1. Introduction
1.1. Microplastics: A Global Environmental Phenomenon
The sensational discovery by the English scientist A. Parkes in 1862 [1,2,3,4], presented as a new material called “parkesine” [3], created from cellulose nitrate, did not envision the subsequent catastrophic consequences which would become a global environmental problem half a century later [5,6]. Plastic pollution in the environment, which has become one of the most pressing problems of our time, is a negative source of impact on aquatic ecosystems [4,7,8,9,10,11,12]. Plastic is durable and almost non-degradable in nature. Its collection is challenging due to the degradation of large plastic products by sunlight, water and wind [13,14,15,16] as well as the decomposition of plastic garbage, resulting in smaller plastic particles. Depending on the production and time of plastic deposition, degradation and redeposition in the environment, plastic particles can be found in different sizes (macro- or mesoplastic (>5.00 mm) or coarse microplastic (2.00–5.00 mm)), shapes (fragments, films, filaments and fibers, among others) and colors (white, red, black, brown, blue, silver, transparent, etc.) [17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34]. When small plastic particles, and among them microplastics (MPs), are released into aquatic systems, they can cause serious problems for aquatic organisms (ichthyofauna and flora) and further down the food chain, affecting human health through the consumption of contaminated food [35,36,37,38,39].
One of the components of this problem is the pollution of surface waters and the world ocean by MPs. Despite the considerable attention paid to this problem in scientific research, the main attention has long been paid to marine ecosystems [40,41,42,43,44,45,46,47].
In recent years, an increasing number of publications has reduced this research gap [47,48,49,50,51,52]. From these publications, it is known that MP particles can have a complex negative impact on aquatic ecosystems, including mechanisms of physical and chemical impact. Taking this into account, as well as the fact of significant pollution of freshwater ecosystems by MP particles, it is necessary to include MPs in the program of surface water monitoring, including the monitoring of freshwater lakes. Some aspects of the current situation with MPs in the aquatic ecosystems of lakes are described in [47,48,49,50,51,52].
1.2. Microplastics Research in Kazakhstan and Central Asia
Although microplastics were officially recognized as an ecosystem pollutant at the global level in the early 2000s, they are of growing concern in Kazakhstan currently. MPs are practically not studied in Kazakhstan. The prerequisites for the beginning of the present study were a huge amount of plastic garbage found during previous field studies. With scientific investigations analyzing the degree of pollution by plastic of the world ocean, freshwater ecosystems and the environment as a whole [40,41,42,43,44,45,46,47,48,49,50,51,52], we raise for the first time the issues of micro- and macroplastic pollution of the environment in Kazakhstan, with the example of the freshwater Lake Markakol (48°45′ N 85°45′ E). The present study was carried out within the framework of a scientific project under grant funding from the Ministry of Science and Higher Education of the Republic of Kazakhstan (AP14870595) “Monitoring of the state and assessment of the level of pollution by micro- and macroplastics in the aquatic environment of Lake Markakol”.
A literature review demonstrates the relevance of plastic pollution [53,54,55,56,57,58,59,60]. The detection of MPs in water and bottom sediment samples in landlocked countries of Central and East Asia indicates that even less densely populated countries are exposed to MP pollution. It is difficult to understand the severity of MP pollution in these countries because of the limited number of regional MP pollution analyses. Experts claim that among all landlocked countries in Asia, Mongolia has the most studies on MP pollution, while Turkmenistan, Afghanistan, Uzbekistan, Kyrgyzstan, Tajikistan and Kazakhstan have nearly none [61].
Unfortunately, references to studies on plastic in the aquatic environment in Kazakhstan are rather scarce. One of the first references to plastic debris in Kazakhstan was made by Baimukanov M. (2017) in the publication “How to save the Caspian seal (Pusa caspica)”. Here, the author noted the visual detection of plastic debris on the Kazakh shores of the Caspian Sea. In 2021, the same author emphasized the need to study the problem of plastic pollution and its impact on the biodiversity of water bodies in Kazakhstan [62,63]. Interesting results were also obtained by a group of scientists led by N. Salikova, who conducted an ecological assessment of MP pollution of solid domestic waste landfills in the Akmola region located in northern Kazakhstan. Thus, the results obtained during the study should serve as both prerequisite and fundamental data for the forthcoming numerical modeling of MP behavior in soil and water [64]. The results of another study on the tributaries of the Syrdarya River conducted by Uzbek colleagues also aroused interest [65]. Thus, according to these authors, they screened the MP content in the surface water and bottom sediments of the Karadarya and Chirchik rivers, the first-order tributaries of the Syrdarya River in Uzbekistan. The average amount of MPs in the Karadarya and Chirchik rivers was 4.28 ± 0.09 and 0.95 ± 0.36 items per m3, and in the benthic sediments, it reached 244 ± 28.9 and 333 ± 11.5 items per kg of dry soil, respectively. The MP concentrations in the surface water and bottom sediments of the Karadarya River were significantly higher (p value <0.01) than those in the Chirchik River. Microfibers were the most widespread there; the proportion of MP fibers in the water of the Karadarya and Chirchik rivers was 89% and 95%, and in the rivers’ bottom sediments, it was 86% and 84%, respectively [65]. The prevalence of microfibers may indicate the pathway of entry into the rivers through discharges of domestic wastewater treatment facilities. Polymer microparticles in surface water and bottom sediments of the Karadarya and Chirchik rivers were mainly represented by polyethylene terephthalate (PET), which accounts for half of all MPs found in the Karadarya River. Textile-origin microparticles were particularly abundant in the Karadarya River, where viscose and nylon fibers were detected, indicating the leading role of synthetic textiles in this kind of pollution. The above-mentioned data are the first experimental evidence of MP pollution in the tributaries of the Syrdarya River. But the distribution and circulation of MPs in the surface waters of Central Asia require further comprehensive studies [65].
