Correlations between Environmental Factors and the Distribution of Juvenile Hucho bleekeri in the Taibai River, Shaanxi, China

Abstract

Sichuan taimen (Hucho bleekeri) is a national highly protected wild animal that faces significant impacts from habitat degradation and loss. To study the habitat selection by H. bleekeri, data on the Taibai River and the distribution of juvenile H. bleekeri were recorded seasonally between February 2017 and January 2018, and habitat selection was assessed using the suitability curve method. The results indicate that the average distribution density of juvenile H. bleekeri in the Taibai River is 0.08 ± 0.09 ind./m, with an optimal elevation range from 1200 to 1600 m, river sinuosity range from 1.0 to 1.2, and vegetation coverage between 0.7 and 1.0. When choosing a microhabitat, juvenile H. bleekeri individuals tend to inhabit water areas with a water depth of 0.65 ± 0.33 m, flow velocity of 0.50 ± 0.24 m/s, and offshore distance of 7.66 ± 4.25 m. Furthermore, smaller juvenile fish prefer nearshore habitats with lower flow velocities and shallower water depths. The results provide technical support for the protection and restoration of the habitat of H. bleekeri.