The southern giant petrel (Macronectes giganteus) is a widely distributed top predator of the Southern Ocean. To define the fine-scale foraging areas and habitat use of Antarctic breeding populations, 47 southern giant petrels from Nelson Island were GPS-tracked during the summers of 2019–2020 and 2021–2022. Step-selection analysis was applied to test the effects of environmental variables on habitat selection. Visual overlap with seal haul-out sites and fishing areas was also analysed. Birds primarily used waters to the south of the colony in the Weddell and Bellingshausen seas. Females showed a broader distribution, reaching up to -70°S to the west of Nelson Island, while males were mainly concentrated in waters off the northern Antarctic Peninsula. Habitat selection of both sexes was associated with water depth and proximity to penguin colonies. Both overlapped their foraging areas with fishing sites and females in particular overlapped with toothfish fishery blocks in Antarctica and with fishing areas in the Patagonian Shelf. Due to their habitat associations and overlap with fisheries, when harnessed with tracking devices and animal-borne cameras, giant petrels can act as platforms for monitoring the condition and occurrence of penguin colonies, haul-out sites and unregulated fisheries on various temporal and spatial scales in Antarctica.

We assessed the content of some major and trace elements and lichen compounds as well as antioxidant activity in eight lichen species representing four families collected in areas > 1 km distant from Bellingshausen (King George Island) and > 1 km distant from Molodezhnaya (Thala Hills, Enderby Land) research stations. Content levels of Cu, Pb, Cd, Zn and As in Physcia caesia, Physconia muscigena, Umbilicaria aprina, Umbilicaria decussata and Usnea aurantiaco-atra thalli were similar to or lower than previously reported for these species in the Maritime and Continental Antarctic, as well as from reference sites. The first data on the contents of 15 elements in Ramalina terebrata and Thamnolecania brialmontii thalli from the Maritime Antarctic are reported. Our analyses confirmed the presence of the main photosynthetic pigments in the species examined (chlorophyll a and b, phaeophytin a and b, neoxanthin, violaxanthin, lutein and β-carotene). We identified protolichesterinic acid in T. brialmontii thalli for the first time. Antioxidant activity varied from 190 μg/g dry weight (U. decussata) to 14,740 μg/g dry weight (T. brialmontii). The data obtained complement previous research while also providing new baseline data that will have utility in monitoring and identifying future change.

Antarctica is considered the most isolated continent, but it is not free of pollution, which arrives at specific localities mainly as a result of tourism and research activities. Among environmentally harmful substances, heavy metals are especially important because of their high toxicity to organisms. The aim of this study was to estimate the maximum adsorption of lead (Pb) onto the clay fraction of samples from two soil profiles from the Fildes Peninsula, King George Island, South Shetland Islands. Experimental data were fitted to the Langmuir isotherm, and the adsorption parameters were correlated to mineralogical attributes of this soil fraction characterized by chemical extractions and X-ray diffraction. Values of maximum adsorption of Pb in the clay fraction were extremely high (maximum value: 322 581 mg kg-1) when compared to those of soil samples from other regions of the world. Adsorption occurred in two stages: first stage in which a high percentage of Pb was adsorbed, and second stage in which adsorption was lower. From an environmental point of view, soils with high contents of clay and amorphous minerals, ones usually associated with ornithogenic activity in Antarctica, should have greater efficiency in filtering Pb, thus reducing risks of leaching and groundwater contamination.

A small, inconspicuous lichen, Acarospora cf. badiofusca, was discovered colonizing iron-stained quartz mica schists on the lower slope of Manhaul Rock, a recently exposed nunatak on the McLeod Glacier, Signy Island, South Orkney Islands. Thallus colour ranged from rust on exposed rock surfaces to paler orange and green in shaded crevices. This study addressed the hypothesis that colour reflects element localization, and considered substance localization within lichen tissues and responses to stress. Electron microprobe analysis of specimens confirmed that Fe is localized principally in the outer rust-coloured part of the cortex, confirming that the colour reflects Fe localization. Oxalates, widely reported as contributing to tolerance mechanisms to environmental stress, were not detected using X-ray diffraction. The upper thallus surface consisted of sub-micron particulate phases containing Fe, Al and O, suggesting mixed oxide/hydroxide phases are present and play a role in photoprotection.

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.

Aerial dispersal has been frequently proposed as a potential mechanism by which polar terrestrial arthropods are transported to, and settle the ice free habitats of Antarctica, but to date there has been little substantive evidence in support of this hypothesis. Using water traps we investigated aerial deposition of arthropods on Lagoon Island, Ryder Bay, on the Antarctic Peninsula. Over a period of five weeks, trapping at three different altitudes, we captured a total of nine springtails, Cryptopygus antarcticus, all alive. This is the first study to demonstrate conclusively the survival of wind-borne native arthropods within Antarctica. By scaling the modest trapping area and success against island surface area, it is clear that hundreds, if not thousands, of springtails are regularly relocated by winds between the terrestrial habitats of Marguerite Bay. We use known desiccation rates of C. antarcticus and wind speeds to predict the likelihood of successful dispersal between the principal terrestrial habitats of the larger Marguerite Bay. Implications for local and long-range dispersal are discussed in relation to C. antarcticus and other polar arthropods.

