysoxic areas. These findings underscore the complex responses of benthic organisms to oxygen gradients, crucial for understanding ecosystem dynamics in hypoxic environments and their implications for marine biodiversity and sustainability.
Tanguy Soulié, Francesca Vidussi, Justine Courboulès, Marie Heydon, Sébastien Mas, Florian Voron, Carolina Cantoni, Fabien Joux, and Behzad Mostajir
Biogeosciences, 21, 1887–1902, https://doi.org/10.5194/bg-21-1887-2024, https://doi.org/10.5194/bg-21-1887-2024, 2024
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Due to climate change, it is projected that extreme rainfall events, which bring terrestrial matter into coastal seas, will occur more frequently in the Mediterranean region. To test the effects of runoffs of terrestrial matter on plankton communities from Mediterranean coastal waters, an in situ mesocosm experiment was conducted. The simulated runoff affected key processes mediated by plankton, such as primary production and respiration, suggesting major consequences of such events.
Chueh-Chen Tung, Yu-Shih Lin, Jian-Xiang Liao, Tzu-Hsuan Tu, James T. Liu, Li-Hung Lin, Pei-Ling Wang, and Chih-Lin Wei
Biogeosciences, 21, 1729–1756, https://doi.org/10.5194/bg-21-1729-2024, https://doi.org/10.5194/bg-21-1729-2024, 2024
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This study contrasts seabed food webs between a river-fed, high-energy canyon and the nearby slope. We show higher organic carbon (OC) flows through the canyon than the slope. Bacteria dominated the canyon, while seabed fauna contributed more to the slope food web. Due to frequent perturbation, the canyon had a lower faunal stock and OC recycling. Only 4 % of the seabed OC flux enters the canyon food web, suggesting a significant role of the river-fed canyon in transporting OC to the deep sea.
Joost de Vries, Fanny Monteiro, Gerald Langer, Colin Brownlee, and Glen Wheeler
Biogeosciences, 21, 1707–1727, https://doi.org/10.5194/bg-21-1707-2024, https://doi.org/10.5194/bg-21-1707-2024, 2024
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Calcifying phytoplankton (coccolithophores) utilize a life cycle in which they can grow and divide into two different phases. These two phases (HET and HOL) vary in terms of their physiology and distributions, with many unknowns about what the key differences are. Using a combination of lab experiments and model simulations, we find that nutrient storage is a critical difference between the two phases and that this difference allows them to inhabit different nitrogen input regimes.
Theodor Kindeberg, Karl Michael Attard, Jana Hüller, Julia Müller, Cintia Organo Quintana, and Eduardo Infantes
Biogeosciences, 21, 1685–1705, https://doi.org/10.5194/bg-21-1685-2024, https://doi.org/10.5194/bg-21-1685-2024, 2024
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Seagrass meadows are hotspots for biodiversity and productivity, and planting seagrass is proposed as a tool for mitigating biodiversity loss and climate change. We assessed seagrass planted in different years and found that benthic oxygen and carbon fluxes increased as the seabed developed from bare sediments to a mature seagrass meadow. This increase was partly linked to the diversity of colonizing algae which increased the light-use efficiency of the seagrass meadow community.
Renée P. Schoeman, Christine Erbe, and Robert D. McCauley
EGUsphere, https://doi.org/10.5194/egusphere-2024-859, https://doi.org/10.5194/egusphere-2024-859, 2024
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This study used ocean glider data to extend previously established relationships between surface and depth-integrated chlorophyll to an intermittent-oligotrophic continental margin. Relationships were established for stratified summer-transition months, stratified winter months, and mixed water columns. Integrations over twice the euphotic zone depth best captured Deep Chlorophyll Maxima contributing to a seasonal increase in depth-integrated chlorophyll likely relevant to higher trophic levels.
Anna-Selma van der Kaaden, Sandra R. Maier, Siluo Chen, Laurence H. De Clippele, Evert de Froe, Theo Gerkema, Johan van de Koppel, Furu Mienis, Christian Mohn, Max Rietkerk, Karline Soetaert, and Dick van Oevelen
Biogeosciences, 21, 973–992, https://doi.org/10.5194/bg-21-973-2024, https://doi.org/10.5194/bg-21-973-2024, 2024
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Combining hydrodynamic simulations and annotated videos, we separated which hydrodynamic variables that determine reef cover are engineered by cold-water corals and which are not. Around coral mounds, hydrodynamic zones seem to create a typical reef zonation, restricting corals from moving deeper (the expected response to climate warming). But non-engineered downward velocities in winter (e.g. deep winter mixing) seem more important for coral reef growth than coral engineering.
Xiaoke Xin, Giulia Faucher, and Ulf Riebesell
Biogeosciences, 21, 761–772, https://doi.org/10.5194/bg-21-761-2024, https://doi.org/10.5194/bg-21-761-2024, 2024
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Ocean alkalinity enhancement (OAE) is a promising approach to remove CO2 by accelerating natural rock weathering. However, some of the alkaline substances contain trace metals which could be toxic to marine life. By exposing three representative phytoplankton species to Ni released from alkaline materials, we observed varying responses of phytoplankton to nickel concentrations, suggesting caution should be taken and toxic thresholds should be avoided in OAE with Ni-rich materials.
Olmo Miguez-Salas, Angelika Brandt, Henry Knauber, and Torben Riehl
Biogeosciences, 21, 641–655, https://doi.org/10.5194/bg-21-641-2024, https://doi.org/10.5194/bg-21-641-2024, 2024
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In the deep sea, the interaction between benthic fauna (tracemakers) and substrate can be preserved as traces (i.e. lebensspuren), which are common features of seafloor landscapes, rendering them promising proxies for inferring biodiversity from marine images. No general correlation was observed between traces and benthic fauna. However, a local correlation was observed between specific stations depending on unknown tracemakers, tracemaker behaviour, and lebensspuren morphotypes.
Cale A. Miller, Pierre Urrutti, Jean-Pierre Gattuso, Steeve Comeau, Anaïs Lebrun, Samir Alliouane, Robert W. Schlegel, and Frédéric Gazeau
Biogeosciences, 21, 315–333, https://doi.org/10.5194/bg-21-315-2024, https://doi.org/10.5194/bg-21-315-2024, 2024
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This work describes an experimental system that can replicate and manipulate environmental conditions in marine or aquatic systems. Here, we show how the temperature and salinity of seawater delivered from a fjord is manipulated to experimental tanks on land. By constantly monitoring temperature and salinity in each tank via a computer program, the system continuously adjusts automated flow valves to ensure the seawater in each tank matches the targeted experimental conditions.
