Jean Roger, Bernard Pelletier, Maxime Duphil, Jérôme Lefèvre, Jérôme Aucan, Pierre Lebellegard, Bruce Thomas, Céline Bachelier, David Varillon. (2021). The Mw 7.5 Tadine (Maré, Loyalty Is.) earthquake and related tsunami of December 5, 2018: implications for tsunami hazard assessment in New Caledonia.
Abstract: On The 5th Of December 2018, A Magnitude Mw 7.5 Earthquake Occurred Southeast Of Maré, An Island Of The Loyalty Archipelago, New Caledonia. This Earthquake Is Located At The Junction Between The Plunging Loyalty Ridge And The Southernmost Vanuatu Arc, In A Tectonically Very Active Area Regularly Subjected To Strong Seismic Crises And Events Higher Than Magnitude 7 And Up To 8. Widely Felt In New Caledonia It Has Been Immediately Followed By A Tsunami Warning, Confirmed Shortly After By A First Wave Arrival At The Loyalty Islands Tide Gauges (Maré And Lifou), Then Along The East Coast Of Grande Terre Of New Caledonia And In Several Islands Of The Vanuatu Archipelago. Seafloor Initial Deformation Linked To Tsunami Generation Has Been Modeled With Most Numerical Code Using Earthquake Parameters Available From Seismic Observatories. Then The Wave Propagation Has Been Modeled Using Schism, Another Modelling Code Solving The Shallow Water Equations On An Unstructured Grid Based On A New Regional Dem Of ~180 M Resolution And Allowing Refinement In Many Critical Areas. Finally, The Results Have Been Compared To Tide Gauge Records, Field Observations And Testimonials From 2018. The Arrival Times, Wave Amplitude And Polarities Present Good Similarities, Especially In Far-field Locations (Hienghène, Port-vila And Poindimié). Maximum Wave Heights And Energy Maps For Two Different Scenarios Highlight The Fact That The Orientation Of The Source (Strike Of The Rupture) Played An Important Role, Focusing The Maximum Energy Path Of The Tsunami South Of Grande-terre And The Isle Of Pines. However, Both Scenarios Indicate Similar Propagation Toward Aneityum, Vanuatu Southernmost Island, The Bathymetry Acting Like A Waveguide. This Study Has A Significant Implication In Tsunami Hazard Mitigation In New Caledonia As It Helps To Validate The Modelling Code And Process Used To Prepare A Scenarios Database For Warning And Coastal Evacuation.
Programme: 133
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Alberto Baudena, Enrico Ser-Giacomi, Donatella D’Onofrio, Xavier Capet, Cedric Cotté, Yves Cherel, Francesco D’Ovidio. (2021). Fine-scale structures as spots of increased fish concentration in the open ocean (Vol. 11).
Abstract: Oceanic frontal zones have been shown to deeply influence the distribution of primary producers and, at the other extreme of the trophic web, top predators. However, the relationship between these structures and intermediate trophic levels is much more obscure. In this paper we address this knowledge gap by comparing acoustic measurements of mesopelagic fish concentrations to satellite-derived fine-scale Lagrangian Coherent Structures in the Indian sector of the Southern Ocean. First, we demonstrate that higher fish concentrations occur more frequently in correspondence with strong Lagrangian Coherent Structures. Secondly, we illustrate that, while increased fish densities are more likely to be observed over these structures, the presence of a fine-scale feature does not imply a concomitant fish accumulation, as other factors affect fish distribution. Thirdly, we show that, when only chlorophyll-rich waters are considered, front intensity modulates significantly more the local fish concentration. Finally, we discuss a model representing fish movement along Lagrangian features, specifically built for mid-trophic levels. Its results, obtained with realistic parameters, are qualitatively consistent with the observations and the spatio-temporal scales analysed. Overall, these findings may help to integrate intermediate trophic levels in trophic models, which can ultimately support management and conservation policies.
Keywords: Fisheries Marine biology Physical oceanography
Programme: 109
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Daniel C. Jones, Filipe R. Ceia, Eugene Murphy, Karine Delord, Robert W. Furness, Ariane Verdy, Matthew Mazloff, Richard A. Phillips, Paul M. Sagar, Jean-Baptiste Sallée, Ben Schreiber, David R. Thompson, Leigh G. Torres, Philip J. Underwood, Henri Weimerskirch, José C. Xavier. (2021). Untangling local and remote influences in two major petrel habitats in the oligotrophic Southern Ocean (Vol. 27).
