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Wietz M, Engel A, Ramondenc S, Niwano M, von Appen WJ, Priest T, von Jackowski A, Metfies K, Bienhold C, Boetius A. The Arctic summer microbiome across Fram Strait: Depth, longitude, and substrate concentrations structure microbial diversity in the euphotic zone. Environ Microbiol 2024; 26:e16568. [PMID: 38268397 DOI: 10.1111/1462-2920.16568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/12/2023] [Indexed: 01/26/2024]
Abstract
The long-term dynamics of microbial communities across geographic, hydrographic, and biogeochemical gradients in the Arctic Ocean are largely unknown. To address this, we annually sampled polar, mixed, and Atlantic water masses of the Fram Strait (2015-2019; 5-100 m depth) to assess microbiome composition, substrate concentrations, and oceanographic parameters. Longitude and water depth were the major determinants (~30%) of microbial community variability. Bacterial alpha diversity was highest in lower-photic polar waters. Community composition shifted from west to east, with the prevalence of, for example, Dadabacteriales and Thiotrichales in Arctic- and Atlantic-influenced waters, respectively. Concentrations of dissolved organic carbon peaked in the western, compared to carbohydrates in the chlorophyll-maximum of eastern Fram Strait. Interannual differences due to the time of sampling, which varied between early (June 2016/2018) and late (September 2019) phytoplankton bloom stages, illustrated that phytoplankton composition and resulting availability of labile substrates influence bacterial dynamics. We identified 10 species clusters with stable environmental correlations, representing signature populations of distinct ecosystem states. In context with published metagenomic evidence, our microbial-biogeochemical inventory of a key Arctic region establishes a benchmark to assess ecosystem dynamics and the imprint of climate change.
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Affiliation(s)
- Matthias Wietz
- Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Anja Engel
- Biological Oceanography, GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
| | - Simon Ramondenc
- Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Matomo Niwano
- Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Wilken-Jon von Appen
- Physical Oceanography of the Polar Seas, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Taylor Priest
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Anabel von Jackowski
- Biological Oceanography, GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
| | - Katja Metfies
- Polar Biological Oceanography, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg, Oldenburg, Germany
| | - Christina Bienhold
- Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Antje Boetius
- Deep-Sea Ecology and Technology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
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2
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Lu X, Hu Y, Omar A, Yang Y, Vaughan M, Lee Z, Neumann T, Trepte C, Getzewich B. Lidar attenuation coefficient in the global oceans: insights from ICESat-2 mission. OPTICS EXPRESS 2023; 31:29107-29118. [PMID: 37710717 DOI: 10.1364/oe.498053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/01/2023] [Indexed: 09/16/2023]
Abstract
The attenuation coefficient of natural waters plays a significant role in our understanding of hydrology from both the oceanographic and biological point of view. The advent of near-continuous observations by sophisticated space-based lidars now offers an unprecedented opportunity to characterize attenuation coefficients over open oceans on global and regional scales. At present, however, literature reports of lidar-derived attenuation coefficient estimates (klidar, m-1) in oceanic waters are very limited. In this study, we present a global survey of klidar derived from ATLAS/ICESat-2 nighttime measurements. Our results augment the existing passive sensor ocean color data set with a new diurnal component and extend the record to now include previously unavailable polar nighttime observations. The values of ATLAS measured klidar at 532 nm are between 0.045 and 0.39 m-1 with the higher values (>0.15 m-1) correlated with coastal waters and sea ice covered oceans. The average klidar in clearest oligotrophic ocean gyres is ∼0.058 ± 0.012 m-1 at 532 nm. The results reported here demonstrate the feasibility of using ATLAS/ICESat-2 lidar measurements for global klidar studies, which will in turn provide critical insights that enable climate models to correctly describe the amount of light present under sea ice, and for heat deposition studies in the upper ocean.
