Two new species of desmosomatid isopods, Eugerdella margaretae sp. n. and Eugerdella celata sp. n. are described from Admiralty Bay, King George Island, South Shetlands. Information is added to the original description of Eugerdella falklandica (Nordenstam, 1933) based on re−examination of the holotype. Both new species are similar to E. falklandica, for example by the body shape, the shape of pleotelson and presence of rows of four horn−like spines on the head. They are distinguished from E. falklandica by the number of setae on pereopod articles. Eugerdella celata sp. n. is distinguished by the presence of ventral spines on pereonites 1–4
The results of investigations on the coccidian parasites of three species of penguins ( Pygoscelis antarctica , P. papua and P. adeliae ), nesting at Livingston and King George Island (South Shetland Islands, the Antarctic) are presented. Three coccidian para− sites: Eimeria pygosceli Golemansky, 2003, Eimeria sp. and Isospora sp. were identified in faecal samples from 360 examined birds. The total prevalence of coccidian parasites was high: about 35% in all of examined penguins. No host specificity was observed. It is attributed due to the close phylogenetic relations, common habitats and nesting territories, similar feeding and reproductive biology of the three penguin species. In more than 20 specimens of investigated penguins a high intensity of oocysts in their guano was observed (80–220 oocysts in one microscopic field at magnification of 150×) an indirect indication of the negative role of the coccidian infections on penguin populations.
Net of temperature, salinity and dissolved oxygen content measurements were made in situ at 24 stations in Admiralty Bay with the use of automatic analyzer Martek MK IV. Results proved a presence of two water masses located horizontally one over the other, with the boundary at depth of 15—35 m. The main, lower mass consists of homogenous waters inflowing from the Bransfield Strait. The upper, thin and much differentiated layer is formed through interaction of the main underlying water mass with meltwaters from glaciers and sea ice. It is probably formed along the whole archipelago and carried by surface currents into the bay where it is subjected to further modifications. Local salinity and temperature extremes are associated with glacier water runoff; local dissolved oxygen maxima seem to be connected with phytoplankton distribution. Strong currents occurring in te bay due to water circulation may cause local, short term and sometimes considerable fluctuations in values of parameters recorded at individual stations.
Populations of Antarctic hairgrass Deschampsia antarctica Desv. from King George Island exhibit variation in many traits. The reason for that is not evident and could be addressed to variable environmental conditions. Obviously, phenotypic variation could be due to stable or temporal changes in expression pattern as the result of adaptation. Stable changes could be due to mutations or site DNA methylation variation that modified expression pattern. Recently, metAFLP approach was proposed to study such effects. A variant of methylation sensitive AFLP (Amplified Fragment Length Polymorphism), based on the isoschizomeric combinations Acc65 I/ Mse I and Kpn I/ Mse I was applied to analyze the sequence and site DNA methylation differences between two D. antarctica populations exhibiting morphological dissimilarities. Both DNA sequence mutations and site methylation pattern alternations were detected among and within analyzed populations. It is assumed that such changes might have originated as the response to environmental conditions that induced site methylation alternations leading to phenotypic variation of D. antarctica populations from South Shetland Islands.
In the material of nearly 2000 individuals of Asteroidea collected in Admiralty Bay, the largest bay of the South Shetlands, 36 species were determined, enriching the list of hitherto known asteroid species of this basin by 17 taxa. One of them, Peribolaster macleani, is recorded for the first time in Western Antarctic. The most frequent and abundant asteroids of Admiralty Bay were Odonlaster validus, Psilaster charcoti, Bathybiaster loripes obesus and Diplasterias brucei. The bathymetric and geographic distribution of all species are discussed.
Properties of a snow cover in the vicinity of Arctowski Station, King George Island (West Antarctica) were studied in 1991. Variations of snow quality and physical transformations were analysed against changes of atmospheric parameters, basing on water equivalent index and repeatable examination of snow pits. Essential dependence of snow cover distribution and snow structure from local climatic features and terrain morphology was found. Thawing occurs in the whole mass of snow, with its contribution of both liquid and gas water phases.
Temperature of superficial water in the Ezcurra Inlet was measured from March 1989 to February 1990, with a use of a mercurial thermometer with accuracy +0.1°C. Temperature was measured usually once a month at selected points. Influence of various factors on temperature of superficial water was preliminarily analysed. Basing on these results, temperature distribution in the mentioned area was determined. Mean yearly temperatures for each station, average space temperatures on measurement days and mean yearly temperatures for the whole area of the Ezcurra Inlet were calculated.
