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Gómez Coutouly, Yan Axel. (2022). Le premier peuplement préhistorique de l’Amérique : un débat idéologique ?.
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Fillion D., Dominé F., Couture R.M. (2022). Shedding Light on a Dark Lake: How the Sun Transforms the Chemistry of Lakes.
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Federica Pirri, Lino Ometto, Silvia Fuselli, Flávia A. N. Fernandes, Lorena Ancona, Nunzio Perta, Daniele Di Marino, Céline Le Bohec, Lorenzo Zane, Emiliano Trucchi. (2022). Selection-driven adaptation to the extreme Antarctic environment in the Emperor penguin (Vol. 129).
Abstract: The eco-evolutionary history of penguins is characterised by shifting from temperate to cold environments. Breeding in Antarctica, the Emperor penguin appears as an extreme outcome of this process, with unique features related to insulation, heat production and energy management. However, whether this species actually diverged from a less cold-adapted ancestor, more ecologically similar to its sister species, the King penguin, is still an open question. As the Antarctic colonisation likely resulted in vast changes in selective pressure experienced by the Emperor penguin, the relative quantification of the genomic signatures of selection, unique to each sister species, could answer this question. Applying phylogeny-based selection tests on 7651 orthologous genes, we identified a more pervasive selection shift in the Emperor penguin than in the King penguin, supporting the hypothesis that its extreme cold adaptation is a derived state. Furthermore, among candidate genes under selection, four (TRPM8, LEPR, CRB1, and SFI1) were identified before in other cold-adapted homeotherms, like the woolly Mammoth, while other 161 genes can be assigned to biological functions relevant to cold adaptation identified in previous studies. Location and structural effects of TRPM8 substitutions in Emperor and King penguin lineages support their functional role with putative divergent effects on thermal adaptation. We conclude that extreme cold adaptation in the Emperor penguin largely involved unique genetic options which, however, affect metabolic and physiological traits common to other cold-adapted homeotherms.
Keywords: Adaptation, Physiological Animals Antarctic Regions Genome Phylogeny Spheniscidae
Programme: 137
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Clara Leistenschneider, Céline Le Bohec, Olaf Eisen, Aymeric Houstin, Simon Neff, Sebastian Primpke, Daniel P. Zitterbart, Patricia Burkhardt-Holm, Gunnar Gerdts. (2022). No evidence of microplastic ingestion in emperor penguin chicks (Aptenodytes forsteri) from the Atka Bay colony (Dronning Maud Land, Antarctica) (Vol. 851).
Abstract: Microplastic (<5 mm; MP) pollution has been an emerging threat for marine ecosystems around the globe with increasing evidence that even the world's most remote areas, including Antarctica, are no longer unaffected. Few studies however, have examined MP in Antarctic biota, and especially those from Antarctic regions with low human activity, meaning little is known about the extent to which biota are affected. The aim of this study was to investigate, for the first time, the occurrence of MP in the emperor penguin (Aptenodytes forsteri), the only penguin species breeding around Antarctica during the austral winter, and an endemic apex predator in the Southern Ocean. To assess MP ingestion, the gizzards of 41 emperor penguin chicks from Atka Bay colony (Dronning Maud Land, Antarctica), were dissected and analyzed for MP >500 μm using Attenuated Total Reflection Fourier-transform Infrared (ATR-FTIR) spectroscopy. A total of 85 putative particles, mostly in the shape of fibers (65.9 %), were sorted. However, none of the particles were identified as MP applying state-of-the-art methodology. Sorted fibers were further evidenced to originate from contamination during sample processing and analyses. We find that MP concentrations in the local food web of the Weddell Sea and Dronning Maud Land coastal and marginal sea-ice regions; the feeding grounds to chick-rearing emperor penguin adults, are currently at such low levels that no detectable biomagnification is occurring via trophic transfer. Being in contrast to MP studies on other Antarctic and sub-Antarctic penguin species, our comparative discussion including these studies, highlights the importance for standardized procedures for sampling, sample processing and analyses to obtain comparable results. We further discuss other stomach contents and their potential role for MP detection, as well as providing a baseline for the long-term monitoring of MP in apex predator species from this region.
