Estimation of production potential in lake behind the Halilrud dam in Jiroft city

In order to the physical and chemical factors, planktons identification, determination of Chlorophylla and primary production in lake on study wad conducted, behind the Halilrud dam in Jiroft city. For this purpose 5 station selected and sampling was performed seasonally. Compersion of physical, chemical factors and planktons were done by duncan multiple test range. Studied factors had the suitable value for fish culture. In classes of Chrysophyceae, Bacillariophyceae and, Chlorophyceae had the most frequency respectively. Totally 49 phytoplanktons genus were identified which 18, 14,8,5 and 3 genus were related to Chlorophy ceae, Bacillariophyceae, Cyanophyceae, Dinophyceae and Chrysophyceae, genus respectively. Nitzchia and Navicula in Bacillariophyceae, Chlorococcum, Pediastrum, Staurastrum and Tetradron in Chlorophyceae, Spirulina, Chroococcus, Phormidium in Cyanophyceae and Dinobryon in Chrysophyceae had the most frequency. From Various group of zooplankton, Copepoda, Naplius, Cladocera, Rotifera (Brachinus, Keretella), Trichuridae were identified in winter season and Rotifera was the most of all. Chlorophylla had not significant difference in 9 seasons but it had significan difference in 5 depthes. Increasing in depth causes to decrease chlirophyla. The most chlorophylla was in 0.5m depth (4.7 mg/m3 ) and the least chlorophyllla was in 20m depth(0.82mg/m^3) primary production in lake was calculated by chlorophylla equal to 154 kg/ha/year