1
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Arnone V, Santana-Casiano JM, González-Dávila M, Sarthou G, Krisch S, Lodeiro P, Achterberg EP, González AG. Distribution of copper-binding ligands in Fram Strait and influences from the Greenland Shelf (GEOTRACES GN05). Sci Total Environ 2024; 909:168162. [PMID: 37952666 DOI: 10.1016/j.scitotenv.2023.168162] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 09/11/2023] [Accepted: 10/25/2023] [Indexed: 11/14/2023]
Abstract
The Fram Strait represents the major gateway of Arctic Ocean waters towards the Nordic Seas and North Atlantic Ocean and is a key region to study the impact of climate change on biogeochemical cycles. In the region, information about trace metal speciation, such as copper, is scarce. This manuscript presents the concentrations and conditional stability constants of copper-binding ligands (LCu and log KcondCu2+L) in the water column of Fram Strait and the Greenland shelf (GEOTRACES cruise GN05). Cu-binding ligands were analysed by Competitive Ligand Exchange-Adsorptive Cathodic Stripping Voltammetry (CLE-ACSV) using salicylaldoxime (SA) as competitive ligand. Based on water masses and the hydrodynamic influences, three provinces were considered (coast, shelf, and Fram Strait) and differences were observed between regions and water masses. The strongest variability was observed in surface waters, with increasing LCu concentrations (mean values: Fram Strait = 2.6 ± 1.0 nM; shelf = 5.2 ± 1.3 nM; coast = 6.4 ± 0.8 nM) and decreasing log KcondCu2+L values (mean values: Fram Strait = 15.7 ± 0.3; shelf = 15.2 ± 0.3; coast = 14.8 ± 0.3) towards the west. The surface LCu concentrations obtained above the Greenland shelf indicate a supply from the coastal environment to the Polar Surface Water (PSW) which is an addition to the ligand exported from the central Arctic to Fram Strait. The significant differences (in terms of LCu and log KcondCu2+L) between shelf and coastal samples were explained considering the processes which modify ligand concentrations and binding strengths, such as biological activity in sea-ice, phytoplankton bloom in surface waters, bacterial degradation, and meltwater discharge from 79NG glacier terminus. Overall, the ligand concentration exceeded those of dissolved Cu (dCu) and kept the free copper (Cu2+) concentrations at femtomolar levels (0.13-21.13 fM). This indicates that Cu2+ toxicity limits were not reached and dCu levels were stabilized in surface waters by organic complexes, which favoured its transport to the Nordic Seas and North Atlantic Ocean and the development of microorganism.
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Affiliation(s)
- Veronica Arnone
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, ULPGC, Spain
| | | | - Melchor González-Dávila
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, ULPGC, Spain
| | | | - Stephan Krisch
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Germany
| | - Pablo Lodeiro
- Department of Chemistry, Physics, Environmental and Soil sciences, University of Lleida-AGROTECNIO-CERCA Center, Rovira Roure 191, 25198, Lleida, Spain
| | - Eric P Achterberg
- GEOMAR Helmholtz Centre for Ocean Research Kiel, 24148 Kiel, Germany
| | - Aridane G González
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, ULPGC, Spain.
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2
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Hansen KE, Pearce C, Seidenkrantz MS. Response of Arctic benthic foraminiferal traits to past environmental changes. Sci Rep 2023; 13:22135. [PMID: 38092797 PMCID: PMC10719382 DOI: 10.1038/s41598-023-47603-w] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/16/2023] [Indexed: 12/17/2023] Open
Abstract
The Arctic is subjected to all-encompassing disruptions in marine ecosystems caused by anthropogenic warming. To provide reliable estimates of how future changes will affect the ecosystems, knowledge of Arctic marine ecosystem responses to past environmental variability beyond the instrumental era is essential. Here, we present a novel approach on how to evaluate the state of benthic marine biotic conditions during the deglacial and Holocene period on the Northeast Greenland shelf. Benthic foraminiferal species were assigned traits (e.g., oxygen tolerance, food preferences) aiming to identify past faunal changes as a response to external forcing mechanisms. This approach was applied on sediment cores from offshore Northeast Greenland. We performed numerical rate-of-change detection to determine significant changes in the benthic foraminiferal traits. That way, the significant abrupt trait changes can be assessed across sites, providing a better understanding of the impact of climate drivers on the traits. Our results demonstrate that during the last ~ 14,000 years, bottom water oxygen is the main factor affecting the variability in the benthic foraminiferal faunas in this area. Our results show that significant changes in the traits correspond to drastic climate perturbations. Specifically, the deglacial-Holocene transition and mid-Holocene warm period exhibited significant change, with several trait turnovers.
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Affiliation(s)
- Katrine Elnegaard Hansen
- Paleoceanography and Paleoclimate Group, Department of Geoscience, Arctic Research Center and iClimate Center, Aarhus University, Aarhus, Denmark.
- Department of Near Surface Land and Marine Geology, The Geological Survey of Denmark and Greenland (GEUS), Aarhus, Denmark.
| | - Christof Pearce
- Paleoceanography and Paleoclimate Group, Department of Geoscience, Arctic Research Center and iClimate Center, Aarhus University, Aarhus, Denmark
| | - Marit-Solveig Seidenkrantz
- Paleoceanography and Paleoclimate Group, Department of Geoscience, Arctic Research Center and iClimate Center, Aarhus University, Aarhus, Denmark
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Westbury MV, Brown SC, Lorenzen J, O’Neill S, Scott MB, McCuaig J, Cheung C, Armstrong E, Valdes PJ, Samaniego Castruita JA, Cabrera AA, Blom SK, Dietz R, Sonne C, Louis M, Galatius A, Fordham DA, Ribeiro S, Szpak P, Lorenzen ED. Impact of Holocene environmental change on the evolutionary ecology of an Arctic top predator. Sci Adv 2023; 9:eadf3326. [PMID: 37939193 PMCID: PMC10631739 DOI: 10.1126/sciadv.adf3326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 06/09/2023] [Accepted: 10/06/2023] [Indexed: 11/10/2023]
Abstract
The Arctic is among the most climatically sensitive environments on Earth, and the disappearance of multiyear sea ice in the Arctic Ocean is predicted within decades. As apex predators, polar bears are sentinel species for addressing the impact of environmental variability on Arctic marine ecosystems. By integrating genomics, isotopic analysis, morphometrics, and ecological modeling, we investigate how Holocene environmental changes affected polar bears around Greenland. We uncover reductions in effective population size coinciding with increases in annual mean sea surface temperature, reduction in sea ice cover, declines in suitable habitat, and shifts in suitable habitat northward. Furthermore, we show that west and east Greenlandic polar bears are morphologically, and ecologically distinct, putatively driven by regional biotic and genetic differences. Together, we provide insights into the vulnerability of polar bears to environmental change and how the Arctic marine ecosystem plays a vital role in shaping the evolutionary and ecological trajectories of its inhabitants.
