bluuebunny/crossref_metadata_2025 huggingface dataset:
The distribution and abundance of viruses in the Southern Ocean during spring
Authors: Marchant Harvey , Davidson Andrew , Wright Simon , Glazebrook John
Published: December 2007

The concentrations of viruses, bacteria, chroococcoid cyanobacteria and chlorophyll a were determined in surface waters of the Southern Ocean during spring. Viral concentrations declined southward from around 4 × 106 ml−1 near Tasmania to a minimum of around 1 × 106 ml−1 at the Polar Front. South of the Front, virus concentrations increased again, reaching around 4 × 106 ml−1 in the sea-ice zone south of 60°S. Bacterial concentration decreased southwards across the Southern Ocean from around 6.5 × 105 ml−1 near Tasmania to < 1.0 × 105 ml−1 in the sea-ice zone. Cyanobacteria accounted for < 8% of the prokaryotes. There was no significant relationship between viral abundance and eithercyanobacterial or chl a concentration. Viral and bacterial concentrations were not significantly correlated north (P {0.10 < r < 0.20}) or south (P {0.20 < r < 0.5}) of the Polar Front. The virus to bacteria ratio (VBR) was between 3 and 15 in the open ocean but varied between 15 and 40 in the sea-ice region. These virus concentrations and VBRs indicate that viruses are no less important in Southern Ocean ecosystems than elsewhere in the world's oceans.
Ice-active substances associated with Antarctic freshwater and terrestrial photosynthetic organisms
Authors: Raymond James A. , Fritsen Christian H.
Published: December 2007

Macromolecular substances that cause pitting and other modifications of growing ice crystals were found to be associated with cyanobacterial mats, eukaryotic algae and mosses from Ross Island and the McMurdo Dry Valleys, Antarctica. Ice-pitting activities were largely retained by dialysis membranes with molecular weight cut-offs of up to 300 kDa. Unlike most aqueous solutes, the ice-active molecules were not excluded from the ice phase during freezing. The ice-pitting activities of each of the samples tested was destroyed by exposure to temperatures between 45 and 65°C, suggesting that they have a protein component. Ice-active substances were not found in cyanobacteria or mosses from temperate climates, but ice-activity was found to be associated with mosses from cold habitats in North America. Although the function of the ice-active substances is not known, their apparent confinement to cold environments suggests that they have a cryoprotective role.
Pilot shallow drilling on the continental shelf, Dronning Maud Land, Antarctica
Authors: Kristoffersen Yngve , Strand Kari , Vorren Tore , Harwood Dave , Webb Peter
Published: December 2007

A light, mining drill rig deployed from the stern of a research vessel has been used to carry out shallow drilling in 212 m water depth on the continental shelf in the eastern Weddell Sea. Penetration was 15 m below the seabed with 18% recovery in the 31 hours available for the experiment. The recovered glacigenic sediments are predominantly volcanic material of basaltic and andesitic composition with petrological characteristics and age similar to the continental flood basalts exposed in Vestfjella, about 130 km upstream from the drill site. The sediments include a reworked marine Miocene diatom flora. The material documents oscillations of the East Antarctic Ice Sheet over the past 30 ka. The lowermost diamicton probably represents a deformation till, and the grounding line retreated past the drill site 30 km from the shelf edge about 30 kyr BP. A readvance occurred during the Late Wisconsin Glacial Maximum. Assuming a reservoir correction of 1300 yr, marine conditions existed at the site between 10.1-7 kyr BP, and later at least between 2.8 and 2.5 kyr BP. The stratigraphy at the site has been disturbed by iceberg ploughing and/or contact between the ice shelf and the sea floor during local advances after 2.5 kyr BP.
Science in Antarctica – a matter of quality
Authors: Drewry D.J.
Published: December 2007

Antarctic research has progressed steadily from the era of reconnaissance studies into a period of problem-oriented scientific investigation. The International Geophysical Year and the intensive work of the 1960s and 1970s have established fundamental knowledge of Antarctic environmental systems on which present and future activities can be planned. Antarctic scientists of all nationalities are now eager to accept and exploit the challenges presented by global change programmes. At its XXth meeting in Hobart in September 1988, SCAR proposed an Antarctic component for inclusion in the ICSU International Geosphere–Biosphere Programme. Antarctic science thus considers itself sufficiently mature to be able to contribute effectively to programmes of world scope. Indeed, involvement in such activities may be seen as mandatory in order to continue to underscore the credibility and mainstream relevance of Antarctic scientific endeavours.
Habitat use and diet as biogeographic indicators for subantarctic Ectemnorhinini (Coleoptera: Curculionidae)
Authors: Chown S.L.
Published: December 2007

Most of the species in the Ectemnorhinin are cryptogam feeders, angiosperm feeders representing a minority. It is hypothesized that this dearth of angiosperm feeders is due to previous climatic conditions, which precluded angiosperm herbivory, but allowed for the exploitation of a diverse cryptogamic flora, and that only with the post-glacial warm-up of the Subantarctic has angiosperm herbivory become possible. When examined in the light of the Quaternary history of the South Indian Ocean Province islands, evidence obtained from a study of the habitat use, diet and morphology of species within the tribe supports this hypothesis.
Permian Glossopteris and Elatocladus megafossil floras from the English Coast, eastern Ellsworth Land, Antarctica
Authors: Gee Carole T.
Published: December 2007

