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Recent, the new environmental problems of aquaculture are very strong links with the feeding mode which is intensive and high-density. For example, with the improvement of the scale and intensity of aquaculture, freshwater eutrophication problems have become more serious that many harmful algae, such as Microcystis aeruginosa, do harm to the fish with releasing of algal toxins, changing in dissolved oxygen and addling. And now, the drug prevention and cure is the main way to inhibit the growth of algae. However, it is blindness in using the drug of killing algae with lacking of study. Therefore, it is important to study of the medicines that benefit the safety of aquatic product and the effect on the water environment.This study was observed the negative effect of chemical medicines in the Microcystis aeruginosa, and the negative effect to green algae, fish, biological bait and water probiotics to select several medicines that can be controlling Microcystis aeruginosa in the low concentrations and environmental safety.This study has important medical applications value of inhibiting Microcystis explosive growing and keeping the security of water environment. And the results are as follows:1. Based on the test on killing Microcystis aeruginosa with55kinds of chemical medicines including fungicides and herbicides,10kinds of these at the20mg/L concentration levels own higher kill algae rate(≥60%)within7days. They are Benzoisothiazolinone(77.89%), Chlorothalonil(79.41%),Dimethomorph(67.18%),SodiumDichloroisocyanurate(76.39%),Pyri methanil(60.43%),propineb(71.47%),Man-cozeb(70.99%),Paraquat(94.23%),Terbutryn(87.50%),Mesosulfuron-methyl(89.42%).2.Analyzing the algal EC50value of the above10kinds of medicine and different concentration for Microcystis aeruginosa, Chlorella vulgaris, Scenedesmus of algicidal experiments. And analyzing the10kinds of drugs at different concentrations on the safe concentration for goldfish, half lethal concentration for Artemia and growth inhibitory effect for Bacillus subtilis at a certain conentration 3.Based on the effect of medicine on the security index, get4kinds of safety medicines which can kill effectively Microcystis aeruginosa. The algal EC50value of Microcystis aeruginosa within7days:1,2-benzisothiazoline-3-one(2.30±0.09mg/L); dimethomorph (5.23±0.26mg/L); iprovalicarb (4.20±0.35mg/L); paraquat (0.06±0.01mg/L).
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