Two automatic snow stations were deployed for one year (from December 2009–January 2011) in western Dronning Maud Land. The purposes of the experiment were: 1) to build a working snow station to measure the snow surface layer temperature, and 2) to use the data for snow heat and mass balance investigations. The data collection was successful and lasted about 400 days (9 December 2009–21 January 2011). The annual net snow accumulation at snow station 2 (continental ice sheet) was 86 cm (345 mm water equivalent) and at snow station 1 (ice shelf) more than 150 cm. The power spectra revealed daily cycle, synoptic scale variability, and variability in a low-frequency band of 60–120 days at a depth of 54 cm. The snow-air heat flux was estimated from the data, resulting in negative values (from snow to air) during autumn and winter and positive values (from air to snow) in spring and summer. The physical characterization of snow stratigraphy was done during installation and retrieval of the snow stations, including density, hardness (hand test), stratigraphy, and grain size and shape.

New determinations of ocean tides are extracted from high-rate Global Positioning System (GPS) solutions at nine stations sitting on the Ross Ice Shelf. Five are multi-year time series. Three older time series are only 2–3 weeks long. These are not ideal, but they are still useful because they provide the only in situ tide observations in that sector of the ice shelf. The long tide-gauge observations from Scott Base and Cape Roberts are also reanalysed. They allow determination of some previously neglected tidal phenomena in this region, such as third-degree tides, and they provide context for analysis of the shorter datasets. The semidiurnal tides are small at all sites, yet M2 undergoes a clear seasonal cycle, which was first noted by Sir George Darwin while studying measurements from the Discovery expedition. Darwin saw a much larger modulation than we observe, and we consider possible explanations - instrumental or climatic - for this difference.

Fildes Peninsula, on King George Island, has been greatly influenced by recent rapid climate warming. Lakes are pervasive features of Fildes Peninsula landscapes, some of which are used as water sources for Antarctic stations. We studied seven Fildes Peninsula lakes to explore differences among lakes and between seasons in phytoplankton and bacterioplankton communities. We measured environmental variables, analysed pigments using high-performance liquid chromatography and examined bacterial DNA through high-throughput sequencing of the 16S rRNA gene. The main driver structuring microbial communities was the season (i.e. spring vs autumn). Chlorophyceae were the dominant phytoplankton group in all lakes and both seasons. Indicator bacteria for each season were identified, including Flavobacterium, Polaromonas and Oxalobacteraceae as indicators of spring conditions under thick ice, whereas Frankiales and Verrucomicrobia were indicator species of autumn following the ice-free summer. The indicator species for spring are generally observed in oligotrophic conditions, whereas many of the autumn indicators are commonly found in soils. There were lesser between-lake differences in microbial communities in autumn, at the end of the open-water period, than in spring at the end of the ice-covered period. This study will act as the basis for future assessments of changes in aquatic microbial communities.

We used a multidisciplinary approach integrating major, trace and rare earth element geochemistry, mineralogy of rocks and sediments along with the ionic composition of water reservoirs of Admiralty Bay, King George Island, to evaluate the record of water-rock interactions under Maritime Antarctic conditions. Our results showed that the ionic compositions of the streams and meltwaters predominantly reflect the atmospheric inputs, while lake waters have higher Na/Cl, Ca/Mg and HCO3/Cl ratios related to chemical weathering in lake sediments, but this did not allow for distinguishing purely silicate sources. Consistent with the trace and rare earth element data, various alteration indices and Index of Compositional Variability values denote the low degree of chemical weathering in the lake sediments. The records from the previously unexplored Mud Lake and Upper Lake suggest that the lakes of Admiralty Bay are better places to trace the impacts of a succession of environmental changes that have occurred in the watershed, while the stream channel sediments, when accompanied by water chemistry data, may provide a more representative composition of the source rocks than the lake sediments. These findings may help revealing the intensity of contemporary weathering in a colder climate with relatively few mineralogical changes accompanied by a lesser degree of elemental loss.