We provide the first comprehensive account of habitat preference, mating, oviposition and developmental stages of Parochlus steinenii. There are eight records from the South Shetland Islands. On King George Island, none out of 40 temporary ponds and 9% out of 44 lakes with variable water levels were inhabited by P. steinenii. By contrast, 94% of 52 lakes with stable water levels were occupied, for 92% of which breeding was confirmed. Lakes were occupied independently of their height above sea level ranging from 5 to 115 m. The midges aggregated at two different microhabitats at the shoreline of lakes. Terrestrial swarms of more than 5000 individuals at open wind sheltered rocks were strongly dominated by males. Their mean density was 40, their maximum 150 ind. cm−2. Aggregations under stones at the water edge showed a female-biased or equal sex ratio; their densities seasonally increased from 0.17 to 2.02 ind. cm−2. Female midges produced one to four egg batches totalling on average 247 eggs/female. Four larval stages can be clearly discriminated by head length. Our data on the habitat preferences and the high reproductive output predict that P. steinenii will rapidly colonize habitats that become available in the course of the regional warming of the Antarctic Peninsula region.

Placopsis antarctica, which is apparently endemic to antarctic regions south of lat. 60°S (South Orkney Is, South Shetland Is and the Antarctic Peninsula), is described. Details of its morphology, anatomy, chemistry, ecology and distribution are given. Placopsis bicolor is newly reported from South Georgia. A revised key to species of Placopsis occurring in South Georgia and Antarctica is given.

Juvenile development has been investigated for the first time in an Antarctic lichen species—Usnea antarctica—in the northern maritime Antarctic, Livingston Island (South Shetland Islands, 62°27′–62°48′S, 59°45′–61°15′W). Here, U. antarctica grows on rocks and forms the dominant vegetation on this site together with a few other macrolichens. This species reproduces mainly by vegetative diaspores (soredia), which include both the photobiont and the mycobiont. To understand the early ontogenetic strategies in U. antarctica, culture experiments were performed in an Antarctic field site where the species occurs naturally. This paper focuses on the different developmental steps seen between the initial colonization of soredia to the formation of a small well-developed thallus, and also on the growth rate of the respective juvenile stages. Compared with growth rates of lichens from temperate European regions the early development of U. antarctica is extraordinarily slow, taking 5–6 years until an adult thallus has been formed. The low photobiont content in the juvenile stages probably limits the growth rate. It is suggested that juvenile development of U. antarctica is controlled by a combination of ecophysiological and morphological adaptations that are required for success in extreme environments such as the terrestrial habitats of the Antarctic.

Halozetes belgicae is distributed widely in the Subantarctic and maritime Antarctic, with subspecies described from Macquarie Island and the South Sandwich Islands. A morphometrical study, based largely on the development of the setae, indicates that the nominate subspecies is confined to the Antarctic Peninsula and its offshore islands (including the South Shetland Islands), whilst specimens from the South Orkney Islands are probably consubspecific with individuals on the South Sandwich Islands. In comparison with other studies of the Acari, the results strengthen the case for the recognition of a South Orkadian biogeographical zone.

Five species of Umbilicaria are described, three of which, U. africana, U. krascheninnikovii and U. nylanderiana, have not been previously recorded from Antarctica. Distributional patterns and morphological characteristics of these species are discussed.

Photosynthetic photon flux density (PPFD), air relative humidity and thallus temperature (TT) were measured in Usnea antarctica over a period of 12 months at a coastal rock on King George Island, South Shetland Islands. TT had an annual amplitude of c. 54 K with the maximum of +27.4°C recorded in December and minimum of −27.3°C in July. Daily maximum TT exceeded 0°C every month except in June and July when they were below −0.4°C and −1.6°C, respectively. Daily minimum temperatures were always below zero. Diel courses of PPFD showed pronounced seasonal differences between summer (more than 2000 μmol m−2s−1) and winter (less than 50 μmol m−2s−1 in July). Daily sum of PPFD was highest (more than 30 mol m−2d−1) in December and lowest (0.1 mol m−2d−1) in July. A photosynthesis model was used to estimate the potential annual primary production from habitat PPFD and TT. The estimated potential annual carbon balance of U. antarctica was 323 mg CO2 g−1 dry weight y−1 assuming that the lichen was always at optimal moisture. The potential carbon balance indicates that primary production is severely limited by low PPFD and subzero TT in the austral winter. Nevertheless, the PPFD and TT would allow metabolic activity during winter but with a negative carbon balance during May–August. Spring and autumnal months are revealed as probably the most important periods for lichen primary production because PPFD exceeds photosynthetic light compensation point during the daytime and ambient moisture conditions frequently favour a positive carbon balance.

