Most of the species in the Ectemnorhinin are cryptogam feeders, angiosperm feeders representing a minority. It is hypothesized that this dearth of angiosperm feeders is due to previous climatic conditions, which precluded angiosperm herbivory, but allowed for the exploitation of a diverse cryptogamic flora, and that only with the post-glacial warm-up of the Subantarctic has angiosperm herbivory become possible. When examined in the light of the Quaternary history of the South Indian Ocean Province islands, evidence obtained from a study of the habitat use, diet and morphology of species within the tribe supports this hypothesis.

This paper proposes a new objectively-generated vegetation classification for southern and northern Victoria Land (continental Antarctica) based on the floristic composition of the plant communities. The new classification aims to integrate the existing physiognomic classification of the cryptogamic Antarctic tundra, provide useful data on floristic composition and distribution of the vegetation occurring in southern and northern Victoria Land, and develop a suitable tool allowing easy comparison of syntaxa from different locations. Field data from 26 sites along a latitudinal gradient (72°–77°S) were analysed by a hierarchical classification integrated with multivariate statistics, including indirect ecological information (Principal Component Analysis). Similarity of the identified groups was assessed through the Jaccard similarity index. The new classification is compatible with previous ones and is widely applicable to Victoria Land and includes previous classification. This standardized approach relates plant communities to their floristic composition and provides a basis for relating vegetation composition to environmental gradients and to patterns of vegetation dynamics and succession which are still poorly understood in Antarctica.

Macromolecular substances that cause pitting and other modifications of growing ice crystals were found to be associated with cyanobacterial mats, eukaryotic algae and mosses from Ross Island and the McMurdo Dry Valleys, Antarctica. Ice-pitting activities were largely retained by dialysis membranes with molecular weight cut-offs of up to 300 kDa. Unlike most aqueous solutes, the ice-active molecules were not excluded from the ice phase during freezing. The ice-pitting activities of each of the samples tested was destroyed by exposure to temperatures between 45 and 65°C, suggesting that they have a protein component. Ice-active substances were not found in cyanobacteria or mosses from temperate climates, but ice-activity was found to be associated with mosses from cold habitats in North America. Although the function of the ice-active substances is not known, their apparent confinement to cold environments suggests that they have a cryoprotective role.

The summer of 1997 was characterized by unusually large amounts of pack ice in the southeastern Weddell Sea, and less than 10% of the area that is commonly ice-free in summer was open. A modest phytoplankton bloom developed in the upper mixed layer in the northernmost area (72°S). The bloom peaked in mid-February with max chlorophyll concentrations of 1.5 μg l−1, and integrated stocks of 55–60 mg m−2. Autotrophic flagellates dominated the biomass (80–90% of the chlorophyll) at first, while diatoms increased relative to flagellates during the bloom. Nutrient deficits, however, indicated that a much larger biomass was produced than was observed. Freezing starting after mid-February probably terminated the bloom, resulting in a pelagic growth season limited in time (less than two months) and space. The sea ice had a distinct brown layer of algae, usually at 1–2 m depth, with average chlorophyll biomass of 10.3 mg m−2. The ice cover exhibited a substantial amount of ridges, with ice algae growing in cavities and other structures, but with lower biomass than in the bands. Ice algae were also found growing on the lower 2 m of the ice shelf (visible at low tide). The overall growth season in the ice lasted several months, and ice algal production may have exceeded pelagic production in the Weddell Sea during the growth season of 1997. Pennate diatoms, like Fragilariopsis curta and F. cylindrus, dominated both in ice and in open water above the pycnocline, while Phaeocystis antarctica dominated in deeper layers and in crack pools. Euphausiids, particularly young stages, were frequently observed grazing on ice algae in ridges and on all sides of the floes, (confirmed by the gut content). Ice algae would thus have served as an ample food supply for the krill in the summer of 1997.

