FISH MIGRATION PARTICULARITIES BETWEEN THE NISTRU RIVER AND THE RĂUT RIVER

This study investigates the particularities of fish migration between the Răut and Bâc rivers and the Nistru River, within the context of the severe degradation of aquatic ecosystems in the Republic of Moldova. Hydromorphological changes, pollution, and the fragmentation of watercourses have caused significant alterations in the structure and functioning of fish communities, particularly affecting native reophilic and migratory species. Ichthyological studies conducted between 2024 and 2025 highlight high diversity in the lower sector of the Răut River (31 species), compared to the Bâc River (9 species), where the fish community is highly simplified and dominated by pollution-tolerant species. The results highlight the important role of the Nistru tributaries in supporting fish migration and conserving biodiversity, and the negative impact of human pressures on these processes. Finally, management and ecological restoration measures are proposed, including the restoration of longitudinal connectivity, improvement of water quality, and protection of spawning areas, to ensure the conservation of fish resources and the sustainable functioning of aquatic ecosystems.