Such analyses have not been carried out in Lake Markakol or its tributaries until now. Due to the lake’s location in the center of a nature protection area, MP pollution was not expected there, like in other strongly protected areas. But plastic garbage was observed by us in the Lake Markakol study area during last year’s field campaigns, especially along tourist paths.
Thus, the purpose of this study is detection of macroplastic and microplastic pollution in the water of both Lake Markakol and the main inflowing rivers as well as the one out-flowing river for the first time, in addition to identification of their spatial distribution.
2. Materials and Methodology
2.1. Lake Markakol: Importance of Microplastics Studies
Lake Markakol is a high mountain lake located in the Markakol National Nature Reserve which is known as a unique nature site. The choice of this lake is justified by its geographical location and its status within the UNESCO World Network of Biosphere Reserves [66]. Lake Markakol belongs to the lakes of intra-mountain depressions and is located 1447 m above sea level, being a a so-called “background water body” in Kazakhstan because it counts as undisturbed and is relatively less vulnerable to anthropogenic pollution [67,68]. Detection of plastic pollution is a unique and important objective even in Central Asia. It demands both more public attention and resonance and the continuation of research and the fight against plastic pollution.
The mountain ridges around Lake Markakol have heights 2000–3000 m above sea level. The catchment area of the lake is 1180 km2, the surface area of the lake is 455 km2, and its volume is 6.5 km3. The lake is 38 km long and 19 km wide with a maximum depth of 27 m, while its average depth is 14.3 m [69,70]. The lake is famous for its unique flora and fauna, including rare and endemic fish species such as lenok and grayling. The lake is surrounded by the Markakol Reserve, which was founded to protect and preserve the local ecosystems. The lake’s water surface and the adjacent forest and mountain areas provide favorable conditions for many species of birds, mammals and plants.
The lake is a flowing lake as it is fed by several large tributaries (Urunkhaika, Topolevka, Tikhushka, Zhirelka, Elovka and Matabai) and 27 small streams feeding the lake with water from the surrounding mountains, while the Kalzhyr River flows out of it [68,69,71].
Lake Markakol’s area is characterized as the coldest region in Kazakhstan, with a minimum temperature of −55 °C and only 162 warm days per year. According to data from the official website of the Republic State Institution “Markakol State Nature Reserve” [69], ice formation on the lake occurs in November–December, and opening and complete clearing of ice occurs by the end of May. According to Kazhydromet’s observations, the average long-term air temperature values for January and July were −22.0 °C and 14.5 °C, respectively. Consequently, the choice of time for the field campaign took into account the climatic features and characteristics of Lake Markakol. This is why the summer period was the most suitable time period for the field work.
The water in the lake is fresh. It is an important source of drinking water and a habitat for various species of flora and fauna.
Despite the fact that Lake Markakol is located in a remote, mountainous area, there are several settlements in the vicinity of the lake, including the village of Markakol and small villages in the surrounding areas, like Urunkhaika and Zharma.
Like many natural objects, Lake Markakol faces the impact of anthropogenic activities such as poaching and eco-tourism. Thus, popular tourist trips among nature lovers and an increasing number of tourists during the summer months have led to increased pressure on the ecosystem of the lake, such as through the dumping of solid household waste and food residue in the surrounding lakes and, of course, abandoned poachers’ fishing nets.
2.2. Sampling
Based on information on the climate of the Markakol Basin [72], field studies were conducted from 3 July to 13 August 2023.
Sampling for the detection of plastic particles of various size groups in water samples was carried out according to literary sources [4,26,72,73,74,75,76,77,78,79,80,81], with the process reflected in the block diagram below (Figure 1).
The main advantage of such nets is the rapid filtration of a large volume of water and the selection of only a concentrated sample [26,81]. They allow representative sampling from a large water surface area, sampling MP particles in the millimeter range [76,77].
For sample collection across the water area, a plankton net was towed along the surface layer at predetermined areas of the lake (Figure 1 and Figure 2) at an average speed of 2.0 knots (1.89–2.43 knots from a PM 550.2 RIB boat) [4,74,79,80,82] with a duration of 15 min on board [4,74,75,79,82,83], making it less susceptible to wave disturbances [78]. The towing time depended on the suspended sediment concentration in the water, as the plankton net was completely clogged in 15 min [4,74,75,79,82,83]. When the net became clogged, such as in the case of algal blooms or large accumulations of floating debris, the towing time could be reduced [79]. The net contents were washed into glass jars for samples and further laboratory processing [76,77,84]. Due to different surface water inflow conditions for the tributaries and the one outflow by the Kalzyr River, the lake was divided into five sampling zones (Figure 2), taking into account the influence of the main tributaries and the assessment of potential pollution sources.
2.3. Water Sample Preparation Process
Laboratory water samples from the field were passed through stainless steel sieves 20 cm in diameter and 5 cm deep, each with mesh sizes of 25 mm, 10 mm, 5.0 mm (ISO 3310-2 2000/50) [85], 1.0 mm and 0.315 mm (GOST R 51568-99 200/50) [86] placed one above the other, and washed thoroughly with distilled water to transfer all solid particles to the sieves [26,76,84]. To determine the presence of plastic types, all sieve mesh sizes were considered.
A further sample analysis process started with drying and ended with visual sorting, which served to sequentially prepare and analyze the water samples for micro- and macroplastic detection [84].
