Distribution Pattern of Fish Richness in the Yarlung Zangbo River Basin

Global warming significantly affects plateau glaciers and surface runoff, and fish are bound to be severely affected. Additionally, an increasing number of human activities (e.g., free captive animals, aquaculture) have led to vulnerable plateau ecosystems being affected by invasive species. To address the above issues, we collected the currently published fish distribution data, and for the first time constructed a richness and fluvial system distribution map of the Yarlung Zangbo River fish (4 orders, 10 families, and 61 species). Based on fish richness and the fluvial system, the native fish in the Yarlung Zangbo River Basin were divided into three clusters, and the non-native fish were divided into six clusters by using Ward's minimum variance clustering and non-metric multidimensional scaling (NMDS). Environmental factors related to native or non-native fish richness were selected by the random forest model from 21 environmental factors. Then, the relationship between fish richness and environmental factors was explained by the generalized linear model (GLM). Our results showed that the native fish distribution pattern was different from the non-native fish distribution, but their high richness areas were overlapped. Furthermore, native fish richness responds differently than non-native fish richness to environmental factors. The results provided eco-solutions for the conservation and management of fish biodiversity and natural resources in the Yarlung Zangbo River.