Protecting animals from anthropogenic influences is important in vulnerable ecosystems such as Antarctica. A potential recent activity affecting Antarctic wildlife is the use of unmanned aerial vehicles (UAVs). Previous studies in this area have mainly focused on animal behavioural observations and have reported reactions to UAVs in many cases. To gain insights into the influence of UAVs on physiology (stress hormones) in addition to behavioural reactions, we conducted an experiment on chinstrap penguin chicks (Pygoscelis antarcticus) on the South Shetland Islands (Antarctica) during the breeding season of 2017–2018. Using a small quadcopter UAV, we performed flights over groups of penguin chicks in the early crèche phase using ‘Hard’ and ‘Soft’ treatment setups (15 and 50 m above the penguins, respectively). The behavioural observations revealed clear reactions to the UAV during the Hard treatment, but we could not find an association between such UAV activity and stress hormone levels. As we cannot clearly disentangle the effects of handling during blood sampling and the direct influence of the UAV, we conclude that the physiological impact of overflights at 15 m ranges from no impact to a maximum impact equal to the impact associated with animal handling. During the Soft treatment (UAV overflights at 50 m), no behavioural or physiological effects were detected.

We present a new 1:500 000 geological map of Alexander Island of West Antarctica. The map, combined with recent detrital zircon analysis, defines an updated chronostratigraphy for the Fossil Bluff Group, a Late Jurassic–Cretaceous forearc succession > 8 km in thickness that represents one of the most complete forearc successions globally. The forearc succession overlies and is in faulted contact with the LeMay Group, a late Permian basement accretionary complex that forms part of an extensive array of late Permian accretionary complexes in West Gondwana. The LeMay Group is intruded and overlain by a succession of Late Cretaceous–Palaeogene intermediate to silicic volcanic rocks and granitoid plutons. The uppermost unit on Alexander Island is an episode of Neogene to Quaternary basaltic volcanism associated with ridge-trench collisions and slab window development.

Monitoring snow depth in Antarctica is essential for understanding permafrost dynamics and soil thermal regimes. This study assesses the performance of low-cost, high-resolution, autocleaning ultrasonic sensors (MB7574-SCXL-Maxsonar-WRST7), powered by lithium D-type battery Geoprecision-Box dataloggers, in the South Shetland Islands. Traditional methods for estimating snow thickness, such as air temperature sensors in snow stakes, are economical but involve high maintenance costs and various complexities. To address these issues, we deployed ultrasonic sensors across 12 stations on Livingston and Deception islands from early 2023 to early 2024. Located at altitudes from 15 to 274 m above sea level and with varying wind exposures, these devices demonstrated notable durability and reliability, with only one sensor failure occurring due to structural damage. Data processing involved using an R script to filter out noise, and this process provided accurate hourly snow-depth measurements and revealed significant spatial and altitudinal variability, with depths ranging from 20 to 110 cm. Snow accumulation began in April and peaked in August and October, with major snowfall events contributing temporarily to snow depth but not to long-term accumulation. Our findings suggest that these sensors, as low-cost alternatives, could be integrated into networks such as the Global Terrestrial Network for Permafrost (GTN-P), supporting climate and permafrost studies.

Pygoscelis penguins are valuable indicators of the effects of rapid warming in the Antarctic Peninsula. In the western Antarctic Peninsula, Adélie penguins show a declining population trend, whereas gentoo penguins are expanding. The notably low reproductive success of Adélie but not gentoo penguins at Ardley Island during the 2023/2024 breeding season provided an opportunity to explore the potential effects of weather conditions and food availability as possible determinants of reproductive output. We explore associations between reproductive output, air temperature, wind speed, wind chill temperature and accumulated rain and snow. As a proxy for food availability, we used data of penguins’ foraging trips, which reflect krill abundance. A late-winter storm at the end of October 2023 led to a record-low wind chill temperature and sustained snow cover, negatively affecting the number of eggs that hatched successfully and/or the number of chicks that survived the first days after hatching. The effects were similar for both species, yet for gentoo penguins chick survival in the late stage of the chick-rearing phase was remarkably higher, possibly due to high food availability and a longer nestling period. As previously suggested, the greater plasticity of gentoo penguins may allow them to mitigate the negative effects of environmental variability, potentially explaining this divergent breeding success despite unusually harsh meteorological conditions.

