During the 2007–08 Spanish Antarctic campaign, two moorings of bottom pressure sensors were carried out over a ten week period. This paper presents the results of the tidal analysis from sea level records obtained at Deception and Livingston islands (South Shetland Islands, Antarctica). The main objective of this paper is to present a detailed study of the tidal characteristics at these two islands, for which statistical and harmonic analysis techniques are applied to the tidal records. A geodetic network was used to reference the pressure sensors. Geometric levelling, with an accuracy of 1 mm, allowed us to link the tidal marks with geodetic vertices located on Livingston and Deception islands. The amplitudes and phase lags obtained by harmonic analysis are compared to the harmonic constants of several coastal stations and co-tidal and co-range charts. Results show an evident influence of tides in the sea level signal, with a clear mixed semi-diurnal behaviour and a daily inequality between high and low waters. Measurements of salinity and temperature were made using electronic sensors. Results from this study showed that salinity and temperature were strongly influenced by tides. Seawater temperature varied in a manner that was consistent with the time series of residual bottom pressure.

Earth-orbiting satellites can now monitor calving of large icebergs from ice shelves bordering the marine West Antarctic Ice Sheet, and recent calving events have stimulated interest in calving mechanisms. To advance this interest pioneering work in brittle and ductile fracture mechanics is reviewed, leading to a new application to calving of giant icebergs from Antarctic ice shelves. The aim is to view iceberg calving as more than terminal events for Antarctic ice when glaciologists lose interest. Instead calving launches Antarctic ice into the larger dynamic system of Earth's climate machine. This encourages a holistic approach to glaciology.

Six new species of marine Enchytraeidae, Grania hirsuticauda sp.n., G. acanthochaeta sp.n., G. carchinii sp.n., G. angustinasus sp.n., G. antarctica sp.n. and G. algida sp.n., are described from benthic material collected in McMurdo Sound during 1959–61 and Terra Nova Bay in 1988. They represent the first records of this family from below the Antarctic circle and, together with tubificids, the first oligochaetes from the Ross Sea. G. hirsuticauda, apparently the most widespread species in McMurdo Sound, is distinguished by having setae abruptly larger in the posterior third of the body and almost nodulate; a T-shaped prostomial bifurcation of the dorsal vessel, short sperm funnels and sperm sac, and thick-walled spermathecae. G. acanthochaeta possesses a unique, thorn-like, setal morphology and diverticulate spermathecal ampullae. G. carchinii, the only new species lacking lateral setae, is also distinguished by a remarkably high development of the chloragogen tissue and the possession of nephridia at 6/7. G. angustinasus, the most abundant species in the sampling area in Terra Nova Bay, and G. antarctica, have the same setal distribution, size and (curved) shape, but show different forms of penial bulbs (more complex in G. angustinasus) and spermathecal structures (the ampullae being larger and the external pores more posterior in G. antarctica). G. algida is distinguished by its L-shaped setae and carrot-shaped, diverticulate, spermathecal ampullae. All the new species lack cuticular penial stylets as well as spermathecal ectal glands. All species but G. carchinii are peculiar in possessing, in front of the brain, a middorsal vesicular body of specific shape and size containing a few refractile inclusions; a sensory (possibly a statocyst-like) function is suggested for this ‘head organ’, which has not been previously reported in the Oligochaeta.

Since the Last Glacial Maximum, ice has retreated through the fjords of the South Shetland Islands leaving a valuable record of submarine landforms behind. In this study, glacial landforms and sub-bottom characteristics have been mapped to investigate the late Holocene retreat behaviour of the Fourcade Glacier and to delineate past environmental processes in Potter Cove, King George Island. The comprehensive datasets include high-resolution swath bathymetry, shallow seismic profiling and one sediment core. Moraines, moraine incisions and glacial lineations were mapped on the sea floor in the inner part of the cove, whereas pockmarks, ice scour marks and channel structures were identified in the outer part. Sub-bottom characteristics have been assigned to different acoustic facies types indicating different depositional settings. The results reveal glacial recessions as well as stillstands and potential readvances during the late Holocene. Furthermore, the sediment record indicates that the Fourcade Glacier was situated inside the inner cove during the Little Ice Age (500–100 cal yr bp).

A collection of juvenile squid were caught with the Isaacs-Kidd midwater trawl (IKMT) and the Juday plankton net at 86 stations in Prydz Bay (60°–67°30′S, 60°–80°E) to a depth of 500 m but mostly at 0–200 m. Five species were identified, Psychroteuthis glacialis, Alluroteuthis antarcticus, Brachioteuthis sp. and the cranchiids Galiteuthis glacialis and Mesonychoteuthis hamiltoni. P. glacialis and the cranchiids were the most abundant species. Young P. glacialis (5–17 mm ML) were taken at depths of 5–200 m but concentrated in the upper 100 m whilst the cranchiids (5–35 mm ML) occurred over a wider vertical range (50–500 m). The regular occurrence of paralarvae and juveniles suggests that all the species reproduce in the Antarctic. Juvenile Vertical distribution appears to differ between species with P. glacialis concentrated relatively near the surface, the cranchiids in the upper part of the Circumpolar Deep Water and A. antarcticus widely distributed to a depth of 900 m.

