Expedition on board RV “G.Yu. Vereshchagin”, July 24 – August 04, 2018

The complex expedition within the framework of the programmes “Assessment and Forecast of Ecological State of Lake Baikal and Adjacent Territories under Conditions of Anthropogenic Impact and Climate Change” and “Studies of Evolutionary, Ecological and Molecular-Biological Aspects of Silica-Dependent Chromista as Main Members of Silica Cycle in Aquatic Ecosystems” was carried out on board RV “G.Yu. Vereshchagin”, July 24 – August 04, 2018 throughout the entire water area of Lake Baikal.

The expedition was aimed at studying influence of natural and anthropogenic factors on the change of abiotic and biotic characteristics of Lake Baikal ecosystem that determine its water quality.During the expedition, hydrophysical measurements were performed at 59 stations using high-precision CTE probe SBE-25 with an additional dissolved oxygen sensor. Water samples for hydrochemical analysis (methane concentration, dissolved oxygen and biogenic elements) were collected at fixed horizons from the surface to the bottom using the Carousel SBE-32 cassette sampler equipped with 25 barometers of 5-liters each. To study distribution and species composition of phytoplankton, the samples were collected with a Jedi net.

The researchers from Institute of Marine Biological Studies (Sebastopol) participated in the expedition. They studied spatial distribution of the chlorophyll-a concentration, the change in the spectral composition of light within the zone of photosynthesis, as well as vertical distribution of the main photosynthetic characteristics of phytoplankton within the zone of photosynthesis.

Along the RV course, water surface temperature and known gas bubble seepages were monitored using a software and hardware system based on the Furuno echo sounder with continuous recording of echogram data.