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Salavatian S, Robbins EM, Kuwabara Y, Castagnola E, Cui XT, Mahajan A. Real-time in vivo thoracic spinal glutamate sensing reveals spinal hyperactivity during myocardial ischemia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.11.531911. [PMID: 36993301 PMCID: PMC10054946 DOI: 10.1101/2023.03.11.531911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Myocardial ischemia-reperfusion (IR) can cause ventricular arrhythmias and sudden cardiac death via sympathoexcitation. The spinal cord neural network is crucial in triggering these arrhythmias and evaluating its neurotransmitter activity during IR is critical for understanding ventricular excitability control. To assess the real-time in vivo spinal neural activity in a large animal model, we developed a flexible glutamate-sensing multielectrode array. To record the glutamate signaling during IR injury, we inserted the probe into the dorsal horn of the thoracic spinal cord at the T2-T3 where neural signals generated by the cardiac sensory neurons are processed and provide sympathoexcitatory feedback to the heart. Using the glutamate sensing probe, we found that the spinal neural network was excited during IR, especially after 15 mins, and remained elevated during reperfusion. Higher glutamate signaling was correlated with the reduction in the cardiac myocyte activation recovery interval, showing higher sympathoexcitation, as well as dispersion of the repolarization which is a marker for increased risk of arrhythmias. This study illustrates a new technique for measuring the spinal glutamate at different spinal cord levels as a surrogate for the spinal neural network activity during cardiac interventions that engage the cardio-spinal neural pathway. Graphical abstract
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4
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Smith RA, Fort J, Legagneux P, Chastel O, Mallory ML, Bustamante P, Danielsen J, Hanssen SA, Einar Jónsson J, Magnúsdóttir E, Moe B, Parenteau C, Parkinson KJL, Parsons GJ, Tertitski G, Love OP. Do foraging ecology and contaminants interactively predict parenting hormone levels in common eider? Gen Comp Endocrinol 2023; 337:114261. [PMID: 36907529 DOI: 10.1016/j.ygcen.2023.114261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023]
Abstract
Global climate change is causing abiotic shifts such as higher air and ocean temperatures, and disappearing sea ice in Arctic ecosystems. These changes influence Arctic-breeding seabird foraging ecology by altering prey availability and selection, affecting individual body condition, reproductive success, and exposure to contaminants such as mercury (Hg). The cumulative effects of alterations to foraging ecology and Hg exposure may interactively alter the secretion of key reproductive hormones such as prolactin (PRL), important for parental attachment to eggs and offspring and overall reproductive success. However, more research is needed to investigate the relationships between these potential links. Using data collected from 106 incubating female common eiders (Somateria mollissima) at six Arctic and sub-Arctic colonies, we examined whether the relationship between individual foraging ecology (assessed using δ13C, δ15N) and total Hg (THg) exposure predicted PRL levels. We found a significant, complex interaction between δ13C, δ15N and THg on PRL, suggesting that individuals cumulatively foraging at lower trophic levels, in phytoplankton-dominant environments, and with the highest THg levels had the most constant significant relationship PRL levels. Cumulatively, these three interactive variables resulted in lowered PRL. Overall, results demonstrate the potential downstream and cumulative implications of environmentally induced changes in foraging ecology, in combination with THg exposure, on hormones known to influence reproductive success in seabirds. These findings are notable in the context of continuing environmental and food web changes in Arctic systems, which may make seabird populations more susceptible to ongoing stressors.
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Affiliation(s)
- Reyd A Smith
- University of Windsor, Windsor, Ontario N9B 3P4, Canada.
| | - Jérôme Fort
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, 17000 La Rochelle, France
| | - Pierre Legagneux
- Université Laval, Département de Biologie and Centre d'Études Nordiques, Québec City, Québec G1V 0A6, Canada; Centre d'Études Biologiques de Chizé, UMR 7372 CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Olivier Chastel
- Centre d'Études Biologiques de Chizé, UMR 7372 CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Mark L Mallory
- Acadia University, Wolfville, Nova Scotia B4P 2R6, Canada
| | - Paco Bustamante
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle Université, 17000 La Rochelle, France; Institut Universitaire de France (IUF), 1 rue Descartes, 75005 Paris, France
| | | | - Sveinn A Hanssen
- Norwegian Institute for Nature Research, Sognsveien 68, N-0855 Oslo, Norway
| | - Jón Einar Jónsson
- University of Iceland's Research Centre at Snæfellsnes, Hafnargata 3, 340, Stykkishólmur, Iceland
| | - Ellen Magnúsdóttir
- University of Iceland's Research Centre at Snæfellsnes, Hafnargata 3, 340, Stykkishólmur, Iceland
| | - Børge Moe
- Norwegian Institute for Nature Research, PB 5685 Torgarden, N-7485 Trondheim, Norway
| | - Charline Parenteau
- Centre d'Études Biologiques de Chizé, UMR 7372 CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
| | | | - Glen J Parsons
- Nova Scotia Department of Natural Resources and Renewables, Kentville, Nova Scotia B4N 4E5, Canada
| | - Grigori Tertitski
- Institute of Geography of the Russian Academy of Sciences, Moscow 119017, Russian Federation
| | - Oliver P Love
- University of Windsor, Windsor, Ontario N9B 3P4, Canada
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5
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Castellani G, Veyssière G, Karcher M, Stroeve J, Banas SN, Bouman AH, Brierley SA, Connan S, Cottier F, Große F, Hobbs L, Katlein C, Light B, McKee D, Orkney A, Proud R, Schourup-Kristensen V. Shine a light: Under-ice light and its ecological implications in a changing Arctic Ocean. AMBIO 2022; 51:307-317. [PMID: 34822117 PMCID: PMC8692516 DOI: 10.1007/s13280-021-01662-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/11/2021] [Accepted: 10/26/2021] [Indexed: 05/25/2023]
Abstract
The Arctic marine ecosystem is shaped by the seasonality of the solar cycle, spanning from 24-h light at the sea surface in summer to 24-h darkness in winter. The amount of light available for under-ice ecosystems is the result of different physical and biological processes that affect its path through atmosphere, snow, sea ice and water. In this article, we review the present state of knowledge of the abiotic (clouds, sea ice, snow, suspended matter) and biotic (sea ice algae and phytoplankton) controls on the underwater light field. We focus on how the available light affects the seasonal cycle of primary production (sympagic and pelagic) and discuss the sensitivity of ecosystems to changes in the light field based on model simulations. Lastly, we discuss predicted future changes in under-ice light as a consequence of climate change and their potential ecological implications, with the aim of providing a guide for future research.
