Conservation of the high seas marine environment poses a significant challenge to policy-makers and managers. Marine conservation efforts are often hindered by the lack of data and the difficulties in addressing multiple, and typically conflicting uses. The majority of extant Marine Protected Areas (MPAs) are in coastal or tropical regions within national jurisdiction. Conservation of high seas MPAs has emerged on the international agenda as a critical issue requiring the application of novel approaches, international cooperation and political will. Knowledge and understanding of the marine environment and data on marine biodiversity are all typically limited for the high seas, and the use of surrogates to assist in the identification of areas of high conservation value is one possible mechanism to address and potentially overcome these limitations. Drawing upon a database spanning more than 20 years and containing approximately 140 000 records of seabird sightings at sea, this study assesses the potential use of seabirds as surrogates for marine biodiversity in the Indian sector of the Southern Ocean. At-sea ranges, species diversity and the distributions of endangered species may be appropriate selectors or filters to identify areas with high conservation values. Integrating policy with science provides an appropriate mechanism to identify and prioritise MPAs in the Southern Ocean.

The capacity of the polar flora to adapt is of increasing concern given current and predicted environmental change in these regions. Previous genetic studies of Antarctic mosses have been of limited value due to a lack of variation in the markers or non-specificity of the methods used. We examined the power of five microsatellite loci developed for the cosmopolitan moss Ceratodon purpureus to detect genetically distinct clones and infer the distribution of clones within and among populations from the Windmill Islands, East Antarctica. Our microsatellite data suggest that the extraordinarily high levels of variation reported in RAPD studies were artificially elevated by the presence of contaminants. We found surprisingly little contribution of asexual reproduction to the genetic structure of the Windmill Islands populations, but more loci are required to determine the distribution of individual clones within and among populations. It is apparent that Antarctic populations of C. purpureus possess less genetic diversity than temperate populations, and thus have less capacity for adaptive change in response to environmental variation, but more markers are needed to resolve the total genetic diversity in Antarctic C. purpureus and other mosses.

We have sequenced the 18S–26S nuclear ribosomal DNA ITS region from the genome of nine different moss species from the Ross Sea region of Antarctica. This relatively quick and simple technique enables these species to be readily distinguished, facilitating their taxonomic identification. Only a single moss shoot is required, and for identification of these bryophytes it is only necessary to determine a few hundred nucleotides of the DNA sequence in a single sequencing reaction. Several previously unidentified Antarctic moss specimens were readily characterized by comparison with ITS sequences of known moss species. The relationships between species and locations previously detected by the RAPD (Random Amplified Polymorphic DNA) technique were confirmed by DNA sequencing, demonstrating that the two techniques can be complementary for molecular analysis of the ecology of mosses in Antarctica.

The liquid soil water contents in the seasonally thawed layer (active layer) were characterized from seven soil climate monitoring sites - four coastal sites from south to north (Minna Bluff, Scott Base, Marble Point and Granite Harbour), and inland sites from low to high altitude (Wright Valley, Victoria Valley and Mount Fleming). Mean water contents ranged from 0.013 m3 m-3 near the surface at Victoria Valley to 0.33 m3 m-3 near the ice-cemented layer at Granite Harbour. The coastal sites have greater soil water contents than the McMurdo Dry Valley and Mount Fleming sites, and moisture contents increase with depth in the active layer. The Wright Valley site receives very little infiltration from snowmelt, with none in most years. All other sites, except Mount Fleming, received between one and four wetting events per summer, and infiltrated water moved to greater depths (≈ 10–25 cm). The Scott Base and Granite Harbour sites are on sloping ground and receive a subsurface flow of water along the ice-cemented permafrost. Our findings indicate that water contents are low with very little recharge, are greatly influenced by the local microclimate and topography, and show no significant increasing or decreasing trend over 10 years of monitoring.

Soil chronosequences in till deposits emplaced during glacial retreat in the Central Transantarctic Mountains are described. Discrepancies between the degree of soil development and reported cosmogenic surface exposure ages suggest slower, weaker soil development in this region than encountered in other areas of Antarctica. The study sites (Dominion Range, Mount Achernar and Ong Valley) were located between 83° and 85°S, at altitudes of 1600–2200 m, on the edge of the polar plateau. Soil landscape maps show a gradation of soil properties across landscape units that were designated as homogenous/single-event drifts in previous smaller-scale studies. Along transects away from the current ice edge, the depth to underlying ice thickened (from 2 cm to > 80 cm), soil became more weathered, saltier and less alkaline, and horizonation became more pronounced. Soil thickness, clast abundance and soil chemistry are all consistent with a two-layer mode of soil formation. We suggest that a thin, clast-rich surface horizon, originating from weathering of supraglacial debris, overlies a thick, clast-poor sublimation till. The supraglacial debris has a finite contribution to soil volume, whereas sublimation offers an ongoing source of soil material that thickens the soil from its base.

