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Deception Island (DI) is an active volcanic caldera in the South Shetland Islands, Antarctica, with an inner bay, Port Foster, formed by an ancient eruption. The bay's seafloor hydrofracture system contains hydrothermal seeps and submarine vents, which are a source of trace metals (TMs) like Fe, Ni, Co, V, and greenhouse gases (GHGs) such as CO2 and CH4. This study presents measurements of TMs and GHGs in Port Foster's surface waters during January-February 2021 to characterize their spatial distribution. TMs concentrations in the northeastern region of the bay, particularly V (74 nM), Fe (361 nM), Co (3.9 nM) and Ni (17.2 nM), were generally higher than in the Southern Ocean, likely due to hydrothermal activity. As some TMs such as Fe are scarce in the SO and limit primary productivity, inputs of these nutrients from DI into surrounding waters may also regionally promote increased primary productivity. Higher surface temperature (ST), elevated partial pressure of CO2 (pCO2), and lower salinity were found near submarine fumaroles, with ST positively correlated with pCO2 and negatively with salinity. Although hydrothermal sites showed localized CO2 outgassing, the bay overall acted as a CO2 sink, with a median flux of -2.78 mol m-2 yr-1 with an interquartile range (IQR) of 3.84 mol m-2 yr-1. CH4 highest concentration levels were found in the southeastern sector. The median concentration was 8.9 nM with an IQR of 1.9 nM, making Port Foster a regional net CH4 source with a median flux of 9.7 μmol m-2 d-1 and an IQR of 3.4 μmol m-2 d-1. Ultimately, the analysis of spatial patterns of the measured variables suggested that fumaroles of DI may be playing a significant role in the alteration of regional seawater biogeochemistry. [ABSTRACT FROM AUTHOR]

Organic and inorganic cyanides are widely distributed in nature, yet not much is known about the ability of microorganisms to use these compounds as a source of nitrogen and/or carbon at high temperatures (>80 °C). Here we studied the capacity of organic and inorganic cyanides to support growth of an hyperthermophilic Pyrococcus strain isolated from Deception Island, Antarctica. This microorganism was capable of growing with aromatic nitriles, aliphatic nitriles, heterocyclic nitriles, amino aromatic nitriles and inorganic cyanides as nitrogen and/or carbon source. This is the first report of an hyperthermophilic microorganism able to incorporate these compounds in its nitrogen and carbon metabolism. Based on enzymatic activity and genomic information, it is possibly that cells of this Pyrococcus strain growing with nitriles or cyanide, might use the carboxylic acid and/or the ammonia generated through the nitrilase enzymatic activity, as a carbon and/or nitrogen source respectively. This work expands the temperature range at which microorganisms can use organic and inorganic cyanides to growth, having important implications to understand microbial metabolisms that can support life on Earth and the possibility to support life elsewhere. [ABSTRACT FROM AUTHOR]

Deception Island (DI) is an active volcanic caldera in the South Shetland Islands, Antarctica, with an inner bay, Port Foster, formed by an ancient eruption. The bay’s seafloor hydrofracture system contains hydrothermal seeps and submarine vents, which are a source of trace metals (TMs) like Fe, Ni, Co, V, and greenhouse gases (GHGs) such as CO2 and CH4. This study presents measurements of TMs and GHGs in Port Foster’s surface waters during January-February 2021 to characterize their spatial distribution. TMs concentrations in the northeastern region of the bay, particularly V (74 nM), Fe (361 nM), Co (3.9 nM) and Ni (17.2 nM), were generally higher than in the Southern Ocean, likely due to hydrothermal activity. As some TMs such as Fe are scarce in the SO and limit primary productivity, inputs of these nutrients from DI into surrounding waters may also regionally promote increased primary productivity. Higher surface temperature (ST), elevated partial pressure of CO2 (pCO2), and lower salinity were found near submarine fumaroles, with ST positively correlated with pCO2 and negatively with salinity. Although hydrothermal sites showed localized CO2 outgassing, the bay overall acted as a CO2 sink, with a median flux of -2.78 mol m-2 yr-1 with an interquartile range (IQR) of 3.84 mol m-2 yr-1. CH4 highest concentration levels were found in the southeastern sector. The median concentration was 8.9 nM with an IQR of 1.9 nM, making Port Foster a regional net CH4 source with a median flux of 9.7 μmol m-2 d-1 and an IQR of 3.4 μmol m-2 d-1. Ultimately, the analysis of spatial patterns of the measured variables suggested that fumaroles of DI may be playing a significant role in the alteration of regional seawater biogeochemistry.

