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Author N. Aubone, M. Saraceno, M. L. Torres Alberto, J. Campagna, L. Le Ster, B. Picard, M. Hindell, C. Campagna, C. R. Guinet
Title Physical changes recorded by a deep diving seal on the Patagonian slope drive large ecological changes Type Journal
Year 2021 Publication Journal of Marine Systems Abbreviated Journal
Volume 223 Issue Pages 103612
Keywords Elephant seals Malvinas current Patagonian shelf slope Southwestern Atlantic Ocean
Abstract (down) The Patagonian slope is the region where Subantarctic waters and bathymetry give raise to physical and ecological processes that support a rich biodiversity and a large-scale industrial fisheries. Unique among the species that depend on this region is the deep diving southern elephant seal, Mirounga leonina. We report here on changes in the foraging behavior of a female seal explained by the combined effect of a cold and high salinity water mass and a decrease in surface chlorophyll-a concentration. Behavioral and oceanographic data from about 5000 profiles of temperature, conductivity, pressure, light and prey encounters were collected within an area ranging 59.5–61°W and 46–47.5°S, at depths of 300–700 m, on the Patagonian slope, during November–December 2018. A decrease in temperature (0.15 °C) and an increase in salinity (0.03) was found below the mixed layer, during December. Light data revealed a significant increase of irradiance in December (almost reaching the ocean bottom) associated with a decrease of chlorophyll-a in the upper levels. Concomitantly, the seal had a different diving behavior in December, foraging near the surface at night and close to the bottom during daylight hours. Also, the seal doubled the prey capture attempts in December compared to November. This study reveals the importance of ocean physical properties on seal's diving and foraging behavior, and how this changes, although small, can impact on seals diet and body composition during their post-breeding trips.
Programme 1201
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0924-7963 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8771
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Author Emilia Trudnowska, Léo Lacour, Mathieu Ardyna, Andreas Rogge, Jean Olivier Irisson, Anya M. Waite, Marcel Babin, Lars Stemmann
Title Marine snow morphology illuminates the evolution of phytoplankton blooms and determines their subsequent vertical export Type Journal
Year 2021 Publication Nature Communications Abbreviated Journal
Volume 12 Issue 1 Pages 2816
Keywords Carbon cycle Marine biology
Abstract (down) The organic carbon produced in the ocean’s surface by phytoplankton is either passed through the food web or exported to the ocean interior as marine snow. The rate and efficiency of such vertical export strongly depend on the size, structure and shape of individual particles, but apart from size, other morphological properties are still not quantitatively monitored. With the growing number of in situ imaging technologies, there is now a great possibility to analyze the morphology of individual marine snow. Thus, automated methods for their classification are urgently needed. Consequently, here we present a simple, objective categorization method of marine snow into a few ecologically meaningful functional morphotypes using field data from successive phases of the Arctic phytoplankton bloom. The proposed approach is a promising tool for future studies aiming to integrate the diversity, composition and morphology of marine snow into our understanding of the biological carbon pump.
Programme 1164
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2041-1723 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8250
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Author Margot Arnould-Pétré, Charlène Guillaumot, Bruno Danis, Jean-Pierre Féral, Thomas Saucède
Title Individual-based model of population dynamics in a sea urchin of the Kerguelen Plateau (Southern Ocean), Abatus cordatus, under changing environmental conditions Type Journal
Year 2021 Publication Ecological Modelling Abbreviated Journal
Volume 440 Issue Pages 109352
Keywords Climate change Dynamic energy budget Ecological modelling Endemic echinoderm Individual-based model Kerguelen Model sensitivity
Abstract (down) The Kerguelen Islands are part of the French Southern Territories, located at the limit of the Indian and Southern oceans. They are highly impacted by climate change, and coastal marine areas are particularly at risk. Assessing the responses of species and populations to environmental change is challenging in such areas for which ecological modelling can constitute a helpful approach. In the present work, a DEB-IBM model (Dynamic Energy Budget – Individual-Based Model) was generated to simulate and predict population dynamics in an endemic and common benthic species of shallow marine habitats of the Kerguelen Islands, the sea urchin Abatus cordatus. The model relies on a dynamic energy budget model (DEB) developed at the individual level. Upscaled to an individual-based population model (IBM), it then enables to model population dynamics through time as a result of individual physiological responses to environmental variations. The model was successfully built for a reference site to simulate the response of populations to variations in food resources and temperature. Then, it was implemented to model population dynamics at other sites and for the different IPCC climate change scenarios RCP 2.6 and 8.5. Under present-day conditions, models predict a more determinant effect of food resources on population densities, and on juvenile densities in particular, relative to temperature. In contrast, simulations predict a sharp decline in population densities under conditions of IPCC scenarios RCP 2.6 and RCP 8.5 with a determinant effect of water warming leading to the extinction of most vulnerable populations after a 30-year simulation time due to high mortality levels associated with peaks of high temperatures. Such a dynamic model is here applied for the first time to a Southern Ocean benthic and brooding species and offers interesting prospects for Antarctic and sub-Antarctic biodiversity research. It could constitute a useful tool to support conservation studies in these remote regions where access and bio-monitoring represent challenging issues.