Keywords: Antarctica ATR-FTIR Microplastics Stomach content Weddell Sea & Dronning Maud Land
Programme: 137
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Aymeric Houstin, Daniel P. Zitterbart, Karine Heerah, Olaf Eisen, Víctor Planas-Bielsa, Ben Fabry, Céline Le Bohec. (2022). Juvenile emperor penguin range calls for extended conservation measures in the Southern Ocean (Vol. 9).
Abstract: To protect the unique and rich biodiversity of the Southern Ocean, conservation measures such as marine protected areas (MPAs) have been implemented. Currently, the establishment of several additional protection zones is being considered based on the known habitat distributions of key species of the ecosystems including emperor penguins and other marine top predators. However, the distribution of such species at sea is often insufficiently sampled. Specifically, current distribution models focus on the habitat range of adult animals and neglect that immatures and juveniles can inhabit different areas. By tracking eight juvenile emperor penguins in the Weddell Sea over 1 year and performing a meta-analysis including previously known data from other colonies, we show that conservation efforts in the Southern Ocean are insufficient for protecting this highly mobile species, and particularly its juveniles. We find that juveniles spend approximately 90% of their time outside the boundaries of proposed and existing MPAs, and that their distribution extends beyond (greater than 1500 km) the species' extent of occurrence as defined by the International Union for Conservation of Nature. Our data exemplify that strategic conservation plans for the emperor penguin and other long-lived ecologically important species should consider the dynamic habitat range of all age classes.
Keywords: conservation biology early life MPA network polar regions seabirds
Programme: 137
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Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Luke Gregor, Judith Hauck, Corinne Le Quéré, Ingrid T. Luijkx, Are Olsen, Glen P. Peters, Wouter Peters, Julia Pongratz, Clemens Schwingshackl, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone R. Alin, Ramdane Alkama, Almut Arneth, Vivek K. Arora, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Henry C. Bittig, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Wiley Evans, Stefanie Falk, Richard A. Feely, Thomas Gasser, Marion Gehlen, Thanos Gkritzalis, Lucas Gloege, Giacomo Grassi, Nicolas Gruber, Özgür Gürses, Ian Harris, Matthew Hefner, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Atul K. Jain, Annika Jersild, Koji Kadono, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Peter Landschützer, Nathalie Lefèvre, Keith Lindsay, Junjie Liu, Zhu Liu, Gregg Marland, Nicolas Mayot, Matthew J. McGrath, Nicolas Metzl, Natalie M. Monacci, David R. Munro, Shin-Ichiro Nakaoka, Yosuke Niwa, Kevin O'Brien, Tsuneo Ono, Paul I. Palmer, Naiqing Pan, Denis Pierrot, Katie Pocock, Benjamin Poulter, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Carmen Rodriguez, Thais M. Rosan, Jörg Schwinger, Roland Séférian, Jamie D. Shutler, Ingunn Skjelvan, Tobias Steinhoff, Qing Sun, Adrienne J. Sutton, Colm Sweeney, Shintaro Takao, Toste Tanhua, Pieter P. Tans, Xiangjun Tian, Hanqin Tian, Bronte Tilbrook, Hiroyuki Tsujino, Francesco Tubiello, Guido R. van der Werf, Anthony P. Walker, Rik Wanninkhof, Chris Whitehead, Anna Willstrand Wranne, Rebecca Wright, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, Jiye Zeng, Bo Zheng. (2022). Global Carbon Budget 2022 (Vol. 14).
Abstract: Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2021, EFOS increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr−1 (9.9 ± 0.5 GtC yr−1 when the cement carbonation sink is included), and ELUC was 1.1 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr−1 (40.0 ± 2.9 GtCO2). Also, for 2021, GATM was 5.2 ± 0.2 GtC yr−1 (2.5 ± 0.1 ppm yr−1), SOCEAN was 2.9 ± 0.4 GtC yr−1, and SLAND was 3.5 ± 0.9 GtC yr−1, with a BIM of −0.6 GtC yr−1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71 ± 0.1 ppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0 % (0.1 % to 1.9 %) globally and atmospheric CO2 concentration reaching 417.2 ppm, more than 50 % above pre-industrial levels (around 278 ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2021, but discrepancies of up to 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at https://doi.org/10.18160/GCP-2022 (Friedlingstein et al., 2022b).
