Penguin Island Research Articles

Marine heatwaves affect breeding, diet and population size but not body condition of a range-edge little penguin colony

Significant marine heatwaves (MHWs) developed along the Western Australian coast in 1999 and 2011. Despite ecosystem losses and the southwards occurrence of many tropical fish species during and after the extreme MHW in 2011, there have been few studies on the effects of this MHW on seabirds, and no biological impacts related to the 1999 MHW have been reported. Using data from 1986-2019, we investigated the impacts of these events on breeding outcomes, body condition, diet composition, population size and mortality of little penguins on Penguin Island, in the temperate waters off Western Australia. Breeding outcomes were negatively impacted by the MHWs but body condition was not. Diet composition changed after the MHW, with sandy sprat Hyperlophus vittatus, the penguins’ typical major prey component, replaced by scaly mackerel Sardinella lemuru, a tropical fish species. Using an open robust design analysis that accounts for imperfect capture probabilities and staggered annual arrival and departure dates, we found that the population decreased by 80% following the 2011 MHW. Finally, more penguins died from starvation or from novel protozoal parasitic infections in 2011 and 2012 that were potentially introduced with the changed diet. This research highlights that the temporal and spatial influence of MHWs on seabirds depends on several factors. Furthermore, the magnitude and direction of a prey species’ response can be very localised and have significant impacts on avian predators. There are no obvious ways to mediate climate effects, but perhaps measures taken to reduce any synergistic impacts on prey abundance, particularly during MHW events, could be effective.

The 1821 eruption of Bridgeman Island, South Shetland Islands, Antarctica: an observed Capelinhos-style hydrovolcanic event

AbstractThe first recorded volcanic eruption in Antarctica occurred on Bridgeman Island (South Shetland Islands) in early 1821, < 2 years after Antarctica was discovered. However, the observations were disputed owing to a lack of physical evidence. A consensus arose that they probably referred to Penguin Island, a young volcano with a well-formed volcanic cone situated just 60 km to the west. However, a recent re-examination of the historical reports demonstrated that the event was undoubtedly located at Bridgeman Island. Our new study demonstrates that the eruption was explosive and lasted throughout 1821. The vent was situated in the sea ~500 m to the west of Bridgeman Island and the eruption was hydrovolcanic (Surtseyan). The new volcano constructed a tuff ring composed of unconsolidated lapilli and ash, which rapidly coalesced with nearby Bridgeman Island, similar to how the Capelinhos volcano joined with neighbouring Faial (Azores) in 1957–1958. The tuff ring had a very low profile and was rapidly removed by marine erosion. However, fumarolic activity persisted for a few decades. Because the eruption is only 200 years old, the underlying volcanic construct (Bridgeman Rise) should be regarded as dormant rather than extinct.

Fatal toxoplasmosis in Little Penguins (Eudyptula minor) from Penguin Island, Western Australia.

Routine post mortems of deceased penguins from Penguin Island, Western Australia, found that a temporal cluster of cases presented with characteristic gross and microscopic changes, namely birds in good body condition with hepatomegaly and splenomegaly, multifocal hepatic and splenic necrosis and numerous, 1–2 μm diameter protozoan parasites within the necrotic foci.Electron microscopy identified the protozoa as belonging to the phylum Apicomplexa. Molecular investigations by PCR gave inconsistent results. PCR performed by an external laboratory identified a novel Haemoproteus spp. organism in samples from 4 of 10 cases from this group, while PCR at Murdoch University identified Toxoplasma gondii in 12 of 13 cases (including 9 of the 10 assayed at the external laboratory). Immunohistochemistry of formalin fixed tissues also identified Toxoplasma in the hepatic and splenic lesions.The distinctive mortalities which were observed in this group of penguins are attributed to a fulminant toxoplasmosis, with a concurrent Haemoproteus infection in some cases. Though the clinical signs of infection are unknown, the gross and microscopic appearance at post mortem is sufficiently characteristic to allow a diagnosis to be made on these features. Definitive confirmation of Toxoplasma infection can be made by immunohistochemistry or PCR.