There is a single record of the rare terrestrial nematode genus Acunemella Andrássy, 2002 (Nematoda, Nordiidae) in the type locality on Chiloé Island (South Chile). The type species of the genus, Acunemella torta Andrássy, 2002, was described on the basis of only two male specimens. In this article, mature females of the genus Acunemella are described for the first time based on morphology and morphometrics of specimens from Deception Island (South Shetland Islands). The current article is the first report of this genus from the Antarctic region. Females from Deception Island are characterized by a didelphic-amphidelphic genital system, with both branches almost equally developed, a distinct muscular sphincter between oviduct and uterus, a curling outer surface of the uterus, pars refringens vaginae moderately sclerotized, with two relatively large (4–6 × 12–13 μm) rounded triangular pieces, a vulval region with well-developed cuticular folds. Morphologically, females are similar to originally described males but differ by longer bodies, more distinctly offset lip regions and the shape of sperm cells in uterus. Verifying the taxonomic status of the population described in this article requires the analysis of additional materials.

Endolithic microorganisms, ranging from microeukaryotes to bacteria and archaea, live within the cracks and crevices of rocks. Deception Island in Antarctica constitutes an extreme environment in which endoliths face environmental threats such as intense cold, lack of light in winter, high solar radiation in summer, and heat emitted as the result of volcanic eruptions. In addition, the endolithic biome is considered the harshest one on Earth, since it suffers added threats such as dryness or lack of nutrients. Even so, samples from this hostile environment, collected at various points throughout the island, hosted diverse and numerous microorganisms such as bacteria, fungi, diatoms, ciliates, flagellates and unicellular algae. These endoliths were first identified by Scanning Electron Microscopy (SEM). To understand the molecular mechanisms of adaptation of these endoliths to their environment, genomics techniques were used, and prokaryotic and eukaryotic microorganisms were identified by metabarcoding, sequencing the V3–V4 and V4–V5 regions of the 16S and 18S rRNA genes, respectively. Subsequently, the sequences were analyzed by bioinformatic methods that allow their metabolism to be deduced from the taxonomy. The results obtained concluded that some of these microorganisms have activated the biosynthesis routes of pigments such as prodigiosin or flavonoids. These adaptation studies also revealed that microorganisms defend themselves against environmental toxins by activating metabolic pathways for the degradation of compounds such as ethylbenzene, xylene and dioxins and for the biosynthesis of antioxidant molecules such as glutathione. Finally, these Antarctic endolithic microorganisms are of great interest in astrobiology since endolithic settings are environmentally analogous to the primitive Earth or the surfaces of extraterrestrial bodies. [ABSTRACT FROM AUTHOR]

There is a single record of the rare terrestrial nematode genus Acunemella Andrássy, 2002 (Nematoda, Nordiidae) in the type locality on Chiloé Island (South Chile). The type species of the genus, Acunemella torta Andrássy, 2002, was described on the basis of only two male specimens. In this article, mature females of the genus Acunemella are described for the first time based on morphology and morphometrics of specimens from Deception Island (South Shetland Islands). The current article is the first report of this genus from the Antarctic region. Females from Deception Island are characterized by a didelphic-amphidelphic genital system, with both branches almost equally developed, a distinct muscular sphincter between oviduct and uterus, a curling outer surface of the uterus, pars refringens vaginae moderately sclerotized, with two relatively large (4-6 x 12-13 µm) rounded triangular pieces, a vulval region with well-developed cuticular folds. Morphologically, females are similar to originally described males but differ by longer bodies, more distinctly offset lip regions and the shape of sperm cells in uterus. Verifying the taxonomic status of the population described in this article requires the analysis of additional materials. [ABSTRACT FROM AUTHOR]

