The study of polychaetes from the Marion Dufresne expedition to the Îles Crozet in 1982 provided 45 species from depths ranging from 50–1055 m. The most abundant was Eunice pennata, found at all depths and in all types of substratum in about 66% of the samples. This species with Laetmonice producta, Harmothoe spinosa and Lanice marionensis made up over 50% of all polychaete specimens. A homogenous polychaete assemblage dominated by the above mentioned group of species was encountered in the shallower stations (100–300 m). A mosaic-like and less abundant polychaete fauna with some characteristic, abundant species: Amage sculpta, Laetmonice wyvillei, Leanira quatrefagesi and Melinna cristata was encountered in the deeper stations (300–1055 m). Clear similarities between the polychaete fauna of Îles Crozet and soft-sediment polychaete assemblages of Marion and Prince Edward Islands were noticed. No such affinity was encountered with the polychaete fauna of Îles Kerguelen. Their position in relation to the Polar Front as well as possible differences in bottom deposits (calcareous versus siliceous) may in part explain these dissimilarities. The biogeographical status of Kerguelen Islands is also discussed.

Population growth of the southern giant petrel Macronectes giganteus from South America has been linked with an increase in fishing activities. It was demonstrated recently that a population from Elephant Island, Antarctic Peninsula, largely overlaps its non-breeding distribution with zones of high fishing intensity off South America. This study investigated the assumption that the increase in this population since the 1980s is related to an increase in fisheries off South America. Our results show that the population size is proportional to the increase in demersal and squid fisheries. These fisheries produce a considerable amount of discards, which can be used by non-breeding southern giant petrels as a food source during unfavourable conditions in winter. This may enhance the adult survival rates with potential carry-over effects on population size. Our study shows that we need to further understand the effects of fishery discards/offal on scavenging seabirds of the Southern Ocean, and highlights the importance of understanding the carry-over effects of seabird–fisheries interactions during the non-breeding phase in population dynamics.

Terrestrial palynomorphs from the glaciomarine Pagodroma Group provide the first stratigraphically-constrained record of Cenozoic terrestrial vegetation for the northern Prince Charles Mountains, East Antarctica. In general, contemporaneous spores and pollen are extremely sparse, but palynological assemblages of the late middle–late Miocene Fisher Bench Formation and Battye Glacier Formation have relatively more abundant Cenozoic spores and pollen compared with those of the Oligocene Mount Johnston Formation and the Pliocene–early Pleistocene Bardin Bluffs Formation. Spore-pollen assemblages from the Battye Glacier Formation and the Fisher Bench Formation are dominated by Chenopodipollis, with a few other accessory angiosperm and podocarp pollen, pteridophyte and bryophyte spores, and algal cysts, reflecting a low diversity herb-tundra vegetation and a climate similar to the present-day cool to cold sub-Antarctic regions. Reworked Permian–Triassic miospores in Amery oasis (unofficial name) sediments probably indicate local provenance from the Amery Group but Jurassic–Cretaceous and possible early Cenozoic miospores reflect an unknown source.

Macrofossils discovered in the Battye Glacier Formation (Pagodroma Group) of the Prince Charles Mountains, East Antarctica, provide important insight into marine life of the mid-Tertiary, rarely preserved elsewhere on the continent. Recorded are five species of macroinvertebrates; these are Adamussium n. sp.? cf. colbecki (Smith, 1902) (Bivalvia), Laternula? sp. (Laternulidae), Mytilidae genus and species indeterminate (Bivalvia), Bivalvia genus and species indeterminate, and Polychaeta genus and species indeterminate. Based on stratigraphical data and faunal composition, the clasts are dated as no younger than Early Miocene. This is one of the oldest reports of Adamussium from Antarctica, previously known from the Late Pliocene to Recent with a possible record in the Late Oligocene–Early Miocene. Palaeoecological data and facies analysis indicate that these taxa inhabited a shallow- to mid-shelf marine environment of normal salinity that was oligotrophic. The substrate was a soft, pebbly and sandy bottom that was sufficiently mobile to sponsor deep burrowing forms.

