Abstract:Based on the analysis of dissolved organic carbon (DOC), particulate organic carbon (POC) and chlorophyll a (Chl-a) of the water samples collected from eighteen stations in Sanggou Bay in August, 2012, according to the different aquaculture characteristics, the horizontal distribution of DOC and POC, and the source of POC were discussed. The results showed that the concentrations of DOC ranged from 1.70 mg/L to 2.82 mg/L, with an average of 2.03mg/L. The DOC demonstrated a decreasing trend from the west to the east. The concentration of POC ranged from 0.04 mg/L to 1.33mg/L, with the average of 0.55mg/L. The POC demonstrated an increasing trend from the south to the north. The concentrations of DOC and POC in net-cage culture area showed the highest values, followed by the coastal waters of Sanggou Bay. The DOC and POC concentrations were the lowest in the kelp culture area, indicating a direct relationship between the concentration of organic carbon and aquaculture species. Preliminary analysis of the source of POC based the POC/Chl-a ratios, showed that the living phytoplankton were the main source of POC in the bivalve, kelp, and bivalve-seaweed aquaculture areas, the coastal water and the offshore control area, while degraded organic matter was found in the net-cage culture area.
