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. (2022). Long Distance Runners in the Marine Realm: New Insights Into Genetic Diversity, Kin Relationships and Social Fidelity of Indian Ocean Male Sperm Whales (Vol. 9).
Abstract: Adult male sperm whales (Physeter macrocephalus) are long distance runners of the marine realm, feeding in high latitudes and mating in tropical and subtropical waters where stable social groups of females and immatures live. Several areas of uncertainty still limit our understanding of their social and breeding behavior, in particular concerning the potential existence of geographical and/or social fidelities. In this study, using underwater observation and sloughed-skin sampling, we looked for male social fidelity to a specific matrilineal sperm whale group near Mauritius. In addition, we captured a wider picture of kin relationships and genetic diversity of male sperm whales in the Indian Ocean thanks to biopsies of eight individuals taken in a feeding ground near the Kerguelen and Crozet Archipelagos (Southern Indian Ocean). Twenty-six adult male sperm whales were identified when socializing with adult females and immatures off Mauritius. Sloughed-skin samples were taken from thirteen of them for genetic analysis. Long-term underwater observation recorded several noteworthy social interactions between adult males and adult females and/or immatures. We identified seven possible male recaptures over different years (three by direct observation, and four at the gametic level), which supports a certain level of male social fidelity. Two probable first- and thirty second-degree kin relationships were highlighted between members of the social unit and adult males, confirming that some of the adult males observed in Mauritian waters are reproductive. Male social philopatry to their natal group can be excluded, as none of the males sampled shared the haplotype characteristic of the matrilineal social group. Mitochondrial DNA control region haplotype and nucleotide diversities calculated over the 21 total male sperm whales sampled were similar to values found by others in the Indian Ocean. Our study strongly supports the existence of some levels of male sperm whale social fidelity, not directed to their social group of birth, in the Indian Ocean. Males sampled in breeding and feeding grounds are linked by kin relationships. Our results support a model of male mediated gene flow occurring at the level of the whole Indian Ocean, likely interconnected with large-scale geographical fidelity to ocean basin, and a small-scale social fidelity to matrilineal social groups.
Programme: 109
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. (2022). First evidence of migration across the South Pacific in endangered Amsterdam albatross and conservation implications (Vol. 136).
Abstract: Albatrosses are amongst the most globally-threatened species and fisheries bycatch is one of the major conservation issues worldwide. Among the albatrosses the Amsterdam albatross is listed as one of the most endangered species. Within the current National Plan of Actions framework, the present study outlines the first results of a multi-year survey evaluating juvenile dispersal and immature at sea distribution using geolocation and conservation implications. Here we report the first evidence of an Amsterdam albatross wandering for extensive periods outside the Indian Ocean, in the Pacific Ocean. This unprecedented and novel finding is discussed in terms of overlaps with fisheries and conservations issues. This study brings new insights on movements of vagrant stages of an endangered species, paving the way for refined assessments updates of species vulnerability to ongoing anthropogenic threats while providing basic conservation guidance. This makes it possible to point out the responsibility of the various management bodies both for the high seas regional fisheries management organisations and for exclusive economic zones.
Keywords: Immature at sea distribution International conservation responsibility Juvenile dispersal National Plan of Actions
Programme: 109
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. (2022). (Vol. 697). Bachelor's thesis, , .
Keywords: Activity pattern At-sea distribution Bill width Geolocation GPS Pachyptila macgillivrayi Seabirds Southern Indian Ocean Trophic position
Programme: 109,394
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. (2022). Variation and correlation in the timing of breeding of North Atlantic seabirds across multiple scales (Vol. 91).
Abstract: Timing of breeding, an important driver of fitness in many populations, is widely studied in the context of global change, yet despite considerable efforts to identify environmental drivers of seabird nesting phenology, for most populations we lack evidence of strong drivers. Here we adopt an alternative approach, examining the degree to which different populations positively covary in their annual phenology to infer whether phenological responses to environmental drivers are likely to be (a) shared across species at a range of spatial scales, (b) shared across populations of a species or (c) idiosyncratic to populations. We combined 51 long-term datasets on breeding phenology spanning 50 years from nine seabird species across 29 North Atlantic sites and examined the extent to which different populations share early versus late breeding seasons depending on a hierarchy of spatial scales comprising breeding site, small-scale region, large-scale region and the whole North Atlantic. In about a third of cases, we found laying dates of populations of different species sharing the same breeding site or small-scale breeding region were positively correlated, which is consistent with the hypothesis that they share phenological responses to the same environmental conditions. In comparison, we found no evidence for positive phenological covariation among populations across species aggregated at larger spatial scales. In general, we found little evidence for positive phenological covariation between populations of a single species, and in many instances the inter-year variation specific to a population was substantial, consistent with each population responding idiosyncratically to local environmental conditions. Black-legged kittiwake Rissa tridactyla was the exception, with populations exhibiting positive covariation in laying dates that decayed with the distance between breeding sites, suggesting that populations may be responding to a similar driver. Our approach sheds light on the potential factors that may drive phenology in our study species, thus furthering our understanding of the scales at which different seabirds interact with interannual variation in their environment. We also identify additional systems and phenological questions to which our inferential approach could be applied.
Keywords: breeding time climate change macroecology multispecies phenology
Programme: 330
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. (2022). First Time Identification of Selenoneine in Seabirds and Its Potential Role in Mercury Detoxification (Vol. 56).
