Chert and silicified wood from the Permian through Cretaceous of Antarctica contain abundant information on fungal diversity and plant–fungal interactions. The chert deposits represent a particularly interesting setting for the study of plant–fungal interactions because they preserve remains of distinctive high latitude forest ecosystems with polar light regimes that underwent a profound climate change from icehouse to greenhouse conditions. Moreover, some of the cherts and wood show the predominance of extinct groups of seed plants (e.g. Glossopteridales, Corystospermales). Over the past 30 years, documentation of fossil fungi from Antarctica has shifted from a by-product of plant descriptive studies to a focused research effort. This paper critically reviews the published record of fungi and fungal associations and interactions in the late Palaeozoic and Mesozoic cherts and silicified wood from Antarctica; certain fungal palynomorphs and fungal remains associated with adpression fossils and cuticles are also considered. Evidence of mutualistic (mycorrhizal), parasitic and saprotrophic fungi associated with plant roots, stems, leaves and reproductive organs is presented, together with fungi occurring within the peat matrix and animal–fungus interactions. Special attention is paid to the morphology of the fungi, their systematic position and features that can be used to infer fungal nutritional modes.

At Radok Lake, northern Prince Charles Mountains, more than 2500 m of Permian Amery Group strata in the Beaver Lake graben are downfaulted against a Proterozoic metamorphic basement. An irregular blanket of late Cenozoic Pagodroma Tillite, up to 100 m thick, overlies the Permian strata and Proterozoic basement. The metamorphic basement comprises repeatedly deformed, high-grade felsic, mafic, aluminous and minor calc-silicate rocks derived from igneous and sedimentary precursors. Low- to medium-pressure granulite-facies metamorphism, assumed to be the ~1000 Ma event widely recorded in the East Antarctic Shield, was followed by incipient to moderate amphibolite-facies retrogression. Three folding events are recognized. Sporadic occurrences of pseudotachylite in the basement represent seismic faulting after substantial uplift and erosion. At the southern end of Radok Lake the Permian coarse alluvial fan facies, the Radok Conglomerate, is overlain disconformably by the Dart Fields Conglomerate, a basal member of the Bainmedart Coal Measures. Five kilometres along strike the deltaic Panorama Point beds, containing sideritic ironstone strata, are overlain conformably by arkosic sandstones of the basal Bainmedart Coal Measures. The Amery Group is intruded by two alnöite sills and at least five altered alkaline mafic dykes. The Pagodroma Tillite contains reworked marine microfossils and records the erosion of higher latitude Cenozoic marine sequences by an expanding ancestral Lambert Glacier.

Seismic reflection measurements of ice thickness and water-column thickness have been made over the southern and western Ronne Ice Shelf, from which, the seabed elevation has been determined. A 2300 km traverse, covering an area over which little bathymetric data previously existed and at a station interval of 15 km, resulted in 152 new measurements of the seabed elevation. The seismic velocity in the ice shelf was determined using shallow refraction surveys for the snow and firn in the upper 100 m of the ice shelf, and by applying a model assuming a simple temperature profile for the deeper ice. Surface elevations were calculated assuming the ice to be in hydrostatic equilibrium. The estimated error in the seabed elevations is ±15 m. With the addition of the new data there is now complete coverage of the seabed elevation and water-column thickness for Ronne Ice Shelf at a spatial resolution of between 10–100 km. The seabed in the area to the south of Korff and Henry ice rises and the Doake Ice Rumples is about 100 m shallower than had previously been speculated, which will affect the validity of previous assumptions of water circulation and ice-ocean interaction in this area.

Body size, geographical distribution and biomass make Laternula elliptica one of the most important bivalve species of the Antarctic. A complete study on the population dynamics (reproduction cycle, growth, mortality and productivity) of this species from King George Island gave growth parameters for the von-Bertalanffy-growth-function of: L∞ = 112.2 mm, K = 0.160 yr 1, t0 = 0.000 yr. Total mortality was estimated as Z = 0.392 yr−1. Somatic production and mean biomass of two distinct sub-populations were 8.7 and 67.3 g AFDW m−2 yr−1 at Beach & Glacier and 20.0 and 88.6 g AFDW m−2 yr−1 at Punta Elefante. The following P / B values were calculated; Beach & Glacier = 0.129, Punta Elefante = 0.226. It is suggested that these differences are linked to mortality caused by icebergs which is expected to be higher at the shallower Punta Elefante site.