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Affiliation(s)
- Michael V. Westbury
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stuart C. Brown
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
- Department for Environment and Water, Adelaide, South Australia, Australia
| | - Julie Lorenzen
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stuart O’Neill
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Michael B. Scott
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Julia McCuaig
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Christina Cheung
- Department of Anthropology, Chinese University of Hong Kong, Shatin, Hong Kong
| | - Edward Armstrong
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
| | - Paul J. Valdes
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | | | - Andrea A. Cabrera
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Stine Keibel Blom
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
| | - Rune Dietz
- Arctic Research Centre (ARC), Department of Ecoscience, Aarhus University, Frederiksborgvej 399, PO Box 358, Roskilde DK-4000, Denmark
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Christian Sonne
- Arctic Research Centre (ARC), Department of Ecoscience, Aarhus University, Frederiksborgvej 399, PO Box 358, Roskilde DK-4000, Denmark
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Marie Louis
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Greenland Institute of Natural Resources, Kivioq 2, PO Box 570, Nuuk 3900, Denmark
| | - Anders Galatius
- Section for Marine Mammal Research, Department of Ecoscience, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Damien A. Fordham
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Sofia Ribeiro
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
- Glaciology and Climate Department, Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, Copenhagen DK-1350, Denmark
| | - Paul Szpak
- Department of Anthropology, Trent University, 1600 West Bank Drive, Peterborough, Ontario K9L0G2, Canada
| | - Eline D. Lorenzen
- Globe Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen DK-1350, Denmark
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Zhang T, Li D, East AE, Kettner AJ, Best J, Ni J, Lu X. Shifted sediment-transport regimes by climate change and amplified hydrological variability in cryosphere-fed rivers. Sci Adv 2023; 9:eadi5019. [PMID: 37939190 PMCID: PMC10631733 DOI: 10.1126/sciadv.adi5019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 10/05/2023] [Indexed: 11/10/2023]
Abstract
Climate change affects cryosphere-fed rivers and alters seasonal sediment dynamics, affecting cyclical fluvial material supply and year-round water-food-energy provisions to downstream communities. Here, we demonstrate seasonal sediment-transport regime shifts from the 1960s to 2000s in four cryosphere-fed rivers characterized by glacial, nival, pluvial, and mixed regimes, respectively. Spring sees a shift toward pluvial-dominated sediment transport due to less snowmelt and more erosive rainfall. Summer is characterized by intensified glacier meltwater pulses and pluvial events that exceptionally increase sediment fluxes. Our study highlights that the increases in hydroclimatic extremes and cryosphere degradation lead to amplified variability in fluvial fluxes and higher summer sediment peaks, which can threaten downstream river infrastructure safety and ecosystems and worsen glacial/pluvial floods. We further offer a monthly-scale sediment-availability-transport model that can reproduce such regime shifts and thus help facilitate sustainable reservoir operation and river management in wider cryospheric regions under future climate and hydrological change.
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Affiliation(s)
- Ting Zhang
- Key Laboratory for Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, China
- Department of Geography, National University of Singapore, Singapore, Singapore
| | - Dongfeng Li
- Key Laboratory for Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, China
- Department of Geography, National University of Singapore, Singapore, Singapore
| | - Amy E. East
- U.S. Geological Survey Pacific Coastal and Marine Science Center, Santa Cruz, CA, USA
| | - Albert J. Kettner
- CSDMS, Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA
| | - Jim Best
- Departments of Geology, Geography and GIS and Mechanical Science and Engineering, and Ven Te Chow Hydrosystems Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jinren Ni
- Key Laboratory for Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, China
| | - Xixi Lu
- Department of Geography, National University of Singapore, Singapore, Singapore
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5
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Varliero G, Lebre PH, Frey B, Fountain AG, Anesio AM, Cowan DA. Glacial Water: A Dynamic Microbial Medium. Microorganisms 2023; 11:1153. [PMID: 37317127 DOI: 10.3390/microorganisms11051153] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/15/2023] [Accepted: 04/19/2023] [Indexed: 06/16/2023] Open
Abstract
Microbial communities and nutrient dynamics in glaciers and ice sheets continuously change as the hydrological conditions within and on the ice change. Glaciers and ice sheets can be considered bioreactors as microbiomes transform nutrients that enter these icy systems and alter the meltwater chemistry. Global warming is increasing meltwater discharge, affecting nutrient and cell export, and altering proglacial systems. In this review, we integrate the current understanding of glacial hydrology, microbial activity, and nutrient and carbon dynamics to highlight their interdependence and variability on daily and seasonal time scales, as well as their impact on proglacial environments.
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Affiliation(s)
- Gilda Varliero
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Pedro H Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
| | - Beat Frey
- Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Andrew G Fountain
- Departments of Geology and Geography, Portland State University, Portland, OR 97212, USA
| | - Alexandre M Anesio
- Department of Environmental Science, iClimate, Aarhus University, DK-4000 Roskilde, Denmark
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0002, South Africa
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6
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Henson HC, Holding JM, Meire L, Rysgaard S, Stedmon CA, Stuart-Lee A, Bendtsen J, Sejr M. Coastal freshening drives acidification state in Greenland fjords. Sci Total Environ 2023; 855:158962. [PMID: 36170921 DOI: 10.1016/j.scitotenv.2022.158962] [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] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Greenland's fjords and coastal waters are highly productive and sustain important fisheries. However, retreating glaciers and increasing meltwater are changing fjord circulation and biogeochemistry, which may threaten future productivity. The freshening of Greenland fjords caused by unprecedented melting of the Greenland Ice Sheet may alter carbonate chemistry in coastal waters, influencing CO2 uptake and causing biological consequences from acidification. However, few studies to date explore the current acidification state in Greenland coastal waters. Here we present the first-ever large-scale measurements of carbonate system parameters in 16 Greenlandic fjords and seek to identify the drivers of acidification state in these freshening ecosystems. Aragonite saturation state (Ω), a proxy for ocean acidification, was calculated from dissolved inorganic carbon (DIC) and total alkalinity from fjords along the east and west coast of Greenland spanning 68-75°N. Aragonite saturation was primarily >1 in the surface mixed layer. However, undersaturated-or corrosive--conditions (Ω < 1) were observed on both coasts (west: Ω = 0.28-3.11, east: Ω = 0.70-3.07), albeit at different depths. West Greenland fjords were largely corrosive at depth while undersaturation in East Greenland fjords was only observed in surface waters. This reflects a difference in the coastal boundary conditions and mechanisms driving acidification state. We suggest that advection of Sub Polar Mode Water and accumulation of DIC from organic matter decomposition drive corrosive conditions in the West, while freshwater alkalinity dilution drives acidification in the East. The presence of marine terminating glaciers also impacted local acidification states by influencing fjord circulation: upwelling driven by subglacial discharge brought corrosive bottom waters to shallower depths. Meanwhile, discharge from land terminating glaciers strengthened stratification and diluted alkalinity. Regardless of the drivers in each system, increasing freshwater discharge will likely lower carbonate saturation states and impact biotic and abiotic carbon uptake in the future.