This article explores the evolution of US policy on Antarctica, focusing on its legal, environmental and geopolitical aspects. It aims to identify changing US priorities in this regard. The Antarctic Treaty System (ATS) governs the region, emphasizing peace, scientific cooperation and environmental protection. The USA has issued four major memoranda on Antarctica in 1982, 1994, 2020 and 2024. This article highlights growing geopolitical competition, particularly with China and Russia. China frames Antarctica as essential to its global rise, using dual-purpose technologies that blur the line between science and strategic military interests. Similarly, Russia’s activities in the region raise concerns about potential violations of the ATS’s peaceful purpose mandate. The USA maintains its leadership in Antarctic diplomacy, advocating for environmental preservation and scientific cooperation. This article concludes by emphasizing the need for international collaboration to address climate change, resource exploitation and rising strategic tensions, ensuring Antarctica remains a region dedicated to peace and science.

The study of the ground surface temperature (GST) regimes from 2007 to 2021 at different stations on Livingston and Deception islands, South Shetland Islands, in the north-western sector of the Antarctic Peninsula (AP), shows that soils undergo similar cooling in early winter before a shallow snow mantle covers the sites. All monitoring sites along the study period go through seasonal phases of cooling, attenuation, insulation, fusion and zero curtain during winter, although thermal equilibrium is only reached at some stations located at lower elevations on Livingston Island. GST evolution at these stations and the duration of snow periods show oscillations, with turning points in the years 2014 and 2015, when temperatures were at their minimum and snow durations were at their maximum, in agreement with the cooling period occurring in the north-western AP in the early twenty-first century. The thermal regime is mainly controlled by snow cover and its onset and offset dates based only on descriptive patterns, not on statistical testing, more than by altitudinal, topographical, geological or geomorphological factors.

Volcanic monitoring in Antarctica provides dual benefits by facilitating the study of highly volcanically active yet underexplored regions and by serving as an essential tool for maintaining the safety of both national and international Antarctic bases. Deception Island, one of the most volcanically active areas on the Antarctic continent, is now equipped with an enhanced monitoring system, modernized by the Spanish National Geographic Institute (IGN), which assumed its management in September 2020, pursuant to a protocol established between the Spanish Ministry of Transport, Mobility, and Urban Agenda and Ministry of Science and Innovation. In order to meet the challenging conditions of the polar region, six permanent stainless-steel shelters have been installed over the course of the last four Spanish Antarctic campaigns. Each shelter is outfitted with batteries, solar panels, Wi-Fi and data acquisition systems for seismic and Global Navigation Satellite System (GNSS) stations. This monitoring network also comprises a station dedicated to measuring temperature within a thermal located where there is the anomaly on the island, a visual surveillance camera, seven seismic stations and six GNSS stations. All data collected are transmitted in real time to IGN headquarters in Madrid through Gabriel de Castilla Base, operated by the Spanish Army. Due to the growing volume of recorded data, it became necessary to upgrade transmission systems, leading to the installation of a next-generation satellite telemetry system during the 2023–2024 campaign. All seismic information is continuously and immediately analysed by the IGN’s National Seismic Network and is stored at the National Polar Data Center, housed within the Marine Technical Unit of the Spanish National Research Council, in accordance with the guidelines of the Spanish Polar Committee. The establishment of this infrastructure on Deception Island delivers a robust operational model that can be replicated in other polar settings, thereby contributing to the advancement of volcanic monitoring across the continent.

