Abstract:
This study provides an in-depth characterization of the water quality in the Yesil River
in the Astana region for 2019, utilizing hydrochemical parameters and key indicators of
bacterioplankton, zooplankton, and zoobenthos. Quantitative evaluation methods were
employed to assess hydrobionts, including total bacterial counts, heterotrophic bacterial
counts, bacterial multiplication rates, biomass, and abundance of zooplankton and
zoobenthos, in addition to species identification for various organisms. The results
indicated that, based on the bacterioplankton development level, the investigated section
of the Yesil River is classified as a mesotrophic water body. As the river flows through
the city, the average bacterial mass doubling time decreases due to an increase in the
proportion of heterotrophic bacteria. Based on the saprobity index level for the
zooplankton community, the water in the Yesil River is categorized as moderately
polluted. Macrozoobenthos saprobity indices range from moderately polluted to polluted
waters. The final assessment of the water quality classification and contamination degree,
according to Z.G. Gold's unified classifier, revealed a shift from class 3 in the sections
upstream of Astana to class 4 in sections downstream of the city.
