Dynamics of dissolved and particulate organic matter in the Changjiang (Yangtze River) Estuary and the adjacent East China Sea shelf

Abstract

Abstract Two cruises that passed over Changjiang freshwater, through the Changjiang Estuary, and finally to the adjacent East China Sea (ECS) shelf were carried out in July 2015 and March 2016. The concentrations of dissolved organic carbon (DOC) and particulate organic carbon (POC) were measured at the three layers (surface, middle, and bottom) of 99 and 89 stations during the cruises in July 2015 and in March 2016, respectively. The concentrations of DOC and POC showed overall decreasing trends from land to sea; however, their highest concentrations always occurred around the mouth of the Changjiang River, where estuarine salinity fronts and turbidity maxima appeared simultaneously. The POC/DOC ratios showed values