1
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Wang WL, Fu W, Le Moigne FAC, Letscher RT, Liu Y, Tang JM, Primeau FW. Biological carbon pump estimate based on multidecadal hydrographic data. Nature 2023; 624:579-585. [PMID: 38057667 PMCID: PMC10733149 DOI: 10.1038/s41586-023-06772-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 10/20/2023] [Indexed: 12/08/2023]
Abstract
The transfer of photosynthetically produced organic carbon from surface to mesopelagic waters draws carbon dioxide from the atmosphere1. However, current observation-based estimates disagree on the strength of this biological carbon pump (BCP)2. Earth system models (ESMs) also exhibit a large spread of BCP estimates, indicating limited representations of the known carbon export pathways3. Here we use several decades of hydrographic observations to produce a top-down estimate of the strength of the BCP with an inverse biogeochemical model that implicitly accounts for all known export pathways. Our estimate of total organic carbon (TOC) export at 73.4 m (model euphotic zone depth) is 15.00 ± 1.12 Pg C year-1, with only two-thirds reaching 100 m depth owing to rapid remineralization of organic matter in the upper water column. Partitioned by sequestration time below the euphotic zone, τ, the globally integrated organic carbon production rate with τ > 3 months is 11.09 ± 1.02 Pg C year-1, dropping to 8.25 ± 0.30 Pg C year-1 for τ > 1 year, with 81% contributed by the non-advective-diffusive vertical flux owing to sinking particles and vertically migrating zooplankton. Nevertheless, export of organic carbon by mixing and other fluid transport of dissolved matter and suspended particles remains regionally important for meeting the respiratory carbon demand. Furthermore, the temperature dependence of the sequestration efficiency inferred from our inversion suggests that future global warming may intensify the recycling of organic matter in the upper ocean, potentially weakening the BCP.
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Affiliation(s)
- Wei-Lei Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
| | - Weiwei Fu
- Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
- Department of Atmospheric and Oceanic Science, Fudan University, Shanghai, China
| | | | - Robert T Letscher
- Earth Sciences and Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH, USA
| | - Yi Liu
- Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Jin-Ming Tang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - François W Primeau
- Department of Earth System Science, University of California, Irvine, Irvine, CA, USA.
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2
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Bonnet S, Guieu C, Taillandier V, Boulart C, Bouruet-Aubertot P, Gazeau F, Scalabrin C, Bressac M, Knapp AN, Cuypers Y, González-Santana D, Forrer HJ, Grisoni JM, Grosso O, Habasque J, Jardin-Camps M, Leblond N, Le Moigne FAC, Lebourges-Dhaussy A, Lory C, Nunige S, Pulido-Villena E, Rizzo AL, Sarthou G, Tilliette C. Natural iron fertilization by shallow hydrothermal sources fuels diazotroph blooms in the ocean. Science 2023; 380:812-817. [PMID: 37228198 DOI: 10.1126/science.abq4654] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 04/21/2023] [Indexed: 05/27/2023]
Abstract
Iron is an essential nutrient that regulates productivity in ~30% of the ocean. Compared with deep (>2000 meter) hydrothermal activity at mid-ocean ridges that provide iron to the ocean's interior, shallow (<500 meter) hydrothermal fluids are likely to influence the surface's ecosystem. However, their effect is unknown. In this work, we show that fluids emitted along the Tonga volcanic arc (South Pacific) have a substantial impact on iron concentrations in the photic layer through vertical diffusion. This enrichment stimulates biological activity, resulting in an extensive patch of chlorophyll (360,000 square kilometers). Diazotroph activity is two to eight times higher and carbon export fluxes are two to three times higher in iron-enriched waters than in adjacent unfertilized waters. Such findings reveal a previously undescribed mechanism of natural iron fertilization in the ocean that fuels regional hotspot sinks for atmospheric CO2.
