Ross Sea Region Of Antarctica Research Articles

Soil and permafrost in the Ross Sea region of Antarctica: stable or dynamic?

Soils in the Ross Sea Region of Antarctica generally comprise a surface desert pavement and a seasonally thawed active layer over permafrost. Most soils are formed on regolith such as glacial till or colluvium. Mean annual air temperatures range from -18°C to -24°C with low precipitation. The active layer ranges in depth from minimal in higher altitude, colder sites, to near 1 m deep at warmer coastal sites in the northern part of the region. Underlying permafrost may be ice-cemented, or dry with no ice cement. In some areas ice-cored moraine occurs where there is a large body of ice within the subsoil permafrost. Two examples of active gully/fan -forming events, one at Cape Evans and one at Lake Vanda are described. At the Cape Evans event water from a small lake thawed and came into contact with the ice in the underlying patterned ground ice-wedge causing the ice-wedge to melt and extensive gully erosion to occur. A fan-building event near Lake Vanda in the Wright Valley resulted in erosive and depositional features covering a horizontal distance of about 3 km and an altitudinal range of about 1400 m. Such occasional events, can be attributed to warmer than average summers, and were first described in the Ross Sea Region in the 1970s. The Cape Evans and Lake Vanda events are examples of active, rapid, landscape processes and show that landscapes are not as static as is often assumed.

Seamount biodiversity: high variability both within and between seamounts in the Ross Sea region of Antarctica

Seamounts in the Ross Sea were surveyed during the New Zealand IPY-CAML research voyage in 2008. Admiralty seamount, and seamounts of the Scott Island Seamount chain (Scott Island, Scott A, Scott B, Scott South) were sampled to examine variability in benthic faunal communities of seamounts. Multivariate analysis of video and still image data showed that benthic community composition was highly variable both within and between seamounts. The distribution patterns of benthic communities varied considerably, with very high densities of certain taxa in some places, sparse fauna in many others, and highly patchy distributions for others. Dissimilarities between seamounts were influenced by differences in population densities of taxa, the proportions of transects in which taxa were present, and by taxa being restricted to only one seamount or group of seamounts. Scott Island seamount was less similar to the others, despite the greater distances between Admiralty and Scott A and B seamounts. The observed variability in community composition was mainly associated with differences in depth, chlorophyll concentration, and seabed rugosity. Results support an earlier hypothesis that the location of seamounts relative to the Ross Sea gyre could be an important factor determining the composition and abundance of benthic invertebrate communities.

Diversity and distribution of deep-sea shrimps in the Ross Sea region of Antarctica.

Although decapod crustaceans are widespread in the oceans, only Natantia (shrimps) are common in the Antarctic. Because remoteness, depth and ice cover restrict sampling in the South Ocean, species distribution modelling is a useful tool for evaluating distributions. We used physical specimen and towed camera data to describe the diversity and distribution of shrimps in the Ross Sea region of Antarctica. Eight shrimp species were recorded: Chorismus antarcticus; Notocrangon antarcticus; Nematocarcinus lanceopes; Dendrobranchiata; Pasiphaea scotiae; Pasiphaea cf. ledoyeri; Petalidium sp., and a new species of Lebbeus. For the two most common species, N. antarcticus and N. lanceopes, we used maximum entropy modelling, based on records of 60 specimens and over 1130 observations across 23 sites in depths from 269 m to 3433 m, to predict distributions in relation to environmental variables. Two independent sets of environmental data layers at 0.05° and 0.5° resolution respectively, showed how spatial resolution affected the model. Chorismus antarcticus and N. antarcticus were found only on the continental shelf and upper slopes, while N. lanceopes, Lebbeus n. sp., Dendrobranchiata, Petalidium sp., Pasiphaea cf. ledoyeri, and Pasiphaea scotiae were found on the slopes, seamounts and abyssal plain. The environmental variables that contributed most to models for N. antarcticus were depth, chlorophyll-a concentration, temperature, and salinity, and for N. lanceopes were depth, ice concentration, seabed slope/rugosity, and temperature. The relative ranking, but not the composition of these variables changed in models using different spatial resolutions, and the predicted extent of suitable habitat was smaller in models using the finer-scale environmental layers. Our modelling indicated that shrimps were widespread throughout the Ross Sea region and were thus likely to play important functional role in the ecosystem, and that the spatial resolution of data needs to be considered both in the use of species distribution models.