Recent studies of Falkland Islands seabird diets have found that Gonatus antarticus is a major prey item for a number of penguin species. Rockhopper (Eudyptes chrysocome), gentoo (Pygoscelis papua) and Magellanic (Spheniscus magellanicus) penguins breeding in the Falklands are estimated to consume several thousand million Gonatus per annum, with mean dorsal mantle lengths of 28–42 mm. Aspects of the distribution and growth of the G. antarcticus stock in the vicinity of the Falkland Islands are discussed.

Knowledge of spatial distribution is fundamental to ecological studies and crucial for conservation and management of species and biodiversity, but detailed, large-scale spatial data are lacking for most taxa. Although the Adélie penguin is one of the most intensively studied Antarctic vertebrates, spatial data that could aid in ecological study and conservation management are incomplete. We undertook a large-scale survey of the current breeding distribution of Adélie penguins along 3800 km of the East Antarctic coastline. The survey increased the number of known breeding locations by 50% and revealed that the breeding distribution has expanded in some parts of the survey region over the past two to three decades. The expanding breeding distribution may reflect underlying population dynamics of sustained growth and resultant density dependent effect on dispersal and movement from established breeding sites to new sites. The comprehensive, large-scale distribution data from this study will form a baseline for assessing any future changes in Adélie penguin breeding distribution, provide data for developing spatial models for predicting future changes in breeding distribution under plausible scenarios of environmental change, and contribute to the development of metapopulation models by providing estimates of local colonization and extinction probabilities under specific conditions of metapopulation change.

Bacterial community composition during summer was analysed in surface and bottom waters of the oligotrophic shallow (4.5 m) Lake Limnopolar (Livingston Island, South Shetland Islands, Antarctica), using 16S rRNA gene clone libraries and sequencing. Up to 61% of the 16S rDNA sequences found were closely related to sequences retrieved from lakes, glaciers or polar systems. The distribution of these sequences was not homogeneous, with vertical differences found in both bacterial taxa composition and isolation source of the closest match from GenBank. In the surface sample 86% of the sequences were related to bacteria found in soils, seawater or gut microbiota, probably explained by waterborne transport from the catchment, by wind through sea sprays, or local bird activity. Conversely, in the deep samples, 95% of the sequences were closer to bacteria typically described for lakes, glaciers or polar systems. The presence of benthic mosses covering the bottom of the lake favours a more stable deep layer leading to the existence of this biological heterogeneity through the water column, although the lake does not show physical-chemical stratification in summer. This study illustrates a strong influence of external factors on the microbial ecology of this model Antarctic lake.

Available information about seabird breeding population trends on Stinker Point (Elephant Island, Maritime Antarctic Peninsula) is outdated by decades. This study reports current numbers of breeding species, and evaluates population trends over 28 years. We counted breeding pairs of seabirds along all ice-free areas on Stinker Point during two distinct periods (summers of 1985/86–1991/92 and 2009/10–2013/14). Thirteen species currently breed in the area: four Sphenisciformes, four Procellariiformes, one Suliforme and four Charadriiformes. Chinstrap penguin Pygoscelis antarcticus has the highest number of breeding pairs (4971±590), followed by gentoo penguin Pygoscelis papua (1242±339). Comparisons between the two intervals showed declining trends for almost all breeding populations, although southern giant petrels Macronectes giganteus are experiencing a subtle population growth. Population decreases in locations with low human disturbance, such as Stinker Point, may indicate sensibility to climate and environmental change and need further investigation.

Two surveys were carried out in the Ross Sea region during February and March 2004 and 2008 from the New Zealand RV Tangaroa. Fishes were sampled on the continental shelf and slope of the Ross Sea, and on adjacent seamounts to the north, mainly using a large demersal fish trawl and a large mesopelagic fish trawl. Parts of the shelf and slope were stratified by depth and at least three random demersal trawls were completed in each stratum, enabling biomass estimates of demersal fish to be calculated. Fish distribution data from these two surveys were supplemented by collections made by observers from the toothfish fishery. A diverse collection of over 2500 fish specimens was obtained from the two surveys representing 110 species in 21 families. When combined with previous documented material this gave a total species list of 175, of which 135 were from the Ross Sea shelf and slope (to the 2000 m isobath). Demersal species-richness, diversity and evenness indices all decreased going from the shelf to the slope and the seamounts. In contrast, indices for pelagic species were similar for the slope and seamounts/abyss but were much lower for the shelf.