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Affiliation(s)
- Giulia Castellani
- Alfred-Wegener-Institute Helmholtz-Zentrum für Polar und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Gaëlle Veyssière
- British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET UK
| | - Michael Karcher
- Alfred-Wegener-Institute Helmholtz-Zentrum für Polar und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
- Ocean Atmosphere Systems GmbH, Tewessteg 4, 20249 Hamburg, Germany
| | - Julienne Stroeve
- University College London, Gower St, London, WC1E 6BT UK
- University of Manitoba, 66 Chancellors Cir, Winnipeg, MB R3T 2N2 Canada
- National Snow and Ice Data Center CIRES, 449 UCB University of Colorado, Boulder, CO 80309-0449 USA
| | - S. Neil Banas
- University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH UK
| | | | - S. Andrew Brierley
- Pelagic Ecology Research Group, Scottish Oceans Institute, Gatty Marine Laboratory, School of Biology, University of St Andrews, Fife, KY16 8LB Scotland, UK
| | - Stacey Connan
- University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH UK
| | - Finlo Cottier
- Scottish Association for Marine Science, Oban, Argyll and Bute, PA37 1QA Scotland, UK
| | - Fabian Große
- University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH UK
- German Federal Institute of Hydrology, Department for Microbilogy, Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - Laura Hobbs
- University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH UK
| | - Christian Katlein
- Alfred-Wegener-Institute Helmholtz-Zentrum für Polar und Meeresforschung, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | | | - David McKee
- University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow, G1 1XH UK
| | - Andrew Orkney
- University of Oxford, South Parks Road, Oxford, OX1 3AN UK
| | - Roland Proud
- Pelagic Ecology Research Group, Scottish Oceans Institute, Gatty Marine Laboratory, School of Biology, University of St Andrews, Fife, KY16 8LB Scotland, UK
| | - Vibe Schourup-Kristensen
- Department of Applied Marine Ecology and Modeling, Aarhus University, Nordre Ringgade 1, 8000 Aarhus C, Denmark
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6
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Waga H, Eicken H, Hirawake T, Fukamachi Y. Variability in spring phytoplankton blooms associated with ice retreat timing in the Pacific Arctic from 2003-2019. PLoS One 2021; 16:e0261418. [PMID: 34914776 PMCID: PMC8675671 DOI: 10.1371/journal.pone.0261418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 12/01/2021] [Indexed: 12/02/2022] Open
Abstract
The Arctic is experiencing rapid changes in sea-ice seasonality and extent, with significant consequences for primary production. With the importance of accurate monitoring of spring phytoplankton dynamics in a changing Arctic, this study further examines the previously established critical relationship between spring phytoplankton bloom types and timing of the sea-ice retreat for broader temporal and spatial coverages, with a particular focus on the Pacific Arctic for 2003–2019. To this end, time-series of satellite-retrieved phytoplankton biomass were modeled using a parametric Gaussian function, as an effective approach to capture the development and decay of phytoplankton blooms. Our sensitivity analysis demonstrated accurate estimates of timing and presence/absence of peaks in phytoplankton biomass even with some missing values, suggesting the parametric Gaussian function is a powerful tool for capturing the development and decay of phytoplankton blooms. Based on the timing and presence/absence of a peak in phytoplankton biomass and following the classification developed by the previous exploratory work, spring bloom types are classified into three groups (under-ice blooms, probable under-ice blooms, and marginal ice zone blooms). Our results showed that the proportion of under-ice blooms was higher in the Chukchi Sea than in the Bering Sea. The probable under-ice blooms registered as the dominant bloom types in a wide area of the Pacific Arctic, whereas the marginal ice zone bloom was a relatively minor bloom type across the Pacific Arctic. Associated with a shift of sea-ice retreat timing toward earlier dates, we confirmed previous findings from the Chukchi Sea of recent shifts in phytoplankton bloom types from under-ice blooms to marginal ice zone blooms and demonstrated that this pattern holds for the broader Pacific Arctic sector for the time period 2003–2019. Overall, the present study provided additional evidence of the changing sea-ice retreat timing that can drive variations in phytoplankton bloom dynamics, which contributes to addressing the detection and consistent monitoring of the biophysical responses to the changing environments in the Pacific Arctic.