Melt waters cover c. 20% of the McMurdo Ice Shelf during the austral summer. The streams, ponds, and lakes up to 104 m2 in area occur in two types of terrain systems with differing morphological, chemical, and biological characteristics: pinnacled ice (PI) areas with sparse sediment cover, low relief, and little biomass; and ice-cored moraine (ICM) areas with 10–20 cm sediment cover, hummocky topography with up to 20 m relief, occasional mirabilite deposits, and dense benthic cyanobacterial mats. Pond water composition in the two areas is markedly different. PI area melt waters have low salinities, <2270 mg 1−1 total dissolved salts (TDS), and near neutral pH, mean = 7.8. The chemical composition of PI waters closely follows that of diluted sea water, suggesting that the release of ions from the sea ice matrix of the ice shelf is the major solute source. In contrast, ICM area melt waters have a wide range of salinities, up to 60 400 mg 1−1 TDS and alkaline pH, mean = 9.3. The chemical composition in c. 40% of the ICM ponds investigated did not resemble that of sea water, but had higher relative abundances of SO2−4, Na+, K+ and Ca2+. Leaching of local salt deposits, particularly mirabilite, weathering of surficial sediments, and morphological features promoting closed-basin brine evolution are possible contributing factors to the enrichments.

The Cenozoic glacial history of East Antarctica is recorded in part by the stratigraphy of the Prydz Bay—Lambert Graben region. The glacigene strata and associated erosion surfaces record at least 10 intervals of glacial advance (with accompanying erosion and sediment compaction), and more than 17 intervals of glacial retreat (enabling open marine deposition in Prydz Bay and the Lambert Graben). The number of glacial advances and retreats is considerably less than would be expected from Milankovitch frequencies due to the incomplete stratigraphic record. Large advances of the Lambert Glacier caused progradation of the continental shelf edge. At times of extreme glacial retreat, marine conditions reached > 450 km inland from the modern ice shelf edge. This review presents a partial reconstruction of Cenozoic glacial extent within Prydz Bay and the Lambert Graben that can be compared to eustatic sea-level records from the southern Australian continental margin.

Oceanic phytoplankton communities are a mixture of various algal functional groups, all of which are of different sizes, have variable physiologies, and interact differently with disparate herbivores. We suggest that polar plankton communities, and specifically the larger phytoplankton of Southern Ocean HNLC (high nutrient, low chlorophyll) systems, are controlled primarily by bottom-up processes, but that smaller (pico- and nanoplankton) reach an equilibrium that is set simultaneously by light, iron and grazing by microzooplankton. Thus Southern Ocean phytoplankton conforms to the “ecumenical iron hypothesis”, albeit with the further addition of light as an environmental control. Examples of bottom-up controls include iron availability, irradiance regulation (either by the incident surface irradiance as controlled by season and sea ice cover, or by the effects of vertical turbulence and mixed layer depths), and macronutrient availability (silicic acid and nitrate). While the contribution of various phytoplankton taxa varies spatially and temporally within the Antarctic, we suggest that this is largely due to the specific responses of the important functional groups to the patterns of physical forcing and micronutrient inputs, rather than to changes in controls by small and large grazers. Examples of abiotic and biotic controls are examined from representative regions of the Antarctic, including continental shelf regions and open ocean HNLC systems. Results from models further support our contention that bottom-up control of large forms is paramount in the Southern Ocean, but top-down controls play an important part in regulating the equilibrium standing stocks of smaller taxa. If bottom-up control is indeed universal in the Antarctic, then it has profound implications for the understanding of interannual variability, food web structure, and population dynamics of higher trophic levels in both the present and past Southern Ocean.

