Pesticides will be released into aquatic systems after application in agriculture or industry. AOPPs （aryloxyphenoxypropanoic acids） herbicides, including fenoxaprop, quizalofop-P-ethyl and haloxyfop-methyl, can pose aquatic toxicity on cyanobacterium M. aeruginosa （Microcystis aeruginosa）. The inhibition percentages of the biomass of M. aeruginosa exposure to 10 mg＇L-I fenoxaprop, quizalofop-P-ethyl and haloxyfop-methyl on day 7 were 23.13%, 7.55%, and 7.56%, respectively. Protein content was also inhibited by the three AOPPs to fenoxaprop is the most toxic, followed by quizalofop-P-ethyl varying degrees. The growth and protein content results showed that and haloxyfop-methyl. It indicates that both the biomass and the protein content can be served as an indicator for evaluating the toxicity of the three chemicals. Growth rates of M. aeruginosa exposure to fenoxaprop are also the most significantly different compared to the control, which means that fenoxaprop is the most toxic among the three compounds. Results from this study may provide insights for evaluation of environmental risks of AOPPs. In addition, such insights will be helpful for guiding the application of AOPPs in agriculture.