Although predictions suggest that ocean acidification will significantly impact polar oceans within 20–30 years, there is limited information regarding present-day pH dynamics of the Southern Ocean. Here, we present novel high-frequency observations of pH collected during spring of 2010 using SeaFET pH sensors at three locations under fast sea ice in the southern Ross Sea. During these deployments in McMurdo Sound, baseline pH ranged between 8.019–8.045, with low to moderate overall variation (0.043–0.114 units) on the scale of hours to days. The variation was predominantly in the direction of increased pH relative to baseline observations. Estimates of aragonite saturation state (ΩAr) were > 1 with no observations of subsaturation. Time series records such as these are significant to the Antarctic science community; this information can be leveraged towards framing more environmentally relevant laboratory experiments aimed at assessing the vulnerability of Antarctic species to ocean acidification. In addition, increased spatial and temporal coverage of pH datasets may reveal ecologically significant patterns. Specifically, whether such variation in natural ocean pH dynamics may drive local adaptation to pH variation or provide refugia for populations of marine calcifiers in a future, acidifying ocean.

Of the more than twenty historically active volcanoes in Antarctica and the sub-Antarctic region only two, to our knowledge, host any ground-based monitoring instruments. Moreover, because of their remoteness, most of the volcanoes are seldom visited, thus relegating the monitoring of volcanism in this region almost entirely to satellites. In this study, high temporal resolution satellite data from the Hawaii Institute of Geophysics and Planetology's MODVOLC system using MODIS (Moderate Resolution Imaging Spectroradiometer) are complemented with high spatial resolution data (ASTER, or Advanced Spaceborne Thermal Emission and Reflection Radiometer, and similar sensors) to document volcanic activity throughout the region during the period 2000–10. Five volcanoes were observed in eruption (Mount Erebus, Mount Belinda, Mount Michael, Heard Island and McDonald Island), which were predominantly low-level and effusive in nature. Mount Belinda produced tephra, building a cinder cone in addition to an extensive lava field. Five volcanoes exhibited detectable thermal, and presumed fumarolic, activity (Deception, Zavodovski, Candlemas, Bristol, and Bellingshausen islands). A minor eruption reported at Marion Island was not detected in our survey due to its small size. This study also discovered a new active vent on Mount Michael, tracked dramatic vent enlargement on Heard Island, and provides an improved picture of the morphology of some of the volcanoes.

During two consecutive reconnaissance surveys in 2004 and 2005 and a revisit in 2008, the glaciological and meteorological conditions in the vicinity of the new Belgian Princess Elisabeth Station (71°57′S; 23°20′E) on Utsteinen Ridge were investigated. We set up an automatic weather station, measured the ice thickness around the Utsteinen Ridge, and established a mass balance stake network. These baseline investigations show that Utsteinen Ridge is a relatively sheltered spot from the main katabatic winds. Furthermore, winter temperature conditions are rather mild, confirming the coreless winter conditions of the Antarctic ice sheet. Mass balance is generally low (near zero) with a small accumulation to the east and relatively little ablation to the west of Utsteinen Ridge. Ice flow in the vicinity of the station is also minimal, since the Sør Rondane Mountains upstream of the station block most of the ice flow, a feature that is most apparent in the area where the station is situated. Measurements of the surface topography separated by four years show that the construction of the station seems to have a limited effect on the redistribution of snow around it. In view of the sheltered and safe ice conditions, the area is an ideal place for deploying field activities.

Shelf and slope cryptofauna were sampled at the most northerly shelf environments within the Southern Ocean, Shag Rocks. The area is remarkably rich, with seven phyla, 10 classes, 40 families and 81 species on 0.36 m2 of shelf boulders. A large proportion of genera and species found had not been seen there before, some were new to science and species accumulation curves did not approach an asymptote. Current estimates of benthic diversity are clearly still too low if even well studied locations and depths reveal so much novelty with such little sample effort. Proportions of new species were higher in slope samples showing how little we know of this important depth. Significantly, life was just as rich and, surprisingly, abundant on boulders from continental slope depths. Clearly there are places where the continental slope around Antarctica harbours a wealth of species with potential to resupply the shelf if life was ‘bulldozed’ off it by past ice shelf expansions during glacial maxima. Some species on boulders from 1500 m also occur as shallow as the Antarctic intertidal zone. That this rich fauna was ‘Antarctic’ in character shows the extremes, e.g. sea temperature (> 4°C in summer), that they can adapt to given long enough time periods.