Wright Valley, Victoria Land contains numerous aquatic habitats suitable for the growth of algae in summer. Excepting diatoms and lichen phycobionts, algal diversity and distribution in the valley was documented. Using cultures and environmental cloning eight cyanobacterial and 14 eukaryotic species were revealed. The cyanobacterium Microcoleus vaginatus and the chlorophycean Chlorococcum sp. 1 were the most common, both occurring in more than one habitat (ponds, soils or streams). Ponds harboured the most diverse communities. Habitat specialization was rare. Chlamydomonads were not found outside ponds, but species capable of zoospore production were able to colonize ponds and soils. Nostocalean cyanobacteria were not detected. Results suggest dispersal within and between valleys, with little evidence of Antarctic endemism. All but one cyanobacterium with similar internally transcribed spacer (ITS) length to clones from Miers Valley proved to be different species when 16S rRNA gene sequences were also considered; thus, ITS length is unreliable for assessing identity and biogeography of these cyanobacteria. Comparison with a 454 16S rRNA gene soil dataset from Wright Valley indicated the occurrence of only one of the cyanobacterial species, the distribution of which may be limited by salinity.

Limited sampling has so far been conducted of the meroplankton community of the high Antarctic, with most research being conducted using vertical hauls in waters > 50 m, and little focused research on the meroplankton community directly under the sea ice (cryopelagic). Here we report the composition of the early summer cryopelagic meroplankton community of the shallow waters of Gerlache Inlet, Terra Nova Bay. A fixed-frame stationary plankton net was deployed c. 1 m below the annual sea ice and sampled at c. 24 hour intervals over a period of 19 days from mid-November to early December 2006. A total of 173 larvae from the phyla Annelida (n = 66), Mollusca (n = 30), Nemertea (n = 4), Echinodermata (n = 8), several Pleuragramma antarcticum (n = 4) and numerous planulae (n = 61) were collected, as well as 265 egg/embryo stages. A mean of 9.1 larvae (SD = 7.3, n = 19) and 13.9 eggs/embryos (SD = 20.5, n = 19) were found directly below the sea ice in each 24 hour period, and these early life history stages may be subject to the hazards of extensive platelet ice and penetrating ultraviolet radiation. The cryopelagic meroplankton community of shallow water is also compositionally similar to that of deeper waters, suggesting that the 50–0 m plankton tows used in previous research are providing a reliable assessment of the biodiversity of coastal Antarctic meroplankton.

Researchers have previously assumed that common diving petrels (Pelecanoides urinatrix) have a limited sense of smell since they have relatively small olfactory bulbs. A recent study, however, showed that adult diving petrels prefer the scent of their own burrow compared to burrows of other diving petrels, implying that personal scents contribute to the burrow's odour signature. Because diving petrels appear to be adapted to use olfaction in social contexts, they could be a useful model for investigating how chemically mediated social recognition develops in birds. A first step is to determine whether diving petrel chicks can detect familiar and unfamiliar odours. We compared behavioural responses of chicks to three natural stimuli in a wind tunnel: soil collected from their burrow or colony, and a blank control. During portions of the experiment, chicks turned the least and walked the shortest distances in response to odours from the nest, which is consistent with their sedentary behaviour within the burrow. By contrast, behaviours linked to olfactory search increased when chicks were exposed to blank controls. These results suggest that common diving petrel chicks can detect natural olfactory stimuli before fledging, and lay the foundation for future studies on the role of olfaction in social contexts for this species.

Recent meteorological studies suggest a mixed pattern of climate change in Antarctica: a general cooling of the interior continent and warming in the Antarctic Peninsula over the past several decades (e.g. Comiso 2000, Doran et al. 2002, Vaughan et al. 2003). This note presents 10 years of continuous recording of air and permafrost temperature at Mount Melbourne (74°21′S, 164°42′E) in Northern Victoria Land. Mount Melbourne is a quiescent volcano belonging to a wide-spread volcanic belt which has developed since the Oligocene along the western margin of the Ross Sea, parallel to the Transantarctic Mountains (Fig. 1a). In 1988 a tilt network composed of five continuous recording sensors each equipped with four temperature sensors (Fig. 1b) was installed within the framework of Italian PRNA between the end of 1988 and the beginning of 1989 (Bonaccorso et al. 1995).