2.4. Process for the Determination of Micro- and Macroplastics in Water
After passing the material through a set of sieves [18,26,87,88,89,90,91]. The solids were transferred to a pre-weighed clean beaker and dried at 90 °C for 24 h in a desiccator [22,84,92,93,94]. After a lapse of time, the mass of the laboratory beaker with dried solids was weighed to obtain the total mass of MPs and natural materials, and 20 mL of iron (II) sulfate catalyst and 20 mL of 30% hydrogen peroxide [95,96] were added to the chemical beaker with the solids. During the removal of organic matter in the prepared solution of iron (II) sulphate, 3 mL of concentrated H2SO4 (pH 4) was added. The mixture was left at room temperature for 5 min and then heated to 75 °C while being stirred by a magnetic stirrer [89,97]. After oxidation, 6 g of sodium chloride [30,79,98] was added for every 20 mL of sample to increase the density of the solution and remove inorganic matter through foam separation, undergoing density separation through flotation using a separator. The solution was transferred to a density separator and left overnight. Then, the precipitate was visually inspected for MP particles, and the residue was passed through a 0.315 mm sieve. The microplastics collected on the sieve were dried and weighed to determine their concentration. The isolated MP particles were visually inspected using a microscope with a 40× magnification [76,84], which allowed the visual identification of plastic particles. The main criteria were luster, brightness and unusual color, which could indicate the presence of plastic, especially if the particles exhibited typical plastic material properties [26,79], as well as elasticity and hardness, which could be determined using tweezers [99]. MP particles larger than 1.0 mm could be visually separated using the following rules [74,79,100,101,102]: (1) absence of a cellular structure and other organic forms, which helps exclude organic materials, (2) uniform coloration and fiber thickness and (3) a clean and uniform color (i.e., uniform color without inclusions or stains). Color is an important parameter in the visual identification of plastic particles in both marine and freshwater environments because it can provide information about the type and condition of the plastic, as well as its history and environmental impacts [26,102,103]. The visual identification of colors was carried out both by eye and by examination under a microscope.
The described steps provide a systematic and comprehensive analysis of samples for the presence of MPs, from the extraction of particulate matter from a sample to its visual and quantitative analysis [84].
3. Results
The initial survey for plastic pollution in Lake Markakol showed the presence of plastic particles of various sizes, among which fragments of fishing line fibers and food wraps were the most common. Plastic microparticles smaller than 1.0–5.0 mm were found both in the lake itself and in its tributaries. This is an unexpected finding for this unique lake and its isolated location.
The concentrations and sizes of the MPs detected in the water of the lake and in the main tributaries had different spatial distribution patterns (Table 1).
In the eastern part of the lake, large amounts of plastic debris were detected in the Urunhaika River, with concentrations up to 56.8 µg/m3 for 1.0–5.0 mm particles and 11.5 µg/m3 for 0.315–1.0 mm particles. The detected litter was mainly of polyethylene origin.
The northeastern part of the lake, where the Tikhushka, Zhirelka and Topolevka rivers flow into the lake, was also characterized by high concentrations of MPs. The MP concentrations were found for the Topolevka River (157.2 µg/m3), Tikhushka River (97.9 µg/m3) and Zhirelka River (67.8 µg/m3). The size of the detected MPs in these rivers varied between 1.0 and 5.0 mm and 0.315 and 1.0 mm in the Tikhushka River (sieve mesh: 1.0–5.0 mm, 67.7 µg/m3 and 0.315–1.0 mm, 30.2 µg/m3), Zhirelka River (sieve mesh: 1.0–5.0 mm, 43.8 µg/m3 and 0.315–1.0 mm, 24.0 µg/m3) and Topolevka River (sieve mesh: 1.0–5.0 mm, 130.9 µg/m3 and 0.315–1.0 mm, 26.2 µg/m3). In the Yelovka River, MPs were found for the 0.315–1.0 mm sieve mesh size (12.6 µg/m3).
The Matabai River flows from the south into the lake, and it had lower MP concentrations compared with the northern tributaries 78.3 µg/m3 (1.0–5.0 mm, 57.4 µg/m3 and 0.315–1.0 mm, 20.9 µg/m3).
The total MP concentrations in the surface layer of the lake were also extremely high, being 316.7 µg/m3 for the 1.0–5.0 mm particles and 520.8 µg/m3 for the 0.315–1.0 mm particles, giving a total water area MP concentration of 837.4 µg/m3. MP particles larger than 5.0 mg/m3 were not found in either the inflowing rivers or the lake water. Non-MP particles were found only in the effluent of the Kalzhyr River (Table 1).
Figure 3 shows high concentrations of MPs in the eastern part of the lake (zone 1) for particles in 1.0–5.0 mm size up to 121.3 µg/m3 and for particles 0.315–1.0 mm in size up to 165.5 µg/m3 in the zone of influence for the Urunhaika, Tikhushka, Topolevka and Zhirelka rivers, resulting a total of 391.2 µg/m3 for the polluted effluents. High values of MPs were also characteristic for zone 2 (200.2 µg/m3), zone 4 (157.3 µg/m3) and zone 5 (151.6 µg/m3), which were also influenced by rivers from the northern slopes (Yelovka River (zone 2 and 3)) and from the southern slopes (Matabai River (zone 4)). The lowest MP pollution level was observed in zone 3 (up to 41.6 µg/m3), corresponding to particle sizes of 1.0–5.0 mm (4.0 µg/m3) and 0.315–1.0 mm (37.6 µg/m3).
The data on plastic components in the aquatic ecosystem of Lake Markakol indicate serious pollution problems in the lake and its tributaries due to MPs. Fragments of fishing line nets, Styrofoam balls, plastic bags, plastic bottles, wrappers, labels, food packaging and other types of plastic waste predominated the detected plastics (Table 2 and Figure 4). These particles, found to be both mesoplastics (large fragments) and microplastics (microscopic particles), were of different sizes and colors (green, black, red, blue, white, and transparent).
The results (Table 1 and Table 2 and Figure 4) indicate a wide variety of plastic pollution in the aquatic ecosystem of Lake Markakol.
4. Discussion
4.1. Discussion of the Lake Markakol MP Analyses
This initial study on plastics, including mesoplastics and microplastics, in the Lake Markakol environment, including the tributary rivers and the only outflow, illustrated both the plastic load of the tributaries and the plastic sink of the lake.
