Pigmentation and colouration are important to animal fitness. Colourations convey important information and impact predation risk, thermoregulation and mate selection. There are many cases of hypopigmentation across the animal kingdom, and leucism is a common form. We observed a Weddell seal (Leptonychotes weddellii) pup with cream-coloured fur, light skin and white nails multiple times in 2022 in Erebus Bay, Antarctica. The pup was observed 1 year later as a generally healthy yearling. This is the first documentation of a leucistic seal within this well-studied population and the second documentation of such colouration in this species. This seal offers a potential opportunity to observe the effects of hypopigmentation in Antarctic true seals.

Although there is increasing evidence that birds have individual chemical profiles that can be used in different social contexts, partner scent recognition has only been explored in procellariiform seabirds, a group of birds known for their highly developed olfactory system. However, olfaction is not restricted to Procellariiformes, and birds with smaller olfactory bulbs can also use chemical cues in different social contexts. More evidence from different bird groups is needed to disentangle whether olfaction plays a general role in partner recognition. We performed a choice experiment to examine whether chinstrap penguins Pygoscelis antarcticus can discriminate the scent of their partner from the scent of other conspecifics. Our results do not suggest a preference of penguins for the scent of their partners. Our results highlight the need to carry out additional studies to determine the mechanisms underlying partner recognition in penguins.

Antarctic terrestrial ecosystems, covering less than 1% of the continent, are under increasing anthropogenic threats, particularly from climate change and tourism. This study focuses on the impact of human trampling on soil microbial communities in Barrientos Island (South Shetlands archipelago), a frequently visited location. Soil samples were collected within and at the edge of two established paths representing varying levels of human disturbance. Physical and chemical analyses revealed significant differences between the paths, potentially creating anaerobic conditions favorable for specific microbial taxa. Thus, microbial communities also differed between the paths. Aerobic heterotrophic taxa were dominant in the less disturbed path, while anaerobic taxa such as Bacteroidetes vadinHA17 thrived in the more compacted path. Although alpha diversity indices did not differ, beta diversity analyses showed notable distinctions, particularly between the paths rather than trampled and untrampled areas. These findings suggest that microbial communities may recover following the stop of human activity, but also that indigenous microbial communities or other overlooked factors may be influencing the recovery potential. This study thus offers a starting point for similar research, as it highlights the need for further investigation to determine whether human trampling or other environmental factors are primarily responsible for these differences.

Sub-Antarctic marine life exhibits unique ecological traits and pronounced endemicity levels. Despite their ecological uniqueness and high conservation value, studies on sub-Antarctic benthic communities are scarce. Using underwater video imagery, we assessed the nearshore diversity and structure of faunal and algal communities of the Crozet archipelago along 12 scuba and remotely operated vehicle transects performed at Baie du Marin and Crique du Sphinx (Ile de la Possession). The influence of habitat types on species distribution was evaluated in relation to the setting up of submarine cables. A total of 51 faunal (mainly represented by Echinodermata and Porifera) and 14 algal (mainly represented by Rhodophyta) taxa were identified. The high habitat heterogeneity found in shallow waters (from 0 to 20 m depth) enhances the species richness and diversity, whereas deeper (> 20 m depth) areas were dominated by large sandy stretches and a lower diversity. Rocky habitats had the highest richness and diversity values, promoting local diversity. Submarine cables act as a hard substrate for species, whose suspended sections influence the composition and structure of benthic communities. This study improves our limited knowledge of benthic habitats and diversity from Crozet and constitutes a baseline for further monitoring of marine communities for conservation strategies related to this part of the French Southern Territories National Nature Reserve.