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Affiliation(s)
- Hisatomo Waga
- International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
- Arctic Research Center, Hokkaido University, Sapporo, Hokkaido, Japan
- * E-mail:
| | - Hajo Eicken
- International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Toru Hirawake
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido, Japan
| | - Yasushi Fukamachi
- Arctic Research Center, Hokkaido University, Sapporo, Hokkaido, Japan
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Rubin S, Crucifix M. Earth's Complexity Is Non-Computable: The Limits of Scaling Laws, Nonlinearity and Chaos. ENTROPY 2021; 23:e23070915. [PMID: 34356456 PMCID: PMC8306869 DOI: 10.3390/e23070915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 11/16/2022]
Abstract
Current physics commonly qualifies the Earth system as 'complex' because it includes numerous different processes operating over a large range of spatial scales, often modelled as exhibiting non-linear chaotic response dynamics and power scaling laws. This characterization is based on the fundamental assumption that the Earth's complexity could, in principle, be modeled by (surrogated by) a numerical algorithm if enough computing power were granted. Yet, similar numerical algorithms also surrogate different systems having the same processes and dynamics, such as Mars or Jupiter, although being qualitatively different from the Earth system. Here, we argue that understanding the Earth as a complex system requires a consideration of the Gaia hypothesis: the Earth is a complex system because it instantiates life-and therefore an autopoietic, metabolic-repair (M,R) organization-at a planetary scale. This implies that the Earth's complexity has formal equivalence to a self-referential system that inherently is non-algorithmic and, therefore, cannot be surrogated and simulated in a Turing machine. We discuss the consequences of this, with reference to in-silico climate models, tipping points, planetary boundaries, and planetary feedback loops as units of adaptive evolution and selection.
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Lu M, Wang S, Wang T, Hu S, Bhayana B, Ishii M, Kong Y, Cai Y, Dai T, Cui W, Wu MX. Bacteria-specific phototoxic reactions triggered by blue light and phytochemical carvacrol. Sci Transl Med 2021; 13:13/575/eaba3571. [PMID: 33408183 DOI: 10.1126/scitranslmed.aba3571] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 06/26/2020] [Accepted: 11/16/2020] [Indexed: 12/15/2022]
Abstract
Development of alternatives to antibiotics is one of the top priorities in the battle against multidrug-resistant (MDR) bacterial infections. Here, we report that two naturally occurring nonantibiotic modalities, blue light and phytochemical carvacrol, synergistically kill an array of bacteria including their planktonic forms, mature biofilms, and persisters, irrespective of their antibiotic susceptibility. Combination but not single treatment completely or substantially cured acute and established biofilm-associated Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus infections of full thickness murine third-degree burn wounds and rescued mice from lethal Pseudomonas aeruginosa skin wound infections. The combined therapy diminished bacterial colony-forming units as high as 7.5 log10 within 30 min and introduced few adverse events in the survival of cocultured mammalian cells, wound healing, or host DNA. Mechanistic studies revealed that carvacrol was photocatalytically oxidized into a series of photoreactive substrates that underwent photolysis or additional photosensitization reactions in response to the same blue light, forming two autoxidation cycles that interacted with each other resulting in robust generation of cytotoxic reactive oxygen species. This phototoxic reaction took place exclusively in bacteria, initiated by blue light excitation of endogenous porphyrin-like molecules abundantly produced in bacteria compared with mammalian cells. Moreover, no bacterial resistance developed to the combined treatment after 20 successive passages. This highly selective phototoxic reaction confers a unique strategy to combat the growing threat of MDR bacteria.
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Affiliation(s)
- Min Lu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA.,Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P. R. China
| | - Shen Wang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Tao Wang
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P. R. China
| | - Sisi Hu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Brijesh Bhayana
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Momoko Ishii
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Yifei Kong
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Yuchen Cai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Wenguo Cui
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P. R. China.
| | - Mei X Wu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA.
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9
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Feltracco M, Barbaro E, Spolaor A, Vecchiato M, Callegaro A, Burgay F, Vardè M, Maffezzoli N, Dallo F, Scoto F, Zangrando R, Barbante C, Gambaro A. Year-round measurements of size-segregated low molecular weight organic acids in Arctic aerosol. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 763:142954. [PMID: 33498125 DOI: 10.1016/j.scitotenv.2020.142954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 06/12/2023]
Abstract
Organic acids in aerosols Earth's atmosphere are ubiquitous and they have been extensively studied across urban, rural and polar environments. However, little is known about their properties, transport, source and seasonal variations in the Svalbard Archipelago. Here, we present the annual trend of organic acids in the aerosol collected at Ny-Ålesund and consider their size-distributions to infer their possible sources and relative contributions. A series of carboxylic acids were detected with a predominance of C2-oxalic acid. Pinic acid and cis-pinonic acid were studied in order to better understand the oxidative and gas-to-particle processes occurred in the Arctic atmosphere. Since the water-soluble organic fraction is mainly composed by organic acids and ions, we investigated how the seasonal variation leads to different atmospheric transport mechanisms, focusing on the chemical variations between the polar night and boreal summer. Using major ions, levoglucosan and MSA, the Positive Matrix Factorization (PMF) identified five different possible sources: a) sea spray; b) marine primary production; c) biomass burning; d) sea ice related process and e) secondary products.
