Abstract: The Chukchi and Bering Seas are connected by the Bering Strait. To investigate the impact of climate change in this region, excess ²¹⁰Pb was measured to compare sedimentary processes between the two seas. Results for the Bering Sea station demonstrated an effect from benthic fauna, whereas biological activity at the Chukchi Sea station was limited. The sediment accumulation rate was 0.6 ± 0.1 mm/a and 2.1 ± 0.07 mm/a in the Chukchi Sea and Bering Sea, respectively. The particle mixing coefficient related to benthic fauna at the Bering Sea station was 1.38 ± 0.92 cm²·a^-1 without considering sediment processes and 0.65 ± 0.95 cm²/a considering sediment processes. Burial fluxes of organic carbon, biogenic opal, and CaCO3 in the Bering Sea were 6.85 mmol C·m^-2·d^-1, 37.7 mmol Si·m^-2·d^-1, and 3.15 mmol C·m^-2·d^-1, respectively, and in the Chukchi Sea were 5.71 mmol C·m^-2·d^-1, 9.78 mmol Si·m^-2·d^-1, and 3.08 mmol C·m^-2·d^-1, respectively. Vertical transport by a high efficiency marine biological pump characterized the Chukchi Sea station, whereas lateral transport was predominant at the Bering Sea shelf station. Therefore, ²¹⁰Pb in marine sediments could be applied not only to quantify sediment accumulation rates and burial fluxes of biogenic materials but also to indicate the intensity of biological activity in benthic environments.

Key words: biogenic materials, burial flux, sediment accumulation rate, particle mixing coefficient, ²¹⁰Pb