Programme: 416
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Aymeric Houstin, Daniel P. Zitterbart, Alexander Winterl, Sebastian Richter, Víctor Planas-Bielsa, Damien Chevallier, André Ancel, Jérôme Fournier, Ben Fabry, Céline Le Bohec. (2022). Biologging of emperor penguins—Attachment techniques and associated deployment performance (Vol. 17).
Abstract: An increasing number of marine animals are equipped with biologgers, to study their physiology, behaviour and ecology, often for conservation purposes. To minimise the impacts of biologgers on the animals’ welfare, the Refinement principle from the Three Rs framework (Replacement, Reduction, Refinement) urges to continuously test and evaluate new and updated biologging protocols. Here, we propose alternative and promising techniques for emperor penguin (Aptenodytes forsteri) capture and on-site logger deployment that aim to mitigate the potential negative impacts of logger deployment on these birds. We equipped adult emperor penguins for short-term (GPS, Time-Depth Recorder (TDR)) and long-term (i.e. planned for one year) deployments (ARGOS platforms, TDR), as well as juvenile emperor penguins for long-term deployments (ARGOS platforms) in the Weddell Sea area where they had not yet been studied. We describe and qualitatively evaluate our protocols for the attachment of biologgers on-site at the colony, the capture of the animals and the recovery of the devices after deployment. We report unprecedented recaptures of long-term equipped adult emperor penguins (50% of equipped individuals recaptured after 290 days). Our data demonstrate that the traditional technique of long-term attachment by gluing the biologgers directly to the back feathers causes excessive feather breakage and the loss of the devices after a few months. We therefore propose an alternative method of attachment for back-mounted devices. This technique led to successful year-round deployments on 37.5% of the equipped juveniles. Finally, we also disclose the first deployments of leg-bracelet mounted TDRs on emperor penguins. Our findings highlight the importance of monitoring potential impacts of biologger deployments on the animals and the need to continue to improve methods to minimize disturbance and enhance performance and results.
Keywords: Animal behavior Animal sociality Birds Equipment Feathers Legs Molting Penguins
Programme: 137
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Héloïg Barbel Le Page, Dominique Todisco, James Woollett. (2022). (Re)penser la relation au territoire : vers une archéologie de l’habiter.
Abstract: La posture endossée par les chercheur.es structure les problématiques qu’il.elle.s abordent et leurs choix quant aux approches employées pour les étudier. Cet article offre une réflexion sur l’importance de questionner nos postures paradigmatiques, qui structurent notre rapport à la recherche. Elle a émergé de recherches menées en collaboration avec le Gouvernement du Nunatsiavut et la communauté de Nain (Nunatsiavut, Labrador, Canada). Celles-ci contribuent à pluraliser les narrations historiques sur la période coloniale, en s’intéressant à la diversité des choix des Nunatsiavummiut concernant leurs relations avec le système missionnaire. Cette discussion, articulant archéologie et géographie, développe une approche relationnelle du territoire par l’habiter et questionne la trace laissée par les systèmes d’activités quotidiennes à travers le temps et l’espace. Une réflexion sur les façons d’appréhender la complexité des relations aux lieux, au paysage et aux artefacts nous amène à aborder la diversité des vestiges mis au jour, et la nécessité d’une mise en dialogue des disciplines pour étudier les systèmes d’activités passés à partir de leurs traces.
Programme: 1080
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Eleonora Fossile. (2022). Ice-related environmental changes in Arctic fjords : new insights from benthic foraminifera.
