In this study, we used HPLC based measurement of the relative abundance of different phytoplankton groups associated with microscopic observations to confirm the calculated results, especially the dominated group and species. Seawater samples for phytoplankton pigment analysis (4-10 L, based on biomass) were filtered through 47 mm GF/F glass fiber filters (under a vacuum pressure less than 75 mm Hg and in dim light).