Study On Effect Of Microorganism-Photosynthetic Bacteria (PSB) On Ecological Environment Of Small And Middling Reservoirs

Six reservoirs in the Jilin Province for were chosen for this experiment, three of them was control groupe. In the experimental condition we isolated , enriched and cultured the photosynthetic bacteria(PSB). After reproducing the PSB with the water of well. We sprinked the PSB to the experimental reservoirs,then we conducted the experiment to investigate the hydrochemistry index, plankton biomass , the growth of silver fish and big head silver fish in the reservoirs. The results:1) PSB had obvious effect on hydrochemistry index of the reservoirs. SDn sulfide, nitrate-N and COD of the experimental group are lower than those of control group after sprinking PSB. The indexes decreased geatly in the experimental group but did not change very obviously in the control group. However, the COD in the experimental reservoirs did not reduced greatly and had no significant difference with that of control group . On the other hand ,DO, ALK, TH in the experimental reservoirs are higher than those of control group and changed obviously, but the same index of experimental group changed at different degree. This may be results of PSB in the different condition of reservoir. The results suggest that PSB can keep water quality well.2) PSB can effect the plankton biomass in the reservoirs.the phytoplankton of experimental group increased notably after application PSB. It also can make the algaes unfitable for fish decrease. On the other hand ,the zooplankton biomass is higher than that of the control group.3 ) PSB can effect the growth of silver fish and bighead silver fish.the weight gain in a day and surviving percentage of fish in the control group changed littlely. But the two indexes in the experimental group increased at some degree. The reason may be that PSB change the water quality well and increase the plankton which provided the fish good environment and enough food.To sum up, We conducted the effect of PSB on hydrochemical index, plankton , growth of silver fish and bighead silver fish in the reservoirs. This study has an important practical value for fish production.