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Affiliation(s)
| | - Johnna M Holding
- Arctic Research Centre, Aarhus University, Denmark; Department of Ecoscience, Aarhus University, Denmark
| | - Lorenz Meire
- Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research, Yerseke, the Netherlands; Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland
| | | | - Colin A Stedmon
- National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | - Alice Stuart-Lee
- Department of Estuarine and Delta Systems, Royal Netherlands Institute for Sea Research, Yerseke, the Netherlands
| | - Jørgen Bendtsen
- Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - Mikael Sejr
- Arctic Research Centre, Aarhus University, Denmark; Department of Ecoscience, Aarhus University, Denmark
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7
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Carroll D, Menemenlis D, Dutkiewicz S, Lauderdale JM, Adkins JF, Bowman KW, Brix H, Fenty I, Gierach MM, Hill C, Jahn O, Landschützer P, Manizza M, Mazloff MR, Miller CE, Schimel DS, Verdy A, Whitt DB, Zhang H. Attribution of Space-Time Variability in Global-Ocean Dissolved Inorganic Carbon. Global Biogeochem Cycles 2022; 36:e2021GB007162. [PMID: 35865754 PMCID: PMC9286438 DOI: 10.1029/2021gb007162] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 02/27/2022] [Accepted: 03/08/2022] [Indexed: 06/15/2023]
Abstract
The inventory and variability of oceanic dissolved inorganic carbon (DIC) is driven by the interplay of physical, chemical, and biological processes. Quantifying the spatiotemporal variability of these drivers is crucial for a mechanistic understanding of the ocean carbon sink and its future trajectory. Here, we use the Estimating the Circulation and Climate of the Ocean-Darwin ocean biogeochemistry state estimate to generate a global-ocean, data-constrained DIC budget and investigate how spatial and seasonal-to-interannual variability in three-dimensional circulation, air-sea CO2 flux, and biological processes have modulated the ocean sink for 1995-2018. Our results demonstrate substantial compensation between budget terms, resulting in distinct upper-ocean carbon regimes. For example, boundary current regions have strong contributions from vertical diffusion while equatorial regions exhibit compensation between upwelling and biological processes. When integrated across the full ocean depth, the 24-year DIC mass increase of 64 Pg C (2.7 Pg C year-1) primarily tracks the anthropogenic CO2 growth rate, with biological processes providing a small contribution of 2% (1.4 Pg C). In the upper 100 m, which stores roughly 13% (8.1 Pg C) of the global increase, we find that circulation provides the largest DIC gain (6.3 Pg C year-1) and biological processes are the largest loss (8.6 Pg C year-1). Interannual variability is dominated by vertical advection in equatorial regions, with the 1997-1998 El Niño-Southern Oscillation causing the largest year-to-year change in upper-ocean DIC (2.1 Pg C). Our results provide a novel, data-constrained framework for an improved mechanistic understanding of natural and anthropogenic perturbations to the ocean sink.
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Affiliation(s)
- Dustin Carroll
- Moss Landing Marine LaboratoriesSan José State UniversityMoss LandingCAUSA
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | | | - Stephanie Dutkiewicz
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
- Center for Global Change ScienceMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Jonathan M. Lauderdale
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Jess F. Adkins
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - Kevin W. Bowman
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Holger Brix
- Joint Institute for Regional Earth System Science and EngineeringUniversity of California Los AngelesLos AngelesCAUSA
- Institute of Coastal Ocean DynamicsHelmholtz‐Zentrum HereonGeesthachtGermany
| | - Ian Fenty
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | | | - Chris Hill
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Oliver Jahn
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | | | - Manfredi Manizza
- Scripps Institution of OceanographyUniversity of California San DiegoLa JollaCAUSA
| | - Matt R. Mazloff
- Scripps Institution of OceanographyUniversity of California San DiegoLa JollaCAUSA
| | - Charles E. Miller
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - David S. Schimel
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
| | - Ariane Verdy
- Scripps Institution of OceanographyUniversity of California San DiegoLa JollaCAUSA
| | | | - Hong Zhang
- Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaCAUSA
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Campen HI, Arévalo-Martínez DL, Artioli Y, Brown IJ, Kitidis V, Lessin G, Rees AP, Bange HW. The role of a changing Arctic Ocean and climate for the biogeochemical cycling of dimethyl sulphide and carbon monoxide. Ambio 2022; 51:411-422. [PMID: 34480730 PMCID: PMC8692525 DOI: 10.1007/s13280-021-01612-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 04/27/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 05/20/2023]
Abstract
Dimethyl sulphide (DMS) and carbon monoxide (CO) are climate-relevant trace gases that play key roles in the radiative budget of the Arctic atmosphere. Under global warming, Arctic sea ice retreats at an unprecedented rate, altering light penetration and biological communities, and potentially affect DMS and CO cycling in the Arctic Ocean. This could have socio-economic implications in and beyond the Arctic region. However, little is known about CO production pathways and emissions in this region and the future development of DMS and CO cycling. Here we summarize the current understanding and assess potential future changes of DMS and CO cycling in relation to changes in sea ice coverage, light penetration, bacterial and microalgal communities, pH and physical properties. We suggest that production of DMS and CO might increase with ice melting, increasing light availability and shifting phytoplankton community. Among others, policy measures should facilitate large-scale process studies, coordinated long term observations and modelling efforts to improve our current understanding of the cycling and emissions of DMS and CO in the Arctic Ocean and of global consequences.
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Affiliation(s)
- Hanna I. Campen
- Department of Chemical Oceanography, GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Damian L. Arévalo-Martínez
- Department of Chemical Oceanography, GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Yuri Artioli
- Plymouth Marine Laboratory, Plymouth, PL1 3DH UK
| | - Ian J. Brown
- Plymouth Marine Laboratory, Plymouth, PL1 3DH UK
| | | | | | | | - Hermann W. Bange
- Department of Chemical Oceanography, GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
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9
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Kavan J, Tallentire GD, Demidionov M, Dudek J, Strzelecki MC. Fifty Years of Tidewater Glacier Surface Elevation and Retreat Dynamics along the South-East Coast of Spitsbergen (Svalbard Archipelago). Remote Sensing 2022; 14:354. [DOI: 10.3390/rs14020354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tidewater glaciers on the east coast of Svalbard were examined for surface elevation changes and retreat rate. An archival digital elevation model (DEM) from 1970 (generated from aerial images by the Norwegian Polar Institute) in combination with recent ArcticDEM were used to compare the surface elevation changes of eleven glaciers. This approach was complemented by a retreat rate estimation based on the analysis of Landsat and Sentinel-2 images. In total, four of the 11 tidewater glaciers became land-based due to the retreat of their termini. The remaining tidewater glaciers retreated at an average annual retreat rate of 48 m year−1, and with range between 10–150 m year−1. All the glaciers studied experienced thinning in their frontal zones with maximum surface elevation loss exceeding 100 m in the ablation areas of three glaciers. In contrast to the massive retreat and thinning of the frontal zones, a minor increase in ice thickness was recorded in some accumulation areas of the glaciers, exceeding 10 m on three glaciers. The change in glacier geometry suggests an important shift in glacier dynamics over the last 50 years, which very likely reflects the overall trend of increasing air temperatures. Such changes in glacier geometry are common at surging glaciers in their quiescent phase. Surging was detected on two glaciers studied, and was documented by the glacier front readvance and massive surface thinning in high elevated areas.
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Bertrand P, Bêty J, Yoccoz NG, Fortin MJ, Strøm H, Steen H, Kohler J, Harris SM, Patrick SC, Chastel O, Blévin P, Hop H, Moholdt G, Maton J, Descamps S. Fine-scale spatial segregation in a pelagic seabird driven by differential use of tidewater glacier fronts. Sci Rep 2021; 11:22109. [PMID: 34764330 DOI: 10.1038/s41598-021-01404-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022] Open
Abstract
In colonially breeding marine predators, individual movements and colonial segregation are influenced by seascape characteristics. Tidewater glacier fronts are important features of the Arctic seascape and are often described as foraging hotspots. Albeit their documented importance for wildlife, little is known about their structuring effect on Arctic predator movements and space use. In this study, we tested the hypothesis that tidewater glacier fronts can influence marine bird foraging patterns and drive spatial segregation among adjacent colonies. We analysed movements of black-legged kittiwakes (Rissa tridactyla) in a glacial fjord by tracking breeding individuals from five colonies. Although breeding kittiwakes were observed to travel up to ca. 280 km from the colony, individuals were more likely to use glacier fronts located closer to their colony and rarely used glacier fronts located farther away than 18 km. Such variation in the use of glacier fronts created fine-scale spatial segregation among the four closest (ca. 7 km distance on average) kittiwake colonies. Overall, our results support the hypothesis that spatially predictable foraging patches like glacier fronts can have strong structuring effects on predator movements and can modulate the magnitude of intercolonial spatial segregation in central-place foragers.
