Prydz Bay, Antarctica is a key region for global ocean circulation and biogeochemical cycling. The dense shelf water formed in the Prydz Bay in winter contributes 13%–30% of Antarctic Bottom Water, which plays a significant role in long‑term carbon sequestration in deep ocean. However, little is known about carbon cycling processes in the Prydz Bay during autumn–winter due to the lack of observations. Based on seawater samples collected during the 42nd Chinese National Antarctic Research Expedition (CHINARE) in March–April 2026, we investigated the pathways and timescales of carbon transport and transformation in the Prydz Bay with the help of Δ¹⁴C and δ¹³C of dissolved inorganic carbon (DIC).

Preliminary Δ¹⁴C results from two polynya stations and one continental slope station reveal that: (1) Vertical distributions of Δ¹⁴C (5–700 m) at the two polynya stations are relatively uniform, indicating strong air–sea exchange and vertical ventilation in the polynya; (2) DIC-14 ages at the western MacKenzie Polynya (closer to the ice shelf) are approximately 100 years older than those at the eastern Davis Polynya (influenced by the inflowing Circumpolar Deep Water), likely due to the incorporation of older ¹⁴C‑depleted meltwater from the ice shelf; (3) Δ¹⁴C values at the slope station (5–1100 m) range from –150‰ to –120‰, which are generally consistent with previous observations in adjacent areas, and show a clear increasing trend with depth.

These preliminary findings demonstrate the potential of DIC‑14 as a powerful tracer for identifying transport pathways of carbon in the Prydz Bay, providing key isotopic constraints for quantifying carbon sequestration fluxes in this region. Future work will integrate DIC concentrations, Δ¹⁴C, and δ¹³C data from additional stations to further elucidate the complete carbon cycle picture of the Prydz Bay.