Field work on the R/V “Titov” from May 29 to June 9, 2024
Field work was carried out within the State assignments No. 0279 2021-0005 “Study of transformations of the state of water bodies and watercourses of Eastern Siberia in seasonal and long-term aspects in the context of climate change, geological environment and anthropogenic loads” (led by Fedotov A.P.), No. 0279-2021-0010 “Genetics of communities of Baikal organisms: gene pool structure, conservation strategies” (led by D. Yu. Shcherbakov), and No. 0279-2021-0015 “Study of viral and bacterial communities as the basis for the stable functioning of freshwater ecosystems and an effective response in conditions of anthropogenic impact” (led by O. Belykh).
Field work was carried out within the State assignments No. 0279 2021-0005 “Study of transformations of the state of water bodies and watercourses of Eastern Siberia in seasonal and long-term aspects in the context of climate change, geological environment and anthropogenic loads” (led by Fedotov A.P.), No. 0279-2021-0010 “Genetics of communities of Baikal organisms: gene pool structure, conservation strategies” (led by D. Yu. Shcherbakov), and No. 0279-2021-0015 “Study of viral and bacterial communities as the basis for the stable functioning of freshwater ecosystems and an effective response in conditions of anthropogenic impact” (led by O. Belykh).
In order to monitor the disease status of the Baikal endemic sponges, a quantitative collection of diseased individuals was conducted along the previously established sites. As a result of this sampling, the distribution of affected species along the lake areas will be analyzed, taking into account the species affiliation of the sponges. To analyze the diversity of viruses within the associated communities and to assess the current status of the Baikal endemic sponges, samples of diseased and healthy sponges Lubomirskia baikalensis were collected.
To obtain year-round information on the temperature regime in the bottom layer in the shallow water of the lake, logger readings were taken on the installed transects (at depths of 4, 6, 12, and 15 meters). Loggers were installed on transects at a depth of 30 meters.
Besides, samples of benthic biofilms were taken from a variety of substrates in order to clarify data on the species diversity of benthic cyanobacteria in Lake Baikal and to obtain cultures of dominant species for further studies. Obtaining pure cultures of cyanobacteria will allow us to clarify their taxonomic status (some of them are probably new species) and identify species producing cyanotoxins (microcystin and saxitoxin) and biologically active substances.
Fouling on substrates of both biotic origin (sick sponges Lubomirskia baikalensis, submerged macrophytes, mollusk shells) and abiotic origin (sand, stones, rocky outcrops, wood, fishing nets, plastic) was studied. For the first time, we observed sponges fouling with large (3 cm) brownish-white colonies of the diatom alga Didymosphenia geminata.
During the expedition, representatives of the order Amphipoda were collected and recorded from different areas of the lake. All specimens collected will be subjected to species identification, DNA extraction for population genetic analysis, and the detection of tRNA gene remolding at the population level.
Underwater tests and test shooting with the camera "Sony A7 III" with a new port for the box were carried out; the first photos are attached to the report.