Below are five graphs with observations of 5 groups of hydrobionts in lake Baikal in 2021, and in 2015-2020 for comparison. The x-axis shows the months of 2015-2021, and the y-axis shows the average value of the population or the total mass index for the time of observation. Each chart has the dash-lines consisting of horizontal lengths of the survey time (1-3 months)

During 2021, the average quantitative indicators of groups of hydrobionts in the area of the Baikal SPIT, in the area of the BAM highway and in the Selenginsky shallow water of Lake Baikal are comparable with the values of previous years. There were no trends to increase or decrease the parameters.

In the Selenginsky shallow water area in September 2021, the amplitude of phytoplankton abundance varied from 255.5 to 1920.5 thousand cells/l, biomass – from 96.1 to 675.8 mg/m3. The total average number, relative to last year, increased 1.6 times and reached 1371.3 thousand cells/l; biomass, on the contrary, decreased 1.4 times – up to 394.6 mg/m3.

In the area of Northern Baikal, zooplankton abundance indicators varied in the range of 4.49–47.01 thousand copies/m3, biomass – 31.04–1284.67 mg/m3.