Polar ecosystems are threatened by non-native plants, and this risk will increase with climate warming. Non-native plant growth depends on Antarctic environmental conditions and substrates, but these influences are poorly quantified. Under laboratory conditions we quantified the growth of Holcus lanatus, Trifolium repens and Taraxacum officinale across nine sub-Antarctic and Maritime Antarctic substrates with varying characteristics. This included, among others, variation in carbon (0.2–27.0%), nitrogen (0.03–2.1%) and phosphorus (0.04–0.54%) contents, under simulated Antarctic conditions (2°C) and a warming scenario. Legacy effects from an established non-native chironomid midge (Eretmoptera murphyi) and non-native grasses were included. H. lanatus and T. repens grew best in organic- and nutrient-rich substrates, while T. officinale growth was poorly correlated with substrate characteristics. Warming increased plant size by one to three times, but inconsistently across species and substrates, suggesting that climate change impacts on plant growth will vary across the Maritime Antarctic. A variable response was also observed in the legacy effects of E. murphyi, while non-native grasses increased H. lanatus and T. repens plant size, but not that of T. officinale. Plant growth was positively correlated with substrate organic and phosphorus content, and this information was used to trial a novel approach to identifying sites ‘at risk’ from plant invasions in the Maritime Antarctic.

This work provides a comprehensive examination of microplastic air pollution in Antarctica. Due to atmospheric microplastics’ emerging importance, analytical procedures and health effects are discussed. Microplastic pollution poses an increasing threat to the unique and delicate Antarctic ecosystem, potentially triggering harmful consequences not only for the local ecosystem and fauna, but also for human health and well-being, given the severe implications of microplastic pollution for global scenarios such as imminent worldwide warming and the melting of polar ice. Numerous investigations have now exposed the extent of microplastic pollution in the Antarctic and the prevalence of both nano- and microplastics in this region, a significant storehouse of the planet’s freshwater. This work also highlights the challenges of assessing the hazards that microplastics, particularly the nanoscale variants, may pose to human health and life maintenance. The results of this work suggest that global mechanisms of microplastic pollution mitigation are critical to microplastic transportation to the Antarctic reaches. This overview provides a better understanding of microplastic pollution in Antarctica while highlighting the urgency of more comprehensive research in this area to elucidate more precisely the short-, medium- and long-term effects of the arrival of these emerging contaminants in the Antarctic.

Penguins include 18 species of seabirds distributed in the Southern Hemisphere. Climate change is a growing problem that affects penguins, especially those living in Antarctica, making them some of the most currently endangered species. Loss of habitat, commercial fishing and infectious diseases spread by anthropogenic activities in the Southern Ocean are threats facing penguins. In addition, environmental changes affect the distribution of free-living species that act as intermediate hosts for parasites (e.g. krill, fish) and consequently their transmission dynamics and distribution. The present work aims to provide an update on macro- and microparasites recorded in all penguin species in wildlife. Based on published records from penguins, we provide a list of 157 parasite taxa recorded in all penguin species. The list includes 54 helminths, 45 arthropods, 39 bacteria and 19 protozoa reported in 207 scientific publications. Most papers were focused on the genus Spheniscus. In the analysis, we identify the distribution of parasites among hosts to better predict the disease risk facing their populations worldwide. Some pathogenic effects of the parasites found are discussed.

We report here an isolated insect forewing from Triassic deposits of the Eisenhower Range, northern Victoria Land, Antarctica. Based on the reduced venation (e.g. well-developed pterostigma, Rs dichotomously branched, Rs and M vein with five branches each), we tentatively identify the specimen as belonging to Permochoristidae (Mecoptera). However, due to incomplete preservation of the forewing, we prefer a determination under open nomenclature until more material of this taxon is available. The new specimen represents the first insect described from the Triassic of Antarctica and the first fossil record of Mecoptera in the continent, supporting the worldwide distribution and a greater diversity of the family during Triassic times.

Increases in atmospheric CO2 have led to more CO2 entering the world’s oceans, decreasing the pH in a process called ’ocean acidification’. Low pH has been linked to impacts on macroalgal growth and stress, which can alter palatability to herbivores. Two common and ecologically important macroalgal species from the western Antarctic Peninsula, the unpalatable Desmarestia menziesii and the palatable Palmaria decipiens, were maintained under three pH treatments: ambient (pH 8.1), near future (7.7) and distant future (7.3) for 52 days and 18 days, respectively. Discs of P. decipiens or artificial foods containing extracts of D. menziesii from each treatment were presented to the amphipod Gondogeneia antarctica in feeding choice experiments. Additionally, G. antarctica exposed to the different treatments for 55 days were used in a feeding assay with untreated P. decipiens. For D. menziesii, extracts from the ambient treatment were eaten significantly more by weight than the other treatments. Similarly, P. decipiens discs from the ambient and pH 7.7 treatments were eaten more than those from the pH 7.3 treatment. There was no significant difference in the consumption by treated G. antarctica. These results suggest that ocean acidification may decrease the palatability of these macroalgae to consumers but not alter consumption by G. antarctica.