Programme 1044
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3800 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8002
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Author F. Bultelle, I. Boutet, S. Devin, F. Caza, Y. St-Pierre, R. Péden, P. Brousseau, P. Chan, D. Vaudry, F. Le Foll, M. Fournier, M. Auffret, B. Rocher
Title Molecular response of a sub-antarctic population of the blue mussel (Mytilus edulis platensis) to a moderate thermal stress Type Journal
Year 2021 Publication Marine Environmental Research Abbreviated Journal
Volume 169 Issue Pages 105393
Keywords 2DE Abiotic stress Biomonitoring Gills Indicator species Kerguelen island Mytilus sp. qRT-PCR Temperature
Abstract (down) The Kerguelen Islands (49°26′S, 69°50′E) represent a unique environment due to their geographical isolation, which protects them from anthropogenic pollution. The ability of the endemic mussel, part of the Mytilus complex, to cope with moderate heat stress was explored using omic tools. Transcripts involved in six major metabolic functions were selected and the qRT-PCR data indicated mainly changes in aerobic and anaerobic energy metabolism and stress response. Proteomic comparisons revealed a typical stress response pattern with cytoskeleton modifications and elements suggesting increased energy metabolism. Results also suggest conservation of protein homeostasis by the long-lasting presence of HSP while a general decrease in transcription is observed. The overall findings are consistent with an adaptive response to moderate stresses in mussels in good physiological condition, i.e. living in a low-impact site, and with the literature concerning this model species. Therefore, local blue mussels could be advantageously integrated into biomonitoring strategies, especially in the context of Global Change.
Programme 409
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0141-1136 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8256
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Author Simon Thomas, Pierre-Louis Blelly, Aurelie Marchaudon, Julian Eisenbeis, Samuel Bird
Title Simulating the Response of the Ionosphere in IPIM to Extreme Space Weather Type Communication
Year 2021 Publication AGU Fall Meeting 2021, 13-17 December 2021, New Orleans, USA Abbreviated Journal
Volume 2021 Issue Pages SM45C-2291
Keywords
Abstract (down) 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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Area Expedition Conference
Notes Approved yes
Call Number Serial 8524
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Author Scott A. Shaffer, Pierre Blévin, Christophe Barbraud, Olivier Chastel, Henri Weimerskirch
Title Comparative egg attendance patterns of incubating polar petrels Type Journal
Year 2021 Publication Animal Biotelemetry Abbreviated Journal
Volume 9 Issue 1 Pages 17
Keywords Biologging Cape petrel Egg neglect Egg temperatures Egg turning rates Snow petrel
Abstract (down) The internal environment of eggs in most birds is regulated by transferring heat energy through contact incubation, maintaining nest microclimate, and frequent egg turning by the incubating parent on its nest. However, we lack information about egg attendance patterns in birds that breed in polar environments where variations in life history are expected to influence incubation behavior. Moreover, crevice/burrow nesting petrels in high-latitude regions are known for periodically leaving their egg unattended (hereafter ‘egg neglect’), but there is little reporting on the internal condition of unattended eggs. At Dumont d’Urville Station, Antarctica, we studied the incubation behavior of 24 snow (Pagodroma nivea) and 15 Cape (Daption capense) petrel pairs using egg loggers that recorded egg turning rates, orientation changes, and temperatures at 1 Hz for durations of 3–6 days.