Endolithic microorganisms, ranging from microeukaryotes to bacteria and archaea, live within the cracks and crevices of rocks. Deception Island in Antarctica constitutes an extreme environment in which endoliths face environmental threats such as intense cold, lack of light in winter, high solar radiation in summer, and heat emitted as the result of volcanic eruptions. In addition, the endolithic biome is considered the harshest one on Earth, since it suffers added threats such as dryness or lack of nutrients. Even so, samples from this hostile environment, collected at various points throughout the island, hosted diverse and numerous microorganisms such as bacteria, fungi, diatoms, ciliates, flagellates and unicellular algae. These endoliths were first identified by Scanning Electron Microscopy (SEM). To understand the molecular mechanisms of adaptation of these endoliths to their environment, genomics techniques were used, and prokaryotic and eukaryotic microorganisms were identified by metabarcoding, sequencing the V3–V4 and V4–V5 regions of the 16S and 18S rRNA genes, respectively. Subsequently, the sequences were analyzed by bioinformatic methods that allow their metabolism to be deduced from the taxonomy. The results obtained concluded that some of these microorganisms have activated the biosynthesis routes of pigments such as prodigiosin or flavonoids. These adaptation studies also revealed that microorganisms defend themselves against environmental toxins by activating metabolic pathways for the degradation of compounds such as ethylbenzene, xylene and dioxins and for the biosynthesis of antioxidant molecules such as glutathione. Finally, these Antarctic endolithic microorganisms are of great interest in astrobiology since endolithic settings are environmentally analogous to the primitive Earth or the surfaces of extraterrestrial bodies.

Deception Island is one of the most active and best‐documented volcanoes in Antarctica. Since its last eruption in 1970, several geophysical surveys have targeted reconstructing its magmatic systems. However, geophysics fails to reconstruct the pathways magma and fluids follow from depth to erupt at the surface. Here, novel data selection strategies and multi‐frequency absorption inversions have been framed in a Geographical Information System, using all available geological (vents and faults distribution), geochemical and geophysical knowledge of the volcano. The result is the detection of these eruptive pathways. The model offers the first image of the magma and associated fluids pathways feed the 1967, 1969, and 1970 eruptions. Results suggest that future ascending paths might lead to active research bases and zones of planned helicopter rescue. The connection between seismic absorption, temperature, and fluid content makes it a promising attribute for detecting and monitoring eruptions at active calderas. Plain Language Summary: Deception Island is the gateway for tourists to Antarctica and a laboratory to understand ice‐capped volcanoes and their eruptions. While the Island has been the target of many geophysical studies, no clear tomographic model shows how deep eruptive pathways of its last eruptions have reached the surface in the 1960s and 1970s. This is a recurrent topic in volcano geophysics: dikes and fluid migrations develop across structures considered too small to be detected by tomographic techniques. This paper demonstrates that seismic absorption has sufficient sensitivity to temperature and fluid content to detect these pathways. Once integrated within a Geographical Information System with all the information we have on the volcano, the models resolve the feeding systems of these eruptions, from a tectonically deformed deep magma chamber to shallow cold dyke intrusions and fluid migrations still feeding the volcano today. The correlation between seismic absorption, temperature, and fluid content offers a new tool for detecting and monitoring shallow volcanic hazards. Key Points: High absorption detects deep eruptive pathways from the caldera center to its rimAbsorption imaging reconstructs shallow pathways of hazardous materialsSeismic absorption is sensitive to thermal anomalies at depth [ABSTRACT FROM AUTHOR]