Rachel A. Kruft Welton, George Hoppit, Daniela N. Schmidt, James D. Witts, and Benjamin C. Moon
Biogeosciences, 21, 223–239, https://doi.org/10.5194/bg-21-223-2024, https://doi.org/10.5194/bg-21-223-2024, 2024
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We conducted a meta-analysis of known experimental literature examining how marine bivalve growth rates respond to climate change. Growth is usually negatively impacted by climate change. Bivalve eggs/larva are generally more vulnerable than either juveniles or adults. Available data on the bivalve response to climate stressors are biased towards early growth stages (commercially important in the Global North), and many families have only single experiments examining climate change impacts.
Vincent Mouchi, Christophe Pecheyran, Fanny Claverie, Cécile Cathalot, Marjolaine Matabos, Yoan Germain, Olivier Rouxel, Didier Jollivet, Thomas Broquet, and Thierry Comtet
Biogeosciences, 21, 145–160, https://doi.org/10.5194/bg-21-145-2024, https://doi.org/10.5194/bg-21-145-2024, 2024
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The impact of deep-sea mining will depend critically on the ability of larval dispersal of hydrothermal mollusks to connect and replenish natural populations. However, assessing connectivity is extremely challenging, especially in the deep sea. Here, we investigate the potential of using the chemical composition of larval shells to discriminate larval origins between multiple hydrothermal sites in the southwest Pacific. Our results confirm that this method can be applied with high accuracy.
Anna-Marie Winter, Nadezda Vasilyeva, and Artem Vladimirov
Biogeosciences, 20, 3683–3716, https://doi.org/10.5194/bg-20-3683-2023, https://doi.org/10.5194/bg-20-3683-2023, 2023
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There is an increasing number of fish in poor state, and many do not recover, even when fishing pressure is ceased. An Allee effect can hinder population recovery because it suppresses the fish's productivity at low abundance. With a model fitted to 17 Atlantic cod stocks, we find that ocean warming and fishing can cause an Allee effect. If present, the Allee effect hinders fish recovery. This shows that Allee effects are dynamic, not uncommon, and calls for precautionary management measures.
Afrah Alothman, Daffne López-Sandoval, Carlos M. Duarte, and Susana Agustí
Biogeosciences, 20, 3613–3624, https://doi.org/10.5194/bg-20-3613-2023, https://doi.org/10.5194/bg-20-3613-2023, 2023
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This study investigates bacterial dissolved inorganic carbon (DIC) fixation in the Red Sea, an oligotrophic ecosystem, using stable-isotope labeling and spectroscopy. The research reveals that bacterial DIC fixation significantly contributes to total DIC fixation, in the surface and deep water. The study demonstrates that as primary production decreases, the role of bacterial DIC fixation increases, emphasizing its importance with photosynthesis in estimating oceanic carbon dioxide production.
Arianna Zampollo, Thomas Cornulier, Rory O'Hara Murray, Jacqueline Fiona Tweddle, James Dunning, and Beth E. Scott
Biogeosciences, 20, 3593–3611, https://doi.org/10.5194/bg-20-3593-2023, https://doi.org/10.5194/bg-20-3593-2023, 2023
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This paper highlights the use of the bottom mixed layer depth (BMLD: depth between the end of the pycnocline and the mixed layer below) to investigate subsurface Chlorophyll a (a proxy of primary production) in temperate stratified shelf waters. The strict correlation between subsurface Chl a and BMLD becomes relevant in shelf-productive waters where multiple stressors (e.g. offshore infrastructure) will change the stratification--mixing balance and related carbon fluxes.
Marco Fusi, Sylvain Rigaud, Giovanna Guadagnin, Alberto Barausse, Ramona Marasco, Daniele Daffonchio, Julie Régis, Louison Huchet, Capucine Camin, Laura Pettit, Cristina Vina-Herbon, and Folco Giomi
Biogeosciences, 20, 3509–3521, https://doi.org/10.5194/bg-20-3509-2023, https://doi.org/10.5194/bg-20-3509-2023, 2023
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Oxygen availability in marine water and freshwater is very variable at daily and seasonal scales. The dynamic nature of oxygen fluctuations has important consequences for animal and microbe physiology and ecology, yet it is not fully understood. In this paper, we showed the heterogeneous nature of the aquatic oxygen landscape, which we defined here as the
oxyscape, and we addressed the importance of considering the oxyscape in the modelling and managing of aquatic ecosystems.
Anne L. Morée, Tayler M. Clarke, William W. L. Cheung, and Thomas L. Frölicher
Biogeosciences, 20, 2425–2454, https://doi.org/10.5194/bg-20-2425-2023, https://doi.org/10.5194/bg-20-2425-2023, 2023
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Ocean temperature and oxygen shape marine habitats together with species’ characteristics. We calculated the impacts of projected 21st-century warming and oxygen loss on the contemporary habitat volume of 47 marine species and described the drivers of these impacts. Most species lose less than 5 % of their habitat at 2 °C of global warming, but some species incur losses 2–3 times greater than that. We also calculate which species may be most vulnerable to climate change and why this is the case.
Markus A. Min, David M. Needham, Sebastian Sudek, Nathan Kobun Truelove, Kathleen J. Pitz, Gabriela M. Chavez, Camille Poirier, Bente Gardeler, Elisabeth von der Esch, Andrea Ludwig, Ulf Riebesell, Alexandra Z. Worden, and Francisco P. Chavez
Biogeosciences, 20, 1277–1298, https://doi.org/10.5194/bg-20-1277-2023, https://doi.org/10.5194/bg-20-1277-2023, 2023
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Emerging molecular methods provide new ways of understanding how marine communities respond to changes in ocean conditions. Here, environmental DNA was used to track the temporal evolution of biological communities in the Peruvian coastal upwelling system and in an adjacent enclosure where upwelling was simulated. We found that the two communities quickly diverged, with the open ocean being one found during upwelling and the enclosure evolving to one found under stratified conditions.
Wojciech Majewski, Witold Szczuciński, and Andrew J. Gooday
Biogeosciences, 20, 523–544, https://doi.org/10.5194/bg-20-523-2023, https://doi.org/10.5194/bg-20-523-2023, 2023
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We studied foraminifera living in the fjords of South Georgia, a sub-Antarctic island sensitive to climate change. As conditions in water and on the seafloor vary, different associations of these microorganisms dominate far inside, in the middle, and near fjord openings. Assemblages in inner and middle parts of fjords are specific to South Georgia, but they may become widespread with anticipated warming. These results are important for interpretating fossil records and monitoring future change.
