Impact of Sturgeon pen culture on the water quality in Gorgan Gulf.

The percent study was carried out to determine the impact of Sturgeon pen culture activities on the water quality from August 2015 to July 2016 in Gorgan Gulf. The study was done at 3 pen culture sites in Ashoradeh Island, Bandar Tourkman. Sturgeons with averaged weight of 21.00 ±12.28 kg /pen and 25.00 ±21.66 Pieces /pen were taken from sea respectively. Total input feed were recorded during the experiment in this study. 5 sampling stations with 3 repetitions were selected which were in distance 0, 5, 25, 50 and 100 m from pen sites. Physico – chemical factors of water were evaluated. Results of season variations of Physico – chemical factors of water showed that, there were no significant differences between SD, Turbidity, Chol a and Cyano biomass, P and PO4-3 (p>0.05). However, there were significant differences between BOD5, COD, TDS, NO2-, TAN and TDS (p<0.05). At the sampling station far from the pen, TDS and Clα and biomass value was found to decrease and turbidity value was found to increase. The maximum amount of Chol a, BOD5, COD, NO2- and TAN were in the station which was 25 m far from the pen sites which showed a significant differences with the other stations (p<0.05). The results also proved that feeding can cause increase, though not significant in P and PO4-3 values around the pen. However, there was significant difference between stations. These results indicate that the pen culture had maximum effect on water quality in distance 5 m far from the pen sites.