Plant megafossils collected from the previously unexplored English Coast of eastern Ellsworth Land have yielded the first Glossopteris leaves from the Antarctic Peninsula tectonic province. Collecting at Erehwon Nunatak recovered numerous spatulate leaves of consistent morphology, most likely pertaining to one natural species, and described here as Glossopteris erehwonensis sp. nov., as well as fragments of Phyllotheca and Equisetum. The large sample size, the predominance of Glossopteris leaves, the low species diversity, and the lack of characteristic Early Permian (Gangamopteris) and Early Triassic (Dicroidium, Lepidopteris, Pleuromeia) taxa suggest a Permian, probably Late Permian, age for the Erehwon Nunatak beds. These rocks are thus significantly older than any other sedimentary rocks known from Palmer Land and Ellsworth Land. A second flora, collected from Henkle Peak, consists exclusively of the remains of Elatocladus planus, a conifer which probably dominated forests in this area during the Jurassic. The plant megafossils support correlation of the sedimentary rocks with those of the Middle–Late Jurassic Latady Formation of south-eastern Antarctic Peninsula and eastern Ellsworth Land.
The distribution of Prasiola calophylla (Carmich.) Menegh. (Chlorophyta) in Antarctic freshwater and terrestrial habitats
Authors: Broady Paul A.
Published: December 2007

Specimens of Prasiola collected from habitats not experiencing nutrient enrichment from birds are considered to be P. calophylla. The alga has three distinct growth forms; uniseriate filaments, narrow ribbons and expanded sheets. Reproduction is by aplanospores and fragmentation of the thallus. The known Antarctic distribution is disjunct with only two records outside Victoria Land. However, it is widespread in the latter region. The alga is absent from areas where there are high salt concentrations in waters and soils. Elsewhere it is common in streams and on water-flushed ground as well as occurring on terminal ice-faces of glaciers and as chasmoendolithic growths. Ribbons are found mostly on the lower surfaces of stones, and uniseriate filaments on the exposed surfaces of the stream beds of seasonal melt streams. Expanded sheets occur in less vigorous water flows. There is a need for further culture and field studies in order to understand the factors which control morphological development and distribution patterns.
Microbial biomass, photosynthesis and chlorophyll a related pigments in the ponds of the McMurdo Ice Shelf, Antarctica
Authors: Howard-Williams C. , Pridmore R. , Downes M.T. , Vincent W.F.
Published: December 2007

The extensive ablation zone on the McMurdo Ice Shelf (78°S, 165°30′E) contains numerous ponds that are lined with benthic mats of cyanobacteria and associated micro-organisms. The photoautotrophic biomass content of these mats was examined in six contrasting ponds. Particulate carbon contributed only 3.2% of the mat dry weight, with C:N ratios generally less than 20:1. The chlorophyll a content was low relative to carbon (chlorophylla : C<0.01). Analysis of the mats by high performance liquid chromatography [HPLC] showed that the pigment fraction assayed spectrophotometrically as chlorophyll a contained large quantities (up to 70%) of the degradation product chlorophyllide a and the epimer chlorophyll a'. Photosynthetic rates per unit chlorophyll a[HPLC] were extremely slow: <0.1 mg C (mg Chla)−1, less than one tenth the rates recorded in the overlying phytoplankton community. These analyses indicate that in the ice pond benthic mats most of the dry weight is inorganic, most of the organic carbon is non-chlorophyll-containing material, and much of the chlorophyll a is not photosynthetically active. Cold temperatures and the associated low activity of herbivores and detritivores may contribute towards this preservation of inactive chlorophyll a on the McMurdo Ice Shelf, and perhaps in similar benthic mats in the lakes and streams of southern Victoria Land.
Changes in the lipid composition of Antarctic sea-ice diatom communities during a spring bloom: an indication of community physiological status
Authors: Nichols Peter D. , Palmisano Anna C. , Rayner Mark S. , Smith Glen A. , White David C.
Published: December 2007

The lipid composition of natural populations of diatoms in the sea ice at McMurdo Sound was determined during the austral spring bloom of 1985, using and Iatroscan TLC–FID system. The major lipid classes in all samples were polar lipids (including phospholipid, glycolipid and chlorophyll) and triacylglycerol, with lesser proportions of free fatty acids. Total lipid increased through November and early December, reaching a maximum (3300 mg m−2 at Cape Armitage and 1800 mg m−2 at Erebus Ice Tongue) c. one week after the chlorophyll a maxima. This increase was largely attributable to a corresponding increase in triacylglycerol. At the lipid maxima, triacylglycerol/polar lipid ratios in the range 1.0 to 2.5 were observed. The dynamic variations in lipid class abundances indicate that profound changes in the physiology of sea-ice diatoms are occurring throughout the spring bloom. A range of sterols (C26–C30) were detected; 24-methylenecholesterol, brassicasterol and 24-ethylcholesterol were the major sterols at the Cape Armitage and Erebus sites. The similarity of the sterol profiles to those of Antarctic freshwater algal communities strongly indicates diatoms as a more probable source of C29 sterols in the freshwater lakes than cyanobacteria or other algal groups. The hydrocarbons isolated from sea-ice diatoms at all sites were dominated by two unsaturated components, n−C21:6 and a diunsaturated isoprenoid C25 alkene. Until this study, no biological source had been validated for the isoprenoid C25:2 diene, even though it has been detected in many estuarine and coastal sediments.
Mesozoic dolerites from Whichaway Nunataks
Authors: Brewer T.S.
Published: December 2007

