Distributions of the Arctic sea ice biomarker proxy IP25 and two phytoplanktonic biomarkers in surface sediments from West Svalbard

Abstract

The concentrations of the sea ice biomarker proxy IP25 (Ice Proxy with 25 carbon atoms) and two phytoplankton biomarkers (a tri-unsaturated highly branched isoprenoid (HBI) lipid (HBI III) and epi-brassicasterol) have been measured in surface sediments from West Svalbard. IP25 concentration exhibited a positive relationship with that of HBI III and epi-brassicasterol, suggesting that the rapidly fluctuating sea ice dynamics characteristic of West Svalbard have a similar impact on these sea ice and phytoplankton lipids, as hypothesised in earlier studies. Alternatively, the multi-year sedimentary signal may simply represent an integration of more subtle variations in biomarker distributions that reflect variability in sea ice conditions on a seasonal or annual timeframe. Our findings contrast with those reported previously for the Barents Sea, possibly due to the latter experiencing a more prominent and consistent sea ice advance/retreat cycle.