Data on high concentrations of MPs in different areas of Lake Markakol indicate serious pollution problems. For the 0.315–1.0 mm particle size, the highest MP content of the tributaries to the lake was found in the Tishushka River (30.2 µm/m3), decreasing in the order of the Topolevka River, Zhirelka River, Malaiba River, Yelovka River and Urunhaika River (11.5 µm/m3). For the 1.0–5.0 mm particle size, the highest MP content of the tributaries to the lake was found in the Topolovka River (130.9 µm/m3), decreasing in the order of the Tishushka River, Malaiba River, Urunhaika River and Zhirelka River (43.8 µm/m3) (Figure 3). The highest MP contents within the lake zones for the 0.315–1.0 mm particle size were found in zone 1 (165.5 µm/m3), decreasing in the order of zone 4, zone 5, zone 2 and zone 3 (37.6 µm/m3). The corresponding MP contents for the 1.0–5.0 mm particle size for the lake zones were 147.2 µm/m3 in zone 2, followed by zone 1, zone 5, zone 4 and zone 3 (4.0 µm/m3) (Figure 3). High MP concentrations were found in the northern, northeastern and southern zones (Figure 2 and Table 1 and Table 2) of the lake, especially in the confluence areas of the Topolevka, Urunhaika and Matabai rivers, indicating that these areas are active MP pollution hotspots.
The total concentration of macro- and microplastics contributed by the tributaries was 482.1 µg/m3, while the lake water area had a higher concentration of 837.5 µg/m3. These results, together with the non-plastic loaded effluent of the Kazhyr River, indicate that Lake Markakol is a significant MP sink, while the tributaries significantly contribute to the overall pollution pattern.
The indications of possible reasons for the detection of MPs in lake and river areas, such as poaching and unconstructive tourism, emphasize the importance of the anthropogenic influence on the pollution of aquatic systems. Polyamide fiber nets, monofilament and other plastic materials left behind can create significant pollution and harm to ecosystems, including endemic fish species. According to our observations, the majority of the plastic was associated with local pollution sources, as larger fractions were found in the inflowing rivers of the lake. Also, some of the plastic found in the lake water was of polymer origin, typical of monofilament nets used in fishing activities. These findings suggest that much of the plastic in the lake came from local pollutants and unsustainable fishing practices. At the same time, the transfer of plastic particles from places of unorganized collection of household waste could not be ruled out.
Some of the detected MP particles of the ecosystem of the high-mountain Lake Markakol are probably associated with the increasing tourism in this area. According to oral communication from the heads of community administrations of the surrounding communities, the number of tourists visiting Lake Markakol has increased substantially over the last three decades. Despite the remoteness, inaccessibility, low population and harsh natural and climatic conditions, according to reference data of the “Markakol State Nature Reserve” RSE, the growth of tourists to Lake Markakol over the last 5 years increased from 661 to 892 people per season. Another reason for the large number of mesoplastic particles and MP traces found in our investigations might be the close proximity of the settlement to the lake. Inefficient household waste management, insufficient infrastructure for waste collection and recycling and the widespread use of plastic products in everyday life are obvious reasons for the plastic and MP distribution in the study area. The low specific gravity of plastic particles can cause their widespread distribution in aquatic systems, since they can be transported to various zones of lakes, reservoirs or rivers and deposited in bottom sediments and soils [104,105,106] under the influence of water flow and air streams.
The used methods were suitable for the first inventory of MP occurrence in the Lake Markakol study area, including the tributaries and the outflow. But using color alone to identify MPs may not be sufficient, especially in cases where the plastic is obscured by a large amount of biological residue. In such situations, additional analyses, such as by microscopy or chemical methods, are required to accurately identify plastic and minimize errors in the MP analysis process. In some cases, it is suggested to disregard transparent and white and black color particles because they interfere with biological material and other substances which can be misidentified as plastic [76,99]. For reliable and rapid identification of large MP particles, it is advisable to use techniques such as pyrolysis-gas chromatography with mass spectrometry (Pyr-GC/MS), Fourier transform infrared spectroscopy (FTIR, μ-FTIR) or Raman spectroscopy (Raman, μ-Raman).
This may pose a problem with water pollution over large areas. In addition, long-range atmospheric transport of small plastic particles is possible [107,108]. This problem also requires further analyses.
4.2. Comparison with Microplastics Studies of Other Water Bodies
Malygina N. et al. [108] conducted a study which dealt with the MP content in the aquatic environment of mountain lakes in Siberia, particularly in Altai and the West Siberian Plain. The authors focused on six lakes: Talmen, Dzhulukul, Teletskoye, Zludyri, Degtyarka and Kuchuk. These lakes are located in the strictly protected Katunsky and Altai areas. These lakes are not affected by industrial activities. They are located in protected areas without permanent populations, and they contained MP particles, the concentrations of which ranged from 4 to 26 particles per liter of water, mainly from various human activities such as fishing, vehicles and waste disposal, especially by tourists. Even in such remote lakes where human activities are limited, high concentrations of MPs were observed. This emphasizes the need for increased attention to waste management and to careful water use in freshwater environments in order to maintain a basic level of environmental and health safety.
Studies conducted in 2011–2013 by the Limnological Institute of the Siberian Branch of the Russian Academy of Sciences [109] and later by Greenpeace on Lake Baikal [110] revealed significant pollution in the lake from household waste, including plastics. Statistics show that up to 87% of the plastic found on the Lake Baikal coast is single-use plastics. In addition, the concentration of MPs in the lake water and on its shores turned out to be high, according to a study by Moscow State University’s (MSU) specialists [111]. For samples taken from the water surface in the coastal zone of the most populated southeastern coast and in the so-called Small Sea near Olkhon Island, in terms of water surface area, the concentration of particles ranged from 19,000 to 75,000 plastic particles per 1 km2, with an average value of 42,000 particles per 1 km2, which corresponds to a high degree of plastic pollution [111]. Based on chemical composition, the particles were identified to be polyethylene, polypropylene and polystyrene. It is assumed that the MPs detected during this study were decomposition products of various household packaging materials [111].