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11
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Sugiyama S, Minowa M, Fukamachi Y, Hata S, Yamamoto Y, Sauter T, Schneider C, Schaefer M. Subglacial discharge controls seasonal variations in the thermal structure of a glacial lake in Patagonia. Nat Commun 2021; 12:6301. [PMID: 34728649 DOI: 10.1038/s41467-021-26578-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 10/05/2021] [Indexed: 11/09/2022] Open
Abstract
Water temperature in glacial lakes affects underwater melting and calving of glaciers terminating in lakes. Despite its importance, seasonal lake temperature variations are poorly understood because taking long-term measurements near the front of calving glaciers is challenging. To investigate the thermal structure and its seasonal variations, we performed year-around temperature and current measurement at depths of 58–392 m in Lago Grey, a 410-m-deep glacial lake in Patagonia. The measurement revealed critical impacts of subglacial discharge on the lake thermal condition. Water below a depth of ~100 m showed the coldest temperature in mid-summer, under the influence of glacial discharge, whereas temperature in the upper layer followed a seasonal variation of air temperature. The boundary of the lower and upper layers was controlled by the depth of a sill which blocks outflow of dense and cold glacial meltwater. Our data implies that subglacial discharge and bathymetry dictate mass loss and the retreat of lake-terminating glaciers. The cold lakewater hinders underwater melting and facilitates formation of a floating terminus. Thermal conditions and circulation near glacier fronts are important to understand the recent rapid retreat of calving glaciers. New observations from a glacial lake suggesting a feedback mechanism between atmospheric warming, glacier front melting and calving for freshwater-terminating glaciers.
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12
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Szeligowska M, Trudnowska E, Boehnke R, Dąbrowska AM, Dragańska-Deja K, Deja K, Darecki M, Błachowiak-Samołyk K. The interplay between plankton and particles in the Isfjorden waters influenced by marine- and land-terminating glaciers. Sci Total Environ 2021; 780:146491. [PMID: 34030341 DOI: 10.1016/j.scitotenv.2021.146491] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 03/08/2021] [Accepted: 03/11/2021] [Indexed: 06/12/2023]
Abstract
Climate-induced glacial retreat in the Arctic results in an increased supply of meltwater with suspended terrigenous material into the marine environment. Despite increasing research efforts, effects of glacial retreat on functioning of plankton are not well documented and understood. Thus, we studied a hydro-optical seawater regime along with particle/plankton concentrations and composition structure in a high Arctic fjord (Isfjorden, West Spitsbergen) during mid-summer in 2019. This comprehensive study of the upper 50 m water layer presented a sharp distinction between 'muddy' waters influenced by glacial and river runoff and 'clear' open fjordic waters in the form of a notable difference in chlorophyll a concentrations, extent of euphotic zone depth, turbidity, inorganic/organic particle concentrations, and water colour. In this study, we present that the effects of glacial retreat on Arctic pelagial depend not only on different types of glaciers (marine- and land-terminating), but presumably, also on fjord topography and exposure to oceanic water inflow. The contrasting glacial, hydrological, and topographical conditions had different effects on the share of zooplankton and marine snow. Despite adaptation of the planktonic communities in the Arctic to high sediment loads and resultant light limitations, our study shows that continuing retreat of tidewater glaciers will have negative effect on planktonic communities especially in enclosed shallow fjord branches. Moreover, seawater darkening due to high turbidity could negatively affect tactile predators, such as gelatinous zooplankton. Additional division of plankton into functional groups typically used in the biogeochemical models demonstrated that diatoms, flagellates and mesozooplankton are influenced by suspended matter, whereas microzooplankton are highly adaptive to increased sediment loads. Since we investigated the largest Svalbard fjord system and incorporated multiple components of the pelagic realm, the current study delivers important recommendations for including marine snow and gelatinous zooplankton in ecosystem models applied in polar regions.
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Affiliation(s)
- Marlena Szeligowska
- Pelagic Biocenosis Functioning Laboratory, Marine Ecology Department, Institute of Oceanology Polish Academy of Sciences, Sopot, Poland.
| | - Emilia Trudnowska
- Pelagic Biocenosis Functioning Laboratory, Marine Ecology Department, Institute of Oceanology Polish Academy of Sciences, Sopot, Poland
| | - Rafał Boehnke
- Pelagic Biocenosis Functioning Laboratory, Marine Ecology Department, Institute of Oceanology Polish Academy of Sciences, Sopot, Poland
| | - Anna Maria Dąbrowska
- Marine Protists Laboratory, Marine Ecology Department, Institute of Oceanology Polish Academy of Sciences, Sopot, Poland
| | - Katarzyna Dragańska-Deja
- Remote Sensing Laboratory, Department of Marine Physics, Institute of Oceanology Polish Academy of Sciences, Sopot, Poland
| | - Kajetan Deja
- Benthic Ecology Laboratory, Marine Ecology Department, Institute of Oceanology Polish Academy of Sciences, Sopot, Poland
| | - Mirosław Darecki
- Remote Sensing Laboratory, Department of Marine Physics, Institute of Oceanology Polish Academy of Sciences, Sopot, Poland
| | - Katarzyna Błachowiak-Samołyk
- Pelagic Biocenosis Functioning Laboratory, Marine Ecology Department, Institute of Oceanology Polish Academy of Sciences, Sopot, Poland
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13
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Laufer-Meiser K, Michaud AB, Maisch M, Byrne JM, Kappler A, Patterson MO, Røy H, Jørgensen BB. Potentially bioavailable iron produced through benthic cycling in glaciated Arctic fjords of Svalbard. Nat Commun 2021; 12:1349. [PMID: 33649339 PMCID: PMC7921405 DOI: 10.1038/s41467-021-21558-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 01/28/2021] [Indexed: 01/31/2023] Open
Abstract
The Arctic has the highest warming rates on Earth. Glaciated fjord ecosystems, which are hotspots of carbon cycling and burial, are extremely sensitive to this warming. Glaciers are important for the transport of iron from land to sea and supply this essential nutrient to phytoplankton in high-latitude marine ecosystems. However, up to 95% of the glacially-sourced iron settles to sediments close to the glacial source. Our data show that while 0.6-12% of the total glacially-sourced iron is potentially bioavailable, biogeochemical cycling in Arctic fjord sediments converts the glacially-derived iron into more labile phases, generating up to a 9-fold increase in the amount of potentially bioavailable iron. Arctic fjord sediments are thus an important source of potentially bioavailable iron. However, our data suggests that as glaciers retreat onto land the flux of iron to the sediment-water interface may be reduced. Glacial retreat therefore likely impacts iron cycling in coastal marine ecosystems.
