Pseudochaenichthys georgianus is a member of the unique Channichthyidae family of fishes, which lack haemoglobin. The distribution, length-frequency and summer diet are described from 14 bottom trawl surveys undertaken in the summers between 1986 and 2006. Pseudochaenichthys georgianus (50–590 mm TL) were caught throughout the South Georgia shelf from depths of 76–370 m, but very few specimens (< 1%) were caught on the Shag Rocks shelf. Multiple cohorts were present during each survey and length-frequency analysis of these cohorts suggests that growth is fast during the first 3–4 years. Stomach contents analysis (2005 & 2006) indicated that P. georgianus is a pelagic or semi pelagic predator, with the summer diet dominated by Antarctic krill (Euphausia superba). Fish (channichthyids and notothenids) were also taken, but were a relatively minor part of the diet.

Alpine-type valley and cirque glaciers occur in many massifs in the northern Prince Charles Mountains. A total of forty-seven glaciers have been investigated using maps and aerial photographs, and in the summer of 1991–92 seventeen of these were examined in the field. The distribution of these glaciers and their present-day snowline line altitudes appear to be influenced by their location with respect to snow-bearing winds, particularly the summer winds that bring moisture from the open waters of Prydz Bay. Moraine morphologies indicate that these glaciers advance and retreat out-of-phase with the larger ice sheet outlet glaciers. During the last glacial maximum the alpine-type glaciers retreated while the ice sheet outlet glaciers showed a minor expansion. This is believed to be due to the alpine-type glaciers being starved of snowfall as the expanded last glacial maximum sea-ice cover around the continent would have removed their maritime moisture sources. Recent contrasts in the behaviour of the alpine glaciers may reflect changes in summer sea ice extent in Prydz Bay.

Populations of grey petrels have declined globally due to both incidental capture in commercial fisheries and predation by introduced mammals at breeding sites. In the New Zealand region, grey petrels only breed on Campbell and Antipodes islands. Rats were successfully eradicated from Campbell Island in 2001. We assessed the spatial extent and conducted the first quantitative population estimate of the grey petrel population on Campbell Island and surrounding islets. There was an estimated c. 96 pairs (95% CI: 83, 109) of breeding grey petrels from the four colonies. Since work was conducted during the middle of the chick-rearing stage, this is an underestimate of the breeding population. The Campbell Island grey petrel breeding population remains small. Our study provides a baseline for future population estimates of grey petrels on Campbell Island.

Pringlea antiscorbutica R. Br. (Brassicaceae) and Ranunculus moseleyi Hook. f. (Ranunculaceae) are two species endemic to the subantarctic phytogeographical zone of the south Indian Ocean (Marion and Prince Edward, Crozet, Kerguelen and Heard Islands) (Chastain 1958). The first species is the well-known “Kerguelen cabbage”, and for this taxonomic anomaly a monospecific genus was created (Hooker 1848). The only chromosome count available is by Hamel (1951). The second species Ranunculus moseleyi was first believed to be a strict endemic of the Kerguelen Islands, and then apparently was recorded on Crozet and Marion Islands (Greene & Walton 1975).

The aim of this work was to investigate the effect of different fractions of UVR on two Antarctic marine bacteria (Arthrobacter UVvi and FCB-related UVps strains) and to study the relationship between the bacterial viability and the UVB dose. Ten experiments exposing strains to natural solar radiation were conducted in Potter Cove, South Shetland Islands. The effect of different UVR wavelengths on viability was analysed by using cultures in quartz bottles covered with interferential filters. Six treatments were performed: DARK, PAR (with UVR shielded off), UVA360, UVA320, UVB305 and UVB280. In all UVR treatments, strains showed significant losses of viability under high and moderate irradiance and no differences were observed between UV treatments. Under high UVB dose (15.0 kJ m−2 received in only two hours), the effect of UVB treatments was significantly higher than that observed under UVA treatments. However, UVA caused a significant reduction on bacterial viability. Survival rates were negatively correlated with integrated UVB dose, FCB-related UVps being more sensitive than Arthobacter UVvi. The similar values observed in viability when the same dose was received in different time periods suggested that DNA repair mechanisms are not much effective in these strains. The different response to the UV wavelength ranges studied here suggests that changes in the spectral composition of natural radiation could differentially affect the components of Antarctic marine bacterial communities.

Because of its remoteness, Marie Byrd Land is among the most inaccessible and least visited parts of Antarctica. However, it contains a very poorly studied, large Cenozoic alkaline volcanic province and an outstanding record of volcanism coeval with glaciation (LeMasurier & Thomson 1990). This short note describes the results of the second of two planned periods of fieldwork, which form part of the West Antarctic Volcano Exploration (WAVE) project. The background to WAVE and preliminary results of the 1989–1990 fieldwork are described in Smellie et al. (1990) and McIntosh et al. (1990). The studies described here took place between 2 November 1990 and 11 January 1991.

