Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.

Hydrocarbons in the environment occur as complex mixtures. The detection of low-level anthropogenic contamination can be difficult as many of the compounds can also be found in biogenic materials. Results obtained in the Antarctic show that accepted methods of distinguishing biogenic from contaminating hydrocarbons are inconsistent. The samples taken from South Georgia in the vicinity of derelict whaling stations had odd-to-even carbon number ratios in the range 0.8–1.0. An offshore site had the highest levels for phytane and the lowest for pristane. The pristane-to-phytane ratio varied between 0.4 and 1.4 and contradicted the interpretation of the odd-to-even ratio at several sites. A value of less than 1.0 for these ratios has been taken to indicate anthropogenic origin. A number of polycyclic aromatic hydrocarbons were detected at all the sites, but the concentration gradient did not correspond with that of the n-alkanes. It is therefore recommended that recognition of anthropogenic input is based on quantification of all compounds against a well-defined baseline. The source of the pollution can then be estimated from the distribution patters of the hydrocarbons.

Livingston Island contains several, distinctive sedimentary and volcanic sequences, which document the history and evolution of an important part of the South Shetland Islands magmatic arc. The turbiditic, late Palaeozoic–early Mesozoic Miers Bluff Formation (MBF) is divided into the Johnsons Dock and Napier Peak members, which may represent sedimentation in upper and lower mid-fan settings, respectively, prior to pre-late Jurassic polyphase deformation (dominated by open folding). The Moores Peak breccias are formed largely of coarse clasts reworked from the MBF. The breccias may be part of the MBF, a separate unit, or part of the Mount Bowles Formation. The structural position is similar to the terrigenous Lower Jurassic Botany Bay Group in the northern Antarctic Peninsula, but the precise stratigraphical relationships and age are unknown. The (?) Cretaceous Mount Bowles Formation is largely volcanic. Detritus in the volcaniclastic rocks was formed mainly during phreatomagmatic eruptions and redeposited by debris flows (lahars), whereas rare sandstone interbeds are arkosic and reflect a local provenance rooted in the MBF. The Pleistocene–Recent Inott Point Formation is dominated by multiple, basaltic tuff cone relicts in which distinctive vent and flank sequences are recognized. The geographical distribution of the Edinburgh Hill Formation is closely associated with faults, which may have been reactivated as dip-slip structures during Late Cenozoic extension (arc splitting).

Penguin blood samples collected at Bird Island, sub-Antarctic South Georgia, and faecal samples taken from penguins at several localities along the Antarctic Peninsula were analysed in order to investigate if influenza A virus is present in penguin populations in the South Atlantic Antarctic region. Serology was performed on the blood samples while the faecal samples were screened by a RT-PCR method directed at the matrix protein gene for determining the presence of influenza A virus. All faecal samples were negative by PCR, but the blood samples gave serologic indications that influenza A virus is present amongst these penguin species, confirming previous studies, although the virus has still not been isolated from any bird in the Antarctic region.

A net sampling survey was carried out for krill in a standard station grid around Elephant Island during 27 January to 4 February 2001. In comparison with recent years the station grid was extended south, where a large proportion of small size classes, one-year-old juvenile krill was found. Results show a spatial separation of the juvenile krill and the spawning stock, Krill density was significantly higher than during the past years (229 krill 1000 m−3 or 13.0 g m−2). The proportional recruitment index for the entire survey area for the 1999/2000 year class was R1 = 0.573, which is among the highest values recorded during the past 20 years. The maturation index (based on the proportion of gravid stages) was G = 0.99, indicating an early initiation of the spawning season. The results indicate a turning point after a succession of years with poor recruitment success and low stock biomass. This is thought to be the first step for a successful spawning event and a later potential recruitment success of the 2000/01 year-class. The spatial extent of the station grid is discussed in the light of a representative coverage of the stock and the estimated recruitment index.

In the present study the biodiversity of the most abundant phototrophic organisms forming biological soil crust communities were determined, which included green algae, diatoms, yellow-green algae and lichens in samples collected on Ardley and King George islands, Maritime Antarctic. The species were identified by their morphology using light microscopy, and for lichen identification thin layer chromatography as also used to separate specific secondary metabolites. Several sources of information were summarized in an algae catalogue. The results revealed a high species-richness in Antarctic soil crust communities with 127 species in total. Of which, 106 taxa belonged to algae (41 Chlorophyta, nine Streptophyta, 56 Heterokontophyta) and 21 to lichens in 13 genera. Moreover, soil crust communities with different species compositions were determined for the various sampling locations, which might reflect microclimatic and pedological gradients.