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Affiliation(s)
- Katja Laufer-Meiser
- grid.7048.b0000 0001 1956 2722Center for Geomicrobiology, Department of Biology, Aarhus University, Aarhus, Denmark ,grid.15649.3f0000 0000 9056 9663Present Address: GEOMAR, Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Alexander B. Michaud
- grid.7048.b0000 0001 1956 2722Center for Geomicrobiology, Department of Biology, Aarhus University, Aarhus, Denmark ,grid.296275.d0000 0000 9516 4913Present Address: Bigelow Laboratory for Ocean Sciences, Maine, USA
| | - Markus Maisch
- grid.10392.390000 0001 2190 1447Center for Applied Geosciences, University of Tübingen, Tübingen, Germany
| | - James M. Byrne
- grid.10392.390000 0001 2190 1447Center for Applied Geosciences, University of Tübingen, Tübingen, Germany ,grid.5337.20000 0004 1936 7603Present Address: School of Earth Sciences, University of Bristol, Wills Memorial Building, Bristol, UK
| | - Andreas Kappler
- grid.10392.390000 0001 2190 1447Center for Applied Geosciences, University of Tübingen, Tübingen, Germany ,grid.15649.3f0000 0000 9056 9663Present Address: GEOMAR, Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Molly O. Patterson
- grid.264260.40000 0001 2164 4508Department of Geological Sciences and Environmental Studies, Binghamton University, New York, USA
| | - Hans Røy
- grid.7048.b0000 0001 1956 2722Center for Geomicrobiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Bo Barker Jørgensen
- grid.7048.b0000 0001 1956 2722Center for Geomicrobiology, Department of Biology, Aarhus University, Aarhus, Denmark
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14
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Alcamán-Arias ME, Fuentes-Alburquenque S, Vergara-Barros P, Cifuentes-Anticevic J, Verdugo J, Polz M, Farías L, Pedrós-Alió C, Díez B. Coastal Bacterial Community Response to Glacier Melting in the Western Antarctic Peninsula. Microorganisms 2021; 9:microorganisms9010088. [PMID: 33401391 PMCID: PMC7823458 DOI: 10.3390/microorganisms9010088] [Citation(s) in RCA: 6] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 01/04/2023] Open
Abstract
Current warming in the Western Antarctic Peninsula (WAP) has multiple effects on the marine ecosystem, modifying the trophic web and the nutrient regime. In this study, the effect of decreased surface salinity on the marine microbial community as a consequence of freshening from nearby glaciers was investigated in Chile Bay, Greenwich Island, WAP. In the summer of 2016, samples were collected from glacier ice and transects along the bay for 16S rRNA gene sequencing, while in situ dilution experiments were conducted and analyzed using 16S rRNA gene sequencing and metatranscriptomic analysis. The results reveal that certain common seawater genera, such as Polaribacter, Pseudoalteromonas and HTCC2207, responded positively to decreased salinity in both the bay transect and experiments. The relative abundance of these bacteria slightly decreased, but their functional activity was maintained and increased the over time in the dilution experiments. However, while ice bacteria, such as Flavobacterium and Polaromonas, tolerated the increased salinity after mixing with seawater, their gene expression decreased considerably. We suggest that these bacterial taxa could be defined as sentinels of freshening events in the Antarctic coastal system. Furthermore, these results suggest that a significant portion of the microbial community is resilient and can adapt to disturbances, such as freshening due to the warming effect of climate change in Antarctica.
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Affiliation(s)
- María Estrella Alcamán-Arias
- Department of Oceanography, Universidad de Concepcion, Concepcion 4030000, Chile; (M.E.A.-A.); (L.F.)
- Center for Climate and Resilience Research (CR)2, Santiago 8320000, Chile
- Escuela de Medicina, Universidad Espíritu Santo, Guayaquil 0901952, Ecuador
| | - Sebastián Fuentes-Alburquenque
- Centro de Investigación en Recursos Naturales y Sustentabilidad, Universidad Bernardo O’Higgins, Santiago 8370993, Chile;
- Facultad de Ingeniería, Ciencia y Tecnología, Universidad Bernardo O’Higgins, Santiago 8370993, Chile
| | - Pablo Vergara-Barros
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile; (P.V.-B.); (J.C.-A.)
| | - Jerónimo Cifuentes-Anticevic
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile; (P.V.-B.); (J.C.-A.)
| | - Josefa Verdugo
- Alfred-Wegener-Institute, Helmholtz-Centre for Polar and Marine Research, 27570 Bremerhaven, Germany;
| | - Martin Polz
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;
| | - Laura Farías
- Department of Oceanography, Universidad de Concepcion, Concepcion 4030000, Chile; (M.E.A.-A.); (L.F.)
- Center for Climate and Resilience Research (CR)2, Santiago 8320000, Chile
| | - Carlos Pedrós-Alió
- Departamento de Biología de Sistemas, Centro Nacional de Biotecnología (CSIC), Darwin 3, 28049 Madrid, Spain;
| | - Beatriz Díez
- Center for Climate and Resilience Research (CR)2, Santiago 8320000, Chile
- Department of Molecular Genetics and Microbiology, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile; (P.V.-B.); (J.C.-A.)
- Correspondence:
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15
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Limoges A, Weckström K, Ribeiro S, Georgiadis E, Hansen KE, Martinez P, Seidenkrantz M, Giraudeau J, Crosta X, Massé G. Learning from the past: Impact of the Arctic Oscillation on sea ice and marine productivity off northwest Greenland over the last 9,000 years. Glob Chang Biol 2020; 26:6767-6786. [PMID: 32885894 PMCID: PMC7756419 DOI: 10.1111/gcb.15334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 06/11/2023]
Abstract
Climate warming is rapidly reshaping the Arctic cryosphere and ocean conditions, with consequences for sea ice and pelagic productivity patterns affecting the entire marine food web. To predict how ongoing changes will impact Arctic marine ecosystems, concerted effort from various disciplines is required. Here, we contribute multi-decadal reconstructions of changes in diatom production and sea-ice conditions in relation to Holocene climate and ocean conditions off northwest Greenland. Our multiproxy study includes diatoms, sea-ice biomarkers (IP25 and HBI III) and geochemical tracers (TOC [total organic carbon], TOC:TN [total nitrogen], δ13 C, δ15 N) from a sediment core record spanning the last c. 9,000 years. Our results suggest that the balance between the outflow of polar water from the Arctic, and input of Atlantic water from the Irminger Current into the West Greenland Current is a key factor in controlling sea-ice conditions, and both diatom phenology and production in northeastern Baffin Bay. Our proxy record notably shows that changes in sea-surface conditions initially forced by Neoglacial cooling were dynamically amplified by the shift in the dominant phase of the Arctic Oscillation (AO) mode that occurred at c. 3,000 yr BP, and caused drastic changes in community composition and a decline in diatom production at the study site. In the future, with projected dominant-positive AO conditions favored by Arctic warming, increased water column stratification may counteract the positive effect of a longer open-water growth season and negatively impact diatom production.