Photobiont selectivity for lichens and evidence for a possible glacial refugium in the Ross Sea Region, Antarctica

Lichens are a symbiosis consisting of heterotrophic, fungal (mycobiont) and photosynthetic algal or cyanobacterial (photobiont) components. We examined photobiont sequences from lichens in the Ross Sea Region of Antarctica using the internal transcribed spacer region of ribosomal DNA and tested the hypothesis that lichens from this extreme environment would demonstrate low selectivity in their choice of photobionts. Sequence data from three targeted lichen species (Buellia frigida, Umbilicaria aprina and Umbilicaria decussata) showed that all three were associated with a common algal haplotype (an unnamed Trebouxia species) which was present in all taxa and at all sites, suggesting lower selectivity. However, there was also association with unique, local photobionts as well as evidence for species-specific selection. For example, the cosmopolitan U. decussata was associated with two photobiont species, Trebouxia jamesii and an unnamed species. The most commonly collected lichen (B. frigida) had its highest photobiont haplotype diversity in the Dry Valley region, which may have served as a refugium during glacial periods. We conclude that even in these extreme environments, photobiont selectivity still has an influence on the successful colonisation of lichens. However, the level of selectivity is variable among species and may be related to the ability of some (e.g. B. frigida) to colonise a wider range of habitats.

Visual recovery of desert pavement surfaces following impacts from vehicle and foot traffic in the Ross Sea region of Antarctica

AbstractSites of past human activity were investigated to assess the visual recovery of the desert pavement following impacts from human trampling and vehicle traffic. Visually disturbed and nearby control sites were assessed using comparative photographic records, a field-based Visual Site Assessment, and Desert Pavement Recovery Assessment. Sites included: vehicle and walking tracks at Marble Point and Taylor Valley; a campsite, experimental treading trial site, and vehicle tracks in Wright Valley; and vehicle and walking tracks at Cape Roberts. The time since last disturbance ranged from three months to over 50 years. This investigation also attempted to determine what has the greatest lasting visual impact on soil surfaces in the Ross Sea region: dispersed trafficking or track formation? Walking tracks remained visible in the landscape (due to larger clasts concentrating along track margins) long after the desert pavement surface had recovered. However, randomly dispersed footprints were undetectable within five years. For many sites, allowing widespread trampling will give lower medium-term visible impact than concentrating traffic flow by track formation. For steep slopes and sites where repeated visits occur, use of a single track is recommended. Some 1950s vehicle tracks remain visible in the Antarctic landscape, but where visually obvious impacts were remediated, evidence of former occupation was almost undetectable.

Synoptic Weather Types for the Ross Sea Region, Antarctica

Abstract Synoptic classifications over the Southern Ocean in the Ross Sea region of Antarctica (50°S–Antarctic coast, 150°E–90°W) have been derived from NCEP reanalysis data (1979–2011), producing a set of six synoptic types for the region. These types describe realistic synoptic conditions for the region and represent the moisture-bearing low pressure systems that circulate around Antarctica. The types are described as follows: low Bellingshausen/Amundsen (L-BA), low (L), zonal (Z), low Ross (L-R), ridge (R), and low Amundsen (L-A). Seasonal frequencies of the synoptic types reflect the seasonal zonal shift of the Amundsen Sea low (ASL) and also correlate well with the Southern Oscillation index (SOI) and the southern annular mode (SAM). Variability in the occurrences of the synoptic types L-R and L-BA indicate a shifting of the position of the ASL farther east (west) toward (away from) the Antarctic Peninsula during La Niña (El Niño) and positive (negative) SAM conditions. A joint linear regression of the SOI and SAM indices show the strongest correlations with the types L-BA and L-R in the spring and quantifies the joint forcing effect of these climate cycles on synoptic variability in the region. As a demonstration of how synoptic classification provides links between large-scale atmospheric circulation and local climate parameters, the synoptic types are related to precipitation and temperature at Roosevelt Island, an ice core site on the Ross Ice Shelf (80°S, 160°W). The synoptic types provide quantification of distinct precipitation and temperature regimes at this site, which allows for more fundamental understanding of the precipitation source regions and transport pathways that drive the variability in snow and ice proxies.

