The results of a research into the scale and consequences of the degradation of aquatic ecosystems in Ukrainian Polesie have been detected in article, and the areas of increased anthropogenic pressure have been identified which greatly affect the condition and number of aquatic macrophytes. The biodiversity of sites with different anthropogenic load was evaluated using the biodiversity criteria. In the research, the structural and functional features of macrophytic species diversity within Teteriv River ecological corridor as a typical river landscape of Ukrainian Polesie were determined and described, the floristic composition was determined. Within the ecological zones, the number of species and their projective coverage in areas with different anthropogenic pressures within Teteriv River ecological corridor were determined. The basic criteria for the implementation of deferred biomonitoring based on the analysis of the dynamics of the spe-cies composition of the phytocoenoses of Teteriv River ecological corridor on the indicators of ecological stability and plasticity using the species-specific criteria, are: Margalef species richness index, Sørensen–Dice index, Shannon diversity index, Simpson’s index, and Pielou’s evenness index. Based on the results, correlation dependencies have been constructed, which will allow to obtain data on the stability of the development of aquatic ecosystems according to the data of species surveys. Interconnections between biodiversity indicators and indicators of surface water quality within the Ukrainian Polesie were found; they are the fundamental component of a long-term monitoring of the stability in the development of aquatic phytocenoses.

The research analyzed seasonal changes of the oxygen regime and related indicators on the example of water objects of the Ukrainian Polesie Region. The region shows different directions of economic use. Zebrafish ( Danio rerio Hamilton–Buchanan) and the Prussian carp ( Carassius auratus gibelio Bloch) were used as test objects to investigate survival responses. Dissolved oxygen (DO) concentration in water, pH values and temperatures were determined by standard methods. Based on research results, the main problems were determined pertaining to the oxygen regime of investigated waters, i.e. the increase in temperature and toxicity of the aquatic environment in the summer. A rather dangerous decrease in DO concentration, almost up to the levels of maximum allowable concentration (MAC) (4.10 mg∙dm–3 in group E1 and 6.07 mg∙dm–3 in group E2), was observed in August and it was typical for the reservoirs with a slow water movement. Flowing river waters (group E3) were eliminated due to their better aeration compared to other groups. The correlation analysis based on the presented data revealed a high and average degree of probable correlation between the DO concentration and water temperature, as well as an average degree of correlation with general toxicity determined on sensitive species of D. rerio, and in group E1 on the persistent species C. auratus gibelio as well. The interrelations and equations of the rectilinear regression can be used to predict the oxygen regime of the waters investigated and other surface waters having similar problems.