The concentrations of major, minor and trace metals were measured in water samples collected from five shallow Antarctic lakes (Carezza, Edmonson Point (No 14 and 15a), Inexpressible Island and Tarn Flat) found in Terra Nova Bay (northern Victoria Land, Antarctica) during the Italian Expeditions of 1993-2001. The total concentrations of a large suite of elements (Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Gd, K, La, Li, Mg, Mn, Mo, Na, Nd, Ni, Pb, Pr, Rb, Sc, Si, Sr, Ta, Ti, U, V, Y, W, Zn and Zr) were determined using spectroscopic techniques (ICP-AES, GF-AAS and ICP-MS). The results are similar to those obtained for the freshwater lakes of the Larsemann Hills, East Antarctica, and for the McMurdo Dry Valleys. Principal Component Analysis (PCA) and Cluster Analysis (CA) were performed to identify groups of samples with similar characteristics and to find correlations between the variables. The variability observed within the water samples is closely connected to the sea spray input; hence, it is primarily a consequence of geographical and meteorological factors, such as distance from the ocean and time of year. The trace element levels, in particular those of heavy metals, are very low, suggesting an origin from natural sources rather than from anthropogenic contamination.

We provide our perspective on the species-level taxonomy of notothenioid fishes, the dominant component of the fish fauna of Antarctica. There are 140 species in 45 genera, an increase of 15% since the previous summary in 2000. Biogeographically, 30 species are non-Antarctic, 33 are sub-Antarctic and 77 are Antarctic. The checklist is documented with footnotes that provide the rationale for our decisions. Supplementary Material provides additional details for our decisions on two species of Pogonophryne.

Eighteen paired sites (adjacent to vs away from sea bird nests) and six transects (downslope of nests) across Vestfold Hills were sampled for vegetation, soil nutrients, soil water content and percent rock cover. Three moss and 17 lichen species were recorded, including a new record for the lichen Sarcogyne privigna. Sites adjacent to nesting areas generally had higher soil N and P than sites away from nesting areas; however, larger differences between site locations than within site pairs suggests considerable variation in nutrient input between nesting areas and/or redistribution of nutrients by meltwater around nests. Along transects below nesting sites, average soil total N declined from 0.22% to 0.05% within 2 m from the nest, while average total P declined more gradually from 2343 ppm P to 697 ppm P at 30 m from the nest. Moss and lichen species diversity and mean lichen species abundance were higher in sites adjacent to compared with away from nests. Data from site pairs and transects showed that lichen diversity and abundance increased with increasing soil nutrients, with soil P having a stronger influence than soil N. In contrast, soil nutrients were not significantly associated with moss diversity or abundance. Instead, number of moss species and abundance were positively associated with soil water content.

The nutrient status of microalgae inhabiting sea ice in McMurdo Sound, Antarctica was evaluated during the peak and decline of the spring bloom in November and December. Natural populations of microalgae were analysed for C, N, chlorophyll a, protein, lipid, polysaccharide, and low-molecular-weight carbohydrate content, and for the distribution of 14C-labelled photosynthate into macromolecular fractions. Ratios of N:C and protein to carbohydrate (PR:CHO) were similar to values reported for nutrient-limited phytoplankton. Biochemical ratios and 14C-photosynthate allocation patterns suggest that microalgae from congelation ice habitats may be more nutrient-stressed than those from underlying platelet ice habitats. This trend would be consistent with the presumed gradient of seawater nutrient influx through the platelet layer to the bottom congelation ice habitat. Microalgae from congelation ice subjected to an experimental depletion of nutrients (particularly nitrate) showed decreased N:C, PR:CHO, and allocation of 14C-photosynthate to proteins. This evidence suggests that sea ice microalgae are nutrient-stressed during the peak and decline of the spring bloom in McMurdo Sound, which presumably begins when microalgal biomass concentrations and demands for growth reach or exceed the rate of nutrient supply from underlying seawater.

