Recently hearing Fred Singer from the USA lecture on what he perceives to be the uncritical ways in which global change has been attributed to anthropogenic effects reminded me of the importance we should attach to those who question our current beliefs. For Fred it was not sufficient that the IPCC had engaged many of the best scientific brains in the world to reach the existing consensus; they might all be wrong because the original question or assumption was wrong. Fred was strongly challenged by the audience of Antarctic scientists, not least because some of his quotations were selective in order to initiate discussion. And we know that there are areas of considerable weakness amongst the several proxies used to compute the rate of temperature change, that we have only poorly quantified and modelled the role of clouds, energy transfer between the oceans and atmosphere, water vapour as a greenhouse gas and that we have yet to be certain that the Global Climate Models really do have all the most significant driving variables. So the IPCC conclusions are drawn on the best available evidence with complementary patterns derived from several different approaches and constitute the best we can do at the moment.

There is a potential threat to marine mammals from acoustic signals emitted by hydroacoustic devices. The impact on the hearing of marine mammals depends on the technical parameters of the instruments and on the exposure of the animal to noise pulses, as well as on the properties of the biological system, that is to say, on the anatomy and the audiogram of the animal. Here, the blue whale, the sperm whale and the beaked whale are taken as examples in an investigation of the potential exposure to noise pulses from the hydroacoustic instruments Hydrosweep and Parasound. Diving depths of the whales and relative speeds of the animals with respect to the survey vessels are taken into account, as well as the area impacted by the equipment, in estimating the level of sound needed to produce “temporary threshold shift” in an animal. The results suggest that auditory damage is only likely if animals pass the transducer at close range and that the impact on marine mammals can be mitigated by implementing prior detection and shut down procedures.

Gentoo penguin Pygoscelis papua is an important component of the Antarctic marine ecosystem. In this paper, we use an indirect approach, a geochemical method combining with 137Cs and 210Pb CRS mode dating, to study the dynamics of the gentoo population and colony on Barton Peninsula, King George Island, in the maritime Antarctic. Five sediment profiles were sampled in the zone between the gentoo penguin colony and tundra vegetation on this peninsula and the sediment sequence and typical elements from penguin guano were analysed. Results showed that the levels for typical elements display a dramatic change at around 5 cm depth, indicating the strong impact of penguin guano. The sediments below 5 cm showed lower concentrations in these elements, suggesting that these sediments had received little impact from penguin guano. By Q-mode factor analysis, a method for decomposing multiple factors, we found that over the past sixty years the gentoo colony showed a rapid enlargement and the tundra vegetation had been destroyed. Possible factors responsible for the enlargement of the penguin colony are tentatively discussed.

Deception Island in the South Shetland Islands is one of the most volcanically active sites south of 60°S. Between 1967 and 1970 three major eruptions devastated large expanses of the landscape and its vegetation. Since 1970 extensive recolonization has occurred on the more stable surfaces. Unheated ground supports several bryophyte and lichen communities typical of much of the Maritime Antarctic, but geothermal habitats possess remarkable associations of bryophytes, many of which are unknown or very rare elsewhere in the Antarctic. Nine geothermal sites and their vegetation are described. Communities associated with more transient sites have disappeared when the geothermal activity ceased. Mosses and liverworts occur to within a few centimetres of the vents where temperatures reach 90–95°C, while temperatures within adjacent moss turf can reach 35–50°C or more and remain consistently between 25 and 45°C. Most of the bryoflora has a Patagonian–Fuegian provenance. It is presumed that, unlike most species, the thermophiles are not pre-adapted to the Antarctic environment, being able to colonize only where the warm and humid conditions prevail. The floristic and ecological importance of these thermophilic communities, and their sensitivity to perturbation by the rapidly increasing annual summer influx of tourists, as well as scientists, has resulted in these unique sites being proposed as components of a new Antarctic Specially Protected Area under the Antarctic Treaty.

Carbon dating of basal peat deposits in Cumberland Bay and Stromness Bay and sediments from a lake in Stromness Bay, South Georgia indicates deglaciation at the very beginning of the Holocene before c. 9500 14C yr BP. This post-dates the deglaciation of one local lake which has been ice-free since at least 15 700 14C yr BP on account of its atypical geomorphological location. The latter indicates the likely presence of floristic refugia on South Georgia during the Last Glacial Maximum from which newly exposed terrestrial and aquatic habitats were rapidly colonized.