ԱՅԼԱԲԱՆԱԿԱՆ ՎԵՊԻ ՀԱՄԵՄԱՏԱԿԱՆ ՎԵՐԼՈՒԾՈՒԹՅՈՒՆ. ԱՆԱՏՈԼ ՖՐԱՆՍ ԵՎ ՖՐԱՆՍՈՒԱ ՌԱԲԼԵ (Ա.Ֆրանսի «Պինգվինների կղզին» և Ֆ.Ռաբլեի «Գարգանտյուա և Պանտագրյուել» վեպերի նյութի հիման վրա) / COMPARATIVE ANALYSIS OF THE ALLEGORICAL NOVEL: ANATOLE FRANZ AND FRANCOIS RABELAIS (BASED ON THE NOVELS "PENGUIN ISLAND" BY A. FRANZ AND "GARGANTUA AND PANTAGRUEL" BY F. RABELAIS)

The novel “Penguin Island” by Anatole Franz presents almost all stages of French society and the history of civilization through satirical and allegorical paintings. When writing his novel, Anatole Franz was inspired by the novel Gargantua and Pantagruel by F. Rabelais. In the novel by Anatole Franz, real historical figures are hidden under the fictitious names of the characters, and in the novel by Rabelais, the names of the characters have an allegorical meaning, symbolizing the ideas of advanced humanity of the Renaissance, embodying the aspirations and desires of the author regarding the changed world. In their works, Rabelais and Franz with burning irony denounce the vices of the time that hinder the development of mankind and the prosperity of civilization, express their concerns and ideas about happiness, justice and the future of mankind. And it should be noted that their approaches differ sharply from each other. In the novel "Gargantua and Pantagruel" F. Rabelais expresses his faith in the bright future of mankind, in its prosperity, which can be achieved through light and true science. And in the novel by A. Franz "Penguin Island" there is not a single bright spot, as the writer is deeply skeptical about the progress of mankind, and in his novel represents a wild society worthy of contempt and hatred.

Feeding ecology of a threatened coastal seabird across an inner shelf seascape

Feeding studies provide important information about animals and the environments in which they live. Yet little is known about the diet of the Australian Fairy Tern Sternula nereis nereis, despite the species being listed as threatened (Vulnerable) and in need of research. This study investigated the dietary composition of this bill-loading seabird, at three colony sites of an inner shelf seascape (two marine and one estuarine) using non-invasive digital photography and direct observations (number of observations [n] = 9854). Small surface schooling, inshore spawning fishes were the most important prey at all sites. Blue Sprat Spratelloides robustus, hardyheads (Atherinidae spp.), and garfishes Hyporhamphus spp. dominated the diet, contributing ≥75% of all prey at each site. The abundance of these fishes, whose spawning period overlapped the Fairy Tern breeding season in south-western Australia (October to February), is likely an important factor influencing the location of Fairy Tern colonies. Multivariate statistical analyses showed that dietary composition differed significantly among colony sites, breeding seasons, between courtship and chick feeding, and time of day. Blue Sprat, Beaked Salmon Gonorynchus greyi, and flyingfishes (Exocoetidae spp.) were present in greater proportions at Rottnest Island and Penguin Island (marine sites) than at Point Walter (estuarine). In contrast, hardyheads, Tailor Pomatomus saltatrix, and Yelloweye Mullet Aldrichetta forsteri were more common at Point Walter. Garfishes were around twice as important at Penguin Island than the other sites. Differences in habitat and fish species assemblages at each site may explain the observed spatial trends in dietary composition, while environmental factors, e.g. sea surface temperature and freshwater discharge, and natural interannual variability may explain the observed temporal trends in diet. Fish donated for courtship were ∼21% (12 mm) longer than those provisioned to chicks and the composition of prey in the diet of Fairy Terns differed between courtship and chick feeding at both Point Walter and Penguin Island. Differences in prey handling capabilities and nutritional requirements of adult females and chicks may explain these differences. Dietary composition differed significantly among diurnal periods at Point Walter and Penguin Island, with the greatest differences observed between morning and afternoon periods. At least 30 prey species were recorded, suggesting a degree of feeding opportunism. However, the large proportion of Blue Sprat, particularly at marine colony sites, highlights a potential vulnerability of Fairy Terns to changes in prey availability during their breeding period.

