Assessment of the quality of the surface waters of the Krynka River using biotesting and fluorimetry methods

The article considers the possibility of using fluorimetric analysis of photosynthetic activity of phytoplankton in assessing the toxicity of natural water samples by biotesting on Chlorella vulgaris culture. The study assessed the toxicity of water samples from the Krynka River, its tributaries – the Olkhovka and Olkhovaya Rivers, as well as the Khanzhenkovskoye, Olkhovskoye and Zuyevskoye Reservoirs, which are sources of water resources for the region. The inclusion of a fluorimetric assessment of the photosynthetic activity of phytoplankton cells using chlorophyll fluorescence induction curves makes it possible to study in more detail the change in the state of the test object. Biotesting was performed on a culture of green microalgae Chlorella vulgaris. The study revealed a decrease in the fluorescence intensity and photosynthetic index of algae cells when cultured on filtrate from all monitoring points. Acute toxic effects have been established for water samples from the Khanzhenkovskoye and Olkhovskoye Reservoirs, as well as chronic toxic effects for the Zuyevskoye Reservoir. The deterioration of surface water quality in reservoirs is associated not only with the ingress of mine waters, but also with intensive water use, which leads to a significant decrease in water levels and the death of aquatic organisms. The results obtained can become the basis for further monitoring studies of surface waters in order to identify and eliminate factors that have a negative impact on rivers and reservoirs in the region.