Although most of the notothenioid fishes have geographic distributions restricted to the Southern Ocean, several species with inferred Antarctic origins have come to permanently inhabit the warmer waters around New Zealand and southern South America. However, it remains unknown whether the Antarctic ancestry of these secondarily temperate species continues to influence their modern heat tolerance. We investigated the heat tolerance of one such secondarily temperate nototheniid, Notothenia angustata, which is now endemic to the waters around the South Island of New Zealand. Their heat tolerance was determined using the critical thermal maximum (CTMax) both when acclimatized to their winter water temperatures (7.9°C), and warm acclimated (15°C) near the summer water temperatures in Otago Harbour. When compared to equivalently acclimated specimens of the basal New Zealand notothenioid Bovichtus variegatus, N. angustata have consistently lower CTMaxs, though they are significantly greater than those determined from 10°C acclimated specimens of its endemic Antarctic congener, N. coriiceps. While this shows greater heat tolerance in the secondarily temperate N. angustata than in endemic Antarctic species, it also suggests that some of its ancestral intolerance to heat persists.

This paper reports the dating of apatite fission tracks in eleven rock samples from the South Shetland Archipelago, an island arc located to the north-west of the Antarctic Peninsula. Apatites from Livingston Island were dated as belonging to the Oligocene (25.8 Ma: metasediments, Miers Bluff Formation, Hurd Peninsula) through to the Miocene (18.8 Ma: tonalites, Barnard Point). Those from King George Island were slightly older, belonging to the Early Oligocene (32.5 Ma: granodiorites, Barton Peninsula). Towards the back-arc basin (Bransfield Basin), the apatite appears to be younger. This allows an opening rate of approximately 1.1 km Ma−1 (during the Miocene–Oligocene interval) to be calculated for Bransfield Basin. Optimization of the apatite data suggests cooling to 100 ± 10°C was coeval with the end of the main magmatic event in the South Shetland Arc (Oligocene), and indicates slightly different tectonic-exhumation histories for the different tectonic blocks.

Freshwater drainage systems, fed by melting of nearby inland ice and perennial snowdrifts, exist in the south-eastern part of arid, ice-free, coastal Vestfold Hills. Most important is the complex Druzhby system. Intriguing questions arise about the conditions controlling its seasonal development and about the consequences of possible changes of those conditions. A water-balance was calculated for 1990–91. The system went through four seasonal phases of which only one displayed a fully developed external drainage. Evidently, the relative duration of those phases can vary considerably from one year to another. The system depends critically on the water supply from ice-dammed Chelnok Lake, which could readily be drained by a minor retreat of Sørsdal Glacier. Exposed to excessive evaporation, the large Crooked Lake would then become internally drained and reach a new equilibrium in ∼830 years. A Crooked Lake sediment core can be interpreted as suggesting this occurred during the Holocene. The idea, inferred from striae, of a late Holocene Chelnok Glaciation reaching the northern shores of Crooked Lake is questioned. Instead, it is suggested that the Chelnok striae originate from local basal melting of the ice sheet draining southward into a deglaciated Sørsdal trough. At present, runoff is determined by opposing short and long-term climatic influences.

This study estimates energy and mass balance at the edge of the Antarctic ice sheet close to a non-glaciated area. An automatic weather station was installed on the ice sheet, near an ice free area of Schirmacher Oasis in Dronning Maud Land, East Antarctica. Hourly snow-meteorological parameters were recorded and observed during the summer of the year 2007–08. Hourly radiative and turbulent energy fluxes were estimated at the ice surface. An ultrasonic sensor was used to measure accumulation or ablation at the glacier surface. Ground Penetrating Radar was also used to measure the changes in ice thickness at the observation point. The net radiative flux was the main heat source and the latent heat flux was the main heat sink for the ice sheet with seasonal average values of 98 W m-2 and -86.7 W m-2 respectively. There was a high ablation rate for the ice sheet near the non-glaciated area with a seasonal mean of 0.0172 m w.e. per day. Over the period 10 November 2007–7 February 2008 the mass balance was -1.53 m w.e. Good correlation (r2 = 0.97) was observed between estimated and observed hourly ablation of the glacier. Sublimation and melt processes contributed 16.5% and 83.5% respectively to the net summer ablation.

