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External view of Dolichospermum lemmermannii from the coastal zone of Bol'shye Koty Bay. Scale bars: А-0.30 mm, В-С-0.16 mm, D-E-65.4 μm.
Source publication
Mass development of the cyanobacteria Dolichospermum (D. lemmermannii as the dominant species) was reported in the coastal zone of Bol shye Koty Bay (western coast of the southern basin), towards the end of July to the beginning of August in 2019. Blooms were observed as 1 1.5-m wide bands adjoining the shoreline and stretched uninterrupted over 2...
Context in source publication
Context 1
... analysis of the "blooming" organisms revealed massive abundance of Dolichospermum cyanobacteria during collection, with a dominance over 98% of the total abundance of D. lemmermannii (Fig. 5). The concentration of Dolichospermum along the shore of the bay varied from 7.2-71.9 thousand cell mL -1 and biomass 0.73-7.20 g m -3 . Maximal concentration was recorded at the site opposite the canteen of the University Biological station, with a minimum at Site No. 3 at the northern end of the bay (Fig. 1). The maximal abundance and ...
Citations
... Other strategies, which contribute to the increasing of the abundance and a subsequent dominance in shallow water bodies, is the ability to form akinetes that can survive unfavourable environmental conditions. This cyanobacterium has successfully adapted to the severe conditions of Lake Baikal and dominated the plankton during summer (Popovskaya, 2000;Bondarenko et al., 2021). ...
The status of Lake Baikal as a UNESCO World Heritage Site, due to its unique ecology and value as a global aquatic resource have resulted in strict environmental regulations to protect the watershed and biota it supports. Despite this, the ecosystem of the lake is being exposed to negative anthropogenic impact and deteriorating water quality. In this article, we describe the bioecological state of Mukhor Bay − the warmest bay of Lake Baikal and one which is actively visited by tourists. We try to highlight the environmental problems of Baikal and aim to change attitudes towards water resources in this unique ecosystem. We present data on the taxonomic, genetic, and biochemical characteristics of cyanobacteria blooms that develop in the plankton of the bay. Further, we establishing their risk to human health and provide information for the environmental state management. Toxic blooms of Dolichospermum lemmermannii (cyanobacteria) were detected in the phytoplankton of Mukhor Bay. The nutrients content and chlorophyll concentration was low and corresponded to the oligo-mesotrophic status. Microcystins were detected in the dried phytoplankton biomass and the water, coastal samples contained a higher amount of this toxin. We hypothesize that one of the factors contributing to toxic cyanobacteria growth in the Mukhor Bay is the nutrient loadings due to surface and groundwater runoff from surrounding area.
... Tissue necroses in damaged animals were accompanied with a rapid development of cyanobacteria. Some of these bacteria, including those revealed in Lake Baikal, produce toxins (Belykh et al., 2016Bondarenko et al., 2021). According to the results obtained by Belykh et al. (2019), the spreading of cyanobacteria in the littoral zone of Lake Baikal should be considered one of the most important negative environmental changes observed in recent years. ...
... Cyanotoxins can be produced by such freshwater genera as Microcystis, Dolichospermum (formerly Anabaena), Planktothrix, Raphidiopsis, and Aphanizomenon (Sukharevich and Polyak, 2020). The production of secondary toxic metabolites by Dolichospermum species poses a threat to the world's significant freshwater ecosystems, such as Lake Baikal (Bondarenko et al., 2021), Lake Tanganyika (Cocquyt et al., 2021) and Laurentian Great Lakes (Sterner et al., 2020). The reported toxins produced by species of the genus Dolichospermum can be categorized by chemical structure into three different groups: cyclic peptides (microcystin), alkaloids (anatoxin-а, guanitoxin (formerly anatoxin-a(S)), saxitoxin, and cylindrospermopsin), and lipopolysaccharide (Li et al., 2016;Fiore et al., 2020). ...
