Studies on southern elephant seal (Mirounga leonina) were carried in Admiralty Bay (King George Island, South Shetland Islands) in summer 1978/1979. In the whole region of Bay the maximum number of 964 elephant seals was noticed on 5 Jan. 1979. The biggest nonbreeding colonies were observed in the mouth region of the Bay. In December the males made up 74% of the whole population, their number decreased to 17% in February. Most individuals belonged to the IV class of age (6—9 years old). Introductory observations of 24 h activity indicates four peaks of activity in the groups observed on the coast. The type of weather has influenced the activity of these groups and the frequency of descending to the sea.

Studies on performance capacity and selectivity of trawls used for industrial fisheries of krill (Euphausia superba) were carried out on the research vessel r/v „Profesor Siedlecki". It has been ascertained that performance capacity of the proposed trawl is about 0.86 and that chiefly small, 22—26 mm-long, krill specimens are passing through the trawl segments made of 12 mm-meshed fabric. This has an essential effect on the age-size structure of caught specimes of krill. It has been stated that the insets of less than 10 mm-mesh fabric in the bags and less than 12 mm-mesh fabric in the bellies of the trawl are practically inexpedient.

Twelve mineral elements and total ash were examined in regard to the possible use as the estimators of digestibility of natural food in Antarctic seals. Four of them: phosphorus, calcium, copper and zinc have proved to give most reliable results. The estimated total dry mass and organic matter digestibilities of fish food in Weddell seals (Leptonychotes weddelli (Lesson)) averaged 82 and 91%, while the corresponding values for krill eaten by crabeaters (Lobodon carcinophagus (Hombron and Jaequinot)) and leopard seals (Hydrourga leptonyx (Blainville)) reached approximately 87 and 91%, respectively.

Total toxicity of two types of mineral oil (from Zakum and Kuwait) was determined with respect to hydrobionts of the Antarctic ecosystem. Crustacean — Euphausia superba proved to be sensitive to hydrocarbon pollution of the sea environment (LC50 x 48 h-1 = 7.62 ppm). Fish — Notothenia rossi marmorata showed much lower sensitivity.

The measurement of SO2, and fluorine compounds concentrations in the air at 8 points on the King George Island, South Shetland Islands, were done in January and February 1979. The received values were similar to the ones for regions recognized as the world background areas. The activity of the Polish Antarctic Station did not influence the air pollution status neither in its surroundings, nor in penguins colonies and extinct volcano areas on Penguin Island.

Studies were performed on two species of fish from family Chaenichthyidae and on seven species of family Nototheniidae. Statistical analysis of the subcutaneous and trunk muscle fibres diameter from the trunk and tail area allowed to state that the thickness of these fibres is inversely proportional to the metabolism level of fish. The inter-species similarities were found, but they were not found within families, if their representatives differed in metabolic level.

The arylsulphatase activity (E. C. 3. 1.6. 1.) was compared in different species ol Antarctic mammals, birds of the genus Pygoscelis, fish of the genus Notothenia and two crustaceans oi the genus Euphausia. The role of arylsulphatase in the hydrolysis of sulphate phenol esters was pointed out. Considerable differences were observed in the arylsulphatase activity both within genera and species. But no differences in the activity of the enzyme examined were observed in relation to the sex or maturity stage of gonads of chosen Antarctic animals. The activity of arylsulphatase from liver and hepato- pancreas homogenates оf Antarctic animals was lower than the activity of this enzyme in similar animals of the temperate zone.

In the austral summer of 1977/78 phytoplankton populations in Ezcurra Inlet, Admiralty Bay, reached maximum abundance at the end of February; two smaller peaks of growth occurred in January. Flagellates and "monads" were dominant in the plankton, except two days in December, when diatoms were prevalent. Thalassiosira untarctica and a few species of the genera Nilzschia and Chaeloceros were the major diatoms during the summer. Several other diatoms. Corethron criophilum. Eucampia bulaustium. and Rhizosolenia spp. together with the all-summer dominants, contributed to the diatom peak in December, following the breaking of ice. Algal peaks always followed periods of calm days and stable atmospheric pressure; the increased stability of the water column at such times appears to be the factor determining the onset of the periods of phytoplankton maxima. Decline of algal peaks could be largely attributed to grazing by Euphausia superba and E. crystallorophias.

Studies conducted between December 20. 1978 and February 20. 1979 on Arctowski Station show that daily sums of total radiation ranged from 165.5 to 834.5 mWhr x cm2. Maximal mean hourly radiations were recorded from 12 to 14 hours (39.7—72.4 mWhr x cm2).

It appears from the analysis of the chemical composition of macroalgae of the Antarctic: Adenocystis utricularis and Himantothallus grandifolius (brown algae), Leptosomia simplex (red algae) and Monostroma hariotti (green algae) that the examined algae, brown algae in particular (mainly Adenocystis utricularis), are rich in mineral components, primarily: sodium, potassium, hologens, and structural polysaccharides. Organic substances, such as: proteins, amino acids, lipids, fatty acids, saccharides reduction, chlorophylls and carotenoids, occur in the analysed algae in quantities much smaller in comparison with taxonomically similar macroalgae derived from marine environment having more favourable hydrochemical and climatic conditions.