In the Admiralty Bay 36 taxa of macroalgae were found. Among them the most common were: green alga Monostroma hariotti, red algae — Georgiella confluens, Iridaea cordata, Leptosarca simplex and Plocamium cartilagineum, and brown algae — Adenocystis utricularis, Ascoseira mirabilis, Desmarestia anceps, D. ligulata, D. menziesii and Himatothallus grandifolius. The bottom surface covered with macroalgae (in the orthogonal projection on the water mirror) amounts to 36,9 km2 i.e. 31% of the total surface of the bay. In the central part of the Admiralty Bay the macroalgae aggregations occupy 35% of the bottom surface and are most abundant in respect to the density, biomass, number of taxa (33) and diversity. There were distinguished 3 zones of vertical distribution of phytobenthos in the Admiralty Bay. I zone includes the macroalgae in epilittoral, littoral and sublittoral to the depth of 10 m. II and III zones are situated in sublittoral within the depths of 10 60 m and 60—90 m, respectively. Each zone is characterized by the occurrence of different aggregation of taxa. The bottom areas belong to I, II and III zone of macroalgae make 28%, 64% and 8% respectively in relation to the total surface of phytobenthos in the bay. Vertical range of the distinguished zones varies in different parts of the Bay in relation to the bottom character. Macroalgae occur down to the depth of 90 —100 m. The composition of the macroalgae flora evidences for its transitory character between the benthic subantarctic flora and that of the areas adjacent to the Antarctic continent.
A collection of 15 283 individuals of tanaidacean crustaceans was gathered by successive Polish Antarctic Expeditions in the years 1977-1993 in Admiralty Bay (King George Island, South Shetland Islands). Twelve species belonging to three families are identified in this study. The material is clearly dominated by Nototanais antarcticus (Hodgson, 1902); other common species were Nototanais dimorphus (Beddard, 1886) and Peraeospinosus sp. A. The highest density of tanaids was over 140 000 specimens m-2 , occuring on a muddy bottom in Herve Cove lagoon.
The climatic change on King George Island (KGI) in the South Shetland Islands, Antarctica, in the years of 1948–2011 are presented. In the reference period, a statistically significant increase in the air temperature (0.19 ° C/10 years, 1.2 ° C in the analysed period) occurred along with a decrease in atmospheric pressure (−0.36 hPa/10 years, 2.3 hPa). In winter time, the warming up is more than twice as large as in summer. This leads to decrease in the amplitude of the annual cycle of air temperature. On KGI, there is also a warming trend of daily maximum and daily minimum air temperature. The evidently faster increase in daily minimum results in a decrease of the diurnal temperature range. The largest changes of air pressure took place in the summertime (−0.58 hPa/10 years) and winter (−0.34 hPa/10 years). The Semiannual Oscillation pattern of air pressure was disturbed. Climate changes on KGI are correlated with changing surface temperatures of the ocean and the concentration of sea ice. The precipitation on KGI is characterised by substantial variability year to year. In the analysed period, no statistically significant trend in atmospheric precipitation can be observed. The climate change on KGI results in substantial and rapid changes in the environment, which poses a great threat to the local ecosystem.
Mid-winter rapid rise of temperature in the vicinity of Arctowski Station, King George Island (West Antarctica) was studied in 1991. Depending on circumantarctic migration of cyclones, sudden drop in air pressure and foehn-like phenomenon intensified by local topography occurred. Two such events are described on May 13 and June 28, against meteorological conditions during autumn and winter. Extreme intensification of morphogenetic processes caused degradation of a snow cover, immense meltwater discharge, radical transformation of slopes, effective aeolian activity and dynamic modifications in a sea-shore zone.
The environments of inlets, coves and lagoons varies widely. Climate warming has lead to retreat of glaciers directly entering the sea. In lagoons this is accompanied by exposure of an uncolonized substratum. Colonization processes in these lagoon appear to describe processes which have previously occurred in bays and fjords of glacial origin in the South Shetlands.
Cumacean crustaceans found in 188 qualitative and quantitative samples of zoobenthos collected in Admiralty Bay (King George Island, South Shetlands) by successive Polish Antarctic Expeditions in the years 1977 — 1989 were studied. In over 3000 individuals of these crustaceans 12 taxa were recognized. Eudorella splendida clearly dominated the material. Other common species were Campylaspis maculata and Vaunthompsonia inermis. The highest cumacean density amounted to 2618 ind.m-2 . Clear differences were observed between cumacean faunas of small grain sediment (muddy Ezcurra Inlet) and of mixed, coarser sediments (central part of Admiralty Bay with sand, gravel and mud). The dominance of Eudorella splendida was strongly marked in shallow Ezcurra Inlet whereas in deeper central part of Admiralty Bay the cumacean fauna was much more diversifield.
