The Content of Chlorophyll and Its Relation to Biogenic Elements of the Pelagic Zone of Lake Baikal

Based on the results of long-term field measurements (2018-2023), the variability of concentrations of chlorophyll and biogenic elements in the pelagial of Lake Baikal was studied. Over the study period, the average concentration of chlorophyll in the upper 100-meter layer of lake water is 1,32 µg/L. Two types of vertical chlorophyll a distribution are considered depending on the type of temperature stratification and the depth of the thermocline. The interannual and intraannual changes in the concentration of chlorophyll in the upper layer of water and their relationship to the dynamics of biogenic elements are evaluated. The Carlson trophic index (TSI) has been calculated, and the obtained values indicate that the pelagic zone of Lake Baikal belongs to the oligotrophic type of water bodies.