Investigation on Harmful Algal bloom (Red tide) of Cochlodinium polykrikoides in the Persian Gulf of Iran

The monitoring of the harmful bloom of Cochlodinium polykrikoides in the northern Persian Gulf was studied during 2010 to 2011. The results revealed that in the waters of Hormozgan Province, the Diatoms and Dinoflgellates had the highest frequency. No significant difference was found for amount of nutrients in three sub- regions. The bloom of C. polykrikoides was higher in central sub-region in spring and was occurred in the eastern sub-region in summer, but no mortality of fishes was recorded. In Bushehr Province, four classes of Bacillaryophyceae, Cyanophyceae, Dynophyceae and Prymnesiophyceae were determined. Furthermore significant different values of nutrients were recorded. In waters of Khuzestan Province, different values of NH4 were measured for different months. In total, the measured ratio of N: P in all months were lower than Redfield Ratio (16:1) in which subsequently the environmental condition was not suitable for bloom of C. polykrikoides.