Abstract: Data about fish diversity in the Zhujiang River estuary from 2016 to 2018 were collected for the water environment data analysis and species diversity assessment. The results of RDA analysis showed that water depth, dissolved oxygen, water coverage, salinity, pH and water temperature had certain influences on fish, among which the degree of chromium influence on fish diversity accounted for 25.92% of the variables of overall water quality. During the experimental period, the parameters of seawater quality changed over time, and the response of family, genus, and species of fish to nitrite and lead changes was the most senstitive, especially the Cyprinidae. The large amount of industrial pollution discharged affected the fish population size. In addition, chromium and petroleum substances were the significant conditions that determined the fish diversity in the Zhujiang River estuary and largely limited the activity value of ecological space.

Key words: water quality, ecological assessment, fish diversity, ecological space, Zhujiang River estuary