Allanah Joy Paul, Lennart Thomas Bach, Javier Arístegui, Elisabeth von der Esch, Nauzet Hernández-Hernández, Jonna Piiparinen, Laura Ramajo, Kristian Spilling, and Ulf Riebesell
Biogeosciences, 19, 5911–5926, https://doi.org/10.5194/bg-19-5911-2022, https://doi.org/10.5194/bg-19-5911-2022, 2022
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We investigated how different deep water chemistry and biology modulate the response of surface phytoplankton communities to upwelling in the Peruvian coastal zone. Our results show that the most influential drivers were the ratio of inorganic nutrients (N : P) and the microbial community present in upwelling source water. These led to unexpected and variable development in the phytoplankton assemblage that could not be predicted by the amount of inorganic nutrients alone.
Hanna M. Kauko, Philipp Assmy, Ilka Peeken, Magdalena Różańska-Pluta, Józef M. Wiktor, Gunnar Bratbak, Asmita Singh, Thomas J. Ryan-Keogh, and Sebastien Moreau
Biogeosciences, 19, 5449–5482, https://doi.org/10.5194/bg-19-5449-2022, https://doi.org/10.5194/bg-19-5449-2022, 2022
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This article studies phytoplankton (microscopic
plantsin the ocean capable of photosynthesis) in Kong Håkon VII Hav in the Southern Ocean. Different species play different roles in the ecosystem, and it is therefore important to assess the species composition. We observed that phytoplankton blooms in this area are formed by large diatoms with strong silica armors, which can lead to high silica (and sometimes carbon) export to depth and be important prey for krill.
Chloe Carbonne, Steeve Comeau, Phoebe T. W. Chan, Keyla Plichon, Jean-Pierre Gattuso, and Núria Teixidó
Biogeosciences, 19, 4767–4777, https://doi.org/10.5194/bg-19-4767-2022, https://doi.org/10.5194/bg-19-4767-2022, 2022
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For the first time, our study highlights the synergistic effects of a 9-month warming and acidification combined stress on the early life stages of a Mediterranean azooxanthellate coral, Astroides calycularis. Our results predict a decrease in dispersion, settlement, post-settlement linear extention, budding and survival under future global change and that larvae and recruits of A. calycularis are stages of interest for this Mediterranean coral resistance, resilience and conservation.
Iris E. Hendriks, Anna Escolano-Moltó, Susana Flecha, Raquel Vaquer-Sunyer, Marlene Wesselmann, and Núria Marbà
Biogeosciences, 19, 4619–4637, https://doi.org/10.5194/bg-19-4619-2022, https://doi.org/10.5194/bg-19-4619-2022, 2022
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Seagrasses are marine plants with the capacity to act as carbon sinks due to their high primary productivity, using carbon for growth. This capacity can play a key role in climate change mitigation. We compiled and published data showing that two Mediterranean seagrass species have different metabolic rates, while the study method influences the rates of the measurements. Most communities act as carbon sinks, while the western basin might be more productive than the eastern Mediterranean.
Raúl Tapia, Sze Ling Ho, Hui-Yu Wang, Jeroen Groeneveld, and Mahyar Mohtadi
Biogeosciences, 19, 3185–3208, https://doi.org/10.5194/bg-19-3185-2022, https://doi.org/10.5194/bg-19-3185-2022, 2022
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We report census counts of planktic foraminifera in depth-stratified plankton net samples off Indonesia. Our results show that the vertical distribution of foraminifera species routinely used in paleoceanographic reconstructions varies in hydrographically distinct regions, likely in response to food availability. Consequently, the thermal gradient based on mixed layer and thermocline dwellers also differs for these regions, suggesting potential implications for paleoceanographic reconstructions.
Ricardo González-Gil, Neil S. Banas, Eileen Bresnan, and Michael R. Heath
Biogeosciences, 19, 2417–2426, https://doi.org/10.5194/bg-19-2417-2022, https://doi.org/10.5194/bg-19-2417-2022, 2022
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In oceanic waters, the accumulation of phytoplankton biomass in winter, when light still limits growth, is attributed to a decrease in grazing as the mixed layer deepens. However, in coastal areas, it is not clear whether winter biomass can accumulate without this deepening. Using 21 years of weekly data, we found that in the Scottish coastal North Sea, the seasonal increase in light availability triggers the accumulation of phytoplankton biomass in winter, when light limitation is strongest.
Birgit Koehler, Mårten Erlandsson, Martin Karlsson, and Lena Bergström
Biogeosciences, 19, 2295–2312, https://doi.org/10.5194/bg-19-2295-2022, https://doi.org/10.5194/bg-19-2295-2022, 2022
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Understanding species richness patterns remains a challenge for biodiversity management. We estimated fish species richness over a coastal salinity gradient (3–32) with a method that allowed comparing data from various sources. Species richness was 3-fold higher at high vs. low salinity, and salinity influenced species’ habitat preference, mobility and feeding type. If climate change causes upper-layer freshening of the Baltic Sea, further shifts along the identified patterns may be expected.
Uri Obolski, Thomas Wichard, Alvaro Israel, Alexander Golberg, and Alexander Liberzon
Biogeosciences, 19, 2263–2271, https://doi.org/10.5194/bg-19-2263-2022, https://doi.org/10.5194/bg-19-2263-2022, 2022
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The algal genus Ulva plays a major role in coastal ecosystems worldwide and is a promising prospect as an seagriculture crop. A substantial hindrance to cultivating Ulva arises from sudden sporulation, leading to biomass loss. This process is not yet well understood. Here, we characterize the dynamics of Ulva growth, considering the potential impact of sporulation inhibitors, using a mathematical model. Our findings are an essential step towards understanding the dynamics of Ulva growth.
Emanuela Fanelli, Samuele Menicucci, Sara Malavolti, Andrea De Felice, and Iole Leonori
Biogeosciences, 19, 1833–1851, https://doi.org/10.5194/bg-19-1833-2022, https://doi.org/10.5194/bg-19-1833-2022, 2022
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Zooplankton play a key role in marine ecosystems, forming the base of the marine food web and a link between primary producers and higher-order consumers, such as fish. This aspect is crucial in the Adriatic basin, one of the most productive and overexploited areas of the Mediterranean Sea. A better understanding of community and food web structure and their response to water mass changes is essential under a global warming scenario, as zooplankton are sensitive to climate change.
Masaya Yoshikai, Takashi Nakamura, Rempei Suwa, Sahadev Sharma, Rene Rollon, Jun Yasuoka, Ryohei Egawa, and Kazuo Nadaoka
Biogeosciences, 19, 1813–1832, https://doi.org/10.5194/bg-19-1813-2022, https://doi.org/10.5194/bg-19-1813-2022, 2022
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This study presents a new individual-based vegetation model to investigate salinity control on mangrove productivity. The model incorporates plant hydraulics and tree competition and predicts unique and complex patterns of mangrove forest structures that vary across soil salinity gradients. The presented model does not hold an empirical expression of salinity influence on productivity and thus may provide a better understanding of mangrove forest dynamics in future climate change.