A method for assessing the physical recovery of Antarctic desert pavements following human-induced disturbances: A case study in the Ross Sea region of Antarctica

With increasing visitor numbers an understanding of the impacts of human activities in Antarctic terrestrial environments has become important. The objective of this study was to develop a means for assessing recovery of the ground surface desert pavement following physical disturbance. A set of 11 criteria were identified to assess desert pavement recovery. Assessed criteria were: embeddedness of surface clasts; impressions of removed clasts; degree of clast surface weathering; % overturned clasts; salt on underside of clasts; development of salt coatings; armouring per m2; colour contrast; evidence of subsidence/melt out; accumulation of salt on cut surfaces; and evidence of patterned ground development. Recovery criteria were assigned a severity/extent rating on a scale from zero to four, zero being highly disturbed, and four being undisturbed. A relative % recovery for each criteria was calculated for each site by comparison with a nearby undisturbed control area, and an overall Mean Recovery Index (MRI) was assigned to each pavement surface.To test the method, 54 sites in the Ross Sea region of Antarctica were investigated including areas disturbed by: bulldozer scraping for road-fill, contouring for infrastructure, geotechnical investigations, and experimental treading trial sites. Disturbances had occurred at timescales ranging from one week to 50 years prior to assessment. The extent of desert pavement recovery at the sites investigated in this study was higher than anticipated. Fifty of the 54 sites investigated were in an intermediate, or higher, stage of desert pavement recovery, 30 sites were in an advanced stage of recovery, and four sites were indistinguishable from adjacent control sites (MRI = 100%). It was found that active surfaces, such as the gravel beach deposits at the Greenpeace World Park Base site at Cape Evans, the aeolian sand deposits at Bull Pass, and the alluvial fan deposits of the Loop Moraine field campsite, recovered relatively quickly, whereas less active sites, such as the bulldozed tracks at Marble Point, and Williams Field to McMurdo Station pipeline site on Ross Island, showed only intermediate recovery 20–30 years after disturbance. The slabby grano-diorite surface material at the former Vanda Station site, meant that the impacts that had occurred were hard to detect following decommissioning of the station and site remediation. Desert pavements disturbed by randomly dispersed footprints, temporary field campsites at the Loop Moraine and VXE6 Pond in the Wright Valley, recovered to be undetectable (MRI = 100%) within five years, whereas track formation from repeated trampling, particularly the concentration of larger clasts along the margin of a confined track, persisted for over 15 years (MRI = 82%). The recovery assessment method developed in this study has environmental management applications and potential to advance our ability to predict the recovery of desert pavement following human impacts from activities in Antarctica.

Is climate change affecting rates of dune migration in Antarctica?

