Horoshkova, LidiіaZaitsev, VolodymyrRyshykov, IgorShovkoplias, T.2025-11-052025-11-052025Environmental Impacts of Dredging Operations on the Condition of Surface Waters of the Danube River / L. Horoshkova, V. Zaitsev, I. Ryshykov, T. Shovkoplias // XVIII International Scientific Conference "Monitoring of Geological Processes and Ecological Condition of the Environment", 14-17 April 2025, Kyiv, Ukraine. - [S. l.] : European Association of Geoscientists & Engineers, 2025. - Vol. 2025. - P. 1-5. - https://doi.org/10.3997/2214-4609.2025510189https://doi.org/10.3997/2214-4609.2025510189https://ekmair.ukma.edu.ua/handle/123456789/37380The conducted analysis allowed determination of the main factors influencing the quality of surface waters in the estuarine part of the Danube River. The hypothesis regarding the absence of environmental threats from dredging operations conducted by Ukraine in the Bystre estuary of the Kiliya marine delta of the Danube was confirmed. It has been proven that as a consequence of water management measures implemented by Romania, the annual average discharges of the Tulcea branch and Sulina estuary increased, while the water discharge of the Kiliya branch significantly decreased. The consequence was a significant deterioration of ecological conditions in the Ukrainian Danube region, manifested by an increase in the content of biogenic elements and periodic decreases in oxygen content. In contrast, with the start of dredging operations and increased water discharge through the Bystre estuary, the dissolved oxygen content became stable while the BOD5 level decreased (below MPC), indicating improved water quality. Although simultaneously, navigation activity through the estuary increased significantly, and the ammonium ion level significantly increased. The year 2024 became critical for the dissolved oxygen level, when the phosphate ion content significantly increased, despite the fact that the ammonium ion content decreased to the 2019 level. Thus, the analysis results confirm the conclusion that the decisive factor affecting water quality in the Danube River is not navigation. Therefore, there is a need for further research regarding the impact of other pollutants and their sources, beyond those analyzed, on the condition of the Danube River surface waters.enDanube Riversurface watersUkrainian Danube regionwater quality in the Danube Riverconference materialsConference materials