According to our own long-term observations since 1987 (1988, 2000, 2002, 2003, 2006, 2007, 2009 and 2018) in these case study areas, both in the Altai Mountains (Russian part in West Siberia) and in and around Lake Baikal (East Siberia in Russia), the increasing number of tourists, including unguided and so-called “wild” tourism, is responsible for the huge deposition and distribution of plastic and MPs in these natural lake environments.
Studies conducted by limnologists in the last decade have provided a broader picture of the MP content in lakes around the world and its impact on aquatic ecosystems. About 90 lakes in different regions of Asia, Europe, North and South America and Antarctica were analyzed regarding their plastic pollution [49,112,113,114,115]. Chinese scientists processed data from 66 lakes, emphasizing the study of urban influences on MP accumulation in water and sediments [115,116]. Limnologists also found that large lakes have significantly lower MP contents in their mud compared with smaller water bodies. For example, in Lake Victoria, the concentration of MP particles was 6.5 granules per kilogram, while in a small pond in London, this value reached 540 particles per kilogram [114,116]. In the sediments of large lakes, MPs are mainly represented by coarse debris and particles ranging in size from 1 to 5 mm. Light MP fibers easily migrate through the water column, moving upward, downward and horizontally. This allows them to spread over long distances and affect different areas of water bodies [117]. One study [118] was conducted to assess MP pollution in a large, remote mountain lake, namely Hovsgol Lake, located in the mountains of northern Mongolia, which despite its remoteness, protected status and low population density was also prone to MP pollution.
Thus, in the world practice, pollution of water bodies by MPs has no restrictions, whether it is the world ocean, seas, rivers, large or small lakes or regions which are flat or mountainous, densely populated or low in population density or located in specially protected conservation areas or in urbanized areas.
5. Conclusions
This study was the first assessment of micro- and macroplastic pollution in the water area of Lake Markakol and its main tributaries in northeastern Kazakhstan. Lake Markakol is located within the Markakol Reserve, which is included in the UNESCO World Network of Biosphere Reserves, and it was previously considered to be unaffected by anthropogenic impacts.
However, this study showed that Lake Markakol has also been affected by plastic pollution. The main sources of pollution here were recreational and poaching fishing, a lack of organized collection of solid waste as well as a low level of environmental awareness for both tourists and the local population. We identified the main inflowing rivers as sources of plastic and MP inputs into the lake, but non-point plastic and MP inputs were also proven. The comparison of the MP concentrations in the tributary rivers, in just the effluent river and within the lake shows clearly that Lake Markakol is functioning as a MP sink. MP measurements in different zones of the lake showed higher MP concentrations under the influence of the northern lake coast and the Topolevka, Tikhushka, Zhirelka and Yelovka tributary rivers. The corresponding MP concentrations along the south coast of the lake under the influence of the Matabai River tributary and the out-flowing Kazhyr River were quite lower. This MP content pattern was probably caused by both local inefficient waste management of the rural villages and the increasing number of tourists. Although the total number of plastic-wasting tourists was low in the Lake Markakol study area in comparison with other mountain lakes, despite the remoteness, inaccessibility, low population and harsh natural and climatic conditions, the number of tourists has increased. According to the reference data of the “Markakol State Nature Reserve” RSE, the growth of tourists at Markakol Lake for the last 5 years has increased from 661 to 892 people per season. Therefore, continued monitoring of plastics in aquatic ecosystems is an important step in understanding the extent of the problems and developing effective pollution management strategies.
For analyzing of the MP status of Lake Markakol the first time, the investigation approach, analyzing the MP pollution in both the inflowing rivers and in different lake zones, was suitable. However, to extend the knowledge about the input, storage, including transformation and output situation of MPs, repeated inspections are necessary, both during the same season and during other seasons. Determining the exact sources of origin of plastics will be the subject of future research, including use of the FTIR and Raman spectroscopy methods, which will allow us to more accurately determine the origins of new pollutants.
These observations emphasize the importance of the interaction of the geographical, hydrological and climatic features of a study area for MP analyses in aquatic systems. Additional research may help to understand the processes occurring in Lake Markakol and its catchment area better as well as provide recommendations for managing and reducing plastic pollution in the area.
The results of this study can be used for the development of more large-scale projects on MP problems in lakes. The knowledge about the presence of MPs in water bodies in the Republic of Kazakhstan will improve the understanding of the dimension of MP pollution problems and their impact on the aquatic environment. The study area of Lake Markakol and its tributaries seems to be especially suitable because of their insularity and the closed catchment situation with only one outflow.
Addressing this problem requires comprehensive measures such as raising awareness of waste management, improving waste management, encouraging a shift to alternative materials and actively implementing measures to clean up and restore polluted aquatic ecosystems.
The final results emphasize the need to take measures to prevent pollution of water systems and develop strategies to reduce the use of plastic materials in the region. Combating the MP problem requires a comprehensive approach, including the promotion of environmentally friendly consumption and the use of recyclable and biodegradable materials. Limited production and distribution of plastics, of course, would be the best form of prevention!
There is a need to create and improve systems for collection, recycling and disposal of waste, including plastic garbage. Additionally, it is extremely important to introduce strict laws and regulations on waste management, such as fines for illegal dumping of garbage into water systems.
The implementation of these activities in the future could have a great impact on the development of the system of collection, transportation and recycling of plastic waste, which will have a positive impact on improving the environmental situation in the study area and in all of Kazakhstan. This will contribute to achievement of the goals of the “green” economy. The promotion and support of scientific research on plastic pollution of ecosystems could strengthen the importance of this work in the future and become the basis for further research and practice.
