In March 1993 the Atmospheric Environment Service's monitoring network across Canada registered ground-level fluxes of solar ultraviolet-B radiation (UVBR) that were the highest on record. This effect was correlated with the spring-time depletion of ozone in the northern upper atmosphere, and AES predicted that the average depletion over Canada could be this severe or worse for the next 15–20 years. These reports heightened awareness amongst the Canadian public as well as the scientific community about the Antarctic ozone hole, and about the most recent UVBR and atmospheric research findings from Antarctica. The causes and biological impacts of high latitude ozone depletion is but one example where information derived from one polar zone is of vital interest to those living in, or otherwise concerned with the other. In this and other research areas the time is appropriate for a bipolar perspective on Antarctica.

The diet of the Antarctic blue-eyed shag Phalacrocorax atriceps bransfieldensis was analysed based on the identification of the prey items in 50 regurgitated casts collected at Duthoit Point, Nelson Island, in February 1991. Fish remains occurred in 100% of the casts and represented 68% by number and 90% by weight of the total prey items. From a total of 2112 otoliths found, 1176 fish specimens were identified belonging to four demersalbenthic species: Harpagifer antarcticus, Notothenia neglecta, Nototheniops nudifrons and Trematomus newnesi. Equations to estimate total length and weight from otolith length are provided. H. antarcticus and N. neglecta were the most frequent (92%) and important by weight (66%) respectively. Cephalopod beaks found indicate benthic octopods as the second group in importance after fish. Other invertebrates such as polychaetes, gastropods, bivalves and crustaceans were only occasional. The presence of algae and stones in the casts is attributed to accidental ingestion. Our results are in general agreement with those published for other Antarctic localities which indicate that P. atriceps is a benthic coastal feeder, with fish as its main food.

Maritime Antarctic freshwater lakes and their catchments are inherently simple systems in an environment which is characterized by strong seasonality. Such lakes offer excellent opportunities to study the interaction of water chemistry and plant communities. The response of diatom species to environmental gradients was assessed by constructing a diatom and water chemistry dataset from 59 lakes at two locations (Livingston Island, South Shetland Islands and Signy Island, South Orkney Islands). Results indicate that diatom species abundance is predominately related to nutrient and salinity gradients. The dataset will be used to create transfer functions which can be applied to sediment core diatom assemblages to reconstruct historical patterns of lake chemistry.

The geographical distribution and depth zonation of Eusirus perdentatus Chevreux, 1912 in the eastern Weddell Sea and adjacent Lazarev Sea (Antarctica) is described. A total of 963 individuals of this carnivorous predator caught during six successive cruises at 71 stations between 176 and 799 metres water depths were used. Individuals of E. perdentatus have been kept alive for nearly five months in the laboratory. During this period females released 53 juveniles in April. Oocytes and embryos of females have been counted and measured. The duration of embryonic development in E. perdentatus was estimated at c. 12 months, using an empirical relationship based on the mean diameter of 4390 fertilized eggs. There is strong evidence that this species is semelparous with hatching of juveniles at the end of austral summer. Two methods, herein termed as Year Class Model and Moult Class Model, have been applied in order to describe the growth of females by means of cumulative length-frequency data.

Five volatile organic compounds were identified throughout 1991 in the hypolimnion of Organic Lake. These were dimethylsulphide (DMS), dimethyldisulphide (DM2S), dimethyltrisulphide (DM3S), dimethyltetrasulphide (DM4S) and phenol. The concentration of these compounds increased with lake depth. The concentration of DMS and DM2S was higher in the sediment than in the water column. Carbon disulphide occurred only in the sediment. DMS was the only volatile organic compound detected in the epilimnion of the lake, where its concentration increased from winter onwards. The source of DMS was not dimethylsulphoniopropionate (DMSP). This was determined by hydroxylation of the sample with NaOH. There was no change in the concentration of DMS but the concentration of DM2S increased dramatically while the concentrations of DM3S and DM4S decreased concomitantly. This has important implications in the estimation of DMS derived from DMSP by hydroxylation when organic polysulphides are also present. The stability of the hypolimnion of Organic Lake was reflected by the lack of change in temperature, density, redox potential and the relatively constant concentration of volatile organic compounds throughout the year. Potential sources of the volatile organic compounds are discussed in relation to the isolated nature of the lake.