The biotechnological potential for agricultural applications in the soil in the thawing process on Whalers Bay, Deception Island, Antarctica was evaluated using a metagenomic approach through high-throughput sequencing. Approximately 22.70% of the sequences were affiliated to the phyla of the Bacteria dominion, followed by 0.26% to the Eukarya. Proteobacteria (Bacteria) and Ascomycota (Fungi) were the most abundant phyla. Thirty-two and thirty-six bacterial and fungal genera associated with agricultural biotechnological applications were observed. Streptomyces and Pythium were the most abundant genera related to the Bacteria and Oomycota, respectively. The main agricultural application associated with bacteria was nitrogen affixation; in contrast for fungi, was associated with phytopathogenic capabilities. The present study showed the need to use metagenomic technology to understand the dynamics and possible metabolic pathways associated with the microbial communities present in the soil sample in the process of thawing recovered from the Antarctic continent, which presented potential application in processes of agro-industrial interest., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Deception Island is an active volcano located in the South Shetland Islands, Antarctica. Although the last eruptions occurred in 1967-1970, the volcano has undergone periods of seismic unrest in 1992, 1999, and 2015. In this work, we analyze continuous seismic data obtained by a permanent station for the period 2008-2015 preceding the 2015 unrest. We identify different types of seismic signals including tectonic and volcano-tectonic (VT) earthquakes and long-period (LP) seismicity, using a combination of visual and automated techniques. The temporal evolution of the seismicity displays three differentiated stages. In Phase 1 (2008-2010) the volcano was in a dormant state characterized by a moderate level of seismicity dominated by low-energy LP seismicity, and very few VT earthquakes. In Phase 2 (2011-2014), there was a gradual increase in the level of LP events and tremor, and an acceleration of the number and energy of VT earthquakes. In Phase 3 (2014-2015) the seismicity reached a climax, with the occurrence of seismic swarms comprising thousands of earthquakes, displaying maximum activity in September-October 2014 and February 2015. We propose that the change from Phase 1 to Phase 2 was due to the recharge of magma into the plumbing system at Moho depths. The emplacement of fresh magma increased the amount of gas (and heat) permeating the volcano edifice, triggering VT earthquakes in brittle regions and favoring the occurrence of LP seismicity in the shallow hydrothermal system. During Phase 2 magma ascended through the plumbing system, as evidenced by the acceleration of the seismicity rates, the detection of thermal anomalies, and a change in the deformation pattern that for 2013-2015 corresponded to an inflation process. Finally, in Phase 3 the magma intrusion reached its shallowest point before stalling at a depth of 6-10 km. The stress perturbations propagated through crustal fluids and produced a distal VT swarm SE of Livingston, as well as proximal VT swarms and very intense LP seismicity at Deception Island. [ABSTRACT FROM AUTHOR]

Antarctic lakes have generally simple periphyton communities when compared with those of lower latitudes. To date, assessment of microbial diversity in Antarctica has relied heavily on traditional direct observation and cultivation methods. In this study, sterilized cotton baits were left submerged for two years in two lakes on King George Island and Deception Island, South Shetland Islands (Maritime Antarctic), followed by assessment of diversity by metabarcoding using high-throughput sequencing. DNA sequences of 44 taxa belonging to four kingdoms and seven phyla were found. Thirty-six taxa were detected in Hennequin Lake on King George Island and 20 taxa were detected in Soto Lake on Deception Island. However, no significant difference in species composition was detected between the two assemblages (Shannon index). Our data suggest that metabarcoding provides a suitable method for the assessment of periphyton biodiversity in oligotrophic Antarctic lakes. [ABSTRACT FROM AUTHOR]

Parent–offspring conflict theory predicts that offspring seek to prolong the parental care period, while parents strive to shorten it as much as possible. Transition to the crèche phase in penguins involves changes in the dynamic of parental investment in chicks, and thus may be modulated by interests that benefit parent or offspring. We explored parent–offspring interactions in the Chinstrap Penguin (Pygoscelis antarctica) to understand the influence such interactions would have on transition to crèche phase. We studied the effect of hatching date, nestling age, brood size, and nest location on parent–offspring interactions and the length of the guard phase. All behavioral variables related to nestling demands for parental investment increased as well as parental aggression towards their chicks, with increased nestling age. Brood size showed significant effects on both nestling and parental behavior. Hatching date was negatively correlated with the age at crèche. Consequently, the decision to leave the chicks unguarded seemed to be more based on the condition of adults rather than of the chicks. Given the short time available for breeding in Antarctica and that penguins are long-lived birds with several opportunities to breed, there may be conflicting selective factors between investment in feeding chicks versus extending the period of resource acquisition and storage prior to moult. [ABSTRACT FROM AUTHOR]

