Abstract:

The Changjiang River provides the main source of sediment and terrestrial derived organic carbon to the Changjiang large delta-front estuary in the East China Sea. This study took sediment cores in December 2009 and November, 2010 in order to study the OC cycling under the influence of natural and anthropogenic disturbance.  The study showed that episodic flooding event, East Asian monsoon, excess nutrient input and dam construction, affected the sedimentary OC cycling in the ECS.  Based on the two investigations, the big flooding event in July, 2010 affected the redistribution of the surface sedimentary terrestrially derived OC in the ECS.  The benthic-pelagic decoupling of Chl-a is likely due to the lateral transport of marine derived organic carbon before their deposition. Sedimentary decay and preservation of OC showed spatial and temporal variability between near-shore stations and offshore stations, and between sediment mixed layer and accumulation layer.