Abstract: Ocean circulation connects geographically distinct ecosystems across a wide range of spatial and temporal scales via exchanges of physical and biogeochemical properties. Remote oceanographic processes can be especially important for ecosystems in the Southern Ocean, where the Antarctic Circumpolar Current transports properties across ocean basins through both advection and mixing. Recent tracking studies have indicated the existence of two large-scale, open ocean habitats in the Southern Ocean used by grey petrels (Procellaria cinerea) from two populations (i.e., Kerguelen and Antipodes islands) during their nonbreeding season for extended periods during austral summer (i.e., October to February). In this work, we use a novel combination of large-scale oceanographic observations, surface drifter data, satellite-derived primary productivity, numerical adjoint sensitivity experiments, and output from a biogeochemical state estimate to examine local and remote influences on these grey petrel habitats. Our aim is to understand the oceanographic features that control these isolated foraging areas and to evaluate their ecological value as oligotrophic open ocean habitats. We estimate the minimum local primary productivity required to support these populations to be much <1% of the estimated local primary productivity. The region in the southeast Indian Ocean used by the birds from Kerguelen is connected by circulation to the productive Kerguelen shelf. In contrast, the region in the south-central Pacific Ocean used by seabirds from the Antipodes is relatively isolated suggesting it is more influenced by local factors or the cumulative effects of many seasonal cycles. This work exemplifies the potential use of predator distributions and oceanographic data to highlight areas of the open ocean that may be more dynamic and productive than previously thought. Our results highlight the need to consider advective connections between ecosystems in the Southern Ocean and to re-evaluate the ecological relevance of oligotrophic Southern Ocean regions from a conservation perspective.
Keywords: Antarctic Circumpolar Current (ACC) biogeography conservation grey petrels high seas hotspot open ocean primary productivity Procellaria cinerea seabirds
Programme: 109
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Christophe Leroy-Dos Santos, Mathieu Casado, Frédéric Prié, Olivier Jossoud, Erik Kerstel, Morgane Farradèche, Samir Kassi, Elise Fourré, Amaëlle Landais. (2021). A dedicated robust instrument for water vapor generation at low humidity for use with a laser water isotope analyzer in cold and dry polar regions (Vol. 14). Bachelor's thesis, , .
Abstract: Obtaining Precise Continuous Measurements Of Water Vapor Isotopic Composition In Dry Places (Polar Or High-altitude Regions) Is An Important Challenge. The Current Limitation Is The Strong Influence Of Humidity On The Measured Water Isotopic Composition By Laser Spectroscopy Instruments For Low Humidity Levels (Below 3000 Ppmv). This Problem Is Addressed By Determining The Relationships Between Humidity And Measured δ18o And δD Of Known Water Standards. Here, We Present The Development Of A Robust Field Instrument Able To Generate Water Vapor, Down To 70 Ppmv, At Very Stable Humidity Levels (Average 1σ Lower Than 10 Ppmv). This Instrument, Operated By A Raspberry Interface, Can Be Coupled To A Commercial Laser Spectroscopy Instrument. We Checked The Stability Of The System As Well As Its Accuracy When Expressing The Measured Isotopic Composition Of Water Vapor On The Vsmow–slap (Vienna Standard Mean Ocean Water – Standard Light Antarctic Precipitation) Scale. It Proved To Be Highly Stable During Autonomous Operation Over More Than 1 Year At The East Antarctic Concordia And Dumont D'urville Stations.
Programme: 1110,1169,1205
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Matthias Macé, Camille Richeval, Liubomira Romanova, Patrice Gérard, Sylvie Duchesne, Catherine Cannet, Irina Boyarskikh, Annie Gérault, Vincent Zvénigorosky, Darya Nikolaeva, Charles Stepanoff, Delphine Allorge, Michele Debrenne, Bertrand Ludes, Anatoly Alexeev, Jean-Michel Gaulier, Eric Crubézy. (2021). Impact of socio-economic traditions on current tobacco and tea addictions (Siberia 17th to 20th century).
