Regional Variation in Winter Foraging Strategies by Weddell Seals in Eastern Antarctica and the Ross Sea

The relative importance of intrinsic and extrinsic determinants of animal foraging is often difficult to quantify. The most southerly breeding mammal, the Weddell seal, remains in the Antarctic pack-ice year-round. We compared Weddell seals tagged at three geographically and hydrographically distinct locations in East Antarctica (Prydz Bay, Terre Adélie, and the Ross Sea) to quantify the role of individual variability and habitat structure in winter foraging behaviour. Most Weddell seals remained in relatively small areas close to the coast throughout the winter, but some dispersed widely. Individual utilisation distributions (UDi, a measure of the total area used by an individual seal) ranged from 125 to 20,825 km2. This variability was not due to size or sex but may be due to other intrinsic states for example reproductive condition or personality. The type of foraging (benthic vs. pelagic) varied from 56.6 ± 14.9% benthic dives in Prydz Bay through 42.1 ± 9.4% Terre Adélie to only 25.1 ± 8.7% in the Ross Sea reflecting regional hydrographic structure. The probability of benthic diving was less likely the deeper the ocean. Ocean topography was also influential at the population level; seals from Terre Adélie, with its relatively narrow continental shelf, had a core (50%) UD of only 200 km2, considerably smaller than the Ross Sea (1650 km2) and Prydz Bay (1700 km2). Sea ice concentration had little influence on the time the seals spent in shallow coastal waters, but in deeper offshore water they used areas of higher ice concentration. Marine Protected Areas (MPAs) in the Ross Sea encompass all the observed Weddell seal habitat, and future MPAs that include the Antarctic continental shelf are likely to effectively protect key Weddell seal habitat.

Undecided dreams: France in the Antarctic, 1840–2021

This paper traces France’s role in the Antarctic from 1840, when explorer Jules Dumont d’Urville discovered the slice of the white continent he named Terre Adélie, to the present day. Since World War II, Terre Adélie has been the site of a host of performances of sovereignty: the French have built bases, drawn maps, conducted scientific investigations and erected plaques. But France’s commitment to Terre Adélie has been tested and has fallen into crisis several times. The history of France in Antarctica is a tale of ambition, ambivalence, trade-offs and political strategy. This paper aims to elucidate this story, focusing on the concept of sovereignty and the nexus of scientific and political interests. I argue that France’s relationship with the Antarctic has been characterised by continual tension, by peaks and troughs and by brinkmanship on the part of actors with their own stakes. While there is broad agreement that Terre Adélie serves a fundamental national interest, I show that France’s ambitions on the white continent are far from decided. With its focus on France, which has largely been left out of the growing body of literature on the Antarctic, this paper contributes to building a robust historical understanding of Antarctic claims.

Un an en Terre Adélie (5)

Durant cinq numéros de La Météorologie, nous vous proposons un carnet de voyage, une immersion au sein de la base Dumont-d'Urville, située en Terre Adélie. C'est le responsable de la station météorologique, François Gourand, qui nous en propose le récit pendant son séjour de décembre 2019 à novembre 2020. Ce cinquième et dernier article est consacré au vent catabatique.

Antarctic erosion history reconstructed by Terre Adélie moraine geochronology

We report apatite fission-track and 10Be terrestrial cosmogenic nuclide (TCN) dating of 14 moraine boulders originating from inland Terre Adélie, East Antarctica. These data show cooling of the Proterozoic Terre Adélie craton at < ~120°C between 350 and 300 Ma, suggesting > 4 km temperate glacial erosion during the Late Palaeozoic Ice Age, followed by nearly null Mesozoic erosion and low glacial erosion (< 2 km) in the Cenozoic. Based on glacial flux maps, the origin of the boulders may be located ~400 km upstream. Preliminary TCN (10Be) datings of moraine boulders cluster within the last 30 ka. Cosmogenic ages from the Lacroix Nunatak suggest a main deglaciation after the Younger Dryas at c. 10 ka, while those of Cap Prud'homme mostly cluster at 0.6 ka, in agreement with an exhumation of boulders during the Little Ice Age.

Un an en Terre Adélie (3)

Durant cinq numéros de La Météorologie, nous vous proposons un carnet de voyage, une immersion au sein de la base Dumont-d'Urville, située en Terre Adélie. C'est le responsable de la station météorologique, François Gourand, qui nous en propose le récit pendant son séjour de décembre 2019 à décembre 2020. Ce troisième article est consacré au travail de météorologue sur la base.

Un an en Terre Adélie

Durant cinq numéros de La Météorologie, nous vous proposons un carnet de voyage, une immersion au sein de la base de Dumont d'Urville, située en Terre Adélie. C'est le responsable de la station météorologique, François Gourand, qui nous en propose le récit pendant son séjour de décembre 2019 à décembre 2020.

Un an en Terre Adélie (2)

Durant cinq numéros de La Météorologie, nous vous proposons un carnet de voyage, une immersion au sein de la base Dumont-d'Urville, située en Terre Adélie. C'est le responsable de la station météorologique, François Gourand, qui nous en propose le récit pendant son séjour de décembre 2019 à décembre 2020. Ce deuxième article est consacré à l'organisation de la base.

Un an en Terre Adélie (4)

Durant cinq numéros de La Météorologie, nous vous proposons un carnet de voyage, une immersion au sein de la base Dumont-d'Urville, située en Terre Adélie. C'est le responsable de la station météorologique, François Gourand, qui nous en propose le récit pendant son séjour de décembre 2019 à décembre 2020. Ce quatrième article est consacré à la faune que l'on rencontre autour de la base.