The southernmost exposures of Mesozoic dolerites in Coats Land, the Omega dolerites, occur at Whichaway Nunataks. The dolerites are geochemically indistinguishable from the Theron Mountains' dolerites. In both regions high- and low-Ti compositions occur with trace element signatures more akin to island-arc magmas than within-plate tholeiites. From a preliminary Sr isotopic study the Omega dolerites can be classified as Ferrar type. The existence of Ferrar type material in these nunataks suggest that the boundary between the Ferrar and Weddell Sea sub-provinces occurs within the Theron Mountains.
Holocene ice fluctuations on Brabant Island, Antarctic Peninsula
Authors: Hansom J.D. , Flint C.P.
Published: December 2007

Recent geomorphological research in the ice-free areas of West Antarctica and the subantarctic islands has begun to provide an outline glacial chronology that helps our understanding of the late Quaternary history of ice sheets. However, there is a need for detailed studies of the glacial history of the Antarctic Peninsula area and its offshore islands before a general chronology can be fully reliable. In particular, evidence of Neoglacial glacial fluctuations in the area are imperfectly known in spite of work by Sugden & Clapperton (1977) on island groups in the Scotia Sea, Clapperton et al. (1978) on South Georgiaand Clapperton & Sugden (1982) on Alexander Island. The aim of this note is to present data relating to Holocene glacier fluctuations from the hitherto unstuded Brabant Island (64°15′S, 62°3′W).
Field report on combined Anglo–Bulgarian geological studies in northern Alexander Island
Authors: Nell P.A.R. , Kamenov B.K. , Pimpirev C.T.
Published: December 2007

The structural basement of Alexander Island consists of a wide belt of accretionary complex rocks, the LeMay Group (Bum 1984). This is overlain by ?Cretaceous-Tertiary calcalkalinevolcanic rocks (Bum 1981), and intruded by several slightly younger, but related, plutons (Care 1983). The Rouen Mountains batholith is a large group of these plutons which occurs in the northern part of the island.
Low-level wind profiles at an Antarctic coastal station
Authors: King J.C.
Published: December 2007

Wind and temperature profiles in the lowest 2000 m of the atmosphere at Halley (75°35′S, 26°50′W) have been analysed. Surface winds blow most frequently from the sector 090° ± 45° but the 2000 m wind direction is much more evenly distributed and appears to be determined by synoptic-scale pressure gradients. A simple one-dimensional boundary layer model, which includes the effects of stably-stratified air overlying a sloping surface, is able to reproduce some of the features of the observed profiles.
The polar cusp ionosphere: a window on solar wind–magnetosphere coupling
Authors: Saunders Mark
Published: December 2007

The polar cusp ionosphere is an important part of near-Earth space which is best monitored by ground-based observations made in the remote polar regions. Antarctica seems certain to play a key role in its future exploration. The region is characterized by the direct entry of solar wind particles along magnetic field lines projecting to the dayside magnetopause (outer boundary of the magnetosphere). Thus the polar cusp ionosphere provides a splendid window for examining processes transferring solar wind mass and momentum to the magnetosphere. The review will emphasize this aspect of polar cusp ionosphere research, an area where the pace of recent work has been rapid. New results highlight the relevance of both the interplanetary magnetic field direction and changes in solar wind pressure for dynamic effects in the polar cusp ionosphere. These phenomena include surges in plasma flow, auroral activity, magnetic impulses and field-aligned (Birkeland) currents. Among the theoretical advances emerging just this past year are ones for the origin of plasma transport in the dayside polar ionosphere and for the source of the dayside Region 1 and cusp Birkeland currents.
Redescriptions of Cymodocella tubicauda Pfeffer 1887 and Exosphaeroma gigas (Leach 1818) (Crustacea, Isopoda, Sphaeromatidae)
Authors: Brandt Angelika , Wägele J. W.
Published: December 2007

Detailed redescriptions of the poorly known isopods Cymodocella tubicauda Pfeffer 1887 and Exosphaeroma gigas (Leach 1818) are presented in order to allow easier identification of these two species. Similarities to and differences from other species of the genus are discussed.
Survey of algae and other terrestrial biota at Edward VII Peninsula, Marie Byrd Land
Authors: Broady Paul A.
Published: December 2007

