CCl3F (or CFC-11) and CCl2F2 (or CFC-12) were determined in air samples collected, during subsequent summer Antarctic campaigns, in different sampling sites in the Ross Sea Region. The samples were analysed by GC-ECD after enrichment. Data obtained since 1988–89 were plotted to observe the trend of CFCs atmospheric concentration levels. A decrease in the rate of increase of CFC-12 concentration was observed, whilst the concentration of CFC-11 was actually seen to be decreasing.

Virus diversity in Antarctic biotopes remains understudied. Here, we describe bacteriophages isolated from terrestrial environments, provide data on their natural bacterial hosts and study phage-host systems. Six bacterial isolates (FCKU 539, FCKU 533, FCKU 534, FCKU 538, FCKU 542 and FCKU 540) were recovered and characterized. Isolated bacteria belonged to Pseudomonas genus (Pseudomonas sp., Pseudomonas fluorescens, Pseudomonas putida) with optimal cultivation temperatures of 16–28°C. These bacteria and previously described Bacillus subtilis FCKU 537 were used for analysing virus-host interactions. Six lytic phages were isolated and named P. fluorescens Antarctic virus 1 (PFAV1), P. fluorescens Antarctic virus 2 (PFAV2), P. fluorescens Antarctic virus 3 (PFAV3), P. putida Antarctic virus 4 (PPAV4), Pseudomonas sp. Antarctic virus 5 (PSAV5) and B. subtilis Antarctic virus 6 (BSAV6) in relation to their natural hosts. According to electron microscopy data, these phages belonged to Caudovirales order. Cross-inoculation demonstrated high specificity of all Antarctic phages, which infected only their initial hosts at moderate temperatures. PFAV2 and PFAV3 phages also infected laboratory Pseudomonas savastanoi and P. fluorescens isolates. This paper adds new data on the occurrence and diversity of viruses and their respective bacterial hosts in soil biotopes of Antarctica.

Sediment trap arrays were deployed in Brialmont Cove and Andvord Bay, eastern Gerlache Strait, from December 2001–March 2003. The recovered sediments (representing instantaneous deposition from the viewpoint of luminescence dating) encompass all the annual and local glaciomarine depositional processes. Magnetic susceptibility profiles were used to infer seasonality in the trap cores, and thus to select subsamples for luminescence measurements. Multi-aliquot infrared stimulated luminescence (IRSL) apparent ages were used to assess the effectiveness of ‘clock zeroing’ (by daylight) of light sensitive luminescence within fine silt polymineral samples from each trap depth. IRSL apparent ages for 24 samples indicate that the largest age-depth differences occur with the autumn season samples at both trap sites, suggesting a previously unrecognized and regional (within the Gerlache Strait) change in depositional controls in the autumn compared to other seasons. The apparent ages also indicate some differences between the fjords, and a more complex oceanographic regime at Andvord Bay than at Brialmont Cove. Dry-mass sediment fluxes varied from 0.4 to 0.7 g cm-2 yr-1, with the largest flux at Brialmont Cove (∼0.7 g cm-2 yr-1) occurring in the bottom trap, whereas at Andvord Bay, the largest flux (∼0.6 g cm-2 yr-1) occurred in the middle trap (∼45 m above seafloor).

The Antarctic Treaty System requires that the effects of potential human disturbance be evaluated, such as through the development and evaluation of Initial and Comprehensive Environmental Evaluations (IEEs and CEEs), and through the implementation of Management Plans for Antarctic Specially Protected Areas (ASPAs) and Antarctic Specially Managed Areas (ASMAs). The effectiveness of these management processes hinges on the quality and transparency of the data presented, particularly because independent validation is often difficult or impossible due to the financial and logistical challenges of working in the Antarctic. In a review of these documents and their treatment of wildlife survey data, we find that the basic elements of best data practices are often not followed; biological data are often uncited or out-of-date and rarely include estimates of uncertainty that would allow any subsequent changes in the distribution or abundance of wildlife to be rigorously assessed. We propose a set of data management and use standards for Antarctic biological data to improve the transparency and quality of these evaluations and to facilitate improved assessment of both immediate and long-term impacts of human activities in the Antarctic.