This work studies the composition and abundances of phytoplankton and zooplankton and their relationships during cyanobacteria bloom (mainly Dolichospermum lemmermannii) in two subarctic oligotrophic lakes, a clear deep lake (Krivoe) and a brown shallow lake (Krugloe). Cyanobacteria bloom (D. lemmermannii) was observed four times during 7–10 days in both lakes: late July, late August, September 2019, and late September 2020. The toxicity of cyanobacteria was determined by the presence of cyanotoxins in water and plankton biomass. Microcystins (mostly LR, RR, and other structure variants) were found in every case of visible blooms (July–September of 2019–2020) in the shallow lake and only once in the deep lake. Despite the nutritious food items (cryptomonads), the presence and dominance of colony-forming microalgae (Botryococcus brauni) and filamentous cyanobacteria in both lakes consisted of a low-efficient food base for grazers. A high abundance of toxic microcystins in the shallow lake with dystrophic features led to the specific composition of zooplankton with the prevalence of the selective grazers, copepod Eudiaptomus graciloides, and cladoceran Ceriodaphnia pulchella adapted to cyanotoxins. In a clear deep lake, where toxic variants of microcystins were low or not detected during the cyanobacteria bloom, the omnivorous rotifer Asplanchna priodonta and small grazer Bosmina longirostris reached high abundance. This study confirms close relationships between cyanobacteria and zooplankton communities.
... In Lake Superior, the near-shore and offshore zones experienced blooms of non-toxic Dolichospermum lemmermannii in summer [14,15]. Toxin-producing benthic and planktonic cyanobacteria develop in bays and coastal zones of Lake Baikal [16][17][18][19][20]. ...
... Excessive growth of Dolichospermum cyanobacteria (D. lemmermannii as the dominant species) was first reported in the littoral zone on the western shore of the southern basin at the end of July and the beginning of August in 2019. The abundance of cyanobacteria in blooming spots varied within 7.2-72 million cells L −1 , with 0.73-7.20 g m −3 of biomass attained [16]. ...
For the first time, microcystin-producing cyanobacteria have been detected in Khubsugul, which is ancient, pristine and one of the world’s largest lakes. The microcystin synthetase genes belonged to the genera Nostoc, Microcystis and possibly Snowella spp. No microcystins were found in the water of the lake. Using the HPLC-HRMS/TOF, five microcystin congeners were identified in biofilms from stony substrates sampled in the coastal zone. The concentration of microcystins in biofilms was low: 41.95 µg g−1 d. wt. by ELISA and 55.8 µg g−1 d. wt. using HPLC. The taxonomic composition of planktonic and benthic cyanobacterial communities was determined by means of microscopy and high-throughput sequencing of 16S rDNA amplicons. Nostocales cyanobacteria dominated benthos of Lake Khubsugul and Synechococcales—plankton. The abundance of cyanobacteria was low both in plankton and benthos; there was no mass development of cyanobacteria. Hydrochemical and microbiological analyses showed that the water in the lake was clean; the number of faecal microorganisms was significantly below the acceptable guideline values. Hydrochemical and hydrophysical parameters, and the concentration of chlorophyll a, were low and within the range of values recorded in the 1970s to 1990s, and corresponded to the oligotrophic state of the lake. There were no signs of anthropogenic eutrophication of the lake and no conditions for the cyanobacterial blooms.
... Much of Lake Baikal's shoreline lacks human development, and Baikal's watershed is largely roadless and unpopulated (Moore et al. 2009). Despite low levels of development, uncharacteristic filamentous algal blooms have been occurring throughout the lake since 2010 (Kravtsova et al. 2014;Timoshkin et al. 2016) including cyanobacterial blooms in 2019 (Bondarenko et al. 2021). While increased Ulothrix spp. ...