Twenty-three juvenile (8–14 months of age) southern elephant seals (Mirounga leonina L.) from Macquarie Island were tracked during 1993 and 1995. Migratory tracks and ocean areas with concentrated activity, presumed to be foraging grounds, were established from location data gathered by attached geolocation-time depth recorders. The seals ranged widely (811–3258 km) and foraging activity centred on oceanographic frontal systems, especially the Antarctic Polar Front and bathymetric features such as the Campbell Plateau region. The seals spent 58.6% of their sea time within managed fishery areas while the remainder was spent on the high seas, an area of unregulated fishing. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) areas 58.4.1, 88.2 and especially 88.1 were important and distant foraging areas for these juvenile elephant seals. From fisheries records, diet and the foraging ecology studies of the seals there appears to be little, if any, overlap or conflict between the seals and commercial fishing operations within the regulated commercial areas. However, attention is drawn to the possibility of future interactions if Southern Ocean fisheries expand or new ones commence.

A limited sampling campaign on the main island of Îles Kerguelen revealed 170 freshwater diatom taxa, belonging to 29 genera. Four different communities were distinguished in two major groups, being determined principally by habitat type. The Fragilaria vaucheriae–Fragilaria germainii assemblage occurs exclusively in running waters. The three other communities, observed in standing waterbodies, are separated by their geographical position on the island with the Fragilaria exigua–Aulacoseira alpigena and the Fragilaria exigua–Fragilaria vaucheriae assemblages, mainly found in the Lac Studer area and the Fragilaria pinnata var. pinnata assemblage, recorded near the coastal line and the research station. Analysis of different waterbody types revealed the habitat preference of the various diatom taxa and identified a diatom flora for running waters and one preferring stagnant waterbodies.

A 2.7 m thick mid-Holocene sedimentary succession composed of alluvial fan and marine beach deposits is exposed at 14.4–17.1 m above sea level (a.s.l.) on the south-eastern coast of Potter Peninsula, King George Island (South Shetland Islands, Antarctica). The raised marine beach deposits contain a subfossil assemblage that includes remains of Adélie (Pygoscelis adeliae) and gentoo (P. papua) penguins, skua (Catharacta sp), seals (elephant seal Mirounga sp), and seaweed fragments. The palaeontological and palaeogeographical evidence allows us to infer that penguin rookeries were active on high cliffs of the Potter Peninsula during the marine beach sedimentation, which is dated to c. 4540–4450 reservoir-corrected 14C yr BP on the basis of radiocarbon dating on penguin bones. The data presented in this paper are in agreement with the Holocene palaeoenvironmental chronology known from Potter Peninsula, and suggest that marine birds and seals inhabited the coastal areas of King George Island probably during a mid-Holocene period of seasonally open marine conditions, which may coincide with a cooling period around Antarctica estimated from ice core records between 8000–4000 yr BP that preceded the “climate optimum” in the Antarctic Peninsula (4000–3000 yr BP).

Concentrations of major ions (Cl−, NO3−, SO42−, Na+, K+, Mg2+, Ca2+) were measured in melting snow and water samples from streams and lakes in ice-free areas throughout northern Victoria Land. Most ions in snow and terrestrial water derive from the marine environment and their concentrations are extremely variable in space and time, especially in water systems without melting snow and ice. The distance from the sea, snow sublimation, changes in water inflow, evaporative concentrations, weathering and drainage processes in the catchment, nesting seabirds and aquatic microbiota are among factors which most influence ion composition variability. Comparisons with data from twelve years ago in the same lakes indicate that the warming trend detected at Terra Nova Bay station during this period did not affect the biogeochemistry of water systems. Waters from a lake which recently experienced a lowering of the water level showed a remarkable increase in SO42− concentrations. We hypothesized that the differential mobility of sulphate salts in the Antarctic soils, the biosynthesis of sulphur compounds in the lake, and the progressive decrease of the water volume are factors involved in the increase of SO42− concentrations.

Carlini et al. (1990) reported the presence of Xenarthra (Mammalia) from the Eocene deposits of Seymour Island, Antarctic Peninsula, based on an ungual phalanx from locality RV 8200. The locality, referred to informally as “mammal site” by Woodburne & Zinsmeister (1984), is located at 64°14′21″S, 56°39′44″W at an elevation of 45 m in the middle levels of the shallow marine La Meseta Formation (TELM 5 of Saddler 1988). Carlini et al. (1990) initially identified the phalanx as a megatherioid sloth (Order Tardigrada). Marenssi et al. (1994) revised its identification to ?Tardigrada or ?Vermilingua, by comparison with a primitive myrmecophagid (Order Vermilingua) from the Lower Miocene of Patagonia, whose ungual phalanges are indistinguishable from those of primitive sloths (Carlini et al. 1992). We report a fragmentary tooth of a member of the Tardigrada (Family incertue sedis) confirming the presence of this group in the Eocene of Antarctica.

