Distribution characteristics and influencing factors of particulate organic carbon in the Yellow Sea and the Bohai Sea in summer of 2016

Abstract

Based on the date of cruises that carried out in the Yellow Sea and the Bohai Sea during the summer of 2016. The concentration and special distribution of particulate organic carbon (POC) were analyzed and combined with the distribution of salinity, chlorophyll and POC/PON, POC/Chl a the source of POC were analyzed. Results showed that the average concentration of POC in the Bohai Sea, the North Yellow Sea and the South Yellow Sea were (500.2±226.5)μg/L, (358.2±101.5)μg/L, (321.0±158.1)μg/L,respectively. The concentration of POC in the Bohai Sea was higher than that in the Yellow Sea. The highest POC concentration was in the coastal zones and it tended to decrease toward the far shore on the whole. POC/PON was 8.89,POC/Chl a was 182.52 in the surface layer, POC/PON was 8.87, POC/Chl a was 179.56 in the middle layer, POC/PON was 9.41, POC/Chl a was 178.80 in the bottom layer. The high value of POC/PON and POC/Chl a had a certain relationship with the rotten of Enteromorpha prolifera. The result of correlation analysis showed salinity, total suspended matter and Chl a had a significant relationship with POC in the Bohai Sea which were the main factors influencing the distribution of POC in the Bohai Sea. In addition to the surface POC in the South Yellow Sea, there is no significant correlation between POC and salinity, total suspended matter, chlorophyll in other layers. POC in the Bohai Sea was mainly influenced by terrestrial and phytoplankton. POC in the Yellow Sea was influenced by various factors such as Changjiang Diluted Water, Yellow Sea warm current, Subei coastal current, biological and sediments. Organic debris were the main source of POC in coastal of Jiangsu and Qingdao near shore.