Expedition on the RV Papanin on June 1-12, 2026

Works were carried out within the State Assignment № FWSR-2026-0015 “Influence of Abiotic Factors of Lake Baikal and Adjacent Territories of Eastern Siberia on the Adaptation and Biodiversity of Aquatic Organisms at the Level of Ecological, Biochemical and Molecular Genetic Characteristics” (led by Fedotov A.P.).

The tasks of the expedition included the study of hydrochemical parameters and the distribution of phytoplankton in the shallow zone of Lake Baikal. The average sampling step along the perimeter of Lake Baikal was every 30-50 km.

In spring 2026, South Baikal ice melted very early, by early May, but North Baikal still had ice on it at the end of May; it was unique for this season. For example, on June 4, 2024, at the station in Frolikha Bay, the water temperature was 5.3 °C, and the transparency by the Secchi disk was 11 m; on June 5, 2026, these indicators were 2 °C and 7 m, respectively. As a result, intensive phytoplankton blooming was in Northern Baikal. In general, it should be noted the low transparency throughout Lake Baikal - an average of 4-7 m, while in previous years it was 9-12 m. Previously, the maximum transparency values reaching 30 m were recorded near the settlement of Bolshye Koty, but in 2026 this parameter was only 11 m.

According to preliminary data, representatives of the genera Aulacoseira, Synedra, Stephanodiscus, prevailed among planktonic diatoms, and species of the genus Dinobryon yellow-green algae..