Research Article| September 01, 2011 Is climate change affecting rates of dune migration in Antarctica? Charlie S. Bristow; Charlie S. Bristow * 1Department of Earth and Planetary Sciences, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK *E-mail: c.bristow@ucl.ac.uk. Search for other works by this author on: GSW Google Scholar Paul Augustinus; Paul Augustinus 2School of Environment, University of Auckland, Private Bag 92019, Auckland, New Zealand Search for other works by this author on: GSW Google Scholar Ed J. Rhodes; Ed J. Rhodes 3Department of Earth and Space Sciences, University of California–Los Angeles, 595 Charles Young Drive East, Los Angeles, California 90095-1567, USA Search for other works by this author on: GSW Google Scholar Irene C. Wallis; Irene C. Wallis 2School of Environment, University of Auckland, Private Bag 92019, Auckland, New Zealand Search for other works by this author on: GSW Google Scholar Harry M. Jol Harry M. Jol 4Department of Geography and Anthropology, University of Wisconsin–Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin54702-4004, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Charlie S. Bristow * 1Department of Earth and Planetary Sciences, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK Paul Augustinus 2School of Environment, University of Auckland, Private Bag 92019, Auckland, New Zealand Ed J. Rhodes 3Department of Earth and Space Sciences, University of California–Los Angeles, 595 Charles Young Drive East, Los Angeles, California 90095-1567, USA Irene C. Wallis 2School of Environment, University of Auckland, Private Bag 92019, Auckland, New Zealand Harry M. Jol 4Department of Geography and Anthropology, University of Wisconsin–Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin54702-4004, USA *E-mail: c.bristow@ucl.ac.uk. Publisher: Geological Society of America Received: 01 Mar 2011 Revision Received: 05 Apr 2011 Accepted: 07 Apr 2011 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2011 Geological Society of America Geology (2011) 39 (9): 831–834. https://doi.org/10.1130/G32212.1 Article history Received: 01 Mar 2011 Revision Received: 05 Apr 2011 Accepted: 07 Apr 2011 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Charlie S. Bristow, Paul Augustinus, Ed J. Rhodes, Irene C. Wallis, Harry M. Jol; Is climate change affecting rates of dune migration in Antarctica?. Geology 2011;; 39 (9): 831–834. doi: https://doi.org/10.1130/G32212.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Antarctica is the coldest, driest, and windiest continent on Earth, and contains sand dunes, like deserts elsewhere. The structure and age of the cold climate dunes found in the Victoria Valley, Antarctica, are described in the light of changing climate in the Ross Sea region of Antarctica during the late Holocene. Ground penetrating radar (GPR) was used to image sand dune stratigraphy, and optically stimulated luminescence (OSL) was used to determine when the sands were deposited. The timing of sand dune accretion identified from the GPR stratigraphy ranges from the present day to ca. 1.3 kyr B.P. The OSL ages were used to calculate end-point migration rates of 0.05–1.5 m/yr, lower than migration rates from photogrammetry and field surveys undertaken over the past 50 yr. The earliest recorded dune development, ca. 1.3 kyr B.P., was probably controlled by intensification of circumpolar westerlies at that time as well as by drier conditions and lower temperatures that promoted dune stabilization. The dune reactivation ca. 300 yr ago coincides with cooling ca. A.D. 1700–1850, and strengthening of southern circumpolar westerlies. The increase in rate of dune migration after this period and especially the past 200 yr may coincide with the modern rise in CO2 and the warmest temperatures in Antarctica during the past 800 kyr. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

A record of Antarctic surface temperature between 25 and 50 m.y. ago

Research Article| May 01, 2011 A record of Antarctic surface temperature between 25 and 50 m.y. ago Luigi Dallai; Luigi Dallai * 1CNR (Consiglio Nazionale delle Ricerche), Istituto di Geoscienze e Georisorse, Via Moruzzi 1, 56124, Pisa, Italy *E-mail: dallai@igg.cnr.it. Search for other works by this author on: GSW Google Scholar Ray Burgess Ray Burgess 2School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK Search for other works by this author on: GSW Google Scholar Geology (2011) 39 (5): 423–426. https://doi.org/10.1130/G31569.1 Article history received: 14 Jul 2010 rev-recd: 01 Dec 2010 accepted: 05 Dec 2010 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Luigi Dallai, Ray Burgess; A record of Antarctic surface temperature between 25 and 50 m.y. ago. Geology 2011;; 39 (5): 423–426. doi: https://doi.org/10.1130/G31569.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract We present the first Antarctic terrestrial record of climate variations through the Cenozoic, based on the hydrogen isotope composition of hydrothermally altered minerals of intrusive rocks. This new record provides an independent geochemical proxy for continental climatic conditions; whereas, most land surface temperature proxies are biological. The temperature record is consistent with the range predicted by global climate models and proxy records for glacial and pre-glacial conditions in the Ross Sea region of Antarctica. The combined stable isotope (O and H) and age (40Ar-39Ar) determinations of hydrous mineral from Cenozoic igneous plutons and dikes show that the protracted time scale of magmatic activity and extensive hydrothermal exchange with local meteoric waters has preserved a semiquantitative climate signal of intervals in which atmospheric temperatures significantly fluctuated. These data also reveal that glacial episodes comparable with current polar conditions occurred repeatedly prior to geographical and thermal isolation of the Antarctic continent. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Permafrost thermal regime from two 30‐m deep boreholes in southern victoria land, antarctica