A summer study of the vertical structure of bi-layered microbial mats was carried out on Byers Peninsula (Livingston Island, South Shetland Islands). These benthic communities had a common basic structure that consisted of two distinct layers differing in composition, morphology and colour. Our sampling focused on mats showing more layering, which thrived over moist soils and at the bottom of ponds. The photosynthetic pigments analysis performed by high-performance liquid chromatography demonstrated a major occurrence of cyanobacteria and diatoms on these mats, the former being more abundant in relative terms on the surface and composed by morphospecies grouping into orders Oscillatoriales, Nostocales and Chroococcales. The areal chlorophyll a concentrations were slightly higher in the deeper layer although not significantly. Our microscopic and chemical analyses showed that non-active biomass accumulates at the surface. Hence, the upper layers showed the sheath pigment scytonemin and higher amounts of exopolysaccharides, as a strategy to cope with environmental stress. On the other hand, the basal layer was composed of more active photosynthetic microbiota, which also revealed a more balanced stoichiometry. Here we exemplify how environmental stresses are potentially overcome by physiological mechanisms developed by microbial mats which also shape their vertical structure.

The geographical distribution of protozoan parasite Cephaloidophora pacifica Avdeev (Order Eugregarininda) associated with Antarctic krill, Euphausia superba, was examined in samples collected from the vicinity of the Antarctic Peninsula, near Syowa Station, and Pacific and Indian sectors of the Southern Ocean. Cephaloidophora pacifica was found at all stations around the Antarctic, with 96.4% of the euphausiids infected (n = 195). The numbers of C. pacifica per krill ranged from 0 to 8089 krill-1, and the average was 350.0 ± 787.8 (mean ± SD). The frequency distributions of C. pacifica showed an overdispersed parasite population (i.e. the variance was greater than the mean) at all locations. Statistical analysis showed that whilst the geographical location did not have a significant effect on intensity of C. pacifica the maturity stage of krill did, with an increasing intensity of infection as krill matures. The infestation of E. superba by eugregarinid protozoan is considered to be a circum-Antarctic phenomenon, and it occurs equally throughout the Southern Ocean.

The study describes the annual cycle of southern elephant seals for the increasing colony of Península Valdés, and compares it to the haul-out pattern reported for stable or decreasing sub-Antarctic colonies of the species. Data were collected during censuses of the entire colony (nine breeding seasons, two moulting seasons and one autumn–winter haul-out), monthly surveys of coastline and mark-recapture of pups. Pup production during the study period grew from 12 113 to 14 621 animals (1995–2003). Most relevant events of the cycle were similar for all colonies studied, independent of the geographical location, size or population trend. Compared with other locations where southern elephant seals breed and moult, distinct features for Península Valdés were: i) breeding occurs earlier in the spring, and ii) most adult females reproduce and moult in the same colony. The increasing number of animals ashore was correlated with the expansion in pup production. Population trends and stability of demographic events could be related to a consistent physical environment (ocean fronts) during foraging phases of the annual cycle.

We report the breeding success of four species of burrow-nesting petrels at sub-Antarctic Marion Island where house mice Mus musculus are the sole introduced mammal. Feral cats Felis catus were present on Marion for four decades from 1949, killing millions of seabirds and greatly reducing petrel populations. Cats were eradicated by 1991, but petrel populations have shown only marginal recoveries. We hypothesize that mice are suppressing their recovery through depredation of petrel eggs and chicks. Breeding success for winter breeders (grey petrels Procellaria cinerea (34±21%) and great-winged petrels Pterodroma macroptera (52±7%)) were lower than for summer breeders (blue petrels Halobaena caerulea (61±6%) and white-chinned petrels Procellaria aequinoctialis (59±6%)) and among winter breeders most chick fatalities were of small chicks up to 14 days old. We assessed the extent of mouse predation by monitoring the inside of 55 burrow chambers with video surveillance cameras (4024 film days from 2012–16) and recorded fatal attacks on grey (3/18 nests filmed, 17%) and great-winged petrel chicks (1/19, 5%). Our results show that burrow-nesting petrels are at risk from mouse predation, providing further motivation for the eradication of mice from Marion Island.