As a result of analysis of the ice cover, geological structure and tectonics of the underlying rocks in the Lake Vostok area of Antarctica, a layered sub-horizontal structure of the ice cover and a distribution of the parameters of the ice composition were established. The physical and mechanical properties of the underlying rocks were determined experimentally. Complex tectonics revealed an increase in geothermal flow in the Vostok Basin region, which plays a role in the evolution of the Earth's crust and in shaping the morphology of its physical properties. A three-dimensional geomechanical model of the unified system ‘glacier-Lake Vostok-bedrock ’ was constructed and investigated. Regularities in the changes to the stress-strain state were revealed. Zones of development of plastic deformation in the ice cover along the perimeter of Lake Vostok and their distribution over the lake were established, which were confirmed by results from field observations. Modelling of geomechanical processes shows that the change in the mechanical state of the Earth's crust, taking into account the creep deformation of the ice sheet, relates more to nonlinear dynamic systems, which are characterized by unstable changes and should be considered as fractal systems.

A rock cairn, with two matchbooks buried beneath, was found on the summit of the highest hill on Thomas Island, Bunger Hills, East Antarctica. The matchbooks are most likely from United States World War II-era ration packs, which were distributed to various military and civilian expeditions from the mid-1940s into the 1950s. Bunger Hills was first visited by United States Navy ‘Operation Highjump’ in February 1947, when a seaplane most likely landed on a marine inlet, rather than a lake as reported previously. Thomas Island was first visited by United States Navy ‘Operation Windmill’ in January 1948, when a survey point was established, and it is probably this location that is marked by the rock cairn. The matchbooks were replaced beneath the cairn and the rocks replaced. Just over 76 years had elapsed between burial of the matchbooks, construction of the cairn and their rediscovery.

Antarctica is populated by a diverse array of terrestrial fauna that have successfully adapted to its extreme environmental conditions. The origins and diversity of the taxa have been of continuous interest to ecologists since their discovery. Early theory considered contemporary populations as descendants of recent arrivals; however, mounting molecular evidence points to firmly established indigenous taxa far earlier than the Last Glacial Maximum, thus indicating more ancient origins. Here we present insights into Antarctica's terrestrial invertebrates by synthesizing available phylogeographic studies. Molecular dating supports ancient origins for most indigenous taxa, including Acari (up to 100 million years ago; Ma), Collembola (21–11 Ma), Nematoda (~30 Ma), Tardigrada (> 1 Ma) and Chironomidae (> 49 Ma), while Rotifera appear to be more recent colonizers (~130 Ka). Subsequent population bottlenecks and rapid speciation have occurred with limited gene transfer between Continental and Maritime Antarctica, while repeated wind- or water-borne dispersal and colonization of contiguous regions during interglacial periods shaped current distributions. Greater knowledge of Antarctica's fauna will focus conservation efforts to ensure their persistence.

Marambio (Seymour) Island is located in the James Ross Archipelago east of the Antarctic Peninsula. Although several research groups have carried out studies on the biodiversity on the island for decades, surveys of bryophytes have not been developed. That is why there are currently only six species of mosses recorded in the northern part of the island. During the 2021–2022 summer Antarctic field trip, 15 mosses species were surveyed in Marambio Island. Of the total number of collected species, nine are reported for the first time for Marambio Island. For the remaining four species, their distributions are now expanded to Marambio Island.

