| Summary: | We test the bulk parameters (TOC and δ13Corg) and lipid biomarker concentrations along a 2400 km surface sediment transect in the Bering-Chukchi Sea. TOC values were between 0.4 and 1.8%, with a generally decreasing trend from the Bering Sea shelf to the Chukchi Plateau, except for a higher value at the northernmost station. δ13Corg values were in the range of -23.2 to -22.2‰, with small variations except for the low value (-25.7‰) at the northernmost station. IP25 concentrations (0–109 ng/g) increased northward from the Bering Sea shelf, reaching their highest values at the summer ice edge on the Chukchi Sea shelf, then decreased towards the Chukchi Plateau. In contrast, phytoplankton biomarker concentrations of HBI III (0–368 ng/g), brassicasterol (0–854 ng/g) and dinosterol (14–404 ng/g) generally decreased northwards, with highest values on the Bering Sea shelf and elevated values in the vicinity of the summer ice edge. Concentrations of the terrestrial plant biomarkers ∑(C27+C29+C31) n-alkanes (219–2695 ng/g) and ∑(C28+C30+C32) n-alkanols (342-2818 ng/g) were highest north of the Bering Strait.
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