Ecological characteristics of phytoplankton community from eutrophic waters in the Maluan Bay

present study is based on the analysis of the data collected in 10 dnas during the periods of 2 surveys (from May 1992 to January 1993 and from August 1993 to May 1994). The results show that the number ofphytoplankton in highly eutrophic waters of the Maluan Bay is low, Only 6-35 spotes from each cruise and 66species in total fain the 2 surveys. The phytoplanha abundanCe is high. The mean cell densities of phytoplanktonfrom the net samples were 21 386x 104 cells/m3 for the first sUrVey and 110 136 x 104 cells/m3 for the second survey,that fm the water Samples was 1 150. 7 cells/cm3. The mean concentration of chlorOPhyll a reachs 6. 67 mg/m3.Both the species diversity (H') and evennes (J) were low, only 0. 78 and 0. 28, restwhvdy. The temporal and spatial fluctuation of the cell denSity of phytoplankton was quite wificant, caused banly by contribution of pennate diatom Nitzschia delicatissima that often abudanily occurred in a ofed waters rich in organic matter and could be takenas an ecologic indicator of highly eutrophic harbour. The axistence of good correlation between the cell density ofNitzschia delicatissima and some environmental variables (e. g. Po43 - P and COD, etc. ), and the heterotrophic tendancy of this species are discussed, too.