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Affiliation(s)
- Audrey Limoges
- Department of Earth SciencesUniversity of New BrunswickFrederictonNBCanada
| | - Kaarina Weckström
- Ecosystems and Environment Research Programme (ECRU), and Helsinki Institute of Sustainability ScienceHelsinki UniversityHelsinkiFinland
| | - Sofia Ribeiro
- Department of Glaciology and ClimateGeological Survey of Denmark and GreenlandCopenhagenDenmark
| | | | | | | | | | | | - Xavier Crosta
- Université de BordeauxCNRSEPHEUMR 5805 EPOCPessacFrance
| | - Guillaume Massé
- Université LavalCNRSUMI 3376 TAKUVIKQuébecQCCanada
- Station Marine de ConcarneauUMR7159 LOCEANConcarneauFrance
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16
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Pryer HV, Hawkings JR, Wadham JL, Robinson LF, Hendry KR, Hatton JE, Kellerman AM, Bertrand S, Gill‐Olivas B, Marshall MG, Brooker RA, Daneri G, Häussermann V. The Influence of Glacial Cover on Riverine Silicon and Iron Exports in Chilean Patagonia. Global Biogeochem Cycles 2020; 34:e2020GB006611. [PMID: 33519063 PMCID: PMC7818384 DOI: 10.1029/2020gb006611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 09/27/2020] [Accepted: 11/12/2020] [Indexed: 06/12/2023]
Abstract
Glaciated environments have been highlighted as important sources of bioavailable nutrients, with inputs of glacial meltwater potentially influencing productivity in downstream ecosystems. However, it is currently unclear how riverine nutrient concentrations vary across a spectrum of glacial cover, making it challenging to accurately predict how terrestrial fluxes will change with continued glacial retreat. Using 40 rivers in Chilean Patagonia as a unique natural laboratory, we investigate how glacial cover affects riverine Si and Fe concentrations, and infer how exports of these bioessential nutrients may change in the future. Dissolved Si (as silicic acid) and soluble Fe (<0.02 μm) concentrations were relatively low in glacier-fed rivers, whereas concentrations of colloidal-nanoparticulate (0.02-0.45 μm) Si and Fe increased significantly as a function of glacial cover. These colloidal-nanoparticulate phases were predominately composed of aluminosilicates and Fe-oxyhydroxides, highlighting the need for size-fractionated analyses and further research to quantify the lability of colloidal-nanoparticulate species. We also demonstrate the importance of reactive particulate (>0.45 μm) phases of both Si and Fe, which are not typically accounted for in terrestrial nutrient budgets but can dominate riverine exports. Dissolved Si and soluble Fe yield estimates showed no trend with glacial cover, suggesting no significant change in total exports with continued glacial retreat. However, yields of colloidal-nanoparticulate and reactive sediment-bound Si and Fe were an order of magnitude greater in highly glaciated catchments and showed significant positive correlations with glacial cover. As such, regional-scale exports of these phases are likely to decrease as glacial cover disappears across Chilean Patagonia, with potential implications for downstream ecosystems.
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Affiliation(s)
- Helena V. Pryer
- Bristol Glaciology Centre, Department of Geographical SciencesUniversity of BristolBristolUK
- School of Earth SciencesUniversity of BristolBristolUK
| | - Jon R. Hawkings
- Department of Earth, Ocean and Atmospheric SciencesFlorida State UniversityTallahasseeFLUSA
- German Research Centre for Geosciences GFZPotsdamGermany
| | - Jemma L. Wadham
- Bristol Glaciology Centre, Department of Geographical SciencesUniversity of BristolBristolUK
| | | | | | | | - Anne M. Kellerman
- Department of Earth, Ocean and Atmospheric SciencesFlorida State UniversityTallahasseeFLUSA
| | | | - Beatriz Gill‐Olivas
- Bristol Glaciology Centre, Department of Geographical SciencesUniversity of BristolBristolUK
| | - Matthew G. Marshall
- Bristol Glaciology Centre, Department of Geographical SciencesUniversity of BristolBristolUK
| | | | - Giovanni Daneri
- Centro de Investigación en Ecosistemas de la PatagoniaCoyhaiqueChile
- COPAS Sur‐AustralUniversidad de ConcepciónConcepciónChile
| | - Vreni Häussermann
- Huinay Scientific Field StationPontificia Universidad Católica de ValparaísoValparaísoChile
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17
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Tagklis F, Bracco A, Ito T, Castelao RM. Submesoscale modulation of deep water formation in the Labrador Sea. Sci Rep 2020; 10:17489. [PMID: 33060687 DOI: 10.1038/s41598-020-74345-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/29/2020] [Indexed: 11/09/2022] Open
Abstract
Submesoscale structures fill the ocean surface, and recent numerical simulations and indirect observations suggest that they may extend to the ocean interior. It remains unclear, however, how far-reaching their impact may be-in both space and time, from weather to climate scales. Here transport pathways and the ultimate fate of the Irminger Current water from the continental slope to Labrador Sea interior are investigated through regional ocean simulations. Submesoscale processes modulate this transport and in turn the stratification of the Labrador Sea interior, by controlling the characteristics of the coherent vortices formed along West Greenland. Submesoscale circulations modify and control the Labrador Sea contribution to the global meridional overturning, with a linear relationship between time-averaged near surface vorticity and/or frontogenetic tendency along the west coast of Greenland, and volume of convected water. This research puts into contest the lesser role of the Labrador Sea in the overall control of the state of the MOC argued through the analysis of recent OSNAP (Overturning in the Subpolar North Atlantic Program) data with respect to estimates from climate models. It also confirms that submesoscale turbulence scales-up to climate relevance, pointing to the urgency of including its advective contribution in Earth systems models.
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18
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Simon MH, Muschitiello F, Tisserand AA, Olsen A, Moros M, Perner K, Bårdsnes ST, Dokken TM, Jansen E. A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland. PLoS One 2020; 15:e0239373. [PMID: 32991577 DOI: 10.1371/journal.pone.0239373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/07/2020] [Indexed: 12/01/2022] Open
Abstract
Extending oceanographic data beyond the instrumental period is highly needed to better characterize and understand multi-decadal to centennial natural ocean variability. Here, a stable isotope record at unprecedented temporal resolution (1 to 2 years) from a new marine core retrieved off western North Iceland is presented. We aim to better constrain the variability of subsurface, Atlantic-derived Subpolar Mode Water (SPMW), using near surface-dwelling planktic foraminifera and Arctic Intermediate Water (AIW) mass changes using benthic foraminifera over the last ~165 years. The reconstruction overlaps in time with instrumental observations and a direct comparison reveals that the δ18O record of Neogloboquadrina pachyderma is reliably representing temperature fluctuations in the SPMWs. Trends in the N. pachyderma δ13C record match the measured phosphate concentration in the upper 200 m on the North Icelandic Shelf well. Near surface-dwelling foraminifera trace anthropogenic CO2 in the Iceland Sea by ~ 1950 ± 8, however, a reduced amplitude shift in the Marine Suess effect is identified. We argue that this is caused by a contemporary ongoing increase in marine primary productivity in the upper ocean due to enhanced Greenland’s freshwater discharge that has contributed to a nutrient-driven fertilization since the 1940s/50s (Perner et al., 2019). Multi-decadal variability is detected. We find that the 16-year periodicity evident in SPMW and AIWs based on the δ18O of N. pachyderma and M. barleeanum is a signal of SST anomalies propagated into the Nordic Seas via the Atlantic inflow branches around Iceland. Spectral analyses of the planktic foraminiferal δ13C signal indicate intermittent 30-year cycles that are likely reflecting the ocean response to atmospheric variability, presumably the East Atlantic Pattern. A long-term trend in benthic δ18O suggests that Atlantic-derived waters are expanding their core within the water column from the subsurface into deeper intermediate depths towards the present day. This is a result of increased transport by the North Icelandic Irminger Current to the North Iceland Shelf over the historical era.
