Baikal Research Articles

Underwater discharge of fluids at the bottom of lake Baikal: composition, sources and migration peculiarities within the MSU structure

The paper presents geochemical study of bottom sediments from the MSU structure located on the large Gydratny Fault in the Central Basin of Lake Baikal at a depth of 1380 m. The first detailed data on the spatial variations in the qualitative and quantitative composition of the pore waters are presented. Pioneering data were obtained on Li, B, and Sr contents in the pore water of the sediments. It has been established that fluids are actively discharged within the MSU structure, and the main pathways of their near-surface migration are confined to the tops of hills of this structure on the downthrown fault block. The fluids are highly mineralized (up to 2900 mg/L), showing the highest mineralization ever found in Lake Baikal sediments. The waters are significantly enriched in Mg, Li, B, and Sr but depleted in K. The waters are thought to be generated by the processes of authigenic formation and illitization of smectite at depths of 1 to 2.5 km in the sedimentary sequence. The maximum values of concentration gradients are recorded in the pore waters of the sediments of the western hill, which may indicate a gradual westward shift of the center of the fluid seepage activity along the fault.

New Bacteriophage Pseudomonas Phage Ka1 from a Trivia of Lake Baikal

New Bacteriophage Pseudomonas Phage Ka1 from a Trivia of Lake Baikal

UV Sensitivities of Two Littoral and Two Deep-Freshwater Amphipods (Amphipoda, Crustacea) Reflect Their Preferred Depths in the Ancient Lake Baikal

Solar ultraviolet (UV) is among the most important ecological factors shaping the composition of biota on the planet’s surface, including the upper layers of waterbodies. Inhabitants of dark environments recently evolving from surface organisms provide natural opportunities to study the evolutionary losses of UV adaptation mechanisms and better understand how those mechanisms function at the biochemical level. The ancient Lake Baikal is the only freshwater reservoir where deep-water fauna emerged, and its diverse endemic amphipods (Amphipoda, Crustacea) now inhabit the whole range from highly transparent littoral to dark depths of over 1600 m, which makes them a convenient model to study UV adaptation. With 10-day-long laboratory exposures, we show that adults of deep-water Baikal amphipods Ommatogammarus flavus and O. albinus indeed have high sensitivity to environmentally relevant UV levels in contrast to littoral species Eulimnogammarus cyaneus and E. verrucosus. The UV intolerance was more pronounced in deeper-dwelling O. albinus and was partially explainable by lower levels of carotenoids and carotenoid-binding proteins. Signs of oxidative stress were not found but UV-B specifically seemingly led to the accumulation of toxic compounds. Overall, the obtained results demonstrate that UV is an important factor limiting the distribution of deep-water amphipods into the littoral zone of Lake Baikal.

Genomic Insights into the Bactericidal and Fungicidal Potential of Bacillus mycoides b12.3 Isolated in the Soil of Olkhon Island in Lake Baikal, Russia

Genomic Insights into the Bactericidal and Fungicidal Potential of Bacillus mycoides b12.3 Isolated in the Soil of Olkhon Island in Lake Baikal, Russia

Composition and Distribution of Macroinvertebrates Associated with the Sponges Lubomirskia baikalensis (Spongillida, Lubomirskiidae) during the Ecological Crisis in Lake Baikal

Composition and Distribution of Macroinvertebrates Associated with the Sponges Lubomirskia baikalensis (Spongillida, Lubomirskiidae) during the Ecological Crisis in Lake Baikal

Congruent and Hierarchical Intra-Lake Subdivisions from Nuclear and Mitochondrial Data of a Lake Baikal Shoreline Amphipod