Digital Games in the Elementary Classroom: Using Club Penguin Island with Grade 6 ESL students

L’auteur explore l’interaction négociée chez des élèves de 6e année (âgés de 11 à 12 ans) appelés à effectuer des tâches de communication dans le cadre du jeu de l’Île de Club Penguin, un jeu de rôle en ligne multijoueur de masse. À la différence des chercheurs qui se sont précédemment intéressés aux jeux numériques, il utilise le jeu de l’Île de Club Penguin en contexte d’interaction en classe. L’étude a pour buts d’évaluer la présence d’épisodes mettant l’accent sur la forme (EMAF), d’en définir les caractéristiques, d’évaluer l’incidence de la nature de la tâche et d’analyser les attitudes des participants à la suite de l’utilisation du jeu. Le projet est réalisé auprès de 20 élèves de 6e année inscrits à un programme intensif d’anglais langue seconde (ALS) dans la province de Québec. Une tâche lacunaire, une tâche lacunaire de raisonnement et une tâche comportant un élément de rédaction sont effectuées en dyades à l’aide de tablettes iPads. Des enregistrements et un questionnaire d’attitudes sont utilisés pour colliger les données. L’analyse révèle que les EMAF sont déclenchés au cours de la réalisation des tâches dans le cadre du jeu et que les élèves sont en mesure de négocier l’interaction sans l’aide de leur instructeur. L’auteur constate que la lacunaire entraîne davantage de EMAF et que les attitudes sont positives à l’égard du jeu et des tâches. Les retombées pédagogiques de l’étude font ressortir les conséquences de l’utilisation des jeux de rôle en ligne multijoueur de masse et enrichissent les écrits sur l’interaction négociée des jeunes apprenants.

Magnetic fabric from Quaternary volcanic edifices in the extensional Bransfield Basin: internal structure of Penguin and Bridgeman islands (South Shetlands archipelago, Antarctica)

SUMMARYStudying the magnetic fabric in volcanic edifices, particularly lava flows from recent eruptions, allows us to understand the orientation distribution of the minerals related to the flow direction and properly characterize older and/or eroded flows. In this work, the magnetic fabric from recent (Quaternary) lava flows (slightly inclined in seven sites and plateau lavas in two sites), pyroclastic deposits (two sites from a scoria cone) and volcanic cones, domes and plugs (three sites) from Penguin and Bridgeman islands, located in the Bransfield backarc basin, are presented. The volcanism in the two islands is related to rifting occurring due to the opening of the Bransfield Strait, between the South Shetlands archipelago and the Antarctic Peninsula. The direction of flow of magmatic material is unknown. Rock magnetic analyses, low temperature measurements and electron microscope observations (back-scattered electron imaging and Energy Dispersive X-ray analyses) reveal a Ti-poor magnetite (and maghemite) as the main carrier of the magnetic fabric. Hematite may be present in some samples. Samples from the centre of the lavas reveal a magnetic lineation either parallel or imbricated with respect to the flow plane, whereas in the plateau lavas the magnetic lineation is contained within the subhorizontal plane except in vesicle-rich samples, where imbrication occurs. The magnetic lineation indicates a varied flow direction in Bridgeman Island with respect to the spreading Bransfield Basin axis. The flow direction in the plateau lavas on Penguin Island is deduced from the imbrication of the magnetic fabric in the more vesicular parts, suggesting a SE–NW flow. The volcanic domes are also imbricated with respect to an upward flow, and the bombs show scattered distribution.

Bridgeman Island, Antarctica, ‘burning mount’ or old eroded volcano?