Coulson A. Lantz, William Leggat, Jessica L. Bergman, Alexander Fordyce, Charlotte Page, Thomas Mesaglio, and Tracy D. Ainsworth
Biogeosciences, 19, 891–906, https://doi.org/10.5194/bg-19-891-2022, https://doi.org/10.5194/bg-19-891-2022, 2022
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Coral bleaching events continue to drive the degradation of coral reefs worldwide. In this study we measured rates of daytime coral reef community calcification and photosynthesis during a reef-wide bleaching event. Despite a measured decline in coral health across several taxa, there was no change in overall daytime community calcification and photosynthesis. These findings highlight potential limitations of these community-level metrics to reflect actual changes in coral health.
Hyewon Heather Kim, Jeff S. Bowman, Ya-Wei Luo, Hugh W. Ducklow, Oscar M. Schofield, Deborah K. Steinberg, and Scott C. Doney
Biogeosciences, 19, 117–136, https://doi.org/10.5194/bg-19-117-2022, https://doi.org/10.5194/bg-19-117-2022, 2022
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Heterotrophic marine bacteria are tiny organisms responsible for taking up organic matter in the ocean. Using a modeling approach, this study shows that characteristics (taxonomy and physiology) of bacteria are associated with a subset of ecological processes in the coastal West Antarctic Peninsula region, a system susceptible to global climate change. This study also suggests that bacteria will become more active, in particular large-sized cells, in response to changing climates in the region.
Alice E. Webb, Didier M. de Bakker, Karline Soetaert, Tamara da Costa, Steven M. A. C. van Heuven, Fleur C. van Duyl, Gert-Jan Reichart, and Lennart J. de Nooijer
Biogeosciences, 18, 6501–6516, https://doi.org/10.5194/bg-18-6501-2021, https://doi.org/10.5194/bg-18-6501-2021, 2021
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The biogeochemical behaviour of shallow reef communities is quantified to better understand the impact of habitat degradation and species composition shifts on reef functioning. The reef communities investigated barely support reef functions that are usually ascribed to conventional coral reefs, and the overall biogeochemical behaviour is found to be similar regardless of substrate type. This suggests a decrease in functional diversity which may therefore limit services provided by this reef.
Emmanuel Devred, Andrea Hilborn, and Cornelia Elizabeth den Heyer
Biogeosciences, 18, 6115–6132, https://doi.org/10.5194/bg-18-6115-2021, https://doi.org/10.5194/bg-18-6115-2021, 2021
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A theoretical model of grey seal seasonal abundance on Sable Island (SI) coupled with chlorophyll-a concentration [chl-a] measured by satellite revealed the impact of seal nitrogen fertilization on the surrounding waters of SI, Canada. The increase in seals from about 100 000 in 2003 to about 360 000 in 2018 during the breeding season is consistent with an increase in [chl-a] leeward of SI. The increase in seal abundance explains 8 % of the [chl-a] increase.
Julie Meilland, Michael Siccha, Maike Kaffenberger, Jelle Bijma, and Michal Kucera
Biogeosciences, 18, 5789–5809, https://doi.org/10.5194/bg-18-5789-2021, https://doi.org/10.5194/bg-18-5789-2021, 2021
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Planktonic foraminifera population dynamics has long been assumed to be controlled by synchronous reproduction and ontogenetic vertical migration (OVM). Due to contradictory observations, this concept became controversial. We here test it in the Atlantic ocean for four species of foraminifera representing the main clades. Our observations support the existence of synchronised reproduction and OVM but show that more than half of the population does not follow the canonical trajectory.
Federica Maggioni, Mireille Pujo-Pay, Jérome Aucan, Carlo Cerrano, Barbara Calcinai, Claude Payri, Francesca Benzoni, Yves Letourneur, and Riccardo Rodolfo-Metalpa
Biogeosciences, 18, 5117–5140, https://doi.org/10.5194/bg-18-5117-2021, https://doi.org/10.5194/bg-18-5117-2021, 2021
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Based on current experimental evidence, climate change will affect up to 90 % of coral reefs worldwide. The originality of this study arises from our recent discovery of an exceptional study site where environmental conditions (temperature, pH, and oxygen) are even worse than those forecasted for the future.
While these conditions are generally recognized as unfavorable for marine life, we found a rich and abundant coral reef thriving under such extreme environmental conditions.
Nisan Sariaslan and Martin R. Langer
Biogeosciences, 18, 4073–4090, https://doi.org/10.5194/bg-18-4073-2021, https://doi.org/10.5194/bg-18-4073-2021, 2021
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Analyses of foraminiferal assemblages from the Mamanguape mangrove estuary (northern Brazil) revealed highly diverse, species-rich, and structurally complex biotas. The atypical fauna resembles shallow-water offshore assemblages and are interpreted to be the result of highly saline ocean waters penetrating deep into the estuary. The findings contrast with previous studies, have implications for the fossil record, and provide novel perspectives for reconstructing mangrove environments.
Jutta E. Wollenburg, Jelle Bijma, Charlotte Cremer, Ulf Bickmeyer, and Zora Mila Colomba Zittier
Biogeosciences, 18, 3903–3915, https://doi.org/10.5194/bg-18-3903-2021, https://doi.org/10.5194/bg-18-3903-2021, 2021
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Cultured at in situ high-pressure conditions Cibicides and Cibicidoides taxa develop lasting ectoplasmic structures that cannot be retracted or resorbed. An ectoplasmic envelope surrounds their test and may protect the shell, e.g. versus carbonate aggressive bottom water conditions. Ectoplasmic roots likely anchor the specimens in areas of strong bottom water currents, trees enable them to elevate themselves above ground, and twigs stabilize and guide the retractable pseudopodial network.
Kumar Nimit
Biogeosciences, 18, 3631–3635, https://doi.org/10.5194/bg-18-3631-2021, https://doi.org/10.5194/bg-18-3631-2021, 2021
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The Indian Ocean Rim hosts many of the underdeveloped and emerging economies that depend on ocean resources for the livelihood of millions. Operational ocean information services cater to the requirements of resource managers and end-users to efficiently harness resources, mitigate threats and ensure safety. This paper outlines existing tools and explores the ongoing research that has the potential to convert the findings into operational services in the near- to midterm.
Finn Mielck, Rune Michaelis, H. Christian Hass, Sarah Hertel, Caroline Ganal, and Werner Armonies
Biogeosciences, 18, 3565–3577, https://doi.org/10.5194/bg-18-3565-2021, https://doi.org/10.5194/bg-18-3565-2021, 2021
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Marine sand mining is becoming more and more important to nourish fragile coastlines that face global change. We investigated the largest sand extraction site in the German Bight. The study reveals that after more than 35 years of mining, the excavation pits are still detectable on the seafloor while the sediment composition has largely changed. The organic communities living in and on the seafloor were strongly decimated, and no recovery is observable towards previous conditions.