The survey concentrated on algal communities but also gathered information on mosses, lichens and microfauna. All 23 nunataks in the Rockefeller and Alexandra mountains (77°00′–78°30′S, 152°–154°W) were visited, including ones both with and without nutrient enrichment from bird colonies. Over 30 species of algae were recorded with Cyanobacteria and Chlorophyta dominant as in other regions of continental Antarctica. Diatoms were not found. The most frequent algae were Cyanothece aeruginosa, Gloeocapsa spp., Oscillatoriaceae, Nostoc sp., Pseudococcomyxa simplex, Stichococcus bacillaris, cf. Desmococcus vulgaris, Prasiola crispa and Prasiococcus calcarius. Although lichens were the most visually prominent vegetation, free-living algae occurred in the widespread ‘non-aquatic’ habitats as epilithic, chasmoendolithic and edaphic communities as well as being epiphytic on the sparse moss cushions. Aquatic habitats were few and there were only three small ponds on or adjacent to nunataks. On ablating ice, cryoconite ponds contained Homoeothrix cf. rivularis, recorded for the first time in Antarctica. Preliminary identifications show 23 species of lichens and six species of mosses. No mites and collembola were seen. Samples contained testate amoebae, ciliate protozoa, rotifers and tardigrades but no nematodes.
Cretaceous angiosperms from an allegedly Triassic flora at Williams Point, Livingston Island, South Shetland Islands
Authors: Rees P.M. , Smellie J.L.
Published: December 2007

A terrestrial sequence on Livingston Island, South Shetland Islands, known as the Williams Point Beds contains a well-preserved, diverse fossil flora previously assigned a Triassic age. Because of their supposed age, volcanic provenance and evidence for active volcanism, the Williams Point Beds have occupied a unique position in Gondwana (pre-Jurassic) stratigraphy in the Antarctic Peninsula region. However, a large new collection of plant specimens obtained at Williams Point has yielded several species of angiosperm leaves, which are abundant and occur at all levels within the Williams Point Beds sequence. Thus, a Triassic age is no longer tenable. On the basis of the plants present and published radiometric ages for associated strata, the Williams Point Beds fossil flora is reassigned to the Cretaceous, and there is some evidence for a more restricted Albian–Cenomanian age. This revision of the age of the Williams Point Beds removes all direct evidence for an active Triassic volcanic arc in the Antarctic Peninsula region.
Isotopic, chemical and crystallographic characteristics of first-year sea ice from Breid Bay (Princess Ragnhild Coast — Antarctica)
Authors: Tison J.-L. , Haren J.
Published: December 2007

A detailed profile of the ice fabric, the deuterium content and the sodium concentration of a 1.64 m long, first-year sea-ice core from Breid Bay, near Syowa station (Antarctica), is described. The core consists mainly of frazil ice (77%), a common feature observed in recent extended studies of the first-year sea-ice cover in the Weddell Sea area. Neither snow ice, nor platelet ice is present. The remainder of the core consists of congelation ice. The typical substructure of ice plates/brine lamellae occurs only at the bottom of the core. Otherwise fine-grained congelation ice is ‘sandwiched’ between layers of frazil. It lacks the intracrystalline substructure but shows a strong textural elongation and c-axis clustering in the horizontal plane. The evolution processes of the first-year sea-ice cover in Breid Bay are analysed. The dynamical component, demonstrated to play a major role in the eastern Weddell Sea, seems to be of minor importance in this area, where thermodynamics satisfactorily explains the isotopic, chemical and textural characteristics of the core. It is proposed that the topmost part of the core consists of frazil ice produced by wind- and wave-induced turbulence. Once a consolidated ice cover is provided, the growth proceeds at a slower rate, through congelation ice formation and frazil ice production, initiated by thermohaline convection processes in the water column. The lower alternate layers of fine grained congelation ice and frazil ice could result from cyclic thermal and salinity regimes at the ice-water interface, connected with the major meteorological events of the year.
Late Jurassic—Early Cretaceous strike-slip deformation in the Nordenskjöld Formation of Graham Land
Authors: Whitham A.G. , Storey B.C.
Published: December 2007

Upper Jurassic–Lower Cretaceous anoxic mudstones and air-fall ashes of the Nordenskjöld Formation are exposed on the eastern coast of Graham Land. Deformation of the strata has a long history spanning dewatering and lithification and was probably produced in a strike-slip tectonic regime. Available evidence suggests the onset of deformation in the region was during Tithonian times. The strike-slip deformation provides further evidence of a plate boundary along the eastern margin of the peninsula during the break-up of Gondwana and the movement of the crustal blocks of West Antarctica. It may also be related to a change in the spreading history of the Weddell Sea region and be the cause of a major facies change from fine anoxic to coarse clastic sedimentation.
The Antarctic drainage flow: implications for hemispheric flow on the Southern Hemisphere
Authors: James Ian N.
Published: December 2007

An Ekman analysis of the surface drainage winds over a sloping ice surface is reported. Ekman pumping by the boundary layer leads to the formation of an upper tropospheric cyclonic vortex above the summit of the ice sheet. The strength and distribution of upper level vorticity is determined by the shape of the underlying ice sheet. The calculation is verified by comparison with the results from a multi-level primitive equation model of flow above an axisymmetric ice sheet. Both models predict that the surface drainage flow will die out on a timescale of a few days, while the upper vortex is predicted to be considerably stronger than observed. Various mechanisms which could lead to the depletion of upper level vorticity, and hence to the retention of a substantial drainage flow, are discussed. It is concluded that disruption of the polar vortex by decaying mid-latitude cyclones, and the consequent export of cyclonic vorticity to lower latitudes, is the most probable mechanism.
Analyses of field moult data: prediction of intermoult period and assessment of seasonal growth in Antarctic krill, Euphausia superba Dana
Authors: Buchholz Friedrich , Morris David J. , Watkins Jonathan L.
Published: December 2007