A recent review by Ainley et al. has suggested that recent investigations of the ecological structure and processes of the Southern Ocean have “almost exclusively taken a bottom-up, forcing-by-physical-processes approach relating individual species' population trends to climate change”. We examine this suggestion and conclude that, in fact, there has been considerable research effort into ecosystem interactions over the last 25 years, particularly through research associated with management of the living resources of the Southern Ocean. Future Southern Ocean research will make progress only when integrated studies are planned around well structured hypotheses that incorporate both the physical and biological drivers of ecosystem processes.

Carbon dating of basal peat deposits in Cumberland Bay and Stromness Bay and sediments from a lake in Stromness Bay, South Georgia indicates deglaciation at the very beginning of the Holocene before c. 9500 14C yr BP. This post-dates the deglaciation of one local lake which has been ice-free since at least 15 700 14C yr BP on account of its atypical geomorphological location. The latter indicates the likely presence of floristic refugia on South Georgia during the Last Glacial Maximum from which newly exposed terrestrial and aquatic habitats were rapidly colonized.

This study presents the first analysis of benthic megafauna and habitats from the Sabrina Coast shelf, encompassing a proposed Marine Protected Area. Sea bed imagery indicated an abundant benthic fauna compared to other parts of the Antarctic shelf, dominated by brittle stars, polychaete tubeworms, and a range of other sessile and mobile taxa. The distribution of taxa was related (ρ=0.592, P<0.001) to variations in water depth, latitude, substrate type and phytodetritus. High phytodetritus cover was associated with muddy/sandy sediments and abundant holothurians and amphipods, while harder substrates hosted abundant brachiopods, hard bryozoans, polychaete tubeworms, massive and encrusting sponges, and sea whips. Brittle stars, irregular urchins and anemones were ubiquitous. Variations in substrate largely reflected the distribution of dropstones, creating fine-scale habitat heterogeneity. Several taxa were found only on hard substrates, and their broad regional distribution indicated that the density of dropstones was sufficient for most sessile invertebrates to disperse across the region. The hexactinellid sponge Anoxycalyx joubini and branching hydrocorals exhibited a more restricted distribution, probably related to water depth and limited dispersal capability, respectively. Dropstones were associated with significant increases in taxa diversity, abundance and biological cover, enhancing the overall diversity and biomass of this ecosystem.

In January to March 1997, a RV Polarstern cruise that transected the Weddell Sea resulted in samples being taken in thick pack ice in the south-eastern Weddell Sea and then along the marginal ice edge towards the Antarctic Peninsula. Several ice types were thus sampled over a wide geographic area during late summer/early autumn. Common features of the first warm period was the occurrence of surface ponds, and that many floes had quasi-continuous horizontal gaps, underlying a layer of ice and metamorphic snow. With the onset of cold air temperatures in late February the gaps rapidly refroze. The calanoid copepod Stephos longipes occurred in all habitats encountered and showed highest numbers in the surface ice in summer, in the gap water during both seasons and in the refrozen gap water in autumn. Nauplii outnumbered copepodids in the surface ice and refrozen gap water, while in the gap water copepodids, mainly stages CI–CIII in summer and CII–CIV in autumn, comprised about 70% of the total population. The harpacticoid species Drescheriella glacialis did not occur in all habitats and was missing in surface ponds and new ice. Nauplii of D. glacialis were rarely found in gap water, but predominated in the refrozen gaps.

