Algae Biomass and Nutrient Condition in Fish Ponds in Coastal Polders

The relationship between Algae biomass and nutrient condition of the water body was studied in the fishpond ecosystem in coastal polders in Jiangsu Province. The results showed that there were 7 phyla and 127 species of algae in the fishponds. During 7 months of a year (from April to October), the average population and biomass of algae were 119.39×10 ⁶ entries/L and 90.6 mg/L, respectively, which varied dynamically. Cyanophyta, Chlorophyta and Bacillariophyta were the dominant phyla of algae in the ecosystem. The major water environment factors influencing the composition of populations were N/P ratio and total P. The results of this experiment showed an extremely significant negative correlation between algae biomass and N/P ratio.