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Affiliation(s)
- Matteo Feltracco
- Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy.
| | - Elena Barbaro
- Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy; Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy
| | - Andrea Spolaor
- Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy; Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy
| | - Marco Vecchiato
- Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy
| | - Alice Callegaro
- Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy
| | - François Burgay
- Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy; Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Massimiliano Vardè
- Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy; Department of Chemical and Pharmaceutical Sciences, University of Ferrara, via L. Borsari 46, Ferrara 44121, Italy
| | - Niccolò Maffezzoli
- Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy
| | - Federico Dallo
- Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy
| | - Federico Scoto
- Institute of Atmospheric Sciences and Climate, National Research Council of Italy (ISAC-CNR), SP Lecce-Monteroni Km 1.2, 73100 Lecce, Italy
| | - Roberta Zangrando
- Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy
| | - Carlo Barbante
- Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy; Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy
| | - Andrea Gambaro
- Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Via Torino 155, 30172 Venice, Italy; Institute of Polar Sciences - National Research Council of Italy (ISP-CNR), Via Torino 155, 30172 Venice, Italy
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10
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An under-ice bloom of mixotrophic haptophytes in low nutrient and freshwater-influenced Arctic waters. Sci Rep 2021; 11:2915. [PMID: 33536514 PMCID: PMC7858608 DOI: 10.1038/s41598-021-82413-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/20/2021] [Indexed: 11/08/2022] Open
Abstract
The pelagic spring bloom is essential for Arctic marine food webs, and a crucial driver of carbon transport to the ocean depths. A critical challenge is understanding its timing and magnitude, to predict its changes in coming decades. Spring bloom onset is typically light-limited, beginning when irradiance increases or during ice breakup. Here we report an acute 9-day under-ice algal bloom in nutrient-poor, freshwater-influenced water under 1-m thick sea ice. It was dominated by mixotrophic brackish water haptophytes (Chrysochromulina/ Prymnesium) that produced 5.7 g C m-2 new production. This estimate represents about half the annual pelagic production, occurring below sea ice with a large contribution from the mixotrophic algae bloom. The freshwater-influenced, nutrient-dilute and low light environment combined with mixotrophic community dominance implies that phagotrophy played a critical role in the under-ice bloom. We argue that such blooms dominated by potentially toxic mixotrophic algae might become more common and widespread in the future Arctic Ocean.
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11
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Yurkowski DJ, Brown TA, Blanchfield PJ, Ferguson SH. Atlantic walrus signal latitudinal differences in the long-term decline of sea ice-derived carbon to benthic fauna in the Canadian Arctic. Proc Biol Sci 2020; 287:20202126. [PMID: 33290685 DOI: 10.1098/rspb.2020.2126rspb20202126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Climate change is altering the biogeochemical and physical characteristics of the Arctic marine environment, which impacts sea ice algal and phytoplankton bloom dynamics and the vertical transport of these carbon sources to benthic communities. Little is known about whether the contribution of sea ice-derived carbon to benthic fauna and nitrogen cycling has changed over multiple decades in concert with receding sea ice. We combined compound-specific stable isotope analysis of amino acids with highly branched isoprenoid diatom lipid biomarkers using archived (1982-2016) tissue of benthivorous Atlantic walrus to examine temporal trends of sea ice-derived carbon, nitrogen isotope baseline and trophic position of Atlantic walrus at high- and mid-latitudes in the Canadian Arctic. Associated with an 18% sea ice decline in the mid-Arctic, sea ice-derived carbon contribution to Atlantic walrus decreased by 75% suggesting a strong decoupling of sea ice-benthic habitats. By contrast, a nearly exclusive amount of sea ice-derived carbon was maintained in high-Arctic Atlantic walrus (98% in 1996 and 89% in 2006) despite a similar percentage in sea ice reduction. Nitrogen isotope baseline or the trophic position of Atlantic walrus did not change over time at either location. These findings indicate latitudinal differences in the restructuring of carbon energy sources used by Atlantic walrus and their benthic prey, and in turn a change in Arctic marine ecosystem functioning between sea ice-pelagic-benthic habitats.
