Identifying Potential Protected Area for Native Fish in Arid Regions Under Compound Climatic and Hydrological Change

Freshwater fishes remain inadequately considered in the planning of river protected areas (RPAs), a concern in eco‐fragile areas such as arid regions. However, range shifts of fishes driven by climate‐related hydrological change, which affect spatial prioritization of habitats, have not been sufficiently considered, challenging the effectiveness of RPAs. By integrating the Maximum Entropy model (MaxEnt) with the Soil and Water Assessment Tool (SWAT), we assessed how climatic and hydrological variables shape the habitat range dynamics of the native fish Gymnodiptychus dybowskii ( G. dybowskii ) in the arid Kaidu River Basin of Xinjiang, northwest China, over the period 1980–2100, using five general circulation models and three CMIP6 climate scenarios (SSP1‐2.6, SSP3‐7.0, and SSP5‐8.5). Our findings indicated that the mean difference in monthly flow is the most influential hydrological variable, accounting for 60.4% of the relative contribution to habitat suitability for G. dybowskii , followed by temperature seasonality. This highlights the sensitivity of this species to hydrological variability in arid regions. Moreover, highly suitable habitats are projected to shift toward higher elevations, rising from a historical mean of 1835 m to 2198–2519 m in the future. The projected upward shift is predominantly influenced by the synergistic interactions among hydrological fluctuations, climate seasonality, and climatic characteristics of the dry season. This interaction results in the emergence of high‐altitude regions as potential future climatic refugia. Existing habitat conservation plans inadequately cover these potential refugial habitats, possibly threatening future fish population persistence. This study provides an important basis for developing adaptive biodiversity conservation strategies under climate change.