STUDIES ON THE SPECIES COMPOSITION、BIOMASS AND SPECIES DIVERSITY OF PHYTOPLANKTON IN SALINE-ALKALINE PONDS WITH CHLORIDE TYPED

From 5 April 1997 to 1 September 1998,the species composition and biomass of phytoplankton were studied in saline-alkaline ponds in Zhaodian Fish Farm,Gaoqing County,Shandong Province. 387 phytoplankton samples were collected. Salinity ranged from 1.36-20g/L. Total alkalinity changed from 2.40-7.2 mmol/L,and pHranged from 8-9. The results indicated that the phytoplankton in saline-alkaline ponds had been composed of salt-tolerance species or halophile species,which occurs commonly in freshwater,some of them are halobiont species. The average biomasses of phytoplankton were 49.90?1.92mg/L.Diatom,Euglinophyta and Chrysophyta were dominant. The biomass of phytoplankton in control ponds without fish was fewer than that of fish-culture ponds. The features of species composition and biomass were discussed.