A model was used to simulate primary production of benthic microbial mats in Lake Hoare, southern Victoria Land, Antarctica, and to compare potential benthic to planktonic production. Photosynthetic and respiratory characteristics of mats from five depths in the lake were extrapolated across depth, surface area and time, to estimate whole-lake, annual net primary production. Variation in under-ice light regimes resulting from changes in ice thickness and transparency, and light extinction in the water column was examined, and an uncertainty analysis of key model parameters performed. Daily mat production estimates were 0.98–37.83 mg C m−2 d−1, depending on depth and PAR, whereas in situ production of phytoplankton averaged 15% of this. Annual patterns of mat production achieved maximum rates of 15–16 g C m−2 y−1 at 10 m depth when ≥ 5% of ambient PAR was transmitted through the ice covering the lake; observed transmittance values were usually ≤ 5%. Increasing underwater PAR had little effect above 5–7% transmittance, as photosynthesis became saturated at this level. Uncertainties in estimates of maximum photosynthetic rate (Pmax), initial slope of photosynthetic-light response (α) and maximum respiration rate (Rmax) explained 72–99% of uncertainty in model behaviour; Pmax was increasingly important at high light levels whereas α was more important at low light levels, however Rmax exerted the greatest influence under most conditions.

Three hydrocarbon-degrading Rhodococcus strains isolated from polluted Antarctic soils proved to be closely related despite their different origins. Strains had a similar hydrocarbon degradation pattern and optimum growth temperature ranged between 25ºC and 30ºC, showing that strains are psychrotolerant but not psychrophiles. Specific growth rate on rich media ranged between 0.12 and 0.21 h−1, higher than those observed on hydrocarbons as carbon source. Results suggest that in Antarctic contaminated soils, closely related Rhodococcus strains are present and could play an important role in decontamination. Microcosm systems showed that, although the natural microflora respond significantly to the pollutants, bioaugmentation with Rhodococcus strain (ADH), improved biodegradation either alone or mixed with a hydrocarbon-degrading Acinetobacter strain. In comparison with microcosm where only ADH was inoculated, a non-significant decrease in hydrocarbon concentration was observed when ADH was inoculated as mixed culture with a previously tested strain. Pollutants dramatically reduced bacterial groups in soils resulting in a dominance of Pseudomonas. Microcosms showed that when natural microflora has no previous history of exposure to the pollutants, bioaugmentation with autochthonous strains improves degradation of the contaminants. The positive response of the native bacteria to the pollutants leaves the question open as to whether bioaugmentation is necessary when soils have a long previous exposure to hydrocarbons.

We investigated 17 abandoned Adélie penguin (Pygoscelis adeliae) colonies in the Windmill Islands, East Antarctica, in summer 2002/03. Forty radiocarbon dates on penguin bones and eggshells from 13 of these sites indicate a near continuous occupation by breeding penguins in this region for over 9000 years. These dates refine the recent geological record in this region and indicate that deglaciation of the northern islands occurred much earlier than previously suggested. Dietary remains from these sites include at least 23 taxa of cephalopods and teleost fish. Quantification of these remains indicates significant fluctuations in the relative abundance of two of the more common major prey taxa. The Antarctic silverfish (Pleuragramma antarcticum Boulenger) was the most common teleost prey during all time periods represented by the ages of the sites, but preservational factors may explain a gradual decrease in the remains of this species in increasingly older sites. The most common cephalopod in the sediments was the squid, Psychroteuthis glacialis Thiele, which occurred in low numbers in most sites except one (Site 75). An unusually high number of squid beaks preserved in Site 75, dating to approximately 5700–6100 cal. yr BP, does not correlate with a decrease in fish prey at that time. The high number of abandoned penguin colonies (> 200) in the Windmill Islands may be due to population cycles in the past in association with low nest-site fidelity and movement by breeding penguins to new sites within this region.

It is recognized that birds become disorientated at night in the presence of artificial light (Bruderer et al. 1999). Bird strikes on vessels operating in the southern oceans have long been known (Ryan 1991), but few data have been published concerning these events. In the Southern Ocean the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) stipulates that, during fishing operations, deck lighting should be kept to a minimum and be directed inboard and downward (CCAMLR 2003, measures 25-02 and 25-03). However, these measures are designed to keep birds away from fishing gear rather than prevent bird strikes. The problem of bird strikes has been recognized by several territories within the southern oceans and policies to reduce the risk of them occurring are included in several management plans (Ryan & Glass 2001, policy 5.14 and Meere 2002, section 28:1f–1g). These do not, however, address the issue of ice-lights (powerful searchlights used to discern floating ice that might go undetected by radar), which are regarded as essential navigational aids.

