Study of Some Limonological properties of Sanandaj Azad Dam Based on Zooplankton Structure

This survey was carried out on the diversity and structure of zooplankton and fish during to summer 2015 to spring 2016 in the lake of Azad dam in Sanandaj, Iran. The sampling of fish was done by gill net and Electrofishing method was also used for sampling of the Cumasi River with a current of 1.7 amps and 100-300volts. Zooplankton sampling was carried out at 5 stations seasonally by 50 micron plankton net with a diameter of 36 cm. In the present study, 23 species of zooplankton were identified, 20 species belong to the holoplankton and 3 species belong to meroplankton groups. The results showed that the zooplankton population was 3276 ind./m3 in the autumn, which was lower than in other seasons. In winter, the density increased and peaked in the spring.  In all seasons, the rotifera accounted the highest density were of zooplankton was observed. The highest density at stations 5, 4, 2, 3 and 1, respectively. In this study 12 species of fish were identified, 11 species of the Cyprinidae and 1 species of the Nemacheilidae. The Alburnus sellal, Capoeta trutta and Carassius auratus were present in all seasons in dam and rivers. In summer, the density of the fish was 258 specimens, falling in the fall and reaching 47 specimens in the winter. From the spring, a high increasing (448 specimens) was observed in the catch, which 353 specimens belonged to the species Alburnus sellal that contained 79% of the fish caught in this season. Considering that the reservoir volume of the dam is 300 million cubic meters, there are on average about 39 tons of zoplankton in the reservoir, which is available aquatic animals of dam, especially larvae, fingerlings and fish. Considering the state of zooplankton in terms of the amount of food for fish and larvae, the dam can be used for fishery exploitation and proper management.