During the last decade, methods for detecting DNA polymorphisms have proliferated at a bewildering pace. Today the investigator must choose among various types of genetic markers as well as between a variety of methods for discovering and screening polymorphisms. Polymorphisms useful for the analysis of population structure are found in both mitochondrial and nuclear genomes. Marker development may proceed along two routes: 1) discovery of species–specific markers, and 2) application of universal methods. Species-specific markers are based on sequence data from the target species or close relatives, whereas universal markers are based on the use of polymerase chain reaction (PCR) primers targeted to regions highly conserved across diverse taxa. Markers commonly employed include mitochondrial DNA polymorphisms, microsatellites, anonymous nuclear loci and known genes (both coding and noncoding regions). Methods for detecting polymorphisms range from technically simple (RFLP analysis) to more sophisticated mutation scanning methods. We review the application of these approaches to several key Antarctic species (the Patagonian toothfish Dissostichus eleginoides, the mackerel icefish Champsocephalus gunnari, and the squid Martialia hyadesi Rochebrune & Mabille, 1889) and present preliminary data on genetic polymorphisms in toothfish and icefish.

Geographic Information System (GIS) data from southern Alexander Island were used to evaluate valley asymmetry from an area where ground observations had suggested that south facing slopes were steeper than north facing. Using digital elevation modelling (DEM), data were collected from 2° and 10° arcs centred on the four cardinal directions in order to determine average slope angles for a whole nunatak area (Mars Oasis). It was found that south facing slopes were significantly steeper (34°) than the north facing (28°); east and west facing slopes were each 31°. Bedrock in this area is (approximately) horizontally bedded and so valley asymmetry is considered to be due to aspect-influenced periglacial weathering processes.

Dating Jurassic terrestrial floras in the Antarctic Peninsula has proved problematic and controversial. Here U–Pb series dating on detrital zircons from a conglomerate interbedded with fossil plant material provide a maximal depositional age of 144 ± 3 Ma for a presumed Jurassic flora. This is the first confirmed latest Jurassic-earliest Cretaceous flora from the Latady Basin, and represents some of the youngest sedimentation in this basin. The presence of terrestrial sedimentation at Cantrill Nunataks suggests emergence of the arc closer to the Latady Basin margin in the south compared to Larsen Basin in the north, probably as a result of the failure of the southern Weddell Sea to undergo rifting.

We present a high-resolution spatial study of ocean surface carbon dioxide partial pressure (pCO2), temperature and salinity coupled with a seismic survey performed in subpolar waters with a variable presence of glaciers along the coastal margins of Admiralty Bay and the Bransfield Strait, northern Antarctic Peninsula, during the late spring season. Three zones were identified in this bay. The shallow and relatively fresh SHALLOW GLACIER THAW zone in the inner portion of the bay had high freshwater inputs from active glacial meltwater channels, representing higher pCO2 levels (median ~438 μatm) than the shallow and relatively salty SHALLOW zone without glaciers along the margins and dominated by macroalgae communities at the bottom, which showed relatively low pCO2 levels (median ~371 μatm). The deep and relatively salty CENTRE zone was highly influenced by seawater intrusions from the Bransfield Strait, representing intermediate pCO2 levels (median ~397 μatm). The net sea-air CO2 fluxes in late spring obtained from the high-resolution surface survey in Admiralty Bay indicate a condition of near neutral air-sea CO2 flux, with a median (25–75% interquartile range) value of -0.07 mmol m-2 day-1 (ranging from -12.21 to +4.33 mmol m-2 day-1), contrasting with the slight source to the atmosphere estimated from measurements only in the CENTRE zone. This finding suggests that temperature-sensitive metabolic and physical-chemical processes may cause significant variability in the ocean surface distribution of CO2 over short shoreline distances in the northern Antarctic Peninsula.

