Complex hydrophysical expedition on R/V G.Yu. Vereshchagin from July 21 to August 3, 2025
From July 21 to August 3, 2025, expeditionary works were carried out on R/V G.Yu. Vereshchagin within the State Assignments No. 0279 2021 0004 “Study of advective and turbulent water exchange...” (led by Aslamov I.A.), No. 0279 2022 0004 “Assessment of environmental and economic aspects…” (led by Makarov M.M.), and No. 0279 2019 0005 “Study of transformations of the state of water bodies...” (led by A.P. Fedotov).
The purpose of the expedition was to conduct comprehensive monitoring and assessment of the effects of advective and turbulent water exchange on the change in the Lake Baikal ecosystem, which determine the quality of its waters.
Work was carried out in three basins of the lake, as well as in Barguzinsky Bay and in Maloye More Strait. During the expedition, samples were taken using a standard grid of stations of longitudinal and transverse sections of the lake on fixed horizons from surface to bottom using a Carousel SBE-32 cassette-type sampler equipped with 24 bathometers with a capacity of 5-liters. Water samples were taken for chemical analysis and for the study of the spatial distribution of microalgae in the water area of Lake Baikal. Zooplankton samples were taken by a Juday net. Water samples were taken at 20 stations. Hydrophysical measurements were carried out at 73 stations with a high-precision CTD probe SBE-25 with additional sensors for dissolved oxygen, transparency and suspended matter concentration and a JFE-Rinko CTD probe at 66 stations. Total samples taken:
- Chemical analysis - 214
- Phytoplankton — 36
- Picoplankton — 96
- Zooplankton — 31
On the ship`s course, the temperature and electrical conductivity of the water, turbidity, Ph and ORP were recorded, as well as gas bubble outlets, which were monitored using a hardware-software complex based on a Furuno echo sounder with recording of echogram data.
The experiments with autonomous drifting buoys “Piligrim” of own design were carried out near Ivanovka settlement (106 km) in the area of the Neutrino Telescope and Cape Nizhnee Izgolovye of the peninsula Svyatoi Nos. The drifting trajectories and internal waves according to thermistor chains are obtained by installing 3m2 underwater sails at a depth of 4 m and 20 m.
At the Khakusy recreation center, the information collection and transmission system associated with the previously installed AGMS, which includes a lake level meter, has been upgraded. Additionally, the monitoring stations located at Cape Elokhin and near Uzury settlement received maintenance.
A deep-sea video recording of the bottom was conducted in the vicinity of the gas outlet “Melky” and at the mud volcano “Kedr” using equipment developed in collaboration with Research Institute of Applied Physics of ISU of Irkutsk State University.
A detailed hydrophysical study of the Proparina P5 gas outlet was performed. An up-to-date bathyorographical map of 2x2 km in the area of the gas outlet was generated.
