Study On Ecotoxicity Of Butachlor And Beta-cypermethrin On Two Species Of Marine Microalgae

This paper studied single toxicities and joint toxicities of beta-cypermethrin and butachlor on Platymonas subcordiformis and Dunaliella salina(marine economy microalgae).The results showed that, the 24h-EC₅₀ 48h-EC₅₀ 72h-EC₅₀ and 96h-EC₅₀ of butachlor to Dunaliella salina were 0.0117mg/L 0.0187mg/L 0.0236mg/L and 0.0241mg/L, the 24h-EC₅₀ 48h-EC₅₀ 72h-EC₅₀ and 96h-EC₅₀ of butachlor to Platymonas subcordiformis were 1.436mg/L 2.735mg/L 3.271mg/L and 3.323mg/L,the 24h-EC₅₀ 48h-EC₅₀ 72h-EC₅₀ and 96h-EC₅₀ of beta-cypermethrin to Dunaliella salina were 7.74mg/L 8.45mg/L 10.35mg/L and 13.47mg/L, the 24h-EC₅₀ 48h-EC₅₀ 72h-EC₅₀ and 96h-EC₅₀ of beta-cypermethrin to Platymonas subcordiformis were 1.78mg/L 2.53mg/L 2.9mg/L and 3.93mg/L. In the chronic toxicity test, cell density concentration of photosynthesis pigments and protein of Platymonas subcordiformis and Dunaliella salina were influenced differently. The results of the joint toxicity test showed that, beta-cypermethrin and butachlor were synergistic of their toxicity in 24h, but antagonistic in 48h 72h and 96h respectively.The results indicated ,the growth of Platymonas subcordiformis and Dunaliella salina were restrained in the exposed concentration of beta-cypermethrin and butachlor. The inhibition degree was related to the concentration of the pesticides,the inhibition degree was higher when the concentration of pesticides was higher. The toxicities of the two kind of pesticides to the same kind of algae were significantly different, the tenderness of the two kind of algaes to the same kind of pesticide were different too. Rank the toxicities of butachlor and beta-cypermethrin according to the toxicity classification of pesticide: Butachlor was high toxic to Dunaliella salina,but was low toxic to Platymonas subcordiformis; Beta-cypermethrin was low toxic to Platymonas subcordiformis and Dunaliella salina.This study not only offers basic data for toxicity assessment, risk appraisement of pesticide and the further study of toxicity mechanisms of pesticide, but also it was important in biotest on the water environment pesticide pollutant ,offer basic data for protection of halobios fountain, ocean entironment and stabilization assessment of...