The article presents data on the assessment of the state of higher aquatic plants cooling reservoir Balakovo NPS under the influence of biomeliorative fishes. It was revealed that the species diversity of higher aquatic vegetation for the period of study has sharply decreased from 34 (2009) to 12 species (2015). The dominant species, which defines the image of plant communities, is common reed (Phragmites australis (Cav.) Trin. Ex Steud). Reed communities are rated as very highly productive in terms of net primary production.
