The aim of this study was to develop a methodology to assess the degree of multidisciplinarity and international co-operation between scientists working on Deception Island, using techniques based on social network analysis. A database was built of the scientific output, as represented by published articles, on Deception Island between 1964–2012. From the 173 published articles, the main topics, the temporal trends, the profile of the principal journals, and the contributions made by each country, research institution and scientist were obtained. The data presented show a significant role played by four of the six nations belonging to the Deception Island Management Group. However, collaborations between researchers in different fields was unusual and co-authoring by researchers from different countries was relatively low. These results show that there is a need to strengthen international co-operation, a highly advisable strategy in Antarctica due to the complexity of logistics and high operational costs. Studies such as this may help to identify synergies between institutions and researchers from different nations, improving the scientific collaboration in this area of priority for conservation and management.

Observer-based studies often underestimate key ecological parameters. Here a fresh approach was used to analyse six years (2006–11) of attendance cycles to estimate foraging trip lengths of a lactating flipper-tagged otariid: subantarctic fur seals at Marion Island. Multi-state mark-recapture models were used to calculate detection failures of females, correct estimates accordingly, and investigate the effects of year, season, pup sex and the presence of a telemetry device on attendance cycle parameters. There were no differences between corrected and uncorrected attendance data. This is attributed to the high capture probability across all seasons (range: 83–98%). This illustrates that observer-based studies are useful to augment telemetry studies. Only season and pup sex had a significant impact on female provisioning rates. In winter, foraging trip durations were longer (t-value=25.22, P<0.0001) and attendance durations shorter (t-value=-2.15, P=0.01) than during summer. Females with female pups spent a higher proportion of their time on land (χ2=6.6, P<0.05). Male pups have higher growth demands and are larger which suggests they can deplete female milk-stores faster.

The Scotia Arc and Amundsen Sea are contrasting regions within West Antarctica. The Scotia Sea shelf is well studied and central to the origin and diversity of the Southern Ocean benthic fauna, whilst the shelf of Amundsen Sea is one of the least studied shelf areas in the world; a ‘white spot’ on the map of benthic research. Here we report on the tanaidaceans collected using an epibenthic sledge on two expeditions, BIOPEARL 1 and 2, of the RRS James Clark Ross in 2006 and 2008, respectively. This study represents the first analysis of the tanaidacean fauna of those two basins. Thirty-seven species were found in the Amundsen Sea from 500–1500 m depth and 51 species were found at depths ranging from 200–1600 m in the Scotia Sea. In the Scotia Sea, many species were unique to each of the study sites which may be evidence of allopatric speciation episodes. Site specificity was especially evident for Typhlotanais and Pseudotanais. Only three species were common to both basins. Around 90% of the species were previously undescribed. Our findings increase the number of the tanaidaceans known in the Southern Ocean by 50%.

Since 2004 there has been mounting evidence of the severe impact of introduced house mice (Mus musculus L.) killing chicks of burrow-nesting petrels at Gough Island. We monitored seven species of burrow-nesting petrels in 2014 using a combination of infra-red video cameras augmented by burrowscope nest inspections. All seven camera-monitored Atlantic petrel (Pterodroma incerta Schlegel) chicks were killed by mice within hours of hatching (average 7.2±4.0 hours) with an 87% chick failure rate (n=83 hatchlings). Several grey petrel (Procellaria cinerea Gmelin) chicks were found with mouse wounds and 60% of chicks failed (n=35 hatchlings). Video surveillance revealed one (of seven nests filmed) fatal attack on a great shearwater (Puffinus gravis O’Reilly) chick and two (of nine) on soft-plumaged petrel (Pterodroma mollis Gould) chicks. Mice killed the chicks of the recently discovered summer-breeding MacGillivray’s prion (Pachyptila macgillivrayi Mathews), with a chick mortality rate of 82% in 2013/14 and 100% in 2014/15. The closely-related broad-billed prion (P. vittata Forster) breeds in late winter and also had a chick mortality rate of 100% in 2014. The results provide further evidence of the dire situation for seabirds nesting on Gough Island and the urgent need for mouse eradication.

Organochlorine contaminants (OCs) and polybrominated diphenyl ethers (PBDEs) were investigated in the eggs of five bird species from the South Shetland Islands. Additionally, OCs and PBDEs were also analysed in embryos of two species. The concentration ranges in eggs were (ng g-1 wet weight) 2.11 to 541 for polychlorinated biphenyls (PCBs), <0.25 to 0.88 for PBDEs, 2.45 to 405 for p,p’-DDE and 1.50 to 603 for mirex. The PCBs were predominant in the eggs of Macronectes giganteus, Catharacta antarctica and Larus dominicanus, whereas hexachlorobenzene (HCB) was the major compound found in the eggs of Pygoscelis antarcticus and Sterna vittata. The PBDE congeners were detected only in the eggs of C. antarctica (PBDE 47 and 153) and S. vittata (PBDE 47). There were differences in OC concentrations of up to two orders of magnitude between M. giganteus embryos which were related to the development stage and OC concentrations in the respective eggs. Trophic ecology and post-breeding dispersal exerted an influence on contaminant patterns. Comparisons with data from the literature indicate an increase in the concentrations of some OCs over recent years.