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Affiliation(s)
| | - Thomas A Brown
- Scottish Association for Marine Science, Oban PA37 1QA, UK
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12
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Yurkowski DJ, Brown TA, Blanchfield PJ, Ferguson SH. Atlantic walrus signal latitudinal differences in the long-term decline of sea ice-derived carbon to benthic fauna in the Canadian Arctic. Proc Biol Sci 2020; 287:20202126. [PMID: 33290685 PMCID: PMC7739943 DOI: 10.1098/rspb.2020.2126] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/16/2020] [Indexed: 11/28/2022] Open
Abstract
Climate change is altering the biogeochemical and physical characteristics of the Arctic marine environment, which impacts sea ice algal and phytoplankton bloom dynamics and the vertical transport of these carbon sources to benthic communities. Little is known about whether the contribution of sea ice-derived carbon to benthic fauna and nitrogen cycling has changed over multiple decades in concert with receding sea ice. We combined compound-specific stable isotope analysis of amino acids with highly branched isoprenoid diatom lipid biomarkers using archived (1982-2016) tissue of benthivorous Atlantic walrus to examine temporal trends of sea ice-derived carbon, nitrogen isotope baseline and trophic position of Atlantic walrus at high- and mid-latitudes in the Canadian Arctic. Associated with an 18% sea ice decline in the mid-Arctic, sea ice-derived carbon contribution to Atlantic walrus decreased by 75% suggesting a strong decoupling of sea ice-benthic habitats. By contrast, a nearly exclusive amount of sea ice-derived carbon was maintained in high-Arctic Atlantic walrus (98% in 1996 and 89% in 2006) despite a similar percentage in sea ice reduction. Nitrogen isotope baseline or the trophic position of Atlantic walrus did not change over time at either location. These findings indicate latitudinal differences in the restructuring of carbon energy sources used by Atlantic walrus and their benthic prey, and in turn a change in Arctic marine ecosystem functioning between sea ice-pelagic-benthic habitats.
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13
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Solan M, Archambault P, Renaud PE, März C. The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2020; 378:20200266. [PMID: 32862816 PMCID: PMC7481657 DOI: 10.1098/rsta.2020.0266] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Affiliation(s)
- Martin Solan
- School of Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK
- e-mail:
| | - Philippe Archambault
- ArcticNet, Québec Océan, Takuvik, Département de biologie, Université Laval, Québec, Canada
| | - Paul E. Renaud
- Akvaplan-niva, Fram Center for Climate and the Environment, 9296 Tromsø, Norway
- University Centre in Svalbard, Arctic Biology, 9171 Longyearbyen, Norway
| | - Christian März
- School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK
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14
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Randelhoff A, Lacour L, Marec C, Leymarie E, Lagunas J, Xing X, Darnis G, Penkerc'h C, Sampei M, Fortier L, D'Ortenzio F, Claustre H, Babin M. Arctic mid-winter phytoplankton growth revealed by autonomous profilers. SCIENCE ADVANCES 2020; 6:6/39/eabc2678. [PMID: 32978152 PMCID: PMC7518875 DOI: 10.1126/sciadv.abc2678] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
It is widely believed that during winter and spring, Arctic marine phytoplankton cannot grow until sea ice and snow cover start melting and transmit sufficient irradiance, but there is little observational evidence for that paradigm. To explore the life of phytoplankton during and after the polar night, we used robotic ice-avoiding profiling floats to measure ocean optics and phytoplankton characteristics continuously through two annual cycles in Baffin Bay, an Arctic sea that is covered by ice for 7 months a year. We demonstrate that net phytoplankton growth occurred even under 100% ice cover as early as February and that it resulted at least partly from photosynthesis. This highlights the adaptation of Arctic phytoplankton to extreme low-light conditions, which may be key to their survival before seeding the spring bloom.
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Affiliation(s)
- Achim Randelhoff
- Takuvik Joint International Laboratory, Université Laval (QC, Canada) and CNRS (France).
- Département de biologie, Université Laval and Québec-Océan, QC, Canada
| | - Léo Lacour
- Takuvik Joint International Laboratory, Université Laval (QC, Canada) and CNRS (France)
- Département de biologie, Université Laval and Québec-Océan, QC, Canada
| | - Claudie Marec
- Takuvik Joint International Laboratory, Université Laval (QC, Canada) and CNRS (France)
- Institut Universitaire Européen de la Mer, 29280 Plouzané, France
| | - Edouard Leymarie
- Sorbonne Université, CNRS, Laboratoire d'Océanographie de Villefranche (LOV), 06230 Villefranche-sur-Mer, France
| | - José Lagunas
- Takuvik Joint International Laboratory, Université Laval (QC, Canada) and CNRS (France)
- Département de biologie, Université Laval and Québec-Océan, QC, Canada
| | - Xiaogang Xing
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Gérald Darnis
