The net photosynthetic rate (NP), chlorophyll fluorescence, carotenoid content and chlorophyll content of the cosmopolitan moss Bryum argenteum were measured in the field at Botany Bay, southern Victoria Land, continental Antarctica (77°S). Comparisons were made between sun- and shade-adapted forms, and changes were followed as the moss emerged from under the snow and during exposure of shade and sun forms to ambient light. Shade forms had lower light compensation and saturation values for NP but little difference in maximal NP rates. Shade forms exposed to ambient light changed rapidly (within five days) towards the performance of the sun forms. Surprisingly, this change was not by acclimation of shoots but by the production of new shoots. Chlorophyll and carotenoid levels measured on a molar chlorophyll basis showed no difference between sun and shade forms and also little change during emergence. The constant molar relationship between carotenoids and chlorophyll plus the high levels of the xanthophyll cycle pigments suggest that protection of the chlorophyll antenna was constitutive. This is an adaptation to the very high light levels that occur when the plants are active in continental Antarctica and contrasts to the situation in more temperate areas where high light is normally avoided by desiccation.

Livingston Island contains several, distinctive sedimentary and volcanic sequences, which document the history and evolution of an important part of the South Shetland Islands magmatic arc. The turbiditic, late Palaeozoic–early Mesozoic Miers Bluff Formation (MBF) is divided into the Johnsons Dock and Napier Peak members, which may represent sedimentation in upper and lower mid-fan settings, respectively, prior to pre-late Jurassic polyphase deformation (dominated by open folding). The Moores Peak breccias are formed largely of coarse clasts reworked from the MBF. The breccias may be part of the MBF, a separate unit, or part of the Mount Bowles Formation. The structural position is similar to the terrigenous Lower Jurassic Botany Bay Group in the northern Antarctic Peninsula, but the precise stratigraphical relationships and age are unknown. The (?) Cretaceous Mount Bowles Formation is largely volcanic. Detritus in the volcaniclastic rocks was formed mainly during phreatomagmatic eruptions and redeposited by debris flows (lahars), whereas rare sandstone interbeds are arkosic and reflect a local provenance rooted in the MBF. The Pleistocene–Recent Inott Point Formation is dominated by multiple, basaltic tuff cone relicts in which distinctive vent and flank sequences are recognized. The geographical distribution of the Edinburgh Hill Formation is closely associated with faults, which may have been reactivated as dip-slip structures during Late Cenozoic extension (arc splitting).

Two mitochondrial DNA regions and seven microsatellite loci were examined in Patagonian toothfish from three locations in the Southern Ocean (Macquarie Island, five collections; Heard and McDonald Islands, four collections; Shag Rocks/South Georgia area, one collection). Striking mtDNA heterogeneity was detected between the three fishing locations (FST=0.445, P<0.001), but spatial and temporal collections within the same location were not significantly different. No significant overall microsatellite differentiation between the three locations was apparent (FST=−0.009, P=0.785). However, some individual loci showed small but significant differentiation, which in each case was attributable to between rather than within-location differentiation. Greater differentiation of mtDNA can, in principle, be explained either by female philopatry and male dispersal, or by its greater sensitivity to changes in effective population size. The latter seems more likely as tagging indicates that toothfish is generally a sedentary species. The genetic heterogeneity between the three locations indicates restricted gene flow, with the fish at each location comprising independent units. Depletion in one location is therefore unlikely to be quickly replaced by immigration from another.

Soil CO2 emission is an important part of the terrestrial carbon cycling and is influenced by several factors, such as type and distribution of vegetation. In this work we evaluated the spatial variability of soil CO2 emission in terrestrial ecosystems of maritime Antarctica, under two contrasting vegetation covers: 1) grass areas of Deschampsia antarctica Desv., and 2) moss carpets of Sanionia uncinata (Hedw.) Loeske. Highest mean emission was obtained for the Deschampsia (4.13 μmol m-2 s-1) developed on organic-rich soil with a strong penguin influence. The overall results indicate that soil temperature is not directly related to the spatial pattern of soil CO2 emission at the sites studied. Emission adjusted models were Gaussian and exponential with ranges varying from 1.3 to 2.8 m, depending on the studied site and vegetation cover.