France Van Wambeke, Elvira Pulido, Philippe Catala, Julie Dinasquet, Kahina Djaoudi, Anja Engel, Marc Garel, Sophie Guasco, Barbara Marie, Sandra Nunige, Vincent Taillandier, Birthe Zäncker, and Christian Tamburini
Biogeosciences, 18, 2301–2323, https://doi.org/10.5194/bg-18-2301-2021, https://doi.org/10.5194/bg-18-2301-2021, 2021
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Michaelis–Menten kinetics were determined for alkaline phosphatase, aminopeptidase and β-glucosidase in the Mediterranean Sea. Although the ectoenzymatic-hydrolysis contribution to heterotrophic prokaryotic needs was high in terms of N, it was low in terms of C. This study points out the biases in interpretation of the relative differences in activities among the three tested enzymes in regard to the choice of added concentrations of fluorogenic substrates.
Oscar E. Romero, Simon Ramondenc, and Gerhard Fischer
Biogeosciences, 18, 1873–1891, https://doi.org/10.5194/bg-18-1873-2021, https://doi.org/10.5194/bg-18-1873-2021, 2021
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Upwelling intensity along NW Africa varies on the interannual to decadal timescale. Understanding its changes is key for the prediction of future changes of CO2 sequestration in the northeastern Atlantic. Based on a multiyear (1988–2009) sediment trap experiment at the site CBmeso, fluxes and the species composition of the diatom assemblage are presented. Our data help in establishing the scientific basis for forecasting and modeling future states of this ecosystem and its decadal changes.
Cited articles
Alonso-Saez, L., Gasol, J. M., Aristegui, J., Vilas, J. C., Vaque, D.,
Duarte, C. M., and Agusti, S.: Large scale variability in surface bacterial
carbon demand and growth efficiency in the subtropical northeast Atlantic
Ocean, Limnol. Oceanogr., 52, 533–546, 2007.
Alonso-Saez, L., Vasquez-Dominguez, E., Cardelus, C., Pinhassi, J.,
Montserrat Sala, M., Lekunberri, I., Balagué, V., Vila-Costa, M., Unrein,
F., Massana, R., Simo, R., and Gasol, J.: Leucine to carbon empirical
conversion factor experiments: does bacterial community structure have an
influence?, Environ. Microbiol., 12, 2988–2997, 2010.
Aranguren-Gassis, M., Serret, P., Fernández, E., Herrera, J. L.,
Dominguez, J. F., Perez, V., and Escanez, J.: Balanced plankton net community
metabolism in the oligotrophic North Atlantic subtropical gyre from
Lagrangian observations, Deep-Sea Res. Pt. I, 68, 116–122, 2012a.
Aranguren-Gassis, M., Teira, E., Serret, P., Martínez-García, M.,
and Fernández, E.: Potential overestimation of bacterial respiration
rates in oligotrophic plankton communities, Mar. Ecol. Prog. Ser., 453,
1–10, 2012b.
Benavides, M., Moisander, P., Berthelot, H., Dittmar, T., Grosso, O., and
Bonnet, S.: Mesopelagic N2 Fixation Related to Organic Matter
Composition in the Solomon and Bismarck Seas (Southwest Pacific), Plos One,
10, e0143775, https://doi.org/10.1371/journal.pone.0143775, 2015.
Benavides, M., Shoemaker, K. M., Moisander, P. H., Niggemann, J., Dittmar,
T., Duhamel, S., Grosso, O., Pujo-Pay, M., Hélias-Nunige, S., and Bonnet,
S.: Aphotic N2 fixation along an oligotrophic to ultraoligotrophic
transect in the Western Tropical South Pacific Ocean, Biogeosciences
Discuss., doi.org/10.5194/bg-2017-542, in press, 2018.
Bench, S. R., Frank, I., Robidart, J., and Zehr, J. P.: Two subpopulations of
Crocosphaera watsonii have distinct distributions in the North and South
Pacific, Environ. Microbiol., 18, 514–524, 2016.
Berthelot, H., Moutin, T., L'Helguen, S., Leblanc, K., Hélias, S.,
Grosso, O., Leblond, N., Charrière, B., and Bonnet, S.: Dinitrogen
fixation and dissolved organic nitrogen fueled primary production and
particulate export during the VAHINE mesocosm experiment (New Caledonia
lagoon), Biogeosciences, 12, 4099–4112,
https://doi.org/10.5194/bg-12-4099-2015, 2015.
Berthelot, H., Bonnet, S., Grosso, O., Cornet, V., and Barani, A.: Transfer
of diazotroph-derived nitrogen towards non-diazotrophic planktonic
communities: a comparative study between Trichodesmium erythraeum,
Crocosphaera watsonii and Cyanothece sp., Biogeosciences,
13, 4005–4021, 2016.
Bonnet, S., Dekaezemacker, J., Turk-Kubo, K. A., Moutin, T., Hamersley, R.
M., Grosso, O., Zehr, J. P., and Capone, D. G.: Aphotic N2 Fixation in the
Eastern Tropical South Pacific Ocean, PLoS ONE, 8, e81265,
https://doi.org/10.1371/journal.pone.0081265, 2013.
Bonnet, S., Berthelot, H., Turk-Kubo, K. A., Cornet-Barthaux, V., Fawcett,
S., Berman-Frank, I., Barani, A., Grégori, G., Dekaezemacker, J.,
Benavides, M., and Capone, D. G.: Diazotroph derived nitrogen supports diatom
growth in the South West Pacific: A quantitative study using nanoSIMS,
Limnol. Oceanogr., 61, 1549–1562, https://doi.org/10.1002/lno.10300, 2016.
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, PNAS Letter, 114,
E2800–E2801, doi/10.1073/pnas.1619514114, 2017.
Bonnet, S., Caffin, M., Berthelot, H., Grosso, O., Benavides, M.,
Helias-Nuninge, H., Guieu, C., Stenegren, M. and Foster, R.: In depth
characterization of diazotroph activity across the Western Tropical South
Pacific hot spot of N2 fixation, Biogeosciences Discuss.,
doi.org/10.5194/bg-2017-567, 2018.
Bouruet-Aubertot, P., Cuypers, Y., Doglioli, A., Caffin, M., Yohia, C., de
Verneil, A., Petrenko, A., Lefèvre, D., Le Goff, H., Rougier, G.,
Picheral, M., and Moutin, T.: Longitudinal contrast in Turbulence along a
∼ 19S section in the Pacific and its consequences on biogeochemical
fluxes, Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-170, in review, 2018.
