Thursday January 29, 2026
Phys —
A new study published in Communications Biology reveals a critical, yet previously overlooked, environmental consequence of man-made dams constructed across rivers and streams. By investigating a key indicator species of ecosystem health, the brown trout (Salmo trutta), researchers from the Estonian University of Life Sciences and the Swedish University of Agricultural Sciences demonstrated that small river impoundments significantly elevate water temperatures and drastically increase the pathogenic impact of Proliferative Kidney Disease (PKD).
The hidden hazard
Dams provide essential services for humans but profoundly alter river ecology. While issues like habitat fragmentation are well documented, the new findings focus on the complex interaction between dams, thermal regimes, and disease. The international research team examined juvenile brown trout and measured water temperatures both upstream and downstream of 14 small reservoirs and artificial impoundments.