South Yellow Sea - Northern East China Sea Suspension Characteristics, And Surface Sediment Organic Carbon Distribution

In this paper, based on a comprehensive survey of China's Coastal Sea Investigation and Research Project (908), 1122 surfical sediments and 112 suspended matter samples collected in the shelf of the South Yellow Sea and the northern East China Sea were utilized, and the POC, PN, TOC, TN,δ13C were measured. This paper analyzed the distribution rules of the particulate organic carbon and sedimentary organic carbon in the shelf of the South Yellow Sea and the northern East China Sea, the sources and controlling factors of the organic carbon were also discussed.The horizontal and vertical distribution of the POC showed that the concentration of the POC in the nearshore zone was higher than in the far-off bank area, and the concentration of the bottom POC was higher than the surface layer under the effects of water masses and the resuspension. For example, the concentration of POC in the adjcent area of the Changjiang Estuary was the highest, while it's lower in the middle mud area of the South Yellow Sea. The results of C/N ratios showed that marine autogentic plankton was the main supply of the suspended particulate organic carbon except that there were some terrestrial organic matters in the adjcent area of the Changjiang Estuary.Controlled by the style of the sediments, the content of the TOC and TN were high in the mud area, but low in the sandy sediments. However, when the grain size turned more and more fine, the content of the TOC was not higher. When the grain size was under 6φ, the content of the TOC increased with increasing fine grain, and remained stable when it's between 6φand 10φ, but with the grain size was over 10φthe content of the TOC was instead decreased. Theδ13C and C/N ratios showed that the surfical sedimental organic carbon in the South Yellow Sea and the northern East China Sea was minly from the ocean autogentic plankton. The terrestrial organic carbon was only in the estuary area such as the Old Huanghe River Estuary and the Yangtze Estuary. This conclusion indicated that the even though the sediments were from the terrene, the marine autogentic plankton could be the sources of the organic carbon of the sediments, which was consistent with the research result of the POC.