Differences in stream fish assemblages subjected to different levels of anthropogenic pressure in the Taizi River catchment, China

This study was conducted in the Taizi River catchment, located in northeastern China. Six representative streams in three regions (upper mountains, middle hills, lower plains) with different levels of anthropogenic disturbances were surveyed to describe the structure of fish assemblages and their relationship to environmental parameters. The results showed that the fish assemblages were significantly different among the three regions in the Taizi River catchment. Indicator species analysis found ten representative fish species in the Taizi River catchment and four species in the upper, four species in the middle, and two species in the lower regions. The ecological traits of the representative fish species were generally in agreement with the physiochemical features of the streams located within different regions. Multivariate analysis indicated that altitude, water temperature, and total nitrogen were the three most significant environmental parameters influencing the fish assemblage structure in the Taizi River catchment. Based on the different environmental features and fish assemblages found in each region, fish management and conservation strategies should be tailored to the specific characteristics of each region.