Eight hundred photosynthesis-irradiance relationships were determined in the shelf waters adjacent to Palmer Station, Antarctica during the spring/summer periods of 1991–94. Biomass specific maximum photosynthetic rate, PBmax, and the light limited photosynthetic efficiency, αB, were poorly correlated to the physical forcing and nutrient regimes at the sampling stations. The two photosynthetic parameters, however, did strongly covary indicating the minimum irradiance required to saturate photosynthesis, Ik, was relatively constant in this highly variable environment. The variability in Ik could partially be attributed to both depth in the water column and time of the year, with the highest values occurring for surface samples during the summer period of peak incident irradiance. Given this and the significant dependence of Pmax on phytoplankton biomass, a simple empirical model for primary productivity was developed. An independent test of the model was performed on data collected in a mesoscale offshore grid and predicted primary production was found to be within 13% of measured values. Although there are limitations to this approach (i.e. exclusion of diel periodicity in photosynthetic response), these results provide relatively robust estimates of daily primary production for the Southern Ocean.

Radiocarbon dating was carried out on the total organic carbon of 19 lacustrine and marine sediment samples from the Bunger Hills. The results indicate that radiocarbon contamination is negligible throughout two sediment sequences from a fresh water lake. In contrast, two sequences from marine basins are irregularly influenced by the Antarctic Marine Reservoir Effect, which today amounts to more than 1000 years, depending on the degree of dilution with meltwater. All dated sediments were deposited during Holocene time.

An assessment is made of the ability of the Coupled Model Intercomparison Project 5 (CMIP5) models to represent the seasonal cycles of biogeochemistry of the Ross Sea over the late twentieth century. In particular, sea surface temperature, sea ice concentration, surface chlorophyll a, nitrate, phosphate and silicate, and the depth of the seasonal thermocline (measuring vertical mixing) are examined to quantify the physical-biogeochemical capabilities of each model, and to provide for ‘ranked’ model ensembles. This permits critical assessment of modelled Ross Sea biogeochemical cycling, including less well observed variables such as iron and vertically integrated primary production. The assessment enables determination of model output confidence limits; these confidence limits are used to examine future model scenario projections for consideration of potential ecosystem changes. The future scenarios examined are the representative concentration pathways rcp4.5 and rcp8.5. Our study suggests that by the end of the twenty-first century under rcp4.5 and/or rcp8.5 that there will be average increases in sea surface temperature, surface chlorophyll a, integrated primary production and iron, average decreases in surface nitrate, phosphate and silicate, and relatively large decreases in the depth of the seasonal thermocline and percentage coverage by sea ice in the Ross Sea.

The 16S rRNAs of nine new species of prokaryotes, that had been isolated from four lakes of the Vestfold Hills, have been sequenced. These sequences were compared with those of their closest taxonomic relatives available from publicly available databases. The Antarctic species were of wide diversity with representatives from the domains Archaea and Bacteria (sensu Woese). Generally, they were most closely related to organisms from marine environments. The sequence dissimilarity between the rRNA sequences of the Antarctic strains and their nearest known relatives suggest they diverged from each other much earlier than the establishment of their modern Antarctic habitat. The conserved nature of the 16S rRNA molecule suggests it may not be as useful for detecting evolutionary change in Antarctic prokaryotes as distinct from non-Antarctic prokaryotes. Although the optimal temperature for growth of each species is well above the temperature of its environment, each has a reduced optimal temperature for growth when compared with its taxonomic counterpart from non-Antarctic environments. The vast majority of Antarctic prokaryotes remains to be described.

There are seven emperor penguin (Aptenodytes forsteri) colonies distributed throughout the traditional boundaries of the Ross Sea from Cape Roget to Cape Colbeck. This coastline is c. 10% of the entire coast of Antarctica. From 2000 to 2012, there has been a nearly continuous record of population size of most, and sometimes all, of these colonies. Data were obtained by analysing aerial photographs. We found large annual variations in populations of individual colonies, and conclude that a trend from a single emperor penguin colony may not be a good environmental sentinel. There are at least four possibilities for census count fluctuations: i) this species is not bound to a nesting site like other penguins, and birds move within the colony and possibly to other colonies, ii) harsh environmental conditions cause a die-off of chicks in the colony or of adults elsewhere, iii) the adults skip a year of breeding if pre-breeding foraging is inadequate and iv) if sea ice conditions are unsatisfactory at autumn arrival of the adults, they skip breeding or go elsewhere. Such variability indicates that birds at all Ross Sea colonies should be counted annually if there is to be any possibility of understanding the causes of population changes.

