Understanding how human activities affect Antarctic ecosystems is essential for both environmental management and the interpretation of ecological change. This is particularly important in Antarctica’s ice-free areas, which contain most of the continent’s terrestrial biodiversity and host the majority of scientific infrastructure. While work has been done to understand short-term impacts of research stations and scientific activity, little is known about the persistence of these impacts on soil ecosystems. Here, we examine the long-term ecological legacy of historical research infrastructure in the McMurdo Dry Valleys, East Antarctica. We collected soil samples from sites of historical research facilities that have since been removed, extracted and identified soil invertebrates and conducted statistical and geospatial analyses to identify spatiotemporal trends and evaluate patterns of abundance relative to distance from disturbance centres and time since abandonment. Soils closer to former infrastructure consistently had lower nematode abundances than soils further away, indicating long-lasting impacts of human activities on soil ecosystems. We also found evidence of potential recovery in some nematode populations, which appears to depend on the type of disturbance and the surrounding environmental setting. At several sites, surface disturbance from historical infrastructure is no longer readily apparent but biological recovery remains incomplete, demonstrating that visual restoration of the landscape does not necessarily correspond to ecological recovery. Measuring the impacts of human activities in these areas is important because they may confound our ability to interpret the subtle but significant effects of climate change and ecosystem responses more generally. This is particularly pressing as research and tourism are expected to increase in these regions. We offer ecological explanations for these patterns and discuss their implications for environmental management and conservation in the McMurdo Dry Valleys and other ice-free areas of Antarctica.

Blood Falls is a unique feature that appears at the snout of the Taylor Glacier in the upper Taylor Valley, East Antarctica. It is an iron-rich brine that occasionally gets expulsed from a subglacial source due to the weight and movement of the overlying glacier. The brine that emanates stains the glacier as it oxidizes at the surface and flows towards the West Lobe of Lake Bonney (WLB). Recent work (Spigel et al. 2018, Lawrence et al. 2020) has shown that, besides the Blood Falls contribution, the brine enters the WLB all along the front of Taylor Glacier, creating cold water anomalies at the depth where this subglacial brine’s density is matched by the surrounding lake water. Mikucki et al. (2015) detected substantial brine at the base of Taylor Glacier using an airborne transient electromagnetic sensor. Badgeley et al. (2017) used radio echo sounding to delineate the brine further and to show that there are subglacial flow pathways that direct the brine to the centre and south side of Taylor Glacier’s snout, in addition to what flows from Blood Falls.

Reproductive synchrony is common in populations that inhabit seasonal environments where reproductive timing is important to offspring survival. Weddell seals (Leptonychotes weddellii) reproduce in strongly seasonal Antarctic environments and are known to exhibit reproductive synchrony that varies by latitude, whereby more southerly populations give birth later. The Erebus Bay population of Weddell seals is the southernmost mammal population in the world, and birth-date synchrony has been demonstrated in this population. Various life history correlates including sex, maternal age and reproductive status have been identified as predictors of birth timing, but all prior work has been done on pups born to locally born mothers. Immigrant females originating from unknown sites in more northerly locations also produce pups in Erebus Bay and may have different birth timing due to the earlier average birth dates in their natal colonies. Using 22 years of capture-mark-recapture data for Weddell seals in Erebus Bay, we aimed to assess whether the timing of birth dates for pups born to immigrant mothers differs from that of pups born to locally born mothers. To our knowledge, this is the first time that such a comparison has been studied in a wild population. Birth dates were examined using Bayesian linear regression. We analysed birth dates from 7539 pups (4932 from locally born mothers, 2607 from immigrant mothers) born to 2210 mothers (1254 locally born, 956 immigrant) and found that there were no biologically impactful differences in the birth dates of pups born to locally born or immigrant mothers. Additionally, birth-date patterns for immigrant mothers were similar to those for locally born mothers with respect to various traits. Our results demonstrate that immigrant Weddell seal mothers can synchronize birth timing with locally born mothers. More research is required to understand the underlying mechanisms that allow for immigrant seals to achieve birth-date synchrony.

