Scientific publications

In May, July and October 2024 and 2025 phytoplankton studies were conducted in Lake Uzkoye, located in the selga-ridge landscape of the north-western Ladoga region. The lake is characterized by stable thermal and oxygen stratification, with the monimolimnion featuring temperature constantly at around 4 °С and an anoxic zone. The phytoplankton species composition comprises 80 algal taxa ranking below genus. Chlorophytes, diatoms, and euglenophytes were the most diverse groups in terms of the number of taxa. 45 taxa were recorded in quantitative samples. The highest abundances were exhibited by chlorococcales in chlorophytes, Closterium acutum in charophytes, and flagellates in cryptophytes, chrysophytes, euglenophytes, and dinoflagellates, capable of vertical migration through a strongly stratified water column. It was only in the spring that peak algal development was observed in the surface layer. In the summer and fall, the biomass was the greatest above the thermocline, at 4–6 m depths. The monimolimnion was nearly free of phytoplankton. Over the two-year period of observations in Lake Uzkoye, the weightedaverage phytoplankton biomass in the trophogenic layer (0–6 m) ranged seasonally from 0.7 to 1.8 g/m³. In 2024, the highest values were recorded in summer, whereas in 2025 they occurred in spring, which was determined by different weather conditions. The approximate seasonal averages of phytoplankton biomass were similar in the two years, about 1 g/m³, suggesting Lake Uzkoye can be classified as mesotrophic.