Benthic foraminifera as palaeo sea-ice indicators in the subarctic realm - examples from the Labrador Sea-Baffin Bay region

摘要

Benthic foraminifera are found in a wide range of environments and may at times be one of few proxies available for the study of palaeoenvironmental conditions. However, the response of benthic foraminifera to changing sea-ice conditions is not well understood. This paper discusses benthic foraminifera as potential sea-ice proxies, with special emphasis on their use in shelf regions of the sub-arctic realm. Four marine sediment records from the Labrador Sea-Baffin Bay region serve as examples; in all four records independent sea-ice proxy will be used for testing the foraminiferal response to changing sea ice conditions. This test suggests that 1) Benthic foraminifera provide information on variations in sea-ice cover, but they are not direct proxies for sea-ice cover and no true sea-ice species has yet been identified. 2)Foraminifera mainly respond to the surplus of food often available at sea-ice edges. 3) Dominance of agglutinated foraminifera may suggest corrosive bottom-water conditions which may at times be linked to seasonal sea-ice cover.