Abstract This review considers the current status, and highlights existing knowledge gaps, on Antarctic terrestrial and freshwater biological responses to climate change. Climate change is considered to be one of the major drivers of future ecosystem change in Antarctica. Understanding the biological responses, and associated shifts in biodiversity patterns, biotic interactions and processes, that are likely to occur under continued climate change is fundamental for predicting its consequences for the functioning of Antarctic ecosystems. However, quantifying changes in species abundance, biodiversity, community composition and biotic interactions, and how these are influenced by variations in a multitude of environmental variables, is challenging. All biological groups in the Antarctic terrestrial and freshwater domains currently show low species richness at higher latitudes, indicating that there should be scope for lower-latitude species to expand their distributions southwards under warming conditions. The northern, ‘trailing edge’ or lower altitudinal limits may also shift southwards or upwards, respectively. However, to date, only one report exists of increased diversity within field experimental warming studies, and none exist from the few available long-term monitoring sites. Similarly, while notable plant-cover expansions have been recorded at some localized sites, no clear large-scale vegetation response has been documented within recognized Antarctic biological regions, while organisms living within the vegetation show highly variable responses. There are still many knowledge gaps on this matter for various biological groups across and within Antarctic regions. While it is frequently posited that the potential for climate change-driven range expansion and biodiversity shifts is substantial, the biological responses reported to date indicate that current levels of climate change have not (yet) resulted in large-scale changes in abundance and biodiversity patterns across Antarctica.
Although polar fungi Pseudogymnoascus spp. are known to produce specialized metabolites (SMs) with wide-ranging potential for the pharmaceuticals industry, there is limited knowledge on the biosynthetic gene clusters (BGCs) involved. Therefore, this study aims to search for BGCs based on the whole-genome sequences (WGSs) of Antarctic Pseudogymnoascus griseus (strain AKSP4) and Arctic Pseudogymnoascus australis (strain HNDR4) that were sequenced with the Illumina NovaSeq6000 platform and assembled de novo. The genome size produced for P. griseus (strain AKSP4) was 35.6 Mb with 2172 contigs, whereas the genome size produced for P. australis (strain HNDR4) was 32.0 Mb with 586 contigs. Totals of 58 and 51 BGC regions were predicted for P. griseus (strain AKSP4) and P. australis (strain HNDR4), respectively. Four putative regions were found to be similar to those of choline, swainsonine, trichobrasilenol and geodin, which have antibacterial, anticancer and insecticidal activities that are valuable for the biotechnological industry. The BGCs reported here could potentially help narrow down the gene regions to be investigated for the characterized SMs of interest and elucidate their biosynthetic pathways. Furthermore, the WGSs produced provide useful reference genomes for assembling other polar Pseudogymnoascus strains. The present study is the first to report the occurrence of P. australis within the Arctic region. Overall, this study highlights the potential of polar fungi and their genomic information as sources for novel compounds in the biotechnological industry.
Understanding the diverse pathways between science and policy is crucial for assessing the impact of research. In this context, 'research impact' refers to the broader societal benefits of scientific research that extend beyond traditional research evaluation metrics. Metrics of academic and scientific excellence, such as h-indexes or bibliometric analyses, often fail to capture the impact of science on policy. To investigate one aspect of how research can influence policy, and therefore probably have impact, this study analysed ice core publications from the Australian Antarctic Program. A dataset of 266 Australian-authored and/or -funded East Antarctic ice core publications was examined, revealing that 123 were cited in 284 international and Australian (domestic) policy and policy-related documents. To analyse the policy influence of the research, key information was categorized into authoring countries, institutions, research themes and the contextual use of publications by the documents. This categorization highlighted the different uses of information and interpretations of ice core publications by separate forums, with some more active compared to passive uses. The 'Active-Passive' spectrum developed in this study provides a framework for understanding how research is being used, and it underscores the relevance of ice core science to local Australian governance. The results show that domestic uptake of ice core publications by some Australian states demonstrated more 'Active' inclusions in policy to support an area of national interest: water security. The mixed methods piloted in this study can be used to assess scientific publications from national Antarctic programmes with more nuance, thereby offering an improved avenue for measuring research impact.