Despite several works that have documented patterns of diversity in deep sea organisms, trends of diversity and the processes responsible for such trends still remain unclear. To date very few studies have documented the effects of variables such as latitude and longitude in deep-sea organisms in the Antarctic region. We explored the spatial patterns of diversity of benthic gastropods and bivalves in an extensive region about 2200 km long and 500 km wide from the South Shetland Islands to the Bellingshausen Sea in West Antarctica. A total of 134 species from 54 sites was recorded. Alpha diversity and beta diversity (measured as Whittaker’s and Bray-Curtis similarity indices) were highly variable among areas. None of the species richness estimators measured as Sobs, Chao2, Jacknife1 and Jacknife2, stabilized towards asymptotic values in any area. The number of rare species was large with almost half of species represented by 1 or 2 individuals (41%) and most species (62%) restricted to 1 or 2 sites. The partial Mantel test revealed that similarity between sites increased with the decrease of depth differences, but not with horizontal separation.

The community of encrusting and boring organisms developed on shells of the gastropod Antarctodarwinella ellioti from the lower section of the La Meseta Formation (Eocene) exposed on Seymour (Marambio) Island, Antarctic Peninsula, allows inference that the shells were inhabited by hermit crabs. A Chi-square Independence Test revealed that the community - dominated by polychaetes and bryozoans - shows preference for the aperture interior area of the shell. A subsequent Cochran Q Test indicated that the differences in frequency of encrusting and boring organisms as counted on the different interior sectors of the aperture were statistically significant. Thus, polychaetes, boring bryozoans, and encrusting bryozoans, do not show the same frequency in each interior sector of the aperture; they are more frequent on the columella (P < 0.0001, P < 0.01 and P < 0.001 respectively). Encrusting bryozoans also appear to show a preference - albeit not as high as on the columella - for the outer lip. This community of boring and encrusting organisms and their distribution on the shell confirms that the shells were inhabited by hermit crabs. The community is similar to that described in Recent hermitted shells from mid-latitude temperate water environments, suggesting that such communities were already established in the Eocene.

The diet of breeding Antarctic shags (Phalacrocorax bransfieldensis) was investigated at four colonies on the Danco Coast, Antarctic Peninsula, by the analysis of 616 pellets (regurgitated casts) collected from December 1997 to February 1998. Overall, demersal-benthic fish were the most frequent and important prey at all the colonies, followed by octopods and gastropods. Amongst fish, Notothenia coriiceps was the main prey in all of the sampling sites, followed in similar importance by Gobionotothen gibberifrons at Cape Herschel, Primavera Island and Midas Island and in less importance by Harpagifer antarcticus at Py Point. There were marked differences among colonies in the size of the fish consumed. The largest and the smallest specimens were eaten by shags from Midas Island and Py Point respectively. This was mainly influenced by the number of specimens of the smallest fish species, H. antarcticus, consumed at Py Point. The differences in the diet composition may be related to the different foraging areas used by the shags. Results from this study differ from previous studies around the Antarctic Peninsula. The shags at the Danco Coast preyed markedly more intensively than those at the South Shetland Islands on G. gibberifrons. This finding reflects the low abundance of this fish species in inshore waters (< 100 m depth) at the South Shetland Islands and supports the use of the Antarctic shags to monitor trends in local populations of coastal fish species.

