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Angelier, F., Bost, C.A., Giraudeau, M., Bouteloup, G., Dano, S., Chastel, O. (2007). Corticosterone and foraging effort in a diving seabird: The Adélie penguin..
Abstract: 6th Penguin Conférence, Hobart, 2-7 septembre 2007.
Programme: 394
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Angélique Melet, Benoit Meyssignac, Rafael Almar, Gonéri Le Cozannet. (2018). Under-estimated wave contribution to coastal sea-level rise (Vol. 8). Bachelor's thesis, , .
Abstract: Coastal communities are threatened by sea-level changes operating at various spatial scales; global to regional variations are associated with glacier and ice sheet loss and ocean thermal expansion, while smaller coastal-scale variations are also related to atmospheric surges, tides and waves. Here, using 23 years (1993–2015) of global coastal sea-level observations, we examine the contribution of these latter processes to long-term sea-level rise, which, to date, have been relatively less explored. It is found that wave contributions can strongly dampen or enhance the effects of thermal expansion and land ice loss on coastal water-level changes at interannual-to-multidecadal timescales. Along the US West Coast, for example, negative wave-induced trends dominate, leading to negative net water-level trends. Accurate estimates of past, present and future coastal sea-level rise therefore need to consider low-frequency contributions of wave set-up and swash.
Programme: 688
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Angot H, Barret M, Magand O, Ramonet M, Dommergue A, . (2014). A 2-year record of atmospheric mercury species at a background Southern Hemisphere station on Amsterdam Island
. Atmospheric Chemistry and Physics, 14(20), 11461–11473.
Abstract: Although essential to fully understand the cycling of mercury at the global scale, mercury species records in the Southern Hemisphere are scarce. Under the framework of the Global Mercury Observation System (GMOS) project, a monitoring station has been set up on Amsterdam Island (37°48´ S, 77°34´ E) in the remote southern Indian Ocean. For the first time in the Southern Hemisphere, a 2-year record of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particle-bound mercury (PBM) is presented. GEM concentrations were remarkably steady (1.03 ± 0.08 ng m−3) while RGM and PBM concentrations were very low and exhibited a strong variability (mean: 0.34 pg m−3, range: < detection limit–4.07 pg m−3; and mean: 0.67 pg m−3, range: < detection limit–12.67 pg m−3, respectively). Despite the remoteness of the island, wind sector analysis, air mass back trajectories and the observation of radonic storms highlighted a long-range contribution from the southern African continent to the GEM and PBM budgets from July to September during the biomass burning season. Low concentrations of GEM were associated with southerly polar and marine air masses from the remote southern Indian Ocean. This unique data set provides new baseline GEM concentrations in the Southern Hemisphere midlatitudes while mercury speciation along with upcoming wet deposition data will help to improve our understanding of the mercury cycle in the marine boundary layer.
Programme: 416,1028
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Angot Helene, Magand Olivier, Barret Manuel, Ramonet Michel, Dommergue Aurelien. (2014). Cycle atmosphérique du mercure dans les régions antarctiques et sub-antarctiques.
Abstract: 24e Réunion des Sciences de la Terre, Pau, 29 octobre 2014
Programme: 1028
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Angot, H., Dommergue, A., Magand, O., Helmig, D., Pirrone, N., and Sprovieri, F. (2015). Year-round record of gaseous mercury in air and snow: new insights into mercury reactivity in Central Antarctica (Dome C).
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Angot, H., Dommergue, A., Magand, O., Helmig, D., Pirrone, N., and Sprovieri, F.:. (2015). Year-round record of gaseous mercury in air and snow: new insights into mercury reactivity in Central Antarctica (Dome C.
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Angot, H., Magand, O., Helmig, D., Ricaud, P., Quennehen, B., Gallée, H., Del Guasta, M., Sprovieri, F., Pirrone, N., Savarino, J., and Dommergue, A. (2016). New insights into the atmospheric mercury cycling in central Antarctica and implications on a continental scale. ATMOSPHERIC CHEMISTRY AND PHYSICS, 16(13), 8249–8264.
Abstract: Under the framework of the GMOS project (Global Mercury Observation System) atmospheric mercury monitoring has been implemented at Concordia Station on the high-altitude Antarctic plateau (75°06′ S, 123°20′ E, 3220 m above sea level). We report here the first year-round measurements of gaseous elemental mercury (Hg(0)) in the atmosphere and in snowpack interstitial air on the East Antarctic ice sheet. This unique data set shows evidence of an intense oxidation of atmospheric Hg(0) in summer (24-hour daylight) due to the high oxidative capacity of the Antarctic plateau atmosphere in this period of the year. Summertime Hg(0) concentrations exhibited a pronounced daily cycle in ambient air with maximal concentrations around midday. Photochemical reactions and chemical exchange at the air–snow interface were prominent, highlighting the role of the snowpack on the atmospheric mercury cycle. Our observations reveal a 20 to 30 % decrease of atmospheric Hg(0) concentrations from May to mid-August (winter, 24 h darkness). This phenomenon has not been reported elsewhere and possibly results from the dry deposition of Hg(0) onto the snowpack. We also reveal the occurrence of multi-day to weeklong atmospheric Hg(0) depletion events in summer, not associated with depletions of ozone, and likely due to a stagnation of air masses above the plateau triggering an accumulation of oxidants within the shallow boundary layer. Our observations suggest that the inland atmospheric reservoir is depleted in Hg(0) in summer. Due to katabatic winds flowing out from the Antarctic plateau down the steep vertical drops along the coast and according to observations at coastal Antarctic stations, the striking reactivity observed on the plateau most likely influences the cycle of atmospheric mercury on a continental scale.
