The role of Pseudomonas fluorescence bacteria in developing of algae culture

This project was conducted to determine the effect of Pseudomonas fluorescence bacteria on increasing the growth rates of some species of algae namely Chaetoceros Sp., Skeletonema sp., Tetraselmis sp., Chlorella sp. In this order, the mentioned bacteria were extracted by separator and Zobell 16E media from prawn broodstock ponds, then purified and mass cultured. The algae selected mass, were cultured in Conway media and then these bacteria were investigated at the blooming phase in the several experiments of various treatments in combined culture method. The results revealed that the mentioned bacteria could apply as a partial substitution body of aglae media and it could be used as a new media in various percentages. The results indicated, the very positive effect of bacteria on cultured algae. Therefore, Pseudomonas fluorescense can be used in algae cultured in 50-150 mg\lit density as a new method for algae culture. This bacterium Could be a new media for Chaetoceros sp., and Tetraselmis sp., but for Skeletonema sp., other percentages of media should be used

Study on physic-chemical parameters of waters for fish cage culture site selection in the southern of Caspian Sea

Marine aquacultures growth require good quality water is leading to high efficiency and low risk to human health. In other words, the water quality is a critical factor to success and failure of the aquaculture industry. The aim of this project is to study water quality and the trophic status at the different depths and layers in the southern Caspian Sea based on environmental parameters and nutrients during three periods (2008, 2009 and 2010-2011) in order the feasibility of fish cage. Results showed that water temperature, transparency, pH, dissolved oxygen were varied 5.50-32.60 ̊C, 3.50- 10.00 m, 7.15-8.80 and 3.18-12.00 mg/l at the different depths and layers, respectively. In addition, The values of NH4^+, NH3, NO^2-, NO3^- and PO4^-3 were 0.001-0.140 mg/l, 0.01-22.63 µg/l, 0.1-21.2 µg/l, 0.001-0.423 mg/l and 0.008-0.071 mg/l, respectively. Inorganic nitrogen (DIN/N), inorganic phosphorous (DIP/P) and total phosphorous (TP) were registerd 0.68-14.75, 0.07-0.68 and 0.01-2.67 µM, respectively. Thermal startification are more important for fish-breeding. Thermal stratification was occurred from depths greater than 20 m in late spring to early fall in the Caspian Sea. Optimum transparency for fish farming cage was considered less than 5 meter which in this study were recorded from 20 to 50 meter depths. The range of the standard of pH and dissolved oxygen for fish farming cage were 7.80-8.50 and >5 mg /l that in current study results of pH and dissolved oxygen were consistent.Various forms of nitrogen (ammonium, nitrite and nitrate ) at the different layers were acceptable and less than the threshold limit of Australia and New Zealand. But, phosphate value was more than threshold limit of Australia and New Zealand at some layers depth during years of 2009 and 2010- 2011. The results of the nutrients compared with data from the reference year (1996-1996 ) in the Caspian Sea was shown that this ecosystem passed oligotrophic status and shifted to mezotrophic and eutrophic condition. In addition, the values of NH4/N, NO3/N and DIP/P compared with eutrophic condition of reference year (2005) showed that Caspian ecosystem was not passed euotrophic condition and it still under mezotrophic status. As a conclusion, it seems that offshore of the Caspian Sea (depths between 20 to 50 meter) were suitable for different species of fish for cage culture. But, since 2000 decayds the Caspian Sea has experienced four times algal bloom (toxic and harmful species) and in recent years a number of other species also has reached to bloom potential and also mezotrophic condition of this ecosystem, it is appropriate that the establishment of fish farming cages carried out as a pilot to more precautionary approach which not lead to environmental disaster