Caffin, M., Moutin, T., Foster, R. A., Bouruet-Aubertot, P., Doglioli, A. M.,
Berthelot, H., Grosso, O., Helias-Nunige, S., Leblond, N., Gimenez, A.,
Petrenko, A. A., de Verneil, A., and Bonnet, S.: Nitrogen budgets following a
Lagrangian strategy in the Western Tropical South Pacific Ocean: the
prominent role of N2 fixation (OUTPACE cruise), Biogeosciences Discuss.,
https://doi.org/10.5194/bg-2017-468, in press, 2018.
Carlson, C. A. and Hansell, D. A.: DOM sources, sinks, reactivity and
budgets, in: Biogeochemistry of Marine Dissolved organic matter, 2nd Edn.,
edited by: Hansell, D. A. and Carlson, C. A., Academic Press, Chapter, 3,
66–95, 2015.
Claustre, H., Huot, Y., Obernosterer, I., Gentili, B., Tailliez, D., and
Lewis, M.: Gross community production and metabolic balance in the South
Pacific Gyre, using a non intrusive bio-optical method, Biogeosciences, 5,
463–474, doi.org/10.5194/bg-5-463-2008, 2008a.
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, 2008b.
Cauwet, G.: Determination of dissolved organic carbon (DOC) and nitrogen
(DON) by high temperature combustion, in: Methods ofseawater analysis, 3rd
Edn., edited by: Grashoff, K., Kremling, K., and Ehrhard, M., 407–420, 1999.
Cole, J. J., Findlay, S., and Pace, M. L.: Bacterial production in fresh and
saltwater ecosystems: a cross – system overview, Mar. Ecol. Prog. Ser., 43,
1–10, 1988.
Dekaezemacker, J., Bonnet, S., Grosso, O., Moutin, T., Bressac, M., and
Capone, D. G.: Evidence of active dinitrogen fixation in surface waters of
the eastern tropical South Pacific during El Niño and La Niña events
and evaluation of its potential nutrient controls, Global Biogeochem. Cy.,
27, 1–12, 2013.
del Giorgio, P. and Duarte, C.: Respiration in the open ocean, Nature, 420,
379–384, 2002.
de Verneil, A., Rousselet, L., Doglioli, A. M., Petrenko, A. A., and Moutin,
T.: The fate of a southwest Pacific bloom: gauging the impact of submesoscale
vs. mesoscale circulation on biological gradients in the subtropics,
Biogeosciences, 14, 3471–3486, doi.org/10.5194/bg-14-3471-2017, 2017.
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.
Duarte, C. M., Regaudie-de-Gioux, A., Arrieta, J. M., Delgado-Huertas, A.,
and Agustí, S.: The Oligotrophic Ocean Is Heterotrophic, Ann. Rev. Mar.
Sci., 5, 551–569, 2013.
Ducklow, H. W. and Doney, S. C.: What is the metabolic state of the
oligotrophic ocean? A debate, Ann. Rev. Mar. Sci., 5, 525–533, 2013.
Duhamel, S., Zeman, F., and Moutin, T.: A dual-labeling method for the
simultaneous measurement of dissolved inorganic carbon and phosphate uptake
by marine planktonic species, Limnol. Oceanogr. Methods, 4, 416–425, 2006.
Duhamel, S., Van Wambeke, F., Lefevre, D., Benavides, M., and Bonnet, S.:
Mixotrophic metabolism by natural communities of unicellular cyanobacteria in
the western tropical South Pacific Ocean, Environ. Microbiol. Rep., in press,
https://doi.org/10.1111/1462-2920.14111, 2018.
Dupouy, C., Petit, M., and Dandonneau, Y.: Satellite detected cyanobacteria
bloom in the southwestern tropical Pacific, Implication for nitrogen
fixation, Int. J. Remote Sens., 8, 389–396, 1988.
Dupouy, C., Benielli-Gary, D., Neveux, J., Dandonneau, Y., and Westberry, T.
K.: An algorithm for detecting Trichodesmium surface bloom in the
South Western Tropical Pacific, Biogeosciences, 8, 3631–3647,
https://doi.org/10.5194/bg-8-3631-2011, 2011.
Dupouy, C., Frouin, R., Tedetti, M., Maillard, M., Rodier, M., Lombard, F.,
Guidi, L., Picheral, M., Duhamel, S., Charrière, B., and
Sempéré, R.: diazotrophic Trichodesmium influences ocean
color and pigment composition in the South West tropical Pacific,
Biogeosciences Discuss., doi.org/10.5194/bg-2017-570, in review, 2018.
Eichner, M. J., Klawonn, I., Wilson, S. T., Littmann, S., Whitehouse, M. J.,
Church, M. J., Kuypers, M. M., Karl, D. M., and Ploug, H.: Chemical
microenvironments and single-cell carbon and nitrogen uptake in
field-collected colonies of Trichodesmium under different pCO2,
ISME J., 11, 1305–1317 2017.
Fonseca-Batista, D., Dehairs, F., Riou, V., Fripiat, F., Elskens, M., Deman,
F., Brion, N., Quéroué, F., Bode, B., and Auel, H.: Nitrogen fixation
in the eastern Atlantic reaches similar levels in the Southern and Northern
Hemisphere, J. Geophys. Res.-Ocean., 122, 587–601, 2016.
Foster, R. A., Kuypers, M. M., Vagner, T., Pearl, R. W., Musat, N., and Zehr,
J. P.: Nitrogen fixation and transfer in open ocean diatom–cyanobacterial
symbioses, ISME J., 5, 184–1493, 2011.
Fouilland, E. and Mostajir, B.: Revisited phytoplanktonic carbon
dependencyof heterotrophic bacteria infreshwaters, transitional, coastal and
oceanic waters, FEMS Microbiol. Ecol., 73, 419–429, 2010.
Ganachaud, A., Cravatte, S., Sprintall, J., Germineaud, C., Marion Alberty,
M., Jeandel, C., Eldin, G., Metzl, N., Bonnet, S., Benavides, M., Heimburger,
L.-E., Lefèvre, J., Michael, S., Resing, J., Quéroué, F.,
Sarthou, G., Rodier, Berthelot, H., Baurand, F., Grelet, J., Hasegawa, T.,
Kessler, W., Kilepak, M., Lacan, F., Privat, E., Send, U., Van Beek, P.,
Souhaut, S., and Sonke, J. E.: The Solomon Sea: its circulation, chemistry,
geochemistry and biology explored during two oceanographic cruises, Elem.
Sci. Anth., 5, 33, https://doi.org/10.1525/elementa.221, 2017.
Garcia, N., Raimbault, P., and Sandroni, V.: Seasonal nitrogen fixation and
primary production in the Southwest Pacific: nanoplankton diazotrophy and
transfer of nitrogen to picoplankton organisms, Mar. Ecol. Prog. Ser., 343,
25–33, 2007.