The Ross Sea is an area of dense water formation within the Southern Ocean, hence it potentially plays an important role for anthropogenic CO2 sequestration. In order to estimate the penetration of anthropogenic carbon in the Ross Sea from total inorganic carbon (TCO2) measurements carried out in 2002–03 Antarctic Italian Expedition, we applied two independent models. Anthropogenic carbon was present throughout the water column. The highest concentrations were associated with the recently ventilated shelf waters, namely High Salinity Shelf Water (HSSW) and Ice Shelf Water (ISW), due to their recent contact with the atmosphere. The lowest concentrations were observed for Circumpolar Deep Water (CDW), due to its relatively older ventilation age. This water mass intrudes onto the shelf in some parts of the Ross Sea and hence is observed in the sampled section, where it is recognizable for its low O2 and high TCO2 concentrations. The overflow of the dense High Salinity Shelf Water out of the continental slope was observed in the area off Cape Adare. Since this recently formed shelf water contributes to the formation of the Antarctic Bottom Water (AABW), this process represents a pathway for anthropogenic carbon export down to the deep ocean.

Meltwater ponds in the Victoria Valley and in the Labyrinth at the head of the Wright Valley of Victoria Land were sampled in January (summer) and October (late winter) of 2004 to establish their geochemistry and stratification, and to compare this with that of coastal meltwater ponds at a similar latitude near Bratina Island. In summer, vertical profiles were measured in 14 ponds; 10 were thermally stratified (maximum ΔT = 11.5°C) and 12 demonstrated a conductivity increase (∼25x) in the lowest 10–20 cm of the water column. When 11 of these ponds were resampled in October, the ice columns were stratified with respect to conductivity and five ponds had highly saline (up to 148 mS cm−1), oxygenated basal brines present under the ice. Basal brines and summer melt waters were Na-Cl dominated, and Victoria Valley pond meltwaters were enriched in Ca relative to the Labyrinth ponds. Early gypsum precipitation directs the chemical evolution of residual brine during freezing. These ponds were enriched in NO3 relative to the coastal ponds at Bratina Island, due to dissolution of nitrate-bearing soil salts, and the reduced influence of marine aerosols and biological productivity on pond chemistry.

A study of feeding selectivity in Notothenia neglecta Nybelin 1951, was carried out between October 1988 and January 1989 at Potter Cove, King George Island, where this is the dominant fish species. The abundance and biomass of benthic organisms from 0–40m were compared with their occurrence in the diet of 142 fish. The Ivlev index indicated that the food items positively selected by the fish were sedentary polychaetes, the isopod Glyptonotus antarcticus, the gammarid amphipod Paradexamine sp., the bivalve Dacrydyum sp., the gastropods Margarella antarctica and Eatoniella sp., and algae. The biomass of the benthic community in the sampling area was low, presumably due to the effects of anchor ice. Despite being pelagic, krill (Euphausia superba) was by far the main food of N. neglecta which is considered a benthic feeder.

Environmental conditions, both external to and within three shallow ponds of the McMurdo Ice Shelf, were measured over an annual cycle between January 1997 and January 1998. We combined this with a study of the response of the benthic microbial mat communities to the transition from summer conditions to winter freezing. Over the study period air temperature was above 0°C for a few days during summer. At this time pond temperatures were higher than air temperatures, with evidence of thermo-haline stratification. The shallow areas of ponds froze between late February and early March, with bottom waters in the deepest pond remaining unfrozen until early June. Minimum winter air temperatures were below −40°C. There was little evidence of freezing point depression due to freeze-concentration of solutes, except at the very bottom of ponds. In the most conductive pond investigated, the temperature of basal freezing was −4°C and conductivity did not exceed approximately 60 mS cm−1 immediately prior to freezing. Microbial mats remained photosynthetically active up to conductivities between 40 and 80 mS cm−1, and were able to acclimate to lowered irradiance associated with ice formation. Although photosynthesis and respiration were reduced by 11% and 40% respectively at temperatures of −2°C compared to 1°C, there was no difference in light harvesting efficiency. Results from this study suggest that light limitation of photosynthesis, or freezing, determine the growth season for the microbial communities, depending on depth.