It appears that squid statoliths cannot yet be regarded as accurate an ageing tool as fish otoliths. Statoliths from the same pair, prepared differently for viewing and counting increments, were compared. Increment counts do not imply age in days, because this was not validated. One statolith from each pair was examined by light microscopy (LM) after preparation following a new method. The other was viewed by Scanning Electron microscopy (SEM) with a modified etching solution. Shape of each statolith was similar when compared by multiple regression analysis (11 variables, n=53). There was a weak but significant difference between sexes (statoliths of females were slightly larger). All other differences were insignificant. Microscopic observation and increment counts of increments were successfully carried out for 37 pairs of statoliths. Significant differences between two independent counts were found for the LM method, but no significant differences were found between two independent SEM counts. Counts were significantly different when interpreted by both LM and SEM, probably because of poor resolution in the LM readings and over-resolution (growth layers prominent and numerous) in those read by SEM. Recommendations are made on how ageing studies, based on statoliths, should be structured and the results evaluated.

We present direct terrestrial evidence of ice volume change of the Darwin and Hatherton glaciers which channel ice from the Transantarctic Mountains into the Ross Ice Shelf. Combining glacial geomorphology with cosmogenic exposure ages from 25 erratics indicates a pre-LGM ice volume at least 600 m thicker than current Hatherton ice elevation was established at least 2.2 million years ago. In particular, five erratics spread across a drift deposit at intermediate elevations located below a prominent moraine feature mapped previously as demarcating the LGM ice advance limits, give a well-constrained single population with mean 10Be age of 37.0 ± 5.5 ka (1σ). At lower elevations of 50–100 m above the surface of Lake Wellman, a further five samples from within a younger drift deposit range in exposure age from 1 to 19 ka. Our preferred age model interpretation, which is partly dependent on the selection of a minimum or maximum age-elevation model, suggests that LGM ice volume was not as large as previously estimated and constrains LGM ice elevation to be within ± 50 m of the modern Hatherton Glacier ice surface, effectively little different from what is observed today.

Penguin blood samples collected at Bird Island, sub-Antarctic South Georgia, and faecal samples taken from penguins at several localities along the Antarctic Peninsula were analysed in order to investigate if influenza A virus is present in penguin populations in the South Atlantic Antarctic region. Serology was performed on the blood samples while the faecal samples were screened by a RT-PCR method directed at the matrix protein gene for determining the presence of influenza A virus. All faecal samples were negative by PCR, but the blood samples gave serologic indications that influenza A virus is present amongst these penguin species, confirming previous studies, although the virus has still not been isolated from any bird in the Antarctic region.

Archaean gneisses in the Rauer Group of islands, East Antarctica, record a prolonged history of high-grade deformational episodes, many of which predate that identified in mid-Proterozoic gneisses. Eleven generations of mafic dykes, belonging to discrete chemical suites, have been used as relative time markers to constrain this deformational history. Based on the timing of intrusion with respect to structures, dykes in the Rauer Group have been correlated with largely undeformed and dated dyke suites in the adjacent Vestfold Hills. This has allowed absolute ages to be inferred for the early- to mid-Proterozoic mafic dyke suites in the Rauer Group, and a correlation of the interspersed structural events. Most structures in the Rauer Group, however, developed in response to high-grade progressive deformation at approximately 1000 Ma. During this deformational episode, strains were repeatedly partitioned into sub-vertical, noncoaxial, high-strain zones recording NW-directed sinistral transpression, that separated zones of lower strain dominated by coaxial folding with axes parallel to the shear direction. Three additional mafic dyke suites intruded during this deformation which was followed by three stages of brittle-ductile deformation and a final suite of lamprophyre dykes. Due to the numerous intrusive time markers, the Rauer Group serves as an excellent illustration of how complicated gneiss terrains may be.

A short summary of some the most important hypotheses on the evolution of Southern Ocean peracarid crustaceans and some of the potential reasons for the high biodiversity of this taxon is presented. Besides the knowledge of horizontal and vertical distribution patterns of Southern Ocean peracarids, the importance of the evolution of the notothenioid fishes on the evolution of the Peracarida is discussed. Key questions for a better understanding of evolutionary biology of Southern Ocean Peracarida are highlighted.