Abstract Deception, Bridgeman and Penguin are the three most recently active volcanic islands in the South Shetland Islands. Since the discovery of the archipelago in 1819, Deception Island has erupted on frequent occasions, most recently in August 1970. A number of nineteenth-century observers reported fumarolic or volcanic activity from Bridgeman Island. No eyewitness accounts of activity from Penguin Island have been found. A chronological list detailing the historic reports from Bridgeman Island was compiled to compare and establish their veracity. This process revealed a consistency of observation from independent observers. An effort has been made to consider if any of these reports of activity may have belonged instead to Penguin Island volcano, 60 km (32 NM) away. A review of the timing of discovery and availability of the first charts of the South Shetlands was also examined to narrow the period when mariners might have mistaken one island for another. Only the three earliest observations of activity from an unnamed volcano, during the short period when no maps were available, may be questioned. A useful chart of the region was published in 1822, and all subsequent observations of activity were from Bridgeman, not Penguin Island.

Ecto- and endoparasites of the King's skink (Egernia kingii) on Penguin Island.

Wildlife species are often host to a diversity of parasites, but our knowledge of their diversity and ecology is extremely limited, especially for reptiles. Little is known about the host-parasite ecology of the Australian lizard, the King's skink (Egernia kingii). In spring of 2015, we carried out a field-based study of a population of King's skinks on Penguin Island (Western Australia). We documented five species of parasites, including two ectoparasitic mites (an undescribed laelapid mite and Mesolaelaps australiensis), an undescribed coccidia species, and two nematode species (Pharyngodon tiliquae and Capillaria sp.). The laelapid mite was the most abundant parasite, infesting 46.9% of the 113 captured lizards. This mite species increased in prevalence and abundance over the course of the study. Infection patterns of both mites varied with lizard life-stage; sub-adults were more commonly infested with laelapid mites than adults or juveniles, and sub-adults and adults were infested by more laelapid mites than juveniles. By contrast, adults had a higher prevalence of M. australiensis than juveniles or sub-adults. Among the gastrointestinal parasites, P. tiliquae was relatively common among the sampled lizards (35.3%). These results give new important information about reptiles as parasite hosts and what factors influence infection patterns.

The diving behaviour of little penguins in Western Australia predisposes them to risk of injury by watercraft

Abstract The most western little penguin colony globally, and the most northern in Western Australia (WA) is found on Penguin Island, WA. The penguins use coastal bays that are also used extensively by recreational watercraft. These penguins have been found to either dive predominantly to shallow depths of 1–5 m or to depths >8 m. It is thus hypothesized that (a) both the shallow and deeper diving penguins can potentially be disturbed or injured by these watercraft but that the risk will differ between the two diving strategies, and (b) that risk of injury for both is greater during the summer and autumn, when people are more likely to use watercraft. This was tested by attaching data loggers to little penguins during chick rearing and by investigating necropsy records. Diving activity was studied for the very shallow and relatively deeper diving penguins separately, and we considered the penguins were vulnerable to interactions with watercraft when they were within the top 2 m of the water column or at the surface. Shallow‐diving penguins executed >1,200 dives per day, 64% of dives occurred within the top 2 m, and they were vulnerable for approximately two‐thirds of their time at sea. The deeper diving penguins executed fewer dives. Almost half of dives were to ≥10 m, yet they were vulnerable for almost one‐third of their time at sea. Their post‐dive recovery was also longer. Thus, the risk of interaction from watercraft differs depending on the diving behaviour. This study highlights the potential impact to little penguins throughout Australia and New Zealand.

