Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 8
items per page: 25 50 75
Sort by:

Abstract

This paper includes a check-list of Recent Svalbard marine ostracods based on published sources and on diploma theses as well as some new studies. This is the first study of this group of crustaceans from Hornsund. A total of 41 species belonging to 12 families were collected at 55 sampling stations from dredged sediments. Seven species are reported for the first time from the Svalbard Archipelago. Polycope orbicularis Sars is the most abundant species in the present fauna. Species compositions of Hornsund and the Liefdefjorden are seen to have the highest similarity (S = 50.6).
Go to article

Abstract

During the 2004 summer season, 14 sediment samples were collected in Kongsfjorden and Isfjorden, West Spitsbergen, from 6 down to 345 m water-depth (mwd). The samples yielded abundant assemblage of monothalamous foraminifera, belonging to almost 40 morphotypes. Our qualitative (>125 um) and quantitative data (125-500 um) allowed to distinguish three water-depth related assemblages in both Kongsfjorden and Adventfjorden (branch of Isfjorden), indicating that soft-walled monothalamous foraminifera show similar habitat gradation along fjord axis as calcareous and robust agglutinated taxa. Among the monothalamous foraminifera, the subtidal assemblage (6 mwd) was dominated by various unidentified allogromiids. The second, shallow-water assemblage (44-110 mwd) was dominated by Psammophaga sp. 1-3, Hippocrepinella crassa, Hippocrepinella cf. hirudinea, and large Gloiogullmia sp. 2. The deep-water (150-345 mwd) monothalamous assemblage was dominated by Psammophaga sp. 4, pear-shaped Hippocrepina sp., Hippocrepina indivisa, and long Cylindrogullmia sp. 2, as well as large agglutinated species Hyperammina subnodosa with attached Tholosina bulla, Hyperammina fragilis and Lagenammina sp.
Go to article

Abstract

Bowseria arctowskii gen. et sp. nov., a new organic-walled monothalamous (single-chamber) foraminiferan is described from samples collected in Admiralty Bay (King George Island, West Antarctica) at 100- 200 m water-depth (mwd). The species is characterized by a large (1- 2 mm) elongate theca with a single terminal aperture. Molecular phylogenetic analyses, based on partial small subunit rDNA sequences, indicate that the new species belong to a clade of single-chambered foraminifers that branch as a sister group to the multi-chambered textulariids and rotaliids. The most closely related to the new species is an undetermined allogromiid from under the Ross Ice Shelf.
Go to article

Abstract

During the austral summer of 2002/2003 the author collected 38 marine and/or glacio-marine sediment samples from Admiralty Bay on King George Island (South Shetland Islands, West Antarctica). Recent “living” (Rose Bengal stained) and “dead” (subfossil) benthic foraminifera represented by 105 species belonging to 65 genera are recognized in samples from water depths of up to 520 m. They show large spatial variability. Four distinctive foraminiferal zones within the fjord of Admiralty Bay were recognized and analyzed in terms of environmental conditions. The zones are: restricted coves, open inlets, intermediate-, and deep-waters. The major environmental factors, which dictate foraminiferal distribution, are closely related to bathymetry and distance to open sea. Sediment composition and chlorophyll content appear to have minor influence on foraminiferal communities. Most diverse, deep-water faunas dominate water-depths below 200 m , which seems to be the lowest limit of atmospheric and meltwater influence. In waters shallower than 200 m , environmental features, affecting distribution of various benthic foraminiferal assemblages, appear to be sedimentation rate and hydrographic isolation. The results of this study gives promise to use the Admiralty Bay foraminiferal distribution pattern as a paleoenvironmental tool for shallow- to intermediate-water Quaternary marine research in fjord settings of the South Shetland Islands.
Go to article

Abstract

During the late 2007 austral summer, 20 sediment samples were collected in Admiralty Bay (King George Island, South Shetlands, West Antarctica) from 8 down to 254 m water-depth (mwd). The samples yielded abundant assemblage of monothalamous benthic foraminifera, belonging to at least 40 morphospecies. They constituted the first such collection from Antarctic Peninsula fjords and provided a new insight into this group’s diversity and distribution. Among organic-walled taxa, Psammophaga sp., Allogromia cf. crystallifera, and three morphotypes of Gloiogullmia were especially abundant. Agglutinated forms were dominated by Hippocrepinella hirudinea, Psammosphaera spp., Lagenammina spp., and various mudballs. Although, the majority of the morphotypes were known from other high-latitude locations, some were reported for the first time. Our quantitative data (>125 µm) showed the greatest differences between monothalamous foraminifera assemblages at shallowest water depths above 50 mwd. The deepest assemblages from between 179 and 254 mwd, were most similar, suggesting uniform near-bottom conditions at ~200 mwd throughout the Admiralty Bay.
Go to article

Abstract

Ostracods from Admiralty Bay on King George Island (South Shetland Islands) represent 29 podocopid species, belonging to 19 genera, one cladocopid and six myodocopid species. They were recovered from Recent marine and/or glacio-marine sediment samples from water depths of up to 520 m. These ostracods constitute a variable assemblage, which is overall typical for the Antarctic environment. Shallow-water assemblages tend to be more variable in terms of frequencies and species richness than deep-water assemblages. The later are low in numbers and remain relatively high diversities. Overall, no linear relation between ostracod assemblage-composition and environmental features analyzed was recognized.
Go to article

Abstract

Recent foraminifera represented by 24 species belonging to 20 genera are recognized in marine and/or glacio-marine sediment samples collected at water depths of up to 75 m in Goulden Cove (Admiralty Bay) on King George Island, West Antarctica. The foraminifer assemblages are dominated by benthic taxa, such as Globocassidulina biora and Miliammina arenacea, the two most abundant species in the studied biocenosis.
Go to article

This page uses 'cookies'. Learn more