Variations in mineralogical and elemental composition of Turbic Cryosol (King George Island and James Ross Island), Skeletic Cryosol (J. Ross Island, the Trinity Peninsula), Leptic Andosols (Deception Island), and Skeletic Andosols (Deception Island) were studied. Significant differences in mineralogical composition in size fraction, vertical and horizontal position were determined by X-ray diffraction quantitative analysis. The differences were attributed to a variable degree of chemical weathering process. As a product of weathering were defined montmorillonite, chlorite, microcrystalline polymorphous silica, Fe oxides, and oxyhydroxides. Their content was increased towards the surface and in a finer fraction. Crystal thickness and size distribution of montmorillonite was measured by the Bertaut-Warren-Averbach technique and the results confirmed higher intensity of chemical weathering in Turbic Cryosols (J. Ross Island and King George Island). Feldspars and volcanic glass were the main phases found in soil samples from Deception Island. They were determined as phases of parent rock and indicated low intensity of chemical weathering. Clinoptilolite was identified in soil samples from J. Ross Island and Deception Islad and its hydrothermal origin was supposed. Soil (sample AP) from Base General Bernardo O'Higgins Riquelme had significantly higher content of phosphate minerals, which was a result of ornithogenic activities. Macro elements content was consistent with mineralogical analyses. Turbic Cryosols were rich in iron, aluminium, magnesium, and manganese (> 2%). Skeletic Cryosols contained also iron, aluminium, magnesium, manganese, calcium, and sulphur (> 1%). Leptic Andosols were rich in iron and aluminium (> 2%). Soil properties and humic substances quality were evaluted. Results of chemical and physical analyses indicated that poorly developed soils of Antarctica varied in acidity, conductivity, humus content, and texture. Humic substances content and quality were low. Mainly mechanical (physical) and chemical weathering processes played major role in the soil development accompanied by low intensity of biological activity.

Substrate–atmosphere interfaces in Antarctic geothermal environments are hot–cold regions that constitute thin habitable niches for microorganisms with possible counterparts in ancient Mars. Cerro Caliente hill in Deception Island (active volcano in the South Shetland Islands) is affected by ascending hydrothermal fluids that form a band of warm substrates buffered by low air temperatures. We investigated the influence of temperature on the community structure and metabolism of three microbial mats collected along the geothermal band of Cerro Caliente registering 88°C, 8°C, and 2°C at the time of collection. High-throughput sequencing of small subunit ribosomal ribonucleic acid (SSU rRNA) genes and Life Detector Chip (LDChip) microarray immunoassays revealed different bacterial, archaeal, and eukaryotic composition in the three mats. The mat at 88°C showed the less diverse microbial community and a higher proportion of thermophiles (e.g., Thermales). In contrast, microbial communities in the mats at 2°C and 8°C showed relatively higher diversity and higher proportion of psychrophiles (e.g., Flavobacteriales). Despite this overall association, similar microbial structures at the phylum level (particularly the presence of Cyanobacteria) and certain hot- and cold-tolerant microorganisms were identified in the three mats. Daily thermal oscillations recorded in the substrate over the year (4.5–76°C) may explain the coexistence of microbial fingerprints with different thermal tolerances. Stable isotope composition also revealed metabolic differences among the microbial mats. Carbon isotopic ratios suggested the Calvin–Benson–Bassham cycle as the major pathway for carbon dioxide fixation in the mats at 2°C and 8°C, and the reductive tricarboxylic acid cycle and/or the 3-hydroxypropionate bicycle for the mat at 88°C, indicating different metabolisms as a function of the prevailing temperature of each mat. The comprehensive biomarker profile on the three microbial mats from Cerro Caliente contributes to unravel the diversity, composition, and metabolism in geothermal polar sites and highlights the relevance of geothermal-cold environments to create habitable niches with interest in other planetary environments. [ABSTRACT FROM AUTHOR]