In 2019 we collected gravity and magnetic measurements, in conjunction with multibeam swath bathymetry and multi-channel seismic reflection profiling, to characterize the neovolcanic zone around Orca Volcano in the Central Bransfield Basin, Antarctica. New analysis of mafic dredge samples shows that the caldera is composed of rocks with a wide range of measured susceptibilities. Multi-channel seismic reflection profiles across Orca Volcano showed the presence of several reflectors under the caldera, characterized by strong amplitudes and phase-reversed polarity. Gravity and magnetic data also show coincident anomalies. Our 2D forward modelling shows that these anomalies are the result of a shallow magma accumulation zone underlain by a low-density, low-susceptibility volume. We also observe that the axial ridge to the south-west of the volcano is characterized by a narrow zone of low density and high susceptibility, consistent with a focused rift axis. To the north-east of the volcano, the potential field data show that the axial rift is left-lateral offset and is somewhat broader. An asymmetric pattern of decreasing density and susceptibility of igneous rocks across the rift is consistent with a pattern of extension that has only recently evolved into a narrow rift and the mid-ocean ridge basalt-like compositions seen in dredge samples. These results are consistent with rifting that is rapidly transitioning to seafloor spreading.
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 similar to 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 similar to 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.
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 Ad & eacute;lie 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.
Human activity in the Antarctic is supported by a wide network of government agencies, policies, businesses and workers back home. This polar workforce is particularly important in the so-called 'Antarctic gateway cities', which foreground their economic and cultural connections with the far south. Rather than focusing just on the Antarctic continent as the place of work, this paper therefore takes a broader approach by turning attention to the people back home that enable Antarctic logistics, modelling, policymaking and public awareness to be executed successfully. The paper outlines a matrix for mapping polar work capacity, with Antarctic roles classified as direct or indirect and as in situ or ex situ. By bringing together stakeholders from a range of Antarctic workplaces (including local and national government, academia, tourism and local business owners and training providers) from Christchurch (New Zealand) in October 2024, a workshop event identified the key challenges facing the Antarctic sector over the coming 5 years and highlighted areas where international collaboration could help to address these challenges into the future. Key suggestions include the implementation of an overarching Antarctic strategy; training and education to improve local talent and pathways; enhanced visibility of existing skillsets; establishing exchange opportunities across the Antarctic gateway cities; and developing Antarctic identities, including through tourism opportunities.
The intensity and frequency of extreme weather events in rapidly changing environments continue to increase, driving unusual behaviours and posing significant threats to terrestrial ecosystems. In this study, we describe the co-occurrence of 1) Collembola swarming, 2) vegetation die-off and 3) extreme weather events, particularly heavy rainfall and high temperatures, over a 5 day period on sub-Antarctic Marion Island. Taxonomic and molecular evidence confirmed that the Collembola species displaying swarming behaviour was Ceratophysella denticulata, an invasive hypogastrurid. Our observations suggest that environmental stressors may have induced vegetation die-off, which, in turn, may have directly or indirectly driven Collembola aggregation. The association of these factors highlights the potential role of Collembola as bioindicators of soil ecosystem responses to climatic extremes, and that the recognition of these interactions can be critical in the prediction and management of ecological responses to changing environments.
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.
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 similar to 1800 to 800 calibrated (cal.) yr bp. Lipid biomarkers (fatty acids (FAs), sterols and alkanols), bulk stable isotopes (delta C-13 and delta N-15) and trace elements show distinct dietary shifts, which are linked to centennial-scale changes in summer sea-ice extent. From similar to 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 similar to 1370 to similar 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 similar to 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.
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.
The Fremouw Formation of the Central Transantarctic Mountains preserves the southernmost record of Early to Middle Triassic terrestrial ecosystems that developed in the aftermath of the end-Permian mass extinction. Although the well-studied vertebrate fossil assemblage in the lower member of the Fremouw Formation provides a detailed snapshot of subpolar ecosystems immediately following the end-Permian mass extinction, the nature of how long these earliest Triassic communities persisted at the southern extremes of Pangaea is virtually unknown. Importantly, the timing and extent of the major faunal turnover between the lower and upper members of the Fremouw Formation have been obscured by the paucity of fossil specimens historically recovered from the middle member. Here, we describe the first vertebrate assemblage from the middle member of the Fremouw Formation, including occurrences of procolophonids (including Procolophon trigoniceps) and archosauromorphs (including Prolacerta broomi), as well as infilled vertebrate burrow casts referrable to the ichnogenus Reniformichnus. We also summarize and expand on lithostratigraphic shifts between the lower, middle and upper members of the Fremouw Formation. Although the sample size of vertebrate body fossils is small compared to the lower and upper members of the Fremouw Formation, we discuss the evidence for a taphonomic shift between the lower and middle members of the Fremouw Formation that favours preservation of smaller-bodied taxa and individuals in the latter. Together, these preliminary data add crucial context to the persistence of subpolar vertebrate communities in the earliest Mesozoic.
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 P & eacute;rez 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.
