Inorganic Carbon of Sediments in the Yangtze River Estuary andJiaozhou Bay

摘要

JGOFS results showed that the ocean is a major sink for the increasing atmospheric carbon dioxide resulting from human activity. However, the role of the coastal seas in the global carbon cycling is poorly understood. In the present work, the inorganic carbon (IC) in the Yangtze River Estuary and Jiaozhou Bay are studied as examples of offshore sediments. Sequential extraction was used to divide inorganic carbon in the sediments into five forms, NaCl form, NH sub(3) H sub(2)O form, NaOH form, NH sub(2)OH HCl form and HCl form. Studied of their content and influencing factors were also showed that NaCl form < NH sub(3) H sub(2)O formNH sub(2)OH HCl form>NH sub(3) H sub(2)O form>NaCl form>HCl form, and that the contribution of HCl form contributes little to carbon cycling, HCl form may be one of end-result of atmospheric CO sub(2). So Yangtze River estuary sediment may absorb at least about 40.96 x 10 super(11) g atmospheric CO sub(2) every year, which indicated that offshore sediment play an important role in absorbing atmospheric CO sub(2).