Thiebot Jb, Pinaud D, . (2010). Quantitative method to estimate species habitat use from light-based geolocation data
. Endangered Species Research, 10, 341–353.
Abstract: The development of biologging techniques has been instrumental in studying the behaviour of wild animals and interpreting it with respect to the bio-physical features of their habi- tat. Light-based geolocation currently appears to be the only technique suitable for the study of far- ranging small species, particularly marine species, over long periods, but it provides locations with low precision. In this study, we sought to improve the exploitation of these data. Specifically, the goals were to (1) correct rather than reject estimates, especially during equinox periods, (2) perform repro- ducible time-saving routine analyses, and (3) determine the spatial likelihood of the estimations to adapt inferences on habitat use by the population. We therefore applied an existing data-processing method based on spatial template fitting, using Markov Chain Monte Carlo and state-space model- ling (Kalman filter) improved by a facultative sea surface temperature-matching procedure and a land mask. The main functions used for geolocation are grouped under the R package TripEstima- tion, freely available online. We focused on a typical example of animal movement that at present can only be ethically obtained from light-based geolocation. The method made it possible to estimate realistic positions during equinox periods and to routinely process the 12 available datasets. We thus obtained the most probable location for each sunrise/sunset as well as the posterior distribution around each estimated location, allowing an intuitive habitat use investigation at a scale of 100 km. This paper describes the method used and provides the complete and comprehensively annotated commands required for its use.
Keywords: habitat use, kalman filter, large scale movements, light based geolocation, method, permitted without written consent, publisher, resale republication not, sea surface temperature, state space model,
Programme: 109
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Ropert-Coudert Y, Beaulieu M, Hanuise N, Kato A, . (2009). Diving into the world of biologging
. Endang Species Res, 10, 21–27.
Abstract: On the occasion of the publication of the proceedings of the Third International Biologging Science Symposium, we present a summary of the incidence of biologging in studies of animal behaviour. Studies investigating diving activity were used as a proxy to examine the use of a biologging technology. Specifically, studies referenced in the Penguiness Book, an internet-based diving database, were used to examine: (1) on which taxa of diving animals biologging is principally used; (2) which countries are the principal users and producers of biologging technology; and (3) the incidence of this approach in peer-reviewed publications. Each of these items is discussed in the light of the intrinsic limitations of biologging approaches.
Keywords: Retrospective study · Diving activity · Manufacturers · Publications · IUCN
Programme: 137
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Laetitia Dadaglio, Julie Dinasquet, Ingrid Obernosterer, Fabien Joux. (2018). Differential responses of bacteria to diatom-derived dissolved organic matter in the Arctic Ocean (Vol. 82).
Abstract: The Arctic sea ice cover is undergoing an unprecedented decline due to climate change. This loss may result in the earlier start of ice algae blooms and more intense phytoplankton blooms, leading to higher concentrations of dissolved organic matter (DOM) derived from primary production. We investigated the response of early summer Arctic bacterial communities to the addition of Arctic diatom-derived DOM through biodegradation experiments in Baffin Bay. DOM produced by the planktonic diatom Chaetoceros neogracilis and the sea ice diatom Fragilariopsis cylindrus was added to seawater from 3 stations with different ice cover (2 ice zones and 1 open water zone) for 12 d. At the 3 stations, the addition of inorganic nutrients (PO4 and NO3) was not sufficient to stimulate bacterial growth compared to the controls, suggesting that bacteria were mainly limited by organic carbon. The addition of DOM from C. neogracilis stimulated bacterial abundance and production, with a more pronounced response in the ice zone compared to the open water zone. The enhanced bacterial metabolism was accompanied by changes in the bacterial community composition determined by 16S rRNA sequencing, driven by operational taxonomic units (OTUs) related to Pseudoalteromonas and Polaribacter that increased in relative abundance with DOM addition. Moreover, in the ice zone, DOM from C. neogracilis induced a priming effect on the bacterial utilization of ambient DOM. Our findings suggest that phytoplankton blooms, through the production of labile organic matter, will strongly affect bacterial heterotrophic activity, composition and dissolved organic carbon cycling in the Arctic Ocean.