The results of underwater observations and sampling of krill (Euphausia superba) in the western Weddell Sea during the joint Russian-USA Ice Station Weddell-1 Expedition (11 February–9 June 1992) are presented. Krill was sampled from the same large ice floe composed of both 1- and 2-year ice as it drifted northward for a distance of c. 700 km. Abundance estimates for krill under this floe were in the range 0.1–6.25 ind m−2. Krill aggregate in areas where rafting of ice floes and formation of new ice occur, or around a protected diving hole. The krill sampled consisted mainly of furcilia 6 and post-larvae which did not belong to the 0+ group originating in this (1991–92) year, but presumably hatched in the summer season of 1990–91 and developed very slowly so that at the end of the following summer season, larval stages were still present in the population. No increase of the mean krill size was observed during 2.5 months of observation. The role of larval advection for the maintenance of krill population in the Weddell Sea is discussed.

The climatic and sea ice conditions of the Southern Ocean are highly variable within and between years, and a better understanding of the influence of climatic conditions on the various parts of the marine food chain is needed. This paper summarizes data on breeding success of a krill-dependent predator, the Wilson's storm petrel Oceanites oceanicus, in a colony on King George Island, South Shetland Islands, Antarctica, over four breeding seasons from 1995/1996 to 1999/2000. The seasons differed greatly in environmental conditions and in the resulting food availability which was reflected in inter- and intra-annual variations in feeding frequency. The breeding success was consequently variable. Starvation, the main cause of chick mortality in three out of four breeding seasons was associated with reduced sea ice cover in winter, which is known to depress food availability in the following breeding season. Food delivery rates also depended on the prevailing winds, which drive the transport of zooplankton-rich water masses. Snowstorms caused additional chick mortality in two out of four seasons when nest burrows became blocked. Implications for the use of Wilson's storm petrels for monitoring of krill are considered.

Variations of metal concentrations with body size were investigated in kidney, digestive gland and gill of the Antarctic clam, Laternula elliptica, collected from a near-shore habitat at King George Island. Positive relationships for metal concentrations with body size were common among the three organs for most of the metals, while an inverse relationship was found only in the digestive gland for Cu, Zn and Mn. In the gill, concentrations of eight out of the ten metals increased linearly with body size, whilst in the kidney concentrations of Cd, Zn, Pb, Co and Ni were best fitted by quadratic regression curves, viz. increasing continuously until reaching a peak at around an 80 mm shell length. This may reflect specific regulatory activities for the extremely high accumulation of these metals in the kidney, particularly Cd (28–354 μg g−1 tissue dry weight). The overall prevalence of positive relationships indicate net accumulation of these metals throughout life, which may be at least in part associated with the slow growth and long life span of this cold-water bivalve species. The study demonstrates distinct body size-metal concentration relationships in the three organs of L. elliptica, and suggests they may be useful as biomonitors for assessing changes in metal concentrations in Antarctic waters.

Microscopy, DNA sequencing, and amplified fragment length polymorphism (AFLP) were used to examine variation within Nostoc commune from collections between 72 and 78°S in Victoria Land, Antarctica. Although there is considerable bias of collected material towards southern latitudes, and this material varies greatly in age (collected between 1984 and 2004), an important new phylogeographic pattern was found. DNA sequencing of the tRNAleu(UAA) region, used recently to define form species N. commune, revealed little variation between collections. AFLP analysis, however, split the collected material according to habitat (irrigated soil communities versus ponds), rather than latitude. These results suggest that environmental factors linked to latitude are not the greatest drivers of genetic variation in Victoria Land. These may operate at a lower level but would require intensive sampling within narrowly defined habitat types at a range of latitudes to uncover. We advocate extensive sampling across local environmental gradients based on water availability, comparative culturing, and development of sequence characterised amplified regions (SCARs) across a range of latitudes in future seasons of the Latitudinal Gradient Project.