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19
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Krisch S, Browning TJ, Graeve M, Ludwichowski KU, Lodeiro P, Hopwood MJ, Roig S, Yong JC, Kanzow T, Achterberg EP. The influence of Arctic Fe and Atlantic fixed N on summertime primary production in Fram Strait, North Greenland Sea. Sci Rep 2020; 10:15230. [PMID: 32943713 PMCID: PMC7499181 DOI: 10.1038/s41598-020-72100-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/25/2020] [Indexed: 11/14/2022] Open
Abstract
Climate change has led to a ~ 40% reduction in summer Arctic sea-ice cover extent since the 1970s. Resultant increases in light availability may enhance phytoplankton production. Direct evidence for factors currently constraining summertime phytoplankton growth in the Arctic region is however lacking. GEOTRACES cruise GN05 conducted a Fram Strait transect from Svalbard to the NE Greenland Shelf in summer 2016, sampling for bioessential trace metals (Fe, Co, Zn, Mn) and macronutrients (N, Si, P) at ~ 79°N. Five bioassay experiments were conducted to establish phytoplankton responses to additions of Fe, N, Fe + N and volcanic dust. Ambient nutrient concentrations suggested N and Fe were deficient in surface seawater relative to typical phytoplankton requirements. A west-to-east trend in the relative deficiency of N and Fe was apparent, with N becoming more deficient towards Greenland and Fe more deficient towards Svalbard. This aligned with phytoplankton responses in bioassay experiments, which showed greatest chlorophyll-a increases in + N treatment near Greenland and + N + Fe near Svalbard. Collectively these results suggest primary N limitation of phytoplankton growth throughout the study region, with conditions potentially approaching secondary Fe limitation in the eastern Fram Strait. We suggest that the supply of Atlantic-derived N and Arctic-derived Fe exerts a strong control on summertime nutrient stoichiometry and resultant limitation patterns across the Fram Strait region.
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Affiliation(s)
- Stephan Krisch
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Thomas J Browning
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Martin Graeve
- Alfred-Wegener-Institute for Polar and Marine Research, 27570, Bremerhaven, Germany
| | - Kai-Uwe Ludwichowski
- Alfred-Wegener-Institute for Polar and Marine Research, 27570, Bremerhaven, Germany
| | - Pablo Lodeiro
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Mark J Hopwood
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Stéphane Roig
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
| | - Jaw-Chuen Yong
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia
| | - Torsten Kanzow
- Alfred-Wegener-Institute for Polar and Marine Research, 27570, Bremerhaven, Germany
| | - Eric P Achterberg
- Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, 24148, Kiel, Germany.
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20
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Perner K, Moros M, Otterå OH, Blanz T, Schneider RR, Jansen E. An oceanic perspective on Greenland's recent freshwater discharge since 1850. Sci Rep 2019; 9:17680. [PMID: 31776367 PMCID: PMC6881324 DOI: 10.1038/s41598-019-53723-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 11/04/2019] [Indexed: 11/22/2022] Open
Abstract
Instrumental data evidence an accelerating freshwater release from Arctic sea ice export and the Greenland Ice Sheet over the past three decades causing cooling and freshening in the subpolar North Atlantic region. However, evaluating the observed acceleration on a historical oceanic and climatic perspective remains challenging given the short available instrumental time series. Here we provide a marine perspective on the freshwater releases to the ocean since 1850 as reflected in the northern limb of the Subpolar Gyre. Our reconstructions suggest that the recent acceleration tracks back to the 1940s/50s and is unprecedented since 1850. The melting, initiated by the 1920s natural rise in solar irradiance, accelerated in response to a combined effect of natural and anthropogenic forcing factors. We find that Greenland’s freshwater discharge has contributed to a nutrient-driven fertilization of the upper ocean and consequently increased the marine primary productivity since the 1940s/50s.
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Affiliation(s)
- Kerstin Perner
- Department of Marine Geology, Leibniz Institute for Baltic Sea Research, See Str. 15, 18119, Rostock, Germany. .,Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Allégaten 41, 5055, Bergen, Norway. .,NORCE Norwegian Research Centre AS, Bjerknes Centre for Climate Research, Jahnebakken 5, 5007, Bergen, Norway.
| | - Matthias Moros
- Department of Marine Geology, Leibniz Institute for Baltic Sea Research, See Str. 15, 18119, Rostock, Germany.
| | - Odd Helge Otterå
- NORCE Norwegian Research Centre AS, Bjerknes Centre for Climate Research, Jahnebakken 5, 5007, Bergen, Norway
| | - Thomas Blanz
- Institute of Geosciences, Kiel University, Ludwig-Meyn-Straße 10, 24118, Kiel, Germany
| | - Ralph R Schneider
- Institute of Geosciences, Kiel University, Ludwig-Meyn-Straße 10, 24118, Kiel, Germany
| | - Eystein Jansen
- Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Allégaten 41, 5055, Bergen, Norway. .,NORCE Norwegian Research Centre AS, Bjerknes Centre for Climate Research, Jahnebakken 5, 5007, Bergen, Norway.
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21
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Wadham JL, Hawkings JR, Tarasov L, Gregoire LJ, Spencer RGM, Gutjahr M, Ridgwell A, Kohfeld KE. Ice sheets matter for the global carbon cycle. Nat Commun 2019; 10:3567. [PMID: 31417076 PMCID: PMC6695407 DOI: 10.1038/s41467-019-11394-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 07/09/2019] [Indexed: 11/09/2022] Open
Abstract
The cycling of carbon on Earth exerts a fundamental influence upon the greenhouse gas content of the atmosphere, and hence global climate over millennia. Until recently, ice sheets were viewed as inert components of this cycle and largely disregarded in global models. Research in the past decade has transformed this view, demonstrating the existence of uniquely adapted microbial communities, high rates of biogeochemical/physical weathering in ice sheets and storage and cycling of organic carbon (>104 Pg C) and nutrients. Here we assess the active role of ice sheets in the global carbon cycle and potential ramifications of enhanced melt and ice discharge in a warming world.
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Affiliation(s)
- J L Wadham
- University of Bristol, Bristol, BS8 1TH, UK.
| | - J R Hawkings
- National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, 32306, USA
- German Research Centre for Geosciences GFZ, 14473, Potsdam, Germany
| | - L Tarasov
- Memorial University, St. John's, NF, A1B 3X9, Canada
| | | | - R G M Spencer
- National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, 32306, USA
| | | | - A Ridgwell
- University of California, Riverside, CA, 94720, USA
| | - K E Kohfeld
- Simon Fraser University, Burnaby, BC, 8888, Canada
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22
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Hatton JE, Hendry KR, Hawkings JR, Wadham JL, Opfergelt S, Kohler TJ, Yde JC, Stibal M, Žárský JD. Silicon isotopes in Arctic and sub-Arctic glacial meltwaters: the role of subglacial weathering in the silicon cycle. Proc Math Phys Eng Sci 2019; 475:20190098. [PMID: 31534420 PMCID: PMC6735475 DOI: 10.1098/rspa.2019.0098] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 07/16/2019] [Indexed: 11/12/2022] Open
Abstract
Glacial environments play an important role in high-latitude marine nutrient cycling, potentially contributing significant fluxes of silicon (Si) to the polar oceans, either as dissolved silicon (DSi) or as dissolvable amorphous silica (ASi). Silicon is a key nutrient in promoting marine primary productivity, contributing to atmospheric CO2 removal. We present the current understanding of Si cycling in glacial systems, focusing on the Si isotope (δ30Si) composition of glacial meltwaters. We combine existing glacial δ30Si data with new measurements from 20 sub-Arctic glaciers, showing that glacial meltwaters consistently export isotopically light DSi compared with non-glacial rivers (+0.16‰ versus +1.38‰). Glacial δ30SiASi composition ranges from −0.05‰ to −0.86‰ but exhibits low seasonal variability. Silicon fluxes and δ30Si composition from glacial systems are not commonly included in global Si budgets and isotopic mass balance calculations at present. We discuss outstanding questions, including the formation mechanism of ASi and the export of glacial nutrients from fjords. Finally, we provide a contextual framework for the recent advances in our understanding of subglacial Si cycling and highlight critical research avenues for assessing potential future changes in these environments.