Keywords: 16S rRNA sequencing Arctic Ocean Bacterial diversity Bacterial growth Biodegradation Diatom-derived organic matter Sea ice
Programme: 1164
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Jinwen Liu, Markus G. Weinbauer, Cornelia Maier, Minhan Dai, Jean-Pierre Gattuso. (2010). Effect of ocean acidification on microbial diversity and on microbe-driven biogeochemistry and ecosystem functioning (Vol. 61).
Abstract: The ocean absorbs about 25% of anthropogenic CO2 emissions, which alters its chemistry. Among the changes of the carbonate system are an increase in the partial pressure of CO2 (pCO2) and a decline of pH; hence, the whole process is often referred to as 'ocean acidification'. Many microbial processes can be affected either directly or indirectly via a cascade of effects through the response of non-microbial groups and/or through changes in seawater chemistry. We briefly review the current understanding of the impact of ocean acidification on microbial diversity and processes, and highlight the gaps that need to be addressed in future research. The focus is on Bacteria, Archaea, viruses and protistan grazers but also includes total primary production of phytoplankton as well as species composition of eukaryotic phytoplankton. Some species and communities exhibit increased primary production at elevated pCO2. In contrast to their heterocystous counterparts, nitrogen fixation by non-heterocystous cyanobacteria is stimulated by elevated pCO2. The experimental data on the response of prokaryotic production to ocean acidification are not consistent. Very few other microbial processes have been investigated at environmentally relevant pH levels. The potential for microbes to adapt to ocean acidification, at either the species level by genetic change or at the community level through the replacement of sensitive species or groups by non- or less sensitive ones, is completely unknown. Consequently, the impact of ocean acidification on keystone species and microbial diversity needs to be elucidated. Most experiments used a short-term perturbation approach by using cultured organisms; few were conducted in mesocosms and none in situ. There is likely a lot to be learned from observations in areas naturally enriched with CO2, such as vents, upwelling and near-shore areas.
Keywords: Bacteria Meta-analysis Microbe Microbial diversity Ocean acidification Phytoplankton Viruses á Biogeochemistry
Programme: 1008
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Gina E. Moseley, Jørgen Rosvold, Anne Birgitte Gotfredsen, Irka Hajdas, Olivier Gilg, Kristian M. Gregersen, Christoph Spötl, R. Lawrence Edwards. (2019). First pre-modern record of the gyrfalcon (Falco rusticolus) in north-east Greenland (Vol. 38).
Abstract: Gyrfalcon (Falco rusticolus) is the largest falcon in the world. It inhabits a wide range of climate zones in the Northern Hemisphere, from boreal forests in the south of its range to the arid polar deserts of the High Arctic. In Greenland, because of the harsh, remote environments in which gyrfalcons live, research related to the contemporary and pre-modern periods has been limited to the north-west, central west and central east coasts, with no specific investigations being conducted for the north-east. Here, we report the first pre-modern record of a gyrfalcon in north-east Greenland, located at 80.4°N in Kronprins Christian Land. Skin tissue from a decaying gyrfalcon’s body was radiocarbon dated to 769–944 CE (common era) using a terrestrial-only calibration curve, and 1182–1456 CE using a marine-only calibration curve. Since the gyrfalcon has a mixed terrestrial/marine diet, the actual age can be said to belong between these two groups. This limited data, therefore places the presence of the gyrfalcon in north-east Greenland during a period of prolonged elevated temperatures and climate stress associated with the Medieval Climate Anomaly. Whether the gyrfalcon was part of a larger population or a straggler, and whether the species survived the whole of the Medieval Climate Anomaly in north-east Greenland, is unknown.