We conclude that the extinct polar forests of Antarctica deserve recognition as a distinct biome - the ‘Austral Polar Forest Biome’ - rather than being regarded as analogous to modern rainforest.

The flightless midge Eretmoptera murphyi is thought to be continuing its invasion of Signy Island via the treads of personnel boots. Current boot-wash biosecurity protocols in the Antarctic region rely on microbial biocides, primarily Virkon® S. As pesticides have limited approval for use in the Antarctic Treaty area, we investigated the efficacy of Virkon® S in controlling the spread of E. murphyi using boot-wash simulations and maximum threshold exposures. We found that E. murphyi tolerates over 8 h of submergence in 1% Virkon® S. Higher concentrations increased effectiveness, but larvae still exhibited > 50% survival after 5 h in 10% Virkon® S. Salt and hot water treatments (without Virkon® S) were explored as possible alternatives. Salt water proved ineffective, with mortality only in first-instar larvae across multi-day exposures. Larvae experienced 100% mortality when exposed for 10 s to 50°C water, but they showed complete survival at 45°C. Given that current boot-wash protocols alone are an ineffective control of this invasive insect, we advocate hot water (> 50°C) to remove soil, followed by Virkon® S as a microbial biocide on ‘clean’ boots. Implications for the spread of invasive invertebrates as a result of increased human activity in the Antarctic region are discussed.

Human- and animal-impacted sites in Antarctica can be contaminated with heavy metals, as well as areas influenced by underlying geology and naturally occurring minerals. The present study examined the relationship between heavy metal presence and soil microalgal occurrence across a range of human-impacted and undisturbed locations on Signy Island. Microalgae were identified based on cultures that developed after inoculation into an enriched medium. Twenty-nine microalgae representing Cyanobacteria, Bacillariophyta, Chlorophyta and Tribophyta were identified. High levels of As, Ca, Cd, Cu and Zn were detected in Gourlay Peninsula and North Point, both locations hosting dense penguin rookeries. Samples from Berntsen Point, the location of most intense human activity both today and historically, contained high levels of Pb. The contamination factor and pollution load index confirmed that the former locations were polluted by Cd, Cu and Zn, with these being of marine biogenic origin. Variation in the microalgal community was significantly correlated with concentrations of Mn, Ca, Mg, Fe, Zn, Cd, Co, Cr and Cu. However, the overall proportion of the total variation contributed by all metals was low (16.11%). Other factors not measured in this study are likely to underlie the majority of the observed variation in microalgal community composition between sampling locations.

The macroalgae of the Balleny Islands (66°15′S–67°35′S and 162°30′E–165°00′E) have been infrequently collected and the flora remains poorly known. This chain of islands is located on the edge of the Antarctic Circle in the northern Ross Sea, ~250 km north of the coast of northern Victoria Land, and it represents the most northerly land in the Ross Sea region. As well as being very remote, access to these islands is difficult given the highly variable prevailing ice conditions. We summarize the macroalgal floras of the Balleny Islands and the Ross Sea, including reporting new records, extending the known distribution of other taxa and highlighting the need for further taxonomic research on some of the most common and widespread species. Many of the taxa reported have been collected on few occasions and, as a consequence, there is insufficient material available, including reproductively mature samples, for some species to be fully documented. While these collections are providing intriguing insights into the relationships between the macroalgae found around the Antarctic continent, the full biodiversity of the Balleny Islands remains to be investigated, and further collections are required to enable detailed comparisons with other parts of the Antarctic region.

The South Fork of Wright Valley contains one of the largest rock glaciers in the McMurdo Dry Valleys, Antarctica, stretching 7 km from the eastern boundary of the Labyrinth and terminating at Don Juan Pond (DJP). Here, we use results from ground-penetrating radar (GPR), qualitative field observations, soil leaching analyses and X-ray diffraction analyses to investigate rock glacier development. The absence of significant clean ice in GPR data, paired with observations of talus and interstitial ice influx from the valley walls, support rock glacier formation via talus accumulation. A quartz-dominated subsurface composition and discontinuous, well-developed desert pavements suggest initial rock glacier formation occurred before the late Quaternary. Major ion data from soil leaching analyses show higher salt concentrations in the rock glacier and talus samples that are close to hypersaline DJP. These observations suggest that DJP acts as a local salt source to the rock glacier, as well as the surrounding talus slopes that host water track systems that deliver solutes back into the lake, suggesting a local feedback system. Finally, the lack of lacustrine sedimentation on the rock glacier is inconsistent with the advance of a glacially dammed lake into South Fork during the Last Glacial Maximum.

