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Number of results: 13
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Abstract

Seventy−six species of Polychaeta were found in 19 quantitative samples collected in the deep sublittoral (200–500 m) of Admiralty Bay (South Shetlands). Three assemblages were distinguished by similarity analysis (clustering, nMDS). The soft bottom in depths from 200 to 300m was strongly dominated by Maldane sarsi antarctica and had very low species richness and diversity. The second assemblage was distinguished in the areas of the sea floor in the same depth range but with aggregations of Ascidiacea and Bryozoa. It was again characterized by high abundance of Maldane sarsi antarctica , but showed significantly higher species richness and diversity. Diversity of polychaete feeding guilds was also high in these areas. This pattern was probably associated with an increased habitat complexity due to the presence of dense aggregations of large suspension feeders. High species richness and diversity was also noted in the third assemblage, associated with the deepest sublittoral (400–500 m) of Admiralty Bay. This is the area characterized by very stable environmental conditions, where the assemblage was dominated by Tharyx cincinnatus , Sternaspis sp., Maldane sarsi antarctica , and Asychis amphiglypta .
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Abstract

W ramach Programu B adań Stosowanych PBS został wykonany projekt „Innowacyjne metody i system do oceny zagrożenia tąpaniami na podstawie probabilistycznej analizy procesu pękania i geotomografii online”, w którym został opracowany, wykonany i przebadany prototyp systemu INGEO. Stanowi on kontynuację rozwoju systemów sejsmicznego ARAMIS M/E i sejsmoakustycznego ARES-5/E poprzez ich wzbogacenie o nowe, innowacyjne technologie i metody analiz. System został wyposażony w cyfrową transmisję na powierzchnię z wykorzystaniem światłowodów i lokalną w rejonie ściany z wykorzystaniem linii przewodowych. INGEO umożliwia ocenę zagrożenia tąpaniami metodami standardowymi: sejsmoakustyczną, sejsmologii, hazardu sejsmicznego, oraz opartymi na tomografii rejonu przed frontem ściany: pasywną z wykorzystaniem wstrząsów górniczych i aktywną z wykorzystaniem wzbudników lub organu urabiającego kombajnu. System wyposażono ponadto w otworowe czujniki zmian naprężenia i ultradźwiękowe czujniki deformacji wyrobisk w rejonie ściany z lokalną transmisją radiową do przesyłu danych do kanału cyfrowej transmisji przewodowej i światłowodowej. INGEO umożliwia współbieżną kontrolę deformacji w rejonie wyrobisk wokół ściany wydobywczej z precyzyjną kontrolą deformacji na powierzchni nad rejonem ściany w celu doskonalenia opracowanych stochastycznych modeli dla predykcji występowania zagrożeń spowodowanych wstrząsami górniczymi. Monitoring może obejmować szczególnie zagrożone rejony z wykorzystaniem geofonów i nowo opracowanych czujników lub obszar całej kopalni czy kilku połączonych kopalń z wykorzystaniem sejsmometrów. Ze względu na zastosowanie transmisji światłowodowej, precyzyjnie zsynchronizowanej zegarem GPS, strumieniowej transmisji danych oraz wielorejonowej detekcji zjawisk, INGEO stanowi zaawansowaną technicznie ofertę dla kopalń węgla kamiennego oraz rozległych kopalń rud miedzi.
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Abstract

Admiralty Bay (King George Island) is an Antarctic Specially Managed Area and one the most thoroughly studied small-scale marine basins in the Southern Ocean. Our study provides new data on the isopod fauna in this glacially affected fjord. Twelve species of isopods were recorded in this basin for the first time. Six of them were found for the first time in the region of the South Shetland Islands. The highest number of species new for Admiralty Bay were found in the families Munnopsidae (4 species) and Munnidae (3 species).
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Abstract

Fifteen species of isopods, representing 10 families, were recorded on holdfasts of the brown alga Himantothallus grandifolius . Material was collected in the 15–75 m depth range during the austral summer of 1979/80. The isopod community was dominated by Caecognathia antarctica (mean density 12.4 ± 13.1 ind./100 ml) followed by Cymodocella tubicauda (mean density 0.7 ± 2.1 ind./100 ml). Mean total density of isopods reached the value of 16.1 ± 14.0 ind./100 ml. The comparison with the other studies showed that hold− fasts are inhabited by a distinctive isopod community that differs from the isopod fauna associated with soft bottom of Admiralty Bay.
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Abstract

The study was aimed at analyzing patterns of abundance and diversity of macrozoobenthic communities along a depth gradient in the Admiralty Bay, a semi-enclosed basin located in a rapidly changing region of the western Antarctic Peninsula. The study concerns primarily the Polychaeta and Amphipoda, the taxonomic richness and diversity of both groups being analyzed at different taxonomic levels (species, genus and family). Such an analysis, which uses a basic surrogacy measure (low taxonomic resolution) can be very useful in future monitoring programs of the Admiralty Bay. The analysis was based on 35 samples collected in the summer seasons of 1984/85 and 1985/86, with a Tvärminne sampler (within the 7–30 m depth range) and an 0.1 m2 van Veen grab (deeper areas) along a transect with the depth changing from 7 to 502 m. The total macrozoobenthos abundance was found to decrease with depth, from 1581 ± 730 ind./0.1 m2 within the 7–30 m to as few as 384 ± 145 ind./0.1 m2 at 400–500 m. The number of phyla per sample was observed to increase along the depth gradient of 7–30 to 200–300 m but was substantially reduced in the deepest sublittoral (400–500 m). The results showed large differences between amphipods and polychaetes in their respective depth-related biodiversity changes. On the other hand, the diversity metrics used (Pielou’s evenness, Shannon-Wiener index, number of species per sample, number of genera per sample, number of families per sample) at different taxonomic levels within each group produced similar patterns, demonstrating the usefulness of surrogacy in studies of Antarctic fjords.
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Abstract

