SCIENTIFIC INVESTIGATIONS
Since 2019, an independent scientific expedition of the environmental monitoring of Lake Baikal has been taking place in the Baikal region.
The Baikal natural territory is one of the most significant ecological systems in Russia and the world. Its most acute issue is ensuring sustainable development of the territory, including the preservation of the integrity of natural landscapes and ecosystems.
In 2021, scientists from seven leading scientific and academic institutions took part in the expedition. They were members of the following institutions: Lomonosov Moscow State University (Moscow), Severtsov Institute of Ecological Evolution Problems of the Russian Academy of Sciences (Moscow), Siberian Federal University (Krasnoyarsk), Irkutsk State University (Irkutsk), Moscow Institute of Physics and Technology (Moscow), the Institute of Limnology of the Russian Academy of Sciences (St. Petersburg), Trofimuk Institute of Petroleum Geology and Geophysics of Siberian Branch Russian Academy of Sciences (Novosibirsk).
In 2021, scientists from seven leading scientific and academic institutions took part in the expedition. They were members of the following institutions: Lomonosov Moscow State University (Moscow), Severtsov Institute of Ecological Evolution Problems of the Russian Academy of Sciences (Moscow), Siberian Federal University (Krasnoyarsk), Irkutsk State University (Irkutsk), Moscow Institute of Physics and Technology (Moscow), the Institute of Limnology of the Russian Academy of Sciences (St. Petersburg), Trofimuk Institute of Petroleum Geology and Geophysics of Siberian Branch Russian Academy of Sciences (Novosibirsk).
Mikhail Kolobov, Head of the expedition: "It is necessary to understand the real environmental situation in order to assess environmental risks, make forecasts and make further decisions affecting the fate of Lake Baikal. Identifying and studying the main threats to Lake Baikal ecosystems is the goal of our research. Research areas include assessing heavy metals and nutrients as well as plastic and microplastic pollution. The study of changes in the lake’s ecosystem in response to anthropogenic impacts is also one of the main objectives"
The scientists focused on the areas most exposed to anthropogenic load, as well as on the Selenga River, the main tributary of Lake Baikal.
Some of the effects of anthropogenic pressure on the lake’s ecosystem can be observed with the naked eye. These include "green tides" (massive blooming of planktonic algae), and the reproduction of the filamentous algae spirogyra. The data obtained during the expedition helps shed light on the causes of the main environmental problems of the lake.
Some of the effects of anthropogenic pressure on the lake’s ecosystem can be observed with the naked eye. These include "green tides" (massive blooming of planktonic algae), and the reproduction of the filamentous algae spirogyra. The data obtained during the expedition helps shed light on the causes of the main environmental problems of the lake.
Major current threats to Lake Baikal are:
● increased concentrations of phosphorus-bearing compounds and heavy metals in Selenga River waters;
● hidden influx of nitrogenous substances with groundwater into the Baikal watershed near settlements;
● plastic and microplastic pollution in the lake;
● input of unidentified potentially hazardous organic compounds from the watershed through surface and groundwater runoff.
● increased concentrations of phosphorus-bearing compounds and heavy metals in Selenga River waters;
● hidden influx of nitrogenous substances with groundwater into the Baikal watershed near settlements;
● plastic and microplastic pollution in the lake;
● input of unidentified potentially hazardous organic compounds from the watershed through surface and groundwater runoff.
Plastic and microplastic pollution of Lake Baikal
Once in the environment, plastic does not decompose in a direct sense. It is very stable and gradually decomposes into smaller and smaller pieces, forming microplastics and maintaining its molecular structure. Microplastics are fragments of any type of plastic, ranging in size from 5 millimeters to one micrometer. They are formed by bags, bottles, any other plastic packaging, car tires, as well as microfibers washed down the drain after washing synthetic clothes. As part of environmental monitoring expeditions, microplastic pollution of Lake Baikal coastal waters was evaluated. Samples were gathered from 36 sample locations.
A large patch of microplastics, similar to the Great Pacific garbage patch, has formed in the south of Olkhon, Bolshoye Goloustnoye settlement and the Selenga Delta. Microplastics can be 10 times more concentrated there than in other places. Microplastics are divided into fibers (our clothing) and pieces (household packaging). Fibers are most abundant in the north and pieces in the south of the lake. This is probably due to their hydrodynamics.
Fibers predominated at all sampling locations, followed by fragments. The highest number of microplastic fibers was at the cutoff near Slyudyanka settlement, with an average of 310 particles/m3. Now there is a patch of microplastic sized of two A4 sheets for every square km of the lake’s surface.
In 2020, the scientists of the Institute of Biology at the Irkutsk State University came to a conclusion about the prevalence of fibers among the microplastics in Lake Baikal. The findings may be a direct outcome of both drawbacks in the solid household waste management (which includes plastics) and poor performance or lack of wastewater treatment facilities (since microplastic fibers can enter water bodies mainly through wastewater).
