Remote sensing study of the seasonal distribution of phytoplankton groups in the South China Sea

Distribution of phytoplankton groups in the South China Sea (SCS) is retrieved from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) data using a classification method named PHYSAT. Four major phytoplankton groups including haptophytes, Prochlorococcus, Synechococcus-like cyanobacteria and diatoms are distinguished. It is found that the Prochlorococcus and Synechococcus-like cyanobacteria are the dominant species over the deep basin in the SCS, while the haptophytes and diatoms prevail along the coastal area, which is consistent with the previous reports. We also compare monthly distribution of phytoplankton groups. From November to February, Prochlorococcus is the dominant over the entire SCS. The haptophytes is the dominant species along the coast of China. The dominant species is diatoms along the southeast of Vietnam. From March to June, both Prochlorococcus and Synechococcus-like cyanobacteria cover the entire SCS and the area dominated by haptophytes decreases. Instead of haptophytes, the diatoms become the dominant phytoplankton group along the coast of China. Large patches of Synechococcus-like cyanobacteria cover continental slope of the northwestern SCS during July and August. Haptophytes and Prochlorococcus accumulate in the east of Vietnam in August. The Synechococcus-like cyanobacteria starts to extend towards the southern of SCS during September.