Antarctic ice-free coastal environments, like the Vestfold Hills (East Antarctica), are shaped by a complex interplay of physical processes. This study synthesizes new data and existing research from the Vestfold Hills across marine, terrestrial and cryosphere science, meteorology, geomorphology, coastal oceanography and hydrology to explore interconnected processes ranging from icescape morphology and sediment transport to ocean-floor scouring and ocean-atmosphere interactions. Coastal landforms and habitats result from the interaction of marine dynamics with the aeolian and fluvial transport of glacially derived sediments and geomorphic features. Rocky shorelines dominate the region, and extensive fjords are prominent coastal features, whereas intertidal sediments and beaches are scarce. The marine environment is characterized by slow currents, low-energy waves, annually variable land-fast ice, irregular sedimentation rates and a geomorphologically complex shoreline. Aeolian and fluvial sediment deposition into coastal waters and onto sea ice can significantly impact local ecological and physical processes. Human activity further modifies these dynamics. Ice-free coastal areas such as the Vestfold Hills are predicted to experience substantial environmental shifts due to climate change. Wind speeds, temperature and precipitation are increasing in the Vestfold Hills. Retreating grounded ice sheets are likely to expand this coastal area and increase meltwater and sediment inputs into nearshore marine systems. Concurrently, changes in sea-ice extent, thickness and/or duration may profoundly alter the structure and function of this coastal environment.

The diet of Antarctic toothfish (Dissostichus mawsoni) captured by bottom longlines on the Ross Sea continental shelf was examined during four consecutive summer research surveys (2012–2015) within the Ross Sea polynya. The surveys included three areas: south-west continental shelf (Core area), McMurdo Sound and Terra Nova Bay. Toothfish diet comprised mainly small notothens, especially Trematomus spp. (which accounted for 20–52% of total prey weight by area) and icefish (30–57% of total prey weight by area). Notothen prey were mainly Trematomus loennbergii, with Trematomus scotti regularly observed. The most important icefish prey were Chionodraco spp., of which Chionodraco hamatus was most frequently identified, and Neopagetopsis ionah. Dragonfish (Bathydraconidae) were rarely observed, except in 2012 when Gymnodraco acuticeps accounted for ~11% of prey weight. Antarctic silverfish (Pleuragramma antarcticum) were regularly observed but contributed little by weight (0.4–3.6% total prey weight by area). Invertebrates were a relatively small component of toothfish diet, with the prawn Notocrangon antarcticus and the amphipod Eusiris spp. found in ~3–24% and 0–9% of stomachs, respectively, but they were small and weighed little. Icefish (particularly Dacodraco hunteri) were more important than notothens in toothfish diet in Terra Nova Bay. The results indicate that D. mawsoni are predominantly benthic feeders, with no evidence of substantial feeding away from the seafloor in the days before they were caught. In contrast with previous McMurdo Sound diet studies, Antarctic silverfish were of relatively minor importance as a prey item for Antarctic toothfish in other areas of the Ross Sea shelf, which is consistent with a coastal and fast-ice distribution of silverfish and/or a seasonal change in the distribution of silverfish.

Here we describe a new springtail species found on Byers Peninsula, Livingston Island. The new species, Folsomotoma punctata, is known from sub-Antarctic South Georgia, but this is a first occurrence of this species for the South Shetland Islands and the Maritime Antarctic, increasing the total species number to 15. Considering the widespread distribution of F. punctata across Byers Peninsula, it seems most likely that this species has been present for a long time. That it was only now reported reflects the limited arthropod surveys conducted in this region of the South Shetland Islands, and highlights the need for more thorough and high spatial resolution systematic surveys across different vegetation and habitats to better understand the terrestrial biodiversity patterns in Antarctica.

The finding of an incorrect non-Antarctic locality assigned to a specimen of Trematomus loennbergii at the Natural History Museum, London, led to the discovery of two (of three) syntype specimens, previously considered missing, of this species. The third syntype, a larger specimen in better condition, is designated as the lectotype of T. loennbergii; the two newly discovered specimens, re-identified as Trematomus pennellii, become paralectotypes.

