Assessment of the impact of military actions on aquatic ecosystems

The article examines the complex and cumulative impact of military actions on the state of aquatic ecosystems in Ukraine under conditions of prolonged armed conflict and continuous anthropogenic pressure. The main mechanisms of pollution of water bodies by toxic components of explosives, heavy metals, and products of ammunition degradation are considered. It is shown that, once introduced into the aquatic environment, these substances form persistent xenobiotics that accumulate in trophic chains, disrupt the metabolic processes of hydrobionts, and reduce the natural self-purification potential of water bodies. Based on the results of long-term field monitoring studies of a section of the Dnipro River within the urban ecosystem of Kyiv (river profile 922-825 km), a spatial analysis of the dynamics of hydrochemical and hydrobiological indicators was carried out. A pronounced deterioration in the ecological state of the aquatic ecosystem downstream within the urbanised profile was established, with the maximum occurring in the zone affected by the discharges from the Bortnychi Aeration Station. This is manifested in a decrease in dissolved oxygen content, an increase in organic and nutrient loading, and the exceedance of standards for ammonium nitrogen content. In addition, a reduction in phytoplankton species diversity was recorded, with the dominance of pollution-tolerant cyanobacteria, in particular the toxin-producing species Microcystis aeruginosa. The calculated indicators, in particular the integral techno-capacity index and the index of the intensity of internal water-body processes, made it possible to quantify the cumulative nature of river ecosystem degradation and the reduction of its assimilative capacity. Based on the research results, a system of parameters for assessing the structural and ecological transformation of watercourses, a classification of the main factors of cumulative impact, and a phased model for the restoration of degraded aquatic ecosystems are proposed. The proposed scientific and methodological approach is of practical importance for improving environmental monitoring, assessing ecological risks, substantiating priority environmental protection decisions, and planning measures for the post-war rehabilitation of water resources.