Abstract: Objective To investigate how tobacco and tea spread among virgin populations and how the first addictions have subsequently influenced the behavior of present-day populations. Design Retrospective observational study using data from frozen burials and levels of theobromine, theophylline, caffeine, nicotine, and cotinine measured in hair samples from frozen bodies of autochthonous people. Confrontation of the results with new ethnobotanical, historical and cultural data from the past and with present day epidemiological data from the same region. Setting Eastern Siberia (Yakutia) from the contact with Europeans (17th century) to the assimilation of people into Russian society (19th century). Participants 47 frozen bodies of autochthonous people from eastern Siberia and a review of present-day populations from Yakutia Intervention Levels of theobromine, theophylline, caffeine, nicotine, and cotinine were measured in hair samples. Along with the collection of cultural data associated with the bodies, potential comorbidities were investigated. Main outcome measure We combined LC-HRMS and LC-MS/MS tools for toxicological investigations in hair and we assessed the association between xenobiotic concentrations and geography using several permutation-based methods to infer the economic circuits of tobacco and tea. Comparison of the results obtained with ethno-botanical analyses allowed to identify the products from which the metabolites were derived. Results Hair levels of theobromine, theophylline and caffeine vary with the type of beverage consumed: green, black or local herbal teas. At the beginning of our study period, a few heavy consumers of tobacco were found among light or passive consumers. Tobacco-related co-morbidities began to be recorded one century after contact with Europeans. Heavy tea users were only found from the 19th century and the heaviest users of the two substances date from this century. After the first contact, teas were widely consumed as beverages and medicines but also for shamanic reasons. Economic factors, fashion and social and family contacts seem to have played a decisive role in tobacco consumption very early on. Conclusion Epidemiological characteristics of present-day Yakutia suggest that the high prevalence of smokers and tea consumers, the prevalence of female smokers and tobacco use in the north, find their origins in the diffusion phenomena of the 18th and 19th century. Behavioral evolution governed the process of substance integration and was determinant for the continuity of use of these substances over a long period of time.
Programme: 1038
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Ross N. Cuthbert, Zarah Pattison, Nigel G. Taylor, Laura Verbrugge, Christophe Diagne, Danish A. Ahmed, Boris Leroy, Elena Angulo, Elizabeta Briski, César Capinha, Jane A. Catford, Tatenda Dalu, Franz Essl, Rodolphe E. Gozlan, Phillip J. Haubrock, Melina Kourantidou, Andrew M. Kramer, David Renault, Ryan J. Wasserman, Franck Courchamp. (2021). Global economic costs of aquatic invasive alien species (Vol. 775).
Abstract: Much research effort has been invested in understanding ecological impacts of invasive alien species (IAS) across ecosystems and taxonomic groups, but empirical studies about economic effects lack synthesis. Using a comprehensive global database, we determine patterns and trends in economic costs of aquatic IAS by examining: (i) the distribution of these costs across taxa, geographic regions and cost types; (ii) the temporal dynamics of global costs; and (iii) knowledge gaps, especially compared to terrestrial IAS. Based on the costs recorded from the existing literature, the global cost of aquatic IAS conservatively summed to US$345 billion, with the majority attributed to invertebrates (62%), followed by vertebrates (28%), then plants (6%). The largest costs were reported in North America (48%) and Asia (13%), and were principally a result of resource damages (74%); only 6% of recorded costs were from management. The magnitude and number of reported costs were highest in the United States of America and for semi-aquatic taxa. Many countries and known aquatic alien species had no reported costs, especially in Africa and Asia. Accordingly, a network analysis revealed limited connectivity among countries, indicating disparate cost reporting. Aquatic IAS costs have increased in recent decades by several orders of magnitude, reaching at least US$23 billion in 2020. Costs are likely considerably underrepresented compared to terrestrial IAS; only 5% of reported costs were from aquatic species, despite 26% of known invaders being aquatic. Additionally, only 1% of aquatic invasion costs were from marine species. Costs of aquatic IAS are thus substantial, but likely underreported. Costs have increased over time and are expected to continue rising with future invasions. We urge increased and improved cost reporting by managers, practitioners and researchers to reduce knowledge gaps. Few costs are proactive investments; increased management spending is urgently needed to prevent and limit current and future aquatic IAS damages.
Keywords: Brackish Freshwater Habitat biases InvaCost Marine Monetary impact
Programme: 136
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Guillaume Schwob, Nicolás I. Segovia, Claudio González-Wevar, Léa Cabrol, Julieta Orlando, Elie Poulin. (2021). Exploring the Microdiversity Within Marine Bacterial Taxa: Toward an Integrated Biogeography in the Southern Ocean (Vol. 12).
