Impact of Fish Ponds on Stream Hydrology and Temperature Regime in the Context of Freshwater Pearl Mussel Conservation

Conservation of endangered, cold-stenothermic species, such as the freshwater pearl mussel (FPM) and its salmonid host fish, are particularly challenging in headwater streams their last refuge areas. Understanding impact anthropogenic catchment features fish ponds on hydrology temperature regime is, therefore, important. In this study, runoff a FPM with more than 150 small was simulated using SWAT compared to scenario without ponds. Additionally, water monitored hourly along three steams over 2.5 years, at sites upstream downstream inflow pond outlet channels. Temperature metrics were related land use within 180 m corridor streams. Peak flows reduced by 1.5% ponds, while low increased 4.5%. summer, effluents higher receiving stream, depending proximity points. Discharge from close-by summer stream directly up 5.5 °C. These temperatures partly compensated groundwater contribution forested contrast, significantly further stretches flowing through open land, persisting independently inflows. We suggest incorporating knowledge pond- use-dependent effects regimes into conservation management other well climate change mitigation strategies targeting an resilience against extremes.