Deschampsia antarctica Desv. (Poaceae) is the only native Gramineae found in the Antarctic, where it is restricted to the Antarctic Peninsula and its offshore islands. Its ability to survive the harsh climate has attracted the interest of scientists searching for genes associated with freezing tolerance (Alberdi et al. 2002). For continuing research purposes it would be better if plants did not have to be collected from the field, but could be propagated effectively to provide the necessary experimental material D. antarctica normally reproduces both by seed produced by self-fertilization and also vegetatively from tillers (Holderegger et al. 2003). Vegetative propagation is slow and unable to generate enough plant material for laboratory requirements. This difficulty prompted us to develop a rapid micro-propagation method using tissue-culture methods for the production of large numbers of plants in relatively short periods.

On the basis of observations of Weddell seals (Leptonychotes weddellii Lesson) made in the course of studying shallow-water benthic communities in McMurdo Sound, Antarctica, we suggest that caching and/or defence of uneaten food may be a strategy practiced by this animal. Such a phenomenon is uncommon but taxonomically widespread among vertebrates. Depending on circumstances, it is termed hoarding, caching, or storage and may be short- or long-term, include defence of the resource, or have other variable expressions, with the common threads being deferred consumption and deterrence of consumption by others (Vanderwall 1990). Many vertebrate taxa exhibit hoarding behaviour, including rodents (e.g. Sciuridae), carnivores (e.g. Canidae, Felinidae) and birds (e.g. Corvidae, Picidae). No form of food caching, to our knowledge, has ever been reported in a wild pinniped.

A low diversity plant macrofossil assemblage described from the northern section of Fossilryggen, Vestfjella, Dronning Maud Land, Antarctica, is dominated by matted leaf impressions of Glossopteris sp. cf. G. communis Feistmantel and Glossopteris sp. cf. G. spatulata Pant & Singh, and in situ finely branched Vertebraria indica Royle rootlets. Equisetalean stems, rhizomes and leaf whorls (Phyllotheca australis Brongniart emend. Townrow), isolated seeds, scale-leaves, and fragmentary gymnosperm axes represent minor components of the assemblage. The fossils are preserved in fine-grained, floodbasin sediments and dark palaeosols. Although lacking definitive biostratigraphical indices, the flora is considered to represent a Middle Permian assemblage based principally on lithological and palynological correlation with the southern section at Fossilryggen and broad similarities to mid-Permian plant assemblages elsewhere in Gondwana.

The palynological content of randomly collected sedimentary rock clasts from the till on the south-east slope of the Basen nunatak in northern Vestfjella in western Dronning Maud Land indicate that these sedimentary rocks were derived from strata of Middle Permian age. The palynological content and preservation is similar to palynofloras described from the sedimentary rocks that crop out at the Fossilryggen nunatak to the south-east, therefore, it seems likely that the Fossilryggen area represents the source of the sedimentary rock samples in the Basen till. This is further supported by known ice flow directions obtained from striations and clast fabric measurements in the area.

The Bruce, Discovery, Herdman and Jane banks, all located along the central-eastern part of the South Scotia Ridge, represent isolated topographic highs, surrounded by young oceanic crust (∼5–23 Ma), whose petrological and structural nature is still the subject of speculation due to the lack of relevant data. Surface wave tomography in and around the Scotia Sea region, performed using eight broadband seismic stations and 300 events, shows that the central-eastern part of the South Scotia Ridge is characterized by negative surface wave group velocity anomalies as large as 6% in the period range from 15 s to 50 s. The spatial resolution of our data set (∼300 km) makes it possible to study a specific area (centred at 61°S and 36°W) that includes Discovery Bank and appears to show dispersion characteristics similar to those found beneath the northern tip of the Antarctic Peninsula and southern South America. Surface wave dispersion curves are inverted to obtain 1-D isotropic shear wave velocity profiles that suggest a continental nature of Discovery Bank. Crustal thickness is in the range 23–28 km with a sub-Moho velocity of 4.1–4.2 km s−1. The boundaries of the negative group velocity anomalies are marked by a high level of seismic activity. The depth of the events and their large seismic moment suggest the presence of continental lithosphere. The continental-type crust of this topographic relief is supported by our interpretation of multichannel seismic reflection profiles acquired across this rise, where the observed seismic structures are interpreted as thinned and faulted continental plateau.