A central goal of molecular studies on ancient lake faunas is to resolve the origin and phylogeny of their strikingly diverse endemic species flocks. Another equally intriguing goal is to understand the integrity of individual morphologically diagnosed species, which should help to perceive the nature and speed of the speciation process, and the true biological species diversity. In the uniquely diverse Lake Baikal amphipod crustaceans, molecular data from shallow-water species have often disclosed their cryptic subdivision into geographically segregated genetic lineages, but the evidence so far is mainly based on mitochondrial DNA. We now present a lake-wide parallel survey of both mitochondrial and multilocus nuclear genetic structuring in the common shoreline amphipod Eulimnogammarus verrucosus, known to comprise three deep, parapatric mtDNA lineages. Allele frequencies of seven nuclear allozyme loci divide the data into three main groups whose distributions exactly match the distributions of the main mitochondrial lineages S, W, and E and involve a further division of the W cluster into two subgroups. The inter-group differences involve one to four diagnostic loci and additional group-specific alleles. The transition zones are either abrupt (1 km), occur over a long segment of uninhabitable shoreline, or may be gradual with non-coincident clinal change at different loci. Mitochondrial variation is hierarchically structured, each main lineage further subdivided into 2–4 parapatric sublineages or phylogroups, and patterns of further local segregation are seen in some of them. Despite the recurring observations of cryptic diversity in Baikalian amphipods, the geographical subdivisions and clade depths do not match in different taxa, defying a common explanation for the diversification in environmental history.

Morphogenetic Features of Soils on the Coast of the Svyatoy Nos peninsula (Eastern Baikal region)

The soils of the western coast of the Chivyrkuisky and Barguzinsky bays on the Svyatoy Nos Peninsula, the largest peninsula on Lake Baikal in the Republic of Buryatia, were studied. The morphogenetic characteristics of soils on the main types of coasts of the peninsula are given: low abrasion with isolated lagoons, low abrasion, accumulative and ingression. An important factor in the formation of soils is the differences in the rocks that make up the coasts of the bays. It is shown that the genesis of soils is determined by proximity to the lake and altitudinal location, which determines the difference in their structure and properties. Due to the high mountainous coasts, often rocky with steep slopes, the soils are not directly affected and flooded by lake water. The development of soils outside the floodplain regime is also typical for the soils closest to the lake level – sod-podzols, which occupy low accumulative types of shores. The studied soils revealed a wide range of granulometric composition: from loose sand to light clay. Similar properties of soils are the acidic and weakly acidic reaction of the environment, the regressive-accumulative nature of the distribution of humus content, and the differentiation of bulk oxides along the profile. Signs of podzolization in alpha-humus soils and clay formation in brown soils were diagnosed, due to sufficient moistening of the coasts and the warming influence of the lake’s water mass. The research results can be used in landscape planning in territorial organization and monitoring work in recreation areas.

Parasite Fauna of Sand and Stone Sculpins (Scorpaeniformes, Cottidae) from Lake Baikal (Review of Results and Prospects of Investigations)

Parasite Fauna of Sand and Stone Sculpins (Scorpaeniformes, Cottidae) from Lake Baikal (Review of Results and Prospects of Investigations)

On a finding of <i>Arocatus rufipes</i> Stål (Heteroptera, Lygaeidae) on the European white elm in Irkutsk

In the summer of 2023, a true bug Arocatus rufipes Stål, 1872 was detected on the European white elm in Irkutsk, which does not occur in natural environment in Siberia and is used for landscaping urban areas. The western boundary of the natural range of this Asian Heteroptera species runs in Buryatia. Currently, the species is probably spreading west of the Lake Baikal due to urban plantings using trees of the genus Ulmus.

National Tourism Policy in the Russian Far East of Russia: a Case Study of the Republic of Buryatia

The development of tourism in the Russian Far East is a priority for the strategic development of Russia in the current geopolitical environment. The state is implementing unprecedented measures to support the tourism industry in this macro-region. This article analyzes the implementation of the federal agenda for comprehensive tourism development in the Far East, using the Republic of Buryatia as an example (the republic is located in the Baikal natural territory and has been part of the Far Eastern Federal District since 2018). This article presents the key measures of state tourism policy for the Far East, as well as the mechanisms of state regulation and support of tourism in Buryatia. It demonstrates the changing territorial structure of tourism and recreational activities in the region. The study is based on legislative and regulatory documents, national projects, state programs, scientific publications and websites, as well as official statistical data from both federal and regional sources. The results of this study indicate that the Republic of Buryatia is actively enhancing its regional policy on tourism development by utilizing innovative approaches and progressive state support measures. Tourism in Buryatia has not only successfully overcome the consequences of the pandemic but is also developing in current conditions. This is evident in the prioritization of tourism in the Russian Far East and the significant efforts of the authorities of Buryatia, who participate in all competitive selections for federal financial support. At the same time, a significant increase in the number of accommodation facilities and tourist flow without insufficient consideration of environmental factors in investment and economic activities may manifest itself in increased environmental degradation. The article proposes measures to improve tourism policy in line with the solution of strategic tasks of tourism development in the Republic of Buryatia and the preservation of the unique ecosystem of Lake Baikal.

