|
|
Alison F. Banwell, Rajashree Tri Datta, Rebecca L. Dell, Mahsa Moussavi, Ludovic Brucker, Ghislain Picard, Christopher A. Shuman, Laura A. Stevens. (2021). The 32-year record-high surface melt in 2019/2020 on the northern George VI Ice Shelf, Antarctic Peninsula (Vol. 15).
Abstract: In the 2019/2020 austral summer, the surface melt duration and extent on the northern George VI Ice Shelf (GVIIS) was exceptional compared to the 31 previous summers of distinctly lower melt. This finding is based on analysis of near-continuous 41-year satellite microwave radiometer and scatterometer data, which are sensitive to meltwater on the ice shelf surface and in the near-surface snow. Using optical satellite imagery from Landsat 8 (2013 to 2020) and Sentinel-2 (2017 to 2020), record volumes of surface meltwater ponding were also observed on the northern GVIIS in 2019/2020, with 23 % of the surface area covered by 0.62 km3 of ponded meltwater on 19 January. These exceptional melt and surface ponding conditions in 2019/2020 were driven by sustained air temperatures ?0 ?C for anomalously long periods (55 to 90 h) from late November onwards, which limited meltwater refreezing. The sustained warm periods were likely driven by warm, low-speed (?7.5 m s?1) northwesterly and northeasterly winds and not by foehn wind conditions, which were only present for 9 h total in the 2019/2020 melt season. Increased surface ponding on ice shelves may threaten their stability through increased potential for hydrofracture initiation; a risk that may increase due to firn air content depletion in response to near-surface melting.
Programme: 1110
|
|
|
|
Morten Frederiksen, Olivier Gilg, Glenn Yannic. (2021). Cross-icecap spring migration confirmed in a high-Arctic seabird, the Ivory Gull Pagophila eburnea (Vol. 163).
Keywords: ecological barrier Greenland icecap high-altitude migration
Programme: 1210
|
|
|
|
. (2021). Diel at-sea activity of two species of great albatrosses: the ontogeny of foraging and movement behaviour (Vol. 52).
Abstract: The first year of life is a period of high mortality in animals. Reduced foraging capacities of naive individuals might be the primary cause of their mortality. These capacities are supposed to be progressively acquired during the first months of life. In this study, we investigate the ontogeny of flight capacities, by day and night, of first-year individuals, and compare it with adults from two closely related species of great albatrosses: Amsterdam Diomedea amsterdamensis and wandering Diomedea exulans albatrosses which forage in different environmental conditions. We used 71 tracks of 71 juvenile birds and 141 of 116 incubating adults to compare both age categories. In order to explore the effect of moon light on night activity, we elaborated a new formula which improves the precision of the proxy of moon illumination. By day, we found that juveniles of both species reach some adult foraging capacities in less than two months. By night, albatrosses have reduced activity increasing during the first weeks at sea for juveniles and changing in accordance with moon illumination for both juveniles and adults. A peak of flight activity at dawn and dusk was apparent for both species. Interspecific comparison underlined that Amsterdam albatrosses were more active than wandering albatrosses, suggesting a difference in food and foraging strategy. Overall, we highlighted how life history traits, environmental conditions and time of the day affect the foraging activity of two related species of seabirds.
Keywords: albatross diel activity pattern Diomedea flight behavior foraging activity moon illumination night activity seabirds
Programme: 109
|
|
|
|
. (2021). Individual migration strategy fidelity but no habitat specialization in two congeneric seabirds (Vol. 48).
Keywords: guillemots light-level geolocation murres Uria aalge Uria lomvia
Programme: 388
|
|
|
|
. (2021). The biology and feeding ecology of Arctic charr in the Kerguelen Islands (Vol. 98).
|
|
|
|
. (2021). Phylogenomic Resolution of Sea Spider Diversification through Integration of Multiple Data Classes (Vol. 38).
Abstract: Despite significant advances in invertebrate phylogenomics over the past decade, the higher-level phylogeny of Pycnogonida (sea spiders) remains elusive. Due to the inaccessibility of some small-bodied lineages, few phylogenetic studies have sampled all sea spider families. Previous efforts based on a handful of genes have yielded unstable tree topologies. Here, we inferred the relationships of 89 sea spider species using targeted capture of the mitochondrial genome, 56 conserved exons, 101 ultraconserved elements, and 3 nuclear ribosomal genes. We inferred molecular divergence times by integrating morphological data for fossil species to calibrate 15 nodes in the arthropod tree of life. This integration of data classes resolved the basal topology of sea spiders with high support. The enigmatic family Austrodecidae was resolved as the sister group to the remaining Pycnogonida and the small-bodied family Rhynchothoracidae as the sister group of the robust-bodied family Pycnogonidae. Molecular divergence time estimation recovered a basal divergence of crown group sea spiders in the Ordovician. Comparison of diversification dynamics with other marine invertebrate taxa that originated in the Paleozoic suggests that sea spiders and some crustacean groups exhibit resilience to mass extinction episodes, relative to mollusk and echinoderm lineages.
Programme: 1124
|
|
|
|
. (2021). (Vol. 118).
|
|
|
|
Stephanie Jenouvrier, Judy Che-Castaldo, Shaye Wolf, Marika Holland, Sara Labrousse, Michelle LaRue, Barbara Wienecke, Peter Fretwell, Christophe Barbraud, Noah Greenwald, Julienne Stroeve, Philip N. Trathan. (2021). The call of the emperor penguin: Legal responses to species threatened by climate change (Vol. 27).
Abstract: Species extinction risk is accelerating due to anthropogenic climate change, making it urgent to protect vulnerable species through legal frameworks in order to facilitate conservation actions that help mitigate risk. Here, we discuss fundamental concepts for assessing climate change risks to species using the example of the emperor penguin (Aptenodytes forsteri), currently being considered for protection under the US Endangered Species Act (ESA). This species forms colonies on Antarctic sea ice, which is projected to significantly decline due to ongoing greenhouse gas (GHG) emissions. We project the dynamics of all known emperor penguin colonies under different GHG emission scenarios using a climate-dependent meta-population model including the effects of extreme climate events based on the observational satellite record of colonies. Assessments for listing species under the ESA require information about how species resiliency, redundancy and representation (3Rs) will be affected by threats within the foreseeable future. Our results show that if sea ice declines at the rate projected by climate models under current energy system trends and policies, the 3Rs would be dramatically reduced and almost all colonies would become quasi-extinct by 2100. We conclude that the species should be listed as threatened under the ESA.
Keywords: climate risk assessments Endangered Species Act foreseeable future population projections redundancy and representation (3Rs) resiliency sea ice projections species distribution treatment of scientific uncertainty
Programme: 109
|
|
|
|
A. Barbero, J. Savarino, R. Grilli, C. Blouzon, G. Picard, M. M. Frey, Y. Huang, N. Caillon. (2021). New Estimation of the NOx Snow-Source on the Antarctic Plateau (Vol. 126).
Keywords: Antarctic Plateau flux chamber nitrate photolysis snowpack emissions
Programme: 1177
|
|
|
|
Alain Manceau, Romain Brossier, Sarah E. Janssen, Tylor J. Rosera, David P. Krabbenhoft, Yves Cherel, Paco Bustamante, Brett A. Poulin. (2021). Mercury Isotope Fractionation by Internal Demethylation and Biomineralization Reactions in Seabirds: Implications for Environmental Mercury Science (Vol. 55).
|
|