Until there are clear restrictions on the production and use of plastics, we need to preserve our natural heritage. For this purpose, special protection measures are being implemented in the territories of UNESCO sites and other equally important natural areas. But unfortunately, the results of this work show that this has not been sufficient. Therefore, continued monitoring of plastics in aquatic ecosystems is an important step toward understanding the extent of the problems and developing effective pollution management in combination with prevention strategies.
Conceptualization, A.M. (Azamat Madibekov), L.I. and C.O.; Methodology, L.I. and C.O.; Software, A.Z. and S.Z.; Validation, A.M. (Azamat Madibekov) and L.I.; Formal analysis, A.M. (Azamat Madibekov), B.S., A.Z., S.Z. and A.M. (Aisha Madibekova); Investigation, A.M. (Azamat Madibekov), B.S., A.Z., S.Z. and A.M. (Aisha Madibekova); Resources, A.M. (Azamat Madibekov); Data curation, A.M. (Azamat Madibekov), L.I. and C.O.; Writing—original draft, A.M. (Azamat Madibekov), L.I. and C.O.; Writing—review & editing, A.M. (Azamat Madibekov), L.I. and C.O.; Supervision, A.M. (Azamat Madibekov); Project administration, A.M. (Azamat Madibekov); Funding acquisition, A.M. (Azamat Madibekov), L.I. and C.O. All authors have read and agreed to the published version of the manuscript.
Not applicable.
Not applicable.
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.
The authors declare no conflict of interest.
Footnotes
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
Enlarge this image.Figure 1. Block diagram of MP sampling conditions in the Lake Markakol and tributaries study area (Kazakhstan).
Enlarge this image.Figure 2. Sampling locations in lake zones of Lake Markakol and inflowing rivers.
Enlarge this image.Figure 3. Concentrations of MPs detected in the water zones of Lake Markakol and its main tributaries.
Enlarge this image.Figure 3. Concentrations of MPs detected in the water zones of Lake Markakol and its main tributaries.
Enlarge this image.Figure 4. Visual documentation of selected samples from Lake Markakol. Plastic particles of different sizes found in water samples under a microscope with a magnification of 40× (photo credit: A. Madibekova).
Concentrations and sizes of MPs in tributaries and in Lake Markakol (
| Sampling Location | Concentration (mg/m3) | Total (mg/m3) | ||||
|---|---|---|---|---|---|---|
| 0.315–1.0 | 1.0–5.0 | 5.0–10 | 10–25 | ˃25 | ||
| Main Tributaries Flowing into Lake Markakol | ||||||
| Urunhaika River | 11.5 | 56.8 | none | none | 368.0 | 850.1 |
| Tikhushka River | 30.2 | 67.7 | none | none | none | |
| Zhirelka River | 24.0 | 43.8 | none | none | none | |
| Topolevka River | 26.2 | 130.9 | none | none | none | |
| Yelovka River | 12.6 | none | none | none | none | |
| Matabai River | 20.9 | 57.4 | none | none | none | |
| Kalzhyr River | not found | |||||
| Water Area of Lake Markakol | ||||||
| Zone 1 | 165.5 | 121.3 | none | none | none | 837.5 |
| Zone 2 | 53.0 | 147.2 | none | none | none | |
| Zone 3 | 37.6 | 4.0 | none | none | none | |
| Zone 4 | 151.2 | 6.1 | none | none | none | |
| Zone 5 | 113.4 | 38.2 | none | none | none | |
On-site conditions, observations and counts during plastic sampling at Lake Markakol water area zones and main lake tributary rivers, as well as the effluent of the Kalzhyr River.
| Sampling Location | Trawling Time/Distance (min/m) | Weather Conditions | Air Temperature (°C) | Types of Plastic Discovered | Plastic Size | Quantity of Plastic |
|---|---|---|---|---|---|---|
| The Main Tributaries Flowing into Lake Markakol | ||||||
| Urunhaika River | 15 | cloudy | 26 | Fishing line nets, foam balls, plastic bags, plastic bottles, wrappers, labels, food packaging | 0.5–300 | 125 |
| Tikhushka River | clear, no precipitation | 29 | 0.5–3.8 | 143 | ||
| Zhirelka River | clear, no precipitation | 29 | 0.4–3.6 | 117 | ||
| Topolevka River | slightly cloudy, no precipitation | 26 | 0.5–4.2 | 178 | ||
| Yelovka River | slightly cloudy, no precipitation | 26 | 0.5–3.9 | 47 | ||
| Matabai River | slightly cloudy, no precipitation | 33 | 0.4–4.4 | 121 | ||
| Kalzhyr River | slightly cloudy, no precipitation | 33 | not found | |||
| Water Area of Lake Markakol | ||||||
| Zone 1 | 15/438 | cloudy, no precipitation | 26 | Fishing line nets, foam balls, plastic bags | 0.4–3.1 | 79 |
| Zone 2 | 15/841 | clear, no precipitation | 31 | 0.5–4.4 | 53 | |
| Zone 3 | 15/593 | clear, no precipitation | 30 | 0.4–3.1 | 182 | |
| Zone 4 | 15/512 | cloudy, no precipitation | 33 | 0.4–4.3 | 38 | |
| Zone 5 | 15/736 | clear, no precipitation | 30 | 0.4–3.7 | 126 | |
References
1. Kaufman, M. The First Century of Plastics. Op. Cit.; 1963; 130, pp. 3-67.
2. Rasmussen, S.C. From Parkesine to Celluloid: The Birth of Organic Plastics. Angew. Chem.; 2021; 60, pp. 8012-8016. [DOI: https://dx.doi.org/10.1002/anie.202015095] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/33576547]
3. Mossman, S. Early Plastics. Ferrum Nachrichten aus der Eisenbibliothek, Stiftung der Georg Fischer AG perspect. E–Periodica; 2017; 89, pp. 1850-1950. [DOI: https://dx.doi.org/10.5169/seals-685412]
4. Geyer, R.; Jambeck, J.R.; Law, K.L. Production, use, and fate of all plastics ever made. Sci. Adv.; 2017; 3, e1700782. [DOI: https://dx.doi.org/10.1126/sciadv.1700782] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/28776036]
5. Trading Company Ataman Chemistry. Available online: https://www.atamanchemicals.com/nitrocellulose_u25654/?lang=RU (accessed on 9 February 2024).