... Pelagic sites were located 2-5 km offshore from each of the developed sites in water depths of 900-1300 m ( Fig. 1; Supporting Information Table S1). As previous investigations of nearshore algal communities near our sampled locations observed increased filamentous algae (Timoshkin et al. 2016 and cyanobacteria (Bondarenko et al. 2021) in mid-to-late summer, the timing of our sampling was intended to coincide with the annual peaks of tourism and summertime community succession, such that gradients of human disturbance and biological response would likely be most apparent relative to environmental noise. All littoral sites were sampled at approximately the same depth ($1.25 m) at a distance of 8.90-20.75 ...
Sewage released from lakeside development can reshape ecological communities. Nearshore periphyton can rapidly assimilate sewage‐associated nutrients, leading to increases of filamentous algal abundance, thus altering both food abundance and quality for grazers. In Lake Baikal, a large, ultra‐oligotrophic, remote lake in Siberia, filamentous algal abundance has increased near lakeside developments, and localized sewage input is the suspected cause. These shifts are of particular interest in Lake Baikal, where endemic littoral biodiversity is high, lakeside settlements are mostly small, tourism is relatively high (~1.2 million visitors annually), and settlements are separated by large tracts of undisturbed shoreline, enabling investigation of heterogeneity and gradients of disturbance. We surveyed sites along 40 km of Baikal's southwestern shore for sewage indicators—pharmaceuticals and personal care products (PPCPs) and microplastics—as well as periphyton and macroinvertebrate abundance and indicators of food web structure (stable isotopes and fatty acids). Summed PPCP concentrations were spatially related to lakeside development. As predicted, lakeside development was associated with more filamentous algae and lower abundance of sewage‐sensitive mollusks. Periphyton and macroinvertebrate stable isotopes and essential fatty acids suggested that food web structure otherwise remained similar across sites; yet, the invariance of amphipod fatty acid composition, relative to periphyton, suggested that grazers adjust behavior or metabolism to compensate for different periphyton assemblages. Our results demonstrate that even low levels of human disturbance can result in spatial heterogeneity of nearshore ecological responses, with potential for changing trophic interactions that propagate through the food web.
... In other words, it acts as a 'reservoir' of taxa potentially able to colonize Lake Baikal. The lake is now facing drastic changes in its environment, including to the structures of animal and plant communities (e.g., [20][21][22][23][24] and references therein), and suffers from the everincreasing impacts of human activity, which creates conditions favourable for alien animals of Palearctic origin and facilitates their colonization of Lake Baikal. ...
This article aims to reconstruct the invasion of the ear-shaped pond snail, Radix auricularia (Linnaeus, 1758), to Lake Baikal, East Siberia. This species is widely distributed in the Palaearctic and Northern America, and since the early 20th century has formed abundant and sustained populations in Lake Baikal. The data provided on the morphological and genetic variability of R. auric-ularia help to better describe and delineate the species. With an integrative approach involving morphological and molecular data, we improved the knowledge of the intraspecific variability of R. auricularia in the most important characteristics used for its determination. Molecular sequences of nuclear spacer fragment ITS-2 and mitochondrial gene fragment cyt-b were obtained from 32 individuals of Radix (including seven outgroup Radix species) collected from various parts of Lake Baikal and adjacent waterbodies and compared with sequences of 32 individuals of R. auricularia from different regions of the Palaearctic as well as with individuals determinated as R. intercisa from Lake Baikal, R. iturupica from the Kurile Islands, R. ussuriensis from the Khabarovsk region, R. narzykulovi from Tajikistan, and R. schubinae from the Amur region. Molecular genetic analyses revealed that all specimens collected from Lake Baikal belong to R. auricularia. There are no genetically distinct groups of snails that would correspond to two morphospecies previously recorded in Lake Baikal (e.g., R. auricularia s. str. and R. intercisa). Variability of the characteristics that are commonly used for species identification (shell morphology, mantle pigmentation, shape and position of the bursa copulatrix, length and position of the bursa duct, length ratio of preputium to penial sheath) were found in individuals analysed with molecular genetics to be broader than recognised in the current literature. Some shells of R. auricularia collected from Lake Baikal resemble shells of another lymnaeid species, R. balthica, and without molecular assessment can be confused with the latter. Geometric morphometric analysis of more than 250 shells revealed no observed hiatus between Baikalian and non-Baikalian R. auricularia. The probable stages and pathways of R. auricularia invasion to Lake Baikal's ecosystem are outlined and discussed. Factors such as global climate warming and human activity stimulated and facilitated the ongoing dispersal of ear pond snails within Lake Baikal. Citation: Schniebs, K.; Sitnikova,T.Y.;Vinarski, M.V.; Müller, A.; Khanaev, I.V.; Hundsdoerfer, A.K. Morphological and Genetic Variability in Radix auricularia
... In recent years, precipitation in the Baikal region has shifted to late summer-autumn, precisely at the time when nanoplanktonic mixotrophic dinophytes are abundant. The effect of rainfall on the local mass development of cyanoprokaryotes in late summer is considered in detail in (Bondarenko et al., 2021). It turned out that the content of phosphates, nitrates, and ammonium ions in the Baikal water after rains increases 3-30 times compared with the long-term average data. ...