Classification of 162 sample plots of lichen vegetation from the Argentine Islands region, Antarctica, yielded two main groups, the Usnea complex and the Mastodia-Rinodina complex, comprising four and six subordinate communities, respectively. Communities of the Usnea complex typically occur in inland sites with steep slopes, characterized by low chloride, ammonia and phosphate concentrations. Communities of the Mastodia-Rinodina complex occur close to the shore and in areas occupied by birds, where concentrations of chloride, ammonia and phosphate were relatively high. Within each vegetation complex species composition is related to factors indicating nutrient status (chloride and ammonia concentration, distance from the sea), as well as to variables indicating different microclimatic conditions (elevation, aspect, exposure, moisture, and gradient). In canonical correspondence analyses of the data a large part of species variation could not be explained by the environmental variables studied (elevation, gradient, slope aspect, distance from the sea, direction of the sea, presence of guano, exposure, moisture, chloride, ammonia, phosphate and nitrate concentrations). It is suggested that temporal variability in mineral concentrations and the lack of information on differences in length of the growing season at the sample sites are, to a large extent, responsible for this.

Field surveys of free-living terrestrial microarthropods were made during the 1994–95 summer at four sites in northern Marguerite Bay (Anchorage Island, Lagoon Island, Léonie Island, Rothera Point; c. 68°S, 68°W) and three on southern Alexander Island (Two Step Cliffs, Fossil Bluff, Ablation Valley; c. 71–72°S, 68°W). Detailed site descriptions are presented, as little previous information exists. Twenty species (four Collembola, 16 Acari) were recorded from the Marguerite Bay sites, with a maximum of 17 species at one site. A further four species (one Collembola, two Acari, one Diptera) have been recorded from the same area by other authors. Species diversity at these sites, in particular Léonie Island, is as great as at any known site elsewhere in the maritime Antarctic, although the total area of terrestrial habitat available is small. Individual species and total population densities are also similar to, if not greater than, published studies from the South Shetland and South Orkney Islands. None of the species is new to the maritime Antarctic, although the distributions of several are extended southwards. Only nine species (maximum seven at one site) were found on Alexander Island, concurrent with decreases in population densities to levels similar to those found in many continental Antarctic studies. This still represents a high species diversity for such a high latitude site. The richness of two sites, Ablation Valley and Mars Oasis (Two Step Cliffs), is unlikely to be repeated elsewhere on Alexander Island. The Alexander Island fauna is clearly related to that of the maritime Antarctic, as all except one species occur at more northerly sites elsewhere on the Antarctic Peninsula, and none in the continental Antarctic. One species, Friesia topo (Collembola), is known only from Alexander Island.

A general study of the streams of Signy Island, South Orkney Islands, was undertaken to identify the effects of catchment, distance from source, and time on concentrations of dissolved ions. In the majority of cases catchment did not affect the chemistry of streams, although marine-derived ions were affected by distance from the sea. Na+, K+, Mg2+, Ca2+, Cl− and NH4+were derived from the thawing of the winter snowpack. NO3− was derived from areas of permanent ice. SiO44−, Ca2+, Mg2+ and CO2−3 were derived from crustal weathering. Although PO43− was also derived from crustal weathering, it was released as a pulse related to the thawing of the soil.

Body size, geographical distribution and biomass make Laternula elliptica one of the most important bivalve species of the Antarctic. A complete study on the population dynamics (reproduction cycle, growth, mortality and productivity) of this species from King George Island gave growth parameters for the von-Bertalanffy-growth-function of: L∞ = 112.2 mm, K = 0.160 yr 1, t0 = 0.000 yr. Total mortality was estimated as Z = 0.392 yr−1. Somatic production and mean biomass of two distinct sub-populations were 8.7 and 67.3 g AFDW m−2 yr−1 at Beach & Glacier and 20.0 and 88.6 g AFDW m−2 yr−1 at Punta Elefante. The following P / B values were calculated; Beach & Glacier = 0.129, Punta Elefante = 0.226. It is suggested that these differences are linked to mortality caused by icebergs which is expected to be higher at the shallower Punta Elefante site.

Deschampsia antarctica is a freezing-tolerant plant and the only native Poaceae that grows in the Maritime Antarctic. During the long days of the growing season this plant accumulates sucrose (Suc) in the leaves to 36% of the dry weight. The mechanism that leads to this high accumulation is unknown. The effect of day length and low temperature on sucrose phosphate synthase (SPS) (EC: 2.4.1.14) activity and sugar accumulation was studied in D. antarctica and compared with other Poaceae. Three different day lengths: short (SD) (8/16 h), medium (MD) (16/8 h) and long (LD) (21/3 h); and two temperatures: 4°C (cold-acclimated) and 15°C (non-acclimated) were tested. The highest contents in total soluble sugars (TSS) and Suc were reached in crowns and leaves, respectively, in cold-acclimated plants under LD. TSS and Suc contents and SPS activity with cold acclimation were higher in D. antarctica than in other agricultural (wheat, oat and barley) and non-agricultural (D. caespitosa and D. beringensis) Poaceae species. Suc/TSS ratio was higher in all Deschampsia species than in agricultural Poaceae species. SPS activity and sucrose content in leaves were positively correlated only in LD cold acclimated plants. This result shows that SPS activity is responsive to day length in D. antarctica.