Census counts of Pygoscelis penguins on the Antarctic Peninsula and Scotia Arc are conducted both regularly around field stations and opportunistically from ships with the goal of assessing the breeding abundances and trends of these indicator species. Regional trends and abundances are often more policy-relevant than population-specific metrics, but survey patterns in the area have not been planned to optimize regional inference. We evaluated the ability of several monitoring schemes to describe regional trends and abundances of Pygoscelis penguins. Using a ‘pseudo-true’ time series as a starting point, we simulated time series of ‘observed’ census data for the period of 2000–2024. We then fit a hierarchical Bayesian population model to each dataset to assess how well each monitoring scheme recovered the known regional trends and abundances. Simulations were repeated across combinations of survey efforts, variances in inter-population abundances and census uncertainties. We found that implementing structured monitoring schemes would improve our ability to recover regional trends and abundances compared to the actual distribution of surveys conducted during the 2000–2024 period. For scenarios characterized by low variance in abundance such as the gentoo penguins on the central-west Antarctic Peninsula, we could recover trend and abundance estimates with considerably less survey effort if we deployed a monitoring scheme that cycled through all populations at an equal interval. For scenarios characterized by high variance in abundance such as the Adélie penguins on the north-east Antarctic Peninsula, surveys were optimized by splitting effort between satellite monitoring of the largest populations and cycling through the other populations. These findings are strongly influenced by the rapid increase in uncertainty regarding population abundance in the seasons after a census count, highlighting the importance of prioritizing sites where abundances are highly uncertain due to long intervals since the last survey.

Emperor penguins are highly reliant on stable fast ice for successful breeding, and some studies project possible quasi-extinction for most colonies by 2100 due to future sea-ice loss. To better understand the future response of emperor penguins to ocean-climate warming and the possibility of major changes to their habitat, it is essential to better understand how colonies have responded to past changes in ice conditions. In this study, we identify the historical locations of the SANAE, Astrid and Mertz colonies in all available Landsat 4–9, Advanced Spaceborne Thermal Emission and Reflections satellite (ASTER) and Sentinel-2 imagery for the period 1984–2024. We record the location and surface type of the colonies’ breeding locations each year while also recording major calving events, early fast-ice breakouts, distance to the fast-ice edge, and colony location span within a season. The results show that colonies usually return to approximately the same sites annually, but we observe variations due to major calving events. Following such events at Mertz (2010) and SANAE (2011), colonies relocate to different sites, where they may be more vulnerable to early fast-ice breakout or must travel longer distances to the fast-ice edge. In subsequent years, the colonies eventually return to sites close to their original location. Additionally, we observe early fast-ice breakouts that may impact breeding success at Mertz and SANAE colonies, including as early as September at Mertz (2016). Such breakouts coincide with both broader sea-ice lows and variations in colony location. Furthermore, all three colonies move onto the adjacent ice shelf in some years (and at Astrid and Mertz, also icebergs), including when stable fast ice is available, suggesting that this behaviour may be more common than previously thought. Observation of these behaviours contributes to broader understanding of emperor penguins’ adaptability and will aid future efforts to model the response of the species to ice loss.

Poikilothermic and short-lived drifter species such as zooplankton are highly responsive to climate-driven changes and frontal systems in the Southern Ocean. To understand these changes, ongoing assessment of zooplankton is essential. Changes in abundance, biomass and species composition of zooplankton in the Indian sector of the Southern Ocean were assessed during the austral summer of 2022/2023 using a ring net that was towed obliquely from an average depth of 200 m to the surface. Thirty-six zooplankton taxa were identified at seven stations, with copepods constituting 64% of the population across 23 species. Zooplankton abundance and biomass were higher in Transect 2 (60–64°S) compared to Transect 1 (50–54°S). A cluster analysis revealed four zooplankton community groups. Notably, the distribution patterns of non-copepod taxa appeared to be influenced by diel vertical migration behaviour, which was closely tied to seasonal dynamics and the timing of sampling. This study improves our understanding of how different oceanographical fronts and behavioural patterns shape zooplankton communities in the Southern Ocean, emphasizing the need for improved sampling to include smaller zooplankton species and to better resolve temporal dynamics.