A technique for moult staging Antarctic krill (Euphausia superba Dana) was used in the analysis of field samples to predict intermoult periods and hence assess growth and the effects of seasonal changes in food availability. The proportion of moulting krill was used, in conjunction with laboratory data on the duration of this phase, to predict the moulting frequency (intermoult period, IMP). The moulting frequency was then combined with appropriate daily growth increments from laboratory study to assess overall growth in the krill sampled. The effects of seasonal fluctuations in food availability on moulting frequency were examined for samples taken at five different locations and times of year. Moulting rate was not linearly related to the availability of phytoplankton, although it is likely that this factor has a marked effect. Similarly, although temperature affects IMP, the data indicate that this is not a simple relationship either. These preliminary data indicate the value of utilizing this technique in the analysis of field samples of Antarctic krill.
The diet of Antarctic fur seals Arctocephalus gazella (Peters) during the breeding season at Heard Island
Authors: Green K. , Burton H.R. , Williams R.
Published: December 2007

Between September 1987 and February 1988, Antarctic fur seals Arctocephalus gazella (Peters) at Heard Island fed mainly on fish with an average 95.2% of scats in monthly collections containing fish remains. Pelagic myctophids constituted more than 50% of fish taken by fur seals at the beginning of the summer season and again at the end when there was an influx of non-breeding male seals. During the middle period from October to December, fish from the surrounding shelf area comprised the bulk of the diet. These included various benthic nototheniid species, the bentho-pelagic ice fish Champsocephalus gunnari Lönnberg and skate (Bathyraja spp.), the latter being found in over 60% of scats in October and November. The population of Antarctic fur seals at Heard Island is increasing at about the same rate as at South Georgia. There the increase is thought to be due to the high availability of krill E. superba, but in the present study no euphausiid remains were found, so the increasing population at Heard Island has been supported on a diet of fish. Whether this population increase can be sustained in future on a diet of fish is arguable. Trial fishing around Heard Island indicates that one of the major dietary items of the seals (C. gunnari) is of probable commercial importance and therefore any plans for the establishment of a fishery on Heard Island grounds must be considered in this light.
Chick feeding in the diving petrels Pelecanoides georgicus and P. urinatrix exsul
Authors: Roby Daniel D.
Published: December 2007

Chick feeding in common diving petrels (Pelecanoides urinatrix exsul) and South Georgia diving petrels (P. georgicus) was studied on Bird Island, South Georgia. Complete chick meals removed from the proventriculus of adults averaged 25.5 g (n = 32) for common diving petrels (17.6% of adult mass) and 23.3 g (n = 24) for South Georgia diving petrels (20.2% of adult mass); neither contained stomach oils. The sum of the positive mass increments during overnight weighings (SUM) averaged 48.6 g for common diving petrel chicks (n = 78 chick nights) and 41.6 g for South Georgia diving petrel chicks (n = 78 chick nights). Average adult feeding frequencies were 0.95 meals day−1 and 0.92 meals day−1, respectively. Relative meal size in diving petrels was similar to that of other procellariiforms, but SUM averaged about twice that of other petrels. The lower conversion efficiency of meals to body mass in diving petrel chicks reflects the absence of stomach oils in the diet. Higher chick feeding frequency and lower variance in SUM are consistent with the hypothesis that diving petrels forage nearshore on reliable food supply compared with other procellariiforms.
Gnathiphimedia mandibularis K.H. Barnard 1930, an Antarctic amphipod (Acanthonotozomatidae, Crustacea) feeding on Bryozoa
Authors: Coleman C. Oliver
Published: December 2007

The family Acanthonotozomatidae is widely distributed, especially in the Antarctic Ocean. Although many acanthonotozomatids are very conspicuous (they are relatively large and often armoured with teeth on tergites and appendages) very little is known about their biology (Just 1978, Coleman 1989).
The diet of the emperor penguin, Aptenodytes forsteri, in Amanda Bay, Princess Elizabeth Land, Antarctica
Authors: Gales N.J. , Klages N.T.W. , Williams R. , Woehler E.J.
Published: December 2007

The diet of the emperor penguin Aptenodytes forsteri (Gray) in Amanda Bay, Princess Elizabeth Land, Antarctica, was studied by analysis of adult stomach contents during part of the chick-rearing period from August to October 1986. The penguins consumed almost entirely fish, mainly Pleuragramma antarcticum (Boulenger) (78% by number and 78% by mass). Other fish species, cephalopods and crustaceans were minor components. These results and those of the only other two, geographically distinct, quantitative studies of the diet of emperor penguins suggest that the diet of this species varies through the effects of local topography and hydrology on prey availability.
Euphausiid life cycles and distribution around South Georgia
Authors: Ward Peter , Atkinson Angus , Peck Julie M. , Wood Andrew G.
Published: December 2007