The distribution of pelagic Polychaeta in the Scotia Front region is presented. 6 polychaete taxa were recorded in the material with the most abundant Pelagobia longicirrata which constituted 86% of all collected specimens. The mixing of water masses in the frontal zone influence the quantitative distribution of polychaetes in the water column.
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Abstract

The method of construction and division of dendrites proposed by Florek et al. (1951) was used for defining of the Antarctic biojjeographic areas. The affinity matrices of Knox and Lowry (1977) resulting from the analysis of the distribution of Antarctic Polychaeta and Amphipoda were taken as a basis for dendrite construction The results of the present analysis are compared with the conclusions of these authors and similarities and differences are discussed on the background of the hitherto published biogeographic divisions of Antarctica.
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Abstract

By means of the synthetic diagram method (Romaniszyn 1970) populations of benthic Polychaeta at the depth ranging from 15 to 250 m of the Admiralty Bay (South Shetland Islands) were analysed. During the summer season of 1979/80 three replicate subsamples were taken at 18 stations situated along 3 crosssections using the Van Veen grab of a catching area of 0.09 m2 ; 61 benthic taxa of Polychaeta were recorded in these samples. The characteristics of particular assemblages are presented together with their tendency to change as a result of substrate quality, depth and position in the study area. Considerable affinity between the fauna of Polychaeta in the shallowest part of the bay and the composition and structure of polychaete assemblages occurring at Arthur Harbor (Anvers Island), which were described by Richardson and Hedgpeth (1977) was recorded.
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Abstract

Zooplankton in the water column from the surface to bottom was studied. Copepods were the dominating organisms. Average zooplankton biomass was about 5 g in 1000 m3 . The highest zooplankton density occurred between 300 and 600 m. The influence of the Scotia Front on the horizontal and vertical distribution of zooplankton is discussed.
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Abstract

Macrozooplankton was caught at 17 stations with a Bongo net from the 0-200 m layer. The stations were located near the pack ice edge, between Elephant Islands and the South Orkney Islands. The cluster analysis of 58 recognized taxa allowed to distinguish three regions: the western — near Elephant Island, the middle and the western one — at the South Orkney Islands. No clear difference in macrozooplankton species composition at the open sea stations and those near pack ice was found. The average biomass of macrozooplankton in the investigated area amounted to 82.8 g/1000 m3 (95% CL: 47.2-94.2 g/1000m3). Macrozooplankton was dominated by salps and krill. The biomass and 95% confidence limits were 52.0 g/1000 m3 (15.6-59.2 g/1000 m3) and 26.1 g/1000 m3 (8.4-30.4 g/1000 m3), respectively. Differences in the biomass distribution of some taxa in three distinguished regions were observed. Except of salps the biomass of particular taxa caught near the pack ice edge and the same taxa caught in stations distant from this edge were similar. The biomass of salps was evidently higher in most northern stations.
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Abstract

Herve Cove, a small, shallow and partly isolated basin, is strongly influenced by glacial freshwater inlfow, bringing significant amount of mineral suspension. Its mean annual content amounted up to 46 mg dm-3. Sea anemone (Edwardsia sp.), bivalves (Yoldia eightsi, Laternula elliptica and Mysella sp.), amphipods (mostly Cheirimedon femoratus) a well as some species of polychaetes constituted almost 95% of zoobenthos biomass and 90% of abundance. Four different assemblages of benthic invertebrates, with total biomass ranging from 0.002 kg m-2 up to 1.7 kg m-2, were distinguished in this relatively small (about 12 ha) area. It seems that the freshwater impact influences the composition of an assemblage occurring close to the edge of a glacier. Relatively rich crustacean fauna was encountered in the shallow part of the cove near its entrance. Almost complete lack of echinoderms in Herve Cove, that are common in the shallow Antarctic sublittoral, should also be noted. Macrozooplankton of Herve Cove was dominated by Copepoda. The most frequent and abundant species were: Oithona similis, Ctenocalanus citer and Metridia gerlachei. Far less numerous Chaetognatha represented by three species, Ostracoda, Polychaeta, Pteropoda and Siphonophora constituted only 2.5% of all planktonie animals collected.
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Abstract

226 taxa (180 identified to species) of benthic invertebrates are recorded from Admiralty Bay on the basis of the material collected by Polish Antarctic Expeditions. Main groups concerned are Folychaeta, Mollusca, Amphipoda and Echinodermata. For each species the bathymetric range, the frequency, the abundance and the geographical distribution are given.
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