The management of sediment and water contamination from legacy waste is a significant problem in Antarctica. Although several reports have noted that there are contaminated sites at the abandoned Wilkes Station, a systematic attempt to assess the spatial scale of the problem has not been made, making development of clean-up or preservation programmes difficult. A contaminated site assessment for the old Wilkes Station and surrounds is presented in this paper. The Australian and New Zealand Environment and Conservation Council (ANZECC) sediment and water quality guidelines and background concentration levels (BCL) were used to assess the extent of contamination across Clark Peninsula. Of 67 sediment sites sampled, 72% were contaminated with at least one metal or metalloid, with values exceeding the ANZECC ISQG-High or 2 x BCL. Moreover, 19% were contaminated with four or more metals/metalloids. Of the 93 water samples collected, all but one was contaminated with at least one metal/metalloid concentration exceeding the guidelines, and 96% were contaminated with two or more metals/metalloids. For hydrocarbons in sediment and water, most samples were below quantitation limits. There is a complex pattern of contamination across Clark Peninsula that needs to be considered in future waste treatment, containment or removal operations, and for protection of heritage items.

The majority of species of the Antarctic coastal fish fauna is represented today by the perciform suborder Notothenioidei. The separation of basal lineages of notothenioids has been estimated to have occurred between 23 and 22 million years ago (m.y.a.), while a major diversification probably occurred 16–10 m.y.a. Cytogenetic approaches aim to study the genomic change that, at the cell level, accompanied the radiation of this group. The information available for 66 of 120–130 species makes possible the description of the main patterns of chromosome diversification within the suborder. Within some families (Channichthyidae, Artedidraconidae) the range of the chromosomal variability seems to be minimal whilst the high karyotypic diversity of Nototheniidae and Bathydraconidae is consistent with morphological and molecular data suggesting the paraphyletic nature of these two taxa. Molecular cytogenetics allows detailed chromosome characterization, including mapping of ribosomal genes and of telomeric sequences, thus providing information on processes of karyotypic rearrangement and direction of chromosomal change. Active process of genomic restructuring leads to intraspecific variability in several species, at different levels of chromosomal organization. The growing amount of information make it possible to use notothenioids as a model for testing hypotheses of evolutionary change in marine organisms, including chromosomal diversification.

The VLNDEF (Victoria Land Network for DEFormation control) project started in 1999 with the aim of detecting crustal deformation in Northern Victoria Land (Antarctica) over an area that had never been surveyed by a dense GPS network before. After a brief summary of the Italian geodetic activities carried out since 1991, the paper presents the results obtained from the processing of data collected from 1999 to 2003. In particular, processing strategies were dealt with, in order to produce horizontal and vertical displacement maps through GPS observations. Absolute motions in a global reference frame have been investigated using a double approach, which allowed us to make considerable progress in detecting movements and standardizing the data analysis. The analyses provide absolute horizontal velocities ranging between 17 mm yr−1 and 8 mm yr−1, with greater motions in the northernmost area. The subtraction of the rigid plate motion provides relative displacements, which may contribute to the understanding of neotectonics and geology, whereas the pattern of the vertical crustal motions detected, with average values of +1.3 mm yr−1, is essential to detect the effect of Glacial Isostatic Adjustment (GIA) and other geophysical signals, and to redefine theory and numerical models used without any direct measurements.

Mineral soils in the McMurdo Dry Valleys (MDV), Antarctica, are commonly considered to be dry, and therefore to be good insulators with low thermal diffusivity values (~0.2 mm2 s-1). However, field measurements of soil moisture profiles with depth, coupled with observations of rapid ground ice melt, suggest that the thermal characteristics of MDV soils, and thus their resistance to thaw, may be spatially variable and strongly controlled by soil moisture content. The thermal conductivity, heat capacity and thermal diffusivity of 17 MDV soils were measured over a range of soil moisture conditions from dry to saturated. We found that thermal diffusivity varied by a factor of eight for these soils, despite the fact that they consist of members of only two soil groups. The thermal diffusivity of the soils increased in all cases with increasing soil moisture content, suggesting that permafrost and ground ice thaw in mineral soils may generate a positive thawing feedback in which wet soils conduct additional heat to depth, enhancing rates of permafrost thaw and thermokarst formation.

An ecological study of the soil testate amoebae (Protozoa, Rhizopoda) communities on the sub-Antarctic island of Île de la Possession (Îles Crozet) revealed 65 taxa, belonging to 20 genera. Trinema lineare and Euglypha laevis were the most dominant species in all types of soils on the island. A Redundancy Analysis revealed three communities that characterize specific habitats: i. fellfield soils, characterized by low moisture values and low organic material content, contained fewer taxa and fewer individuals, ii. peaty valley soils, with lower pH values, showed high abundances and diversity, and iii. soils influenced by sea spray and marine animals had higher nutrient contents, elevated chloride and conductance values, resulting in more tests of Difflugiella oviformis, Nebela dentistoma and Edaphonobiotus campascoides. Special attention was given to the species composition in relation to the soil type and its moisture content. A comparison with aquatic habitats on Île de la Possession was made.