The Antarctic gastropod Dickdellia labioflecta (Dell, 1990) (originally described as Laevilittorina (Corneolittorina) labioflecta) is an obligate parasite of pycnogonids, which exploits their body fluids through the cuticular gland holes (Lehmann et al. 2007) and lays its eggs on the pycnogonid's legs where embryos complete their life cycle (Hedgpeth 1964, Sirenko 2000, Lehmann et al. 2007). The ecology of D. labioflecta appears to be unique, as no other examples of such a specialized parasitic behaviour on pycnogonids are known. This life-style and the related anatomical specializations (gut and digestive gland morphology), prompted the erection of a new genus, Dickdellia Warén & Hain, 1996 provisionally included in the family Zerotulidae (Warén & Hain 1996). Although information is quite scant, to date, two pycnogonid host species are known for Dickdellia: Colossendeis megalonyx megalonyx Fry & Hedgpeth, 1969 (Lehmann et al. 2007) and Nymphon isabellae Turpaeva, 2000 (Sirenko 2000).

The genus Pogonophryne is the most species-rich genus of barbeled plunderfishes (Artedidraconidae) and includes more than 25 poorly known species endemic to the Southern Ocean. In this study, we provide new data on the age and reproductive traits of some species of Pogonophryne from the southern Weddell Sea, inferred through otolith reading and histological analyses of gonads. Individual age estimates ranged between 16 and 18 years for Pogonophryne barsukovi and Pogonophryne immaculata and between 10 and 22 years for Pogonophryne scotti. As is commonly found in notothenioids, P. barsukovi followed a group-synchronous type of ovarian development, with pre-vitellogenic and vitellogenic oocytes forming two well-separated egg-size groups. A single spawning female in the sample produced ~1097 eggs and 7.9 eggs g-1. The sample of P. immaculata consisted exclusively of developing males, with testes composed of cysts of spermatogonia, spermatocytes and spermatids. Pogonophryne scotti was the most abundant species, including relatively small males at immature or developing stages of gonad development. Larger females were regressing, being characterized by ovaries with postovulatory follicles and atretic oocytes. Based on the macroscopic and histological analyses of gonads, the spawning season would take place in autumn for P. barsukovi and P. immaculata and in spring–early summer for P. scotti.

Among the longest Antarctic biological time series is that of Adélie penguin Pygoscelis adeliae population size at Cape Royds, 1955 to the present. Demographic trends over the 66 years fall into five periods: 1) decrease then recovery due to control of tourism from McMurdo Station/Scott Base; 2) further increase responding to the removal of > 20 000 trophically competing Antarctic minke whales Balaenoptera bonaerensis from the colony's wintering area; 3) stabilization but not decrease upon the ban of whaling in 1982, and whale recovery, owing to increased winds facilitating McMurdo Sound Polynya presence (easier ocean access during nesting); 4) decrease in 2001–2005 when two mega-icebergs, B15A/C16, opposed the wind effect by increasing sea-ice cover, thus limiting ocean access; and 5) after iceberg departure, minimal recovery due to the increased velocity of the wind-generated Ross Gyre reducing penguin breeding probability. A multivariant model using 1998–2018 data confirmed the roles of gyre speed (negative) and open water (positive) in colony growth. Additional negative influence came from high nest predation by south polar skuas Stercorarius maccormicki, reducing chick production, as well as perhaps increased trophic competition from nearby Weddell seals Leptonychotes weddellii. Clearly, long time series increase our understanding of penguin population dynamics responding to a complexity of factors.

Polar subglacial hydrologic systems have garnered much interest since the recognition of Lake Vostok in 1996. In Antarctica, these environments are hydrologically diverse, including isolated lakes of different sizes, river–lake flow-through systems, “swamps” and groundwater (Siegert 2016). The refreezing of subglacial meltwater is also an important process beneath a large portion of the East Antarctic Ice Sheet (Bell et al. 2011). As subglacial water refreezes it exsolves salts, potentially leaving behind saline and hypersaline brines. Brines thought to derive from this cryoconcentration process have been observed in the northern polar permafrost regions and in the McMurdo Dry Valleys (MDVs) region of Antarctica. Additionally, sediments in the Victoria Land Basin have diagenetic signatures produced by brine movement dating from 3–11 m.y.a, suggesting hypersaline brines have existed in the McMurdo region since at least this time (Staudigel et al. 2018).

Lake Untersee is a perennially ice-covered Antarctic lake that consists of two basins. The deepest basin, next to the Anuchin Glacier is aerobic to its maximum depth of 160 m. The shallower basin has a maximum depth of 100 m, is anoxic below 80 m, and is shielded from convective currents. The thermal profile in the anoxic basin is unusual in that the water temperature below 50 m is constant at 4°C but rises to 5°C between 70 m and 80 m depth, then drops to 3.7°C at the bottom. Field measurements were used to conduct a thermal and stability analysis of the anoxic basin. The shape of the thermal maximum implies two discrete locations of energy input, one of 0.11 W m-2 at 71 m depth and one of 0.06 W m-2 at 80 m depth. Heat from microbial activity cannot account for the required amount of energy at either depth. Instead, absorption of solar radiation due to an increase in water opacity at these depths can account for the required energy input. Hence, while microbial metabolism is not an important source of heat, biomass increases opacity in the water column resulting in greater absorption of sunlight.

