Vertical Flux Of Settling Particulate Matter In The Yellow Sea And The East China Sea

Particulate matter is the main carrier for carbon vertical transportation in the sea,it plays important role in Earth's Carbon Cycle. The Yellow Sea and the East China Sea are typical continental margin seas (CMS) with abundant biodiversity. For these seas, particulate matter acts significantly in the process of benthic-pelagic coupling, not only provides essential food resource for benthic communities. Particle flux research in these seas is meaningful for the study of ecosystem dynamics of CMS.SPM was collected using Bloesch multi-tube sediment traps surface tethered at ten stations in the outer of Haizhou bay (station El), the Cold Water Mass in the Yellow Sea (station 1-3, 1-5, 1-7, 1-8, E2), the boundary of the Yellow Sea and the East China Sea (station E3), the Changjiang Estuary (station E4), the Zhejiang coastal upwelling (station E5) and the middle continental shelf area in the East China Sea (station E6), which represent the whole sea area, in summer (2002, 8) and autumn (2002, 9).Microscopical examination showed that inorganic fine particulates and particulate aggregates were the main types of SPM. Larvacean houses, fecal aggregates, diatom aggregates and miscellaneous aggregates were the major types of aggregates. Another type of aggregates mainly composed of dictyocha skeleton was also found occasionally. Aggregates in the bottom layer were much smaller than those in the upper and middle layer because of the turbulence in the bottom of the water column. As measured, the contents of organic carbon, organic nitrogen, total carbon, total nitrogen, and total phosphorous of SPM decreased with depth of the water column, whereas the flux of SPM and its component increased with depth. Increasing of inorganic particulates caused by resuspension maybe the main reason for the two different tendencies.Thermocline was the main area of autogenic particles in the water column of the Yellow Sea in summer. The costal current and the warm current of the Yellow Seawere both considered increasing the component contents of SPM in the upper layer of the thermocline at stations 1-3 and 1-8. The flux of POC at the other three stations was about twice that at station 1-3. The contribution of lateral current to the resuspension flux was also estimated. Intensive influence of lateral current at station 1 -5 maybe related to the complex environment around its location between two cold centers in the Cold Water MassPOC of SPM at El station originated mainly from sediment reuspension and plankton. Intensive resuspension resulted in the abundance of suspended particulate at station E3. The degree and depth influenced by resuspension at station E3 was much higher than that at El station. Thermocline resulted in the seasonal difference of flux of SPM and POC in the middle of the Yellow Sea. The contribution of particulate matter driven by lateral current to the total resuspension flux in summer was much greater than that in autumn. POC was stored more easily in sediment in station E2 and E3 than in station E1.C/N ratio of SPM in the Changjiang Estuary was greatly influenced by terrestrial matter. The higher biomass of plankton made great contribution to the flux of SPM and POC in the bottom layer in the middle continental shelf area in the East China Sea in autumn. The ability of vertical transportation was higher in the Zhejiang coastal upwelling than that in the middle continental shelf area in the East China Sea. It was obvious that the influence of lateral current to the bottom layer in the Zhejiang coastal upwelling was stronger than that in the middle continental shelf area.Influenced by sediment resuspension in the continental Margin Sea, resuspended particulate generally was the main component in SPM. In this paper, the resuspension ratios in the bottom layer at 6 stations were calculated by using two different resuspension models. Two results were basically consistent, suggesting that the vertical flux of SPM in the lower layer of the thermocline could represent the net vertical flux of SPM in the water column...