The Influence of Waters of Lake Baikal on the Spatiotemporal Dynamics of Phytoplankton in the Irkutsk Reservoir

On a model natural object, the Lake Baikal–Angara River–Irkutsk Reservoir (IR), we studied changes in the qualitative and quantitative characteristics of phytoplankton communities over three seasons in 2023 depending on seasonal changes in habitat parameters. Of the 151 identified taxa, Chrysophyta (57), Chlorophyta (41) and Bacillariophyta (24) predominated in diversity. Over the entire observation period, the highest values of total biomass and total abundance were detected in the IR in June (hydrological spring) at a water temperature of 10.0–12.7 °C, and the lowest in August, despite the fact that the water warmed up to 20 °C. No mass blooms of Cyanobacteria were observed. Statistical analysis of species abundance profiles revealed that phytoplankton community structure varied across time and space. The direct effect of cold lake waters on the structure of phytoplankton in the reservoir was observed only in early June. In summer and autumn, the structures of phytoplankton in the lake and in the reservoir differed, even at the same water temperature. Low concentrations of phosphates and nitrates, high species diversity, the presence of cold-water species and species with a wide range of temperature preferences formed a dynamic spatiotemporal structure of IR phytoplankton, distinct from other temperate reservoirs, including Lake Baikal. The results obtained are important for understanding the mechanisms of formation of the flora of artificial reservoirs of temperate latitudes and for their monitoring, taking into account seasonal dynamics and the context of global climate warming.

Morphological, ecological and genetic characteristics of the sandy sculpin (<i>Leocottus kesslerii</i>, Cottidae) from the lakes Baikal, Arakhlei and Gusinoe, Transbaikalia

Studies on local forms of the Sandy sculpin, Leocottus kesslerii, in the lakes Baikal, Arakhlei and Gusinoye show that the differences between lake forms in terms of external morphology lie in the head length to width ratio. In the Baikal form, the head is wider than long, vs the opposite in both Apakhlei and Gusinoe forms. In the Baikal and Gusinoe forms, there is a gap between the dorsal fins, a gap being absent from the Arakhlei form and the dorsal fins are in touch with each other. In the Arakhlei form, the anal fin is long (37.4–43%, on average 39.3% SL). In the Baikal form, the length of the A base reaches 32.9% SL (29.0–34.5%). In the Baikal and Arakhlei forms, small and sparse bone prickles are present on the body, these being large and dense in the Gusinoe form. The differences identified show a low level of morphological isolation of the forms. More significant differences are established in ecological features: growth rate, food spectrum, reproductive characteristics, and fecundity values. The differences in ecological features are due to the adaptation of the Sandy sculpin forms to specific conditions of the lakes they inhabit. Studies on genetic differentiation were carried out using the control region (CR) of mtDNA. The study forms of the Sandy sculpin revealed weak genetic isolation. The p-distances between the L. kesslerii forms averaged from 0.33 ± 0.12 to 0.51 ± 0.24%. Such low values of genetic distances clearly lie within the limits of intraspecific variability. The data obtained on the morphological, ecological and genetic differentiation of lake forms of the Sandy sculpin show that fish from the lakes Baikal, Arakhlei and Gusinoe belong to the same nominative subspecies, Leocottus kesslerii kesslerii.

Major Histocompatibility Complex Class II Genes Allele Diversity in Landlocked Seals.

The allelic diversity of exon 2 (DQB gene) and exon 3 (DRB gene) of major histocompatibility complex class II was studied for the first time in two species of the landlocked pinnipeds, Baikal (N = 79) and Caspian (N = 32) seals, and these were in compared with the widespread Arctic species, the ringed seal (N = 13). The analysis of the second exon comprising the antigen-binding region revealed high allelic diversity in all three species but the pattern of the diversity was the most specific for the Baikal seal. This species differs from the other two by the smallest number of alleles in the population, yet they have the largest number of alleles per individual and by the maximum similarity of individual genotypes. Presumably, this specificity is a consequence of the spatial and temporal homogeneity of the Lake Baikal environment. Analysis of the third exon encoding the conserved β2-domain showed that the Baikal seal differs by the greatest number of amino acid sequences per individual, while the Caspian seal has the lowest number of variants. A single variant of the β2-domain, the same as in the ringed seal, predominates in the Caspian seal, whereas in the Baikal seal the two other variants predominate. At the same time, three species-specific amino acid sequences were observed among minor variants in the Caspian seal, while only one was found in the Baikal seal. This fact may suggest a longer period of independent evolution in the Caspian seal compared to the Baikal seal.

