Abstract: To clarify fish community structure and diversity in Lake Gaobaoshaobo and the effects of environmental factors on fish community, we conducted fish resource surveys in four consecutive seasons (April, June, September, and December 2022) in three lake regions of Lake Gaobaoshaobo: Lake Gaoyou, Lake Baoying, and Lake Shaobo. A total of 48 fish species (which belonged to 12 families and 36 orders) were collected, among which Cypriniformes accounted for 70.8% of the total species captured. There were nine dominant species, including Coilia ectenes taihuensis, Carassius auratus, Aristichthys nobilis, Culter dabryi, and Hypophthalmichthys molitrix. How-ever, there were differences in the composition and dominance of dominant species among the lake areas. The predominant species in Lake Gaoyou and Lake Shaobo was Coilia ectenes taihuensis, and was Aristichthys nobilis in Lake Baoying. From the perspective of fish diversity, the Margalef species richness, Shannon index, and Pielou index of the fish community of Lake Gaobaoshaobo were 1.80-2.20, 1.36-1.68, and 0.61-0.74, respectively. The quantitative analysis results of Random Forests showed that the degree of water pollution and zooplankton biomass were the main factors leading to the differences in the fish diversity indices of Lake Gaobaoshaobo. In comparison with historical data, the number of fish species in Lake Gaobaoshaobo has declined and the composition of fish resources has changed, but the trend of fish miniaturization has slightly eased. The implementation of fishery management, water quality, and bio-food resources were the potential major factors for the changes of fishery resources in Lake Gaobaoshaobo.

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