... Nearshore change is particularly important to understand in Lake Baikal, since the majority of the lake's biodiversity and endemic species occur in the littoral zone (Kozhova and Izmest'eva 1998). While Lake Baikal's pelagic zone is generally ultra-oligotrophic (Yoshida et al. 2003;O'Donnell et al. 2017), littoral areas abutting lakeside settlements have recently shown distinct signs of eutrophication, such as increased filamentous green algae abundance (Timoshkin et al. 2016;Volkova et al. 2018) as well as cyanobacteria (Bondarenko et al. 2021). ...
Sewage released from lakeside development can introduce nutrients and micropollutants that can restructure aquatic ecosystems. Lake Baikal, the world's most ancient, biodiverse, and voluminous freshwater lake, has been experiencing localized sewage pollution from lakeside settlements. Nearby increasing filamentous algal abundance suggests benthic communities are responding to localized pollution. We surveyed 40‐km of Lake Baikal's southwestern shoreline from 19 to 23 August 2015 for sewage indicators, including pharmaceuticals, personal care products, and microplastics, with colocated periphyton, macroinvertebrate, stable isotope, and fatty acid samplings. The data are structured in a tidy format (a tabular arrangement familiar to limnologists) to encourage reuse. Unique identifiers corresponding to sampling locations are retained throughout all data files to facilitate interoperability among the dataset's 150+ variables. For Lake Baikal studies, these data can support continued monitoring and research efforts. For global studies of lakes, these data can help characterize sewage prevalence and ecological consequences of anthropogenic disturbance across spatial scales.
... Therefore, the transport of gaseous sulfur and nitrogen oxides to Lake Baikal from the large coal-fired thermal power plants of the region can affect (through precipitation and dry deposition) the productivity of the surface layers in the lake. Recent field experiments have revealed that rainfall and dry depositions significantly influences the dynamics of the abundance of some algal species in aquatic ecosystems in generally [13] and in the lake Baikal particular [14][15][16]. ...
This paper analyzes the results of the automatic (in situ) recording of the regional transport of pollutants from the large regional coal-fired thermal power plants in the atmospheric boundary layer above the southern basin of Lake Baikal. Due to high stacks (about 200 m), emissions from large thermal power plants rise to the altitudes of several hundreds of meters and spread over long distances from their source by tens and hundreds of kilometers. The continuous automatic monitoring of the atmosphere in the southern basin of Lake Baikal on top of the coastal hill (200 m above the lake) revealed the transport of a large number of sulfur oxides and nitrogen oxides in the form of high-altitude plumes from thermal power plants of the large cities located 70 to 100 km to the northwest of the lake (Irkutsk and Angarsk). The consequence of such transport is the increased acidity of precipitation in the southern basin of Lake Baikal and the additional influx of biogenic nitrogen compounds to the lake ecosystem. The spatial scale and possible risks of such regional transport of air pollution for the lake ecosystem require further closer study.
