This study aimed to use nutrients in lake inflows as proxies for assessing human impact and separating this from natural transformations of material in the soil active layer. Nutrients, conductivity and δ18O were monitored in surface and subsurface (using ceramic tipped piezometers) lake inflows during summer in near natural and human impacted catchments. The nutrient levels were highly variable but generally higher during the last weeks of the flow, in both subsurface waters and in human impacted catchments. Up to 2000 μgN l−1 subsurface dissolved inorganic nitrogen (DIN) was measured in human impacted catchments but only 315 μg N l−1 in natural catchments. Subsurface levels of dissolved reactive phosphorus (DRP) were up to 310 μgP l−1 in natural catchments and up to 108 μgP l-1 in human impacted catchments. The maximum levels of both DIN and DRP in surface inflows were much higher in human impacted than in natural catchments. Conductivity and δ18O data showed general enrichment of snowbank meltwater presumably through evaporation from the active layer. This combined with fluctuating nutrient levels in catchment waters indicated that soil brines and decaying organic matter of natural and human origin were possible sources for nutrients and other salts. Marked salinization and substantially increased DIN levels near the research stations indicated that lake waters were receiving nutrients generated by humans.

On Southern Ocean islands the effects of the house mouse on plants are not well understood. In particular, its influence at the landscape scale has largely been overlooked. To address this issue, we systematically mapped the distribution of a keystone, cushion plant species, Azorella selago, and mouse damage to it across Marion Island. Mouse damage was observed in a third of the sampled sites from sea level to 548 m a.s.l. Damage to individual cushions ranged from single burrows to the disintegration of entire cushions. Mouse damage was high in sites with low A. selago density, suggesting that in areas of low cushion density the impact of mice may be substantial. Moreover, it is not simply direct impacts on the A. selago population that are ecologically significant. Azorella selago cushions serve as nurse plants for many epiphyte species, so increasing the altitudinal range of a variety of them, and also house high densities of invertebrates especially in fellfield landscapes. In consequence, this study demonstrates that mice are having a significant, negative impact at the landscape scale on Marion Island, so adding to the growing list of species and ecosystem-level effects attributable to this invasive rodent.

We present evidence for the absence of the George VI Ice Shelf during a brief period in the mid-Holocene and during one or more earlier interstadials or interglacials. Barnacle Bathylasma corolliforme shells sampled from ice shelf moraines at Two Step Cliffs on Alexander Island have been dated to c, 5750–6000 14C yr BP(c. 6550–6850 cal yr BP) and imply seasonally open water in the George VI Sound during this period. Other shells are beyond the range of radiocarbon dating and imply open water during one or more previous interglacial or interstadial period, prior to 40 000 14C yr BP. Our results show that the ongoing collapse of some Antarctic Peninsula ice shelves is not unprecedented.

Meltwater habitats in the Darwin Glacier region, Victoria Land (80°S), were sampled in December 2007 and January 2009 to characterize their microbial and metazoan ecology, nutrient status and geochemistry. Targeted areas included terrestrial ponds of the Grant Valley, Lake Wellman, Tentacle Ridge and Diamond Hill, and supraglacial ponds and cryoconite holes of the lower Darwin Glacier. Geochemistry ranged from Na-Cl dominated terrestrial ponds to Na-HCO3 dominated, dilute supraglacial ponds and cryoconites. All showed the nitrate enrichment typical of inland ponds of Victoria Land (up to 13 g.l-1 NO3-N), with some precipitating nitratine (NaNO3) salt. Elevated pH indicated ongoing photosynthetic processes. Benthic microbial mats were thin and poorly developed, dominated by oscillatoriacean cyanobacteria. Nitrogen-fixing genera were generally absent and diatoms were rare. A large (20 μm long) Cyanothece species was the most abundant cyanobacterium in the water and in sediments of the cryoconites. DNA finger-printing identified distinct differences in cyanobacterial and bacterial community structure between the cryoconites, terrestrial ponds and ponds on glacial margins. Eleven metazoan species were identified, with rotifers being the most abundant. Pond substrate (terrestrial rock, ice-cored moraine or supraglacial ice) proved to be a more significant influence on biogeochemistry than other aspects of geography or climatic conditions.

