ASSESSMENT OF WATER QUALITY OF URBANIZED TERRITORIES ACCORDING TO THE STRUCTURE OF HYDROBIONT GROUPS

Abstract

The paper proves the possibility of conducting water quality assessment using such an indicator as the species assemblage of Unionidae habitats for the purpose of conducting local bioindication. According to the species assemblage of Unionidae habitats, it was established that of the five analyzed sites of material collection of the main stream of the Teteriv River, in one case the water quality can be assessed as "Dirty", which corresponds to the IV water quality class, and in three cases as "Contaminated", which corresponds to the III class, and in another one - as "Good" - II class of quality. The rivers Guiva (Ivankiv), Kroshenka and Putyatinka within Zhytomyr belong to the IV class of water quality. Five more points are assigned to the II quality class (Guyva River in the area of Pryazhevo and Zarichany villages; Kam'yanka River (Zhytomyr); Kodenka River (Vertokiyivka village) and Hnylop'yat River (Berdychiv).More detailed information about the ecological state of aquatic ecosystems is provided by the use of algal communities of plankton as biological descriptors, but this approach is time-consuming. In general, the bioindication of water quality in the rivers of the Teteriv basin according to phytoplankton showed the predominance of indicators of saprobity, which correspond to the III class of water quality ("Contaminated"). Class II ("Good") indicators make up a significant share. A moderate level of organic water pollution is indicated by the predominance of eurysaprobes in the rivers. In terms of phytoplankton biomass, the Teteriv and Kroshenka rivers belong to the III class of water quality, other watercourses belong to the II class. According to the saprobity index, the water quality of the Teteriv, Putyatinka, and Kroshenka rivers is rated as satisfactory, and that of other watercourses as good. According to primary production and the ratio of production and destruction processes, watercourses were ranked into three groups - those belonging to II, III and IV water quality classes. The average values of the integral index ∑А/∑R for all watercourses, except for the Putyatinka River, are higher than 1. This indicates a positive balance of organic matter, characteristic of aquatic ecosystems with a high intensity of photosynthesis. The predominance of the heterotrophic phase in Putyatynka is most likely a response of the watercourse ecosystem to anthropogenic pressure.A comprehensive assessment of the water quality of watercourses in urbanized areas using as biological descriptors the ecological state of hydroecosystems of algae, plankton and mollusk settlements is the foundation for further ecological monitoring of waters, forecasting changes in the autotrophic and heterotrophic links of aquatic ecosystems under the influence of environmental factors.