Comparative study on the community stucture of phytoplankton in winter in different oceanic function zones of Fujian seacoast

Based on a special campaign of oceanic research 908 ,the community structure of phytoplankton of Fujian seacoast was investigated during December,2006 to January,2007 in order to compare phytoplankton dis-tribution in different oceanic function zones. The result showed that 112 species belonging to 55 genus of phyto-plankton in the study waters were identified,including variety,form and cyst. Among species compositions,dia-toms contributed to 97 species of 48 genus,pyrrophyta contained 10 species of 5 genus,and others were lower. Diatom was dominant in phytoplankton community in terms of species and density. Pyrrophyta were mostly identi-fied in middle seacoast and Dongshan island in the south of seacoast zones. Cyanophyta were rarely observed while Chrysophyta ralatively increased compared with historical data. The average density of phytoplankton was 422.31×102 ind/dm3 with a higher distribution situation in the south and middle,lower in the east of seacoast zones. The horizontal distribution of chlorophyll a was generally the same,as the with phytoplankton density dis-tribution,but was different in seacoast zones and far-off ocean in the east,middle and in diminant species' horizon-tal distribution. Red-tide species were in a large number. Some seacoast zones in south and middle areas were dominant by some red tide species. Compared with historical data,dominant species of diatoms variaed obviously. Pyrrophyta increased was to grow in species number and density. The quantity of phytoplankton increased with little change in horizontal distribution.