Erect bryozoans are extremely abundant and diverse in polar waters and individual species may span a wide range in latitude and bathymetry. A number of aspects of lifestyle, including polypide recycling, embryo production, distribution, growth form and epibiosis were compared in three species of erect byozoans. These were collected from two locations; Signy Island (60°S) and Rothera Point, Adelaide Island (68°S) and a variety of depths. All three species were in similar stages of polypide cycling within and between the two sites. In the species Isosecuriflustra rubefacta and Nematoflustra flagellata the rate of brown body production (polypide generations) was slower at Signy Island than at Rothera Point. There was little difference between localities (within species) in the pattern of embryo production and no change in embryo size with depth. Embryos of I. rubefacta, however, were significantly larger at Rothera Point than at Signy Island. The proportion of the community occupied by each species changed with depth, but all three species occurred in shallower water at Rothera Point than at Signy Island. Fouling by epibionts decreased with increasing depth and from Signy Island to Rothera Point, both in terms of per cent cover and number of colonizing taxa. Possible trends with depth and latitude are compared with other studies involving bryozoans. The literature on Antarctic benthic taxa, in general, is also considered to determine whether trends within the Bryozoa are reflected in other groups.

When scientists from HMS Challenger dredged animals from over 5km depth, they finally laid to rest the azoic hypothesis of Edward Forbes, that life could not exist in cold dark depths of theocean, and thereby opened the doors to true deep-sea biology. The past decade has witnessed a furthersea change in our view of marine diversity, if I may be permitted the pun, a change driven to a largeextent by improved knowledge from Antarctica. For many years we viewed the tropics as the enginesof diversity; species arose in warm clear seas, especially those associated with coral reefs, and spreadslowly to populate the harsher high latitudes. Early studies of the isopod fauna had also suggested thatat least some organisms living on the continental shelf of Antarctica may have originated in the deepsea. After a period of intense work, much of it under the auspices of the SCAR EASIZ (Ecology of theAntarctic Sea Ice Zone) and more recently the EVOLANTA(Evolution in Antarctica) programmes, wecan now modify both hypotheses, with powerful implications for our understanding of global marinediversity. The marine invertebrate fauna of the Antarctic continental shelf is now better described thanmight be thought, and the total fauna may well exceed 17000 taxa. Interestingly, there are very fewplaces in the world with comparable data, but we can say that the fauna has had a long history ofevolution in situ and is not simply a last refuge for taxa that originated elsewhere.

Recently Ricci et al. (1993) proposed a series of general guidelines for the naming of igneous and metamorphic rocks in Antarctica, based on discussions held by the SCAR Working Group on Geology. Ricci et al. (1993) suggested that names for igneous and metamorphic rock units should comprise an appropriate geographic name and simple lithological field term. However, they also suggest that names should not include terms that indicate the form or structure of a rock unit, such as dyke, pluton or batholith.

A small freshwater pond near Palmer Station, Anvers Island, (64° 45'S, 64° 05'W) was sampled every 6 h over a 24 h period during the late austral summer to examine changes in both neuston and plankton population levels and activity. Total bacteria using acridine orange and epifluorescence microscopy, counts of viable colony-forming units, and chlorophyll a were determined. Activity was estimated by measuring the rate of 3H-thymidine incorporation. The data indicate that over this time period the bacterioneuston populations went through a diel fluctuation and temperature may be an important factor in this cycle. Although the bacterioneuston populations were often more numerous than corresponding plankton populations, subsurface bacteria appeared to be metabolically more active.

Measurements of snow accumulation are critical for reliable prediction of future ice mass loss and hence projections of sea level change. However, there are currently very few published in situ measurements of snow accumulation in the Pine Island–Thwaites glacier catchment of the Amundsen Sea Embayment, and none from low elevation sites west of 100.77° longitude. Here measurements of snow accumulation over an 11 month period in 2016 are reported for six sites in the Pine Island–Thwaites glacier catchment. The average accumulation rates of 0.10±0.01 to 1.26±0.22 m w.e. yr-1 are comparable with those derived from airborne radar for the period 1985–2009, suggesting very high rates of snowfall, particularly in the vicinity of the grounding line.

Palaeostress inferred from brittle mesostructures in Seymour (Marambio) Island indicates a Cenozoic to Recent origin for an extensional stress field, with only local compressional stress states. Minimum horizontal stress (σ3) orientations are scattered about two main NE–SW and NW–SE modes suggesting that two stress sources have been responsible for the dominant minimum horizontal stress directions in the north-western Weddell Sea. Extensional structures within a broad-scale compressional stress field can be linked to both the decrease in relative stress magnitudes from active margins to intraplate regions and the rifting processes that occurred in the northern Weddell Sea. Stress states with NW–SE trending σ3 are compatible with back-arc extension along the eastern Antarctic Peninsula. We interpret this as due to the opening of the Larsen Basin during upper Cretaceous to Eocene and to the spreading, from Pliocene to present, of the Bransfield Basin (western Antarctic Peninsula), both due to former Phoenix Plate subduction under the Antarctic Plate. NE–SW σ3 orientations could be expressions of continental fragmentation of the northern Antarctic Peninsula controlling eastwards drifting of the South Orkney microcontinent and other submerged continental blocks of the southern Scotia Sea.