This review represents the Southern Ocean community’s satellite data needs for the coming decade. Developed through widespread engagement and incorporating perspectives from a range of stakeholders (both research and operational), it is designed as an important community-driven strategy paper that provides the rationale and information required for future planning and investment. The Southern Ocean is vast but globally connected, and the communities that require satellite-derived data in the region are diverse. This review includes many observable variables, including sea ice properties, sea surface temperature, sea surface height, atmospheric parameters, marine biology (both micro and macro) and related activities, terrestrial cryospheric connections, sea surface salinity, and a discussion of coincident and in situ data collection. Recommendations include commitment to data continuity, increases in particular capabilities (sensor types, spatial, temporal), improvements in dissemination of data/products/uncertainties, and innovation in calibration/validation capabilities. Full recommendations are detailed by variable as well as summarized. This review provides a starting point for scientists to understand more about Southern Ocean processes and their global roles, for funders to understand the desires of the community, for commercial operators to safely conduct their activities in the Southern Ocean, and for space agencies to gain greater impact from Southern Ocean-related acquisitions and missions.

In January 1985 a net sampling survey was carried out on the distribution and abundance of euphausiid larvae in the Prydz Bay region. Euphausia superba occurred in low abundance, probably due to sampling preceding the main spawning period. Thysanoessa macrura occurred throughout the study area in consistently high abundance. Euphausia crystallorophias was marginally more abundant within its restricted range. Distinct north-south variations in larval age and developmental stages of T. macrura were observed indicating regional differences in spawning. Euphausia frigida was mainly confined to the upper 200 m of the Antarctic Circumpolar Current. E. superba larvae produced north of the shelf break, between 70°–83°E, moved north-east into the Antarctic Circumpolar Current. Larvae originating on the shelf moved rapidly west in the East Wind drift. E. crystallorophias had the same westward dispersion, but some larvae appeared to return eastward via the Prydz Bay Gyre and remain in the region. The data indicate that most E. superba larvae, providing they survive injuries cold temperature an food deprivation, will leave the area, suggests that Prydz Bay krill may not be a self maintaining stock.

Certain physical factors, substrate type and ice action appear to be important determinants for ascidian distribution. Three different substrate types were sampled at depths between 0–30 m by SCUBA diving: soft bottoms, hard bottoms and moraine deposits. The species found were Aplidium radiatum, Synoicum adareanum, Distaplia cylindrica, Sycozoa gaimardi, Sycozoa sigillinoides, Tylobranchion speciosum, Corella eumyota, Ascidia challengeri, Cnemidocarpa verrucosa, Styela wandeli, Dicarpa insinuosa, Pyura bouvetensis, Pyura discoveryi, Pyura obesa, Pyura setosa, Molgula enodis and Molgula pedunculata. Highest diversity and patchy distribution was found in less stringent environments, where epibiosis is a commmon phenomenon on stolidobranch ascidians. Differences in stalk development were found in the most abundant species Molgula pedunculata and Cnemidocarpa verrucosa. Ice action may be the main factor that determines the absence of ascidians above 15 m in all the stations sampled.

The water and calorific content of fifteen species of mesopelagic sub-Antarctic fish from Macquarie Island were determined. Mean percent water content was 69–82%. Calorific content was highly variable between species, especially in the Myctophidae, where it ranged between 22.6–59.3 kJ·g−1 dry weight. The water and calorific content varied with size class within a species, with the smallest size classes generally having the lowest water content but highest calorific content. These values will be useful for future assessment of energetic transfer between trophic levels and energetic modelling of Southern Ocean ecosystems.

We introduce a new bathymetric compilation of the area around South Georgia in the Southern Ocean. Using a variety of data sources including multi and single-beam swath bathymetry we have constructed a gridded bathymetric dataset of the shelf and near-shelf sea-floor areas. The grid has been constructed using a layered hierarchy dependent upon accuracy of each dataset. The spikes and errors have been checked both manually and with a novel semi-automated process. We discuss the resulting bathymetry and the potential uses of the new dataset.