Coastal erosion is a dynamic process driven by multiple environmental factors. In Antarctic regions, the interaction between wind, waves, sea ice, sediment transport and precipitation creates a complex setting for understanding shoreline change. This study focuses on Potter Cove, a small fjord in Maxwell Bay, south-west of King George Island (South Shetland Islands), where winter waves are investigated as a key erosive driver. Shoreline changes were assessed through satellite imagery, in situ beach profiling and sediment sampling. Additionally, a numerical wave modelling system was implemented to simulate wave dynamics within the cove. The results indicate a coastal retreat of up to 20 m along the southern shore of Potter Cove since 2020. Simulations for winter 2021 reveal two high-energy wave events with significant wave heights (Hs) of similar to 2 m, along with eight moderate events (Hs approximate to 1 m) occurring within the cove. The most energetic events (Hs = 2.11 m) originated offshore and entered directly through the cove's mouth from the west-south-west. Conversely, moderate waves could be generated both internally and externally. Reduced sea-ice cover probably diminished the natural wave-buffering effect, enhancing the erosive impact of wave action on the coast. However, the absence of quantitative assessments of other relevant processes (e.g. permafrost thaw, glacial meltwater discharge, sea-level variability and sediment supply) limits our ability to gain a comprehensive understanding of the ongoing erosion. These findings highlight the role of wave dynamics in Antarctic coastal change and the need for integrated monitoring approaches.
Concordia Station is a long-term lidar observatory in Antarctica. Its main purpose is to detect and classify polar stratospheric clouds (PSCs). In September 2023, water ice PSCs were observed for a period of 6 days. This has never occurred during the month of September in the 10 years of observations of PSCs at Concordia Station. In addition, the space-borne CALIOP (Cloud Aerosol Lidar with Orthogonal Polarization) lidar observed a rare occurrence of ice PSCs over Concordia Station during the first half of June. It is well known that the January 2022 eruption of the Hunga submarine volcano (20 degrees 32'S, 175 degrees 23'W) injected vast amounts of water vapour into the stratosphere. The Hunga hydration flooded southern high latitudes at the end of the 2022 austral winter, and the moist air was then entrained into the developing vortex in the austral autumn (April-May) of 2023. The increased water vapour from Hunga was reported to promote PSC formation by cooling the stratosphere and raising PSC formation temperatures. Here, we explore the impact of the Hunga eruption on the PSCs observed at Concordia Station.
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.
In recent decades, the extent of ice-free areas has been increasing in the South Shetland Islands (Maritime Antarctica). The coastal sector is one of the zones most significantly affected by glacial retreat, with newly exposed land surfaces undergoing a wide variety of post-glacial environmental processes. Coastal areas are characterized by both continental and marine ice dynamics, which in turn have major influences on the morphology and processes shaping coastal landforms. A detailed geomorphological analysis was carried out at Spanish Cove, south-west Livingston Island, which constitutes a boulder beach close to the Spanish Antarctic Station Juan Carlos I. This research provides a classification of the existing coastal landforms in this sector, as well as an analysis of the recent behaviour of the area using drone surveys, material size measurements obtained through semi-automatic techniques and hardness analysis using a durometer. This study represents one of the first attempts to classify the Antarctic coastal environment and offers a basis for understanding the potential evolution of such environments over the coming decades under global change and the rapid transformation of present-day glaciated landscapes.
Deception Island is an active, caldera-forming volcano whose surveillance is critically constrained by its extreme Antarctic isolation, scarce resources and limited seasonal human access. This study addresses these challenges by presenting an innovative Global Navigation Satellite Systems (GNSS) geodetic surveillance framework specifically adapted for such a remote environment. Our approach establishes a key operational distinction between non-real-time monitoring and near-real-time surveillance via a semi-continuous wireless network. We effectively resolve the inherent trade-off between promptness and precision by applying signal enhancement methods (e.g. Kalman filtering) to maintain millimetric accuracy in deformation detection, even when utilizing the high sampling rates (1 Hz) essential for rapid assessment. The resulting model allows for the rigorous isolation of the local volcanic signal from the complex regional tectonic kinematics. Crucially, data analysis reveals recurrent 3 year cycles of inflation and deflation in the magmatic system, strongly correlated with seismicity, which validates ground deformation as a reliable volcanic precursor. The primary practical advance is the validation of a dual-term hazard forecasting system: 1) mid-term (months) forecasts based on long-term time-series analysis to facilitate safe inter-campaign operations and 2) short-term (days) forecasting during periods of unrest using ground displacement acceleration, complemented by a magma injection model to predict the spatial location of potential vent openings. This validated and technologically adjusted framework provides an optimized and transferable template for continuous geodetic surveillance in other isolated, active polar volcanoes.