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Affiliation(s)
- Jade E Hatton
- School of Earth Sciences, University of Bristol, Bristol, UK
| | | | - Jonathan R Hawkings
- National High Magnetic Field Lab and Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA.,German Research Centre for Geosciences GFZ, Potsdam, Germany
| | - Jemma L Wadham
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | - Sophie Opfergelt
- Earth and Life Institute, Environmental Sciences, Université Catholique de Louvain, L7.05.10, 1348, Louvain-la-Neuve, Belgium
| | - Tyler J Kohler
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia.,Stream Biofilm and Ecosystem Research Laboratory, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Jacob C Yde
- Department of Environmental Sciences, Western Norway University of Applied Sciences, Sogndal, Norway
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Jakub D Žárský
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
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23
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Sutherland DA, Jackson RH, Kienholz C, Amundson JM, Dryer WP, Duncan D, Eidam EF, Motyka RJ, Nash JD. Direct observations of submarine melt and subsurface geometry at a tidewater glacier. Science 2019; 365:369-374. [PMID: 31346063 DOI: 10.1126/science.aax3528] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/27/2019] [Indexed: 11/02/2022]
Abstract
Ice loss from the world's glaciers and ice sheets contributes to sea level rise, influences ocean circulation, and affects ecosystem productivity. Ongoing changes in glaciers and ice sheets are driven by submarine melting and iceberg calving from tidewater glacier margins. However, predictions of glacier change largely rest on unconstrained theory for submarine melting. Here, we use repeat multibeam sonar surveys to image a subsurface tidewater glacier face and document a time-variable, three-dimensional geometry linked to melting and calving patterns. Submarine melt rates are high across the entire ice face over both seasons surveyed and increase from spring to summer. The observed melt rates are up to two orders of magnitude greater than predicted by theory, challenging current simulations of ice loss from tidewater glaciers.
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Affiliation(s)
- D A Sutherland
- Department of Earth Sciences, University of Oregon, Eugene, OR 97403, USA.
| | - R H Jackson
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - C Kienholz
- Department of Natural Sciences, University of Alaska Southeast, Juneau, AK 99801, USA
| | - J M Amundson
- Department of Natural Sciences, University of Alaska Southeast, Juneau, AK 99801, USA
| | - W P Dryer
- Department of Natural Sciences, University of Alaska Southeast, Juneau, AK 99801, USA
| | - D Duncan
- Institute for Geophysics, University of Texas at Austin, Austin, TX 78758, USA
| | - E F Eidam
- Department of Marine Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
| | - R J Motyka
- Department of Natural Sciences, University of Alaska Southeast, Juneau, AK 99801, USA.,Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - J D Nash
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
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24
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Louropoulou E, Gledhill M, Browning TJ, Desai DK, Barraqueta JLM, Tonnard M, Sarthou G, Planquette H, Bowie AR, Schmitz RA, LaRoche J, Achterberg EP. Regulation of the Phytoplankton Heme b Iron Pool During the North Atlantic Spring Bloom. Front Microbiol 2019; 10:1566. [PMID: 31354666 PMCID: PMC6637849 DOI: 10.3389/fmicb.2019.01566] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/24/2019] [Indexed: 11/13/2022] Open
Abstract
Heme b is an iron-containing co-factor in hemoproteins. Heme b concentrations are low (<1 pmol L-1) in iron limited phytoplankton in cultures and in the field. Here, we determined heme b in marine particulate material (>0.7 μm) from the North Atlantic Ocean (GEOVIDE cruise - GEOTRACES section GA01), which spanned several biogeochemical regimes. We examined the relationship between heme b abundance and the microbial community composition, and its utility for mapping iron limited phytoplankton. Heme b concentrations ranged from 0.16 to 5.1 pmol L-1 (median = 2.0 pmol L-1, n = 62) in the surface mixed layer (SML) along the cruise track, driven mainly by variability in biomass. However, in the Irminger Basin, the lowest heme b levels (SML: median = 0.53 pmol L-1, n = 12) were observed, whilst the biomass was highest (particulate organic carbon, median = 14.2 μmol L-1, n = 25; chlorophyll a: median = 2.0 nmol L-1, n = 23) pointing to regulatory mechanisms of the heme b pool for growth conservation. Dissolved iron (DFe) was not depleted (SML: median = 0.38 nmol L-1, n = 11) in the Irminger Basin, but large diatoms (Rhizosolenia sp.) dominated. Hence, heme b depletion and regulation is likely to occur during bloom progression when phytoplankton class-dependent absolute iron requirements exceed the available ambient concentration of DFe. Furthermore, high heme b concentrations found in the Iceland Basin and Labrador Sea (median = 3.4 pmol L-1, n = 20), despite having similar DFe concentrations to the Irminger Basin, were attributed to an earlier growth phase of the extant phytoplankton populations. Thus, heme b provides a snapshot of the cellular activity in situ and could both be used as indicator of iron limitation and contribute to understanding phytoplankton adaptation mechanisms to changing iron supplies.
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Affiliation(s)
- Evangelia Louropoulou
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.,Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Martha Gledhill
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | | | - Dhwani K Desai
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Jan-Lukas Menzel Barraqueta
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.,Department of Earth Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Manon Tonnard
- UMR 6539/LEMAR/IUEM, CNRS, UBO, IRD, Ifremer, Brest, France.,Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, TAS, Australia.,Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | | | | | - Andrew R Bowie
- Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, TAS, Australia.,Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Ruth A Schmitz
- Institute for General Microbiology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Julie LaRoche
- Department of Biology, Dalhousie University, Halifax, NS, Canada
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25
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Łepkowska E, Stachnik Ł. Which Drivers Control the Suspended Sediment Flux in a High Arctic Glacierized Basin (Werenskioldbreen, Spitsbergen)? Water 2018; 10:1408. [DOI: 10.3390/w10101408] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A unique data set of suspended sediment transport from the Breelva, which drains the Werenskioldbreen (Southwestern Spitsbergen), is reported for the period 2007–2012. This basin is thoroughly described hydrologically, glaciologically, and chemically. However, until now there was a lack of full recognition of mechanical denudation. This study extends the information on quantitative suspended sediment load (SSL), amounting to 37.30–130.94 kt per year, and also underlines the importance of its modification by high discharge events, triggered by intense snowmelt or heavy rainfall. The large floods during the hydrologically active season transported even 83% of the total SSL. The variability of the SSL is controlled by glacial storage and release mechanisms. Particularly interesting is the second half of the hydrologically active season when intense rainfall events plays a key role in shaping the sediment supply pattern. The main source of fine mineral matter is the basal moraine, drained by subglacial outflows. Their higher mobilization occurs when the hydrostatic pressure increases, often as a result of rainwater supply to the glacier system. An increasing precipitation trend for Hornsund fjord region determines a positive trend predicted for sediment flux.
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