The public expects all Arctic scientists to know about polar bears, and all Antarctic scientists to be expert on the “ozone hole”. Exposure to bears or the effects of ozone depletion can result in death and are both thus newsworthy. Yet whilst deaths from bears continue to be news, some parts of the media appear to be showing “ozone fatigue” — the public are deemed to have heard enough of this story. Too bad — because the story can only get worse before it gets better.

Depth distribution data were compared for 172 European and 157 Antarctic benthic invertebrate species occurring in the respective shelf areas. Antarctic species showed significantly wider depth ranges in selected families of the groups Bivalvia, Gastropoda, Amphipoda and Decapoda. No differences were found in Polychaeta, Asteroidea and Ophiuroidea, where European species also showed comparatively wide bathymetric ranges. These extended levels of eurybathy in the Antarctic benthos may be interpreted either as an evolutionary adaptation or pre-adaptation to the oscillation of shelf ice extension during the Antarctic glacial-interglacial cycle.

Particulate organic matter was collected in the coastal waters of Terra Nova Bay during the Oceanographic Campaign of the Italian Antarctic Research Programme in summer (January–February) 1990. Particulate matter composition was analysed for organic carbon and nitrogen, carbohydrates, proteins, lipids, nucleic acids (DNA and RNA) and ATP. A vertical stratification was evident in the study area, and resulted from prior melting of the pack ice. Suspended organic matter in the mixed layer and below the mixed layer differed in quantitative and qualitative composition. Except for ATP, all the biochemical components showed higher concentrations in the mixed layer than in the deeper waters. The particulate organic matter in Terra Nova Bay was mostly detrital and of algal origin.

The distribution of dimethylsulphide (DMS), together with the precursor dimethylsulphonio-propionate (DMSP) and the oxidation product dimethylsulphoxide (DMSO), was measured in melt waters on the McMurdo Ice Shelf in the immediate vicinity of Bratina Island. Conductivity in these sulphate dominated ponds was extremely variable, ranging from 0.106–52.3 mS cm−1. Similarly, chlorophyll a concentrations in the pond waters (1–150 μg 1−1) and mats (1.4–33 μg cm−2) differed considerably. The biomass was dominated by benthic felts of phototrophic cyanobacteria, which might act as a source of biogenic sulphur compounds in the ponds. The mean (and ranges) of concentrations of dissolved sulphur compounds (nmol 1−1) were: CS2 0.16 (<0.04–1.29); DMSPd 0.6 (<0.07–8.4); DMS 3.5 (<0.07–183); DMSO 27.9 (15.5–184.5). Very high concentrations of DMSO were ubiquitous in the ponds in the ice-cored moraine region of the ice shelf, with dissolved concentrations having been 1–2 orders of magnitude greater than those of DMS or DMSPd. It is difficult to ascribe the formation of DMSO solely to the conventionally accepted pathways of DMS oxidation by either bacterial activity or photochemical reactions. A direct biosynthetic production from phytoplankton or bacteria might be involved which means that DMSO in aquatic environments could act as a significant source of DMS rather than as a sink as generally supposed.

The total annual food consumption of the seabird and seal community breeding at lles Kerguelen was estimated to be 1.8×106 t in 1985. This biomass included c. 0.99×106 t (55%) of crustaceans, 0.46×106 t (26%) of myctophid fish, 0.07×106 t (4%) of other fish species, and 0.26×106 t (15%) of squid. During the same year, the mass of prey consumed in Crozet waters was previouly estimated to be 3.1×106 t, the total food consumption in the Indian Ocean area including the two archipelagos thus totalling c. 5×106 t in 1985. Four species of top predators, the king penguin, macaroni penguin, elephant seal, and fur seal, consumed 59% and 56% of the amount of prey eaten in 1985 by the whole community at Kerguelen and Crozet islands, respectively. Between 1962 and 1985, population changes of these four species induced 18 and 41% increases in their food consumption at Kerguelen and Crozet islands. Population changes included a moderate increase in the number of macaroni penguins and a marked rise of king penguin populations. Assuming that the diet of king penguin was similar in 1962 and 1985, its population increase will have required a concomitant increase of 0.6×106 t in the consumption of myctophid fish in Crozet and Kerguelen waters.