ABSTRACTTwo 30‐m deep permafrost temperature‐monitoring boreholes were installed in bedrock, one at Marble Point and one in the Wright Valley, in the Ross Sea region of Antarctica. A soil climate‐monitoring station in till is located near each borehole. The ground surface temperature (GST) was highly correlated with the air temperature at both sites in 2008. Thermal offsets were small (< 1 °C) in the till and negligible in the boreholes. The active layer was thicker in the boreholes than in the till, presumably because of the higher thermal diffusivity of the rock. The measured depth of zero annual temperature amplitude was around 27 m at Wright Valley and 25 m at Marble Point. Permafrost thickness was estimated at about 680 m at Wright Valley and 490 m at Marble Point. The GST history, reconstructed using an inversion procedure, suggests a slight cooling from 1998 to 2003 followed by a slight warming to 2008. Longer temperature records or deeper boreholes would be required to establish if long‐term climate change has occurred. Copyright © 2011 John Wiley & Sons, Ltd.

Crenarchaeota affiliated with group 1.1b are prevalent in coastal mineral soils of the Ross Sea region of Antarctica

The objective of this study was to examine the presence and diversity of Archaea within mineral and ornithogenic soils from 12 locations across the Ross Sea region. Archaea were not abundant but DNA sufficient for producing 16S rRNA gene clone libraries was extracted from 18 of 51 soil samples, from four locations. A total of 1452 clones were analysed by restriction fragment length polymorphism and assigned to 43 operational taxonomic units from which representatives were sequenced. Archaea were primarily restricted to coastal mineral soils which showed a predominance of Crenarchaeota belonging to group 1.1b (> 99% of clones). These clones were assigned to six clusters (A through F), based on shared identity to sequences in the GenBank database. Ordination indicated that soil chemistry and water content determined archaeal community structure. This is the first comprehensive study of the archaeal community in Antarctic soils and as such provides a reference point for further investigation of microbial function in this environment.

The phylogeography of Adelie penguin faecal flora

The gut of animals changes quickly from a totally sterile environment before birth to a numerous and highly diverse microbial community shortly after birth. However, few studies have examined the source of the bacteria colonizing the gut. We used a genetic based approach to investigate the distribution and acquisition of faecal microbial communities by Adelie penguins, Pygoscelis adeliae, breeding in the Ross Sea region of Antarctica by cloning a portion of the 16S rRNA gene and by automated ribosomal intergenic spacer analysis (ARISA). We hypothesized that bacteria were either acquired from the penguins' neighbours or inherited from their ancestors. Samples were collected from Adelie penguin breeding colonies at the north-western edge of the Ross Sea coast through to the southernmost Adelie penguin colonies on Ross Island. Most of the bacterial sequences we obtained were only distantly homologous with previously published sequences. Bacterial taxa appear to have a restricted distribution as the majority of 16S rRNA clones were isolated from only one or two hosts. Faecal bacterial community similarity was strongly negatively correlated with the genetic distance between hosts suggesting that bacterial communities are inherited. There was little support for a correlation between distance between collection sites and community similarity.

Bacterial diversity associated with ornithogenic soil of the Ross Sea region, AntarcticaThis article is one of a selection of papers in the Special Issue on Polar and Alpine Microbiology.

In the Ross Sea region of Antarctica, ornithogenic soils form on land under Adélie Penguin rookeries. Compared with mineral soils of the Ross Sea region, ornithogenic soils are generally high in microbial biomass, organic carbon, and total nitrogen and phosphorus, with high electrical conductivity and large variations in pH. The objective of this study was to assess the bacterial composition of ornithogenic soils from Cape Hallett and Cape Bird in the Ross Sea region using culture-independent methods. Soil clone libraries were constructed and those clones that occurred > or = 3 times were sequenced. The bacterial diversity of the soils was dependent on the presence of penguins. Firmicutes most closely related to the endospore-formers (e.g., Oceanobacillus profundus and Clostridium acidurici) and (or) Gammaproteobacteria belonging to the genus Psychrobacter dominated soils currently occupied with penguins. In contrast, Gammaproteobacteria, closely related to cultured members of the genera Rhodanobacter, Psychrobacter, Dokdonella, and Lysobacter, dominated the soils previously colonized by penguins. Results of this study indicate that despite relatively high nutrient levels and microbial biomass, bacterial communities of ornithogenic soils were not more diverse than those of mineral soils of the Ross Sea region of Antarctica.