Depositional input of hydrocarbons recorded in sedimentary cores from Deception and Penguin Islands (South Shetland Archipelago, Antarctica)

Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs), including petroleum biomarkers, were studied in four sediment cores collected around Deception and Penguin Islands, Antarctica. Total PAHs in Deception Island (DCP) samples ranged from 2.0 to 26.8 ng g−1, and in Penguin Island (PGI) varied between 13.2 and 60.3 ng g−1. Multiple sources of PAHs were verified in DCP, with petrogenic-derived compounds being predominant over the last 10 years. In PGI, PAHs related to natural contributions from the erosion of coal deposits were reported. Total AHs in DCP ranged from 4.5 to 19 μg g−1 and in PGI varied between 5.3 and 21.9 μg g−1. In DCP, the n-alkanes distribution pattern showed the presence of petroleum residues in the top sections and both terpanes and hopanes were detected, related to the use of fossil fuels for power generation and in different types of vessels. In PGI, the main source of n-alkanes was marine inputs and only terpanes were detected. The slight increase in hydrocarbon levels observed from 1980 onward in DCP was assumed to be due to the development of tourism in the region and to the scientific station activities. In PGI, anthropogenic-related hydrocarbons were detected in the recent sections and were linked to the development of tourism near the island, scientific activities and the increase in vessel traffic. In general, the concentrations of hydrocarbons found around both islands were comparable to those found in uncontaminated Antarctic regions.

Significant decline of endangered Antipodes Island penguins: Is extreme weather an additional impact?

Abstract Worldwide, most crested penguin species (Eudyptes spp.) are in decline. New Zealand's subantarctic Antipodes Islands are of international significance for erect‐crested (Eudyptes sclateri) and rockhopper (Eudyptes filholi) penguins. Between 1995 and 2011, a 23% decline was recorded in the two penguin species on the Antipodes Islands. In October 2014, nest abundance counts on Antipodes Island were undertaken to determine if this decline was continuing, particularly in light of a significant storm event that hit the Antipodes area in January 2014 causing massive landslides during the penguin breeding season. All penguin colonies ground counted in 2011 were preferentially ground counted in 2014 or, if time or weather did not allow, were checked with binoculars to confirm colony presence or absence. Seventy‐three per cent of the colonies and the equivalent of 82% of all nests counted in 2011 were recounted in 2014. Overall, there was a 19% decline in erect‐crested penguin nests between 2011 and 2014. Rockhopper penguins showed a slight increase (2.6%). Landslides affected 11% of the main islands’ land area and 44% of surveyed nesting colonies. Erect‐crested penguin colonies with approximately 75% or greater of their area impacted by landslides showed a significantly greater decline than unaffected or only partially impacted colonies. Landslides showed a minimal effect on rockhopper nest numbers. There continues to be a significant decline of erect‐crested penguins at the Antipodes Islands. An increasing occurrence of extreme weather events are predicted with climate change and have the potential to increase land‐based flooding and landslides, adding additional impacts to terrestrial breeding marine species. Greater understanding of what is causing erect‐crested penguin decline is needed to prevent this endangered species from extinction.

Predation of a Buff-banded Rail Hypotaenidia philippensis by Australian Ravens Corvus coronoides on Penguin Island, Western Australia

Australian Ravens Corvus coronoides , although primarily scavengers, are known to prey on large vertebrates, which can detrimentally affect the prey populations. This paper describes an Australian Raven attacking and killing a Buffbanded Rail Hypotaenidia philippensis on Penguin Island, Western Australia, in the presence of several other Ravens.

Pentosidine levels cannot be used to age a long-lived seabird

ABSTRACTRobust measurements of age are important for investigating ecological processes. In particular, seabirds, which form a major part of the coastal and marine ecosystems, may use and respond to their environment differently based on their age. This study aimed to determine whether pentosidine, a biological marker of age which was previously reliably used to age other avian species, could be used to age Bridled Terns (Onychoprion anaethetus) breeding on Penguin Island, Western Australia. It was found that patagial skin collagen-bound pentosidine cannot be used to determine the age of Bridled Terns because of low collagen levels in skin samples and that, overall, there was a low recapture rate of birds born on the island (less than 5% of the birds trapped in this study). Bridled Terns’ diet and life at sea may explain their low skin collagen levels, but some molecular adaptations and antioxidants from their diet may help them resist oxidative challenge. Hence, methods for ageing birds based on collagen content in skin samples may not be uniform across species. Furthermore, low recapture rates in this colony may indicate high levels of dispersal or mortality, which warrant further investigation.

