Expedition on board the R/V “Papanin” on July 16-28, 2023
On July 16-28, 2023 the complex field works on board the R/V “Papanin” were carried out within the State assignment “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) (led by A.P. Fedotov).
The expedition was aimed at studying the processes of river flow transformation in the mixing zone “Verkhnyaya Angara River – Lake Baikal” and the current chemical and biological status of small tributaries of Lake Baikal. Within the expedition, samples of water and bottom sediments were taken at the mouths of 80 rivers flowing into Baikal. Water samples were taken for chemical (pH, electrical conductivity, oxygen content, concentrations of major ions, biogenic elements, microcomponents and organic matter), microbiological (abundance of organotrophic bacteria, generalized and thermotolerant coliform bacteria, E. coli and enterococci) analyses, as well as for determining the abundance and species diversity of phytoplankton. In addition, river water samples were taken for isotope analysis. Small tributaries of the lake are poorly studied, the most complete data on chemical composition of the river waters were collected in the middle of the last century (Votintsev et al., 1963), and there is no information on bacterio- and phytoplankton for most rivers. The materials obtained during the expedition enable to expand knowledge about chemical and biological composition of river waters in the Baikal basin and reveal possible changes that occurred over 60-70 years under the influence of natural and anthropogenic factors.
The study of river flow transformation processes in “river-lake” mixing zones, which was started earlier in the mouth reaches and adjacent shallow waters of the Selenga and Barguzin Rivers, was continued. To determine the zone of active transformation of substances entering Baikal with river water, water samples were taken in the delta of the Verkhnyaya Angara River and in the Angara-Kichersky shallow water area at three transects from the Dagarskaya, Srednaya and Kicherskaya breaches (Yarki Island). Water was sampled for chemical and microbiological analysis at different horizons from surface to bottom using a bathometer. Bottom sediments were sampled with a dredge in the shallow water.
The staff of Laboratory of Hydrochemistry and Atmosphere Chemistry (Tomberg I.V., Bezborodova Y.V., Loginova E.D.), Laboratory of Interdisciplinary Environmental and Economic Research and Technologies (Podlesnaya G.V., Stepanova O.G.) and Informational-analytical department (Tyurnev I.N.) participated in the expedition.
The expedition participants thank the crew of the R/V “Papanin” for their good and well-coordinated work.