New data on the stomatocysts of Spiniferomonas septispina Nicholls (Chrysophyceae, Chromulinales)

Morphotypes of stomatocysts in the Chrysophyceae class can serve as an additional criterion for determining species' taxonomic affiliations. This study provides a detailed description of the stomatocyst morphotype of Spiniferomonas septispina, a species with controversial taxonomic status owing to its structural similarity with Chrysosphaerella annulata. Analysis of the known morphotypes of Spiniferomonas stomatocysts reveals common features, including the presence of a collar or collar complex and an annulus. The stomatocyst morphotype of S. septispina exhibits ornamentation and a widely flared conical collar typical of Spiniferomonas species, distinguishing it from Chrysosphaerella. Based on these findings, we conclude that S. septispina should be classified under the genus Spiniferomonas. Additionally, the formation of S. septispina stomatocysts occurs in October in Lake Baikal at water temperatures ranging from 8.8 ℃ to 9.6 ℃.

The Ability of Gastropods of Lake Baikal to the Feeding and Excretion of Microplastic Particles with Different Morphological Structures

Studies of the pollution of Lake Baikal with microplastic particles have been started quite recently. Almost all research is focused on the assessment of surface water pollution, while the impact of microplastics on Baikal organisms remains unexplored. We conducted a laboratory experiment involving three species of gastropod mollusks, the Palearctic Lymnaea stagnalis (L., 1758) and Radix auricularia (L., 1758), as well as the Baikal endemic Benedictia baicalensis (Gerstfeldt, 1859). Two types of microplastics were used in the experiment: fragments of polystyrene and polyester fibers, prepared independently in the laboratory. These plastic particles, along with the food mixture, were placed in aquariums with mollusks. In total, as a result of the experiment, 386 preparations with mollusk excrement were obtained, of which 144 preparations were for the Radix auricularia species, 176 for the Lymnaea stagnalis species, and 67 for the Benedictia baicalensis species, the experiment with the latter species was carried out only with microplastic fragments. All preparations were analyzed according to the degree of fluorescence. The data were statistically processed using Spearman’s rank correlation coefficient. The data obtained allowed us to conclude that gastropods of these species are able to absorb microplastic particles and remove them from the body. However, the rate of removal of microplastic particles from the body of a mollusk is species-specific, and also directly depends on the morphological structure of microplastic particles.

Планово-высотная параметризация типов рельефа для диагностики опасных гравитационных процессов

The authors present the results of a comprehensive geomorphological analysis of the mountain relief types in the middle part of the Verkhnyaya Angara basin (lake Baikal region) for geoinformation diagnostics of dangerous gravitational processes. The relevance of the study is due to the increasing importance of the Baikal-Amur Mainline; the novelty lies in the fact that a high-precision plane-and-height assessment of the Baikal basin northern part’s hard-to-reach areas. The physical and geographical characteristics of the studied territory are given, tectonic and geological features of the relief formation are indicated. For the metric assessment and subsequent mapping of the terrain in the Arc GIS software environment, a digital model of the studied territory and raster coverings of morphometric parameters of slope and exposure were created based on isolines and elevation marks of the topographic base scale 1:100000. In the process of analyzing the model and geomorphological decoding of the arch-block mountains, the planned-altitude metric parameters of relief types with their characteristic forms and elements, morphometric properties with determining factors of formation and development of gravitational processes were established. High-mountain erosion-exaration-, denudation-erosion-; medium-mountain erosion-denudation-, denudation-erosion- and low-mountain denudation relief types are distinguished. For geomorphometric analysis and diagnostics of slopes, reference polygons characterizing the types of arch-block mountains relief, possessing certain geophysical properties and features were selected. To visualize each polygon, slope mapping-and-exposure was performed, as well as a satellite image was presented. As a result of the conducted research, a typical set of dangerous gravitational processes was identified for each type of relief, as well as their possible intensity, which can create risks of economic activity in mountainous areas. The results of the study can be used in design work for the modernization of the Baikal-Amur Mainline and the development of new mineral deposit

