Seasonal dynamics of benthic Foraminifera in a glacially fed fjord of Svalbard, European Arctic

Seasonal variations in benthic foraminiferal populations from a sediment-la den fjord were analyzed in order to provide insights into arctic foraminife ral ecology and to improve the interpretation of the late-glacial record, T he fjord is 25 km long and 100 m deep with a large tidewater glacier at the fjord head. A pilot transect of eight stations sampled in August 1995 reve aled the typical off-glacier sequence of foraminiferal taxa, Unidentified a llogromiids were abundant in the vicinity of the Ice front. Further down th e fjord Elphidium excavatum f, clavatum and Cassidulina reniforme co-domina ted the glacier-proximal fauna. Nonionellina labradorica and Islandiella no rcrossi characterized the glacier-distal setting. In 1996 three glacier-pro ximal stations were then sampled in March, May, July, August, September and November. Compared to the summer of 1995 the summer of 1996 was colder, re sulting in weaker glacial meltwater discharge, acid the foraminiferal fauna became less influenced by glaciers. This is portrayed by an increase in gl acier-distal N, labradorica and a decrease in glacier-proximal C, reniforme and especially E. excavatum. Taxonomic diversity was higher in winter, pos sibly reflecting a more stable environment in the absence of the turbid mel twater plume, the source of ecological stress.