In 2001 the LIMNOPOLAR Project was launched with the aim of addressing the suitability of freshwater ecosystems as useful sentinels of climate change. In this project, an automatic weather station was deployed on Byers Peninsula (Livingston Island, South Shetland Islands) near several freshwater ecosystems under research. Here the multi-year data recorded are presented and compared with meteorological time series from the observatories at the Spanish Juan Carlos I Station, Deception Island and Bellingshausen Station. Lake freezing and thawing periods and snow cover are also investigated. The main results indicate that Byers Peninsula is affected by the very cloudy and wet Antarctic maritime climate. Mean annual temperature is -2.8°C and summer mean temperatures are above freezing. The region shows moderate winds over the year and with moderate, mostly liquid precipitation during the summer. There is a significant linear relationship with meteorological records obtained from Juan Carlos I Station located on the east of Livingston Island. Correlations between meteorological data from both sites are high but with colder and much windier conditions on Byers Peninsula. Therefore, the usefulness and accuracy of meteorological records in the interpretation of ecosystem dynamics are presented.

Nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) fluxes were investigated from the algal-rich littoral zone of Lake Daming, East Antarctica during the summers of 2008/09 and 2009/10, using a static chamber technique. High N2O emissions occurred in the littoral zone with the mean flux range of 0.19–7.11 μmol N2O m-2 h-1. The mean CH4 fluxes ranged from 2.51–5.32 μmol CH4 m-2 h-1, and they were significantly affected by the lake thermal regime. There were significant differences (P < 0.05) in CH4 and N2O fluxes under the light and dark conditions, and sunlight greatly increased N2O emissions by stimulating the algal photosynthesis, but decreased CH4 emissions. Overall the littoral zone represented a weak CO2 sink with the mean flux range of -0.37–0.13 mmol CO2 m-2 h-1. The mean ecosystem respiration and photosynthesis rates varied from 0.47–2.90 mmol CO2 m-2 h-1 and from -0.33 to -2.63 mmol CO2 m-2 h-1. The combined global warming potential (GWP) of N2O and CH4 fluxes completely counteracted and surpassed CO2 uptake by the algal photosynthesis, and high GWP-positive of N2O and CH4 emissions might convert an algal-rich lake site with a net CO2 uptake into a net radiative forcing source during the ice-free period.

The Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project will test the overarching hypothesis that an active hydrological system exists beneath a West Antarctic ice stream that exerts a major control on ice dynamics, and the metabolic and phylogenetic diversity of the microbial community in subglacial water and sediment. WISSARD will explore Subglacial Lake Whillans (SLW, unofficial name) and its outflow toward the grounding line where it is thought to enter the Ross Ice Shelf seawater cavity. Introducing microbial contamination to the subglacial environment during drilling operations could compromise environmental stewardship and the science objectives of the project, consequently we developed a set of tools and procedures to directly address these issues. WISSARD hot water drilling efforts will include a custom water treatment system designed to remove micron and sub-micron sized particles (biotic and abiotic), irradiate the drilling water with germicidal ultraviolet (UV) radiation, and pasteurize the water to reduce the viability of persisting microbial contamination. Our clean access protocols also include methods to reduce microbial contamination on the surfaces of cables/hoses and down-borehole equipment using germicidal UV exposure and chemical disinfection. This paper presents experimental data showing that our protocols will meet expectations established by international agreement between participating Antarctic nations.

Age, growth and feeding habits of early life stages of Chionodraco rastrospinosus Dewitt & Hureau, the most abundant channichthyid in the larval fish assemblages of the Bransfield Strait, were studied by otolith microincrement counts and stomach content analyses. Individuals measuring 39–69 mm standard length were caught in the uppermost depth strata down to 300 m from Brabant to Joinville islands along the northern Antarctic Peninsula. The sample consisted of post-larvae and juveniles aged 105–211 days, with a mean growth rate of 0.25 mm day-1. Larval size at hatching was estimated to be c. 17.2 mm. Hatching was spread over a relatively long period from August–November. Sagittal otoliths were characterized by a strong check located at 23–52 microincrements of distance from the core, tentatively associated with the onset of first exogenous feeding. The relatively long period during which larvae can rely on yolk reserves and the large size at hatching enable them to utilize a wide size range of prey, as well as cope with occasional food shortages. The stomach contents consisted exclusively of euphausiids (furcilia and adults) and larvae of Pleuragramma antarcticum Boulenger. Based on growth rate, the residence time in pelagic waters of juvenile C. rastrospinosus was estimated to be about a year and a half.