Plastic pollution of shores and water of Lake Baikal is also caused by wild tourism. The number of tourists coming to Lake Baikal has increased due to the change in tourist routes caused by the COVID-19 pandemic. The lack of sufficient tourist infrastructure with equipped and regularly maintained waste collection sites has contributed to the increase of coastal pollution during the 2020−2021 tourist seasons. Sooner or later (if not removed by volunteers), single-use plastics left by tourists on the shores of the lake will be washed away by rain or blown into the lake by the wind. Once submerged, plastic remains there. Over time, waves, rocks, and marine microorganisms turn plastic into microplastics. This process accumulates plastic in the lake. Preventing new plastic from entering Lake Baikal’s waters is the only way to combat this.
Plastic pollution of shores and water of Lake Baikal is also caused by wild tourism. The number of tourists coming to Lake Baikal has increased due to the change in tourist routes caused by the COVID-19 pandemic. The lack of sufficient tourist infrastructure with equipped and regularly maintained waste collection sites has contributed to the increase of coastal pollution during the 2020−2021 tourist seasons. Sooner or later (if not removed by volunteers), single-use plastics left by tourists on the shores of the lake will be washed away by rain or blown into the lake by the wind. Once submerged, plastic remains there. Over time, waves, rocks, and marine microorganisms turn plastic into microplastics. This process accumulates plastic in the lake. Preventing new plastic from entering Lake Baikal’s waters is the only way to combat this.
So far, research was conducted in ecology, geophysics, molecular biology and genetics, hydrochemistry and hydrobiology. Analyses were performed both at sampling sites and in the most modern laboratories in Russia. The aim of this comprehensive research is to obtain data on the real environmental situation in Lake Baikal and the Selenga and Angara rivers, to identify and classify existing threats to the ecological well-being of the lake, and to evaluate their potential sources.
Pollutant influx with Selenga River runoff
The Selenga River is the main tributary of Lake Baikal. A large number of industrial, agricultural, processing and mining enterprises, settlements, and cities are concentrated in its transboundary basin. Currently, the regions located in the Selenga River basin are undergoing active development, and as a result, water consumption and wastewater volumes are increasing. Therefore, the Selenga River is considered a major threat to the sustainability of Lake Baikal's ecosystem, carrying up to 50% of the river flow and more than 50% of the chemical flow into the lake.
During the five-year research, it was found that phosphorus compounds have high concentrations even before Ulan-Ude, indicating that the main amount of phosphorus compounds most likely comes from the Mongolian territory, where 2/3 of the Selenga River watershed is located.
Another problem is the influx of heavy metals with the Selenga water in significant concentrations, exceeding the MAC. These metals are copper, zinc, iron, cadmium and manganese. They are toxic to the flora and fauna of the Selenga Delta in varying degrees. As a result, the delta can no longer function as a biofilter to protect Lake Baikal. Due to the influx of high concentrations of pollutants from the Selenga flow, populations of the Baikal sponge and the gammarus crustacean are diminishing. The absence of the Baikal sponges in Listvyanka has been established by our colleagues from the Limnological Institute a long time ago. By 2024, the large branching sponges, which were present in relatively large numbers in 2019−2020, have disappeared in Bolshoi Goloustny. This reflects the process of ecosystem transformation.
Nitrogen influx into Lake Baikal coastal waters near settlements
The results of the research conducted showed that in all water samples collected in wells with aquifer depths from 5 to 100 meters, the concentrations of nutrients were significantly increased. In some water samples (Gremyachinsk, Maksimikha settlements), phosphonates and non-ionic surfactants, which are components of detergents and markers of human household activities, were present in addition to substances that primarily mark fecal wastewater (ammonium, nitrites, nitrates, phosphates). Sewage accumulates in soils beneath settlements up to 100 meters deep — almost to the bedrock.
Groundwater temperature is very low throughout the year, ranging from 0.1−3 to 4−7 °C. No significant processes of biological cleaning of groundwater from organic compounds (including nitrification and denitrification) can be observed.
Due to the lack of treatment facilities in the settlements, the products of human activity accumulate in the soil and are gradually washed into Lake Baikal with the groundwater at a depth of 3−5 meters.
The locals also collects drinking water from their own wells in the areas where domestic sewage accumulates in the ground. Significant exceedance of background concentrations of sewage marker substances (nitrogen compounds) was found in water samples taken from domestic wells in the settlements of Maksimikha, Gremyachinsk, Gryachinsk, Vydrino, Listvyanka, Khuzhir, Bolshoye Goloustnoye (29 samples in total). In other words, these wells can hardly be called "drinking wells", because they contain poorly treated sewage.