Abstract:Phytoplankton community structure were studied based on the data of netz phytoplankton by a 32 station grid survey, which was carried out in the spawning ground of the East China Sea and its adjacent waters from 4th to 18th May 2000. Three phyla including 33 genera and 90 species (not including unidentified taxa) were found in the survey area. The major phytoplankton group was Bacillariophyta, but the Dinophyta and Cyanophyta are also significant at some stations. The dominant species were Skeletonema costatum, Coscinodiscus jonesianus, Coscinodiscus radiatus, Ceratium tripos, Trichodesmium thiebautii, Noctiluca scientillans and Ditylum brightwellii. The horizontal patterns of phytoplankton cell abundance were mainly dominated by diatoms and dinoflagellates. Abundance of diatom and total phytoplankton was high in the northwestern part of the surveyed area, and abundance of dinoflagellates was high in the central and northern part of the surveyed area. The species richness was high in the eastern and southern spawning ground, and the Shannon Wiener index and the evenness of phytoplankton were relatively high in the central and eastern spawning ground.