Introduced house mice Mus musculus L. have been discovered to be major predators of chicks of the Tristan albatross Diomedea dabbenena L. and Atlantic petrel Pterodroma incerta Schlegel and to also predate great shearwater Puffinus gravis O'Reilly chicks at Gough Island, and similar predatory behaviour has been reported for house mice on Marion Island. Observations on Gough Island over three breeding seasons of nesting Atlantic yellow-nosed albatrosses Thalassarche chlororhynchos Gmelin and dark-mantled sooty albatross Phoebetria fusca Hilsenberg indicate that house mice are also preying on these two species: the first records of mice preying upon summer-breeding albatross species on Gough Island. Predation on these two albatross species appears to be relatively rare (∼2% for the Atlantic yellow-nosed albatrosses) and ongoing monitoring is required to ascertain if the impact of mice is increasing. Conservation actions to eradicate mice from Gough Island will be of benefit to these species and other species that are being impacted by this invasive species.

A small, inconspicuous lichen, Acarospora cf. badiofusca, was discovered colonizing iron-stained quartz mica schists on the lower slope of Manhaul Rock, a recently exposed nunatak on the McLeod Glacier, Signy Island, South Orkney Islands. Thallus colour ranged from rust on exposed rock surfaces to paler orange and green in shaded crevices. This study addressed the hypothesis that colour reflects element localization, and considered substance localization within lichen tissues and responses to stress. Electron microprobe analysis of specimens confirmed that Fe is localized principally in the outer rust-coloured part of the cortex, confirming that the colour reflects Fe localization. Oxalates, widely reported as contributing to tolerance mechanisms to environmental stress, were not detected using X-ray diffraction. The upper thallus surface consisted of sub-micron particulate phases containing Fe, Al and O, suggesting mixed oxide/hydroxide phases are present and play a role in photoprotection.

Few parts of Antarctica are not permanently covered in ice. The retreat of the ice sheet from Byers Peninsula on western Livingston Island, Maritime Antarctica, has provided a new area of seasonal snow cover. Snow surveys were conducted in late November 2008 at the time of peak accumulation across the 1 km2 Lake Limnopolar watershed. Topographic variables were derived from a digital elevation model to determine the variables controlling the presence or absence of snow and the distribution of snow depth. Classification with binary regression trees showed that wind related variables dominated the presence and depth of snow. The product of the sine of aspect and the sine of slope was the first variable in both regression trees. Density profiles were also measured and illustrated a relatively homogeneous snowpack over space at peak snow accumulation.

Scullin and Murray monoliths are thought to hold the largest concentration of breeding seabirds in East Antarctica. The monoliths were designated as an Antarctic Specially Protected Area (ASPA No. 164) in 2005 in recognition of the global importance of the seabird assemblages and to protect their outstanding ecological and scientific values. The management plan for the Scullin and Murray Monoliths ASPA encourages regular seabird population monitoring using methods such as aerial photography, but the complex logistics of accessing this remote site has until now limited quantitative assessment of the seabird populations to a single survey in 1986/87. In December 2010 we photographed the Adélie penguin population to provide the population counts presented here. We discuss the potential biases and uncertainties in estimating the breeding population from both the recent and 1980s population count data.

