Recent Arctic shelf foraminifera; seasonally ice covered vs. perennially ice covered areas

Abstract

Benthic foraminifera are abundant, highly diverse, and predominantly calcareous on siliceous sponge reefs of the western Axel Heiberg shelf. A total of 110 species, including 38 agglutinated taxa, were identified in 47 surface samples taken during the Ice Island Project. Living specimens usually constitute less than 3%, indicating a residual fauna. An important environmental parameter is the perennial ice cover, which causes high salinity, a low sedimentation rate, and a limited food supply. The availability of niches with sufficient nutrient supply and the diverse nature of the seafloor control a small scale, patchy distribution of benthic foraminifera. The foraminiferal assemblage of Lancaster Sound and off the coast of Baffin Bay differs from the Axel Heiberg assemblage by being less diverse, dominated by agglutinated species, and showing an increased living component. The seasonal ice cover, increased input of meltwater, lower salinity, and higher sedimentation rate are prime controlling factors in the distribution of benthic foraminifera in the sound.