Relationship between recent Planktic Foraminifera and water mass properties in the Western Ross Sea (Antarctica)

Abstract

Planktic foraminifera collected in floating traps were studied in two stations of the Western Ross Sea. The assemblage is composed of one species (Neogloboguadrina pachyderma) of which two morphs were distinguished: the first with thin and lobate test constitutes the juvenile stage and is present in the uppermost levels of the water column. The other morph has heavily encrusted test and is represented by a small number of specimens occurring at depth greater than that of the chlorophyll maximum. The depth of the chlorophyll maximum seems to be responsible for the foraminiferal abundance peak, thus confirming the hypothesis that this species is linked to the chlorophyll maximum. We found no relationship between foraminifera distribution and the physical parameters of the water column emerged, or with the biogenic fluxes. Intrusions of modified Circumpolar Deep Water are shown by the presence of dextral coiling specimens.