Abstract The present work reports on the analysis of atmospheric aerosols in the Antarctic region, Deception Island, collected during austral summer 2016–2017 by field measurements carried from Gabriel de Castilla Spanish Research Station. A low-volume sampler was used to capture the aerosols depositing them onto the air filters. A chemical analysis of the samples using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) provided the total carbon (TC), organic carbon (OC), elemental Carbon (EC) and elements such as Al, Ca, Fe, K, Mg, Na, P, S, Cu, Pb, Sr, Ti, Zn and Cr. The average mass concentration of particulate matter (PM 10) originated by natural and anthropogenic activities was calculated as 10 ± 4 μg/m3, although values such as 28.2 μg/m3 were also obtained which is very high even when compared to other places in the coast of the Antarctic region. In addition, high enrichment factors have been found for elements such as Pb, Cr, Cu and Zn showing a remote anthropogenic contribution to particulate matter in this region. Correlations were found between Na, Mg, Ca, Al, Ti and S, where Na/Mg displayed the influence of marine environments, S correspond to volcanic activities, Ca to penguin colonies and influence of sea whereas Al/Ti indicated the crustal origin. Polar contour graphical maps were obtained from meteorological data using chemometrics methods, which allowed reproducing wind maps revealing the distribution of the aerosols and possible emission sources of different elements in the area. Given that this island has not been previously studied for atmospheric contamination, this work provides an interesting insight about the site-specific characteristics of particulate matter. Graphical abstract Unlabelled Image Highlights • Particulate matter PM 10 in Antarctic region (Deception Island) was analyzed. • Low volume sampler was used to capture the aerosol particles (PM 10). • Enrichment factors of Pb, Cr, Cu and Zn were calculated. • Statistical tools were used to establish the correlations between the elements. • Polar Contour Maps were used to determine the origin of pollutants [ABSTRACT FROM AUTHOR]

Abstract Due to its biomagnification mercury (Hg) is an element of concern especially in the remote pristine ecosystems such as Antarctica. Despite the sensitivity of the region, there is still a limited knowledge about the influence of natural processes, i.e. volcanism, climate, atmospheric mercury depletion events or freeze-thawing cycles, on the Hg cycle in Antarctica. We analysed total Hg and solid phase Hg species (Hg-thermo–desorption-AAS) in 1600 years old sediments from Limnopolar Lake (Byers Peninsula, South Shetland Islands). Some sections of the core show unusual high Hg concentrations (1141–11286 ng g−1) and accumulation rates (310–4902 µg m−2 yr−1). Hg-thermo-desorption analyses indicate that Hg is bound in the sediment by organic matter of different degree of degradation. We propose a combination of different natural processes to explain the high enrichment of Hg in the sediments. The nearby (30 km) Deception Island volcano appears to be the main source of Hg, while climatic conditions have controlled freezing-thawing of the ice-cover and the enrichment of Hg in the snowpack on the frozen lake (and its catchment). The release of Hg from the snowpack during thawing events appears to cause the extreme Hg enrichment in the sediments. The global atmospheric pollution is a minority signal in our record. The ∼2.2 fold increase in Hg concentrations since AD ∼ 1860 points industrial activities as the unique pollution cause. Our findings indicate that thawing of Antarctic ice might release large quantities of Hg to freshwater and marine systems and related food chains. [ABSTRACT FROM AUTHOR]

Polar volcanoes harbor unique conditions of extreme temperature gradients capable of selecting different types of extremophiles. Deception Island is a marine stratovolcano located at Maritime Antarctica that is notable for its pronounced temperature gradients over very short distances, reaching values up to 100 °C in the fumaroles, and subzero temperatures next to the glaciers. Due to these characteristics, Deception can be considered an interesting analogue of extraterrestrial environments. Our main goal in this study was to isolate thermophilic and psychrophilic bacteria from sediments associated with fumaroles and glaciers from two geothermal sites in Deception Island, comprising temperatures between 0 and 98 °C, and to evaluate their survivability to desiccation and UV-C radiation. Our results revealed that culturable thermophiles and psychrophiles were recovered among the extreme temperature gradient in Deception volcano, which indicates that these extremophiles remain alive even when the conditions do not comprise their growth range. The viability of culturable psychrophiles in hyperthermophilic environments is still poorly understood and our work showed the importance of future studies about their survival strategies in high temperatures. Finally, the spore-forming thermophilic isolates which we found have displayed good survival to desiccation and UV-C irradiation, which suggests their potential to be further explored in astrobiological studies. [ABSTRACT FROM AUTHOR]