The barotropic and baroclinic tides in the Ross Sea were simulated using a primitive equation, sigma-coordinate model, the Regional Ocean Model System (ROMS), for four tidal constituents, M2, S2, K1, and O1. Small elevation amplitudes were predicted over most of the basin, with a combined standard deviation of 30–50 cm. Larger amplitudes, with standard deviations ranging from 50–70 cm, occurred deep within the ice shelf cavity, over the continental slope, and over Iselin Bank. Most of the elevation response was associated with the diurnal constituents (K1 and O1), as was most of the depth-independent (barotropic) velocity response. Baroclinic tides were generated at locations of steep topography for the semidiurnal constituents, but not the diurnal. Diurnal continental shelf waves were generated by the diurnal tides and found to amplify the semidiurnal elevations and baroclinic tidal velocities over the continental slope. Comparisons with observations in both elevation and velocities showed very good agreement for the semidiurnal constituents (M2 and S2) and moderate agreement for the diurnal constituents (K1 and O1). The disagreement for the diurnal constituents was associated with diurnal frequency continental shelf waves, which were overexcited along the shelf break. The baroclinic tides induced both small-scale horizontal and vertical shear in the velocity fields in the Ross Sea.

This paper focuses on the daily cycle of the surface energy balance and the atmospheric surface layer during a detailed meteorological experiment performed near Kohnen base in Dronning Maud Land, East Antarctica, in January and February 2002. Temperature, specific humidity, wind speed and the turbulent scales of these quantities, exhibit a strong daily cycle. The sensible heat flux cycle has a mean amplitude of ∼8 W m−2, while the latent heat flux has an amplitude of less than 2 W m−2, which is small compared to the amplitude of net radiation (∼ 35 W m−2) and sub-surface heat (∼ 25 W m−2). Between ∼ 9 and 16 h GMT convection occurs due to a slightly unstable atmospheric surface layer. At the end of the afternoon, the wind speed decreases abruptly and the mixed layer is no longer supported by the sensible heat input; the stratification becomes stable. At night a large near-surface wind shear is measured due to the presence of a nocturnal jet, which is likely to be katabatically driven, but can also be the result of an inertial oscillation. No strong daily cycle in wind direction is recorded, since both the katabatic forcing at night and the daytime forcing by the large-scale pressure gradient were directed approximately downslope during the period of measurement.

To investigate approaches for parameterizing cloud cover effects in models of surface irradiance, the daily-averaged and hourly irradiances measured at Palmer Station (64°46′S, 64°3′W), McMurdo Station (77°5l′S, 166°40′E) and Ushuaia (54°49′S, 68°19′W) between 1993 and 1997 were compared to irradiance values computed with a clear sky radiative transfer model in which nine empirical cloud-cover correction relationships were included. The cloud cover correction algorithms improved the simulated irradiance by factors of 3 and 3.7 for Palmer Station and Ushuaia, respectively, over the non-corrected irradiances. No single cloud cover correction algorithm worked consistently at the three sites. Therefore, a power function cloud cover correction algorithm was derived from comparisons between the observed spectrally-integrated irradiances and the simulated irradiances at the three locations. New coefficient values for the power function cloud cover correction algorithm for the spectrally-resolved irradiances were also derived at the three sites, and were found to be spectrally-neutral and to differ in magnitude. The general trends in the values obtained for the three sites provide an approach for generalizing cloud cover correction algorithm coefficients to other parts of the Antarctic.

Recent meteorological studies suggest a mixed pattern of climate change in Antarctica: a general cooling of the interior continent and warming in the Antarctic Peninsula over the past several decades (e.g. Comiso 2000, Doran et al. 2002, Vaughan et al. 2003). This note presents 10 years of continuous recording of air and permafrost temperature at Mount Melbourne (74°21′S, 164°42′E) in Northern Victoria Land. Mount Melbourne is a quiescent volcano belonging to a wide-spread volcanic belt which has developed since the Oligocene along the western margin of the Ross Sea, parallel to the Transantarctic Mountains (Fig. 1a). In 1988 a tilt network composed of five continuous recording sensors each equipped with four temperature sensors (Fig. 1b) was installed within the framework of Italian PRNA between the end of 1988 and the beginning of 1989 (Bonaccorso et al. 1995).