6. Chandler, C.F. Presentation Address. Ind. Eng. Chem.; 1914; 6, pp. 156-158. [DOI: https://dx.doi.org/10.1021/ie50062a020]
7. Website REUTERS. Available online: https://www.reuters.com/world/india/india-bans-single-use-plastic-combat-pollution-2022-07-01/ (accessed on 10 September 2024).
8. Lebreton, L.; Zwet, V.D.; Damsteeg, J.W.; Slat, B.; Andrady, A.; Reisser, J. River plastic emissions to the world’s oceans. Nat. Commun.; 2017; 8, 15611. [DOI: https://dx.doi.org/10.1038/ncomms15611]
9. Zheng, J.; Suh, S. Strategies to reduce the global carbon footprint of plastics. Nat. Clim. Change; 2019; 9, pp. 374-378. [DOI: https://dx.doi.org/10.1038/s41558-019-0459-z]
10. World Economic Forum, Ellen MacArthur Foundation and McKinsey & Company, The New Plastics Economy: Rethinking the Future of Plastics 2016. Available online: https://www.ellenmacarthurfoundation.org/the-new-plastics-economy-rethinking-the-future-of-plastics (accessed on 5 February 2024).
11. Ryberg, M.W.; Laurent, A.; Hauschild, M. Mapping of global plastics value chain and plastics losses to the environment (with a particular focus on marine environment). UNEP Nairobi Kenya; 2018; 99.Available online: https://wedocs.unep.org/20.500.11822/26745 (accessed on 10 September 2024).
12. Brunner, P.H.; Rechberger, H. Practical Handbook of Material Flow Analysis: For Environmental, Resource, and Waste Engineers; CRC Press: Boca Raton, FL, USA, 2016; 311.Available online: https://iopscience.iop.org/article/10.1088/1748-9326/ab9e1e/pdf (accessed on 10 September 2024).
13. Schwarz, A.E.; Ligthart, T.N.; Boukris, E.; Harmelen, T. Sources, transport, and accumulation of different types of plastic litter in aquatic environments: A review study. Mar. Pollut. Bull.; 2019; 143, pp. 92-100. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2019.04.029]
14. Law, K.L. Plastics in the marine environment. Annu. Rev. Mar. Sci.; 2017; 9, pp. 205-229. [DOI: https://dx.doi.org/10.1146/annurev-marine-010816-060409]
15. Notten, P. Addressing marine plastics: A systemic approach—Stocktaking report. UNEP Nairobi Kenya; 2018; 89.Available online: https://www.unep.org/resources/report/addressing-marine-plastics-systemic-approach-stocktaking-report (accessed on 7 February 2024).
16. Chae, Y.; An, Y.J. Current research trends on plastic pollution and ecological impacts on the soil ecosystem: A review. Environ. Pollut.; 2018; 240, pp. 387-395. [DOI: https://dx.doi.org/10.1016/j.envpol.2018.05.008] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/29753246]
17. Cole, M.; Lindeque, P.; Halsband, C.; Galloway, T.S. Microplastics as contaminants in the marine environment: A review. Mar. Pollut. Bull.; 2011; 62, pp. 2588-2597. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2011.09.025]
18. Andrady, A.L. Microplastics in the marine environment. Mar. Pollut. Bull.; 2011; 62, pp. 1596-1605. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2011.05.030] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/21742351]
19. Gregory, M.R.; Andrady, A.L. Plastics and the Environment; John Wiley and Sons: Hoboken, NJ, USA, 2003; 747.
20. Napper, I.E.; Thompson, R.C. Plastic Debris in the Marine Environment: History and Future Challenges. Glob. Chall.; 2020; 64, 1900081. [DOI: https://dx.doi.org/10.1002/gch2.201900081]
21. Corcoran, P.L.; Biesinger, M.C.; Grifi, M. Plastics and beaches: A degrading relationship. Mar. Pollut. Bull.; 2009; 58, 80. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2008.08.022]
22. Bergmann, M.; Gutow, L.; Klages, M. Marine Anthropogenic Litter; Springer: Cham, Switzerland, 2015; 447. [DOI: https://dx.doi.org/10.1007/978-3-319-16510-3]
23. Lobelle, D.; Cunliffe, M. Early microbial biofilm formation on marine plastic debris. Mar. Pollut. Bull.; 2011; 62, pp. 197-200. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2010.10.013]
24. Fazey, F.M.; Ryan, P.G. Biofouling on buoyant marine plastics: An experimental study into the effect of size on surface longevity. Environ. Pollut.; 2016; 210, pp. 354-360. [DOI: https://dx.doi.org/10.1016/j.envpol.2016.01.026]
25. Liu, M.; Lu, S.; Song, Y.; Lei, L.; Hu, J.; Lv, W.; Zhou, W.; Cao, C.; Shi, H.; Yang, X. et al. Microplastic and mesoplastic pollution in farmland soils in suburbs of Shanghai, China. Environ. Pollut.; 2018; 242, pp. 855-862. [DOI: https://dx.doi.org/10.1016/j.envpol.2018.07.051]
26. Hidalgo-Ruz, V.; Gutow, L.; Thompson, R.C.; Thiel, M. Microplastics in the marine environment: A review of the methods used for identification and quantification. Environ. Sci. Technol.; 2012; 46, pp. 3060-3075. [DOI: https://dx.doi.org/10.1021/es2031505]
