Polish Polar Research

The distribution and some aspects of the ecology of Euphausia crystallorophias, Euphausia frigida, Euphausia triacantha and Thysanoessa macrura are presented. The investigations in the Polish Sector "A" show that E. triacantha is the northernmost and E. crystallorophias the southernmost species. These two species occurred least frequently. T. macrura was the most numerous and most regularly distributed species in the region under investigations.

Qualitative and quantitative composition of phytoplankton of the Olaf

Prydz Bay (Indian Ocean, East Antarctica) was determined on the basis of 49 samples collected at 34 sampling stations during the period from the 15th to 24th February 1969. Altogether 59 taxa of algae were identified — among them: 57 taxa of the class Bacillariophyceae, 1 species of the class Chrysophyceae and 1 genus of the class Dinophyceae. Species occurring most frequently and most abundantly in the Olaf Prydz Bay are diatoms: Thalassiothrix antarctica, Chaetoceros criophilus, Nitzschia curta, Rhizosolenia alata. At some stations Chaetoceros dichaeta occurred in great numbers. A decrease in phytoplankton numbers in the areas south of 67 S is associated with the lack of neritic algae among dominant species.

Studies were carried out in February 1969. Circulation of waters in Prydz Bay was of a cyclonic character. In the surface water layer higher water temperatures were recorded to the south and lower to the north. The predominant species of Copepoda were: Calanoides acutus, Calanus propinquus and Metridia gerlachei. The highest numbers of Copepoda were observed in the southern part of the Bay. The development of the tested populations of Copepoda is zonated, asynchronous, and occurs earlier in the south than in the north.

Between December 1978 and March 1979 studies on the ichthyofauna distribution in the regions of the Scotia Sea and Antarctic Peninsula were carried out on board of the r/v "Profesor Siedlecki" during the Fourth Polish Marine Antarctic Expedition. Fisheries were carried out using bottom and pelagic trawls. The presence of about 60 species of 15 families, including among others 17 species of Nototheniidae, 9 species of Chaenichthyidae and 7 species of Bathydraconidae was recorded. Iti the waters of the west regions of the Antarctic such species as Trematomus centronotus and Austrolycichtys botriocephalus were found.

Juvenile fishes of the family Nototheniidae were recorded during fishing for krill eastwards of the Balleny Islands. The paper describes juveniles of the most abundant species. Trematomus bernacchii and Pagothenia brachysoma, their distribution and abundance. Also the correctness of assigning of some juveniles to the species T. bernacchii is discussed.

During a cruise of the fishing vessel m/t "Sagitta" around the Antarctic, the occurrence of DSL was noted in a small area of the Pacific sector of the Antarctic waters. The layers were found at depths of 50—150 m. Their main component was E. carlsbergi (family Myctophidae), whose maximum density was within the range of 219—437 x 10 -4 fish/m3.

Analysis of food contents of 784 stomachs was made in 5 species of fishes of the family Nototheniidae: Notothenia coriiceps neglecta. Notothenia rossi marmorata, Notothenia nudifrons, Trematomus newnesi and Pleuragramma antarcticum. In the food of the first two of the mentioned species benthic forms predominated and among them Amphipoda were a decidedly preferred component. The composition of the food of N. nudifrons indicates that they feed at the bottom of the sea, the most preferred component of their diet, however, were pelagic Salpae. T. newnesi and P. antarcticum are characterized by a typically pelagic kind of food. The comparison of food composition and the values of the stomach fullness indices in N. coriiceps neglecta, N. rossi marmorata and T. newnesi in the summer and winter seasons shows a markedly higher feeding intensity in the summer.

Bacterial, enzymatic and chemical analyses pointed to active microbiological mineralization and transformation of penguin excrements at "maritime Antarctic". The following physiological groups of bacteria were found: proteolitic, amonifying, nitrifying, lecithin degrading, Са3(Р04 ) 2 dissolving, chitin degrading and spore forming ones. The number of molds was not significant. The nitrate reducers and N2 — fixing bacteria were not detected. About 50% of С and N were volatilized during three weeks. Some parts of N — NH3 was oxidized to N — NO3 in surface layer of the soil. The content of P increased during degradation of penguin excrements. About 1/3 part of total organic carbon content in bird excrements residues was derived from chitin.

Changes in chemical composition of the surface waters percolated through the soil and running off from the penguin rookeries are described. It was found, that the chemical composition of waters flowing from the breeding places depends on the size and rate of precipitation, and also on the location of rookeries. The longer and more complicated is the run off route of waters from the terrain of rookery, the more diluted are the solutions that reach the sea. In such case a significant part of phosphorus contained in the fecal materials may be retained on land, while most of ammonia volatilizates into the atmosphere.

Eggs and samples of the fat (blubber), muscles, and liver from three species of penguins: Pygoscelis adeliae, P. antarctica and P. papua were collected on King George Island in 1978. DDT residues were determined in the samples with the gas chromatography method. In the tissues pp'DDE and traces of pp'DDT were found, in the eggs merely pp'DDE. The highest DDT content (wet weight) was recorded in the fat of penguins, the lowest in the eggs. The differences between species in the mean values of the content of DDT residues in the tissues and eggs are not statistically significant. An increase in the level of pp'DDE concentration in the tissues and eggs of penguins was observed, as compared with earlier studies of other authors, as well as a tendency toward dippearance of the active form, i.e. pp'DDT, in the samples.

Using gas chromatography methods the content of DDT residues was determined in the tissues of 4 species of Antarctic birds: Oceanites oceanicus, Catharacta skua, Sterna vittata and Larus dominicanus, and in the eggs of Macronectes giganleus and Larus dominicanus. Samples were collected on King George Island, in February and October 1978. The highest level of DDT and its metabolites concentration was observed in the tissues of Oceanites oceanicus and the lowest in the tissues of Sterna vittata and in the eggs of M. giganteus and L. dominicanus. The differences in DDT content between different species and within one species are associated with their food composition and winter migrations to the regions with higher degree of DDT pollution.

The occurence of the crustacean Branchinecta gaini was observed in the fresh-water ponds on King George Island. Morphological structure of the following developmental stages was described: nauplius, metanauplius, adult males, adult females, and gravid females with egg-sacs filled with eggs. The active phase of the life cycle of this species lasts 6 months (November-May). During that time one generation of Branchinecta develops. The reproductive season lasts from January until the freezing of the ponds.