Wastewater containing human sewage is often discharged with little or no treatment into the Antarctic marine environment. Faecal sterols (primarily coprostanol) in sediments have been used for assessment of human sewage contamination in this environment, but in situ production and indigenous faunal inputs can confound such determinations. Using gas chromatography with mass spectral detection profiles of both C27 and C29 sterols, potential sources of faecal sterols were examined in nearshore marine sediments, encompassing sites proximal and distal to the wastewater outfall at Davis Station. Faeces from indigenous seals and penguins were also examined. Faeces from several indigenous species contained significant quantities of coprostanol but not 24-ethylcoprostanol, which is present in human faeces. In situ coprostanol and 24-ethylcoprostanol production was identified by co-production of their respective epi-isomers at sites remote from the wastewater source and in high total organic matter sediments. A C29 sterols-based polyphasic likelihood assessment matrix for human sewage contamination is presented, which distinguishes human from local fauna faecal inputs and in situ production in the Antarctic environment. Sewage contamination was detected up to 1.5 km from Davis Station.

The qualitative and quantitative composition of major ions and nutrient compounds in surface waters and soils of the west coast of Admiralty Bay (King George Island, West Antarctica) was investigated together with the effect of soil-forming processes and atmospheric precipitation on the ionic composition of surface waters. In the water bodies studied, Cl- and Na+ were dominant major ions (average concentrations: 1102.2 and 930.9 μM, respectively). Average concentrations of the other major anions ranged from 2.80 μM (F-) to 81.64 μM (SO42-) and major cations ranged from 12.46 μM (K+) to 130.76 μM (Mg2+). Average concentrations of total reactive phosphorus, N-NO2-, N-NO3- and N-NH4+ amounted to 1.374, 0.410, 6.299 and 1.490 μM, respectively. Average concentrations of Ca, Mg, Na, K, N and P in the surface layer of the soil equalled 16.8, 15.9, 6.4, 3.6, 0.646 and 0.744 g kg-1, respectively. The calculated Na+/Cl-, Ca2+/Mg2+, Ca2+/Na+ and HCO3-/Cl- ratios revealed that atmospheric precipitation was the main source of major ions. We conclude that the ionic composition of the waters of the western coast of Admiralty Bay differ from surface waters of Continental Antarctica.

The Adélie penguin (Pygoscelis adeliae) breeding population at Stranger Point, King George Island (25 de Mayo), increased in number from 1965/66 until 1980/81 after which it started to decrease almost continuously up to the present. A significant decrease in the number of breeding pairs and chicks crèched was observed between 1995/96 and 2013/14 (75% and 78%, respectively), although the rate of this decrease has slowed since 2006/07. Over the last seven years, larger interannual fluctuations were recorded in the number of breeding pairs and chicks in crèches, as well in the breeding success. The values for the index of breeding success during 2007/08, 2009/10 and 2012/13 were low and this parameter showed higher temporal fluctuation in the period 2007/08 to 2013/14. The reduction in breeding success and the number of chicks reared to crèche will unfavourably impact on future population size at Stranger Point through the reduction of new recruits. Although Adélie penguin population trends on the Antarctic Peninsula are linked to the marine environment variability (i.e. reduction in sea ice affecting the availability of prey), breeding success is also influenced by the amount of snow fall which has increased in recent years.

The bioremediation of Antarctic soils is a challenge due to the harsh conditions found in this environment. To characterize better the effect of total petroleum hydrocarbon (TPH) concentrations on bacterial, archaeal and microeukaryotic communities in low (LC) and high (HC) hydrocarbon-contaminated soil samples from the Maritime Antarctic clone libraries (small-subunit rRNA genes) were constructed. The results showed that a high concentration of hydrocarbons resulted in a decrease in bacterial and eukaryotic diversity; however, no effect of the TPH concentration was observed for the archaeal community. The HC soil samples demonstrated a high relative abundance of bacterial operational taxonomic units (OTUs) affiliated with unclassified group TM7 and eukaryotic OTUs affiliated with unclassified fungi from Pezizomycotina subphyla. Chemical analyses of the LC and HC soil samples revealed the presence of negligible amounts of nitrogen, thereby justifying the use of biostimulation to remediate these Antarctic soils. Microcosm experiments showed that the application of fertilizers led to an increase of up to 27.8% in the TPH degradation values. The data presented here constitute the first step towards developing the best method to deploy bioremediation in Antarctic soils and provide information to indicate an appropriate action plan for immediate use in the case of new accidents.