Abstract: Most of the microbial biogeographic patterns in the oceans have been depicted at the whole community level, leaving out finer taxonomic resolution (i.e., microdiversity) that is crucial to conduct intra-population phylogeographic study, as commonly done for macroorganisms. Here, we present a new approach to unravel the bacterial phylogeographic patterns combining community-wide survey by 16S rRNA gene metabarcoding and intra-species resolution through the oligotyping method, allowing robust estimations of genetic and phylogeographic indices, and migration parameters. As a proof-of-concept, we focused on the bacterial genus Spirochaeta across three distant biogeographic provinces of the Southern Ocean; maritime Antarctica, sub-Antarctic Islands, and Patagonia. Each targeted Spirochaeta operational taxonomic units were characterized by a substantial intrapopulation microdiversity, and significant genetic differentiation and phylogeographic structure among the three provinces. Gene flow estimations among Spirochaeta populations support the role of the Antarctic Polar Front as a biogeographic barrier to bacterial dispersal between Antarctic and sub-Antarctic provinces. Conversely, the Antarctic Circumpolar Current appears as the main driver of gene flow, connecting sub-Antarctic Islands with Patagonia and maritime Antarctica. Additionally, historical processes (drift and dispersal limitation) govern up to 86% of the spatial turnover among Spirochaeta populations. Overall, our approach bridges the gap between microbial and macrobial ecology by revealing strong congruency with macroorganisms distribution patterns at the populational level, shaped by the same oceanographic structures and ecological processes.
Programme: 1044
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Carlo Cauzzi, Susana Custódio, Christos P. Evangelidis, Giovanni Lanzano, Lucia Luzi, Lars Ottemöller, Helle Pedersen, Reinoud Sleeman. (2021). Preface to the Focus Section on European Seismic Networks and Associated Services and Products (Vol. 92).
Abstract: Most of the articles of this focus section serve as good examples in the open science domain, in which data are expected to be “findable, accessible, interoperable, and reusable” (Wilkinson et al., 2016). In many contributions, emphasis is placed on quality: as automated access to seismological archives via standardized web services emerges as the preferred user strategy, ensuring the high quality of data and metadata becomes more and more important (e.g., Büyükakpınar et al., 2021; Cambaz et al., 2021; Carrilho et al., 2021; Evangelidis et al., 2021; Mader and Ritter, 2021; Ottemöller et al., 2021; Péquegnat et al., 2021; Stammler et al., 2021; Strollo et al., 2021). Quality is especially important at a time when very large datasets are increasingly being processed routinely and “blindly” in machine‐learning approaches. The vast majority of seismological data centers already manage multisensor archives (seismometers, accelerometers, infrasound, amphibian seismological instruments, high‐rate global navigation satellite systems, etc.), and the inclusion of new types of data (e.g., rotational sensors, low‐cost instrumentation, and synthetic waveforms) in seismological archives poses new challenges and prompts for new technical solutions and standards for data archiving, metadata preparation, quality checks, data dissemination, and processing. A particular challenge over the next few years (Quinteros, Carter, et al., 2021) is the upcoming massive growth of data volume, due in particular to new instruments (large‐N experiments and distributed acoustic sensing systems) but also to increased volumes of traditional seismic data. It is expected that multisensor experiments will progressively dominate the technical and scientific discussion in geosciences in the coming decade, spurred by the societal need to develop multidisciplinary, multihazard science and research products. Joining forces and competences is therefore key to addressing future challenges: the EarthScope Consortium was recently established in the United States, and the European Plate Observing System (EPOS) was created as the framework to integrate all geoscience services in the greater European region. ORFEUS and its seismic network community strongly support the development and consolidation of EPOS by participating in the activities of its thematic core service for seismology.
Programme: 133
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Nicolas Meyer, Loïc Bollache, Matthias Galipaud, Jérôme Moreau, François-Xavier Dechaume-Moncharmont, Eve Afonso, Anders Angerbjörn, Joël Bêty, Glen Brown, Dorothée Ehrich, Vladimir Gilg, Marie-Andrée Giroux, Jannik Hansen, Richard Lanctot, Johannes Lang, Christopher Latty, Nicolas Lecomte, Laura McKinnon, Lisa Kennedy, Jeroen Reneerkens, Sarah Saalfeld, Brigitte Sabard, Niels M. Schmidt, Benoît Sittler, Paul Smith, Aleksander Sokolov, Vasiliy Sokolov, Natalia Sokolova, Rob van Bemmelen, Øystein Varpe, Olivier Gilg. (2021). Behavioural responses of breeding arctic sandpipers to ground-surface temperature and primary productivity (Vol. 755).
