【Title】Decomposition of Organic Carbon and Inorganic Carbon beneath Euphotic Zone in Prydz Bay, Antarctica
【Abstract】As the most important carbon pool in the ocean, particulate organic carbon (POC) plays an important role in marine carbon cycling. During the 25th Chinese National Antarctic Research Expedition (CHINARE-25), the decomposition ratio of organic carbon and inorganic carbon of Prydz Bay was calculated with a simple mathematical model. In the mean time, the re-mineralization efficiency of POC during sedimentation over the continental shelf of Prydz Bay was estimated according to the ratio of OC/N in the surface sediment. The results showed that the POC concentration of Prydz Bay ranged from 24.38 to 446.40μg?dm-3, with an average of 118.16μg?dm-3. Based on the observed data (dissolved inorganic carbon, dissolved O2 and nutrients), calculated remineralization ratios of elements were 164.1, 135.2 and 19.29 for O/P, C/P and N/P, respectively. At the P2 section on the continental shelf of Prydz Bay, the ratio of the decompositions of the organic carbon and inorganic carbon during their burial processes was 1.27 (mole ratio), and 81% of the POC in upper water was remineralized and re-involved in the marine carbon cycling, when it was buried to the seabed.