Application of UAV BVLOS remote sensing data for multi-faceted analysis of Antarctic ecosystem

A photogrammetric flight was performed in December 2016 as BVLOS (Beyond Visual Line of Sight) operation over Penguin Island (South Shetland Islands, Western Antarctica). Images were taken by the PW-ZOOM fixed-wing UAV equipped with a digital SLR Canon 700D camera. The flight was performed at 550 m ASL and covered a total distance of 231.58 km. The plane take-off and landing site was near the H. Arctowski Polish Antarctic Station (Arctowski) on King George Island, South Shetlands. The main aim of the mission was to collect environmental data to estimate the size of penguin and pinniped breeding populations and to map vegetation cover and landforms. The plane returned to Arctowski with 1630 images of Penguin Island with the ground sample distance (GSD) lower than 0.07 m. The analysis of developed ortophoto allowed us to locate and identify individuals of two penguin species (Adélie and chinstrap), and individuals of two species of pinnipeds (Southern elephant seal and Weddell seal). Three types of tundra communities were mapped together with numerous landforms such as: volcanic, mass movement, fluvial, coastal and aeolian ones. The UAV BVLOS photogrammetric operation proved to be very robust in gathering valuable qualitative and quantitative data necessary for monitoring distant and isolated polar environments.

Visitor perspectives of risk management in a natural tourism setting: An application of the Theory of Planned Behaviour

Effective management of visitor risk in nature-based tourism and recreation settings requires land managers to have a clear understanding of the perspective of the visitor. The Theory of Planned Behaviour is presented as a valuable analytical framework to better understand visitors’ motivation to voluntarily engage in a behaviour classified by land managers as being risky. Using Penguin Island in Western Australia as a study site, visitors’ reasons for walking across the water-covered sandbar which management had identified as risky were explored. Visitors undertaking this behaviour were interviewed using the theory as a conceptual guide to understand influencing visitors’ decision making process. Results revealed that the activity of walking the sandbar was an experience offering instrumental as well as affective benefits. Subjective norms also influenced visitors’ decision to engage in the behaviour. Even though the decision to perform the behaviour was perceived as a free and deliberate choice, visitors approved management guidance stemming from perceptions of shared responsibility for safety at the site. Our research illustrates that the Theory of Planned Behaviour is a useful tool to identify important insights into individual and situational aspects of visitor behaviour in risky situations. Management implicationsManaging visitor safety in Australian protected areas is a complex interplay between risk and responsibility. Using the Theory of Planned Behaviour as a conceptual framework, the behaviour investigated was disseminated into three distinct elements on which future intervention strategies can be built.•Visitors’ perceived benefits derived from pursuing the risky activity outweighed perceived risks and visitors showed a personal detachment from danger.•Visitors were encouraged to follow others already pursuing the activity, because seeing others led to the belief that it must be safe.•Visitors felt that responsibility for their own safety was shared due to the high presence of management including signs, life guards, and commercial operations.

A rare melanistic chinstrap penguin Pygoscelis antarcticus at Penguin Island, Maritime Antarctica

A eumelanistic chinstrap penguin Pygoscelis antarcticus was registered at Penguin Island, Maritime Antarctica during the 2014/2015 austral summer. Melanism mutations are quite rare for this species, and even though former informal records have been made, as far as we know, this is the first official report of eumelanism in chinstrap penguins.