Euphausiid life histories and distribution in the vicinity of South Georgia were studied from a series of samples taken in April 1980, November–December 1981, and July–August 1983. Size frequency data indicated a two-year life cycle for Euphausia frigida and the possibility of a three-year cycle for E. triacantha. The genus Thysanoessa was represented by a mixture of T. macrura and the dominant T. vicina. A one-year life cycle is proposed for the latter but that of the former is unknown. Spawning in E. frigida and to a lesser extent Thysanoessa spp. commenced as early as July and euphausiid calyptopes were a feature of the plankton for much of the year. E. superba eggs were found in low abundance over the shelf to the north of the island, but no hatched larvae were found. Behaviour patterns such as diurnal and seasonal migration partially confounded attempts to relate euphausiid distribution to environmental features. However calyptopes of most species, were generally more abundant in oceanic water deeper than 500 m and there was limited evidence that in August, E. frigida had commenced spawning in the colder part of the survey area.
A geological reconnaissance of the Radok Lake area, Amery Oasis, Prince Charles Mountains
Authors: McKelvey B.C. , Stephenson N.C.N.
Published: December 2007

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.
A new sedimentological interpretation for part of the Santa Marta Formation, James Ross Island
Authors: Pirrie Duncan
Published: December 2007

The regional geology and lithostratigraphy of the Late Cretaceous strata of north-east James Ross Island have been described by a number of authors (e.g. Olivero et al. 1986, Pirrie 1989). The aim of this short note is to describe a sequence of strata currently assigned to the Santa Marta Formation, and to reinterpret the processes and environments of deposition of this sequence.
Waste disposal–expectations and realities
Authors: Walton D. W. H.
Published: December 2007

Garbage is on everyones' minds at the moment and no more so than in the Antarctic. Thirty years ago it was publicly, legally and scientifically acceptable to burn plastics, to leave rubbish to fall through the ice and to dump hazardous waste into the sea outside the Treaty area. This is no longer the case and the recent turn round in policy poses a number of problems, especially for those countries with long-established stations.
The influence of crude oil on the growth of subantarctic marine bacteria
Authors: Delille D. , Vaillant N.
Published: December 2007

The short term degradation of ‘Arabian light’ crude oil was followed under various seasonal conditions in coastal seawater at Iles Kerguelen. Artificial degradation experiments were carried out in 3 m3 tanks. In situ experiments were conducted in free-floating, semi-enclosed chambers permitting direct contact between the crude oil and the marine environment. Daily sampling allowed a regular survey of the bacterial changes of the oil contaminated seawater. All samples were analysed for total bacteria, heterotrophic viable microflora and hydrocarbon utilizing microflora. At the end of experiments, the remaining oil was carefully collected for rough quantitative estimation of hydrocarbon degradation. All the results clearly revealed a significant increase in the three types of bacterial microflora after the addition of crude oil. However, the data suggest that the initial state of the bacterial communities is important. Thus, the seasonal variations in the bacterial responses to hydrocarbon addition can be related to the differences in the natural bacterial populations involved. In all cases the wall effects observed in batch systems were reduced with in situ incubations.
Diet of the Heard Island cormorant Phalacrocorax atriceps nivalis
Authors: Green K. , Williams R. , Woehler E.J. , Burton H.R. , Gales N.J. , Jones R.T.
Published: December 2007

The diet of Heard Island cormorants was investigated by examination of casts over three summer seasons. The diet was composed mainly of benthic organisms, with polychaetes being the most common prey for the greater part of the population. Fish were taken commonly only by the small breeding population at the western end of the island, whereas elsewhere only 22% of casts contained any fish remains at all. The diet is therefore different from that reported for Phalacrocorax atriceps at other localities.
A new Triassic vertebrate fauna from Antarctica and its depositional setting
Authors: Hammer William R. , Collinson James W. , Ryan III William J.
Published: December 2007

A new fauna of late Early to early Middle Triassic vertebrates has been found in the upper member of the Fremouw Formation in the Beardmore Glacier area of Antarctica. It includes Cynognathus, a kannmeyeriid, and other therapsid (mammal-like) reptiles representing new, more derived genera of carnivorous and gomphodont cynodonts. New genera of temnospondyl amphibians belonging to the capitosauroid evolutionary complex also occur. The unusual abundance of well-preserved amphibians may offer new insights concerning the evolution and distribution patterns of early Mesozoic temnospondyls. These fossils represent only the second terrestrial vertebrate fauna from the mainland of Antarctica. The fossils occur on a prominent sandstone platform, which represents part of the exhumed channel of a braided stream deposit. The platform is over 200 metres above the well-known Lystrosaurus fauna of the lower Fremouw Formation. The locality is near the axis of a major foreland basin that paralleled the present trend of the Transantarctic Mountains. Conditions of rapid subsidence and aggradation of fluvial units were ideal for the preservation of vertebrate faunas.
Surface layer ozone above the Weddell Sea during the Antarctic spring
Authors: Yurganov L.N.
Published: December 2007