The ice surface of the glacier in the 7 km long valley Scharffenbergbotnen in Heimefrontfjella, Dronning Maud Land, is characterized by blue ice fields and is partly covered by supraglacial moraine complexes. The debris cover of the supraglacial moraines is generally less than 50 cm thick and rests on glacial ice, and most of the surface morphology of ridges and numerous sink holes reflects irregularities in the underlying ice. The debris consists of angular to sub-angular clasts of local bedrock. We interpret the moraines to have an entirely supraglacial history, where colluvium and pre-existing moraines were brought into Scharffenbergbotnen primarily from the south/south-west by an advancing glacier during the last ice maximum in the region. The debris cover of the supraglacial moraines extends up to 200–250 m above the present ice surface on surrounding slopes in Scharffenbergbotnen, and generally to less than 100 m above the present ice surface on slopes outside the valley. We interpret this as marking the ice surface elevation in the area during the last ice maximum (probably LGM). The deposition of supraglacial moraines in the valley at that time, and their survival in the area until the present day, indicate that a local ablation centre and probably blue ice fields were present in Scharffenbergbotnen at LGM, and has been a persistent feature since. In a wider context, we argue that supraglacial moraines constitute a hitherto unexploited resource when reconstructing the former extent of blue ice areas.

The structure and variability of Southern Ocean fronts south of New Zealand are described based on fifteen summer expendable bathythermograph (XBT) sections obtained between 1994 and 2001. The temperature variability north of 60°S is dominated by meanders and meridional shifts of the Sub-Antarctic Front (SAF), which often bifurcates to form northern and southern branches. The northern branch follows the southern edge of the Campbell Plateau, while the southern branch is found over the abyssal plain of the south-west Pacific Basin. The northern and southern branches of the SAF can be separated by as much as 900 km. Intense eddies or meanders of the SAF displace isotherms by as much as 5 degrees of latitude from their positions when such features are absent. The Polar Front (PF) position is more stable in time, although cold-core features associated with eddies or meanders of the front are occasionally observed between the southern SAF and the PF. The position of the southern ACC front is extremely stable, consistently overlying the 3000 m isobath on the northern flank of the Pacific-Antarctic/south-east Indian Ridge.

This paper presents the results of the analysis of hydrological data of a 5-day mesoscale experiment (53 CTD casts) conducted during the XIIIth Italian Expedition to Antarctica (1997–98 cruise) in the framework of the CLIMA (Climatic Longterm Interaction for the Mass balance in Antarctica) Project of the Italian National Programme for Antarctic Research (PNRA). The experiment site was chosen for studying the dense water overflow in relation to the shelf-break in the central Ross Sea, after a large-scale synoptic survey, aimed to detect the general hydrological characteristics of the basin. A classical θ/S analysis was carried out for better understanding of the shelf-slope connection and the interactions between the water masses of this zone: the Circumpolar Deep Water (CDW) coming from the oceanic domain and the Ice Shelf Water (ISW) spreading from the Ross Ice Shelf (RIS) edge. Our results show the evidence of an overflow of dense water, originated on the continental shelf, on the shelf-break. This supercold water signal is found on the continental slope down to 1200 m depth. The shape of this tongue of modified ISW, whose thickness reaches up to 100 m, is very narrow, suggesting that the overflow occurs in very localized areas.

Small to medium sized icebergs (200 m to 10 km across) in two areas of the Weddell Sea were tracked using satellite-borne Synthetic Aperture Radar (SAR) from 22 January–21 February 1994 and 29 January–25 February 1992 respectively. The westward mass flux of icebergs in the Antarctic Coastal Current was estimated at the eastern entrance to the Weddell Sea as being 50–70 Gta−1. A large contrast was found between observations over the narrow shelf here and the off-shelf area. The latter region had very much reduced iceberg density, and the bergs moved with slower and less coherent velocities compared with the fast, but narrow (10–20 km wide) flow in the Coastal Current. This region is a promising site for the monitoring of decadal trends in iceberg fluxes. The second study area in the south-western Weddell Sea showed iceberg motion consistent with non-contemporaneous observations of tagged icebergs, with steady flow parallel to the shelf-ice edge, at significantly lower densities and speeds than in the Coastal Current but almost double that observed off-shelf in the eastern Weddell Sea. We also suggest that shipboard observations of icebergs need careful analysis to avoid their over-estimating true iceberg concentrations by a substantial amount.

Nematodes of the families Heterorhabditidae and Steinernematidae are obligate parasites of a wide range of insects (Poinar 1979). The third stage juvenile of these nematodes is a non-feeding infective form which carries symbiotic insect-pathogenic bacteria (Xenorhabdus spp.) in its intestine. Under favourable conditions the juveniles can survive for months in the soil. They are attracted to and enter insects. After invading the haemocoel they release the symbiont. The bacteria multiply, kill the host by septicaemia, and provide suitable conditions for nematode growth and reproduction. After one to two weeks, the newly formed infective juveniles leave the cadaver and seek new hosts.