Weddell seals are polar predators that must partition their time between many behaviours, including hunting prey at depth and breathing at the surface. Although they have been well studied, little is known about how foraging behaviour changes when access to breathing holes is restricted, such as in the isolated-hole paradigm. The current study took advantage of previously gathered data for seals diving at an isolated hole to compare with foraging behaviour of free-ranging seals that had access to multiple holes. We examined dive structure, hunting tactics, and allocation of time, locomotor activity and energy based on three-dimensional dive profiles and video imagery of prey encounters for two free-ranging and six isolated-hole seals. Midsummer foraging dives of free-ranging seals were remarkably similar to those of seals diving at an isolated hole, but there were differences in two behavioural states and the frequency of several behavioural transitions. Results indicate that seals employ an energetically more conservative foraging strategy when access to breathing holes is limited and prey are less abundant. These results highlight the importance of understanding the complex interactions between breathing hole access, prey abundance and other factors that may result in different Weddell seal foraging strategies under changing future conditions.

Only one living specimen of Adamussium colbecki was found amongst the shells of this species collected in the Lazarev and Weddell Seas, and those of the limpet Nacella cf. concinna from three locations in the southern Weddell Sea. In order to explain this peculiarity four hypotheses are discussed. The possibility that the shells belong to living deep-water populations is in contradiction to the high number of trawl samples taken in the area and the abundance of empty shell material. 14C dates show the shells are recent, thus excluding the possibility that the shells belong to autochthonous fossil populations exposed on the seafloor. Lateral transport of living specimens or shells over long distances by marine currents or by ice is unlikely due to their state of preservation and the water circulation pattern. The most likely explanation is that the shells are allochthonous, transported only over short distances by marine currents from adjacent areas underneath floating ice shelves where both species have living populations.

Pingüinera Stream is one of the two main lotic environments of Cierva Point (Antarctic Specially Protected Area No. 134) on the Danco Coast, Antarctic Peninsula. It originates in a large snowfield, flows through a penguin rookery, moss and grass banks, discharging into Cierva Cove. During late Antarctic summer 2003, we sampled the stream at six locations along its course. Abiotic features characterize it as a clear water system, yet receiving a very high amount of PO4-P and NH4-N from the rookery. These nutrients decrease downstream mainly due to uptake by epilithic algae and oxidation of NH4+ to NO3-, consequently lowering pH and dissolved O2, which was always under-saturated. Strong correlations between all these parameters support these findings. The epilithic algal community shows both temporal and spatial changes in biomass, composition and relative frequencies. Dominant species at the higher reach of the stream are cyanobacteria, mainly Chamaesiphon subglobosus (Rostafinski) Lemm. and a mesh of Leptolyngbya spp. filaments. The chlorophyta Prasiola calophylla (Carmich.) Menegh. dominates the community in oxygenated, fast-flowing reaches. Comparison with the other main stream from Cierva Point, which is not influenced by the rookery, shows that growth and survival of the epilithic community in this area is limited by factors other than nutrient concentrations.

The geographical distribution of the two species of the genus Parachaenichthys is allopatric and restricted to the inner shelves of South Georgia–South Sandwich Islands (P. georgianus) and South Orkney Islands–South Shetland Islands (P. charcoti). To evaluate the consistency between the geographical patterns of adult distribution and early life history traits of P. charcoti, sagittal otoliths were used to estimate growth rate and pelagic duration in larvae and juveniles of this species collected in the Bransfield Strait in winter and summer, respectively. Individual age was determined through microincrement counts, assuming they were daily increments. The Gompertz model was fitted to age–length estimates, providing a mean growth rate of 0.22 mm day-1 estimated for 28–204-day-old individuals. Larval hatching was spread over a relatively wide period, lasting from July throughout September. The pelagic larval duration of P. charcoti was about six months based on ageing data of larvae and juveniles, as reported for P. georgianus from South Georgia. The strong dependence of larvae on the inshore habitat may hamper their dispersal at large spatial scale limiting the connectivity among distant populations, providing clues to interpret the present geographical distribution of the two species.