The diverse cutthroat eel family Synaphobranchidae comprises 13 genera and 57 species of mostly deep-sea fishes documented from all oceans. Here, we report on the catch of a single synaphobranchid specimen in the Kong Haakon VII Sea off Dronning Maud Land, representing the first record of the genus Ilyophis in the Southern Ocean. The specimen was trawled at a depth of 1500 m during the 2019 joint expedition of the Norwegian Polar Institute, Institute of Marine Research (Norway), the University of Bergen (Norway), the Arctic University of Norway, the University of Science and Technology (Norway) and the Stellenbosch University (South Africa) onboard the Norwegian research vessel Kronprins Haakon. The specimen is deposited in the ichthyological collection of the University Museum Bergen. In this study, we tentatively identify the specimen as Ilyophis cf. maclainei based on an integrative taxonomic approach. Phylogenetic analysis of mitochondrial partial cytochrome oxidase I places the Antarctic specimen in a clade of sequences deposited in Barcode of Life Data System (BOLD) as Ilyophis sp., Ilyophis cf. brunneus and Ilyophis brunneus. Morphological data show overlaps in some morphometric and meristic characters with I. brunneus and the recently described I. maclainei - with no genetic samples currently being available for the latter. Our analysis reveals taxonomic issues within I. brunneus and the need for increased sampling and a worldwide taxonomic revision of I. brunneus. The full mitochondrial DNA of the Antarctic specimen is reconstructed as a resource for future research.

This bibliometric study maps Antarctic microbiology research in South American countries using Web of Science records (1978–2024). A descriptive, quantitative design applied bibliometrix and VOSviewer, with thesaurus-based normalization reducing keyword variants by 6%, to construct a 1240-term science map. After manual screening focused on Antarctic (excluding sub-Antarctic) microbiology, 497 publications remained. Chile led the output (234), followed by Brazil (124) and Argentina (98). The leading journals for this output are Polar Biology, Frontiers in Microbiology and Extremophiles. Keyword and co-occurrence analyses revealed dominant themes of Pseudomonas and the bioremediation/biodegradation of heavy metals. The largest cluster, centred on Pseudomonas, was linked to oxidative stress, antioxidants, pigments, biofilms and polyhydroxyalkanoates, with a second major cluster focused on bioremediation. The findings indicate an applied orientation towards collecting biological materials and characterizing molecular/biochemical properties with commercialization potential. This study clarifies trends and gaps, informing future directions to facilitate international cooperation and advance the understanding of microbial diversity and functions across Antarctic habitats.

Dry permafrost underlain by ice-cemented permafrost has been reported in several locations in Antarctica. Initially thought to be relic ice, it is now understood that this subsurface ice is in equilibrium with the surface conditions, although it is not in equilibrium with the atmosphere. We use year-round data from University Valley in the Dry Valleys and Elephant Head in the Ellsworth Mountains to investigate the seasonal variations in water vapour flux that control the depth to the ice table under dry permafrost. Our analysis shows that the mean annual water vapour density of the soil surface exceeds the atmospheric value by a factor of up to ~2 due to summer snow. The attenuation and phase shift of the annual temperature cycle with depth result in colder temperatures at the ice table than at the surface of the soil in summer. We conclude that this temperature gradient, combined with the summer snow, provides the flux of water to the ice table necessary to maintain the ice. In University Valley, reducing the snow days by 40% moves the stability depth of the ice table from 42 to 66 cm. Increasing the snow days by 60% shifts the ice table to 17 cm. These variations can explain the observed gradient in the depth to the ice table in University Valley.