Abstract: Birds are principally exposed to selenium (Se) through their diet. In long-lived and top predator seabirds, such as the giant petrel, extremely high concentrations of Se are found. Selenium speciation in biota has aroused great interest in recent years; however, there is a lack of information about the chemical form of Se in (sea)birds. The majority of publications focus on the growth performance and antioxidant status in broilers in relation to Se dietary supplementation. The present work combines elemental and molecular mass spectrometry for the characterization of Se species in wild (sea)birds. A set of eight giant petrels (Macronectes sp.) with a broad age range from the Southern Ocean were studied. Selenoneine, a Se-analogue of ergothioneine, was identified for the first time in wild avian species. This novel Se-compound, previously reported in fish, constitutes the major Se species in the water-soluble fraction of all of the internal tissues and blood samples analyzed. The levels of selenoneine found in giant petrels are the highest reported in animal tissues until now, supporting the trophic transfer in the marine food web. The characterization of selenoneine in the brain, representing between 78 and 88% of the total Se, suggests a crucial role in the nervous system. The dramatic decrease of selenoneine (from 68 to 3%) with an increase of Hg concentrations in the liver strongly supports the hypothesis of its key role in Hg detoxification.
Programme: 109
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. (2022). Clean air policies are key for successfully mitigating Arctic warming (Vol. 3).
Keywords: Atmospheric chemistry Climate-change mitigation
Programme: 1255
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Kristin N. Barton, Nairita Pal, Steven R. Brus, Mark R. Petersen, Brian K. Arbic, Darren Engwirda, Andrew F. Roberts, Joannes J. Westerink, Damrongsak Wirasaet, Michael Schindelegger. (2022). Global Barotropic Tide Modeling Using Inline Self-Attraction and Loading in MPAS-Ocean (Vol. 14).
Abstract: We examine ocean tides in the barotropic version of the Model for Prediction Across Scales (MPAS-Ocean), the ocean component of the Department of Energy Earth system model. We focus on four factors that affect tidal accuracy: self-attraction and loading (SAL), model resolution, details of the underlying bathymetry, and parameterized topographic wave drag. The SAL term accounts for the tidal loading of Earth's crust and the self-gravitation of the ocean and the load-deformed Earth. A common method for calculating SAL is to decompose mass anomalies into their spherical harmonic constituents. Here, we compare a scalar SAL approximation versus an inline SAL using a fast spherical harmonic transform package. Wave drag accounts for energy lost by breaking internal tides that are produced by barotropic tidal flow over topographic features. We compare a series of successively finer quasi-uniform resolution meshes (62.9, 31.5, 15.7, and 7.87 km) to a variable resolution (45 to 5 km) configuration. We ran MPAS-Ocean in a single-layer barotropic mode forced by five tidal constituents. The 45 to 5 km variable resolution mesh obtained the best total root-mean-square error (5.4 cm) for the deep ocean (1,000 m) tide compared to TPXO8 and ran twice as fast as the quasi-uniform 8 km mesh, which had an error of 5.8 cm. This error is comparable to those found in other forward (non-assimilative) ocean tide models. In future work, we plan to use MPAS-Ocean to study tidal interactions with other Earth system components, and the tidal response to climate change.
Keywords: barotropic tides E3SM MPAS-Ocean numerical ocean modeling self-attraction and loading surface tides
Programme: 688
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Kyriakos Balidakis, Roman Sulzbach, Linus Shihora, Christoph Dahle, Robert Dill, Henryk Dobslaw. (2022). Atmospheric Contributions to Global Ocean Tides for Satellite Gravimetry (Vol. 14).
Keywords: atmospheric forcing atmospheric tides de-aliasing ERA5 GRACE-FO ocean tides
Programme: 688
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Lassalle Coralie. (2022). Apport des isotopes de l’eau pour comprendre la dynamique climatique et le cycle hydrologique en Terre Adélie.
Abstract: Dans un contexte de réchauffement climatique, la compréhension de l’évolution passée et future du climat dans le monde représente un enjeu majeur, dans la mesure où la calotte Antarctique peut contribuer à la hausse du niveau marin de près de 60 m. De ce fait, il est important d’appréhender et de documenter la variabilité climatique récente impactant le bilan de masse de surface antarctique, plus spécifiquement dans les régions côtières. Néanmoins, les enregistrements issus des observations instrumentales et satellitaires sont bien trop courts pour faire la distinction entre la variabilité naturelle du signal climatique et l’impact anthropique. D’où le lancement du raid scientifique ASUMA (« Improving the Accurancy of SUrface Mass balance of Antarctica »), dans le cadre de l’ANR (« Agence Nationale de la Recherche »), en Terre Adélie, zone côtière à fort taux d’accumulation caractérisée par la présence de vents catabatiques, afin de mieux connaitre l’évolution actuelle du bilan de masse. Un volet du projet est d’analyser la composition isotopique des carottes de névé dans l’objectif de fournir des informations sur le cycle hydrologique atmosphérique et la dynamique climatique. D’ailleurs, Sentia GOURSAUD (2018) montre que, dans la région côtière de Terre Adélie, la composition isotopique ne dépend pas que de la température de surface locale mais qu’elle est aussi sous l’influence d’autres facteurs (dynamique atmosphérique, sources et transport de l’humidité, phénomènes post-déposition). Dans ce rapport, deux sites de forages de carottes courtes du programme ASUMA ont été étudiés dans l’objectif de faire un transect le long de la pente menant au haut plateau antarctique, entre les points D47 à 1550 m d’altitude et STOP_0 à 2460m. Les mesures isotopiques effectuées ont permis de reconstruire la variabilité climatique sur les 50 dernières années grâce à une méthode analytique continue, l’analyse en flux continu ou CFA (« Continuous Flow Analysis »). Bien que cette méthode soit utilisée en laboratoire depuis quelques années, elle a été récemment développée au LSCE sur les carottes de névé.
Programme: 1205
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. (2022). Bioaccumulation of Per and Polyfluoroalkyl Substances in Antarctic Breeding South Polar Skuas (Catharacta maccormicki) and Their Prey (Vol. 9).
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