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Affiliation(s)
- Sophie Bonnet
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
| | - Cécile Guieu
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Vincent Taillandier
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Cédric Boulart
- Adaptation et Diversité en Milieu Marin, UMR 7144 AD2M CNRS-Sorbonne Université, Station Biologique de Roscoff, 29680 Roscoff, France
| | - Pascale Bouruet-Aubertot
- Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques (LOCEAN-IPSL), Sorbonne University, CNRS-IRD-MNHN, 75005 Paris, France
| | - Frédéric Gazeau
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Carla Scalabrin
- Ifremer, Univ Brest, CNRS, UMR 6538 Geo-Ocean, F-29280 Plouzané, France
| | - Matthieu Bressac
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
| | - Angela N Knapp
- Department of Earth, Ocean, and Atmospheric Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Yannis Cuypers
- Laboratoire d'Océanographie et du Climat: Expérimentation et Approches Numériques (LOCEAN-IPSL), Sorbonne University, CNRS-IRD-MNHN, 75005 Paris, France
| | - David González-Santana
- CNRS, Univ Brest, IRD, Ifremer, UMR 6539, LEMAR, Plouzané, France
- Instituto de Oceanografía y Cambio Global (IOCAG), Universidad de Las Palmas de Gran Canaria, 35017 Las Palmas, Spain
| | - Heather J Forrer
- Department of Earth, Ocean, and Atmospheric Sciences, Florida State University, Tallahassee, FL 32306, USA
| | - Jean-Michel Grisoni
- Institut de la Mer de Villefranche, IMEV, Sorbonne Université, Villefranche-sur-Mer, France
| | - Olivier Grosso
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
| | - Jérémie Habasque
- CNRS, Univ Brest, IRD, Ifremer, UMR 6539, LEMAR, Plouzané, France
| | | | - Nathalie Leblond
- Institut de la Mer de Villefranche, IMEV, Sorbonne Université, Villefranche-sur-Mer, France
| | - Frédéric A C Le Moigne
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
- CNRS, Univ Brest, IRD, Ifremer, UMR 6539, LEMAR, Plouzané, France
| | | | - Caroline Lory
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
| | - Sandra Nunige
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO Marseille, France
| | | | - Andrea L Rizzo
- Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Milano, Via Alfonso Corti 12, 20133 Milano, Italy
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 4, 20126 Milan, Italy
| | | | - Chloé Tilliette
- Laboratoire d'Océanographie de Villefranche (LOV), Institut de la Mer de Villefranche, CNRS, Sorbonne Université, 06230 Villefranche-sur-Mer, France
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3
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Bonnet S, Benavides M, Le Moigne FAC, Camps M, Torremocha A, Grosso O, Dimier C, Spungin D, Berman-Frank I, Garczarek L, Cornejo-Castillo FM. Diazotrophs are overlooked contributors to carbon and nitrogen export to the deep ocean. ISME J 2023; 17:47-58. [PMID: 36163270 PMCID: PMC9750961 DOI: 10.1038/s41396-022-01319-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/25/2022] [Accepted: 09/06/2022] [Indexed: 11/09/2022]
Abstract
Diazotrophs are widespread microorganisms that alleviate nitrogen limitation in 60% of our oceans, thereby regulating marine productivity. Yet, the group-specific contribution of diazotrophs to organic matter export has not been quantified, which so far has impeded an accurate assessment of their impact on the biological carbon pump. Here, we examine the fate of five groups of globally-distributed diazotrophs by using an original combination of mesopelagic particle sampling devices across the subtropical South Pacific Ocean. We demonstrate that cyanobacterial and non-cyanobacterial diazotrophs are exported down to 1000 m depth. Surprisingly, group-specific export turnover rates point to a more efficient export of small unicellular cyanobacterial diazotrophs (UCYN) relative to the larger and filamentous Trichodesmium. Phycoerythrin-containing UCYN-B and UCYN-C-like cells were recurrently found embedded in large (>50 µm) organic aggregates or organized into clusters of tens to hundreds of cells linked by an extracellular matrix, presumably facilitating their export. Beyond the South Pacific, our data are supported by analysis of the Tara Oceans metagenomes collected in other ocean basins, extending the scope of our results globally. We show that, when diazotrophs are found in the euphotic zone, they are also systematically present in mesopelagic waters, suggesting their transport to the deep ocean. We thus conclude that diazotrophs are a significant part of the carbon sequestered in the deep ocean and, therefore, they need to be accounted in regional and global estimates of export.
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Affiliation(s)
- Sophie Bonnet
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France.
