Abstract: An investigation was made on the succession of phytoplankton community and the main physical and chemical factors of water body in exalted shrimp ponds in Beiliao and Anli villages of Donghai Island, Zhanjiang during culture process, with the influence of the succession on the culture process analyzed. A total of 140 species of phytoplankton belonging to 76 genera and 7 phyla were identified. The dominant species in the two ponds with normal shrimp growth in Beiliao village were Gyrodinium spirale, Platymonas elliptica, Thalassiosira sp. 2, Gomphosphaeria lacustris  var. compacta, Gymnodinium sp. 1,Oocystis sp., Microcystis sp., Scrippsiella  trochoidea, Chroococcus sp., and Chroomonas acuta, while those in the two ponds with shrimp disease occurrence in the process of culture in Anli village were Microcystis aeruginosa, Gyrosigma tenuissimum, Amphora coffeaeformis, Phormidium tenue, Anabaena circinlis, Synechocydtis aquetilis, Chlamydomonas sp. 2, hroomonas acuta, and Gyrodinium spirale. The phytoplankton species, including dominant ones, were more abundant and complex in normal ponds than in disease-affected ponds. In normal ponds, the dominant species succeeded rapidly and alternated in phyla, while in disease-affected ponds, only Bacillariophyta species were replaced by Cyanophyta species during the succession. The phytoplankton cell density increased during the culture process in normal ponds, but decreased after a temporary increase at early culture stage in disease-affected ponds. No significant relationships were observed between the phytoplankton cell density and the main physical and chemical factors in the ponds during culture process. The diversity and evenness of phytoplankton species were higher in the normal ponds in Beiliao than in the disease-affected ponds in Anli, while the dominance degree of species was in reverse. The mild variability of water body’s physical and chemical factors as well as the high diversity and evenness but low dominance degree of phytoplankton species played important roles in keeping aquatic environment steady and healthy during the culture process in exalted shrimp pond.

Key words: Landscape pattern, Desert oasis, Fukang, Land utilization