The occurrence of 18 species of algae was stated in the investigated region. Among them the following were predominant: Himantothallus grandifolius, Desmarestia menziesii, Cystosphaera jacqninotii, Ascoseira mirabilis. Leptosomia simplex. Adenocystis utricularis. Monostroma hariotii, Iridaei: obovata, Hildenbrandia lecunnellieri, Plocamium coccineum and Phycodrys antarctica. Vertical stratification of the distribution of three singled out communities of algae was observed downwards to the depth of 90 m, which is the limit of the occurrence of the algae in the Bay. The process of decomposition depends on the place where it occurs, the kind of the thalluses and the season of the year. The quickest decomposition of algae was observed on the shore, in the summer and spring. The total quantity of algal matter washed ashore along 15.8 km of the coast line of Admiralty Bay, during the period between February and October 1979, was estimated at 279 metric tons of dry weight matter. From this quantity, in result of decomposition of the algae on the shore, 75 tons of the matter were released during an average time of 12 days. The remaining 204 tons of partially decomposed algal matter are driven by winds farther inshore or into the waters of the Bay or remain ashore among the stony rubble.

General meteorological conditions in the Admiralty Bay in 1978 did not deviate from those of many years. The data for 1978 were used to analyse the co-occurrence of four most perceptible meteorological parameters: temperature, air humidity, wind speed and precipitation. In summer these elements occurred simultaneously only in 1 — 2 intervals of values, in winter their occurrence within individual intervals was less numerous, but covered more of them.

This study gives an analysis of the variation of main meteorological parameters on the Station Arctowski in the time from December 1979 through March 1980 — the summer season of the IV Antarctic Expedition of the Polish Academy of Sciences. Characteristics of wind speed and direction, of air temperature, atmospheric pressure, precipitation, cloudiness, soil temperature at the station and surface water temperatures of the Admiralty Bay are based on the standard synoptic observations.

On the basis of surface pressure analyses covering the area of south-west Atlantic, maps of monthly mean pressure fields for the period from March to December 1979 were drawn. In order to accentuate the dynamics of pressure processes, maps of standard deviation as well as of the skewness coefficient of the values forming the pressure field were also prepared. Apart from this, the variation of pressure in the particular points of the field in the months considered, was discussed. Attention was drawn to the distinct quasi-periodicity, dependent on location of the given point.

During geomorphologic mapping of northern seashore of Hornsund (Spitsbergen) a geomorphologic map of Revdalen and Fuglebergsletta was prepared in the scale of 1: 10 000. Distinct outwash routes and a moutonnee area was noted to the south of Rewatnet; at the same time, the destroyed marine terraces in the upper part of the valley and an occurrence of a ground moraine there, prove a Holocene glacier advance in Revdalen (about 2 400 years B. P.). The glaciers of that time slightly overcrossed a zone of the present southern limit of the Rev Lake but they did not fill entirely the middle part of the Revdalen.

During the expedition "Spitsbergen 1979/80" the authors prepared a geomorphologic map of the area to the north of Hornsund, between the Torell Glacier and the Treskelen Peninsula. Fifteen raised marine terraces were distinguished. Basing on field morphometric sections, quite a detailed distribution of the terraces at a seaside plain and in side valleys was noted. Also, the previous Polish studies over this part of the Svalbard Archipelago were taken into account. The terraces occur at the following altitudes: 220—230 m, 200—205 m, 180—190 m, 100—115 m, 80—95 m, 70—75 m, 60—65 m. 45—46 m, 40 - 46 m, 32—35 m, 22—25 m, 16—18 m, 8—12 m, 4.5—6 m and 2 m a.s.l. (Figs. 2—5). The terraces are not evenly distributed and they possess a varying structure. The authors, due to absence of other chronologic evidence but on the ground of a morphologic analysis and radiocarbon data (presented by Birkenmajer and Olsson 1970) suppose that only the lowest terraces have been formed in a postglacial period.

Investigations were carried out in the regions of the Hornsund Station, Spitsbergen at summer 1979. The aim of the studies was to determine the effect of the Station on the natural environment around the Station. After taking an inventory of the sources of pollution and in result of the determination of the range of the pressure of anthropogenic factors the whole area under degradation was divided into three parts: an area without possibilities of recultivation, a devastated area and an area of normal natural environment. It was found thąt the main source of the contamination of tundra are fuels derived from mineral oil. The distribution of fuel concentrations in the soil corresponds to the direction of the slope of the ground and the flow of the surface waters. Mechanical transformation of the surface of the tundra is also an outcome of the degradation.

The post-sedimentatal deformations on the line of moraine clay and sea gravel are described as well as their genesis. When the frozen ground thaws in summer these sediments form under the influence of water a system having unstatic density layering. The influence of several factors on the deformation has been described.

The contribution of mercury and iodine in the particles of atmospheric aerosol and in the surface film of marine waters were estimated in the region of Admiralty Bay, King George Island, South Shetlands. Aerosols were collected with microscopic copper grids and on fibrous filters of microsorban type, and surface film with glassy slides. The obtained data are significant as natural background data.

The analyzed ridges posses a varying morphology and dimensions. They are composed of rocky blocks of local origin only. The blocks are chaoticly arranged although a position transversal to a morphologic axis of the ridge predominates. The ridges occur mainly in places where distinct structural loosenings of the mountain massifs are noted, at the foot of fresh slopes. They define the periods when rockfalls were most intensive. The authors found the subslope ridges to be the nival moraines.

Ice-cored moraines are the only accumulation forms of Antarctic ice-sheet in the contact zone with Bunger Hills. Their longiness ranges from 3.5 km to 250 m, they are from 300 m to 30 m wide and their elevation oscillates between 10 and 5 m. A thickness of moraimc cover which lags the ice-core is changeable in the limit of 1 m. A process of decay of ice-cores, leading to deformations of their moraines, plays a small part up to now. It is caused a dry climate, probably, which was not favorable for the release and the work of melted waters in a large scale. The weak separation of ice-cored moraines results from a small amount of morainic material transported to the front of ice-sheet, probably as the ice-sheet is almost motionless. The granulometric analysis of morainic sediments shows their bad segregation.