| | - Mar Benavides
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France ,grid.5399.60000 0001 2176 4817Turing Center for Living Systems, Aix-Marseille University, 13009 Marseille, France
| | - Frédéric A. C. Le Moigne
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France ,grid.463763.30000 0004 0638 0577LEMAR, Laboratoire des sciences de l’environnement marin, UMR6539, CNRS, UBO, IFREMER, IRD, 29280 Plouzané, Technopôle Brest-Iroise France
| | - Mercedes Camps
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Antoine Torremocha
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Olivier Grosso
- Aix Marseille University, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Céline Dimier
- grid.499565.20000 0004 0366 8890Laboratoire d’Océanographie de Villefranche (LOV), Sorbonne Université, CNRS, 06230 Villefranche sur mer, France
| | - Dina Spungin
- grid.18098.380000 0004 1937 0562University of Haifa, The Leon H. Charney School of Marine Sciences, Haifa, 3498838 Israel
| | - Ilana Berman-Frank
- grid.18098.380000 0004 1937 0562University of Haifa, The Leon H. Charney School of Marine Sciences, Haifa, 3498838 Israel
| | - Laurence Garczarek
- grid.464101.60000 0001 2203 0006Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Francisco M. Cornejo-Castillo
- grid.464101.60000 0001 2203 0006Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France ,grid.418218.60000 0004 1793 765XInstitut de Ciènces del Mar (ICM-CSIC), E08003 Barcelona, Spain
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4
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Benavides M, Bonnet S, Le Moigne FAC, Armin G, Inomura K, Hallstrøm S, Riemann L, Berman-Frank I, Poletti E, Garel M, Grosso O, Leblanc K, Guigue C, Tedetti M, Dupouy C. Sinking Trichodesmium fixes nitrogen in the dark ocean. ISME J 2022; 16:2398-2405. [PMID: 35835942 PMCID: PMC9478103 DOI: 10.1038/s41396-022-01289-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/29/2022] [Accepted: 07/05/2022] [Indexed: 01/04/2023]
Abstract
The photosynthetic cyanobacterium Trichodesmium is widely distributed in the surface low latitude ocean where it contributes significantly to N2 fixation and primary productivity. Previous studies found nifH genes and intact Trichodesmium colonies in the sunlight-deprived meso- and bathypelagic layers of the ocean (200-4000 m depth). Yet, the ability of Trichodesmium to fix N2 in the dark ocean has not been explored. We performed 15N2 incubations in sediment traps at 170, 270 and 1000 m at two locations in the South Pacific. Sinking Trichodesmium colonies fixed N2 at similar rates than previously observed in the surface ocean (36-214 fmol N cell-1 d-1). This activity accounted for 40 ± 28% of the bulk N2 fixation rates measured in the traps, indicating that other diazotrophs were also active in the mesopelagic zone. Accordingly, cDNA nifH amplicon sequencing revealed that while Trichodesmium accounted for most of the expressed nifH genes in the traps, other diazotrophs such as Chlorobium and Deltaproteobacteria were also active. Laboratory experiments simulating mesopelagic conditions confirmed that increasing hydrostatic pressure and decreasing temperature reduced but did not completely inhibit N2 fixation in Trichodesmium. Finally, using a cell metabolism model we predict that Trichodesmium uses photosynthesis-derived stored carbon to sustain N2 fixation while sinking into the mesopelagic. We conclude that sinking Trichodesmium provides ammonium, dissolved organic matter and biomass to mesopelagic prokaryotes.
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Affiliation(s)
- Mar Benavides
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France.
- Turing Center for Living Systems, Aix-Marseille University, 13009, Marseille, France.
| | - Sophie Bonnet
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Frédéric A C Le Moigne
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
- LEMAR, Laboratoire des Sciences de l'Environnement Marin, UMR6539, CNRS, UBO, IFREMER, IRD, 29280, Plouzané, Technopôle Brest-Iroise, France
| | - Gabrielle Armin
- Graduate School of Oceanography, University of Rhode Island, South Kingstown, RI, USA
| | - Keisuke Inomura
- Graduate School of Oceanography, University of Rhode Island, South Kingstown, RI, USA
| | - Søren Hallstrøm
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Lasse Riemann
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Ilana Berman-Frank
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, Mt, Carmel, Haifa, Israel
| | - Emilie Poletti
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Marc Garel
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Olivier Grosso
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Karine Leblanc
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Catherine Guigue
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Marc Tedetti
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Cécile Dupouy
- Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
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5
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Baumas CMJ, Le Moigne FAC, Garel M, Bhairy N, Guasco S, Riou V, Armougom F, Grossart HP, Tamburini C. Mesopelagic microbial carbon production correlates with diversity across different marine particle fractions. ISME J 2021; 15:1695-1708. [PMID: 33452475 PMCID: PMC8163737 DOI: 10.1038/s41396-020-00880-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 12/02/2020] [Accepted: 12/09/2020] [Indexed: 01/29/2023]
Abstract
The vertical flux of marine snow particles significantly reduces atmospheric carbon dioxide concentration. In the mesopelagic zone, a large proportion of the organic carbon carried by sinking particles dissipates thereby escaping long term sequestration. Particle associated prokaryotes are largely responsible for such organic carbon loss. However, links between this important ecosystem flux and ecological processes such as community development of prokaryotes on different particle fractions (sinking vs. non-sinking) are yet virtually unknown. This prevents accurate predictions of mesopelagic organic carbon loss in response to changing ocean dynamics. Using combined measurements of prokaryotic heterotrophic production rates and species richness in the North Atlantic, we reveal that carbon loss rates and associated microbial richness are drastically different with particle fractions. Our results demonstrate a strong negative correlation between prokaryotic carbon losses and species richness. Such a trend may be related to prokaryotes detaching from fast-sinking particles constantly enriching non-sinking associated communities in the mesopelagic zone. Existing global scale data suggest this negative correlation is a widespread feature of mesopelagic microbes.