Microplastic release in Antarctica is an issue of increasing concern, despite the limited human presence in the region. This study estimates the annual release of microplastics from the wastewaters of scientific facilities through the use of personal care products and laundering. Furthermore, it analyses the most cost-efficient policy interventions to target this pollution. The study has estimated a potential release of 238 kg per year, which is negligible on a continental scale but could have substantial local environmental impacts. A comprehensive cost-efficiency analysis demonstrates that microplastic release can be effectively mitigated through low-cost preventative measures, such as installing washing machine filters and banning hygiene products containing microbeads. Furthermore, the implementation of wastewater treatment systems is suggested as a crucial and long-term cost-effective solution for treating wastewater effluent and removing other pollutants from the Antarctic region. These results provide a framework to inform policy decisions on microplastic release in Antarctica and lay the foundation for improved environmental protection strategies in this sensitive region.

Seabirds play an important role as top consumers in the food web and can be used as biomonitors for exposure to pollutants. Erythrocyte nuclear abnormalities (ENAs) represent one of the most important ways to detect genomic damage associated with environmental degradation and pollution. This study investigates the number of ENAs in three populations of two species of Leucocarbo shags. Blood samples from the Antarctic shag (Leucocarbo bransfieldensis) breeding on the Antarctic Peninsula and the South Shetland Islands and the South Georgia shag (Leucocarbo georgianus) breeding on the South Orkney Islands were analysed. The results revealed evidence of genomic damage in all individuals, with a mean number of ENAs of 26.54 and 43.51/10 000 red blood cells for Antarctic and South Georgia shags, respectively. Thus, the shags from the Orkney Islands showed a higher number of erythrocyte abnormalities, whereas no significant differences were observed among shag populations across the Antarctic Peninsula and South Shetland Islands. These results suggest that, in the northern part of the region, shags might be more exposed to pollutants. They also provide the first reference values for cytogenetic damage in this species and establish a critical baseline for future biomonitoring efforts.

Since 1994, the Andalusian Institute of Geophysics of the University of Granada group has been monitoring the seismic activity of Deception Island volcano (South Shetland Islands, Antarctica) during summer surveys. In this review, we analyse long-period and volcanic-tectonic events, including tremor episodes, recorded from 2011–2012 to 2021–2022 surveys with a local network and a seismic array. The seismo-volcanic activity on Deception Island occurs very locally, mainly as a result of tectonic destabilization induced by volcanic activity along with regional stresses, as a consequence of rifting and subduction processes spanning the South Shetland Islands, Bransfield Strait and Antarctica Peninsula. During this period, two changes to the volcanic alert level due to different volcanic parameters can be highlighted. The first of them was caused by the 2014–2015 seismic swarm as a consequence of a great regional perturbation located to the north-east of Deception Island, which spread around to the entire volcano. The second one, in the 2019–2020 survey, was established as a result of a significant increase in deformation parameters as a prelude of the August 2020 massive earthquake swarm that occurred in the Bransfield Strait, near the Orca submarine volcano. Furthermore, in the previous 2018–2019 survey, a peak of seismic activity was also recorded.

Antarctica, which has always been of great interest to researchers worldwide, is currently attracting considerable attention owing to climate change and other topics. In this context, bibliometric analysis allows the identification of hot topics, scientific productivity, cooperation, research gaps and strategic areas of potential interest. We conducted a bibliometric study to evaluate the global production of Antarctic research between 1980 and 2023 and analysed Spanish National Antarctic Programme (NAP) production as a case study. Scientific publications were reviewed and classified based on their main themes, key word co-occurrence and international collaborations. We found that scientific production worldwide and in the Spanish NAP has progressively increased since 1980. Globally, the main areas of research are the geosciences, oceanography and atmospheric sciences. However, the Spanish NAP, which reported 2287 publications, has focused more on the geosciences and ecology. Spanish Antarctic researchers have mainly collaborated with researchers from the USA, the UK, Germany and Italy. Our research highlights the importance of strengthening research plans to diversify and facilitate international collaboration, promoting a more interdisciplinary approach to address the current and future challenges identified by the scientific community. In this context, specific opportunities for developing a Spanish NAP strategic plan are discussed.

