Environmental
DNA
Reveals Major Shifts in Fish and Amphibian Diversity and Distribution in Alpine Lentic Ecosystems of Southwest China, Supporting Improved Conservation and Management
Yuanfei Wang, Haoqi Yu, Sining Huang, Liuyang He, Xiuqin Lin, Yiheng Lin, Jianping Jiang, Jianghong Ran, Tian Zhao, Feng Xie ABSTRACT
Aim
Alpine lentic ecosystems are naturally fish‐poor or fish‐free, yet they have received numerous non‐native fish introductions globally. Studies have demonstrated that alien fish have negative impacts on aquatic organisms, particularly amphibians, which are highly susceptible to habitat alterations. In the Qinghai‐Tibet Plateau, widespread fish introductions from lowland areas have occurred in alpine lentic ecosystems. However, their associations with native amphibians remain unclear.
Location
The mountains of southwest China, a global biodiversity hotspot.
Methods
We used environmental DNA techniques to investigate shifts in fish and amphibian diversity and distribution, examined the associations of fish introductions with amphibian richness and occurrence using generalised linear models, quantified species co‐occurrence with probabilistic analysis, evaluated the relationship between fish richness and community composition using non‐metric multidimensional scaling, and assessed community similarity and assembly mechanisms with the Raup‐Crick index and modified stochasticity ratio. We further tested predation interaction between translocated fish and native amphibian species based on the observed negative co‐occurrence.
Results
In alpine ecosystems, introduced fish species outnumber natives tenfold (20 vs. 2). Intra‐regionally translocated fish (17 species, 77.3%) exhibited higher species richness and occurrence frequency than alien species (3 species, 13.6%). Introduced fishes were dominated by Cyprinidae (18 species, 81.8%), all occurring in lentic systems. Amphibian richness and occurrence were negatively correlated with fish richness. Introduced fish increased amphibian community similarity and shifted community assembly toward stochastic dominance. Translocated
Conclusions
Fish introductions have altered fish diversity and distribution in alpine lentic ecosystems, exerting negative effects on specific native amphibian species and communities, primarily driven by intra‐regional fish translocations. Our study provides key insights for managing introduced fish and protecting threatened and endemic amphibians in alpine lentic ecosystems of southwest China and similar highland regions worldwide.