Keywords: Arctic Arctic Circle Arctic ecology cave climate change geochronology
Programme: 1036
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Katrine Husum, John A. Howe, Agnes Baltzer, Matthias Forwick, Maria Jensen, Patrycja Jernas, Sergei Korsun, Arto Miettinen, Rahul Mohan, Caterina Morigi, Per Inge Myhre, Maarten A. Prins, Kari Skirbekk, Beata Sternal, Michel Boos, Noortje Dijkstra, Simon Troelstra. (2019). The marine sedimentary environments of Kongsfjorden, Svalbard: an archive of polar environmental change.
Abstract: Kongsfjorden, a fjord in north-western Svalbard, is characterized by large environmental gradients driven by meltwater processes along the margins of tidewater glaciers and the inflow of relatively warm Atlantic Water, the main heat source for the European Arctic. These factors make Kongsfjorden a key area to investigate changes in the polar climate–ocean–glacier system and to examine the resulting effects on the marine environment. The aim of this paper is to synthesize knowledge about the marine sedimentary environment in Kongsfjorden since the last deglaciation. Fjords act as natural sedimentary traps, archiving information about past and present environmental conditions and changes. Geological studies of Kongsfjorden have demonstrated a good potential for reconstructing palaeoenvironments and establishing baselines values for the natural climate changes in the Arctic. Palaeoceanographic reconstructions reveal rising water temperatures similar to modern temperatures ca. 12 000 years ago. The extent of warm Atlantic Water entering the fjords influences processes at, and the stability of, the margins of the tidewater glaciers. Enhanced inflow may cause accelerated glacial melting that, in consequence, leads to an increase in the sediment flux from the glacial catchments into the fjord, as observed ca. 12 000 years ago and at present. However, responses of sediment flux to modern environmental changes remain poorly understood, hence long-term and monitoring studies are needed to quantify and model the effects of climate warming on the sedimentary environment of Kongsfjorden.
Keywords: climate deglaciation environment fjord geology sediments
Programme: 1223
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L. Lescarmontier, B. Legresy, N. W. Young, R. Coleman, L. Testut, C. Mayet, P. Lacroix. (2015). Rifting processes and ice-flow modulation observed on Mertz Glacier, East Antarctica (Vol. 61).
Abstract: We investigated the evolution of two major rifts cutting across Mertz Glacier Tongue, East Antarctica, using a combination of satellite images and 60 day sets of GPS data from two stations deployed either side of the western rift in 2007. The eastern rift began to open in the early 1990s, and the western rift initiated in 2002 in conjunction with the collision of a large iceberg with the tongue. Velocity time series derived from the 2007 GPS data exhibited strong variations at tidal periods modulated by sea-surface height and sea-surface slope and reproduced here with a conceptually simple model. We found that opening of the western rift in 2002 leads to a dramatic change in behavior of the tongue as the large range in velocity (700–2400 m a−1) observed in 2000 was largely reduced (1075–1225 m a−1) in 2007. Opening of the western rift decoupled the glacier from the transverse loading on the tongue driven by east–west tidal circulation. This loading previously induced time-varying lateral drag, which caused the large velocity range. Our results suggest changes in the mechanical behavior of an ice tongue impact the dynamics of the outlet glacier system and should be considered in longer-term mass-balance evaluations.
Keywords: Antarctic glaciology calving crevasses glacier flow glacier mechanics
Programme: 688
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Duncan A. Young, Laura E. Lindzey, Donald D. Blankenship, Jamin S. Greenbaum, Alvaro Garcia De Gorordo, Scott D. Kempf, Jason L. Roberts, Roland C. Warner, Tas Van Ommen, Martin J. Siegert, Emmanuel Le Meur. (2015). Land-ice elevation changes from photon-counting swath altimetry: first applications over the Antarctic ice sheet (Vol. 61).