We investigated the physical conditions of the Spring pack ice environment at Terra Nova Bay to understand their influence on the structure and physiology of sympagic microalgae. Bio-optical methods were used to study the availability and spectral quality of solar radiation, both inside and underneath the ice cover. Pack ice thickness was around 2.5 m, with a temperature between −2 and −7°C. On average, only 1.4% of surface PAR penetrated to the bottom ice and less than 0.6% below platelet ice level. Surface UV-B radiation under the bottom ice was 0.2–0.4%. Biomass concentrations up to 2400 mg Chl a m−3, dominated by two species of diatoms (Entomoneis kjellmannii and Nitschia cf. stellata), showed marked spatial and temporal patterns. Maximum values were in the platelet ice during the first half of November, and in the bottom ice two weeks later. Strong shade adaptation characteristics emerged clearly and explained the relevant abundance of microalgae within the sea ice, with specific absorption coefficients (a*) as low as 0.005 m2 (mg Chl a)−1 and the photo-acclimation index (Ek) in the range of in situ irradiance. The biomass specific production values were low, around 0.12–0.13 mg C mg Chl a−1 h−1. The hypothesis suggesting bottom ice colonization by platelet ice microalgae is supported here.

A saccoderm desmid Mesotaenium berggrenii forma (Mesotaeniaceae) occurring as a major component of the snow algal flora is reported from the Windmill Islands region of Continental Antarctica. Stages of the life cycle of the species are illustrated. The local distribution of the species is outlined, habitat conditions described, taxonomy, reproduction and survival strategies discussed. Morphological and nuclear size classes indicate the possibility of polyploidy in the species.

To provide data on the degree of contamination of the marine ecosystem isomer-specific concentrations of polychlorinated biphenyls, including planar, mono- and di-ortho congeners, were measured in the Weddell seal, the Adélie penguin, the south polar skua, and in two species of Antarctic fish (Trematomus bernacchii and Chionodraco hamatus) from Terra Nova Bay, Antarctica. The results show a clear relation between PCB concentrations and trophic level, in the order fish < Adélie penguin < Weddell seal. The higher values found in the skua appear to be related to its migration to more contaminated lower latitudes. The data for the various PCB congeners were used to calculate toxic potential in the different animals. The 2,3,7,8-TCDD toxic equivalents of coplanar congeners were estimated by the “toxic equivalent factors” (TEFs) approach. The highest values of TEFs were found in the south polar skua and Weddell seal. Values in the other species were considerably lower.

Temperature records in the Antarctic Peninsula have shown a climatic warming of 1.5°C over the past 30 years and a number of ice shelves have retreated. The most dramatic retreat has been that of Wordie Ice Shelf which has undergone a catastrophic disintegration since the 1960s. Understanding the cause and mechanism of the break-up may provide important clues to the fate of ice shelves farther south which, it has been suggested, help to stabilize the West Antarctic Ice Sheet. The break-up of Wordie Ice Shelf has been analysed using Landsat and SPOT imagery. These observations show that the relative contribution of the various input glaciers to the grounding line flux has not altered during the break-up. This means that the effect of the rapid and almost complete removal of the ice shelf has not been transmitted upstream and is not causing a rapid increase in velocities on the input glaciers. The volume of grounded ice in the catchment of Wordie Ice Shelf will thus, be largely unaffected by the break-up and there will be no significant contribution to sea level change. Since other ice shelves around the Antarctic Peninsula are also fed by relatively steep mountain glaciers the effect of the loss of the ice shelves on sea level would be likely to be similarly small.

The Antarctic toothfish (Dissostichus mawsoni Norman) has been considered an occasional large prey item of the Weddell seal (Leptonychotes weddellii Lesson) (Kooyman 1967, Calhaem & Christoffel 1969, Testa et al. 1985, Castellini et al. 1992, Davis et al. 1999, Fuiman et al. 2002). The seal's most common prey is the Antarctic silverfish (Pleuragramma antarcticum Boulenger) as well as benthic and sub-ice fish, cephalopods, and crustaceans (Dearborn 1965, Green & Burton 1987, Plotz 1987, Plotz et al. 1991, Castellini et al. 1992, Burns et al. 1998).