Relation between soil classification and bacterial diversity in soils of the Ross Sea region, Antarctica

Soils of the Ross Sea region of Antarctica are among the least diverse ecosystems on earth. Few plants and animals have colonised these soils, but bacteria are distributed throughout. We compared the bacterial communities of soil samples from 5 locations in the Ross Sea region, representing different soil taxonomic groups, using culture-independent methods. Four mineral soils and one ornithogenic soil were analysed. Organic C, Total N, and moisture of the mineral soils were low, total P and EC were variable. In contrast, the water content, organic C, and Total N and P, and EC of the ornithogenic soil were 10–100 fold higher than the mineral soils. Soil pH was alkaline. One thousand and fourteen clones were screened by restriction fragment length polymorphisms. While the majority of the ribotypes were rare, some were dominant and occurred ≥ 3 times in the respective clone libraries. The dominant ribotypes were sequenced and shown to be phylogenetically affiliated with the phyla Acidobacteria, Actinobacteria, Bacteroidetes, Proteobacteria, Deinococcus-Thermus, Firmicutes, Cyanobacteria and Candidate TM7. The closest relatives of the clones retrieved from the mineral soils were uncultured environmental clones or bacterial isolates not assigned to recognised genera. In contrast, the clones from the ornithogenic soil were most closely related to the endospore-formers; Oceanobacillus profundus, Clostridium acidiurici and Sporosarcina aquimarina. We found no convincing evidence that the Haplorthels from Scott Base, Marble Point, and Cape Hallett, have bacterial communities structured fundamentally different from those of Anhyorthels from Bull Pass and Vanda. Nonetheless the composition of the communities did vary substantially and were readily discriminated by multivariate statistics on the basis of soil properties.

A New Species of Nototheniid (Perciformes: Notothenioidei) Fish from Mcmurdo Sound, Antarctica

A new species of nototheniid fish, Cryothenia amphitreta, is described from a single gravid female collected in mid-November 2004 by divers in McMurdo Sound in the Ross Sea region of Antarctica. The new species closely resembles the only known congener, C. peninsulae, collected off the west coast of the Antarctic Peninsula, but differs substantially in pelvic-fin length (13.4 vs. 19.3–24.4% SL), total vertebrae (57 vs. 50–53), body size at maturity (261 vs. 100–144 mm), and interorbital-pit morphology. The neutrally-buoyant C. amphitreta is characterized by a wide, well-defined interorbital pit divided by a raised medial ridge, scales anterior to this depression in the interorbital region, and a dark pigmentation of the mouth, gill, and body cavity linings. This species is protected against freezing by high levels of antifreeze proteins in its body fluids. Phylogenetic reconstruction using the mitochondrial NADH dehydrogenase subunit 2 (mtND2) suggests that C. amphitreta falls within the current designation of the nototheniid subfamily Trematominae.

Groundwater characteristics at Seabee Hook, Cape Hallett, Antarctica

Seabee Hook is a low lying gravel spit adjacent to Cape Hallett, northern Victoria Land, in the Ross Sea region of Antarctica and hosts an Adélie penguin (Pygoscelis adeliae) rookery. Dipwells were inserted to monitor changes in depth to, and volume of, groundwater and tracer tests were conducted to estimate aquifer hydraulic conductivity and groundwater velocity. During summer (November–February), meltwater forms a shallow, unconfined, aquifer perched on impermeable ice cemented soil. Groundwater extent and volume depends on the amount of snowfall as meltwater is primarily sourced from melting snow drifts. Groundwater velocity through the permeable gravel and sand was up to 7.8 m day−1, and hydraulic conductivities of 4.7 × 10−4 m s−1 to 3.7 × 10−5 m s−1 were measured. The presence of the penguin rookery, and the proximity of the sea, affects groundwater chemistry with elevated concentrations of salts (1205 mg L−1 sodium, 332 mg L−1 potassium) and nutrients (193 mg L−1 nitrate, 833 mg L−1 ammonia, 10 mg L−1 total phosphorus) compared with groundwater sourced away from the rookery, and with other terrestrial waters in Antarctica.