Data collected on four large-scale surveys around the subantarctic island of South Georgia provide information on the variability in the distribution of chlorophyll and inorganic nutrients during the austral summer and winter. During three summer surveys, surface water cholorophyll and nutrient concentrations were highly patchy over scales ranging from a few to hundreds of kilometres. The highest measurement of chlorophyll a was 8 mg m−3 and a wide range of nutrient concentrations were found; 5–32 mmol m−3 NO3−N, 1.1–2.2 mmol m−3 PO4−P and 8–60 mmol m−3 Si(OH)4−Si. In winter, chlorophyll and nutrient levels were far more uniform, with chlorophyll concentrations lower and nutrient concentrations generally higher than in summer. The spatial variability in nutrient concentrations was due to a variety of factors acting over a range of scales, however biological processes appeared most important in creating the mesoscale patchiness around the island. Although phytoplankton abundance and nutrient concentrations were not directly correlated, the scales of variability were clearly similar.

Adamussium colbecki is one of the dominant members of the nearshore benthic community around Antarctica (Nicol 1966, Dell 1974). It has been studied from a systematic and biogeographic point of view since the beginning of this century (Smith 1902, Pelseneer 1903). However, detailed knowledge of its biology and ecology has been only acquired during the last decade (Stockton 1984, Berkman 1990, Berkman et al. 1991, Mauri et al. 1990, Nigro et al. 1992, Nakajima et al. 1982).

The Lagrelius Point Formation (?Barremian–Aptian) is the basal unit of the Gustav Group and crops out on the north-west coast of James Ross Island. It consists of about 250 m of coarse-grained siliciclastic rocks. The type section of the Lagrelius Point Formation is defined here from just south of Lagrelius Point. The measured section comprises the uppermost 80 m of the unit and mainly consists of clast-supported, boulder, cobble to pebble conglomerates; very coarse to medium-grained sandstones occur rarely. Four sedimentary facies are recognized. A disorganized conglomerate facies (1) is interpreted as having been deposited from non-cohesive debris flows and high density gravelly turbidity currents. Inversely graded conglomerate facies (2) and normally graded to graded stratified conglomerate and pebbly sandstone facies (3) reflect sedimentation from high density gravelly turbidity currents. Massive and parallel stratified sandstone facies (4) is thought to record deposition from high density sandy turbidity currents. Two types of facies assemblages have been recognized. A major channel assemblage, represented by the lower part of the measured section and the minor channel assemblage forming the upper part of the section. The total succession is thought to represent the aggradation of a major submarine braided channel followed by the establishment and subsequent infill of a series of minor channels in a marginal terrace.

A varied suite of sapphirine-bearing and quartz-undersaturated granulites, the Taynaya Paragneiss, occur as boudins and enclaves within the c. 2500 Ma old felsic orthogneisses of northern Vestfold Hills. Highly magnesian varieties with XMg (=100x(Mg/(Mg+Fe)) near 95 preserve the assemblage sapphirine + enstatite + spinel, whereas sapphirine + cordierite + sillimanite + corundum occurs in aluminous and feldspathic types with XMg near 90. Phase equilibria and relative thermometry based on Al2O3 solubility in enstatite indicate equilibration of these assemblages at c. 830–880°C and 0.35–0.85 GPa. There is no evidence for the extreme temperatures (1000–1100°C) previously proposed for early metamorphism in the Vestfold Hills, and no indication in the metamorphic assemblages of isobaric cooling prior to 2500 Ma. Two types of metasomatism have altered the bulk rock compositions near boudin and enclave margins. Cordierite rinds locally formed on corundum-sillimanite granulites reflect interaction with magmatic precursors to the enclosing felsic gneisses, as supported by the isotopic and chemical compositions of cordierite channel volatiles. More extensive metasomatism producing schistose phlogopite + sapphirine rinds on all boudins involved infiltration of a LILE-enriched fluid which introduced K2O, H2O, Fe, Rb, Ba and minor Sr along the boudin margins. Whole rock geochemistry of Taynaya Paragneiss unaffected by this metasomatism is consistent with their derivation from evaporitic mudstones, and implies the existence of a basement older than the dominant 2500 Ma orthogneisses.

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 East Antarctic Craton contains only one substantial outcrop of Palaeozoic–Mesozoic strata between 0° and 150°E; this lies in Mac. Robertson Land, on the eastern margin of the northern Prince Charles Mountains. These rocks are known as the Amery Group (Mond 1972, McKelvey & Stephenson 1990) and comprise dominantly fluviatile sandstones, with subordinate shales, coals and conglomerates. The lower formations of the Amery Group, the Radok Conglomerate and Bainmedart Coal Measures, contain a diverse Stage 5 palynomorph assemblage indicating a Baigendzhinian–Tatarian age (late Early–Late Permian, hereafter abbreviated as mid–Late Permian; Dibner 1978).