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Affiliation(s)
- Chloé M. J. Baumas
- grid.500499.10000 0004 1758 6271Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France
| | - Frédéric A. C. Le Moigne
- grid.500499.10000 0004 1758 6271Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France
| | - Marc Garel
- grid.500499.10000 0004 1758 6271Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France
| | - Nagib Bhairy
- grid.500499.10000 0004 1758 6271Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France
| | - Sophie Guasco
- grid.500499.10000 0004 1758 6271Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France
| | - Virginie Riou
- grid.500499.10000 0004 1758 6271Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France
| | - Fabrice Armougom
- grid.500499.10000 0004 1758 6271Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France
| | - Hans-Peter Grossart
- grid.419247.d0000 0001 2108 8097Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Stechlin, Germany ,grid.11348.3f0000 0001 0942 1117Institute of Biochemistry and Biology, Postdam University, 14469 Potsdam, Germany
| | - Christian Tamburini
- grid.500499.10000 0004 1758 6271Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO, UM 110), Marseille, France
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6
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Hopwood MJ, Carroll D, Höfer J, Achterberg EP, Meire L, Le Moigne FAC, Bach LT, Eich C, Sutherland DA, González HE. Highly variable iron content modulates iceberg-ocean fertilisation and potential carbon export. Nat Commun 2019; 10:5261. [PMID: 31748607 PMCID: PMC6868171 DOI: 10.1038/s41467-019-13231-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 10/29/2019] [Indexed: 11/17/2022] Open
Abstract
Marine phytoplankton growth at high latitudes is extensively limited by iron availability. Icebergs are a vector transporting the bioessential micronutrient iron into polar oceans. Therefore, increasing iceberg fluxes due to global warming have the potential to increase marine productivity and carbon export, creating a negative climate feedback. However, the magnitude of the iceberg iron flux, the subsequent fertilization effect and the resultant carbon export have not been quantified. Using a global analysis of iceberg samples, we reveal that iceberg iron concentrations vary over 6 orders of magnitude. Our results demonstrate that, whilst icebergs are the largest source of iron to the polar oceans, the heterogeneous iron distribution within ice moderates iron delivery to offshore waters and likely also affects the subsequent ocean iron enrichment. Future marine productivity may therefore be not only sensitive to increasing total iceberg fluxes, but also to changing iceberg properties, internal sediment distribution and melt dynamics.
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Affiliation(s)
- Mark J Hopwood
- GEOMAR, Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
| | - Dustin Carroll
- Moss Landing Marine Laboratories, San José State University, Moss Landing, CA, USA
| | - Juan Höfer
- Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
- Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
| | | | - Lorenz Meire
- Royal Netherlands Institute for Sea Research, and Utrecht University, Yerseke, The Netherlands
- Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland
| | - Frédéric A C Le Moigne
- Mediterranean Institute of Oceanography, UM110, CNRS, IRD, Aix Marseille Université Marseille, Marseille, France
| | - Lennart T Bach
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Charlotte Eich
- Royal Netherlands Institute for Sea Research, and University of Amsterdam, Texel, The Netherlands
| | | | - Humberto E González
- Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
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7
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Le Moigne FAC, Pabortsava K, Marcinko CLJ, Martin P, Sanders RJ. Where is mineral ballast important for surface export of particulate organic carbon in the ocean? Geophys Res Lett 2014; 41:8460-8468. [PMID: 26074644 PMCID: PMC4459180 DOI: 10.1002/2014gl061678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 10/22/2014] [Indexed: 05/26/2023]
Abstract
Correlations between particulate organic carbon (POC) and mineral fluxes in the deep ocean have inspired the inclusion of "ballast effect" parameterizations in carbon cycle models. A recent study demonstrated regional variability in the effect of ballast minerals on the flux of POC in the deep ocean. We have undertaken a similar analysis of shallow export data from the Arctic, Atlantic, and Southern Oceans. Mineral ballasting is of greatest importance in the high-latitude North Atlantic, where 60% of the POC flux is associated with ballast minerals. This fraction drops to around 40% in the Southern Ocean. The remainder of the export flux is not associated with minerals, and this unballasted fraction thus often dominates the export flux. The proportion of mineral-associated POC flux often scales with regional variation in export efficiency (the proportion of primary production that is exported). However, local discrepancies suggest that regional differences in ecology also impact the magnitude of surface export. We propose that POC export will not respond equally across all high-latitude regions to possible future changes in ballast availability.
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Affiliation(s)
| | | | | | - Patrick Martin
- School of Ocean and Earth Science, University of SouthamptonSouthampton, UK
- Earth Observatory of Singapore, Nanyang Technological UniversitySingapore
| | - Richard J Sanders
- Ocean Biogeochemistry and Ecosystems, National Oceanography CentreSouthampton, UK
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