Impact of the ‘Little Ice Age’ climate cooling on the maar lake ecosystem affected by penguins: A lacustrine sediment record, Penguin Island, West Antarctica

A Pliocene-age volcano on Penguin Island became active again in the Pleistocene/Holocene, forming the main cone of the island – Deacon Peak, and leaving late-Holocene phreatomagmatic craters, including ‘Petrel Crater’, about 200 m in diameter and filled currently by a maar lake with a flat bottom at 18 m water depth. Petrographic, geochemical, photosynthetic pigment, and diatom data from the 72-cm-long sediment core reveal that the crater was initially a marine lagoon with typical phytoplankton assemblages. Most probably, tectonic–volcanic activity about 1250 years ago, documented in tephra fallout, triggered an abrupt glacio-isostatic uplift that separated the lake from the sea. The horizon of tephra, probably from the Deception Island volcano, marks a sudden change in environment from brackish to lacustrine. The ecological evolution of the lake was initially constrained by an uplift, whereas the influence of marine water vanished with time, the lake became meromictic, and the freshwater mixolimnion layer expanded, while the monimolimnion became anoxic due to the influence of a penguin rookery situated on the shore. During the ‘Little Ice Age’ (LIA), the maar may have been covered by permanent ice. A discharge of mineralized guano from the possibly enlarged penguin rookery on the lake shore caused an expansion of the anoxic monimolimnion to the ice surface and an important reduction of autochthonous lacustrine biota of the maar, whereas a substantially increased participation of allochthonous biota passively supplied with guano. That record in the lake sediment core reaffirms the occurrence of a regional LIA event in the maritime Antarctic.

Depositional history of sedimentary sterols around Penguin Island, Antarctica

AbstractLipid biomarkers are potential tools for identifying the sources, diagenesis and reactivity of organic matter (OM) in marine systems, including in Antarctica where the particular environmental characteristics have motivated several studies of organic markers. Sedimentary sterol distributions were determined in two sediment cores (PGI-1 and PGI-2) collected from the marine environment around Penguin Island, Antarctica, during the 2007–08 summer. The cores were sectioned at 1 cm intervals and the sterols were analysed using gas chromatography with flame ionization detection. The results indicate that the sterols were subjected to decades of degradation and transformation with depth in both cores. However, an expected progressive conversion of stenols to stanols (evaluated by 5α-stanols/Δ5-stenols ratio) within the deepest sediment layers was not clear, suggesting low degradation rates. In PGI-1, the deposition of large quantities of penguin guano affected the distribution of sterols and, consequently, primary production was favoured by the ornithogenic soil input. The results contribute to the understanding of the current processes associated with primary sources and transformation of OM in this important region of the Antarctic environment.

Anthropogenic and biogenic hydrocarbons in soils and vegetation from the South Shetland Islands (Antarctica)

Two Antarctic expeditions (in 2009 and 2011) were carried out to assess the local and remote anthropogenic sources of aliphatic and aromatic hydrocarbons, as well as potential biogenic hydrocarbons. Polycyclic aromatic hydrocarbons (PAHs), n-alkanes, biomarkers such as phytane (Ph) and pristane (Pr), and the aliphatic unresolved complex mixture (UCM), were analysed in soil and vegetation samples collected at Deception, Livingston, Barrientos and Penguin Islands (South Shetland Islands, Antarctica). Overall, the patterns of n-alkanes in lichens, mosses and grass were dominated by odd-over-even carbon number alkanes. Mosses and vascular plants showed high abundances of n-C21 to n-C35, while lichens also showed high abundances of n-C17 and n-C19. The lipid content was an important factor controlling the concentrations of n-alkanes in Antarctic vegetation (r2=0.28–0.53, p-level<0.05). n-C12 to n-C35 n-alkanes were analysed in soils with a predominance of odd C number n-alkanes (n-C25, n-C27, n-C29, and n-C31), especially in the background soils not influenced by anthropogenic sources. The large values for the carbon predominance index (CPI) and the correlations between odd alkanes and some PAHs suggest the potential biogenic sources of these hydrocarbons in Antarctica. Unresolved complex mixture and CPI values ~1 detected at soils collected at intertidal areas and within the perimeter of Juan Carlos research station, further supported the evidence that even a small settlement (20 persons during the austral summer) can affect the loading of aliphatic and aromatic hydrocarbons in nearby soils. Nevertheless, the assessment of Pr/n-C17 and Ph/n-C18 ratios showed that hydrocarbon degradation is occurring in these soils.