Abstract: The biological pump is one of the important pathways for the net absorption of atmospheric CO2 and is also a key linkage between the upper ocean and benthic ecosystems in the polar oceans. This article summarizes the research on biological pumps carried out systematically in the Prydz Bay, Amundsen Sea, Cosmonaut Sea, Bering Sea, Chukchi Sea, Canada Basin, and other Arctic and Antarctic seas in the past 10 years by utilizing the unique functions of radionuclides and stable isotopes. These studies depicted the dynamic characteristics and spatial variation of processes such as biological uptake of carbon, export of particulate organic carbon, degradation of organic matter, regeneration of nutrients, and burial of sedimentary organic matter. In addition, the effects of environmental factors such as freshwater components, particle concentration, and trace Fe on the biological pump were also explored. Our study found that freshwater components, such as sea ice meltwater, glacier meltwater/river water, etc., affect the spatial variation of carbon fixation rate, Fe uptake rate, and POC export flux by changing water stratification, light availability, and nutrient supply; organic matter degradation and nitrification dominate the nutrient regeneration; and the formation of Antarctic bottom water and the cross-shelf transport of particulate matter affect the surface-bottom coupling of biological pumps. Facing the dual pressures of future climate change and human activities, it is urgent to strengthen research on the interaction between biological pumps and food webs to accurately grasp the laws and mechanisms of changes in polar marine ecosystems.

Key words:  marine biological pump, radionuclide, stable isotope, Southern Ocean, Arctic Ocean