Marine microorganisms play a crucial role in biogeochemical cycles, especially in the surface microlayer (SML), which differs from adjacent subsurface waters (SSW). In this study, we sampled the SML and SSW at 20 sites along the western Antarctic Peninsula during the summers of 2015 and 2019, examining microbial, viral and environmental differences. We focused on phototrophic protists, specifically Phaeocystis-like species, known for their high dimethylsulphoniopropionate (DMSP) contents, which can be released through viral lysis. DMSP is a precursor to dimethylsulphide (DMS), a gas influencing Earth’s climate. We hypothesized a significant relationship between Phaeocystis-like abundance and DMSP concentration, with strong interactions with their specific viruses (V4) in the SML. Most biotic variables showed higher mean values in the SML, although these differences often were not statistically significant. DMSP concentrations correlated with Phaeocystis-like species abundance in both layers (R2 = 0.482, P ≤ 0.01; R2 = 0.532, P ≤ 0.01, respectively), whereas V4 abundance significantly correlated with Phaeocystis-like species only in the SML (R2 = 0.572, P ≤ 0.01). These results suggest stronger interactions between viruses and DMSP-rich hosts in the SML, potentially increasing DMS emissions to the atmosphere and impacting climate regulation.

The Southern Ocean remains one of the most data-deficient ocean basins despite its crucial role in global climate regulation. This study uses racing sailboats from the Barcelona World Race (2010/2011 and 2014/2015) and the Vendée Globe Race (2020/2021) as vessels of opportunity to collect sea-surface temperature and salinity measurements, offering a unique dataset for assessing oceanographic variability in this remote region. We conducted an inter-annual analysis of surface temperature and salinity anomalies relative to ARMOR-3D reanalysis and World Ocean Atlas 2023 climatological datasets, identifying regional patterns of change and variability. The results reveal a warming trend and general freshening of the Southern Ocean surface over the last decade, with the highest anomalies observed in the Indian and Atlantic sectors, whereas the Pacific sector showed the lowest anomalies in absolute terms. Notably, El Niño-Southern Oscillation (La Niña) and Southern Annular Mode phases played a significant role in modulating these temperature and salinity anomalies. This study underscores the scientific value of non-research vessels in monitoring climate-driven changes in Antarctic and sub-Antarctic waters, highlighting their potential to complement traditional observation networks in data-sparse regions.

The Bransfield Strait stands out as one of the most accessible places to study Antarctic submarine volcanism, hosting seven active principal submarine volcanic edifices (Edifices A, B and C, Three Sisters, Orca, Hook Ridge, G Ridge) and ~100 smaller seamounts. Only two of them have names (Eastern and Western Seamounts), and ~80 are grouped into two named areas: Spanish Rise and Gibbs Rise. During recent decades, numerous studies have assigned different names to the same volcanic edifices, leading to confusion. Only one of them, Orca, is formally registered in the Scientific Committee of Antarctic Research Composite Gazetteer of Antarctica, which is the catalogue collecting all of the official location names in Antarctica. A unified toponymy is essential, particularly to effectively manage regional logistic operations in case of eruption. Therefore, this study compiles the distinct names assigned to these edifices as a toponymy reference for future research. We recommend using the names most commonly cited in previous studies and, when new names are necessary, submitting them to the Scientific Committee of Antarctic Research Composite Gazetteer of Antarctica to avoid further confusion.

The use of seismic airguns has an environmental impact that is especially intense in relation to marine mammals. As a result, new techniques are being explored to replace or complement this tool. In this study, we test our ability to obtain seismic information about the shallow seafloor structure using fin whale songs as an alternative seismic source. We analyse data collected by ocean-bottom seismometers deployed around Orca volcano in the Bransfield Strait, Antarctica, in 2019. We detected fin whale calls and designed an algorithm to calculate their locations and origin times. We used a relative approach to reduce location uncertainty based on the similarity of waveforms between consecutive calls. We were able to calculate the trajectory of a fin whale that crossed over Orca volcano. Strikingly, the whale path coincided partially with a multi-channel seismic profile carried out with airgun shots. This coincidence allowed us to investigate the performance of the whale calls as seismic sources, comparing them to the almost co-located airgun profile. We constructed receiver gathers using both whale calls and airgun shots. The main features of the whale call sections are consistent with the results obtained using the airgun source. We conclude that although this method has some drawbacks, such as the unpredictable behaviour of whales and the smaller power and lower resolution capabilities of the whale calls compared to the airgun surveys, it is still a feasible alternative as a complement for active-source seismic studies in the marine environment.

