High-altitude aquatic ecosystems are experiencing rapid environmental change as climate warming accelerates faster in mountain regions than the global average. This review brings together current understanding of how these shifts influence fish through both direct environmental pressures and indirect ecological consequences. Rising temperatures, altered hydrological regimes, glacial retreat, and frequent extreme climatic events are altering the physical characteristics of high-altitude rivers and lakes. These changes disrupt thermal regimes, oxygen availability, flow patterns, and habitat connectivity, resulting in conditions that challenge the survival of coldwater fish. Beyond these immediate effects, climate change drives a set of indirect effects, including range shifts, altered migration behaviour, irregularities in reproductive timing, disease outbreaks, biodiversity loss, and changes in ecosystem functioning. The physio-phenological mechanisms that control fish responses to temperature variations and hydrological changes brought on by climate change in high-altitude settings are summarized in this review. Understanding these dynamics is crucial for managing cold-water fish populations, evaluating population resilience, and developing adaptive conservation plans in the face of rapidly warming world.
Saima et al. (2026) studied this question.