Polish Polar Research

In 1979 54 water samples were collected at two oceanographic stations located in Admiralty Bay. Ranges of seasonal changes were found for the values of ten parameters: water temperature, salinity, dissolved О, pH, the contents of PO4 , Si, NO2, NO3, chlorophyll α and plant carotenoids at six depths between surface and 400 m. Data for temperature and salinity showed the absence of distinct thermoclines or haloelines which reflects the very low stability of waters in the Bay. The concentrations of nutrients were high during the entire year and they were not limiting for phytoplankton growth. Only nitrates decreased distinctly during algal blooms. The high dynamics of waters in the Bay causes a lowering in the chlorophyll α content to a maximum of about 2 mg/m3. Oceanographic, hydrochemical and hydrological conditions in Admiralty Bay are typical for the Antarctic shelf waters in this geographical region.

Classification of water masses in the area investigated during the 1981 FIBEX Expedition and two winter expeditions at the "H. Arctowski" Station using the method of Empirical Orthogonal Functions (EOF) is presented. Four basic water masses (warm and cold Bellinghausen Sea surface waters, surface Weddell Sea waters, Circumpolar Warm Deep Water (CWDW) and the transitional zone) were observed in the area and a significant dependence of water masses distribution ón depth was found. A strong winter increase in the Weddell Sea waters influence was recorded.

Density, composition and domination structure of the sea ice microalgae in the Admiralty Bay (South Shetland Islands) were investigated in 1983. Algae were recorded both in discoloured and in colourless sea ice from June to October. The highest algae density, amounting to 5 x 105 cells in 1 cm3 was observed till the end of August, the diatoms Nitzschia cylindrus and N. curta being the dominant species. A total of 95 algal taxa. mostly diatoms, were recorded. Air temperature seems to be an important factor influencing the development of algae in sea ice.

During the BIOMASS-SIBEX Antarctic expedition the distribution of Copepoda in three water layers (0—100, 100—300 and 300—500 m) in the Bransfield Strait and southern Drake Passage was studied. Altogether 46 taxa were recorded (Tabs. 1 and 2); the number of taxa increased with depth. Faunistic differences between the Drake Passage and the Bransfield Strait were observed. In some species the age-related splitting of the populations was registered (Figs. 2, 3 and 4). Young generations occupied usually the upper water layers.

The amount and composition of lipids m some Antarctic animals were studied. The material consisted of crustaceans (Euphausia superba, Paramoera sp., Orchomene sp.), tunicates (Salpa thompsoni) and vertebrates (Notothenia rossi marmorata and Hydrurga leptonyx). The author's data are discussed on the background of available literature information.

On the basis of comparable habit, leaf morphology and leaf cell pattern, leaf and stem sectional anatomy, Dichelyma antarcticum C. Muell. is reduced to synonymy with Blindia magellanica C. Muell.

At the turn of October 1985, the abundance of breeding Adelie penguins was estimated at the Hope Bay oasis on the Antarctic Peninsula and on Seymour Island. In the Hope Bay rookery, 123850 pairs of penguins were recorded, beginning their breeding at the end of October. Data so far obtained indicate a continuous increase in the number of birds sat this rookery. On the other hand, the Seymour Island colony consisted of 21954 pairs of Adélie penguins. Clear differences in the geomorphological structure of areas occupied by penguins in those two places are discussed. No gentoo penguins were detected in either of the colonies.