Interannual dynamics of the Ural River phytoplankton and different-type stretches of the Iriklinsky reservoir in spring

Abstract

Our study revealed that water temperature and total atmospheric precipitation played the leading role in the interannual dynamics of phytoplankton in the unregulated section of the Ural River in spring of 2016–2019. With rise in water temperature, the concentration of nutrients and organic matter increased. In the Iriklinsky reservoir, the phytoplankton development depended on arrival of substances from the catchment, however, the cumulative effect of the ratio of major hydrological parameters and the total atmospheric precipitation was crucial. Due to this, the periods of the maximum quantitative development of the communities in each stretch differed in time. Phytoplankton transformation was diverse and hinged on the influence of the main river, including morphometric parameters of sites. For instance, most statistically significant changes in the studied parameters were recorded in the river and the upper reaches, while the least – in the low reaches of the reservoir.

Keywords

• algae
• weather conditions
• hydrological characteristics
• specific number of species
• biomass
• mixotrophic phytoflagellates
• average single-cell mass
• organic matter
• nutrients