The structure and function of swimming muscles in Antarctic fish is reviewed, the emphasis being on the highly endemic sub-order Notothenioidei. Adult stages of the vast majority of species swim at low speeds using large pectoral fins (labriform locomotion). This is supplemented with sub-carangiform swimming in pelagic juvenile stages and in the adult stages of some other species. The thrust for sustained activity is provided by the recruitment of slow muscle fibres. Slow muscle myofibrils typically occur in columns one fibril thick entirely surrounded by mitochondria. The resulting high volume density of mitochondria (30–60%), and short inter-mitochondrial spacing, is thought to represent an adaptation which serves to compensate for the detrimental effects of low temperature on enzyme reaction and diffusion rates. Sub-carangiform swimming is used to achieve burst speeds associated with prey capture and/or predator avoidance. Burst speeds require the recruitment of fast twitch fibres in the myotomes. In many demersal species the energy supply for burst swimming largely comes from phosphogen hydrolysis, and the capacity of fast twitch fibres for anaerobic glycogenolysis is severely reduced. Antarctic fish are characterized by delayed maturation, slow growth and low metabolic rates. The fast myotomal muscles of adult stages often contain few fibres less than 80 μm diameter, fibres 200–450 μm diameter forming the major size class in numerous species. It is therefore likely that hyperplasia ceases at a relatively early stage in development and that subsequent muscle growth involves hypertrophy of existing fibres. Studies of the contractile properties of isolated muscle fibres suggest that low temperature limits maximum swimming performance in Antarctic fish. Kinematic data suggest that this is most noticeable for juvenile stages, which have higher maximum tail-beat frequencies than adults.

Satellite imagery is used to show that the world's second largest emperor penguin colony, at Halley Bay, has suffered three years of almost total breeding failure. Although, like all emperor colonies, there has been large inter-annual variability in the breeding success at this site, the prolonged period of failure is unprecedented in the historical record. The observed events followed the early breakup of the fast ice in the ice creeks that the birds habitually used for breeding. The initial breakup was associated with a particularly stormy period in September 2015, which corresponded with the strongest El Niño in over 60 years, strong winds, and a record low sea-ice year locally. Conditions have not recovered in the two years since. Meanwhile, during the same three-year period, the nearby Dawson-Lambton colony, 55 km to the south, has seen a more than tenfold increase in penguin numbers. The authors associate this with immigration from the birds previously breeding at Halley Bay. Studying this ‘tale of two cities’ provides valuable information relevant to modelling penguin movement under future climate change scenarios.

Megafloral remains recovered from the Jetty Member and the upper part of the Flagstone Bench Formation, Amery Group include Dicroidium and Pagiophyllum. Dicroidium zuberi and D. crassinervis forma stelznerianum occur with Pteruchus dubius and support a Mid to Late Triassic age. A new species of conifer, Pagiophyllum papillatus, is recognized along with an undetermined conifer pollen cone.

The spiny plunder-fish, Harpagifer antarcticus, is a common shallow-water demersal species distributed along the southern limb of the Scotia Arc. A year round study was made of its reproductive biology at Signy Island, South Orkney Islands, for comparison with populations from the Antarctic Peninsula and with H. georgianus at South Georgia. Adult H. antarcticus inhabit rubble substrata and spawn 300–1500 eggs into a nest during May/July. The nest is guarded by both male and female fish during an incubation period of up to 150 days. After hatching during November/December the larvae grow at a rate of 0.082 mm d−1 (summer), 0.049 mm d−1 (winter) and 0.067 mm d−1 (annual), calculated from a time-series of samples collected from the field. This rate of growth is slow even among Antarctic species but is similar to the closely related species H. georgianus. Adult male and female H. antarcticus at the South Orkney Islands attain a maximum standard length of 88 mm and 85 mm respectively.

We report and describe two new small diamictite outcrops on Isla Marambio (Seymour Island), Antarctic Peninsula. These rocks rest on an erosional unconformity on top of the Eocene La Meseta Formation and are unconformably covered by glaciomarine rocks of the ?Pliocene–Pleistocene Weddell Sea Formation. The lithology, fossil content and isotopic ages obtained strongly suggest that the rocks belong to the Hobbs Glacier Formation and support a Late Miocene age for this unit. Additionally, the dated basalt clast provides the oldest age (12.4 Ma) for the James Ross Island Volcanic Group recorded up to now. The here described diamictite cannot be confidently correlated with a glaciomarine unit previously assigned to the Late Eocene–Lower Oligocene taken as proof that initial expansion of ice on Antarctica encompassed the entire continent synchronously in the earliest Oligocene. However, it is now evident that there are likely to be more, short but important, stratigraphic sequences of key regional and Antarctic wide interest preserved on the plateau of Isla Marambio.

