Exploring the process of phytoplankton population changes in relationship to physical and chemical factors in Gomishan shrimp ponds, southeast of the Caspian Sea

This study was conducted to evaluate water quality impacts on phytoplankton community and nutritional status of the Gomishan shrimp ponds. During the breeding season (May-October 2016), water was sampled using one-liter dark bottles from 6 ponds and in each pond, three stations, near the entrance, the middle and near the outlet. At the sampling site, some physical and chemical factors of water were measured and recorded, including: temperature, salinity, pH, dissolved oxygen (DO), turbidity and EC. Water Samples were transferred to the laboratory for measuring nitrate and phosphate, as well as the identification and counting of phytoplankton. Total of 23 genus belonging to 6 phylum recorded for the ponds. Bacilloriophyta and Dinophyta phylums dominated the phytoplankton community in June. There was a significant difference in phytoplankton phylum abundance among months of study period (P<0.05). The results showed that all recorded environmental factors were in an optimal range, while DO and salinity variations were considerable. Pearsons test analysis revealed that there is significant correlation between phytoplankton abundant and environmental factors in the study period.