Eleven aerobic heterotrophic bacteria isolated from soil samples taken at c. 1800 m altitude from La Gorce Mountains, Antarctica, were characterized in terms of carbon source utilization, enzymatic activities and tolerance to environmental stressors. The bacteria typically formed pigmented colonies on agar plates and were initially observed on media designed for isolation of algae and cyanobacteria. The bacteria were purified and assigned to the Actinobacteria, Bacteroidetes or Proteobacteria divisions following 16S rRNA gene sequence analysis. While some of the isolates are most likely to belong to the genera Arthrobacter or Brevundimonas, others may belong to novel genera or species. The Gram-positive Actinobacteria used the widest range of carbon sources for growth. Brevundimonas P7 produced lipases, phosphatases, proteases and glycosyl-hydrolases. The Gram-positive bacteria were more tolerant to freeze-thaw than the Gram-negative isolates. No isolates survived more than 10 minutes ultraviolet irradiation. All isolates were unaffected by 24 h desiccation. This study adds to knowledge of the bacterial diversity of soils from high altitude (1800 m), high latitude (86°30'S) locations within Antarctica.

To reduce the uncertainty in the calculation of Antarctic solid ice fluxes, the firn depth correction (Δh) in Antarctica is inferred from a steady-state firn densification model forced by a regional atmospheric climate model. The modelled density agrees well with observations from firn cores, apart from a site at the origin of fast flowing West Antarctic ice stream (Upstream B), where densification is anomalously rapid. The spatial distribution of Δh over Antarctica shows large variations, especially in the grounding line zone where large climate gradients exist. In places where the grounding line crosses ablation areas, Δh is zero. Along the remainder of the grounding line, Δh values range from typically 13 m in dry coastal areas (e.g. Dronning Maud Land) to 19 m in wet coastal areas (e.g. West Antarctica).

Following a weakening of the semi-annual oscillation (SAO) since the mid-1970s, the half-yearly pressure wave in the Southern Hemisphere has become less significant. As a result, May/June temperatures have decreased in East Antarctica, which has moderated Antarctic warming. Spectral analysis of 87 years of pressure data at Orcadas suggest that the recent weakening of the SAO is part of the natural variability of the Southern Hemisphere circulation on decadal timescales. We interpret the time series of composite Antarctic temperature in terms of the historical strengthening and weakening of the SAO. If the dominant oscillations that occurred in the past prove to be persistent, an accelerated East Antarctic warming trend is expected for the coming decades. There are indications that the strength of the SAO is linked to the Southern Oscillation, in the sense that warm phases of the Southern Oscillation coincide with strong westerlies, a weakly developed SAO and below-average temperatures in East Antarctica. Temperatures on the west coast of the Antarctic Peninsula show strongly deviant patterns, which can not be explained by the same mechanism that applies to East Antarctica.

An ecomorphological study was performed on ten species of the family Artedidraconidae, the most benthic of the suborder Notothenioidei. These species are sympatric on the shelf of the Weddell Sea. The results show that the four genera comprising the family (Artedidraco, Dolloidraco, Histiodraco and Pogonophryne) can be differentiated by just a few morphometric features of their sensory organs and mouth. The genera were also clearly defined by the composition of their diet (benthic and epibenthic), the size of their prey, and their bathymetric distribution. Comparison of the morphological and ecological data shows a very close connection between sensory organs development, the mouth and bathymetric distribution. The morphological and ecological divergence observed can be explained as the result of the rapid adaptive radiation of the artedidraconids. The results confirm that characteristics of the sensory organs and alimentary structures are very suitable for the ecomorphological study of fishes.

The vertical distribution of physicochemical parameters and Chl a at a fixed station in Admiralty Bay (King George Island, South Shetland Islands) was recorded over 73 days during the summer of 1988/89. Temporal variations in Chl a and nutrient stocks in the euphotic zone were associated with changes in the wind/hydrological regime. Northerly winds of late December and early January moved the surface layers towards the outerbay, during which time the chlorophyll stocks remained low in the euphotic zone. Turbulence induced by southerly winds in the second half of January resuspended sediments and benthic diatoms in the shallow (0–20 m) inner inlets of the bay, increasing turbidity and nutrient concentrations at the surface. During the first half of February wind relaxation caused the mass sedimentation of previously resuspended benthic diatoms increasing chlorophyll and phaeopigments in the subsurface layers in deeper sections of the bay. Although turbulence limits phytoplankton biomass accumulation in open waters of the Antarctic, it may have a positive effect (increasing chlorophyll biomass of benthic origin) in coastal pelagic environments during late summer.