Solidified stomach oil deposits in snow petrel colonies in the Antarctic proved to be suitable for 14C dating and provide important palaeobiogeographical and palaeoenvironmental information. Following earlier studies in the Untersee oasis (Central Dronning Maud Land) we present here 14C measurements on comparable deposits from the Bunger Hills (66°10′S, 101°E). The conventional 14C age of the basal layer reflects the occupation age of any particular nesting site and therefore a minimum age for the time when this area became ice-free. According to the 14C results the occupation of the southern part of the Bunger Hills by petrels started about 10000yr ago. The breeding colonies expanded continuously following local ice retreat. The most intensive phases of colonization seem to have been from 8–6 kyr BP and during the past 2 kyr.

Marinobacter sp. W1-16 from Antarctic surface seawater was analysed for the production of extracellular polymeric substances (EPSs). Enhancement of the EPS biosynthesis was carried out by evaluating the influences of the carbon source (type and concentration), temperature, pH and salinity. EPS yields varied strongly depending on sugar substrate and temperature, while pH and salinity did not strongly affect levels of EPS production. Marinobacter sp. W1-16 produced the highest quantity of EPSs when growing at 15°C and pH 8, in the presence of 2% glucose and 3% NaCl. The EPS chemical characterization revealed a molecular weight of about 260 kDa. Colorimetric assays determined a higher quantity of carbohydrate than of proteins and uronic acids, as well as the presence of sulphate, in the extracted EPSs. The monosaccharidic composition resulted in Glc:Man:Gal:GalN:GalA:GlcA in relative molar proportions of 1:0.9:0.2:0.1:0.1:0.01. Some biotechnological potentialities (i.e. emulsifying and cryoprotective actions, and heavy metal binding properties) of the EPSs were proved, suggesting possible industrial and bioremediation applications.

Raised beach ridges on Livingston Island of the South Shetland Islands display variations in both quantity and source of ice rafted detritus (IRD) received over time. Whereas the modern beach exhibits little IRD, all of which is of local origin, the next highest beach (∼250 14C yr BP) has large amounts, some of which comes from as far away as the Antarctic Peninsula. Significant quantities of IRD also were deposited ∼1750 14C yr BP. Both time periods coincide with generally cooler regional conditions and, at least in the case of the ∼250 yr old beach, local glacial advance. We suggest that the increases in ice rafting may reflect periods of greater glacial activity, altered ocean circulation, and/or greater iceberg preservation during the late Holocene. Limited IRD and lack of far-travelled erratics on the modern beach are both consistent with the ongoing warming trend in the Antarctic Peninsula region.

Well-preserved eclogites were found for the first time in Antarctica, at the Lanterman Range, northern Victoria Land. They are part of a mafic–ultramafic belt that lies between the Wilson Terrane, representing part of the palaeo-Pacific margin of Gondwana, and the Bowers Terrane, a Cambro-Ordovician volcanic are and related sediments, accreted to the margin during the Ross Orogeny. The eclogites formed at temperatures in the range 750–850°C and pressures above 15 kbar and subsequently experienced a decompressional path to low pressure amphibolite facies conditions. The formation and exhumation of eclogites and the attainment of the metamorphic peak in adjacent rock units is consistent with a plate convergent setting model at the palaeo-Pacific margin of Gondwana.

Deception Island is the largest volcano in the actively extending Bransfield Basin, a marginal basin situated behind the extinct South Shetland Islands arc. Deception Island has been well studied but its submerged flanks have not. A multibeam bathymetry survey was conducted around the island in 2005. Data from the flooded caldera show no evidence for recent localized resurgence. The gently-sloped bottom of the caldera basin is consistent with either a broad zone of resurgence on its east side associated with trap door deformation or with higher rates of sediment supply from the east side of the island. Around the island, numerous tectonic and volcanic features on the volcano's east and west flanks are nearly all aligned with the regional strike (~060°) of the Bransfield rift and there is very little evidence for the other fault populations that have been identified on the island. We infer that models that link the ongoing tectonic development of Deception Island to complex regional tectonics are less likely than models in which the dominant regional extension in Bransfield Strait is modulated by the local effects of caldera collapse and possibly a small right-lateral transfer zone offsetting the primary extension axes in the Central and Western Bransfield Basins.