In Antarctica, crabeater seals tend to strand as immature animals with disorientation, due to their inexperience, given as the probable cause. In 2012 and 2013, we examined a group of 80 mummified crabeater seals on Seymour Island (Marambio). The age and gender of 28 seals was determined, and virology and stomach content analyses were performed in order to determine the cause of stranding. Around 82% of the seals examined were adults and 79% were females, some of which were pregnant. All of the seals sampled tested negative for Morbillivirus, suggesting that the stranding was not related to the mass mortality event reported in the 1950s in the region. Most seals had empty stomachs and thin blubber suggesting that they died from starvation. The state of the carcasses suggests multiple stranding events. Most of the seals were located along an ice-covered stream, suggesting that this may act as a ‘natural trap’, isolating the seals from the open ocean. This is exceptional as it is the first report of mostly adult female seals to strand in Antarctica and refutes the theory that only young animals are prone to stranding.

Comprehensive geochemical analyses (bulk parameters, major and trace elements, organic matter, mineralogy and particle analysis) were carried out on sediments from seven lakes on Fildes Peninsula, King George Island. The resulting compositional dataset was subjected to principal component analysis and cluster analysis. The results showed that four different lacustrine sedimentary environments can be distinguished: i) lakes 1 and 2 with relatively high values of secondary aluminous clay minerals, ii) lake 4 with anthropogenic enrichment of Co, Cu and Zn, iii) lake 7 with relatively high values of Ba and P and a high zeolite content, and iv) all the other studied lakes. Our results indicate moderate chemical weathering in all lacustrine sediments and that the distance to the glacial ice margin is one of the most important factors influencing the chemical weathering in the area. Furthermore, depositional processes have little influence on the geochemistry of the investigated elements and that local bedrock is the main source of sediments in the lakes on Fildes Peninsula.

This is the first detailed analysis of a CO2 diffuse degassing time series from Deception volcano, South Shetland Islands, Antarctica, performed during an episode of anomalously high long-period (LP) seismicity. Diffuse CO2 emissions measured by an automatic geochemical station between 7 December 2009 and 13 February 2010 showed an excellent temporal agreement with the LP seismicity in December 2009. The absence of such a temporal correlation with the second burst of seismicity that occurred in late January 2010 suggests a different source for this LP activity. This was confirmed by analysis of seismic array data. The LP seismicity observed during December 2009 was caused by fluid-driven cracks that originated from pressure fluctuations in the volcano-hydrothermal systems beneath Deception volcano that were probably caused by a deep injection of undegassed magma before December 2009. The diffuse CO2 degassing data have provided evidence of the activation of at least two different sources of seismicity during the study period at Deception volcano.

Antarctic seaweeds play an important ecological role, but the vast macroalgal beds, typical of the shallow-water zone, are not efficiently grazed. However, macroalgal thalli are covered by epiphytic diatoms which represent a rich food source for higher trophic levels. We describe the abundances, growth form structure, species composition and distribution patterns in the diatom communities associated with Phyllophora antarctica from selected sites within the Ross Sea. The goal of this work was to learn more about the relationships between various components of the epiphytic community and its habitat. To examine diatoms at the microscale, four relatively well described sampling sites were chosen and analyses were performed on a large number of diatoms. All observations and counts were made with the scanning electron microscope. Samples collected in the same season but from different sites and under different sea and ice conditions differed significantly in terms of species composition, but all represented abundant and well-developed diatom communities. A list of species associated with P. antarctica from the investigated area is provided and the influence of the sampling effort on the observed diatom diversity is assessed.

The aim of the study was to determine if soil salt deliquescence and brine hydration can occur under laboratory conditions using natural McMurdo Dry Valleys soils. The experiment was a laboratory analogue for the formation of isolated patches of hypersaline, damp soil, referred to as ‘wet patches’. Soils were oven dried and then hydrated in one of two humidity chambers: one at 100% relative humidity and the second at 75% relative humidity. Soil hydration is highly variable, and over the course of 20 days of hydration, ranged from increases in water content by mass from 0–16% for 122 soil samples from Taylor Valley. The rate and absolute amount of soil hydration correlates well with the soluble salt content of the soils but not with grain size distribution. This suggests that the formation of bulk pore waters in these soils is a consequence of salt deliquescence and hydration of the brine from atmospheric water vapour.