In 1991 Chamsocephalus gunnari <1 year old were sampled at Shag Rocks on 18 January and off five bays on the north-east coast of South Georgia between 19 January and 12 February. Two separate size-groups of 31–46 mm and 55–87mm standard length (SL) were found at Shag Rocks. However, samples taken off Possession Bay, South Georgia, within two days of those at Shag Rocks, contained only one size-group of 25–57 mm SL. Samples taken at other locations at South Georgia also contained only single size-groups between 24–63 mm SL. The mean and median length of the large size-group at Shag Rocks are significantly larger (P<0.001) than those at South Georgia. For those at South Georgia there was an apparent growth of around 0.76% SL d−1, which is comparable with previous reports of their growth rate during the first year. Based on this growth rate, the differences between the average size of the larger size-group of C. gunnari at Shag Rocks and those at South Georgia indicates that they hatched at periods separated by about three months. This and other published evidence suggests there may be separate populations of C. gunnari at Shag Rocks and South Georgia.

The food and energy requirements of adult emperor penguins parenting chicks were examined at Auster (about 11 000 pairs) and Taylor Glacier (about 2900 pairs) colonies during the winter, spring and summer of 1988. Tritiated water-derived estimates of food consumption trebled during the five-month period of chick care, ranging from 2.3 kg d−1 in winter when chicks were <5% of adult mass, to 6.3 kg d−1 in summer, when chicks represented 40–50% of adult mass. These food consumption rates were equivalent to the acquisition of 11.4 MJ d−1 and 33.4 MJ d−1 metabolizable energy in winter and summer respectively. Chick provisioning was not accompanied by a major increase in food consumption by adults. Adults assimilated 84–92% of their daily food intake themselves and retained the remainder for the chick. The food ration of chick for the three seasons (42 kg) constituted only about 9.5% of adult maintenance requirements during the same period. Adults consumed an estimated 482 kg of food (including the ration for the chick), which amounted to about 10 700 t and 2800 t of fish and squid consumed by the breeding populations at Auster and Taylor Glacier, respectively.

During January 1994 seven meltwater ponds on the McMurdo Ice Shelf were investigated for their content of biogenic iodinated and brominated volatile hydrocarbons. An efficient purge and trap system in combination with a powerful gas chromatographic separation and an electron capture detector achieved detection limits of 0.02–0.4 ng 1−1, depending on the different substances. The following compounds could be identified and quantified: CH3I, CH2I2, CH2C1I, CHBr3, CH2Br2, BrCH2CH2Br, CHBr2Cl, and CHBrCl2. This is the first time that 1,2–dibromoethane has been detected as a biogenic substance in the environment. In contrast to many other aquatic systems, where CH3I is found to be the most volatile iodine compound, CH2I2 showed the highest concentration in all ponds falling in the range of 5–20 ng 1−1. In three of seven ponds investigated, CH2CII was the second abundant iodinated substance. CHBr3 usually exhibited concentrations in the range of 2.5–8.6 ng 1−1. BrCH2CH2Br, previously not observed as a biogenic compound, was found to have concentrations similar to those of bromoform and even exceeded the bromoform content in two ponds and the CH2Br2 content in all ponds. Whether cyanobacteria, the dominant organisms in the ponds, are responsible for this distribution pattern must be clarified by further investigations.