To survive in Antarctica, early explorers of Antarctica's Heroic Age erected wooden buildings and brought in large quantities of supplies. The introduction of wood and other organic materials may have provided new nutrient sources for fungi that were indigenous to Antarctica or were brought in with the materials. From 30 samples taken from Discovery Hut, 156 filamentous fungi were isolated on selective media. Of these, 108 were screened for hydrolytic activity on carboxymethyl cellulose, of which 29 demonstrated activities. Endo-1, 4-β-glucanase activity was confirmed in the extracellular supernatant from seven isolates when grown at 4°C, and also when they were grown at 15°C. Cladosporium oxysporum and Geomyces sp. were shown to grow on a variety of synthetic cellulose substrates and to use cellulose as a nutrient source at temperate and cold temperatures. The research findings from the present study demonstrate that Antarctic filamentous fungi isolated from a variety of substrates (wood, straw, and food stuffs) are capable of cellulose degradation and can grow well at low temperatures.

Lake sediment cores from Midge Lake, Livingston Island, South Shetland Islands and Sombre Lake, Signy Island, South Orkney Islands were analysed for volcanic tephra using light microscopy and magnetic susceptibility. Cores were dated using published 14C and 210Pb chronologies. Electron probe microanalyses of discrete tephra glass shards were undertaken to characterise the tephra geochemically in order to identify possible source volcanoes and refine tephrochronological data for the region. Results identified five tephra horizons in a core from Midge Lake. Four of these tephra at 3–4 cm, 8–9 cm (c. 450 yr BP), 15–16 cm (c. 755 ± 105 yr BP) and 21–22 cm (c. 1340 ± 100 yr BP) consisted of sodic basaltic to basalticandesitic glasses, containing abundant labradoritic feldspar inclusions, and a single ‘acidic’ tephra was found at 2–3 cm. Seven tephra horizons were identified in the Sombre Lake core including three basaltic tephra at 3–9 cm (30 ± 4 yr BP to 125 ± 25 yr BP), 31–32 cm and 44–46 cm (1325 ± 50 14C yr BP) and four acidic tephra at 21–22 cm and 24–25 cm, 33–36 cm (c. 1021 14C yr BP) and 54–56 cm (c. 1450 14C yr BP). These are the first tephra to be identified from the South Orkney Islands. Geochemical and grain size analysis indicated that the analysed Midge Lake tephra were derived from the Quaternary Deception Island volcano. Smaller grain sizes, congruent geochemical data and prevailing wind directions also indicate this volcano as the likely source of Sombre Lake tephra. Results highlight the importance of establishing geochemical consistency between tephra deposited across wide geographical areas, during apparently synchronous time periods, if they are to be used in a regional tephrochronology.

We have determined the base composition (percentage of guanine-cytosine base pairs, GC%) of total DNA from Euphausia superba to be 32% ± 0.5%. This is the lowest GC% recorded for a metazoan. Low GC% DNA has high concentrations of thymine (T) residues and consequently a greater abundance of adjacent T residues [T(n) arrays]. Ultraviolet B (280–320 nm, UV-B) radiation damages DNA primarily at (T)n arrays, so we suggest that krill DNA may be more susceptible to damage from increased levels of UV-B radiation over the Southern Ocean than the DNA of other Antarctic organisms.

The emperor penguin (Aptenodytes forsteri) is extremely dependent on the extent and stability of sea ice, which may make the species particularly susceptible to environmental change. In order to appraise the stability of the emperor penguin populations at six colonies in the western Ross Sea, we used linear regression analysis to evaluate chick abundance trends (1983–2005) and Pearson's r correlation to assess their relation to two local and two large-scale climate variables. We detected only one significant abundance trend; the Cape Roget colony increased from 1983 to 1996 (n = 6). Higher coefficients of variation in chick abundances at smaller colonies (Cape Crozier, Beaufort Island, Franklin Island) suggest that such colonies occupy marginal habitat, and are more susceptible to environmental change. We determined chick abundance to be most often correlated with local Ross Sea climate variables (sea ice extent and sea surface temperature), but not in consistent patterns across the colonies. We propose that chick abundance is most impacted by fine scale sea ice extent and local weather events, which are best evaluated by on-site assessments. We did not find sufficient evidence to reject the hypothesis that the overall emperor penguin population in the Ross Sea was stable during this period.

