Viblanc Va, Stier A, Bize P, Schull Q, Criscuolo F, Groscolas R, Robin Jp. (2021). The ecophysiology of king penguins : responses to a fluctuating environment. Bachelor's thesis, , .
Abstract: Penguins are sea...birds. These highly evolved marine predators thrive in the oceanic habitat. Yet, they are conflicted – confronted to the duality of a life spent partly at sea, partly on-land. This life style has them subject to a number of very different ecological pressures. The ECONERGY polar project (IPEV #119) seeks to understand how king penguin cope with the constraints they face while living on-land, and the underlying physiological adaptations that allow them to do so. This includes studies dealing with fasting, parasites, predators, aggressive neighbors, climate and human disturbance. I will present some of the advances our project has made over the past decades, and where we will proceed in the years to come with a new project. We aim to understand bird stress from an integrative perspective, building a long-term observatory of penguin physiological responses to a changing world, and determining how breeding performances on land and foraging performances at sea are related.
Programme: 119
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Yan Axel Gomez Coutouly. (2021). Bachelor's thesis, , .
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Crouzet N. (2021). Monitoring warm transiting exoplanets for Ariel with ASTEP+.
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Akers P., Savarino, J., Caillon, N. (2021). Reconstructing Antarctic snow accumulation using nitrogen isotopes of nitrate.
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Barbero A., Grilli R., Blouzon C., Ahmed S., Thomas J.L., Frey M., Huang Y., Caillon N., Savarino J. (2021). Innovative approach for new estimation of NOx snow-source on the Antarctic Plateau.
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. (2021). Nitrogen isotopes (?15N) and oxygen isotope anomalies (?17O, ?18O) in atmospheric nitrogen dioxide : a new perspective for isotopic constraints on oxidation and aerosols formation processes.
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Albertin, S., Savarino, J., Bekki, S., T. Roberts, T., Barret, B., Mao, J., Simpson, W., Law, K. (2021). Isotopic constraints on the sources and fate of atmospheric nitrate in Fairbanks, Alaska: preliminary results of the pre-ALPACA campaign.
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Simon Thomas, Pierre-Louis Blelly, Aurelie Marchaudon, Julian Eisenbeis, Samuel Bird. (2021). Simulating the Response of the Ionosphere in IPIM to Extreme Space Weather (Vol. 2021).
Abstract: The IRAP Plasmasphere Ionosphere Model (IPIM) is an ionospheric model which describes the transport equations of ionospheric plasma species along magnetic closed field lines. As input, the previous iteration of IPIM used basic models to provide estimations of the solar wind conditions, convection, and precipitation within the ionosphere. In this presentation, we discuss the development of a new operational version of IPIM as part of the EUHFORIA project to monitor and forecast space weather conditions and hazards. The developments of the model include using in-situ solar wind observations from the OMNI data set, ionospheric radar data of plasma motions from the Super Dual Auroral Radar Network (SuperDARN), and precipitation data from the Ovation model, as inputs to the model. A new conductivity module for low latitudes has also been developed for help in the simulation of geomagnetically induced currents. We present the first results from the latest IPIM version which explore the ionosphere's response to different solar wind conditions, before focussing on an extreme coronal mass ejection on 14th July 2012 with clear magnetic cloud and southward magnetic field. For this event, we explore simulations of important plasma properties of the ionosphere and compare with previous model iterations and all available observations and hence describe the skill of using IPIM as a space weather forecasting tool.
Programme: 312
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G. J. Sutton, C. A. Bost, A. Z. Kouzani, S. D. Adams, K. Mitchell, J. P. Y. Arnould. (2021). Fine-scale foraging effort and efficiency of Macaroni penguins is influenced by prey type, patch density and temporal dynamics (Vol. 168).
Abstract: Difficulties quantifying in situ prey patch quality have limited our understanding of how marine predators respond to variation within and between patches, and throughout their foraging range. In the present study, animal-borne video, GPS, accelerometer and dive behaviour data loggers were used to investigate the fine-scale foraging behaviour of Macaroni penguins (Eudyptes chrysolophus) in response to prey type, patch density and temporal variation in diving behaviour. Individuals mainly dived during the day and utilised two strategies, targeting different prey types. Subantarctic krill (Euphausia vallentini) were consumed during deep dives, while small soft-bodied fish were captured on shallow dives or during the ascent phase of deep dives. Despite breeding in large colonies individuals seemed to be solitary foragers and did not engage with conspecifics in coordinated behaviour as seen in other group foraging penguin species. This potentially reflects the high abundance and low manoeuvrability of krill. Video data were used to validate prey capture signals in accelerometer data and a Support Vector Machine learning algorithm was developed to identify prey captures that occurred throughout the entire foraging trip. Prey capture rates indicated that Macaroni penguins continued to forage beyond the optimal give up time. However, bout-scale analysis revealed individuals terminated diving behaviour for reasons other than patch quality. These findings indicate that individuals make complex foraging decisions in relation to their proximate environment over multiple spatio-temporal scales.
Programme: 394
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. (2021). Food source diversity, trophic plasticity, and omnivory enhance the stability of a shallow benthic food web from a high-Arctic fjord exposed to freshwater inputs (Vol. 66).
Abstract: Under climate change, many Arctic coastal ecosystems receive increasing amounts of freshwater, with ecological consequences that remain poorly understood. In this study, we investigated how freshwater inputs may affect the small-scale structure of benthic food webs in a low-production high-Arctic fjord (Young Sound, NE Greenland). We seasonally sampled benthic invertebrates from two stations receiving contrasting freshwater inputs: an inner station exposed to turbid and nutrient-depleted freshwater flows and an outer station exposed to lower terrestrial influences. Benthic food web structure was described using a stable isotope approach (?13C and ?15N), Bayesian models, and community-wide metrics. The results revealed the spatially and temporally homogeneous structure of the benthic food web, characterized by high trophic diversity (i.e., a wide community isotopic niche). Such temporal stability and spatial homogeneity mirrors the high degree of trophic plasticity and omnivory of benthic consumers that allows the maintenance of several carbon pathways through the food web despite different food availability. Furthermore, potential large inputs of shelf organic matter together with local benthic primary production (i.e., macroalgae and presumably microphytobenthos) may considerably increase the stability of the benthic food web by providing alternative food sources to locally runoff-impacted pelagic primary production. Future studies should assess beyond which threshold limit a larger increase in freshwater inputs might cancel out these stability factors and lead to marked changes in Arctic benthic ecosystems.
Programme: 1158
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