Gasol, J. M., Pinhassi, J., Alonso-Sáez, L., Ducklow, H., Herndl, G. J.,
Koblízek, M., Labrenz, M., Luo, Y., Morán, X. A., Reinthaler, T.,
and Simon, M.: Towards a better understanding of microbial carbon flux in the
sea, Aquat. Microb. Ecol., 53, 21–38, 2008.
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.
Gradoville, M. R., Bombar, D., Crump, B. C., Letelier, R. M., Zehr, J. P.,
and White, A. E.: Diversity and activity of nitrogen-fixing communities
across ocean basins, Limnol. Oceanogr., 62, 1895–1909, 2017.
Gruber, N.: Elusive marine nitrogen fixation, PNAS, 113, 4246–4248, 2016.
Halm, H., Lam, P., Ferdelman, T. G., Lavik, G., Dittmar, T., LaRoche, J.,
D'Hondt, S., and Kuypers, M. M.: Heterotrophic organisms dominate nitrogen
fixation in the South Pacific Gyre, ISME J., 6, 1238–1249, 2012.
Hoppe, H. G., Gocke, K., Koppe, R., and Begler, C.: Bacterial growth and
primary production along a north-south transect of the Atlantic Ocean,
Nature, 416, 168–171, 2002.
Jiao, N., Herndl, G. J., Hansell, D. A., Benner, R., Kattner, G. K., Wilhelm,
S. W., Kirchman, D. L., Weinbauer, M. G., Luo, T., Chen, F., and Azam, F.:
Microbial production of recalcitrant dissolved organic matter: long-term
carbon storage in the global ocean, Nat. Rev. Microbiol., 8, 593–599, 2010.
Kirchman, D. L.: Leucine incorporation as a measure of biomass production by
heterotrophic bacteria, in: Handbook of methods in aquatic microbial
ecology, edited by: Kemp, P. F., Sherr, B. F., Sherr, E. B., and Cole, J.
J., Boca Raton, Lewis, 509–512, 1993.
Keil, R. G. and Kirchman, D. L.: Abiotic transformation of labile protein to
refractory protein in sea water, Mar. Chem., 45, 187–196, 1994.
Le Bouteiller, A., Blanchot, J., and Rodier, M.: Size distribution patterns
of phytoplankton in the western tropical Pacific: towards a generalization
for the tropical ocean, Deep-Sea Res. 39, 803–823, 1992.
Lemée, R., Rochelle-Newall, E., Van Wambeke, F., Pizay, M.-D., Rinaldi,
P., and Gattuso, J.-P.: Seasonal variation of bacterial production,
respiration and growth efficiency in the open NW Mediterranean Sea, Aquat.
Microb. Ecol., 29, 227–237, 2002.
Letscher, R. T. and Moore, J. K.: Modest net autotrophy in the oligotrophic
ocean, Global Biogeochem. Cy., 31, 699–708, 2017.
Letscher, R. T., Knapp, A. N., James, A. K., Carlson, C. A., Santoro, A. E.,
and Hansell, D. A.: Microbial community composition and nitrogen availability
influence DOC remineralization in the South Pacific Gyre, Mar. Chem., 177,
325–334, 2015.
Luo, Y.-W., Lima, I. D., Karl, D. M., Deutsch, C. A., and Doney, S. C.:
Data-based assessment of environmental controls on global marine nitrogen
fixation, Biogeosciences, 11, 691–708,
https://doi.org/10.5194/bg-11-691-2014, 2014.
Martínez-Pérez, C., Mohr, W., Löscher, C. R., Dekaezemacker, J.,
Littmann, S., Yilmaz, P., Lehnen, N., Fuchs, B. M., Lavik, G., Schmitz, R.
A., LaRoche, J., and Kuypers, M. M.: The small unicellular diazotrophic
symbiont, UCYN-A, is a key player in the marine nitrogen cycle, Nat.
Microbiol., 1, 16163, https://doi.org/10.1038/nmicrobiol.2016.163., 2016.
Martino, M., Hamilton, D., Baker, A. R., Jickells, T. D., Bromley, T.,
Nojiri, Y., Quack, B., and Boyd, P. W.: Western Pacific atmospheric nutrient
deposition fluxes, their impact on surface ocean productivity, Global
Biogeochem. Cy., 28, 712–728, 2014.
Menkes, C. E., Allain, V., Rodier, M., Gallois, F., Lebourges-Dhaussy, A.,
Hunt, B. P. V., Smeti, H., Pagano, M., Josse, E., Daroux, A., Lehodey, P.,
Senina, I., Kestenare, E., Lorrain, A., and Nicol, S.: Seasonal oceanography
from physics to micronekton in the south-west Pacific, Deep-Sea Res. Pt. II,
113, 125–144, 2015.
Messer, L. F., Brown, M. V., Furnas, M. J., Carney, R. L., McKinnon, A. D.,
and Seymour, J. R.: Diversity and Activity of Diazotrophs in Great Barrier
Reef Surface Waters, Front. Microbiol., 8, 967,
https://doi.org/10.3389/fmicb.2017.00967, 2017.
Moisander, P. H., Serros, T., Paerl, R. W., Beinart, R. A., and Zehr, J. P.:
Gammaproteobacterial diazotrophs and nifH gene expression in surface waters
of the South Pacific Ocean, ISME J., 8, 1962–1973,
https://doi.org/10.1038/ismej.2014.49, 2014.
Moutin, T., Raimbault, P., and Poggiale, J. C.: Production primaire dans les
eaux de surface de la Méditerranée occidentale: Calcul de la
production journalière, C. R. Acad. Sci. Paris, 322, 651–659, 1999.
Moutin, T., Van Den Broeck, N., Beker, B., Dupouy, C., Rimmelin, P., and Le
Bouteiller, A.: Phosphate availability controls Trichodesmium spp. biomass in
the SW Pacific ocean, Mar. Ecol. Prog. Ser., 297, 15–21, 2005.
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.
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,
doi.org/10.5194/bg-14-3207-2017, 2017.
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 Discuss., https://doi.org/10.5194/bg-2017-565, in
press, 2018.
Neveux, J., Lefebvre, J. P., Le Gendre, R., Dupouy, C., Gallois, F.,
Courties, C., Gérard, P., Fernandez, J. M., and Ouillon, S.:
Phytoplankton dynamics in the southern New Caledonian lagoon during a
southeast trade winds event, J. Mar. Syst., 82, 230–244, 2010.
Pringault, O., Tassas, V., and Rochelle-Newall, E.: Consequences of
respiration in the light on the determination of production in pelagic
systems, Biogeosciences, 4, 105–114, https://doi.org/10.5194/bg-4-105-2007,
2007.