Aquatic ecosystems - lakes, ponds and streams - are hotspots of biodiversity in the cold and arid environment of Continental Antarctica. Environmental change is expected to increasingly alter Antarctic aquatic ecosystems and modify the physical characteristics and interactions within the habitats that they support. Here, we describe physical and biological features of the peripheral ‘moat’ of a closed-basin Antarctic lake. These moats mediate connectivity amongst streams, lake and soils. We highlight the cyclical moat transition from a frozen winter state to an active open-water summer system, through refreeze as winter returns. Summer melting begins at the lakebed, initially creating an ice-constrained lens of liquid water in November, which swiftly progresses upwards, creating open water in December. Conversely, freezing progresses slowly from the water surface downwards, with water at 1 m bottom depth remaining liquid until May. Moats support productive, diverse benthic communities that are taxonomically distinct from those under the adjacent permanent lake ice. We show how ion ratios suggest that summer exchange occurs amongst moats, streams, soils and sub-ice lake water, perhaps facilitated by within-moat density-driven convection. Moats occupy a small but dynamic area of lake habitat, are disproportionately affected by recent lake-level rises and may thus be particularly vulnerable to hydrological change.

Laccases are enzymes from the multi-copper oxidase family that have gathered a lot of attention due to their wide range of substrates, their interspecies variability and their still elusive mechanism of action. The presence of four copper atoms in their active site makes them an interesting model for the study of the relationship between the structure and function of proteins. It is possible to find them in fungi, plants and prokaryotes. Bacterial laccases display many advantages over fungal laccases in terms of their application. They have, in general, a greater thermal stability and a different pH profile, which contributes to widening their field of possible application. In the present work, a novel laccase from an Antarctic microorganism, Geobacillus sp. ID17, is purified and characterized. This is the first Antarctic bacterial laccase to be functionally described. It was found to be active at neutral pH and to have greater activity at 55°C. Its catalytic constants are in the order of other bacterial laccases. Screening for different potential substrates was also performed, showing that this novel laccase is more selective than commercial laccases. This enzyme could find potential application in the generation of gallic acid polymers or in organic synthesis in contexts where meticulous substrate discrimination is needed.

Like every other continent in the world, Antarctica has been affected by the COVID-19 pandemic, in an imagined as well as a practical sense. Antarctica is a mediated experience; that is, most of us experience the place through films, novels, music, visual arts and the media. We present an analysis of media articles from eight countries over three time periods - pre-COVID-19 outbreak (October–December 2019), shortly after the pandemic hit the headlines (March–May 2020) and when the virus was established (October–December 2020) - to discover how COVID-19 may have changed Antarctic discourse. Our study shows that representations of Antarctica have been affected by the pandemic, in some instances reinforcing existing ideas and in other cases bringing new ideas to the fore. Based on our findings, we believe that COVID-19 has begun to change representations of Antarctica, stepping us away from the prevailing Antarctic hero narrative and providing a more contemporary understanding of the Antarctic experience. We argue that this may increase our motivation to engage with Antarctic issues, with associated implications for future global stewardship of the region.

Antarctic and Southern Ocean environments are facing increasing pressure from multiple threats. The Antarctic Treaty System regularly looks to the Scientific Committee on Antarctic Research (SCAR) for the provision of independent and objective advice based on the best available science to support decision-making, policy development and effective environmental management. The recently approved SCAR Scientific Research Programme Ant-ICON - ‘Integrated Science to Inform Antarctic and Southern Ocean Conservation‘ - facilitates and coordinates high-quality transdisciplinary research to inform the conservation and management of Antarctica, the Southern Ocean and the sub-Antarctic in the context of current and future impacts. The work of Ant-ICON focuses on three research themes examining 1) the current state and future projections of Antarctic systems, species and functions, 2) human impacts and sustainability and 3) socio-ecological approaches to Antarctic and Southern Ocean conservation, and one synthesis theme that seeks to facilitate the provision of timely scientific advice to support effective Antarctic conservation. Research outputs will address the most pressing environmental challenges facing Antarctica and offer high-quality science to policy and advisory bodies including the Antarctic Treaty Consultative Meeting, the Committee for Environmental Protection and the Scientific Committee of the Commission for the Conservation of Antarctic Marine Living Resources.

Scanning electron microscope and image analysis techniques were used to construct a profile of otolith growth from June 1987–June 1988 in immature Notothenia coriiceps. Growth was found to fluctuate seasonally with a large decrease between August and late November 1987. Examination of stomach fullness showed that fish continued to feed during winter. Increases in absolute light levels and sea temperature during spring were found to coincide approximately with increasing growth. Conclusive evidence distinguishing between hypotheses for limitation of growth either by seawater temperature or by resource availability was not found.