Polish Polar Research

Influence exerted by various concentrations (0.01 to 50 ppm) of some chlorinated hydrocarbons (Aroclor 1254, Aroclor 1242, pp'DDE, pp'DDT and Lindane (ɣ НСН)) upon the photosynthetic assimilation of 14C02 in Antarctic marine diatom assemblage dominated by Corethron criophilum and some species of Nitzschia (Fragilariopsis group) has been investigated. The photosynthesis was fully inhibited by Lindane (ɣ HCH) in all applied concentrations To smaller extent the photosynthetic process was inhibited in turn by Aroclor 1242, pp'DDE and pp'DDT successively. Aroclor 1254 proved to be the least toxic. The possibility of the decrease of the primary production of the Antarctic diatoms caused by the chlorinated hydrocarbons was discussed.

Experiments have been carried out on the influence exerted by Aroclor 1254 upon the photosynthetic production of organic 14C by an assemblage of marine Antarctic diatoms (Thalassiosira sp. 48%, Nitzschia sp. 21%, Chaetoceros sp. 15% and Corethron iriophilum 10%). Samples of various numbers of cells per cm3 of water have been used. Incorporation of 14C02 by the diatoms proved to be proportional to the increased number of cells in the sample only at the lowest levels of concentration in per cm3. Further increase of the level of 14C in diatoms has not been found as number of cells in the sample kept growing. Calculation of brutto photosynthesis has indicated that low concentration of Aroclor 1254 (0,01 to 1 ppm) may stimulate the photosynthetic incorporation of carbon, yet the photosynthetic release of carbon from cells within the photorespiratory process is stimulated to a higher degree. High concentration of Aroclor (1 to 50 ppm) inhibit the brutto assimilation, yet the release of carbon during the photorespiratory process is inhibited to a higher degree. A hypothesis is being considered implying that the relation between the intensity of photosynthesis and intensity of photorespiration may vary according to the rate of concentration of Aroclor.

Antarctic krill carbohydrate content was followed during 1983—84 Eighth Polish Antarctic Expedition. The Admiralty Bay (King George Island) was th area of study. The following average values of three estimated fractions were obtained: 3.77 +- 1.51%, 0.47 +- 0.34% and 3.30 +- 1.33% for total, TCA-soluble and TCA-insoluble carbohydrates, respectively. Percentage contribution of the estimated fractions to dry weight varied seasonally (1.48—7.41%, 0.15—1.83%, and 1.28—6.28%, respectively). The carbohydrate content showed a clearcut cycle of changes over the calender year, with a minimum in autumn-winter and a maximum in spring-summer.

ll was proved that the activity of basic proteinases (pH 8.3) and acid proteinases (pH 4.0) of the Antarctic krill increases exponentially in spring-summer season (September-December); the activity of the first ones is 6 times higher and increases more rapidly. The positive relation between the proteolytic activity and the degree of gut filling of krill was also evidenced. The lack of high activity of acid proteinases in early spring does not support the suggestions of Ikeda and Dixon (1982) that during Antarctic winter krill takes energy from the autoproteolysis of own body proteins.

The period of nesting development of Wilson's storm petrels (approx. 60 days) could be divided into three stages: first from hatching to 8th—10th day of development; second, from 10th to approx. 25th day and third from 25th day until nestlings leave the nests. During the first stage hemoglobin concentration in the blood decreases significantly while total surface of erythrocytes and the hematocrit increases. At that time nestlings do not grow very fast. In the second stage of development the values of all studied parameters do not change, while the growth of body weight is very intensive. The last stage is characterized by significantly reduced growth rate accompanied by important changes of all hematological parameters responsible for the respiratory function of blood volume unit.

In colonies situated at the southern coast of King George Island the nesting areas of penguins of the genus Pygoscelis were investigated with respect to the protection of eggs and chicks against flooding. Relationships between the nesting strategy determined by the characteristics of breeding grounds, degree of colonization and breeding time, and the climatic conditions of zones in which majorities of particular species populations breed were presented. It was recorded, that interspecific differences in nesting strategy of pygoscelid penguins enable species which breed sympatrically to avoid competition for the nest-sites, and also seem to be responsible for various population dynamics of species in the maritime Antarctic.

This paper reports on eleven species of hepatics collected on King George Island, South Shetland Islands (6Г50'—62°15'S latitude and 57°30'—59 00'W longitude). A short account of the vegetation of this Antarctic island is provided and the role of liverworts in particular plant communities is discussed. Two species, Hygrolembidium ventrosum (Mitt.) Grolle and Scapania abcordata (Berggr.) S. Arnell are reported for the first time from the Antarctic botanical zone; the latter is recorded for the first time in the Southern Hemisphere and, additionally, this is the first record of the genus Scapania from Antarctica. A detailed description of the habitat of each taxon is given and distribution maps for the eleven species are provided. A key to the eleven species from King George Island is given, and a detailed taxonomic discussion is included for Cephaloziella varians (Gott.) Steph and Lophozia excisa (Dicks.) Dumort. The former is considered to be synonymous with the widespread Arctic species C. arctica Bryhn & Douin ex K. Müll.

A short review of the history of the hepaticological exploration of Antarctica is given in the present paper. An annotated check list of all taxa of hepatics reported from within the Antarctic botanical zone, based on literature data and unpublished records, is included. Altogether 22 species of liverworts, excluding two taxa known only at generic level, representing 18 genera and 13 families, are known to occur in the Antarctic. All species of hepatics, except for Cephaloziella varians which is also known from Greater Antarctica, occur exclusively in the maritime Antarctic region. In the livewort flora of Antarctica, the southern temperate and subantarctic elements are predominant (72.7%) and the bipolar element is remarkably scarce, albeit the bipolar taxa belong to the most widespread and frequent of the impoverished Antarctic hepatic flora. Distribution patterns of all known Antarctic liverworts are briefly discussed and several floristic elements and subelements are recognized.

Benthic gastropods (45 taxa) inhabiting 11 coastal areas of South-West Svalbard are listed. The dominant species are indicated; frequency of occurrence of various gastropods in different areas is discussed.

During marine ecological surveys conducted by Polish expeditions in South Spitsbergen area 14 fish species were collected. The length frequency, the diet and some other ecological informations are presented for the most common species.