Rahav, E., Bar-Zeev, E., Ohayon, S., Elifantz, H., Belkin, N., Herut, B.,
Mulholland, M. R., and Ilana Berman-Frank, I.: Dinitrogen fixation in aphotic
oxygenated marine environments, Front. Microbiol., 4, 227,
https://doi.org/10.3389/fmicb.2013.00227, 2013.
Raimbault, P. and Garcia, N.: Evidence for efficient regenerated production
and dinitrogen fixation in nitrogen-deficient waters of the South Pacific
Ocean: impact on new and export production estimates, Biogeosciences, 5,
323–338, https://doi.org/10.5194/bg-5-323-2008, 2008.
Raimbault, P., Garcia, N., and Cerutti, F.: Distribution of inorganic and
organic nutrients in the South Pacific Ocean – evidence for long-term
accumulation of organic matter in nitrogen-depleted waters, Biogeosciences,
5, 281–298, https://doi.org/10.5194/bg-5-281-2008, 2008.
Rii, Y. M., Duhamel, S., Bidigare, R. R., Karl, D. M., Repeta, D. J., and
Church, M. J.: Diversity and productivity of photosynthetic picoeukaryotes in
biogeochemically distinct regions of the South East Pacific Ocean, Limnol.
Oceanogr., 61, 806–824, 2016.
Rivkin, R. B. and Legendre, L.: Biogenic carbon cycling in the upper ocean:
effects of microbial respiration, Science, 291, 2398–2400, 2001.
Rousselet, L., de Verneil, A., Doglioli, A. M., Petrenko, A. A., Duhamel, S.,
Maes, C., and Blanke, B.: Large to submesoscale surface circulation and its
implications on biogeochemical/biological horizontal distributions during the
OUTPACE cruise (SouthWest Pacific), Biogeosciences,
15, 2411–2431, https://doi.org/10.5194/bg-15-2411-2018, 2018
Ruiz-González, C., Simó, R., Sommaruga, R., and Gasol, J. M.: Away
from darkness: a review on the effects of solar radiation on heterotrophic
bacterioplankton activity, Front. Microbiol., 4, 13,
https://doi.org/10.3389/fmicb.2013.00131, 2013.
Serret, P., Robinson, C., Aranguren-Gassis, M., García-Martín, E.
E. N. G., Kitidis, V., Lozano, J., Stephens, J., Harris, C., and Thomas, R.:
Both respiration and photosynthesis determine the scaling of plankton
metabolism in the oligotrophic ocean, Nat. Commun., 6, 6961,
https://doi.org/10.1038/ncomms7961, 2015.
Shiozaki, T., Kodama, T., and Furuya, K.: Large-scale impact of the island
mass effect through nitrogen fixation in the western South Pacific Ocean,
Geophys. Res. Lett., 41, 2907–2913, 2014.
Smith, D. C. and Azam, F.: A simple, economical method for measuring
bacterial protein synthesis rates in sea water using 3H-Leucine, Mar.
Microb. Food Webs, 6, 107–114, 1992.
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, doi.org/10.5194/bg-15-1559-2018, 2018.
Tenório, M. M., Dupouy, C., Rodier, M., and Neveux, J.: Trichodesmium and
other planktonic cyanobacteria in New Caledonian waters (South West Tropical
Pacific) during an El Niño Episode, Aquatic Microbial Ecology, in press,
https://doi.org/10.3354/ame01873, 2018
Tranvik, L. and Kokalj, S.: Biodegradability of algal DOC due to interactive
effects of UV radiation and humic matter, Aquat. Microb. Ecol., 14, 301–307,
1998.
Turk-Kubo, K. A., Karamchandani, M., Capone, D. G., and Zehr, J. P.: The
paradox of marine heterotrophic nitrogen fixation: abundances of
heterotrophic diazotrophs do not account for nitrogen fixation rates in the
Eastern Tropical South Pacific, Environ. Microbiol., 16, 3095–3114, 2014.
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.
Van Wambeke, F., Bonnet, S., Moutin, T., Raimbault, P., Alarcón, G., and
Guieu, C.: Factors limiting heterotrophic bacterial production in the
southern Pacific Ocean, Biogeosciences, 5, 833–845,
https://doi.org/10.5194/bg-5-833-2008, 2008a.
Van Wambeke, F., Obernosterer, I., Moutin, T., Duhamel, S., Ulloa, O., and
Claustre, H.: Heterotrophic bacterial production in the eastern South
Pacific: longitudinal trends and coupling with primary production,
Biogeosciences, 5, 157–169, https://doi.org/10.5194/bg-5-157-2008, 2008b.
Williams, P. J. L. B. and Jenkinson, N. W.: A transportable
microprocessor-controlled precise Winkler titration suitable for field
station and shipboard use, Limnol. Oceanogr., 27, 576–584, 1982.
Williams, P. J. L. B., Quay, P. D., Westberry, T. K., and Behrenfeld, M. J.:
The Oligotrophic Ocean Is Autotrophic, Annu. Rev. Mar. Sci., 5, 535–549,
2013.
Wilson, S. T., Aylward, F. O., Ribalet, F., Barone, B., Casey, J. R.,
Connell, P. E., Eppley, J. M., Ferrón, S., Fitzsimmons, J. N., Hayes, C.
T., Romano, A. E., Turk-Kubo, K. A., Vislova, A., Armbrust, E. V., Caron, D.
A., Church, M. J., Zehr, J. P., Karl, D. M., and DeLong, E. F.: Coordinated
regulation of growth, activity and transcription in natural populations of
the unicellular nitrogen-fixing cyanobacterium Crocosphaera, Nat.
Microbiol., 2, 17118, https://doi.org/10.1038/nmicrobiol.2017.118, 2017.
Yang, B., Emerson, S. R., and Bushinsky, S. M.: Annual net community
production in the subtropical Pacific Ocean from in situ oxygen measurements
on profiling floats, Global Biogeochem. Cy., https://doi.org/10.1002/2016GB005545,
2017.
Yang, B., Emerson, S. R., and Bushinsky, S. M.: Annual net community
production in the subtropical Pacific Ocean from in situ oxygen measurements
on profiling floats, Global Biogeochem. Cy., https://doi.org/10.1002/2016GB005545,
2017.
Young, J. W., Hobday, A. J., Campbell, R. A., Kloser, R. J., Bonham, P. I.,
Clementson, L. A., and Lansdell, M. J.: The biological oceanography of the
East Australian Current and surrounding waters in relation to tuna and
billfish catches off eastern Australia, Deep-Sea Res. Pt. II, 58, 720–733,
2011.
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).
The western tropical South Pacific Ocean has recently been shown to be a hotspot for biological...
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