- Takuvik Joint International Laboratory, Université Laval (QC, Canada) and CNRS (France)
- Département de biologie, Université Laval and Québec-Océan, QC, Canada
| | - Christophe Penkerc'h
- Sorbonne Université, CNRS, Laboratoire d'Océanographie de Villefranche (LOV), 06230 Villefranche-sur-Mer, France
| | - Makoto Sampei
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan
| | - Louis Fortier
- Takuvik Joint International Laboratory, Université Laval (QC, Canada) and CNRS (France)
- Département de biologie, Université Laval and Québec-Océan, QC, Canada
| | - Fabrizio D'Ortenzio
- Sorbonne Université, CNRS, Laboratoire d'Océanographie de Villefranche (LOV), 06230 Villefranche-sur-Mer, France
| | - Hervé Claustre
- Sorbonne Université, CNRS, Laboratoire d'Océanographie de Villefranche (LOV), 06230 Villefranche-sur-Mer, France
| | - Marcel Babin
- Takuvik Joint International Laboratory, Université Laval (QC, Canada) and CNRS (France)
- Département de biologie, Université Laval and Québec-Océan, QC, Canada
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15
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Mapping the Bathymetry of Melt Ponds on Arctic Sea Ice Using Hyperspectral Imagery. REMOTE SENSING 2020. [DOI: 10.3390/rs12162623] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hyperspectral remote-sensing instruments on unmanned aerial vehicles (UAVs), aircraft and satellites offer new opportunities for sea ice observations. We present the first study using airborne hyperspectral imagery of Arctic sea ice and evaluate two atmospheric correction approaches (ATCOR-4 (Atmospheric and Topographic Correction version 4; v7.0.0) and empirical line calibration). We apply an existing, field data-based model to derive the depth of melt ponds, to airborne hyperspectral AisaEAGLE imagery and validate results with in situ measurements. ATCOR-4 results roughly match the shape of field spectra but overestimate reflectance resulting in high root-mean-square error (RMSE) (between 0.08 and 0.16). Noisy reflectance spectra may be attributed to the low flight altitude of 200 ft and Arctic atmospheric conditions. Empirical line calibration resulted in smooth, accurate spectra (RMSE < 0.05) that enabled the assessment of melt pond bathymetry. Measured and modeled pond bathymetry are highly correlated (r = 0.86) and accurate (RMSE = 4.04 cm), and the model explains a large portion of the variability (R2 = 0.74). We conclude that an accurate assessment of melt pond bathymetry using airborne hyperspectral data is possible subject to accurate atmospheric correction. Furthermore, we see the necessity to improve existing approaches with Arctic-specific atmospheric profiles and aerosol models and/or by using multiple reference targets on the ground.
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16
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Matthes LC, Mundy CJ, L.-Girard S, Babin M, Verin G, Ehn JK. Spatial Heterogeneity as a Key Variable Influencing Spring-Summer Progression in UVR and PAR Transmission Through Arctic Sea Ice. FRONTIERS IN MARINE SCIENCE 2020; 7. [PMID: 0 DOI: 10.3389/fmars.2020.00183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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17
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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] [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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18
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Yan D, Endo H, Suzuki K. Increased temperature benefits growth and photosynthetic performance of the sea ice diatom Nitzschia cf. neglecta (Bacillariophyceae) isolated from saroma lagoon, Hokkaido, Japan. JOURNAL OF PHYCOLOGY 2019; 55:700-713. [PMID: 30802945 DOI: 10.1111/jpy.12846] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
During ice melt in spring, ice algae are released from the ice and could be exposed to variable temperatures and irradiances in surface water. Saroma Lagoon is an embayment with two inlets leading to the Sea of Okhotsk. With seasonal development of sea ice, its water temperature changes dramatically throughout the year. To investigate the living and photoprotective strategies of ice algae in such a coastal water system, we grew Nitzschia cf. neglecta, an ice diatom isolated from the sea ice of this lagoon, under irradiance levels of 30 and 100 μmol photons · m-2 · s-1 , and temperatures of 2°C and 10°C. Then the acclimated cells were exposed to high light in order to investigate the plasticity of their photosynthetic apparatus. At 10°C, cells grew faster and showed decreased susceptibility to high light. At 2°C, an immediate decrease in all pigment content upon exposure, as well as a higher cellular content of diatoxanthin was used to compensate for the more severe excitation stress. Highly efficient photoprotection was achieved through the diadinoxanthin-diatoxanthin cycle-dependent nonphotochemical quenching. While regulation through psbA and rbcL at the transcription level played a minor role in the response to high light stress at both temperatures. The wide tolerance to both temperature and light changes suggest that the thinning of sea ice and higher temperatures in a warmer world will lead to more intense blooms in Saroma Lagoon.