The origin and nature of seal carcasses scattered around the Ulu Peninsula, James Ross Island, is examined using robust and novel multidisciplinary analysis. Spatial distribution analysis indicates their predominance at low elevations and on surfaces with negligible slope. The seals died throughout the last century. Dental cement increments indicate that the seals died in late winter, and we interpret this to show an influence of the persistence and break-up of sea ice and the appearance of pools/cracks in the northern Prince Gustav Channel on death. Specifically, after being trapped by a late winter freeze-up the seals search for open water, become disoriented by snow-covered flat valleys and move inland. Carcasses from all age groups of crabeater seal are found on land, but inland movement is less notable for Weddell and leopard seals. Although most carcasses appear to have remained unchanged during the last 10 years due to the cold and dry conditions, a few carcasses that are located in sites of snow accumulation and subsequent melting have undergone enhanced decay. Decaying seal carcasses represent loci of nutrient release in a nutrient deficient environment and are colonized by algae, cyanobacteria, lichens and mosses. This research suggests further useful studies for the future.

Detrital zircon populations from two sandstone samples from the lower member (Johnsons Dock Member) of the Miers Bluff Formation at Hurd Peninsula have been dated by the Sensitive High Resolution Ion Microprobe (SHRIMP) U–Pb method. In one of the samples, zircons as young as early Middle Jurassic (Bajocian) age are present. In the second sample, the youngest detrital zircons are Middle Triassic in age. The detrital zircon age spectra indicate that Permian, early Palaeozoic and Meso- to Neoproterozoic zircon bearing rocks were present in the source areas of the Miers Bluff Formation. The sedimentary rocks are intruded by the Hespérides Point Intrusive diorite stock which yielded a U–Pb zircon crystallization age of 137.7 ± 1.4 Ma (Early Cretaceous, Valanginian). These results indicate that sedimentation of the Johnsons Dock Member of the Miers Bluff Formation is bracketed in time between the Bajocian and the Valanginian. The Miers Bluff Formation has been correlated with the Trinity Peninsula Group from the Antarctic Peninsula, based on sedimentological and structural similarity. Since the Trinity Peninsula Group is older than Middle Jurassic a direct chronological correlation is not supported by our new U–Pb zircon data. However, we suggest that the tectonic setting may have migrated in time with deposition of the pre-Middle Jurassic TPG on the peninsula, to Livingston Island where the maximum age for deposition of the MBF is Bajocian (about 170 Ma).

Kohnen Station (75°S, 0°E, 2892 m) is one of the two drilling sites of the European Project for Ice Coring in Antarctica. Snow falls at Kohnen only a few times a year with comparatively high precipitation rates of 1 mm to over 5 mm water equivalent per event. These events contribute considerably to the total annual accumulation of which the long-term mean value is 62 mm water equivalent per year. For ice core interpretation, it is important to understand synoptic processes leading to such high precipitation rates. Our investigation is based on visually observed periods of heavy snowfall at Kohnen during summer campaigns since 2001/2002. The corresponding synoptic situations can be grouped into three categories. Category I is where occluding fronts of eastward-moving low pressure systems reach the plateau, a fairly frequent occurrence. Category II is where lows or secondary lows formed east of the Greenwich Meridian move to the west (retrograde movement), and frontal clouds influence the plateau. In Category III, large-scale lifting processes (due to an upper air low west of Kohnen Station) lead to cloud formation over the plateau of Dronning Maud Land.

This investigation was motivated by the lack of ultraviolet radiation (UVR, 280–400 nm) studies on Antarctic benthic marine microalgae. The objective was to estimate the impact of UV-B (280–315 nm) and UV-A (315–400 nm), on photosynthetic efficiency, species composition, cell density and specific growth rate in a semi-natural soft-bottom diatom community. In both experiments, cell density increased over time. The most frequently observed species were Navicula cancellata, Cylindrotheca closterium, Nitzschia spp., and Petroneis plagiostoma. For both experiments, a shift in species composition and a decreased photosystem II (PSII) maximum efficiency (Fv/Fm) over time was observed, irrespective of treatment. UVR significantly reduced Fv/Fm on days 3 and 10 (Expt 1), disappearing on the last sampling date. A similar trend was found in Expt 2. A significant UV effect on cell density was observed in Expt 1 (day 10) but not in Expt 2. No treatment effects on species composition or specific growth rate were found. Thus, the UV effects were transient (photosynthetic efficiency and cell density) and the growth of the benthic diatoms was generally unaffected. Overall, according to our results, UVR does not seem to be a threat to benthic marine Antarctic diatoms.