Quantification of suspended particulate matter (SPM) measurements—together with statistical tools, polar contour maps and backward air mass trajectory analyses—were implemented to better understand the main local and remote sources of contamination in this pristine region. Field campaigns were carried out during the austral summer of 2016–2017 at the “Gabriel de Castilla” Spanish Antarctic Research Station, located on Deception Island (South Shetland Islands, Antarctic). Aerosols were deposited in an air filter through a low-volume sampler and chemically analysed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). Elements such as Al, Ca, Fe, K, Mg, Na, P, S, Cu, Pb, Sr, Ti, Zn, Hf, Zr, V, As, Ti, Mn, Sn and Cr were identified. The statistical tools together with their correlations (Sr/Na, Al/Ti, Al/Mn, Al/Sr, Al/Pb, K/P) suggest a potentially significant role of terrestrial inputs for Al, Ti, Mn, Sr and Pb; marine environments for Sr and Na; and biological inputs for K and P. Polar contour graphical maps allowed reproducing wind maps, revealing the biological local distribution of K and P (penguin colony). Additionally, backward trajectory analysis confirmed previous affirmations and atmospheric air masses following the Antarctic circumpolar pattern.

Variations in mineralogical and elemental composition of Turbic Cryosol (King George Island and James Ross Island), Skeletic Cryosol (J. Ross Island, the Trinity Peninsula), Leptic Andosols (Deception Island), and Skeletic Andosols (Deception Island) were studied. Significant differences in mineralogical composition in size fraction, vertical and horizontal position were determined by X-ray diffraction quantitative analysis. The differences were attributed to a variable degree of chemical weathering process. As a product of weathering were defined montmorillonite, chlorite, microcrystalline polymorphous silica, Fe oxides, and oxyhydroxides. Their content was increased towards the surface and in a finer fraction. Crystal thickness and size distribution of montmorillonite was measured by the Bertaut-Warren-Averbach technique and the results confirmed higher intensity of chemical weathering in Turbic Cryosols (J. Ross Island and King George Island). Feldspars and volcanic glass were the main phases found in soil samples from Deception Island. They were determined as phases of parent rock and indicated low intensity of chemical weathering. Clinoptilolite was identified in soil samples from J. Ross Island and Deception Islad and its hydrothermal origin was supposed. Soil (sample AP) from Base General Bernardo O'Higgins Riquelme had significantly higher content of phosphate minerals, which was a result of ornithogenic activities. Macro elements content was consistent with mineralogical analyses. Turbic Cryosols were rich in iron, aluminium, magnesium, and manganese (> 2%). Skeletic Cryosols contained also iron, aluminium, magnesium, manganese, calcium, and sulphur (> 1%). Leptic Andosols were rich in iron and aluminium (> 2%). Soil properties and humic substances quality were evaluted. Results of chemical and physical analyses indicated that poorly developed soils of Antarctica varied in acidity, conductivity, humus content, and texture. Humic substances content and quality were low. Mainly mechanical (physical) and chemical weathering processes played major role in the soil development accompanied by low intensity of biological activity. [ABSTRACT FROM AUTHOR]

Oxygen ( 16 O, 17 O and 18 O) and sulfur ( 32 S, 33 S, 34 S and 36 S) isotope ratios of and major ion (Na + , Ca 2 + , Cl − , NO 3 − and SO 4 2 − ) concentrations in lakes, ponds and creeks from Deception Island, Antarctic Peninsula were analyzed to study the sources of sulfate, its oxidation, and the surficial processes of the dissolved sulfate. The positive relationship between the δ 34 S sulfate (8.1‰ to 17.3‰) and the Cl − /SO 4 2 − molar ratio suggests mixing of sulfate from atmospheric deposition and from oxidation of sulfide minerals. The average sea salt fraction (28%) and δ 34 S nss values (from 5.6‰ to 15.9‰) indicate that a combination of sea salt and marine biogenic sulfide provide the high δ 34 S end-member of the dissolved sulfates. The relatively low δ 18 O sulfate (from − 4.6‰ to 0.7‰) of Deception Island water suggests a role of local water in the formation of sulfate. Slightly negative but mass-dependent Δ 17 O sulfate values imply that atmospheric oxidation by O 3 and H 2 O 2 are negligible, while these values might suggest a significant role of oxidation by molecular oxygen and OH. The distinctly low δ 34 S sulfate value of two samples (DCW-2 and DCW-3) suggests the input of sulfate from sulfide oxidation. Slight elevation of δ 34 S sulfate values up to 17.3‰ compared to a typical atmospheric value indicates a minimal role for dissimilatory microbial sulfate reduction of Deception Island water and sediments. Both Δ 33 S sulfate and Δ 36 S sulfate values are homogeneous and near zero, implying that the dominant atmospheric oxidation process is tropospheric and that there are minimal to no contributions of stratospheric sulfate to Deception Island water. [ABSTRACT FROM AUTHOR]