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Affiliation(s)
- Dong Yan
- Graduate School of Environmental Science, Hokkaido University, North 10 West 5, Kita-ku, Sapporo, 060-0810, Japan
| | - Hisashi Endo
- Faculty of Environmental Earth Science, Hokkaido University, North 10 West 5, Kita-ku, Sapporo, 060-0810, Japan
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Koji Suzuki
- Graduate School of Environmental Science, Hokkaido University, North 10 West 5, Kita-ku, Sapporo, 060-0810, Japan
- Faculty of Environmental Earth Science, Hokkaido University, North 10 West 5, Kita-ku, Sapporo, 060-0810, Japan
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Tedesco L, Vichi M, Scoccimarro E. Sea-ice algal phenology in a warmer Arctic. SCIENCE ADVANCES 2019; 5:eaav4830. [PMID: 31086818 PMCID: PMC6506242 DOI: 10.1126/sciadv.aav4830] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 04/01/2019] [Indexed: 05/05/2023]
Abstract
The Arctic sea-ice decline is among the most emblematic manifestations of climate change and is occurring before we understand its ecological consequences. We investigated future changes in algal productivity combining a biogeochemical model for sympagic algae with sea-ice drivers from an ensemble of 18 CMIP5 climate models. Model projections indicate quasi-linear physical changes along latitudes but markedly nonlinear response of sympagic algae, with distinct latitudinal patterns. While snow cover thinning explains the advancement of algal blooms below 66°N, narrowing of the biological time windows yields small changes in the 66°N to 74°N band, and shifting of the ice seasons toward more favorable photoperiods drives the increase in algal production above 74°N. These diverse latitudinal responses indicate that the impact of declining sea ice on Arctic sympagic production is both large and complex, with consequent trophic and phenological cascades expected in the rest of the food web.
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Affiliation(s)
- L. Tedesco
- Marine Research Centre, Finnish Environment Institute, Helsinki 00790, Finland
- Corresponding author.
| | - M. Vichi
- Department of Oceanography and Marine Research Institute, University of Cape Town, Rondebosch 7701, South Africa
| | - E. Scoccimarro
- Fondazione Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC), Bologna 40128, Italy
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20
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Rapid increase in atmospheric iodine levels in the North Atlantic since the mid-20th century. Nat Commun 2018; 9:1452. [PMID: 29654319 PMCID: PMC5899151 DOI: 10.1038/s41467-018-03756-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 03/09/2018] [Indexed: 11/09/2022] Open
Abstract
Atmospheric iodine causes tropospheric ozone depletion and aerosol formation, both of which have significant climate impacts, and is an essential dietary element for humans. However, the evolution of atmospheric iodine levels at decadal and centennial scales is unknown. Here, we report iodine concentrations in the RECAP ice-core (coastal East Greenland) to investigate how atmospheric iodine levels in the North Atlantic have evolved over the past 260 years (1750-2011), this being the longest record of atmospheric iodine in the Northern Hemisphere. The levels of iodine tripled from 1950 to 2010. Our results suggest that this increase is driven by anthropogenic ozone pollution and enhanced sub-ice phytoplankton production associated with the recent thinning of Arctic sea ice. Increasing atmospheric iodine has accelerated ozone loss and has considerably enhanced iodine transport and deposition to the Northern Hemisphere continents. Future climate and anthropogenic forcing may continue to amplify oceanic iodine emissions with potentially significant health and environmental impacts at global scale.
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Langbehn TJ, Varpe Ø. Sea-ice loss boosts visual search: fish foraging and changing pelagic interactions in polar oceans. GLOBAL CHANGE BIOLOGY 2017; 23:5318-5330. [PMID: 28657128 DOI: 10.1111/gcb.13797] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 06/02/2017] [Indexed: 06/07/2023]
Abstract
Light is a central driver of biological processes and systems. Receding sea ice changes the lightscape of high-latitude oceans and more light will penetrate into the sea. This affects bottom-up control through primary productivity and top-down control through vision-based foraging. We model effects of sea-ice shading on visual search to develop a mechanistic understanding of how climate-driven sea-ice retreat affects predator-prey interactions. We adapt a prey encounter model for ice-covered waters, where prey-detection performance of planktivorous fish depends on the light cycle. We use hindcast sea-ice concentrations (past 35 years) and compare with a future no-ice scenario to project visual range along two south-north transects with different sea-ice distributions and seasonality, one through the Bering Sea and one through the Barents Sea. The transect approach captures the transition from sub-Arctic to Arctic ecosystems and allows for comparison of latitudinal differences between longitudes. We find that past sea-ice retreat has increased visual search at a rate of 2.7% to 4.2% per decade from the long-term mean; and for high latitudes, we predict a 16-fold increase in clearance rate. Top-down control is therefore predicted to intensify. Ecological and evolutionary consequences for polar marine communities and energy flows would follow, possibly also as tipping points and regime shifts. We expect species distributions to track the receding ice-edge, and in particular expect species with large migratory capacity to make foraging forays into high-latitude oceans. However, the extreme seasonality in photoperiod of high-latitude oceans may counteract such shifts and rather act as a zoogeographical filter limiting poleward range expansion. The provided mechanistic insights are relevant for pelagic ecosystems globally, including lakes where shifted distributions are seldom possible but where predator-prey consequences would be much related. As part of the discussion on photoperiodic implications for high-latitude range shifts, we provide a short review of studies linking physical drivers to latitudinal extent.
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Affiliation(s)
- Tom J Langbehn
- Department of Biology, University of Bergen, Bergen, Norway
- University Centre in Svalbard, Longyearbyen, Norway
| | - Øystein Varpe
- University Centre in Svalbard, Longyearbyen, Norway
- Akvaplan-niva, Fram Centre, Tromsø, Norway
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