Modern distribution of benthic foraminifera from Disko Bugt, West Greenland

Abstract

Benthic foraminifera were investigated from 20 grab samples collected from a large marine embayment, Disko Bugt, along the west Greenland margin. Agglutinated and calcareous foraminifera were found throughout Disko Bugt, with agglutinated species dominating 19 out of the 20 samples. The most common species are Adercotryma glomerata, Spiroplectammina biformis, Textularia earlandi, Cribrostomoides crassimargo and Reophax fusiformis. Six faunal assemblage zones were identified from cluster analysis and detrended correspondence analysis. The relationship between the foraminifera and environmental variables was investigated using canonical correspondence analysis. From this analysis, bottom water salinity and water depth were identified as the most important environmental variables explaining the foraminiferal assemblages. This result suggests water mass characteristics in Disko Bugt are an important control on the benthic foraminiferal assemblage zones. Where the warm and saline West Greenland Current water mass impinges on the seafloor, the assemblage is dominated by A. glomerata, T. earlandi, R. fusiformis and Reophax pilulifer. Sites with the cold, lower salinity Polar Water mass at the seafloor are dominated by S. biformis and A. glomerata, with common Cuneata arctica and C. crassimargo. In shallow locations with a relatively warm and low salinity surface water mass and coarse sediments the fauna is dominated by Cibicides lobatulus. In similar hydrographic locations with fine-grained sediments a mixed faunal assemblage dominated by Ammoscalaria pseudospiralis and Eggerella advena is found.