Programme 109
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-3385 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8091
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Author Gareth Chisham, Angeline G. Burrell, Aurélie Marchaudon, Simon G. Shepherd, Evan G. Thomas, Pasha Ponomarenko
Title Comparison of interferometer calibration techniques for improved SuperDARN elevation angles Type Journal
Year 2021 Publication Polar Science Abbreviated Journal
Volume 28 Issue Pages 100638
Keywords Geolocation HF radar Interferometer calibration Ionosphere SuperDARN
Abstract (down) The high frequency radars in the Super Dual Auroral Radar Network (SuperDARN) estimate the elevation angles of returned backscatter using interferometric techniques. These elevation angles allow the ground range to the scattering point to be estimated, which is crucial for the accurate geolocation of ionospheric measurements. For elevation angles to be accurately estimated, it is important to calibrate the interferometer measurements by determining the difference in the signal time delays caused by the difference in the electrical path lengths from the main array and the interferometer array to the point at which the signals are correlated. This time delay is known as tdiff. Several methods have been proposed to estimate tdiff using historical observations; these methods are summarised in this paper. Comparisons of the tdiff estimates from the different calibration methods are presented and sources of uncertainty discussed. The effect of errors in the estimated tdiff value on the accuracy of geolocation is evaluated and discussed. The paper concludes with a series of recommendations for both scientific SuperDARN data users and SuperDARN radar operators.
Programme 312
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1873-9652 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8088
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Author Éric Bernard, Jean-Michel Friedt, Madeleine Griselin
Title Snowcover Survey over an Arctic Glacier Forefield: Contribution of Photogrammetry to Identify “Icing” Variability and Processes Type Journal
Year 2021 Publication Remote Sensing Abbreviated Journal
Volume 13 Issue 10 Pages 1978
Keywords arctic cryosphere moraine photogrammetry snow water equivalent snowcover spatial dynamics UAV-SfM
Abstract (down) The global climate shift currently underway has significant impacts on both the quality and quantity of snow precipitation. This directly influences the spatial variability of the snowpack as well as cumulative snow height. Contemporary glacier retreat reorganizes periglacial morphology: while the glacier area decreases, the moraine area increases. The latter is becoming a new water storage potential that is almost as important as the glacier itself, but with considerably more complex topography. Hence, this work fills one of the missing variables of the hydrological budget equation of an arctic glacier basin by providing an estimate of the snow water equivalent (SWE) of the moraine contribution. Such a result is achieved by investigating Structure from Motion (SfM) image processing that is applied to pictures collected from an Unmanned Aerial Vehicle (UAV) as a method for producing snow depth maps over the proglacial moraine area. Several UAV campaigns were carried out on a small glacial basin in Spitsbergen (Arctic): the measurements were made at the maximum snow accumulation season (late April), while the reference topography maps were acquired at the end of the hydrological year (late September) when the moraine is mostly free of snow. The snow depth is determined from Digital Surface Model (DSM) subtraction. Utilizing dedicated and natural ground control points for relative positioning of the DSMs, the relative DSM georeferencing with sub-meter accuracy removes the main source of uncertainty when assessing snow depth. For areas where snow is deposited on bare rock surfaces, the correlation between avalanche probe in-situ snow depth measurements and DSM differences is excellent. Differences in ice covered areas between the two measurement techniques are attributed to the different quantities measured: while the former only measures snow accumulation, the latter includes all of the ice accumulation during winter through which the probe cannot penetrate, in addition to the snow cover. When such inconsistencies are observed, icing thicknesses are the source of the discrepancy that is observed between avalanche probe snow cover depth measurements and differences of DSMs.