Ozone concentrations in the atmospheric surface layer above the Weddell Sea during the Antarctic spring season of 1989 varied significantly. Lower levels of ozone were associated with colder Antarctic air masses and higher values with warmer mid-latitude air. The lowest ozone concentration (1 to 2 ppbv) was measured in the centre of a low pressure system. A definite diurnal variation of tropospheric ozone observed during clear days with low total ozone amount (177 matm cm) may be interpreted as a consequence of the occurrence of photochemical reactions under conditions of increased ultraviolet solar radiation.
International collaboration in Antarctic medical research
Authors: Lugg D.J.
Published: December 2007

Antarctica has been an ideal continent for international scientific collaboration. The success of SCAR and its multinational core Working Groups, and Groups of Specialists in fostering such collaboration is recognized internationally.
Feeding selectivity in Notothenia neglecta, Nybelin, from Potter Cove, South Shetland Islands, Antarctica
Authors: Barrera-Oro E.R. , Casaux R.J.
Published: December 2007

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.
The deep sea isopod genus Echinozone Sars, 1897 and its occurrence on the continental shelf of Antarctica
Authors: Brandt Angelika
Published: December 2007

Echinozone quadrispinosa (Beddard, 1886) is reduced to synonymy with E. spicata (Hodgson, 1910). A key is given to the four Antarctic species together with biogeographical information.
Tests of Antarctic soils for insect parasitic nematodes
Authors: Griffin Christine T. , Downes M.J. , Block W.
Published: December 2007

Nematodes of the families Heterorhabditidae and Steinernematidae are obligate parasites of a wide range of insects (Poinar 1979). The third stage juvenile of these nematodes is a non-feeding infective form which carries symbiotic insect-pathogenic bacteria (Xenorhabdus spp.) in its intestine. Under favourable conditions the juveniles can survive for months in the soil. They are attracted to and enter insects. After invading the haemocoel they release the symbiont. The bacteria multiply, kill the host by septicaemia, and provide suitable conditions for nematode growth and reproduction. After one to two weeks, the newly formed infective juveniles leave the cadaver and seek new hosts.
Equivalent ionospheric currents above Antarctica during the austral summer
Authors: Papitashvili V.O. , Feldstein Ya.I. , Levitin A.E. , Belov B.A. , Gromova L.I. , Valchuk T.E.
Published: December 2007

A regression analysis was carried out between the ground-based geomagnetic data from the southern polar regions (above −55° corrected geomagnetic latitude) and the interplanetary magnetic field (IMF) components in the geocentric solar-magnetospheric co-ordinate system and solar wind (SW) parameters. Hourly mean values of the geomagnetic field horizontal components H and D from 20 Antarctic observatories and automatic stations of 1978–80 and 1983–84 were examined. Regression coefficients were used as geomagnetic perturbation vectors which were rotated 90° clockwise to plot the equivalent current vector patterns in the “corrected geomagnetic latitude-magnetic local time” co-ordinates. The results which are described in the paper reflect geomagnetic phenomena associated with the IMF and SW parameters for the austral summer season only (November, December, January, February). It was found that, in general, global characteristics of the ionospheric convection patterns agree well for both hemispheres. Geomagnetic variations, which are generated by the interaction of the SW plasma and frozen-in IMF with Earth's magnetosphere, represent three types of equivalent current systems: a) two-vortex system with transpolar current from nightside to dayside, controlled by the “quasi-viscous” interaction and southward IMF; b) zonal current system, controlled by the azimuthal IMF; and c) two-vortex system with transpolar current from noon to midnight controlled by the northward IMF. The southern polar cap (above −75°), which was more densely packed with automatic magnetometers than the northern cap, permit us to investigate the fine structure of the high-latitude current systems in detail.
Attendance behaviour of Antarctic and subantarctic fur seal females at Marion Island
Authors: Bester Marthán N. , Bartlett Peter A.
Published: December 2007

The female attendance behaviour of Antarctic fur seals (Arctocephalus gazella) and subantarctic fur seals (A.tropicalis), which breed sympatrically on subantarctic Marion Island, was investigated. Over the same period after the breeding season, the mean duration of feeding trips to sea, and percentage of time spent at sea, did not differ significantly between lactating females of the two species. The difference in mean duration of shore visits was significant and the longer onshore attendance of A. tropicalis probably related to the lower demand by their pups which grow at a slower rate. The subpolar maternal adaptations of A. gazella were unchanged under the more temperate environment at Marion Island, and it remains to be established unequivocally whether conditions there are limiting to the species.
Pre-caldera Pyroclastic deposits of Deception Island (South Shetland Islands)
Authors: Martí J. , Baraldo A.
Published: December 2007

The youngest pre-caldera volcanism of Deception Island is represented by a thick sequence of subaerial pyroclastic deposits which has been grouped as the Yellow Tuff Formation. Most of these deposits were related to the explosive activity of a central vent which was destroyed during the formation of the caldera. Two members can be distinguished in this formation. The lower member is mainly composed of 1 to 12 m thick massive pyroclastic flow deposits with interbedded air-fall and surge deposits. The upper member is in stratigraphical continuity with the lower member and consists of base surge deposits with minor air-fall and thin pyroclastic flow deposits. The pre-caldera deposits have undergone a palagonitic alteration which produced crystallization of smectites, Fe-oxides, zeolites and calcite.
If you have a set of rocks, what should you call them?
Authors: Elliot D. H.
Published: December 2007