In this review we consider the physical processes that shape inland aquatic ecosystems and how these affect ecosystem processes, with particular focus on the nitrogen cycle. Inland Antarctica is dominated by microbial communities that are usually concentrated in, or adjacent to, habitats with free water. The presence of free vs frozen water is dependent on very small changes in temperature around 0°C, so significant variability in the distribution of free water can be expected in response to variations in climate over diel, decadal, to millennial time scales and a range of spatial scales. Antarctic inland waters take many forms: snow-surface melt pockets, cryoconites, basal regions of wet-based glaciers, ponds (varying in salinity and degree of desiccation), melt streams, perennially and seasonally ice covered lakes and even hypersaline, ice free lakes. The important processes and transformations that characterize the nitrogen cycle worldwide have all been identified in Antarctic inland waters and in some cases (e.g. N-uptake, N-fixation), rates are similar to those at lower latitudes. The unique features of Antarctic ecosystems stem from the extreme and variable physical conditions under which these processes operate rather than any unique ecosystem processes per se.

The distribution and abundance of free-living arthropods from soil and under stones were surveyed at the Cape Hallett ice-free area (ASPA No. 106), North Victoria Land, Antarctica. A total of 327 samples from 67 plots yielded 11 species of arthropods comprised of three Collembola: Cryptopygus cisantarcticus, Friesea grisea and Isotoma klovstadi and eight mites: Coccorhagidia gressitti, Eupodes wisei, Maudheimia petronia, Nanorchestes sp., Stereotydeus belli, S. punctatus, Tydeus setsukoae and T. wadei. Arthropods were absent from areas occupied by the large Adélie penguin colony. There was some distinction among arthropod communities of different habitats, with water and a lichen species (indicative of scree slope habitats) ranking as significant community predictors alongside spatial variables in a Canonical Correspondence Analysis. Recent changes to the management plan for ASPA No. 106 may need to be revisited as the recommended campsite is close to the area of greatest arthropod diversity.

South Georgia is a highly glacierized island with a range of glacier types including corrie, valley and tidewater ice bodies. Glaciologically, it occupies a strategic location between South America and the Antarctic Peninsula and is potentially an important locality for establishing glacier-climate relationships in the region. Baseline surveys of ice front positions and ice surface profiles have been repeated to determine recent changes in several glacier types. Corrie and small, land-based valley glaciers have continued to thin and recede during the period of study, following an advance during the 1930s. Their behaviour primarily reflects the effects of seasonal temperature variations in controlling net balances, and particularly the climatic warming since 1950. The larger valley and tidewater glaciers display a lagged response and in the 1970s were at their most advanced positions since the Little Ice Age of the 17–19th centuries. However, in the last few years they too have commenced to thin and recede.

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

The McMurdo Dry Valleys of Antarctica are the largest ice-free region on the continent. These valleys contain numerous water bodies that receive seasonal melt from glaciers. For forty years, research emphasis has been placed on the larger water bodies, the permanent ice-covered lakes. We present results from the first study describing the geochemistry of ponds in the higher elevations of Taylor Valley. Unlike the lakes at lower elevations, the landscape on which these ponds lie is among the oldest in Taylor Valley. These upland ponds wax and wane in size depending on the local climatic conditions, and their ionic concentrations and isotopic composition vary annually depending on the amount of meltwater generated and their hydrologic connectivity. This study evaluates the impact of changes in summer climate on the chemistry of these ponds. Although pond chemistry reflects the initial meltwater chemistry, dissolution and chemical weathering within the stream channels, and possibly permafrost fluid input, the primary control is the dilution effect of glacier melt during warmer summers. These processes lead to differences in solute concentrations and ionic ratios between ponds, despite their nearby proximity. The change in size of these ponds over time has important consequences on their geochemical behaviour and potential to provide water and solutes to the subsurface.

Modern diatom samples were collected from 43 sites across the Strømness Bay area of South Georgia. From 115 taxa belonging to 22 six diatom assemblages were distinguished. A CCA-analysis indicated that the assemblages are linked to pH and conductivity ranges, and habitat structure. The Eunotia paludosa var. paludosa - Eunotia subarcuatoides assemblage occurs in small acid water bodies. Samples of the Fragilaria germainii - Pinnularia aff. anglica assemblage are found in pools with a relatively high conductivity. The Fragilaria neoproducta assemblage and the Achnanthes subatomoides - Navicula vitabunda assemblage are mainly found in larger pools and lakes. This relationship between the assemblages and pH was comparable with results found in the testate amoebae fauna of South Georgia.