Programme: 910
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Angus F. Henderson, Clive R. McMahon, Rob Harcourt, Christophe Guinet, Baptiste Picard, Simon Wotherspoon, Mark A. Hindell. (2020). Inferring Variation in Southern Elephant Seal At-Sea Mortality by Modelling Tag Failure (Vol. 7).
Abstract: Identifying factors influencing survivorship is key to understanding population persistence. Although satellite telemetry is a powerful tool for studying remote animal ecology and behaviour it is rarely used for demographic studies because distinguishing the death of the animal (individual mortality) from failure of the tag (mechanical tag failure) has proven difficult. Southern elephant seals present an opportunity to separate tag failure from animal mortality thanks to the availability of large tracking datasets, broad knowledge of demographic rates, and because for these large animals, satellite tags are known not to influence mortality rates. A key rationale for investigating satellite telemetry to estimate mortality as compared to using traditional Capture-Mark-Recapture methods is the potential for obtaining spatially and temporally specific information, particularly while the animals are at sea and largely unobservable. We used satellite tag data from 182 seals from Isles Kerguelen, deployed between 2004 and 2018. Of these, 76 (42%) tags transmitted for the full post-moult foraging trip (max. 265 days for females and max. 305 days for sub-adult males) with the remaining 107 tags (58%) ceasing transmission at sea. We found that contrary to expectations, behavioural choices seem not to influence tag failure rates by mechanical means, rather the signals we detected seemed to align with previously described variation in mortality between groups. There was evidence, albeit limited, for an increase in tag failure for adult females in years with negative Southern Annular Mode (lower Southern Ocean productivity). We speculate that this increase in failure may suggest higher mortality in these years. Also, males using the Kerguelen Plateau had higher tag failure rates than those in the sea-ice zone, perhaps indicative of higher mortality. We suspect that these differences in tag failure rates between groups reflect variation in predator exposure and foraging success. This suggests satellite telemetry could be used to infer mortality events for southern elephant seals while they are at sea.
Programme: 1201
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Anika Immer, Thomas Merkling, Olivier Chastel, Scott A. Hatch, Etienne Danchin, Pierrick Blanchard, Sarah Leclaire. (2021). Spying on your neighbours? Social information affects timing of breeding and stress hormone levels in a colonial seabird (Vol. 35).
Abstract: A good overlap between offspring energetic requirements and availability of resources is required for successful reproduction. Accordingly, individuals from numerous species fine-tune their timing of breeding by integrating cues that predict environmental conditions during the offspring period. Besides acquiring information from their direct interaction with the environment (personal information), individuals can integrate information by observing the behaviours or performance of others (social information). The use of social information is often beneficial because the accumulated knowledge of conspecifics may represent a source of information more reliable than the intrinsically more limited personal information. However, although social information constitutes the major source of information in a wide range of contexts, studies investigating its use in the context of timing of breeding are scarce. We investigated whether black-legged kittiwakes (Rissa tridactyla) used social information to adjust the timing of egg-laying. We manipulated social information using a food-supplementation experiment, known to advance kittiwakes' reproductive phenology. We expected food-supplemented and unsupplemented pairs to delay and advance, respectively, their timing of laying when surrounded by a majority of neighbours from the opposite food-treatment. However, both unsupplemented and food-supplemented kittiwakes delayed egg-laying when surrounded by a higher proportion of neighbours from the opposite food-treatment. This result shows that kittiwakes use social information to time egg-laying, but that it is not used to match the seasonal peak of food availability. We suggest that when social and personal cues give contradictory environmental information, individuals may benefit from delaying laying to gather more information to make better decisions about investment into eggs. Further, we explored a potential proximate mechanism for the pattern we report. We show that baseline corticosterone, known to mediate reproductive decisions, was lower in unsupplemented females facing a higher proportion of food-supplemented neighbours. Altogether, our results suggest that to fine-tune their timing of laying, kittiwakes use complex decision-making processes in which social and personal information interplay.
Programme: 1162
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Anklin M., Barnola J.M., Schwander J., Stauffer B. & Raynaud D. (1995). Processes affecting the CO2 concentrations measured in Grennland ice. Tellus series b-chemical and physical meteorology, 47(4), 448–461.
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