Phytoplankton Investigation and Environmental Assessment for Dredged Area in Caohai Section of Dianchi Lake, China

In this paper, phytoplankton investigation and environmental assessment for the dredged areas in Caohai section of Dianchi Lake in Kunming City were reported. After microscopic identification and counting of 7 water samples (one of them is control plot), the water environment was evaluated by the phytoplankton species and quantity which were assessed by the biological diversity index, including Maglarf, Shanon-Wiener, Simpson diversity index, Pielou index and Berger-Parker dominance index. The results showed that there were mainly 21 species of algae, and among them, Microcystis spp., Melosira spp., Oscillatoria spp.et al., were the dominant species. So the water was assessed as eutrophication, polluted water band B. Based on the diversity index analysis, the dredged area sampling sites were relatively higher than the un-dredged areas in biodiversity of phytoplankton. Summarily, the water quality after dredging had been improved. Phytoplankton biodiversity indicators should be the important water environmental assessment method.