Recent benthic foraminifera in the Arctic Ocean and Kara Sea continental margin

Abstract

Living (stained) and dead (unstained) benthic foraminifera from the Arctic Ocean and Kara Sea continental margin have been investigated to extend the knowledge on modern living and dead benthic foraminifera in the Arctic Ocean. Three living and three dead benthic foraminiferal fauna assemblages have been distinguished based on Q-mode cluster analysis. In the seasonally ice-free Nansen Basin, a living assemblage consisting of Ioanella tumidula–Stetsonia horvarthi assemblage has been established. On the permanently ice covered Lomonosov Ridge and Alpha Ridge in addition to the seasonally ice-free Nansen Basin, the living assemblage is characterized by I. tumidula–Oridorsalis tener–S. horvarthi assemblage. The seasonally ice-free and relatively shallow Kara Sea continental margin displays a living fauna assemblage with agglutinated Reophax species in addition to the calcareous species Cassidulina neoteretis, Epistominella nipponica, and Islandiella helenae. The dead assemblages from Alpha Ridge, Lomonosov Ridge and Nansen Basin with assemblages characterized by I. tumidula, O. tener and S. horvathi reflect the living assemblages well. The dead fauna assemblage from the Kara Sea continental margin differs from the corresponding living assemblage by showing less agglutinated specimens and dominance by C. neoteretis. However, there is also a relatively good potential reconstructing paleoenvironmental change from the Kara Sea continental margin, when it is taken into account that the agglutinated species are not well preserved in the dead assemblages.