Abstract: Le changement climatique menace les régions polaires avec des conséquences majeures sur la dynamique des glaces et les écosystèmes associés. Les simulations de fonte glaciaire reposent sur des reconstitutions paléo environnementales, qui complètent les mesures directes sur la période actuelle pour réduire l'incertitude des prévisions. Des proxies basés sur l’écologie des foraminifères benthiques (FB) sont développés dans cette thèse pour suivre la dynamique des glaces de mer et le retrait des glaciers côtiers. Dans le Storfjorden, les FB montrent une réponse aux eaux enrichies en CO2 (saumures) libérées pendant les processus de formation de glace de mer. Le rapport entre les FB agglutinés et calcaires (A/C) est proposé comme proxy de la persistance sur les fonds de ces saumures qui provoquent la dissolution des tests calcaires des FB. Bien que le signal A/C soit affecté par des processus taphonomiques, il permet de souligner les différences entre les zones affectées par la persistance de saumures et celles sous influence intermittente. Dans le Kongsfjorden, des gradients environnementaux abrupts (e.g., salinité, turbidité de l'eau, flux organiques) sont provoqués par la dynamique des glaciers côtiers. En été, différents assemblages de FB s’installent en fonction de l’éloignement au front du glacier, avec une augmentation vers le large de la diversité taxonomique et fonctionnelle. Un indicateur combinant plusieurs mesures de diversité a été proposé comme proxy du recul des glaciers côtiers, et son efficacité a été testée sur une archive sédimentaire des 60 dernières années. Les deux proxies proposés ici sont donc applicables dans tout environnement arctique similaire.
Keywords: 550 Bioindicateurs Bioindicators Glace de mer Glacier côtier Indicateurs biologiques Polynie Polynya Proxy Sea ice Svalbard Tidewater glacier
Programme: 1223
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Tranchant Y.-T. (2022). Vers une meilleure exploitation de l’altimétrie côtière : apports combinés de la modélisation hydrodynamique à haute-résolution et des nouvelles techniques de cartographie du niveau marin par GNSS /// Towards a better use of coastal altimetry : contributions of hydrodynamic modelling and new GNSS techniques.
Abstract: La mesure du niveau de la mer par satellite a atteint un niveau sans précédent en termes de précision et de couverture spatio-temporelle. Ces observations nous ont permis d'améliorer notre compréhension de la dynamique à grande échelle des océans, mais leur exploitation reste un défi à l’approche de la côte, où les incertitudes liées à la marée océanique et aux fines échelles du géoïde sont plus importantes. L’objectif de cette thèse est de développer de nouvelles méthodologies s’appuyant sur les mesures mobiles du niveau de la mer par GNSS et la modélisation hydrodynamique afin de mieux exploiter les mesures altimétriques côtière et de préparer l’arrivée des futures missions. Lors d’une campagne menée avec le drone marin PAMELi en Juillet 2020 dans les Pertuis Charentais, une cartographie du niveau marin est réalisée le long d’un itinéraire préprogrammé. Cette cartographie est exploitée afin d’évaluer un modèle de marée sous une trace altimétrique, et démontrer le potentiel d’un drone pour étendre spatialement nos capacités de validation. Par la suite, on estime les pentes de géoïde dans la zone à partir du même jeu de données, en combinant mesures in-situ et modèle hydrodynamique. On montre que la modélisation des gradients de topographie dynamique permet d’améliorer la précision de la cartographie des pentes de géoïde. Ces deux études exploitent une méthodologie basée sur les différences aux points de croisement, et offrent des perspectives sur l'utilisation des drones marins dans le contexte de la future mission SWOT. Enfin, on présente une méthode de prédiction du trait de côte basée sur l’utilisation d’un MNT et du modèle hydrodynamique, appliquée aux passage Sentinel-3A afin d’évaluer l’impact des bancs découvrant sur la mesure altimétrique. Dans leur ensemble, ces travaux constituent un socle méthodologique qui permettra de mieux comprendre et utiliser les mesures altimétriques dans les environnements côtiers, et préparer l’arrivée de la future mission SWOT.
Keywords: Altimétrie côtière Coastal altimetry Drone marin Drones -- Mer GNSS Hydrodynamic modelling Littoraux -- France Localisation par satellites, Systèmes de Marine drone Mer -- Niveau -- Mesure Modélisation hydrodynamique
Programme: 688
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