Expedition on board the RV “Papanin” from 16 to 27 September, 2022
From 16 to 27 September 2022, the expeditionary works were carried out on the board the RV “Papanin” to study the ecological state of the coastal zone of Lake Baikal within the programmes “Study of seasonal and long-term transformations of the state of water bodies and watercourses in East Siberia in the context of climate change, geological environment and anthropogenic loads” (project № 0279-2021-0005) (directed by A. Fedotov) and “Studies of the influence of atmospheric precipitation onto water and land ecosystems of Lake Baikal, identification of atmosphere pollution sources” (project № 0279-2021-0014) (directed by T. Khodzher).
The expedition was aimed to study: the hydrochemical parameters of the shallow water zone of the lake, the distribution of the phytoplankton, zooplankton and zoobenthos. The samples were taken every 30-50 meters along the Lake Baikal perimeter. Plankton samples were collected using a bathometer, Apstein nets, and Juday nets. Zoobenthos samples were taken by hydrobiological net during diving works.
As a result, there were collected 48 quantitative zooplankton samples, 68 quantitative and 49 qualitative phytoplankton samples at 47 stations from depths up to 50 m and 3 pelagic stations. Water transparency was measured at each station using a Secchi disk. Sixty-eight surface water samples were taken for hydrochemical analysis for direct analysis and fixation followed by determination of the ionic composition and content of biogenic elements in the laboratory. Within the expeditionary works, there were measured temperature, pH, conductivity, hydrocarbonate content, and dissolved oxygen in water samples. The minimum water temperature was 5.1 ° C, which was recorded near the Kultuk settlement, and the maximum temperature – 13.3 ° C fixed in Barguzin Bay. The average temperature was 10.2 ° C. Water samples for further laboratory analysis for polybrominated diphenyl ethers and o-phthalic acid diesters were taken at seven stations including sites of the river mouths near the settlements. Sixty-five surface water samples were collected for isotopic composition determination.
Zoobenthos samples were taken at 13 sites from depths of 5, 10, 15, 20, 30 m and fixed representatives of copepods - harpacticoides and cyclopids in laboratory conditions. In addition, copepods (ectoparasites of the Baikal ichthyofauna) were collected and fixed to study the horizontal transfer of genetic mobile elements.