In Antarctica, mass accumulations of psychrophilic algae cause striking phenomena like green, orange, or red snow. This occurs during summer, when coastal snowfields start to melt, become waterlogged and photoautotrophs can thrive. Chloromonas polyptera (Fritsch) Hoham, Mullet & Roemer is a unicellular species that causes orange snow in the vicinity of penguin rockeries. It has been recognized for many decades because of the distinct habitat and the characteristic morphology of cysts with elongated flanges on the outer cell wall. However, closer investigations concerning the ecology or physiology have been sparse so far. Field material was collected from two sites on the Antarctic Peninsula to find out more about metabolic and cellular strategies. The results were compared with a closely related species from high alpine locations, Chloromonas nivalis (Chodat) Hoham & Mullet. Despite the geographical distance, C. polyptera shares several physiological strategies with the alpine relative, such as the formation of cyst stages, saccharose and glycerol as main soluble carbohydrates and the abundant accumulation of the carotenoid astaxanthin. Moreover, photosynthesis is adapted to temperatures of about 1°C. The molecular phylogeny confirmed a close relationship of C. polyptera to other Chloromonas species isolated from snow. Chloromonas polyptera seems to be exclusive to coastal Antarctic ecosystems influenced by animal nutrient input.

Knowledge of spatial distribution is fundamental to ecological studies and crucial for conservation and management of species and biodiversity, but detailed, large-scale spatial data are lacking for most taxa. Although the Adélie penguin is one of the most intensively studied Antarctic vertebrates, spatial data that could aid in ecological study and conservation management are incomplete. We undertook a large-scale survey of the current breeding distribution of Adélie penguins along 3800 km of the East Antarctic coastline. The survey increased the number of known breeding locations by 50% and revealed that the breeding distribution has expanded in some parts of the survey region over the past two to three decades. The expanding breeding distribution may reflect underlying population dynamics of sustained growth and resultant density dependent effect on dispersal and movement from established breeding sites to new sites. The comprehensive, large-scale distribution data from this study will form a baseline for assessing any future changes in Adélie penguin breeding distribution, provide data for developing spatial models for predicting future changes in breeding distribution under plausible scenarios of environmental change, and contribute to the development of metapopulation models by providing estimates of local colonization and extinction probabilities under specific conditions of metapopulation change.

Analysis of conglomerates and sandstones of the Sperm Bluff Formation at the base of the Taylor Group (Devonian) between the Mackay Glacier and Bull Pass provides new insights into the nature of initial coarse-grained deposition on basement along the northern side of the McMurdo sedimentary basin. Six lithofacies are recognized in the Sperm Bluff Formation: conglomerate lithofacies, pebbly sandstone lithofacies, cross-bedded sandstone lithofacies, low-angle cross-stratified sandstone lithofacies, bioturbated sandstone lithofacies and interbedded siltstone/sandstone lithofacies. Sedimentary environments ranged from wave-dominated delta, estuary or lagoon to shoreface and inner shelf. The assemblage is thought to reflect changes in sea level. Rhyolite is the most abundant clast type in the coarse lithofacies, but is unknown in outcrop in southern Victoria Land. The rhyolites correlate in age and geochemistry with Cambrian granites in the basement. Coarse beds also contain numerous quartzite clasts, probably derived from the late Precambrian Skelton Group. Palaeocurrents on Mount Suess indicate a strong unimodal flow to the west, but other sites show polymodal palaeoflow. The Sperm Bluff Formation is correlated with Terra Cotta Siltstone, New Mountain Sandstone and Altar Mountain formations based on the lithology of sandstones and their ichnology. A northward onlap during the Early Devonian is indicated.

An interception trap to collect airborne arthropods under extreme weather conditions is described. The trap, constructed from durable materials, is operated by wind pressure. It consists of a funnel of fine brass gauze mounted inside a cylinder of stainless steel that rotates into the wind on a mast at 1.5 m from the ground. The gauze funnel terminates in a removable, propanol-filled, collecting bottle into which airborne material accumulates. The counterbalanced cylinder rotates around a central shaft on roller bearings and faces into the wind. Two traps were successfully operated continuously for four and five years, respectively, on sub-Antarctic Macquarie Island and have collected large numbers of airborne arthropods and other biological material over this period.

