Structure characteristics of phytoplankton community at Sanya Bay

The composition,abundance,community structure and diversity of the phytoplankton at the Sanya Bay were investigated in each season in 2004,and the relationships between these characteristics and environmental factors such as nutrients were discussed.A total of 169 species belonging to 67 genera of phytoplankton were identified.The cell abundance of phytoplankton varied from 6.48×104 to 165×104 cells·m-3,with an average of 87.59×104 cells·m-3.Diatoms had a predominant abundance all through the year,and dinoflagellates followed.The species diversity of phytoplankton at the Sanya Bay was very high.The annual variations of the phytoplankton abundance at the Sanya Bay showed an obvious two-peak cycle,with two peaks of cell abundance in spring and autumn and the lowest abundance in summer,and the abundance decreased towards the outer sea.