Programme 1108
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Series Editor Series Title Abbreviated Series Title
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Notes Approved yes
Call Number Serial 4442
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Author Damien Ertz, Neil Sanderson, Marc Lebouvier
Title Thelopsis challenges the generic circumscription in the Gyalectaceae and brings new insights to the taxonomy of Ramonia Type Journal
Year 2021 Publication The Lichenologist Abbreviated Journal
Volume 53 Issue 1 Pages 45-61
Keywords Arthoniales Gyalectales lichen multispory phylogeny
Abstract (down) The genus Thelopsis was classified in the family Stictidaceae but its systematic position has never been investigated by molecular methods. In order to determine its family placement and to test its monophyly, fungal DNA of recent collections of Thelopsis specimens was sequenced. Phylogenetic analyses using nuLSU, RPB2 and mtSSU sequences reveal that members of Thelopsis form a monophyletic group within the genus Gyalecta as currently accepted. The placement of Thelopsis, including the generic type T. rubella, within the genus Gyalecta challenges the generic circumscription of this group because Thelopsis is well recognized by the combination of morphological characters: perithecioid ascomata, well-developed periphysoids, polysporous asci and small, few-septate ellipsoid-oblong ascospores. The sterile sorediate Opegrapha corticola is also placed in the Gyalectaceae as sister species to Thelopsis byssoidea + T. rubella. Ascomata of O. corticola are illustrated for the first time and support its placement in the genus Thelopsis. The hypothesis that O. corticola might represent the sorediate fertile morph of T. rubella is not confirmed because the species is phylogenetically and morphologically distinct. Thelopsis is recovered as polyphyletic, with T. melathelia being placed as sister species to Ramonia. The new combinations Thelopsis corticola (Coppins & P. James) Sanderson & Ertz comb. nov. and Ramonia melathelia (Nyl.) Ertz comb. nov. are introduced and a new species of Gyalecta, G. amsterdamensis Ertz, is described from Amsterdam and Saint-Paul Islands, characterized by a sterile thallus with discrete soralia. Petractis luetkemuelleri and P. nodispora are accommodated in the new genus Neopetractis, differing from the generic type (P. clausa) by having a different phylogenetic position and a different photobiont. Francisrosea bicolor Ertz & Sanderson gen. & sp. nov. is described for a sterile sorediate lichen somewhat similar to Opegrapha corticola but having an isolated phylogenetic position as sister to a clade including Gyalidea praetermissa and the genera Neopetractis and Ramonia. Gyalecta farlowii, G. nidarosiensis and G. carneola are placed in a molecular phylogeny for the first time. The taxonomic significance of morphological characters in Gyalectaceae is discussed.
Programme 1167
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0024-2829, 1096-1135 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7078
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Author Zachary J. Oppler, Kayleigh R. O’Keeffe, Karen D. McCoy, Dustin Brisson
Title Evolutionary Genetics of Borrelia Type Journal
Year 2021 Publication Current issues in molecular biology Abbreviated Journal
Volume 42 Issue Pages 97-112
Keywords
Abstract (down) The genus Borrelia consists of evolutionarily and genetically diverse bacterial species that cause a variety of diseases in humans and domestic animals. These vector-borne spirochetes can be classified into two major evolutionary groups, the Lyme borreliosis clade and the relapsing fever clade, both of which have complex transmission cycles during which they interact with multiple host species and arthropod vectors. Molecular, ecological, and evolutionary studies have each provided significant contributions towards our understanding of the natural history, biology and evolutionary genetics of Borrelia species; however, integration of these studies is required to identify the evolutionary causes and consequences of the genetic variation within and among Borrelia species. For example, molecular and genetic studies have identified the adaptations that maximize fitness components throughout the Borrelia lifecycle and enhance transmission efficacy but provide limited insights into the evolutionary pressures that have produced them. Ecological studies can identify interactions between Borrelia species and the vertebrate hosts and arthropod vectors they encounter and the resulting impact on the geographic distribution and abundance of spirochetes but not the genetic or molecular basis underlying these interactions. In this review we discuss recent findings on the evolutionary genetics from both of the evolutionarily distinct clades of Borrelia species. We focus on connecting molecular interactions to the ecological processes that have driven the evolution and diversification of Borrelia species in order to understand the current distribution of genetic and molecular variation within and between Borrelia species.
Programme 333
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1467-3037 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8521
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