The juvenile phase is poorly known in Antarctic seabirds, despite being a critical period for individual survival. To better understand the ecology of young Antarctic seabirds, we surveyed for the first time the three-dimensional habitat use of six juvenile emperor penguins during their post-natal dispersal from Terre Adélie, using bio-telemetric tags. The tags transmitted location and activity data for nearly 100 days on average. One individual was followed during eight months and covered 7000 km, which represents the longest continuous individual survey for the species. Studied individuals first dispersed away from Antarctica, up to 54.7°S and 1250 km north of the pack-ice edge, in the Polar Frontal Zone. This highlighted a much looser association with sea ice and a greater at-sea range compared to previous knowledge on breeding adults. Juvenile penguins then moved southwards close to the extending pack-ice during autumn and winter. Over the survey duration, juveniles showed a contrasting use of marine habitats, with less mobility, less time underwater, and shallower dives (generally not over 50–100 m) in the pack ice, versus greater distances travelled, more time spent underwater, especially deeper than 100 m (up to 250–300 m) in open water. We discuss hypotheses which could explain the northward exodus of juvenile emperor penguins across contrasting habitats.

In order to monitor the evolution of the active layer in the South Shetland Islands, in February 2009 we established a new Circumpolar Active Layer Monitoring (CALM) site in the Limnopolar Lake basin on Byers Peninsula, Livingston Island. We monitored air, surface and ground (two boreholes of 135 and 80 cm deep) temperatures and Active Layer Thickness (ALT) was measured by mechanical probing in early February 2009, 2010 and 2011. The mean ALT was 44 cm with a range of about 92 cm, but where permafrost existed it was deeper than 1.0 m, as could be inferred from the borehole temperatures. ALT at this site was very dependent on air temperature and snow cover thickness, the ALT spatial distribution presenting the same pattern as soil penetration resistance, and higher values ALT coinciding with sites where patterned ground, ponds, and a near surface ground water saturation were observed. Additionally, ground temperature data provided an excellent tool for understanding the relationship between the ALT measured during the thaw season and the thermal evolution of the ground throughout the year.

We reviewed photographic images of fishes from depths of 381–2282 m in Marguerite Bay and 405–2007 m in the Amundsen Sea. Marguerite Bay fishes were 33% notothenioids and 67% non-notothenioids. Channichthyids (47%) and nototheniids (44%) were the most abundant notothenioids. The deep-living channichthyid Chionobathyscus dewitti (74%) and the nototheniid genus Trematomus (66%) were the most abundant taxa within these two families. The most abundant non-notothenioids were the macrourid Macrourus whitsoni (72%) and zoarcids (18%). Amundsen Sea fishes were 87% notothenioids and 13% non-notothenioids, the latter exclusively Macrourus whitsoni. Bathydraconids (38%) and artedidraconids (30%) were the most abundant notothenioids. We observed that Macrourus whitsoni was benthopelagic and benthic and infested by large ectoparasitic copepods. Juvenile (42 cm) Dissostichus mawsoni was not neutrally buoyant and resided on the substrate at 1277 m. Lepidonotothen squamifrons was seen near and on nests of eggs in early December. A Pogonophryne sp. from 2127 m was not a member of the deep-living unspotted P. albipinna group. Chionobathyscus dewitti inhabited the water column as well as the substrate. The pelagic zoarcid Melanostigma gelatinosum was documented in the water column a few metres above the substrate. The zoogeographic character of the Marguerite Bay fauna was West Antarctic or low-Antarctic and the Amundsen Sea was East Antarctic or high-Antarctic.

We utilized an automated ribosomal intergenic spacer analysis (ARISA) method as a more rapid alternative to classical morphological/nutritional identification and a less expensive alternative to sequencing for identification and grouping of isolates in culture-based fungal abundance studies. This method is well suited for the study of culturable Antarctic soil fungal communities where both abundance and diversity are relatively low. We optimized template concentration and verified the effect of primer selection from eight commonly used fungal polymerase chain reaction primers on ARISA chromatographs for 46 fungal species commonly isolated from south Victoria Land. A database of Antarctic fungal electropherograms was produced containing each of the species and was used as the first step in a tiered system for species identification. In addition, isolates containing more than one species were identified, allowing isolates not in the database to be sequenced for further analysis. This method unambiguously identified 78% of the fungal taxa in this study and we were able to rapidly determine which isolates should be subjected to further analysis by DNA sequencing. Using this approach, the cost of analysis for abundance studies can be greatly reduced compared to DNA sequencing of each isolate.