During the early Pliocene a dynamic marine-based ice sheet retreated from the Wilkes Land margin with periodic ice advances beyond Last Glacial Maximum position. A change in sand provenance is indicative of a more stable Mertz Glacier system during the Late Pleistocene. East Antarctic Ice Sheet (EAIS) dynamics were evaluated through the analysis of marine diamictons from Integrated Ocean Drilling Program (IODP) site U1358 on the Adélie Land continental shelf. The warmer than present conditions of the early Pliocene coupled with the site's proximity to the landward sloping Wilkes Subglacial Basin provided the rationale for the investigations at this site. Based on visual core descriptions, particle size distributions, and major and trace element ratios, we interpret the origin of lower Pliocene strata by intermittent glaciomarine sedimentation with open-marine conditions and extensive glacial advances to the outer shelf. Heavy mineral analyses show that sand-sized detritus in the lower Pliocene strata was sourced from local intermediate to high-grade metamorphic rocks near Mertz Glacier. In contrast, Pleistocene diamictons exhibit a larger contribution from a prehnite-pumpellyite greenschist facies suggesting supply via iceberg rafting from northern Victoria Land. From this sedimentological evidence, we postulate a shift from a dynamic EAIS margin in the early Pliocene to possible stabilization in the Pleistocene.

In certain regions of the Southern Ocean, tidal energy is believed to foster the mixing of different water masses, which eventually contribute to the formation of deep and bottom waters. The Ross Sea is one of the major ventilation sites of the global ocean abyss and a region of sparse tidal observations. We investigated M2 tidal dynamics in the Ross Sea using a three-dimensional sigma coordinate model, the Regional Ocean Model System (ROMS). Realistic topography and hydrography from existing observational data were used with a single tidal constituent, the semi-diurnal M2. The model fields faithfully reproduced the major features of the tidal circulation and had reasonable agreement with ten existing tidal elevation observations and forty-two existing tidal current measurements. The differences were attributed primarily to topographic errors. Internal tides were generated at the continental shelf/slope break and other areas of steep topography. Strong vertical shears in the horizontal velocities occurred under and at the edges of the Ross Ice Shelf and along the continental shelf/slope break. Estimates of lead formation based on divergence of baroclinic velocities were significantly higher than those based on barotrophic velocities, reaching over 10% at the continental shelf/slope break.

Classification of 162 sample plots of lichen vegetation from the Argentine Islands region, Antarctica, yielded two main groups, the Usnea complex and the Mastodia-Rinodina complex, comprising four and six subordinate communities, respectively. Communities of the Usnea complex typically occur in inland sites with steep slopes, characterized by low chloride, ammonia and phosphate concentrations. Communities of the Mastodia-Rinodina complex occur close to the shore and in areas occupied by birds, where concentrations of chloride, ammonia and phosphate were relatively high. Within each vegetation complex species composition is related to factors indicating nutrient status (chloride and ammonia concentration, distance from the sea), as well as to variables indicating different microclimatic conditions (elevation, aspect, exposure, moisture, and gradient). In canonical correspondence analyses of the data a large part of species variation could not be explained by the environmental variables studied (elevation, gradient, slope aspect, distance from the sea, direction of the sea, presence of guano, exposure, moisture, chloride, ammonia, phosphate and nitrate concentrations). It is suggested that temporal variability in mineral concentrations and the lack of information on differences in length of the growing season at the sample sites are, to a large extent, responsible for this.

The analysis of two high resolution hydrological datasets acquired during the 1997 and 2001 summers across the Antarctic continental shelf-break near Cape Adare (Ross Sea) is presented. The main focus of these cruises was the investigation of the overflow of the High Salinity Shelf Water (HSSW). This dense and salty water mass forms along Victoria Land and flows northward, descending the slope near Cape Adare. Water types characterizing the study area are detected through vertical salinity profiles and by the horizontal distributions of the temperature and salinity. Temperature and salinity hydrological sections obtained by means of objective analysis method well describe the water masses interactions at the shelf/slope edge. The 1997 dataset shows evidence of a strong HSSW signature on the slope, but it is difficult to quantify the spatial scales involved in the spreading mechanism, because the overflow takes place at the edge of the investigation area. The 2001 data, collected at the same position with improved spatial and temporal resolution, clearly indicates the absence of a “true” HSSW downslope process. Even though no estimation of the amount of downslope flow can be given at present due to the resolution of the available dataset, it is possible to get a better phenomenological picture of the process by comparing the two years.