Abstract: Most birds incubate their eggs, which requires time and energy at the expense of other activities. Birds generally have two incubation strategies: biparental where both mates cooperate in incubating eggs, and uniparental where a single parent incubates. In harsh and unpredictable environments, incubation is challenging due to high energetic demands and variable resource availability. We studied the relationships between the incubation behaviour of sandpipers (genus Calidris) and two environmental variables: temperature and a proxy of primary productivity (i.e. NDVI). We investigated how these relationships vary between incubation strategies and across species among strategies. We also studied how the relationship between current temperature and incubation behaviour varies with previous day's temperature. We monitored the incubation behaviour of nine sandpiper species using thermologgers at 15 arctic sites between 2016 and 2019. We also used thermologgers to record the ground surface temperature at conspecific nest sites and extracted NDVI values from a remote sensing product. We found no relationship between either environmental variables and biparental incubation behaviour. Conversely, as ground-surface temperature increased, uniparental species decreased total duration of recesses (TDR) and mean duration of recesses (MDR), but increased number of recesses (NR). Moreover, small species showed stronger relationships with ground-surface temperature than large species. When all uniparental species were combined, an increase in NDVI was correlated with higher mean duration, total duration and number of recesses, but relationships varied widely across species. Finally, some uniparental species showed a lag effect with a higher nest attentiveness after a warm day while more recesses occurred after a cold day than was predicted based on current temperatures. We demonstrate the complex interplay between shorebird incubation strategies, incubation behaviour, and environmental conditions. Understanding how species respond to changes in their environment during incubation helps predict their future reproductive success.
Keywords: Environmental conditions Incubation behaviour Incubation recesses Incubation strategy Lag effects NDVI Shorebird
Programme: 1036
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C. Albert, V. S. Bråthen, S. Descamps, T. Anker-Nilssen, A. Cherenkov, S. Christensen-Dalsgaard, J. Danielsen, K. E. Erikstad, M. Gavrilo, S. A. Hanssen, H. H. Helgason, J. E. Jónsson, Y. Kolbeinsson, Y. Krasnov, M. Langset, E. Lorentzen, B. Olsen, T. K. Reiertsen, H. Strøm, G. H. Systad, G. Tertitski, P. M. Thompson, T. L. Thórarinsson, P. Bustamante, B. Moe, J. Fort. (2021). Inter-annual variation in winter distribution affects individual seabird contamination with mercury (Vol. 676).
Abstract: Migratory seabirds are exposed to various pollutants throughout their annual cycle. Among them, mercury (Hg) is of particular concern given its large impact on animal health. Recent studies suggest that winter is a critical period for seabirds when contamination by Hg can be higher than at other times of year. However, individuals within and between species can have different migration strategies and winter distributions that could affect their exposure. Here, we combined multi-year individual tracking data and Hg measurements from 6 Arctic seabird species. We investigated whether inter-annual variations in individual winter contamination with Hg was related to seabird fidelity to a wintering site over years. First, our results show that Hg concentrations above the toxicity threshold (i.e. 5 µg g-1 dry weight in feathers) were observed in variable proportions according to species (from 2% of northern fulmars to 37% of Brünnich’s guillemots). Second, individuals with high fidelity to a wintering ground had more similar Hg concentrations among years compared to individuals with low fidelity, suggesting an effect of their migratory strategy on Hg contamination. Further, we found that the directional change in wintering areas among years influenced seabird Hg contamination, highlighting an additional effect of seabirds’ winter distribution. More specifically, individuals migrating to the northwest direction of a previous wintering ground tended to be more contaminated compared to those moving to eastern directions. These results confirm spatial differences in Hg concentration throughout the North Atlantic-Arctic and an east-west gradient increase in Hg concentrations. Verifying this trend will require more large-scale ecotoxicological studies at smaller spatial resolution.
Keywords: Biologging Feathers Migration North Atlantic-Arctic Pollutant
Programme: 388
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