Depleted mantle model ages derived from granitoids of the Lassiter Coast Intrusive Suite, sampled over a wide geographical area in eastern Ellsworth Land, Antarctica, cluster between 1000 Ma and 1200 Ma and suggest involvement of Proterozoic crust in the petrogenesis of the suite. Ion-microprobe U–Pb zircon analyses from a small intrusion at Mount Harry, situated at the English Coast, yield a concordant age of 105.2 ± 1.1 Ma, consistent with published ages from other parts of the Lassiter Coast Intrusive Suite. Significant variation in the Sr and Nd isotope composition of the granitoids, along the extrapolation of the Eastern Palmer Land Shear Zone (a proposed terrane boundary) located close to the English Coast, is not evident. However, the isotope signature at the English Coast is more homogeneous than the Lassiter Coast; this variation may relate to geographical proximity to the Pacific margin during intrusion, may reflect subtle changes in basement with a broadly similar character across the proposed terrane boundary, or suggest that any major fault structure is located further to the north, with implications for the kinematics of regional mid-Cretaceous transpression.

A census of pelagic copepods identifies 346 species from 38 families (i.e. 16.7% of all copepods). Among them, 289 species are considered “cosmopolitan” and 57 “endemic”. Most of the species were described in the late 19th or early 20th century. However, due to a resurgence of interest in biological diversity, a large number of exhaustive revisions at various taxonomic levels have recently been initiated. One hundred and thirteen documents covering the census and distribution of copepod species are analysed. The distribution of species in the South Seas is given for 24 sectors chosen in relation to the geographical coordinates of the South Atlantic, South Pacific and Southern Indian oceans and their location with respect to the Antarctic Convergence or the continental shelf. The respective roles of Lagrangian displacement, of the hydrological features characterising the Southern Ocean and of the general ocean currents are emphasised to explain the scattered distributions of the species. Twenty-one species are catalogued as bipolar, 46 species as specifically sub-Antarctic and 222 cosmopolitan ones are probably from sub-tropical/temperate regions.

Thick successions of turbidites are widespread in the Ross–Delamerian and Lachlan orogens and are now dispersed through Australia, Antarctica and New Zealand. U-Pb detrital zircon age patterns for latest Precambrian, Cambrian and Ordovician metagreywackes show a closely related provenance. The latest Neoproterozoic–early Palaeozoic sedimentary rocks have major components, at c. 525, 550, and 595 Ma, i.e. about 40–80 million years older than deposition. Zircons in these components increase from the Neoproterozoic to Ordovician. Late Mesoproterozoic age components, 1030 and 1070 Ma, probably originate from igneous/metamorphic rocks in the Gondwanaland hinterland whose exact locations are unknown. Although small, the youngest zircon age components are coincident with estimated depositional ages suggesting that they reflect contemporaneous and minor, volcanic sources. Overall, the detrital zircon provenance patterns reflect the development of plutonic/metamorphic complexes of the Ross–Delamerian Orogen in the Transantarctic Mountains and southern Australia that, upon exhumation, supplied sediment to regional scale basin(s) at the Gondwana margin. Tasmanian detrital zircon age patterns differ from those seen in intra-Ross Orogen sandstones of northern Victoria Land and from the oldest metasediments in the Transantarctic Mountains. A comparison with rocks from the latter supports an allochthonous western Tasmania model and amalgamation with Australia in late Cambrian time.

Sterechinus neumayeri is an abundant regular sea urchin that lives in the shallow Antarctic waters. This organism has been used as a model system in many fields of the Antarctic biology. Yet, understanding of the evolutionary identity of the species, such as its phylogenetic relationships and divergence time, remains limited. Here, we reconstructed the molecular phylogenies of the species together with two sea urchin species in southernmost South America (Loxechinus albus and Pseudechinus magellanicus), a parechinid species (Paracentrotus lividus) and three strongylocentrotid species (Strongylocentrotus purpuratus, S. intermedius, and Hemicentrotus pulcherrimus) using mitochondrial DNA sequences of 12S rDNA-tRNA(gln) region (877nt) and cytochrome oxidase subunit I (COI, 1079nt). The rate of sequence evolution and the divergence time of the species were then estimated from the trees. The phylogenetic trees reveal that S. neumayeri is a sister group to the lineage of L. albus and P. lividus, and separated from the lineage 24–35 million years ago (m.y.a.). The divergence between S. neumayeri and L. albus coincides with the separation of Antarctica from South America, suggesting that the tectonic event must have provoked the cladogenesis of the species through vicariance.