Continuous permafrost is present across the McMurdo Dry Valleys of southern Victoria Land, Antarctica. While summer active-layer thaw is common in the low-elevation portions of the Dry Valleys, active layers have not significantly thickened over time. However, in some locations, coastal Antarctic permafrost has begun to warm. Here, based on soil and meteorological measurements from 1993 to 2023, we show that wintertime soil temperatures have increased across multiple sites in the Dry Valleys, at rates exceeding the pace of summer soil warming. Linear warming trends over time are significant (P < 0.05) at six of seven soil monitoring sites. Winter warming is strongly correlated with increased numbers of down-valley wind events (Foehn/katabatics), but it may also be driven by increased incident longwave radiation at some stations (although winter longwave increase is not significant over time). While down-valley wind events increase winter warming, when down-valley wind events are excluded from the record, winter soil warming remains persistent and significant, suggesting that Antarctic soils are experiencing less cold winters over time in response to regional warming. Together, these observations suggest that some Antarctic permafrost may be approaching a transition to discontinuous permafrost in some regions as winter freezing intensity is reduced over time.

Areas around western Vestfold Hills, East Antarctica, feature two sedimentary units in outcrops and excavations. Uppermost Dingle Sand is a gravelly, silty sand with boulders, which drapes bedrock ridges and more thickly covers valley floors and continues below modern sea level. Underlying Vestfold Beds are gravelly, muddy sands that are found in deeper valley fills. High-resolution aerial photography, topographic and bathymetric surveys, sediment grain size and field observations indicate that Dingle Sand formed as ablation till during the last deglaciation. Post-depositional modifications of Dingle Sand by decay of ground ice, mass movement, water, wind and marine transgression and regression have altered the texture, structure and fossil content in this region. Vestfold Beds are older, finer-grained tills. Indirect age estimation of Dingle Sand suggests deglaciation-age deposition with younger (Holocene) reworking in places, whereas Vestfold Beds may be as old as the Pliocene. These sediments post-date the early Pliocene Sørsdal Formation found on Marine Plain in southern Vestfold Hills. Identification of Dingle Sand as a separate, primarily glacial deposit helps clarify the glacial history of the Vestfold Hills. Evidence for marine modification of the deposits after deglaciation suggests that other regions might also have glacial deposits interpreted as marine because of post-depositional processes.

On an Antarctic research station, money is rendered useless, and essential material goods are imported from participating countries. Recognizing time as a valuable resource and acknowledging the existence of gift-giving practices, this article investigates the economic exchanges among members of an Antarctic expedition. Drawing on a 15 month ethnographic study conducted at the French Dumont d'Urville Station from November 2019 to January 2021, I analyse the gift of time and the exchange of services among the 24 members of the 70th expedition to Adélie Land, isolated for 8 months by the winter pack ice. The study presents an anthropological perspective on overwinterers, a population predominantly studied within the field of psychology, and examines the extent to which mutual aid and volunteering, which are often overlooked, shape interpersonal relationships and group dynamics. By exploring the ethnography of Antarctic time in relation to work and delineating various categories of service exchanges, we gain insights into individual motivations, causes, consequences and sanctions within the broader context of social relationships. I propose the hypothesis that the perpetual cycle of indebtedness among overwinterers plays a significant role in maintaining the smooth operation of an Antarctic station and fostering social balance within a winter crew.

Cape Welchness is an uncovered ice area on Dundee Island (north-east of the Antarctic Peninsula), mostly covered by Holocene-age glacial-glaciomarine deposits of up to 70 m in depth. In some areas, rocks from the Trinity Group and the Gustav Group outcrop. Syngenetic cryounits with an active layer development of 0.8 m and ice content ranging from 6% to 15%, increasing with depth, have been detected. Epigenetic units develop an active layer of up to 1.25 m (6–16% ice content), with similar depth values. Along the coastal zone, cryopeg reaches nearly 8 m in depth, alternating between ice, fresh water and saline water. The low and high plains exhibit extensive areas of open talik. In the low plain, a suprapermafrost summer aquifer with a thickness of 1.25–1.50 m develops. Glacial-fed creeks discharge 98% of the water input, while snow-fed creeks contribute only 0.04 Hm3/month. The ponds are divided into those fed by glaciers (linked to open talik) and those fed by precipitation (linked to closed talik). Creeks have an average salinity of 198 mg/l, lakes 190 mg/l and groundwater 223 mg/l. This study focuses on the area of the new Petrel Base, designed to enhance Argentine logistics.