Located in the central part of the Western Antarctic Peninsula, the Argentine Islands-Kyiv Peninsula region is a hotspot of moss diversity, with 51 species and one variety currently known. However, no studies have specifically addressed the distribution of rare mosses in this region. Applying the only definition of moss rarity currently available for Antarctica, we identify very rare (one to two unique occurrences) and rare (three to five unique occurrences) moss species in the region and present a biogeographical analysis of their spatial distribution with corresponding maps, based on a comprehensive synthesis of archival published occurrence data. Of the 51 recorded species, 23 were classified as locally very rare or rare. Cape Tuxen, Galindez Island, Darboux Island and Cape Pérez hosted the highest concentrations of rare moss diversity, with eight, seven, seven and six species, respectively. Five rare species were recorded at Petermann Island, four at Booth and Lahille islands and three each at Diorite, ‘Eight’ and Uruguay islands. Additionally, several locations hosted species with unique characteristics, including their only known occurrence in the Antarctic Peninsula or at their known range edge. Very rare and rare species assemblages showed only partial overlap among sites: the four most species-rich sites shared several taxa, but no species occurred at all sites. Uruguay, Diorite and ‘Eight’ islands together represented a full moss species pool of the four most species-rich sites. In addition, some sites supported distinct species not recorded elsewhere in the region. Notwithstanding the limitations of the available survey data, these findings highlight the regional significance of the Argentine Islands-Kyiv Peninsula region within the Western Antarctic Peninsula for moss diversity in terms of the recognized criteria required for developing proposals for formal protection under the Antarctic Treaty.

The highest-elevation and a far southern pond in the Transantarctic Mountains is briefly documented. The small pond, at an elevation of ~2350 m, was frozen when it was visited in the 1963–1964 field season, and satellite imagery suggests it has remained frozen since 2010. A second frozen pond is noted, but its precise location is uncertain.

Maritime Antarctica experiences less extreme environmental conditions than much of the Antarctic continent and has further been impacted by considerable warming in recent decades. While inventories exist of macroscopic Antarctic biodiversity, and there is some information available on culturable microorganisms, much less is known about the presence of other cryptic eukaryotic organisms. DNA metabarcoding provides a method for assigning the DNA of multiple different organisms simultaneously from environmental samples. In this study, we used DNA metabarcoding to investigate the environmental DNA (eDNA) diversity of non-fungal eukaryotic organisms associated with rocks in the South Shetland Islands. Five sampling points were selected from a stratigraphic profile at Mazurek Point, King George Island. Collected rock samples were pulverized, total DNA was extracted and amplicons were generated using ITS2 primers, then these were sequenced using an Illumina MiSeq system. Sequences representing five kingdoms and nine phyla were retrieved. Viridiplantae was the most diverse and abundant group, with 42 assigned taxa, followed by Chromista, with 22 assigned taxa. The precise lithology did not influence the assigned diversity. The majority of assigned taxa are widespread and plausibly present in the area, but some are not known from Antarctica, including some from tropical regions. The latter assignments probably result from the limitations of the databases used, although in some cases they may indicate evidence of anthropogenically associated or naturally dispersed DNA-containing material.

To date, there are few records of Holocene changes in sea ice in the south-eastern Weddell Sea, which limits our understanding of how sea ice has interacted with climate in this sector of the Southern Ocean. Here, we present a multi-proxy analysis of a snow petrel stomach-oil deposit that records occupation history and dietary fluctuations from ~1800 to 800 calibrated (cal.) yr bp. Lipid biomarkers (fatty acids (FAs), sterols and alkanols), bulk stable isotopes (δ13C and δ15N) and trace elements show distinct dietary shifts, which are linked to centennial-scale changes in summer sea-ice extent. From ~1730 to 1370 cal. yr bp, foraging in pelagic waters near the edge of the sea-ice pack is suggested by low nest occupation rates and Antarctic krill contributions to the diet. From ~1370 to ~1180 cal. yr bp, an increase in nest occupation and a fish-dominated diet reflect foraging within open water (polynyas) during a period of more extensive summer sea ice. A decrease in nest occupation after ~1180 cal. yr bp is attributed to local sea-ice readvance, resulting in reduced access to open water, impeding foraging success. Our results highlight the use of multi-proxy geochemical records from snow petrel stomach-oil deposits to reconstruct seasonal sea-ice fluctuations in the Weddell Sea and their interactions with late Holocene climate records.