Lake Wilson, a perennially ice-capped, deep (>100 m) lake at 80°S in southern Victoria Land was investigated in January 1993. Water chemistry and physical structure showed three distinct layers; an upper c. 35 m mixed layer of low salinity, moderately turbid water; a less turbid mid layer, 20 m thick of slightly higher salinity and supersaturated with oxygen; and a deep 20 m brackish layer (conductivity c. 4000 μS cm−1) with anoxic conditions in the lower 5 m. Extreme supersaturation of N2O (up to 400 times air saturation) together with high nitrate concentration (4000 mg m−3) was recorded in the deep layer. Phytoplankton biomass and photosynthetic activity was confined to the upper mixed layer and the band of supersaturated dissolved oxygen located at 40–55 m appears to represent a relict layer from when the lake level was lower. The evidence from a comparison of profiles between 1975 and 1993 suggests that Lake Wilson has risen 25 m since 1975, synchronous with a period of lake level rise in the McMurdo Dry Valleys lakes to the north at 77°S. Geochemical diffusion models indicate that Lake Wilson had evaporated to a smaller brine lake about 1000 yrs BP, which also fits the pattern shown by the McMurdo Dry Valleys lakes. Climate changes influencing lake levels have thus covered a wide area of southern Victoria Land.

The Tertiary stocks (Meander Intrusives) cropping out along the coasts of the Ross Sea were sampled for a palaeomagnetic study during the sixth Italian expedition to northern Victoria Land. Laboratory investigations concerned magnetic mineralogy and remanent magnetization. Minerals of the magnetiteulvöspinel series occur in the rocks from all stocks, with low-Ti titanomagnetite usually prevalent. Haematite and goethite occur in small amounts as alteration products. Large secondary components commonly screen the characteristic remanent magnetization and were removed by thermal or AF demagnetization at temperatures or peak-fields higher than 360°C and 20 mT respectively. A total of 10 VGPs were obtained from radiometrically dated rocks (42–22 Ma); the averaged position (69°S, 334°E; α95=9.9°) is the first middle Tertiary palaeomagnetic pole for East Antarctica, and gives evidence for a reversal in the course of the APW path. This evidence is not substantially altered by a supposed tilt-correction consistent with geophysical and geological models for the uplift of the Transantarctic Mountains. No definite conclusion about relative movements between East Antarctica and the Antarctic Peninsula can be drawn from the existing palaeomagnetic data.

A regional chemical boundary termed the ‘salt line’, in the Vestfold Hills of East Antarctica, has been investigated using X-ray diffraction and electron probe analyses of surficial salts, and conductivity of surficial sediments. West of the salt line, halite and thenardite are abundant. These salts are derived from dispersal of marine aerosols, saturation of sediment by seawater during postglacial marine transgression, and glacial dispersal of salt-saturated fjord bottom sediments. East of the salt line, subglacial calcium carbonates and salts formed by chemical weathering of their substrates occur. Chemically and morphologically diverse minerals form the weathering products. They include two minerals not found previously in Antarctica, dypingite and hydromagnesite, and the first confirmed occurrence of brushite.

Fisher Massif consists of Mesoproterozoic (c. 1300 Ma) lower amphibolite-facies metavolcanic rocks and associated metasediments, intruded by a variety of subvolcanic and plutonic bodies (gabbro to granite). It differs in both composition and metamorphic grade from the rest of the northern Prince Charles Mountains, which were metamorphosed to granulite facies about 1000 m.y. ago. The metavolcanic rocks consist mainly of basalt, but basaltic andesite, andesite, and more felsic rocks (dacite, rhyodacite, and rhyolite) are also common. Most of the basaltic rocks have compositions similar to low-K island arc tholeiites, but some are relatively Nb-rich and more akin to P-MORB. Intermediate to felsic medium to high-K volcanic rocks, which appear to postdate the basaltic succession, have calc-alkaline affinities and probably include a significant crustal component. On the present data, an active continental margin with associated island arc was the most likely tectonic setting for generation of the Fisher Massif volcanic rocks.

The seasonal and spatial variation of downward longwave radiation (L↓) at the surface of the Antarctic ice sheet is studied using data from four stations. L↓ is found to depend on the fourth power of the surface temperature but on the sixth power of the temperature at the top of the surface inversion layer. The former result is shown to be a consequence of the dominance of longwave radiation in the surface energy balance while the latter raises some questions concerning the radiative properties of Antarctic clouds. Simple parametrizations of L↓ as a function of temperature are suggested; these may find application in validating General Circulation Model radiation calculations over Antarctica.