We describe a major shear zone exposed at Akebono Rock and discuss its deformation and metamorphic history, with a view to providing a better understanding of the geological history of the Lützow-Holm Complex. Three deformation episodes are recognized: D1 produced open folds (F1), boudinage and a regional ductile foliation, whilst the related metamorphic facies is characterized by stable garnet. F1 folding is dominantly preserved in the eastern part of the study area. During D2, an isoclinal to tight asymmetric F2 folds developed mainly in the west part of the region, accompanied by an S2 shear, under biotite facies retrograde metamorphism. The D3 episode involved the formation of the major shear zone, characterized by mylonite and L-tectonite fabrics, which took place at ~610–660°C and 4–5 kbar. Large, sigmoidal garnet core domains have S-shaped inclusion trails, suggesting that syntectonic garnet growth occurred before the formation of the shear zone. Estimated P-T conditions suggest that the sigmoidal garnet-bearing amphibolite was recrystallized at a deeper crustal level and was brought to a higher level during the formation of the shear zone. Crustal-scale deformation involving syntectonic recrystallization and shearing of Akebono Rock is a key issue for reconsidering the evolution of the Lützow-Holm Complex.

Antarctic algae are extremophilic organisms capable of surviving harsh environmental conditions such as low temperatures and deep dehydration. Although these algae have various adaptations for life in extreme environments, the majority of the molecular mechanisms behind their resistance to dehydration and freezing are not yet fully understood. The aim of our research was to observe the behaviour of bound water freezing in the free-living Antarctic alga Prasiola crispa. One way to avoid frost damage involves deep dehydration of the algal thallus. For that reason, a detailed analysis of water freezing at different sample hydration levels was carried out. Nuclear magnetic resonance investigation revealed two types of water immobilization: cooperative bound water freezing for samples with sample hydration levels above Δm/m0 = 0.40 and non-cooperative bound water immobilization for lower thallus hydration levels. In the differential scanning calorimetry experiment, 2-h incubation at -20°C suggested the diffusion and final binding of supercooled water to the ice nuclei and a lower hydration level threshold, at which ice formation could be observed (Δm/m0 = 0.21). Our research provides a new perspective on water sorption and freezing in Antarctic algae, which may be important not only in biological systems, but also in such novel materials as metal-organic frameworks or covalent organic frameworks.

The Antarctic Peninsula is undergoing rapid change due to global warming, including air and water temperature increases. Fauna inhabiting the intertidal zone are particularly exposed to warming impacts, as they are subjected to high variations in both terrestrial and marine environmental settings. This study aimed to assess intertidal macrofaunal and meiofaunal biodiversity, tidal height-related assemblage structural patterns and their responses to variability in environmental parameters on King George Island. A total of 39 macrofaunal taxa were identified, with polychaetes and amphipods being the most diverse groups and gastropods, amphipods and bivalves being the most abundant. In the case of meiofauna, 16 taxa were found, mainly nematodes, copepod nauplii and harpacticoids. There was a significant decrease in the number of species, abundance and biomass for both macrofauna and meiofauna with increasing tidal height. Our investigation documented highly diverse and abundant fauna in the Antarctic intertidal zone. With its thriving life, it could serve as a perfect model system for detecting climate change impacts on local biodiversity. Therefore, we propose the Antarctic intertidal zone as a suitable habitat for monitoring these changes.

Carrion in the form of dead seal pups and algal mats placed on soft bottom habitats at Explorers Cove and Salmon Bay, McMurdo Sound, attract scavenging invertebrates that are driven away by hydrogen sulphide produced by sulphate-reducing bacteria sequestered below a layer of Beggiatoa/Thioploca-like filamentous bacteria. This system is usually found for lipid-rich marine mammal carrion, but also occurred with natural algal mats.