Lucie Marandel, Philippe Gaudin, François Guéraud, Stéphane Glise, Alexandre Herman, Elisabeth Plagnes-Juan, Vincent Véron, Stéphane Panserat, Jacques Labonne. (2017). A reassessment of the carnivorous status of salmonids: Hepatic glucokinase is expressed in wild fish in Kerguelen Islands (Vol. 612).
Abstract: Salmonids belong to a high trophic level and are thus considered as strictly carnivorous species, metabolically adapted for high catabolism of proteins and low utilisation of dietary carbohydrates. However they conserved a “mammalian-type” nutritional regulation of glucokinase encoding gene and its enzymatic activity by dietary carbohydrates which remains puzzling regarding their dietary regime. The present study investigates the hypothesis that this conservation could be linked to a real consumption by trout of this nutrient in their natural habitat. To do so, brown trout were sampled in the sub-Antarctic Kerguelen Islands, a site presenting oligotrophic hydrosystems and no local freshwater fish fauna prior the introduction of salmonids fifty years ago. Qualitative and quantitative analysis of carbohydrate content within Kerguelen trout stomachs demonstrate that these animals are fed on food resources containing digestible carbohydrates. Additionally, glycaemia and more particularly gck mRNA level and gck enzymatic activity prove that Kerguelen trout digest and metabolise dietary carbohydrates. Physiological and molecular analyses performed in the present study thus strongly evidence for consumption of dietary carbohydrates by wild trout in natural environments. Investigating differences between Kerguelen individuals, we found that smaller individuals presented higher glycaemia, as well as higher carbohydrates contents in stomach. However no relationship between scaled mass index and any physiological indicator was found. Thus it appears that Kerguelen trout do not turn to carbohydrate diet because of a different condition index, or that the consumption of carbohydrates does not lead to a generally degraded physiological status. As a conclusion, our findings may explain the evolutionary conservation of a “mammalian-type” nutritional regulation of gck by dietary carbohydrates in these carnivorous fish.
Keywords: Carbohydrates Environment Gluconeogenesis Glucose metabolism Polar
Programme: 1041
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Gautier, E
Savarino, J
Farquhar, J
Erbland, J. (2014). A reconstruction of terrestrial volcanism over the last 2500 years using sulfur isotopes in ice-cores, Goldschmidt Conference, Sacramento, USA.
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Gautier, E., Savarino, J., and Farquhar, J.: . (2015). A reconstruction of terrestrial volcanism over the last 2500 years using sulfur isotopes in ice-cores, Our common futur under climate change, UNESCO, Paris
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McCabe, J.R.; Thiemens, M.H.; Savarino, J. (2007). A record of ozone variability in South Pole Antarctic snow: Role of nitrate oxygen isotopes. J. Geophys. Res., 112.
Abstract: The information contained in polar nitrate has been an unresolved issue for over a decade. Here we demonstrate that atmospheric nitrate's oxygen isotopic composition (?17O-NO3) reflects stratospheric chemistry in winter and tropospheric chemistry in summer. Surface snow isotope mass balance indicates that nitrate oxygen isotopic composition is the result of a mixture of 25% stratospheric and 75% tropospheric origin. Analysis of trends in ?17O-NO3 in a 6 m snow pit that provides a 26-year record reveals a strong 2.70-year cycle that anticorrelates (R = ?0.77) with October–November–December column ozone. The potential mechanisms linking the records are either denitrification or increased boundary layer photochemical ozone production. We suggest that the latter is dominating the observed trend and find that surface ozone and ?17O-NO3 correlate well before 1991 (R = 0.93). After 1991, however, the records show no significant relationship, indicating an altered oxidative environment consistent with current understanding of a highly oxidizing atmosphere at the South Pole. The disappearance of seasonal ?17O-NO3 trends in the surface layer at depth remain unresolved and demand further investigation of how postdepositional processes affect nitrate's oxygen isotope composition. Overall, the findings of this study present a new paleoclimate technique to investigate Antarctic nitrate records that appear to reflect trends in stratospheric ozone depletion by recording tropospheric surface ozone variability.
Keywords: nitrate; isotopes; ozone; 1041 Geochemistry: Stable isotope geochemistry; 0305 Atmospheric Composition and Structure: Aerosols and particles; 3344 Atmospheric Processes: Paleoclimatology; 1610 Global Change: Atmosphere; 0776 Cryosphere: Glaciology
Programme: 1011
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Van Houdt J., Van de Putte A., Maes J., Hecq J.-H., Beans C., Koubbi P. & Volckaert F.A.M. (2004). A referential database for the molecular identification of Antarctic fish species and its applications in ecological research..
Abstract: XXVIII SCAR Open Science Conference, Bremen- Allemagne.
Programme: 281
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Sebastian Richter, Richard C. Gerum, Werner Schneider, Ben Fabry, Céline Le Bohec, Daniel P. Zitterbart. (2018). A remote-controlled observatory for behavioural and ecological research: A case study on emperor penguins (Vol. 9).