The frequency of wind occurrence at sectors each 30° as well as mean air temperature at particular wind direction were accounted for the warmest and the coldest year of the investigation period 1978—1987 at Polish Antarctic „Arctowski" Station. The effect of orography on wind direction and air temperature was determined. A great rate of dependence of air temperature and wind direction upon atmospheric circulation type was found. High air temperature at the winds from 300° and 330° directions is related both to the kind of air mass and foehn phenomena.
Observations from 1978—81, 1983 and 1985 collected at the Polish Polar Arctowski Station (King George Island, South Shetland Islands) were used to calculate frequencies of wind directions in 30° sectors and mean air temperatures observed at each wind direction. Results reveal that all over the year the warmest air masses flow onto the South Shetland Islands from the northwest while the coolest ones from the southeast and east.
Contents of PCBs was investigated using the gas chromatography method in the tissue of four Antarctic migratory birds: Oceanites oceanicus, Larus dominicanus, Catharacta skua and Sterna vittata, and the three penguin species: Pvgoscelis adeliae, P. papua and P. antarctica. Samples were collected at King George Island in February 1978 and, for comparison, in March 1983. The highest PCBs content was recorded in the adipose tissue of O. oceanicus and C. skua (15.7 and 1.2 ppm). Differences in the content of these compounds in the tissue of various penguin species in 1978 was observed. The mean cumulation level of PCBs in the adipose tissue of penguins was higher in 1983 than in 1978. Differences in the level of PCBs contents in the tissue of migratory birds were related to their winter migrations to areas polluted to various degress with PCBs remains. A tendency to the increase of the contamination of penguin tissues with PCBs was observed. This tendency was related to the increase of vhe pollution of the Antarctic environment with these compounds.
Net phytoplankton cell numbers in 50 m water column of Admiralty Bay ranged between 0.2 x 10 5 x m-2 on 24 August 1990 and 2.3 x 10 7 x m-2 on 15 November 1990. Cluster analysis has confirmed the presence of two groups of samples: spring and summer ones (October to April), rich in cells and in species, and, on the other hand, winter samples (June to August) impoverished in algae. Spring and summer fluctuations of diatoms were mainly due to Corethron criophilum, Rhizosolenia alata and its varieties, R. hebetata f. semispina, Thalassiosira spp., Chaetoceros spp., and Nitzschia spp. (Fragilariopsis and Pseudonitzschia groups). The abundance and succession of species in Admiralty Bay reflect seasonal differences in diatom growth; they also reflect mixed populations of the Weddell and Bellingshausen seas entering Admiralty Bay via Bransfield Strait. Striking poverty of algae in some summer samples can most likely be attributed to zooplankton grazing.
Luticola muticopsis is a characteristic species of polar and subpolar regions. Its morphological variability is not yet precisely described. In the investigated population the cells from capitate to shortened, flat rounded tips were observed. The range of dimensions of specimens was 8.8-40.6 μm x 5.5-17.6 μm, striae 11-22/10 μm; this range considerably exceeded that found in holotype diagnosis.
The lithospheric transect South Shetland Islands (SSI) — Antarctic Peninsula (AP) includes: the Shetland Trench (subductional) and the adjacent portion of the SE Pacific oceanic crust; the South Shetland Microplate (younger magmatic arc superimposed on continental crust); the Bransfield Rift and Platform (younger back-arc basin); the Trinity Horst (older magmatic arc superimposed on continental crust); the Gustav Rift (Late Cenozoic) and James Ross Platform (older back-arc basin). Deep seismic sounding allowed to trace the Moho discontinuity at about 30 km under South Shetlands and at 38—42 km in the northern part of Antarctic Peninsula (Trinity Horst), under typical continental crust. Modified crust was recognized under Bransfield Strait. Geological interpretation based on deep seismic refraction and multichannel reflection soundings, and surface geological data, is presented.
In the material collected in 26 stations along the course of three creeks in the vicinity of Polish Antarctic Station 183 taxa of algae have been identified: 25 of Cyanophyta, 123 of Bacillariophyceae, 2 of Xanthophyceae, 2 of Chrysophyceae and 31 of Chlorophyta. The highest species diversity was found in the algal community in Creek II (132 taxa), the second place was occupied by the "Petrified Forest Creek" (97 taxa), and the least diversified algal community was that from the "Ornithologists' Creek" (73 taxa).