Leopard seals (Hydrurga leptonyx) lead solitary lives, mainly associated with sea ice, and they are parasitized by the sucking louse Antarctophthirus ogmorhini, one of the few known marine insects and probably the only group adapted to survive in deep-ocean environments. A challenge for seal lice is that their eggs do not survive underwater, requiring them to complete their life cycle during the host’s reproductive or moulting season. We investigated the infestation parameters of A. ogmorhini in leopard seals on the Danco Coast, Antarctic Peninsula, estimating prevalence and mean abundance, comparing by sex, age class and interannual variability and determining the relationship between these parameters and the body condition of the seals. Over four field seasons (2014, 2015, 2019 and 2020), we collected data from 50 seals: 12 females and 38 males, including 47 adults and 3 juveniles. The overall prevalence (14%) was the lowest recorded for an Antarctic seal, with higher rates in juveniles (33.3%) than adults (12.8%) and in males (15.8%) compared with females (8.3%). Generalized linear models analysis, considering body condition and interannual variability, did not reveal a strong correlation between body condition and lice infestation. Although no strong correlation was found, there is some indication that seals in poorer condition may be more heavily infested.

We evaluated the physiological condition of the Pygoscelis penguins at Isla 25 de Mayo/King George Island (Antarctica Peninsula). Samples were collected from adults and chicks of Adélie (Pygoscelis adeliae, n = 20 each), gentoo (Pygoscelis papua, n = 20 chicks and n = 24 adults) and chinstrap penguins (Pygoscelis antarcticus, n = 18 each). We analysed haematological and biochemical parameters as indicators of health, immune response and nutrition. Gentoo penguin chicks exhibited higher haematocrits, indicating development linked to erythropoiesis and reticulocyte release from bone marrow or signalling dehydration related to fasting periods in chicks. Adélie penguins had increased total leukocyte counts, basophils and eosinophils, whereas gentoo penguins showed elevated heterophils and decreased lymphocytes, resulting in a higher heterophil/lymphocyte ratio stress index, possibly due to the impact of human activities. Chinstrap penguins from a remote area exhibited the lowest heterophil/lymphocyte ratio values. Adélie penguins showed more erythrocytic nuclear abnormalities, indicating sensitivity to environmental deterioration due to human impacts. The biochemical results were less consistent; Adélie penguins had higher cholesterol, whereas gentoo penguins had elevated triglycerides. Gentoo penguins showed dietary adaptability based on prey availability in this area. Our findings highlight the vulnerability of Adélie penguins and contribute to a 20 year physiological monitoring dataset for Antarctic penguins, which will aid future comparative studies.

The numerous ephemeral glacial meltwater streams that flow during the summer in the McMurdo Dry Valleys of South Victoria Land, Antarctica, provide habitats for microbial mats. One of the common mat types is composed of Chlorophyta (colloquially known as a ‘green mat’ due to its colour). While the presence of these mats is regularly monitored, their taxonomic makeup is still under investigation. Using 18S rRNA gene sequencing, the composition of the chlorophyte-dense mats from between rocks and in the main channel from several streams across two valleys was examined. Samples were maintained in native stream water, and select samples from representative locations were transferred to Bristol Medium. The appearance of other eukaryotic species - diatoms and tardigrades - in these green mats completed this integrated study. The results show that the relative abundance of Chlorophyta was significantly increased with the introduction of inorganic nitrogen from Bristol Medium. Chlorophyte taxa in the Hazenia and Pleurastrum genera dominated the samples across both sample types (rock or exposed) and treatments (Antarctic water or Bristol Medium). Furthermore, a reduction in overall sample diversity was observed in samples in Bristol Medium, suggesting preferential nitrogen utilization by these chlorophytes.