Rb-Sr ages of Swanson Formation on Edward VII Peninsula, West Antarctica, indicate a late Ordovician age, 421–432 Ma for regional metamorphism. K-Ar ages of 113–440 Ma, reflect a second thermal metamorphism during emplacement of widespread Cretaceous granites. Rb-Sr ages of five monzogranite/syenogranitic plutons of Byrd Coast Granite are in the range 95–105 Ma (initial 87Sr/86Sr ratios 0.710–0.715) and represent stages of crystallization of anorogenic granite (A subtype). These correlate with Byrd Coast Granite (100–110 Ma) farther east in Marie Byrd Land, and with Cretaceous granitoids on the Campbell Plateau and in southern New Zealand. K-Ar mica/hornblende and fission-track apatite/zircon ages indicate that regional cooling began c. 90–100 M.y. ago immediately after granite emplacement. Uplift continued throughout the peninsula during the period 55–100 Ma (late Cretaceous-early Tertiary), associated with regional uplift in the rift-drift stages of Gondwana break-up at the South-west Pacific spreading centre. Apatite fission track ages show that during late Cretaceous-early Tertiary time the peninsula behaved as two blocks. The Alexandra Mountains were exhumed 20 m.y. before the Rockefeller Mountains and are possibly separated by a fault active initially in the mid-Cretaceous or earlier, and later reactivated in the late Cretaceous-early Tertiary. An averaged uplift rate (50–100 Ma) of 0.025 mm yr−1 is characteristic of the inferred intraplate tectonic setting.

Man's activities have impacted on the Southern Ocean ecosystem for more than 200 years. The exploitation of Southern Ocean resources has followed the same pattern as in other parts of the World Ocean with exploitation starting at the highest trophic levels when seals and whales were taken in the 19th and 20th centuries. After serious over-exploitation of these groups attention moved down the food web to begin exploitation of fish and krill from the late 1960s onwards. The establishment of international management regimes for whales (International Whaling Convention) in 1948 and the remaining marine resources (Convention for the Conservation of Antarctic Marine Living Resources) in 1982 were based on different perceptions of management, the former only considering management by species whilst the latter adopted management at an ecosystem level. These fundamentally different approaches, together with major political interference, have resulted in very different outcomes for management. The Scientific Committee of the IWC developed a sustainable management system, the Revised Management Procedure, in the first half of the 1990s which, however, is still awaiting inclusion into an overall management regime, the Revised Management Scheme, and its acceptance by the Commission. The IWC is now paralysed by political agendas that have nothing to do with scientific management. In contrast, after an early period of slow progress, CCAMLR has improved its performance substantially from the beginning of the 1990s onwards and is now hailed worldwide for its ecosystem approach to sustainable management.

In 2004 as part of the joint Latitudinal Gradient Project in the Ross Sea, cruises of RV Tangaroa and RV Italica along the Victoria Land coast and the Balleny Islands collected 142 species of mollusc (four Polyplacophora, 99 Gastropoda, 37 Bivalvia and two Scaphopoda). About 20% of these species represent new records for the Ross Sea quadrant. The species richness was found to be higher at 71–72°S (Cape Hallett–Cape Adare) and lower at 74–75°S (Terra Nova Bay–Cape Russell) using Shannon-Wiener's H', Pielou's J' and Simpson's λ indices, as well as by using species richness estimators (e.g. ICE, Chao 2, Jack 2). The Balleny Islands (65–67°S), though not exhaustively sampled, show diversity values comparable to those of Terra Nova Bay–Cape Russell. These islands, located in the main Antarctic Coastal Current, appear to represent a crossroads in the Southern Ocean, with mollusc and other invertebrate species present, that have previously been recorded only from the Weddell Sea. The higher diversity in the Cape Hallett–Cape Adare area is not easy to interpret, but could be a result of the intense iceberg scouring off the two capes, observed from seafloor mapping, a factor that is known to enhance species diversity at the regional scale. The existence of a decreasing trend in diversity towards higher latitudes along the Victoria Land coast cannot yet be shown, due to the large gaps in sampling coverage.

Fossiliferous horizons of the Ferrar Group at Carapace Nunatak of southern Victoria Land have yielded the richest and most diverse freshwater Jurassic biota hitherto recorded from Antarctica. Fossil conchostracans are the most important in terms of number of individuals and distributional area. Scanning electron microscopy is used to establish a new genus and species (Carapacestheria balli), and Cyzicus (Lioestheria) disgregaris Tasch is attributed to Carapacestheria disgregaris (Tasch) emend. The conchostracan fauna of the Ferrar Group, characterized by Carapacestheria, is probably of early Middle Jurassic age.