Preliminary Studies on Phytoplankton and Red Tide Organism Composition in the Coastal Water of the Weizhou Island, Guangxi

According to the red tide investigation data ranging from March to November in 2006, the specific composition of phytoplankton and monthly change of dominant species of the coastal water of the Weizhou Island were analyzed. The phytoplankton were composed of 103 species belonging to 45 genera, including cyanobacteria of 1 genus ( 1 species ), diatom of 34 genera ( 83 species ), dinoflagellates of 8 genera ( 16 species ), chrysophytes of 1 genus ( 1 species ) and chlorophyta of 1 genus ( 1 species ). Analysis of the investigation data also showed that red tide organisms in the seawater of the Weizhou Island consisted of 60 species belonging to 29 genera, including cyanobacteria of 1 genus ( 2 species ), diatom of 18 genera ( 40 species ), dinoflagellates of 8 genera ( 16 species ) , chrysophytes of 1 genus ( 1 species ) and protist of 1 genus ( 1 species ). Dominant species were Phaeocystis globosa, Trichodesmium erythraeum, Thalassionema nitzschioides, Chaetoceros curvisetus and Chaetoceros lorenzianus, which all belonged to red tide organisms. Obvious subrogation of phytoplankton dominant species were observed, which correlated with the environment factors such as water temperature.