Calcareous foraminifers and hydrographic parameters in 113 bottom samples from the southern Kara Sea were examined to improve the usage of foraminifers as paleoenvironmental proxies for river-dominated high-latitude continental shelves. Foraminiferal taxa form a succession from near-estuarine to distal open-sea locations, characterized by a gradual increase in salinities. Foraminiferal assemblages are discriminated into three groups: riverproximal,-intermediate, and-distal. This succession appears to be controlled by a combination of feeding conditions and bottom salinities, and are related to riverine fluxes of freshwater, organic matter, and sediments. Morphological and behavioral adaptations of foraminifers to specific environments are discussed.

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[1] We measured the oxygen isotopic composition of planktonic and benthic foraminifera in three cores collected at key positions to reconstruct the paleoceanography of the Barents Sea: core ASV 880 on the path of the northern branch of Atlantic water inflowing from the Arctic Ocean, core ASV 1200 in the central basin near the polar front, and core ASV 1157 in the main area of brine formation. Modern seawater d 18 O measurements show that far from the coast, d 18 O variations are linearly linked to the salinity changes associated with sea ice melting. The foraminifer d 18 O records are dated by 14 C measurements performed on mollusk shells, and they provide a detailed reconstruction of the paleoceanographic evolution of the Barents Sea during the Holocene. Four main steps were recognized: the terminal phase of the deglaciation with melting of the main glaciers, which were located on the surrounding continent and islands, the short thermal optimum from 7.8 ka B.P. to 6.8 ka B.P., a cold mid-Holocene phase with a large reduction of the inflow of Atlantic water, and the inception of the modern hydrological pattern by 4.7 ka B.P. Brine water formation was active during the whole Holocene. The paleoclimatic evolution of the Barents Sea was driven by both high-latitude summer insolation and the intensity of the Atlantic water inflow.