Despite small direct anthropic/anthropogenic influence, Antarctica cannot be considered out of the reach of pollutants. The present study evaluated the distribution and transfer of the following organic pollutants: PCBs (polychlorinated biphenyls), organochlorine pesticides and PBDEs (polybrominated diphenyl ethers) in invertebrates, fish, bird eggs and liver samples from Admiralty Bay, King George Island, South Shetland Islands. The prevailing compounds were (in ng g-1 wet weight for species averages): PCBs up to 1821 for birds, 6.82 for fish and 41.3 for invertebrates, HCB (hexachlorobenzene) up to 69.8 for birds, 0.66 for fish and 0.56 for invertebrates and DDTs (dichlorodiphenyltrichloroethane) up to 524 for birds, 3.04 for fish and 0.74 for invertebrates. PBDEs (detected only in bird eggs and liver, up to 39.1 and 7.95, respectively) occurred in levels one or two orders of magnitude lower than organochlorines, probably due to the lower and more recent usage of PBDEs. The qualitative profiles of PCBs agree with trophic level and diet data. PBDEs showed small difference in composition when compared to the technical product available in the Americas, especially in endemic species, which could indicate that fractionation does not have a major role for this contaminant group. Trophic level, but also and more importantly, diet, range, ecological niche and “growth dilution” effect explain the variation of pollutants concentrations found in this study.

In January and February 2009, a series of water samples were collected from streams on Byers Peninsula. These samples were analysed for major elements and δ18O to determine the role of lithology and landscape position on stream geochemistry, and to understand better the hydrology (i.e. residence time of water) of these systems. Precipitation chemistry is enriched in Na+, as are the streams located close to the coast. Streams originating from inland locations have much higher percentages of Ca2+. In contrast, Mg2+ varied little, though streams that are in greater contact with volcanic-derived soils have slightly higher concentrations. Anion percentages varied greatly between streams with SO42- ranging from 5% to 45% of the anion composition. Dissolved Si concentrations as high as 141 μM were observed. All these data suggest that active chemical weathering is occurring in this region. A time series over 13 days at one stream showed little variation in major element geochemistry. The δ18O of precipitation samples collected over this same period varied by ∼10‰ while the majority of stream samples varied less than ∼1.5‰. These data indicate that the stream waters represent mixtures of precipitation events, melting snow and water from the subsurface that had gained solutes through chemical weathering.

Pony Lake, at Cape Royds, Antarctica, is a shallow, eutrophic, coastal lake that freezes solid in the winter. Changes in Pony Lake's physicochemical parameters and microbial community were studied during the transition from ice to open water. Due to rising water temperatures, the progressive melt of the ice column and the gradual mixing of basal brines into the remaining water column, Pony Lake evolved physically and chemically over the course of the summer, thereby affecting the microbial community composition. Temperature, pH, conductivity, nutrients and major ion concentrations reached their maximum in January. Pony Lake was colonized by bacteria, viruses, phytoflagellates, ciliates, and a small number of rotifers. Primary and bacterial production were highest in mid-December (2.66 mg C l-1 d-1 and 30.5 μg C l-1 d-1, respectively). A 16S rRNA gene analysis of the bacterioplankton revealed 34 unique sequences dominated by members of the β- and γ-proteobacteria lineages. Cluster analyses on denaturing gradient gel electrophoresis (DGGE) banding patterns and community structure indicated a shift in the dominant members of the microbial community during the transition from winter ice, to early, and late summer lakewater. Our data demonstrate that temporal changes in physicochemical parameters during the summer months determine community dynamics and mediate changes in microbial species composition.