Studies in a large (30000 km2) sampling grid around Elephant Island, Antarctica, during January–March of four successive years (1990–1993) have shown that one of the water types within the sampling area (Drake Passage water) shows low chlorophyll a in surface waters and a subsurface maximum between 50 and 80 m depth. Ancillary data (beam attenuation, in situ chl a fluorescence) support the view that the extracted chl a values actually do represent increased phytoplankton biomass at depth; other data (oxygen concentrations and upwelling radiance at 683 nm) suggest that the phytoplankton within this subsurface maximum layer are photosynthetically active and do not represent a senescent, sinking population of cells. Such deep chl a maxima were found only in Drake Passage waters; in the other four water types sampled, chl a concentrations were maximal in surface waters and decreased with depth. Phytoplankton biomass and activity in Drake Passage waters is suggestive of a nutrient limitation for phytolankton growth in surface waters. Nutrient concentrations of N, P, and Si were high throughout the euphotic zone at all stations, and hence it is unlikely that any macronutrient would be limiting. The data presented in this paper support the hypothesis of Martin and colleagues that availability of Fe may limit phytoplankton biomass in pelagic Antarctic waters, but not in coastal waters where Fe concentrations are relatively high. All other reports on the effects of Fe on Antarctic phytoplankton have utilized deck incubations from which it is difficult to extrapolate such evidence of nutrient limitation to in situ conditions. Our data represent the first in situ evidence linking Fe limitation to the paradox of high macronutrient concentrations and low phytoplankton biomass in Antarctic pelagic waters.

Calcium carbonate precipitation in sea ice is thought to potentially drive significant CO2 uptake by the ocean. However, little is known about the quantitative spatial and temporal distribution of CaCO3 within sea ice, although it is hypothesized that high quantities of dissolved organic matter and/or phosphate (common in sea ice) may inhibit its formation. In this quantitative study of hydrous calcium carbonate as ikaite, sea ice cores and brine samples were collected from pack and land fast sea ice between September and December 2007 during two expeditions, one in the East Antarctic sector and the other off Terre Adélie. Samples were analysed for CaCO3, salinity, dissolved organic carbon/nitrogen, inorganic phosphate, and total alkalinity. No relationship between these parameters and CaCO3 precipitation was evident. Ikaite was found mostly in the uppermost layers of sea ice with maximum concentrations of up to 126 mg ikaite per litre melted sea ice being measured, although both the temporal and horizontal spatial distributions of ikaite were highly heterogeneous. The precipitate was also found in the snow on top of the sea ice at some of the sampling locations.

Samples of phyto- and zooplankton were collected in the Indian sector of the Southern Ocean (38–67°S, 18–84°E) and analysed for organochlorine residues (PCBs and pesticides). The PCB concentration in particulate matter (mainly phytoplankton) appeared to be high and similar to that of temperate zones: 0.7 μg g−1 dry weight. Contamination levels were more constant expressed per water volume than per dry weight, and seven times lower (1.2 μg m−3) than in northern temperate zones (8.8 μm−3 in the North Sea). The Antarctic ecosystems are thus less contaminated than temperate ones — as expected — but the very low phytoplankton biomass present cause high PCB levels per unit of biomass. These results confirm the necessity of using different systems of units in order to correctly express the contamination levels and to identify the main mechanisms responsible for the accumulation of stable pollutants. PCB levels in netplankton samples (mainly zooplankton) were comparable with phytoplankton on a dry weight basis (0.7 μm−3), lower on a lipid weight basis (5.8 μg g−1 lw for netplankton, 16.3 for particulate matter) and were much higher per seawater volume (27.2 μg m−3 for netplankton, 1.2 for particulate matter). Netplankton contamination is comparable in the Antarctic (0.35 μg g−1 dw) and the North Sea (0.70) since zooplankton feeding on phytoplankton has similar levels of contamination in both ecosystems. Lindane, heptachlor epoxide, dieldrin, DDE and DDT were observed in various samples at trace levels. The high DDE/DDT ratio reflects the more recent origin of Antarctic organochlorines.