| Summary: | 碩士 === 國立中山大學 === 海洋科學系研究所 === 102 === Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Estimates of primary production, however, indicate that previous POC fluxes of the ECS might be overestimated as a result of sediment resuspension. In the shelf waters of the ECS, concentrations of total suspended matter (TSM) generally increase with depth, strongly suggesting sediment resuspension. In the Kaoping Canyon, sediment resuspension has also been reported. To better understand the effect of sediment resuspension on trap-collected sinking particles in the ECS and Kaoping Canyon, in this thesis a vertical two end-member mixing model is used to evaluate the POC fluxes according to data of POC, rare earth elements (REEs; Pr, Yb), and elements Zr and Y in both suspended and sinking particles. The results demonstrate that the ratios of resuspended particles from sediments to trap-collected sinking particles in the inner, middle and outer shelves of the ECS were 92%, 86% and 56% by the POC approach, 56%, 16% and 34% by the REEs approach, and 60%, 13% and 47% by the Zr-Y approach, respectively. These results suggest that strong sediment resuspension (> 50%) occurs on the inner shelf of the ECS. The vertical mixing model is not applicable to the estimation of POC fluxes in the Kaoping Canyon because of strong lateral transport. In conclusion, the vertical mixing model used in this thesis ignores Changjinag plume (or terrestrial) inputs and lateral transport, while it includes biological degradation of sinking particles, and makes significant progress in both correcting the resuspension problem and evaluating reasonable, quantitative estimates of POC fluxes in a marginal sea. Overall, this model is still not a perfect model to estimate sediment resuspension fluxes accurately, because of ignoring riverine input and lateral transport, but it needs a better model to accurately estimate POC flux in next future.
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