Why have Dnieper River dams made it harder for anadromous fish to move upstream?

The construction of dams along the Dnieper River has significantly altered the river's natural hydrology and ecology, creating physical barriers that impede the movement of anadromous fish. By damming the river to create reservoirs for hydroelectric power and water management, the natural pathways used by migratory species to reach their upstream spawning grounds have been obstructed.1

These structures have fundamentally changed the river's environment, leading to a reduction in upstream access for fish that migrate from the sea to spawn in freshwater. While some engineering solutions, such as fish passes, are designed to help fish navigate around such obstacles, the cumulative impact of multiple dams on a single river system often makes it difficult to sustain migratory fish populations effectively.12