THE ABUNDANCE OF PICOPHYTOPLANKTON AND CORRELATION ANALYSIS WITH ENVIRONMENTAL FACTORS IN JIAOZHOU BAY
胶州湾微微型浮游植物丰度及其与环境因子的相关性分析

The abundance and distribution characteristics of picophytoplankton in the Jiaozhou Bay in four seasons were investigated by flow cytometry, and the correlations with environmental factors was analyzed. The abundance of Synechococcus ranged from 2.17×102 cells/ml to 2.329×104cells/ml. It was high in the western waters and the inlet of Jiaozhou Bay. The abundance of Synechococcus in the bottom layer was only significantly higher than that in the surface layer in summer. There was obvious difference between the Synechococcus abundance of summer and winter. The Synechococcus abundance of three continuous stations (B3, C4 and D5) fluctuated, and showed two peaks in 13:00 and 3:00 respectively. The abundance of Picoeukaryote ranged from 1.028×103 cells/ml to 8.651×104 cells/ml, and it was high in the western waters. There was no significant difference among all water layers in four seasons. The Picoeukaryote abundance of spring and summer were obviously higher than autumn and winter. The Picoeukaryote abundance of continuous stations also fluctuated as the Synechococcus. Principal components analysis showed Synechococcus and Picoeukaryote had complicated relationship with different environment factors in four seasons. In winter they were positively correlated with temperature. In other seasons, they were mainly influenced by nutrients.