Most Antarctic bivalves are small and protect their young by holding fertilized eggs or larvae in their mantle cavities for varying periods. Nourishment for these early growth stages is provided by yolk reserves rather than by planktotrophy. The anomalously large Antarctic scallop, Adamussium colbecki, has unprotected planktotrophic larvae that are spawned during the austral spring. Successful recruitment of these larvae, in populations which are most abundant in oligotrophic habitats, may be associated with episodic pulses of organic material. Reasons why planktotrophy persists in A. colbecki are suggested by a comparison with another large Antarctic bivalve, Laternula elliptica. The latter has protected lecithotrophic larvae that are released at the beginning of the austral winter. This comparison suggests that unprotected larval development persists in A. colbecki because of unusual anatomical and ecological adaptations among the adults of the Adamussium lineage that have been evolving in the Southern Ocean since the early Oligocene.

The various life history stages of the Weddell Sea population of Pleuragramma antarcticum were sampled to investigate life-history patterns of this ecologically important polar fish. Otoliths were examined for size, morphology and microstructure. Age determination of Antarctic fishes has proved to be difficult because of small ambient temperature fluctuations. External and internal examination of otoliths by scanning electron microscopy revealed internal increments (assumed to be daily) and hatching marks. Back calculation of hatching dates from otolith increments, suggested a hatching season from September-November, with recruitment to the adult population at three to five years of age. Growth data conformed well to the von Bertalanffy equation. Fish grew slowly, with the largest fish attaining ages of more than 30 years. A multivariate mathematical model relating age to otolith morphometrics and fish size proved reliable, making it possible to age large sample sizes of fish. Limited elemental microprobe data obtained from two otoliths demonstrated patterns which may be useful in indicating the environmental life history of individual fish. These collective data suggest that the ecological importance of populations of Pleuragramma antarcticum is most likely due to a long life span and high lifetime reproduction rate.

The diet of breeding white-chinned petrels was studied during the summers of 1996 and 1998 at South Georgia. Krill abundance/availability was high throughout 1996 but apparently low at the beginning of the 1998 breeding season. The diet of white-chinned petrels was similar between years and consistent with previous studies. Krill Euphausia superba (41–42% by weight) was the single most important prey item followed by fish (39–29%) and squid (19–25%). Meal mass was consistent (110 g in 1996, 119 g in 1998) between years but a significant decrease (46%) in feeding frequency in 1998 (0.54 meals day−1 compared to 0.75 meals day−1 in 1996) resulted in 19% less food delivered to chicks in 1998 than in 1996. Breeding success, however, was consistent between years at 44% and similar to that recorded previously at Bird Island. This is in contrast to black-browed and grey-headed albatrosses, both of which experienced almost total breeding failure in 1998. It is suggested that their varied and versatile feeding methods, together with their greater diving ability, capacity to feed at night and extensive foraging range, help white-chinned petrels minimise the effects of krill shortage.

Signy Island has experienced a dramatic increase in fur seal numbers over recent decades, which has led to the devastation of lowland terrestrial vegetation, with the eradication of moss turfs and carpets being the most prominent feature. Here we demonstrate that fur seals also affect the other major component of this region’s typical cryptogamic vegetation, the lichens, although with a lower decrease in variability and abundance than for bryophytes. Classification (UPGMA) and ordination (Principal Coordinate Analysis) of vegetation data highlight differences in composition and abundance of lichen communities between areas invaded by fur seals and contiguous areas protected from these animals. Multivariate analysis relating lichen communities to environmental parameters, including animal abundance and soil chemistry (Canonical Correspondence Analysis), suggests that fur seal trampling results in the destruction of muscicolous-terricolous lichens, including several cosmopolitan and bipolar fruticose species. In addition, animal excretion favours an increase in nitrophilous crustose species, a group which typically characterizes areas influenced by seabirds and includes several Antarctic endemics. The potential effect of such animal-driven changes in vegetation on the fragile terrestrial ecosystem (e.g. through modification of the ground surface temperature) confirms the importance of indirect environmental processes in Antarctica.