Fungal diversity in soils and historic wood from the Ross Sea Region of Antarctica

Microorganisms play a dominant role in Antarctic ecosystems, yet little is known about how fungal diversity differs at sites with considerable human activity as compared to those that are remote and relatively pristine. Ross Island, Antarctica is the site of three historic expedition huts left by early explorers to the South Pole, Robert F. Scott and Ernest Shackleton. The fungal diversity of these wooden structures and surrounding soils was investigated with traditional culturing methods as well as with molecular methodology including denaturing gradient gel electrophoresis (DGGE) using the internal transcribed spacer (ITS) regions of ribosomal DNA for identification. From historic wood and artifact samples and soils adjacent to the huts as well as soil samples obtained from the Lake Fryxell Basin, a remote Dry Valley location, and remote sites at Mt. Fleming and the Allan Hills, 71 fungal taxa were identified. The historic huts and associated artifacts have been colonized and degraded by fungi to various extents. The most frequently isolated fungal genera from the historic woods sampled include Cadophora, Cladosporium and Geomyces. Similar genera were found in soil samples collected near the huts. Sampling of soils from locations in the Transantarctic Mountains and Lake Fryxell Basin at considerable distances from the huts and with different soil conditions revealed Cryptococcus spp., Epicoccum nigrum and Cladosporium cladosporioides as the most common fungi present and Cadophora species less commonly isolated. DGGE revealed 28 taxa not detected by culturing including four taxa which possibly have not been previously described since they have less than 50% ITS sequence identity to any GenBank accessions. Fungi capable of causing degradation in the wood and artifacts associated with the expedition huts appear to be similar to those present in Antarctic soils, both near and at more remote locations. These species of fungi are likely indigenous to Antarctica and were apparently greatly influenced by the introduction of organic matter brought by early explorers. Considerable degradation has occurred in the wood and other materials by these fungi.

Terrestrial microarthropods of Victoria Land and Queen Maud Mountains, Antarctica: Implications of climate change

We review aspects of climate change likely to impact upon the Collembola and mites (microarthropods) of Victoria Land and the Queen Maud Mountains (VLQMM) in the Ross Sea Region of Antarctica. Five important aspects of biological and biological–environmental interactions are identified as key for understanding the impact of climate change on VLQMM microarthropods: (1) Water availability and utilization; (2) mean temperature (which will affect development and population processes) and extreme temperatures (which affect persistence); (3) ultraviolet radiation, although we note that the periods of peak UV irradiance and microarthropod activity do not coincide; (4) dispersal within and between habitats; and (5) potential establishment of invasive species from within and without Antarctica. The current evidence for effects of climate change on VLQMM microarthropods is equivocal, and we advocate targeted experimental and monitoring studies. Finally, we highlight several areas of high priority for future research, particularly on the mite fauna for which detailed information is currently lacking. These are: (1) functional ecology (including thermal biology, feeding and nutrition and water relations); (2) distribution, dispersal and colonization processes and (3) population and community ecology.

DNA sequencing and genetic diversity of the 18S–26S nuclear ribosomal internal transcribed spacers (ITS) in nine Antarctic moss species

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.

Antarctica, Scott Base and its environs

Abstract: The landscape in the vicinity of Scott Base is one of the most singular of landscapes in the already unique environment of the Ross Sea Region of Antarctica. A rich history of human endeavour together with a broad range of physical features such as volcanoes, various glacial landforms, polar beaches and the Dry Valleys with their own glaciers, sand dunes and patterned ground must make it one of the most fascinating areas on earth. This paper highlights some of the more notable of these landscape features.