Abstract: Satellite altimetric time series allow high-precision monitoring of ice-sheet mass balance. Understanding elevation changes in these regions is important because outlet glaciers along ice-sheet margins are critical in controlling flow of inland ice. Here we discuss a new airborne altimetry dataset collected as part of the ICECAP (International Collaborative Exploration of the Cryosphere by Airborne Profiling) project over East Antarctica. Using the ALAMO (Airborne Laser Altimeter with Mapping Optics) system of a scanning photon-counting lidar combined with a laser altimeter, we extend the 2003–09 surface elevation record of NASA’s ICESat satellite, by determining cross-track slope and thus independently correcting for ICESat’s cross-track pointing errors. In areas of high slope, cross-track errors result in measured elevation change that combines surface slope and the actual Δz/Δt signal. Slope corrections are particularly important in coastal ice streams, which often exhibit both rapidly changing elevations and high surface slopes. As a test case (assuming that surface slopes do not change significantly) we observe a lack of ice dynamic change at Cook Ice Shelf, while significant thinning occurred at Totten and Denman Glaciers during 2003–09.
Keywords: Antarctic glaciology aerogeophysical measurements glacier mapping glaciological instruments and methods ice-sheet mass balance
Programme: 1053
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Triest J, Alemany O, . (2014). Drill fluid selection for the SUBGLACIOR probe: a review of silicone oil as a drill fluid
. Annals of Glaciology, 55(68), 311–321.
Abstract: As part of the ICE&LASER/SUBGLACIOR projects, an innovative probe called SUBGLACIOR is developed with the aim of perforating the ice sheet down to depths of 3500m in a single season and continuously measuring in situ the isotopic composition of the meltwater and the methane concentration in trapped gases. Ice chips generated by the electromechanical drilling will be removed from the borehole by circulating a drill fluid. The selection of this drill fluid is important as it will have a major impact on the performance and the environmental evaluation. A literature review of drilling liquids is carried out to select potential fluids for further detailed testing. The selected fluids are varying grades of silicone oils, known as linear polydimethylsiloxanes, and ESTISOL™ 140, an aliphatic ester. The requirements for this project are similar to those for other deep ice-core drilling projects but, due to the embedded analytical system and the speed of drilling, there are some specific considerations. Following extensive testing, we conclude that a silicone fluid with a kinematic viscosity of 3mm2 s–1 (3 cSt) is ideally suitable and affordable. This evaluation provides new insights into the use of silicone oils as a drill fluid that are of use to the wider ice-core drilling community.
Programme: 1119
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Alemany O, Chappellaz J, Triest J, Calzas M, Cattani O, Chemin JF, Desbois Q, Desbois T, Duphil R, Falourd S, Grilli R, Guillerme C, Kerstel E, Laurent B, Lefebvre E, Marrocco N, Pascual O, Piard L, Possenti P, Romanini D, Thiebaut V, Yamani R, . (2014). The SUBGLACIOR drilling probe: concept and design
. Annals of Glaciology, 55(68), 233–242.
Abstract: In response to the ‘oldest ice’ challenge initiated by the International Partnerships in Ice Core Sciences (IPICS), new rapid-access drilling technologies through glacier ice need to be developed. These will provide the information needed to qualify potential sites on the Antarctic ice sheet where the deepest section could include ice that is >1Ma old and still in good stratigraphic order. Identifying a suitable site will be a prerequisite for deploying a multi-year deep ice-core drilling operation to elucidate the cause and mechanisms of the mid-Pleistocene transition from 40 ka glacial–interglacial cycles to 100 ka cycles. As part of the ICE&LASERS/SUBGLACIOR projects, we have designed an innovative probe, SUBGLACIOR, with the aim of perforating the ice sheet down to the bedrock in a single season and continuously measuring in situ the isotopic composition of the melted water and the methane concentration in trapped gases. Here we present the general concept of the probe, as well as the various technological solutions that we have favored so far to reach this goal.
Programme: 1119
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