The Ross Sea polynya is one of the most productive regions in the Southern Ocean. However, limited access and high spatio-temporal variability of physical and biological processes limit the use of conventional oceanographic methods to measure early season primary productivity. High-resolution observations from two Seagliders provide insights into the timing of a bloom in the southern Ross Sea polynya in December 2010. Changes in chlorophyll and oxygen concentrations are used to assess bloom dynamics. Using a ratio of dissolved oxygen to carbon, net primary production is estimated over the duration of the bloom showing a sensitive balance between net autotrophy and heterotrophy. The two gliders, observing spatially distinct regions during the same period, found net community production rates of -0.9±0.7 and 0.7±0.4 g C m-2 d-1. The difference highlights the spatial variability of biological processes and is probably caused by observing different stages of the bloom. The challenge of obtaining accurate primary productivity estimates highlights the need for increased observational efforts, particularly focusing on subsurface processes not resolved using surface or remote observations. Without an increased observational effort and the involvement of emerging technologies, it will not be possible to determine the seasonal trophic balance of the Ross Sea polynya and quantify the shelf’s importance in carbon export.

Weddell seals are polar predators that must partition their time between many behaviours, including hunting prey at depth and breathing at the surface. Although they have been well studied, little is known about how foraging behaviour changes when access to breathing holes is restricted, such as in the isolated-hole paradigm. The current study took advantage of previously gathered data for seals diving at an isolated hole to compare with foraging behaviour of free-ranging seals that had access to multiple holes. We examined dive structure, hunting tactics, and allocation of time, locomotor activity and energy based on three-dimensional dive profiles and video imagery of prey encounters for two free-ranging and six isolated-hole seals. Midsummer foraging dives of free-ranging seals were remarkably similar to those of seals diving at an isolated hole, but there were differences in two behavioural states and the frequency of several behavioural transitions. Results indicate that seals employ an energetically more conservative foraging strategy when access to breathing holes is limited and prey are less abundant. These results highlight the importance of understanding the complex interactions between breathing hole access, prey abundance and other factors that may result in different Weddell seal foraging strategies under changing future conditions.

A survey of nearshore areas in the Vestfold Hills, Antarctica, using high-resolution multibeam swath bathymetry provided both a detailed digital bathymetric model and information on sediment acoustic backscatter. Combined with underwater video transects and sediment sampling, these data were used to identify and map geomorphic units. Six geomorphic units identified in the survey region include: rocky outcrops, basins, pediments, valleys, scarps and embayments. In addition to geomorphic units, the data revealed sedimentary features that provide insights into post-glacial sediment transport and erosion in the area. Ice keel pits and scours are common, and sea floor channels, scour depressions and sand ribbons indicate transport and deposition by wind-driven currents and oceanographic circulation. Gullies and sediment lobes observed on steep slopes indicate mass movement of sediment. Some of these processes have not been directly observed to date, but their effectiveness in shaping the modern sea floor is clearly indicated by the sea floor mapping data. The embayments preserve a mantle of boulder sand probably deposited by cold-based glaciers which were flanked by faster-flowing ice in adjoining regions.

It has been demonstrated that persistent organic pollutants (POPs) can affect the immune system of mammals and birds. In this study, the concentration of different POPs and leukocytes in blood samples from three chinstrap penguin (Pygoscelis antarctica) populations was analysed in order to assess the impact on haematological parameters. Using blood sample smears, basophils, eosinophils, heterophils, lymphocytes and monocytes were quantified. Mature and immature red blood cells were counted and cell alterations in both white and red blood cells were analysed. At the same time, whole blood was analysed for POPs. The results showed that contaminants, such as dichlorodiphenyltrichloroethane and its metabolites (ΣDDT), as well as polychlorinated biphenyls (ΣPCB), had significant correlations to eosinophils, lymphocytes and heterophils. This indicates possible immunohaematological alterations derived from exposure to such contaminants. Cytological alterations were also observed, such as cytotoxic granules, toxic heterophils, and atypical and granulated lymphocytes, which would demonstrate that these seabirds are being exposed to stress agents that could be producing some alterations at a leukocytary cellular level.

Polar regions represent a unique environment for the study of mercury cycling in the global ecosystem. Our research was focused on the assessment of the origin and mobility of mercury in the geochemical cycle in Maritime Antarctic (James Ross Island) by means of atomic absorption spectrometry. Mercury content in a set of extrusive (subaerial, subaqueous) and intrusive (dyke) alkaline basalts ranged between 1.6 µg kg-1 (for samples without xenoliths) and 8 µg kg-1 (for samples containing crustal xenoliths). The mercury content in alkaline basalts indicates a very low concentration of mercury in peridotitic mantle sources. Samples of regolith from James Ross Island were subjected to a comprehensive analytical procedure proposed for ultra-trace mercury concentrations involving fractionation and thermal analysis. Total mercury contents in regolith (2.7–11.3 µg kg-1) did not deviate from the natural background in this part of Antarctica. Additionally, the obtained results are about two orders of magnitude smaller than values formerly assumed for primary mercury contents in basaltic lavas. Our results from Antarctica were compared with mercury contents in basaltic rocks from Greenland and the findings were confirmed. It seems that the input of mercury of geological origin into the polar ecosystem is apparently lower than expected.