Evidence for one late Eocene and four middle Oligocene eruptions of Mount Petras, Marie Byrd Land provides new insights into reconstructions of middle Tertiary ice sheet configurations, surface topography, and volcanism in West Antarctica. The interpretation presented here of the volcanic record at Mount Petras, based on detailed analyses of lithofacies, petrography, 40Ar/39Ar geochronology, and geochemistry, is significantly different from previous interpretations based on reconnaissance studies. A massive, 25 m thick, mugearite lava near the summit of Mount Petras is 40Ar/39Ar dated to 36.11 ± 0.22 Ma (2 σ uncertainty), indicating an onset of Cenozoic alkaline volcanism in the Marie Byrd Land Volcanic Province in latest Eocene time. Middle Oligocene (29-27 Ma) hawaiite volcaniclastic lithofacies at Mount Petras are interpreted as products of mixed magmatic (Strombolian style) and phreatomagmatic (Surtseyan style) subaerial eruptions. The four hawaiite outcrop areas exhibit characteristics of near-vent tuff cone environments. The near-vent deposits are located at different elevations and positions on Mount Petras and suggest four separate eruptive centres, with eruptions dated to between 28.59 ± 0.22 Ma and 27.18 ± 0.23 Ma. The mixed Surtseyan and Strombolian eruptions imply local or intermittent contact with external water, which we infer was derived from melting of a thin, local ice cap or ice and snow on slopes. The 29-27 Ma volcanic deposits at Mount Petras provide the oldest terrestrial evidence for glacial ice in Marie Byrd Land. The 29-27 Ma tuff cone deposits overlie an erosional unconformity, with > 400 m of topographic relief. The relatively high relief pre-volcanic environment is suggestive of ongoing erosion and is inconsistent with previous interpretations of a regional, low relief, early Cenozoic West Antarctic Erosion Surface.

One of the major issues in (palaeo-) climatology is the response of Antarctic ice sheets to global climate changes. Antarctic ice volume has varied in the past but the extent and timing of these fluctuations are not well known. In this study, we address the question of amplitude and timing of past Antarctic ice level changes by surface exposure dating using in situ produced cosmogenic nuclides (10Be and 21Ne). The study area lies in the Ricker Hills, a nunatak at the boundary of the East Antarctic Ice Sheet in southern Victoria Land. By determining exposure ages of erratic boulders from glacial drifts we directly date East Antarctic Ice Sheet variations. Erosion-corrected neon and beryllium exposure ages indicate that a major ice advance reaching elevations of about 500 m above present ice levels occurred between 1.125 and 1.375 million years before present. Subsequent ice fluctuations were of lesser extent but timing is difficult as all erratic boulders from related deposits show complex exposure histories. Sample-specific erosion rates were on the order of 20–45 cm Ma-1 for a quartzite and 10–65 cm Ma-1 for a sandstone boulder and imply that the modern cold, arid climate has persisted since at least the early Pleistocene.

Possible effects of “El Niño” Southern Oscillation (ENSO) components “El Niño”and “La Niña“ on populations of southern elephant seals, Mirounga leonina L., are considered in this study. Information on pup weaning mass, collected at King George Island, South Shetland Islands, over a ten-year period (1985–94) was analysed with respect to the occurrence of ENSO and recent research in feeding ecology of this population in the Bellinghausen Sea. Weaning mass of elephant seals was found to be higher during “La Niña” and a lower during “El Niño”. Differences in weaning mass between sexes varied in different proportions during El Niño and La Niña. The teleconnection between tropical Pacific anomalies and the Bellinghausen Sea deserves further research, and our results suggest a way to study this phenomenon using data of elephant seal pups weaning mass as indicators of changes in food availability.

The vertical distribution, abundance, population structure and life cycle of the ice-associated copepod, Paralabidocera antarctica was studied in the fast ice near Syowa Station (69°00'S, 39°35'E) in the eastern part of Lützow-Holm Bay in 1970, 1975 and 1982. The results indicated that P. antarctica inhabited the ice-seawater interface throughout the year with a one year life cycle and was actually present in the sea ice for most of the year except the summer. P. antarctica overwintered as naupliar stages (NIV-NV) with slow development in sea ice during winter. P. antarctica population then developed rapidly and attained adulthood in the water just beneath the sea ice during spring-summer. P. antarctica depended entirely on ice algae for food throughout its whole life-span, suggesting that the ice-seawater interface provides favourable food conditions for P. antarctica. The slow development in naupliar stages in sea ice and short copepodite life span in the water suggest that P. antarctica may adapt its growth strategy to suit the varying fast ice/water interface environment.

The consumption of Antarctic krill (Euphausia superba) by an “average-sized” (male 6994 kg; female 8249 kg), sexually mature Minke whale (Balaenoptera acutorostrata) was estimated, from stomach capacity, ingestion rate and respiratory allometry methods. Estimates obtained from the stomach capacity and respiratory allometry methods differed by 17%–23%. An “average-sized” male Minke whale consumes 37.2 t of krill during a 90-day stay, and an “average-sized” female Minke whale consumes 56.2 t of krill during a 120-day stay, in Antarctic waters during the austral summer. It is estimated that the Minke whale population in the Antarctic (60°S and higher) consumes 35.5 × 106 t of krill annually.