(Table 1) Population density and biomass of the foraminifer Rupertina, and grain size of cores from the Norwegian continental slope

Rupertina stabilis occupies a depth restricted biotope of suspension feeding animals situated at the Norwegian continental margin. It extends from the Voring plateau northwards for at least 200 - 300 km, in depths between 600 and 800 m. This slope position is known for relatively strong bottom currents and shifting watermass boundaries. - The species is attached to hard substrates, mainly stones or hydroid stalks and obviously prefers an elevated position. It is building a permanent cyst of sponge spicules and debris at the apertural region. The spicules are used to support a pseudopodial network similar to that described from Halyphysema (LIPPS 1983). It is believed to serve as a filter apparatus. - A review of known occurences in the Atlantic is given, suggesting a temperature adaption of the species ranging from 0°C to a maximum of 8°C. Specimens were successfully cultured for about 2-3 weeks

Spatial and temporal distribution patterns of benthic foraminifera in the Northeast Water Polynya, Greenland

Abundance, biofacies and ATP content of benthic foraminifera (>63 μm) were studied in the Northeast Water (NEW) Polynya (77–81°N, 5–17°W) over the ice-free summer, 1993, to investigate how a polynya system might influence the underlying benthic community. In the living assemblage, distinguished by Rose Bengal staining, over 60 taxa could be identified. The biofacies identified was similar to that of other Arctic shelf habitats. Foraminifera were counted in 3 size fractions (63–125 μm, 125–250 μm and >250 μm), with 65% of the foraminifera occurring in the smallest size fraction (63–125 μm). Total abundances (>63 μm) in the uppermost 1 cm averaged approximately 200 ind/10 cm3 and declined down-core, as did the number of species. Abundances and species composition correlated positively with sediment chlorophyll and ATP content, with maxima occurring in the shallower northern regions of the polynya, suggesting a general dependence on food. Foraminera biomass was estimated to be 0.1-0.3 g Corg/m2. Abundances, biomass and ATP content were comparable to ice-free, deep-sea regions in the Norwegian Sea. Temporal changes observed over a 2 month period at one location were difficult to distinguish from spatial and analytical variability. Contrary to expectations, growth was unpronounced at the community and at a species level, implying either a delayed response of the benthic foraminiferal community to food inputs from the overlying water column or the presence of biological limitations other than food, such as predation

Palaeoenvironmental investigation of sapropelic sediments from the Marmara Sea: A biostratigraphic approach to palaeoceanographic history during the last glacial-Holocene

High-resolution micropalaeontological examination of two cores recovered from the Central Basin of the Marmara Sea distinguishes seven biostratigraphical zones within pre-sapropelic (Pr1 & 2 zones), sapropelic (Sap1 & 2 zones) and post-sapropelic (Po1-2-3 zones) sediments. The pre-sapropelic sediments at the basal section of the cores reflect the lake stage of the Marmara Sea when it was isolated both from the Black and Mediterranean seas. First colonization of foraminifers at about 11-10.4 ky BP indicate the beginning of marine conditions following the entry of Mediterranean waters through the Canakkale Strait. Sapropelic sediments deposited at about 10.3-6.2 ky BP were associated with enhanced productivity of the surface waters, as inferred from the confined abundance of Globigerina bulloides in sapropelic zones. The first stage of the sapropelic deposition started under anoxic-close to anoxic bottom water conditions and continued in dysoxic-suboxic conditions, as deduced from benthic foraminiferal assemblages. Towards the end of the sapropelic deposition, suboxic conditions dominated. The most enriched 8180 values occur within the sapropelic sediments suggesting that a relative freshening of the surface water must have occurred after deposition of the sapropelic sediments; this observation casts doubt on the postulated strong Black Sea outflow during their formation