Astronomers have always sought the very best locations for their telescopes. From observatories in city centres, astronomers moved first to nearby mountain tops, then to remote sites in distant countries, to aircraft, and into space. In the past decade we have come to realize that the best astronomical observing conditions on the surface of the earth are to be found on the Antarctic plateau. The combination of high altitude, low temperature, low absolute humidity, low wind and extremely stable atmosphere offers astronomers gains in sensitivity and measurement precision that can exceed two orders of magnitude over even the best temperate sites. In addition, spectral windows are opened up – particularly in the far-infrared and terahertz regions – that are otherwise only accessible from high-flying aircraft or from space. Established and highly successful telescopes at the South Pole are soon to be joined by a new generation of facilities at Concordia Station, including large telescopes and interferometers. It has even been suggested that the largest optical telescopes currently proposed, with diameters of up to 100 m, might achieve their science goals at a lower overall cost if they are built on the Antarctic plateau rather than at a temperate site. Such telescopes offer the possibility of not only detecting earth-like planets in other star systems, but also of analysing their atmospheres spectroscopically.

The relationship between colony area and population density of Adélie penguins Pygoscelis adeliae was examined to determine whether colony area, measured from aerial or satellite imagery, could be used to estimate population density, and hence detect changes in populations over time. Using maps drawn from vertical aerial photographs of Adélie penguin colonies in the Mawson region, pair density ranged between 0.1 and 3.1 pairs m−2, with a mean of 0.63 ± 0.3 pairs m−2. Colony area explained 96.4% of the variance in colony populations (range 90.4–99.6%) for 979 colonies at Mawson. Mean densities were not significantly different among the 19 islands in the region, but significant differences in mean pair density were observed among colonies in Mawson, Whitney Point (Casey, East Antarctica) and Cape Crozier (Ross Sea) populations. The relationship between colony area and population may be locality-and/or species-specific, and a robust data set is required to validate the relationship.

The depositional environment of the Devonian Taylor Group has been subject to considerable debate for over 30 years. The debate stems largely from a belief that the abundant and diverse trace fossils represent a marine ichnofauna, whereas sedimentary features, including palaeosols, desiccation polygons and red beds, are more typical of a non-marine setting. The debate is reconciled by a reinterpretation of the trace fossil assemblage which shows that the trace fossils comprise a typical fresh water (Scoyenia ichnofacies) assemblage, and their occurrence in the Taylor Group in the Darwin Glacier area is entirely consistent with deposition in a mixed fluvial-lacustrine-subaerial environment.

Perinatal specimens give valuable information about the first stages of vertebrate ontogeny. Here, the morphology and palaeohistology of an aristonectine perinatal specimen from Seymour Island (Isla Marambio), López de Bertodano Formation are analysed. The palaeohistological analysis shows incomplete endochondral ossification (retention of a calcified cartilaginous core in the medullary region), predominance of primary bone tissue without secondary remodelling, lack of primary or secondary osteons and of growth marks in the cortical bone, and open vascular spaces not surrounded by a thin coat of lamellar bone tissue. General lines of morphological changes were inferred from comparing the fossil with an adult aristonectine specimen indicating i) a tendency of relatively high and broad posterior cervicals to decrease during ontogeny, ii) a decrease of relative size of the dorsolateral process and an increase of the glenoid ramus and iii) the existence of two separate stages in propodial growth divided into an initial elongation followed by a distal expansion. The presence of a perinatal specimen in the James Ross Archipelago indicates that the region was used as a breeding area by the aristonectines during the last part of the Cretaceous.

Bioaugmentation is a controversial strategy. In this work, the effect of the inoculum size and the absence of natural microflora on the efficiency of hydrocarbon removal were studied. Two levels of inoculum (106 and 109 CFU g-1) were applied to soil microcosms containing sterile (S6 and S9) and non-sterile (NS6 and NS9) oil contaminated Antarctic soil. Community controls (CC) and biostimulated autochthonous microflora (BAM) were also included. Total heterotrophic aerobic (THAB) and hydrocarbon degrading (HDB) bacteria as well as total petroleum hydrocarbons (TPH) were analysed. At day 0, THAB and HDB counts (CFU g-1) showed no differences among CC, BAM and NS6 but significantly higher values were observed in NS9 and S9. At day 60, three different levels of HDB were observed. The lower level was represented by CC (106 CFU g-1), a second group (5 x 107 CFU g-1) was represented by BAM, NS6, NS9 and S6, and the third level was constituted by S9 (1 x 109 CFU g-1). TPH values at day 60 decreased significantly in all systems excluding the controls. NS6, NS9, S6 and S9 were not different from those corresponding to BAM. Results suggest that the bioaugmentation of a chronically diesel fuel-contaminated Antarctic soil is unlikely to be profitable or beneficial.