It is well established that the reaction of HO2 with NO plays a central role in atmospheric chemistry, by way of OH/HO2 recycling and reduction of ozone depletion by HOx cycles in the stratosphere and through ozone production in the troposphere. Utilizing a photochemical box model, we investigate the impact of the recently observed HNO3 production channel (HO2+NO → HNO3) on NOx (NO + NO2), HOx (OH + HO2), HNO3, and O3 concentrations in the boundary layer at the South Pole, Antarctica. Our simulations exemplify decreases in peak O3, NO, NO2, and OH and an increase in HNO3. Also, mean OH is in better agreement with observations, while worsening the agreement with O3, HO2, and HNO3 concentrations observed at the South Pole. The reduced concentrations of NOx are consistent with expected decreases in atmospheric NOx lifetime as a result of increased sequestration of NOx into HNO3. Although we show that the inclusion of the novel HNO3 production channel brings better agreement of OH with field measurements, the modelled ozone and HNO3 are worsened, and the changes in NOx lifetime imply that snowpack NOx emissions and snowpack nitrate recycling must be re-evaluated.

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.

Simultaneous acoustic Doppler sodar and tethersonde measurements were used to study some of the characteristics of the unstable boundary layer at Dumont d'Urville, Adélie Land, East Antarctica during the summer 1993–94. A description of the convective boundary layer and its behaviour in connection with the wind regime is given along with the frequency distribution of free convection episodes. The surface heat flux has been evaluated using the vertical velocity variance derived from sodar measurements. The turbulent exchange coefficients, estimated by coupling sodar and tethered balloon measurements, are in strong agreement with those present in literature for the Antarctic regions.

Differences in the decadal trend in the winter surface temperature in the northern and southern Antarctic Peninsula have been analysed. Time series from the two stations Esperanza and Faraday/Vernadsky since the early 1950s are used. The two time series are strongly correlated only during the 1980s and 1990s when their variability and trends are associated with both the Niño-4 region and Southern Annular Mode impacts. The winter cooling at the Faraday/Vernadsky station contrasts with the winter warming at the Esperanza station during the period of 2006–17. The different temperature trends are accompanied by weak correlations between the temperatures at these two stations. Linearly congruent components of the station temperature trends in 2006–17 indicate a dominant contribution of Southern Annular Mode (tropical sea surface temperature anomalies) to warming (cooling) in the northern (southern) Peninsula. Distinctive impacts of climate modes are observed in combination with the recent deepening of the negative sea-level pressure anomaly to the west of the peninsula and the related change in the zonal and meridional wind components. These factors apparently contribute to the occurrence of the boundary that crosses the peninsula and divides it into sub-regions with warming and cooling.

We report the first formal record of the Indian meal moth Plodia interpunctella from a location within the Antarctic Treaty area, with the capture of a live adult male within the Brazilian Comandante Ferraz research station on King George Island, South Shetland Islands. This species is a well-known pest of stored products and is widely recorded in synanthropic situations such as food stores globally. No other adults or immature stages have been observed on the station. While there is no suggestion that P. interpunctella could survive or establish in the natural environment beyond the station, this observation highlights the ever-present threat of unintended anthropogenically assisted transfer of non-Antarctic species into human facilities on the continent, with some such species proving extremely difficult to eradicate if they successfully establish within these facilities.

Three temporary Automatic Weather Stations measured summertime surface layer climate over the Darwin–Hatherton Glacial system. These data were used to test a Polar optimized Weather Research and Forecasting model (Polar-WRF) simulation for December as a case study. Observations show differences in hourly averaged solar and net all-wave radiation between white ice and blue ice areas (BIAs). Although the down-welling solar radiation is higher over the white ice region, the net all-wave energy is higher over the BIA. Derived albedo for each surface type confirms that the blue ice areas have lower albedo. Also, the hourly averaged temperatures are higher at lower elevation stations, creating a gradient towards the Ross Ice Shelf. Analysis shows that there is a diurnal oscillation in strength and intensity of the katabatic wind. The two lower stations register a distinct reversal of wind direction in the early afternoon due to intrusion of an anabatic circulation. Anabatic winds are not prevalent further up the Darwin Glacier. A high-resolution Polar-WRF simulation as a case study shows good agreement with observations. The December 2008 case study is characterized by a strong south-westerly katabatic wind over Hatherton, whereas the flow over Lower Darwin was diurnally reversing. Polar-WRF shows that the katabatic front advanced and retreated periodically between Hatherton and Lower Darwin.