By tradition, palaeontologists use the Linnaean scheme in the classification of fossil organisms. But what about the naming of rocks or sequences of rocks in which those fossils occur; or what about those rocks which never had even a whiff of an organism at the time of their formation? My favourite rock name is Charnockite, named from the tombstone of Job Charnock, an employee of the East India Company and the founder of Calcutta, who by legend “after the death of his wife, every year sacrificed a cock to her memory in the mausoleum” (Dictionary of National Biography, 1990) until his own death in January 1693. But it is not individual rock types that form the subject of this note; rather it is larger sets of related rocks, whether sedimentary, igneous, or metamorphic in origin. Description of related sets of rocks requires schemes of nomenclature that are widely accepted and used; these, in themselves, must be firmly based on an internationally agreed set of principles, and there must be wide dissemination of additions to the nomenclature.
Consumption of Antarctic krill by Minke whales
Authors: Armstrong A.J. , Siegfried W.R.
Published: December 2007

The consumption of Antarctic krill (Euphausia superba) by an “average-sized” (male 6994 kg; female 8249 kg), sexually mature Minke whale (Balaenoptera acutorostrata) was estimated, from stomach capacity, ingestion rate and respiratory allometry methods. Estimates obtained from the stomach capacity and respiratory allometry methods differed by 17%–23%. An “average-sized” male Minke whale consumes 37.2 t of krill during a 90-day stay, and an “average-sized” female Minke whale consumes 56.2 t of krill during a 120-day stay, in Antarctic waters during the austral summer. It is estimated that the Minke whale population in the Antarctic (60°S and higher) consumes 35.5 × 106 t of krill annually.
The diet of Antarctic petrels, cape petrels and southern fulmars rearing chicks in Prydz Bay
Authors: Arnould John P.Y. , Whitehead Michael D.
Published: December 2007

The breeding season diet of the three surface-nesting petrel species on the Rauer Islands, Prydz Bay were examined. The stomach contents of cape petrel (Daption capense), Antarctic petrel (Thalassoica antarctica), and southern fulmar (Fulmarus glacialoides) were sampled by collecting regurgitates and by stomach flushing during the 1987/88 early chick-rearing period. Pleuragramma antarcticum and Euphausia superba dominated the diets of all species. By mass they constituted 78% and 22% of Antarctic petrel diet, 63% and 36% of southern fulmar diet, and 14% and 85% of cape petrel diet respectively. P. antarcticum increased in importance in the diet of Antarctic petrels during the course of the study, while E. superba became increasingly important in the diets of southern fulmars and cape petrels. Previous studies conducted during incubation consistently reported the diets as comprising chiefly cephalopods and euphausiids, whilst studies during chick-rearing have reported fish and euphausiids dominating, and very little cephalopod material.
The bivalve Aulacomyella from the Early Tithonian (Late Jurassic) of Antarctica
Authors: Kelly Simon R.A. , Doyle Peter
Published: December 2007

The bivalve Aulacomyella is described formally from Tithonian deposits of the Antarctic Peninsula region for the first time. Two species are recognized. A. willeyi Kelly sp. nov. was collected in situ from the Nordenskjöld Formation, Longing Gap on the east coast of Graham Land, and in clasts reworked into Cretaceous glide block deposits on James Ross Island. A. cf. problematica Furlani is recorded from the Himalia Ridge Formation, Fossil Bluff Group, Alexander Island. These Antarctic records are the first published systematic descriptions of the genus from the Southern Hemisphere. Together with Mexican and Turkish records, they represent the last known occurrences of this genus. Globally the genus is particularly abundant during the Kimmeridgian and Early Tithonian stages and is therefore of value as a biostratigraphic indicator. It was almost certainly an epibyssate suspension feeder, although the precise palaeoecological setting for Aulacomyella is uncertain. It normally occurs in black shales or mudstones. The most likely life habits were either living epifaunally on the sea floor, where it bloomed under episodic dysaerobic conditions in an otherwise anaerobic environment, or pseudoplanktonically infesting floating sea weeds etc. Of these hypotheses the former is preferred here.
Antarctic politics and Antarctic science — are they at loggerheads?
Authors: Heap John A
Published: December 2007

“Antarctica shall be used for peaceful purposes only …… Freedom of scientific investigation and co-operation toward that end …… shall continue, subject to the provisions of the present Treaty.”

These are the fundamental objectives of the Antarctic Treaty as expressed in Articles I and II. What
follows in the Treaty, and in most of the many “Recommendations” to the Governments of Antarctic
Treaty Consultative Parties (ATCPs), is aimed at securing these objectives by the creation of a
framework of law. Unusually for a system of laws, most of this legal framework is hortatory rather
than mandatory in character - it cajoles rather than orders. Perhaps not surprisingly this has given rise
to damaging suggestions about its ability to provide adequate protection for the Antarctic environment.
The response of the ATCPs to this criticism has been to embark on a review of existing Antarctic law,
to make it more consistent, reduce overlaps and more especially, make much of it mandatory. This
process began at the XIth Special Antarctic Treaty Consultative Meeting in Chile last November.
Since it aims to provide greater clarity, accessibility and certainty in the law, it must be welcomed.
But within these admirable objectives a prospect of loggerheads begins to loom.