First record of <i>Canthocamptus (Canthocamptus) microstaphylinus</i> Wolf 1905 (Harpacticoida, Copepoda) from a shallow coastal area of Lake Baikal

Female and male specimens of the Palearctic species, Canthocamptus (Canthocamptus) microstaphylinus Wolf 1905, were found in the coastal zone of Lake Baikal, Siberia. This was the first record of the species in Lake Baikal and the Baikal region. A general description and brief morphological characteristics were made using scanning electron microscopy. The authors compared the principal diagnostic morphological traits of C. (C.) microstaphylinus from Lake Baikal and some water bodies from the European part of Russia (within the Syktyvkar City, Republic of Komi). As a result, specimens from Lake Baikal and the Syktyvkar area were shown to be similar in the structure of their thoracic appendages and caudal rami.

Nomenclature and systematics of two Cocconeis species (Bacillariophyta) from Lake Baikal: Cocconeisbaicalensis and Cocconeisskvortzowii.

The study provides nomenclatural history, morphological characteristics and taxonomy of Cocconeisbaicalensis and C.skvortzowii described by B.V. Skvortzov from Lake Baikal. The lecto- and epitypification of the names are made, based on the K.I. Meyer and A.P. Skabichevsky materials, ensuring compliance with current nomenclatural standards. The morphological traits of these species were thoroughly examined using light microscopy (LM) nd scanning electron microscopy (SEM), leading to refined diagnoses and the clarification of previously confused synonymy.

Redescription of Chrysosphaerella baikalensis (Chrysophyceae, Chromulinales) with new data on the ultrastructure of its stomatocysts

An amended description of the ultrastructure of plate and spine scales is provided, along with the first description of the stomatocyst Chrysosphaerella baikalensis from Lake Baikal. C. baikalensis exhibits four types of plate scales: small and large elliptical, large rounded, and large subcircular scales. The spines can grow up to 47 μm in length. The stomatocysts of C. baikalensis are spherical or slightly oblate, with a small, regular pore surrounded by a flat pseudoanulus, lacking a collar. Based on their surface ornamentation, two forms of stomatocysts are distinguished, Forma A covered with densely arranged short needle-like outgrowths and Forma B having a smooth to psilate surface. We associate the first form with the immature stage. In this article, we report the growth of C. baikalensis in Lake Baikal during June, in the open water period, at a water temperature of 3.9–4.5 °C. During this period, whole cells and stomatocysts covered with plate scales were observed. Individual spines and plate scales were found at temperatures up to 11.5 ℃.

Summer daily dynamics of the vertical structure of atmospheric aerosol over Baikal coastal area from ground-based lidar measurements

ABSTRACT The spatial structure of atmospheric aerosol over Baikal in summer is studied on a regular basis with the use of ground-based LOSA-M2 lidar measurements at the Boyarsky scientific station of the Institute of Physical Material Science, Siberian Branch, Russian Academy of Sciences (51.83°N, 106.06°E, 456 m a.s.l.), Republic of Buryatia, Russia. The lake is located in a basin surrounded by mountain ranges on all side; its water volume is large. The lidar data are analysed along with the regional meteorological situation and meteorological parameters of the atmosphere. The daily dynamics of aerosol distribution over the atmospheric is examined for the period from 2015 to 2023 accounting the effect of different air masses in the region. Three main typical air circulation types are identified for the coastal zone of southern Baikal in summer, which determine the atmospheric aerosol generation and transport. The first and most common type relates to breeze circulation, where the main changes in the spatial structure of aerosol occur in the 2–3-km layer and are determined by changes in the transport direction within a breeze cell during the day. The main feature of this type is a decrease in the altitude of an air layer which contains most of aerosol in the lower atmosphere up to 1 km. The second type refers to southwestern transport under the presence of an anticyclone over the region. The maximal altitude of the aerosol layers attains 7 km in this case. The most complex and dynamic changes in the daily spatial structure of atmospheric aerosol occurred under transport of cyclones and associated atmospheric fronts over Lake Baikal. Under this third type, the altitude of the aerosol layers decreases throughout the day within the altitude range from the surface to 3–4 km.