The new genus and species Bicoloromyces kyffinensis is described as new to science from a sterile crustose lichen, perhaps Lecanora fuscobrunnea or Lecidella sp. from Ebony Ridge of Mount Kyffin, Antarctica. The fungus recalls superficially the lichenicolous species referred to Taeniolella, but differs in having semi-macronematous conidiophores, tissues encrusted with calcium oxalate, aeruginose to blue-black colouration under the microscope, and conidia which are distoseptate and formed in basipetal chains. Energy dispersive spectroscopy established that the encrustations were of calcium oxalate. Differences from genera of rock-inhabiting fungi described from the Antarctic are discussed. This appears to be the furthest south any lichen-inhabiting fungus has been reported.

Due to its geographic isolation and relatively limited human impact, Antarctica is a promising location to study the eco-physiology of natural halogen cycles. Anaerobic sediments from Antarctic melt ponds on Ross Island and on the McMurdo Ice Shelf near Bratina Island were tested for activity of microbial reductive dehalogenation. Anaerobic enrichment cultures were established with potential electron donors and tetrachloroethene, trichloroethene, 2-bromophenol, 2-chlorophenol, 3-bromobenzoate, or 3-chlorobenozoate, as model halocarbon electron acceptors. Dechlorination of aromatic compounds was limited, whereas 2-bromophenol was debrominated in seven of the eight sediments and one site also showed debromination of 3-bromobenzoate. A most probable number estimate with 2-bromophenol at one site revealed 103–104 cultivatable debrominators per gram of sediment (wet weight). Chloroethene dechlorination was slow and primarily produced trichloroethene from tetrachloroethene, although both cis- and trans-dichloroethene were detected in certain enrichments upon extended incubation. These results demonstrate the presence of reductive dehalogenating activity in anaerobic, Antarctic melt-pond sediments and expand the known metabolic diversity of Antarctic microorganisms.

No less than 15–20 sedimentary basins are now known on the Antarctic continental landmass and surrounding continental shelves. Reconstruction of their tectonic and stratigraphic evolution is a specialized task. Owing to the polar position of the continent, the Pacific and Atlantic global geostructures are closely spaced there and the interplay between them is strong enough to result in hybridization of the characteristic tectonic features of the various basins. The present morphostructure of the southern polar region of the Earth is characterized by a prominent circumpolar zoning. Therefore, the sedimentary basins form a gigantic ring along the continental margin, including both the shelf proper and the edge of the continent. Within the ring, the basins are associated with different types of margins successively replacing each other, from the Mesozoic magmatic are in the Pacific segment to the classic passive margin off East Antarctica. The formation of the sedimentary basins in the Antarctic segment of the Pacific mobile belt was a part of a single process of geosynclinal development, whereas on the craton flank the process was superposed on the continental structures by rifting during Gondwana fragmentation. During post-break-up tectonism, continental glaciation played an important part in the formation of the sedimentary basins.

Variations in atmospheric conditions can be important factors influencing temperature dynamics within the active layer of a soil. Solar radiation and air temperature can directly alter ground surface temperatures, while variations in wind and precipitation can control how quickly heat is carried through soil pores. The presence of seasonal snow cover can also create a thermal barrier between the atmosphere and ground surface. This study examines the relation between atmospheric conditions and ground temperature variations on a deglaciated island along the Western Antarctic Peninsula. Ground temperatures were most significantly influenced by incoming solar radiation, followed by air temperature variations. When winter months were included in the comparison, the influence of air temperature increased while solar radiation became less influential, indicating that snow cover reflected solar radiation inputs, but was not thick enough to insulate the ground. When ground temperatures were compared to atmospheric conditions of preceding weeks, seasonal temperature peaks 1.6 m below ground were best related to seasonal air temperature peaks from the previous two weeks. The same ground temperature peaks were best related to seasonal solar radiation peaks of seven weeks prior. This difference was a result of temperature lags within the atmosphere.

During summer (2 December 1999–23 January 2000) an Ocean Surface Current Radar (OSCR-II) was used to provide surface current measurements within the Terra Nova Bay polynya, one of the most important coastal polynyas of the Ross Sea. This represents an important step towards a continuous monitoring of the area. Useful information is now available as a basis for future work in this field, although the two radar sites, necessary to calculate the total current vector, did not work together throughout the whole period of the experiment as one of the units was damaged. The results demonstrate the feasibility of this kind of measurement and suggest that very important dynamical characteristics of the polynya could be deduced from long term deployment of such a system.