Studying the distribution of Ulva intestinalis (Chlorophyta, Ulvophyceae) in the rivers of the Kuibyshev, Saratov and Volgograd reservoirs basins

The article presents data on the distribution of Ulva intestinalis in the tributaries of the Lower Volga reservoirs. An assessment of the occurrence and relative abundance of the species in the studied rivers is given. Mineralization and water flow velocity are factors influencing the quantitative development of Ulva intestinalis. The structure of river phytoplankton communities in the areas of species development is considered. The features of longitudinal changes in the values of saprobity indices and relative abundance of Ulva intestinalis are shown using the example of the B. Irgiz River.