Abstract: Long-term photographic recordings of animal populations provide unique insights into ecological and evolutionary processes. However, image acquisition at remote locations under harsh climatic conditions is highly challenging. We present a robust, energetically self-sufficient and remote-controlled observatory designed to operate year-round in the Antarctic at temperatures below −50°C and wind speeds above 150 km/h. The observatory is equipped with multiple overview cameras and a high resolution steerable camera with a telephoto lens for capturing images with high spatial and temporal resolution. Our observatory has been in operation since 2013 to investigate an emperor penguin (Aptenodytes forsteri) colony at Atka Bay near the German Neumayer III research station. Data recorded by this observatory give novel biological insights in animal life cycle and demographic trends, but also in collective and individual behaviour. As an example, we present data showing how wind speed and direction influence movements of the entire colony and of individual penguins. We also estimate daily fluctuations in the total number of individuals present at the breeding site. Our results demonstrate that remote-controlled observation systems can bridge the gap between remote sensing, simple time-lapse recording setups, and on-site observations by human investigators to collect unique biological datasets of undisturbed animal populations.
Keywords: animal colony Antarctica behaviour emperor penguin remote-controlled observatory time-lapse imaging
Programme: 137
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Andreassen P. (2015). A retrospective study of the endoparasitic Helminths present in faeces of Arctic Fox (Vulpes lagopus) from Northeastern Greenland.
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Masson-Delmotte, V.; Hou, S.; Ekaykin, A.; Jouzel, J.; Aristarain, A.; Bernardo, R.T.; Bromwich, D.; Cattani, O.; Delmotte, M.; Falourd, S.; Frezzotti, M.; Gallée, H.; Genoni, L.; Isaksson, E.; Landais, A.; Helsen, M.M.; Hoffmann, G.; Lopez, J.; Morgan, V.; Motoyama, H.; Noone, D.; Oerter, H.; Petit, J.R.; Royer, A.; Uemura, R.; Schmidt, G.A.; Schlosser, E.; Simões, J.C.; Steig, E.J.; Stenni, B.; Stievenard, M.; van den Broeke, M.R.; van de Wal, R.S.W.; van de Berg, W.J.; Vimeux, F.; White, J.W.C. (2008). A Review of Antarctic Surface Snow Isotopic Composition: Observations, Atmospheric Circulation, and Isotopic Modeling*. Journal of climate, 21(13), 3359–3387.
Abstract: A database of surface Antarctic snow isotopic composition is constructed using available measurements, with an estimate of data quality and local variability. Although more than 1000 locations are documented, the spatial coverage remains uneven with a majority of sites located in specific areas of East Antarctica. The database is used to analyze the spatial variations in snow isotopic composition with respect to geographical characteristics (elevation, distance to the coast) and climatic features (temperature, accumulation) and with a focus on deuterium excess. The capacity of theoretical isotopic, regional, and general circulation atmospheric models (including “isotopic” models) to reproduce the observed features and assess the role of moisture advection in spatial deuterium excess fluctuations is analyzed.
Keywords: Snow; Antarctica; Atmospheric circulation; Isotopic analysis; In situ observations
Programme: 355;454
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Insley S., Phillips A.V. & Charrier I. (2003). A review of social recognition in pinnipeds. Aquatic mammals, 29(2), 181–201.
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Yves Cherel. (2020). A review of Southern Ocean squids using nets and beaks (Vol. 50).
Abstract: This review presents an innovative approach to investigate the teuthofauna from the Southern Ocean by combining two complementary data sets, the literature on cephalopod taxonomy and biogeography, together with predator dietary investigations. Sixty squids were recorded south of the Subtropical Front, including one circumpolar Antarctic (Psychroteuthis glacialis Thiele, 1920), 13 circumpolar Southern Ocean, 20 circumpolar subantarctic, eight regional subantarctic, and 12 occasional subantarctic species. A critical evaluation removed five species from the list, and one species has an unknown taxonomic status. The 42 Southern Ocean squids belong to three large taxonomic units, bathyteuthoids (n = 1 species), myopsids (n = 1), and oegopsids (n = 40). A high level of endemism (21 species, 50%, all oegopsids) characterizes the Southern Ocean teuthofauna. Seventeen families of oegopsids are represented, with three dominating families, onychoteuthids (seven species, five endemics), ommastrephids (six species, three endemics), and cranchiids (five species, three endemics). Recent improvements in beak identification and taxonomy allowed making new correspondence between beak and species names, such as Galiteuthis suhmi (Hoyle 1886), Liguriella podophtalma Issel, 1908, and the recently described Taonius notalia Evans, in prep. Gonatus phoebetriae beaks were synonymized with those of Gonatopsis octopedatus Sasaki, 1920, thus increasing significantly the number of records and detailing the circumpolar distribution of this rarely caught Southern Ocean squid. The review extends considerably the number of species, including endemics, recorded from the Southern Ocean, but it also highlights that the corresponding species to two well-described beaks (Moroteuthopsis sp. B and Psychroteuthis sp. B) are still unknown.
Programme: 109
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