The dorvilleid polychaeteOphryotrocha orensanziis reported from the vicinity of Casey station, East Antarctica, an astounding range extension from its previous records in the South Shetland Islands to the opposite side of the Antarctic continent, suggesting that it is a circumpolar species. Genetic studies confirmed the conspecificity and the inferred haplotype network suggests that the two populations studied are genetically connected. Morphological studies of the newly collected material revealed that the jaw apparatus consists of the P- and K-type, in accordance with other members of the ‘lobifera’ clade. We are reporting a previously undocumented button-like structure that we are referring to as ‘nuchal papilla’ for its association with the nuchal region, and present an emended diagnosis for the species. The Casey station population was collected in a clean, unpolluted intertidal environment associated with stones and seaweeds. We are challenging the generally held opinion thatOphryotrochaspecies are specialists of organically enriched substrates, suggesting that, at least for the particulars ofO. orensanzi, they might also be unspecialized opportunists, able to exist in the most pristine environments and having the ability to rapidly increase their population sizes under favourable conditions. [ABSTRACT FROM AUTHOR]

Tephra layers preserved in lake sedimentary sequences provide valuable isochrons with which to synchronise palaeoclimatic records. However, in regions where tephra inputs are dominated by a single volcanic source, overlapping chemical compositions can preclude unambiguous correlation of tephra layers. In this study, we characterise multiple visible (macrotephra) layers within sedimentary sequences from three lakes in Byers Peninsula, Antarctica. By combining compositional analyses with additional constraints from textural componentry, we identify three distinct tephra isochrons—T1, T2, and T3—each with distinct textural properties. The relative proportion of glassy compared to crystal-rich grains varies from ~ 50% (T3) to ~ 3% (T1) of the total sample. Although the proportion of dense to vesicular grains differs only slightly between all sampled tephra layers, the dominant vesicle shape varies from spherical (T3) to irregular and polylobate (T1/T2). These textural differences can be related to variations in the eruptive processes occurring at the Deception Island source volcano. This study highlights the efficacy of a correlative approach based on both chemical and physical tephra properties for deconvolving the tephra stratigraphy in regions where chemical compositions are non-unique. [ABSTRACT FROM AUTHOR]

This is the first reported case of Babesia sp. in Antarctic penguins, specifically a population of Chinstrap penguins ( Pygoscelis antarctica ) in the Vapour Col penguin rookery in Deception Island, South Shetlands, Antarctica. We collected peripheral blood from 50 adult and 30 chick Chinstrap penguins. Examination of the samples by microscopy showed intraerythrocytic forms morphologically similar to other avian Babesia species in 12 Chinstrap penguin adults and seven chicks. The estimated parasitaemias ranged from 0.25 × 10 −2 % to 0.75 × 10 −2 %. Despite the low number of parasites found in blood smears, semi-nested PCR assays yielded a 274 bp fragment in 12 of the 19 positive blood samples found by microscopy. Sequencing revealed that the fragment was 97% similar to Babesia sp. 18S rRNA from Australian Little Penguins ( Eudyptula minor ) confirming presence of the parasite. Parasite prevalence estimated by microscopy in adults and chicks was higher (24% vs. 23.3%, respectively) than found by semi-nested PCR (16% vs. 13.3% respectively). Although sampled penguins were apparently healthy, the effect of Babesia infection in these penguins is unknown. The identification of Babesia sp. in Antarctic penguins is an important finding. Ixodes uriae , as the only tick species present in the Antarctic Peninsula, is the key to understanding the natural history of this parasite. Future work should address the transmission dynamics and pathogenicity of Babesia sp. in Chinstrap penguin as well as in other penguin species, such as Gentoo penguin ( Pygoscelis papua ) and Adélie penguin ( Pygoscelis adeliae ), present within the tick distribution range in the Antarctic Peninsula. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]