27. Zhang, K.; Xiong, X.; Hu, H.; Wu, C.; Bi, Y.; Wu, Y.; Zhou, B.; Lam, P.K.; Liu, J. Occurrence and Characteristics of Microplastic Pollution in Xiangxi Bay of Three Gorges Reservoir, China. Environ. Sci. Technol.; 2017; 51, pp. 3794-3801. [DOI: https://dx.doi.org/10.1021/acs.est.7b00369] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/28298079]
28. Barnes, D.K.; Galgani, F.; Thompson, R.C.; Barlaz, M. Accumulation and fragmentation of plastic debris in global environments. Philos. Trans. R Soc. Lond. B Biol. Sci.; 2009; 364, pp. 1985-1998. [DOI: https://dx.doi.org/10.1098/rstb.2008.0205]
29. Carpenter, E.J.; Smith, K.L. Plastic on the Sargasso Sea Surface. Science; 1972; 175, pp. 1240-1241. [DOI: https://dx.doi.org/10.1126/science.175.4027.1240] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/5061243]
30. Thompson, R.C.; Olsen, Y.; Mitchell, R.P.; Davis, A.; Rowland, S.J.; John, A.W.; McGonigle, D.; Russell, A.E. Lost at sea: Where is all the plastic?. Science; 2004; 304, 838. [DOI: https://dx.doi.org/10.1126/science.1094559] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/15131299]
31. Derraik, J.G. The pollution of the marine environment by plastic debris: A review. Mar. Pollut. Bull.; 2002; 44, pp. 842-852. [DOI: https://dx.doi.org/10.1016/S0025-326X(02)00220-5] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/12405208]
32. Law, K.L.; Thompson, R.C. Microplastics in the seas. Science; 2014; 345, pp. 144-145. [DOI: https://dx.doi.org/10.1126/science.1254065]
33. Browne, M.A.; Crump, P.; Niven, S.J.; Teuten, E.; Tonkin, A.; Galloway, T.; Thompson, R. Accumulation of microplastic on shorelines woldwide: Sources and sinks. Environ. Sci. Technol.; 2011; 45, pp. 9175-9179. [DOI: https://dx.doi.org/10.1021/es201811s]
34. Cózar, A.; Echevarría, F.; González-Gordillo, J.I.; Irigoien, X.; Ubeda, B.; Hernández-León, S.; Palma, A.T.; Navarro, S.; García-de-Lomas, J.; Ruiz, A. et al. Plastic debris in the open ocean. Proc. Nat. Acad. Sci. USA; 2014; 111, pp. 10239-10244. [DOI: https://dx.doi.org/10.1073/pnas.1314705111]
35. Werner, S.; Budziak, A.; Franeker, V.J.; Galgani, F.; Hanke, G.; Maes, T.; Matiddi, M.; Nilsson, P.; Oosterbaan, L.; Priestland, E. et al. Harm caused by Marine Litter. MSFD GES TG Marine Litter—Thematic Report; JRC Technical Report, EUR 28317 EN European Union: Luxembourg, 2016; 88. [DOI: https://dx.doi.org/10.2788/690366]
36. Van Cauwenberghe, L.; Vanreusel, A.; Mees, J.; Janssen, C.R. Microplastic pollution in deep-sea sediments. Environ. Pollut.; 2013; 182, pp. 495-499. [DOI: https://dx.doi.org/10.1016/j.envpol.2013.08.013]
37. Proceedings of the Workshop on the Fate and Impact of Marine Debris, Honolulu, HI, USA, 27–29 November 1984. Available online: https://repository.library.noaa.gov/view/noaa/5680 (accessed on 2 February 2024).
38. Wagner, M.; Scherer, C.; Alvarez-Muñoz, D.; Brennholt, N.; Bourrain, X.; Buchinger, S.; Fries, E.; Grosbois, C.; Klasmeier, J.; Marti, T. et al. Microplastics in freshwater ecosystems: What we know and what we need to know. Environ. Sci. Eur.; 2014; 26, 12. [DOI: https://dx.doi.org/10.1186/s12302-014-0012-7]
39. Lazar, B.; Gračan, R. Ingestion of marine debris by loggerhead sea turtles, Caretta caretta, in the Adriatic Sea. Mar. Pollut. Bull.; 2011; 62, pp. 43-47. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2010.09.013] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/21036372]
40. Nyaga, M.P.; Shabaka, S.; Oh, S.; Osman, D.M.; Yuan, W.; Zhang, W.; Yang, Y. Microplastics in aquatic ecosystems of Africa: A comprehensive review and meta-analysis. Environ. Res.; 2024; 248, 118307. [DOI: https://dx.doi.org/10.1016/j.envres.2024.118307]
41. Ren, X.; Mao, M.; Feng, M.; Peng, T.; Long, X.; Yang, F. Fate, abundance and ecological risks of microcystins in aquatic environment: The implication of microplastics. Wat. Res.; 2024; 251, 121121. [DOI: https://dx.doi.org/10.1016/j.watres.2024.121121]
42. Ali, N.; Khan, M.H.; Ali, M.; Sidra,; Ahmad, S.; Khan, A.; Nabi, A.F.; Bououdina, M.; Kyzas, G.Z. Insight into microplastics in the aquatic ecosystem: Properties, sources, threats and mitigation strategies. Sci. Total Environ.; 2024; 913, 169489. [DOI: https://dx.doi.org/10.1016/j.scitotenv.2023.169489]
43. Ahmed, A.S.; Billah, M.; Ali, M.; Bhuiyan, K.A.; Guo, L.; Mohinuzzaman, M.; Hossain, M.B.; Rahman, M.S.; Islam, S.; Yan, M. et al. Microplastics in aquatic environments: A comprehensive review of toxicity, removal, and remediation strategies. Sci. Total Environ.; 2023; 162414. [DOI: https://dx.doi.org/10.1016/j.scitotenv.2023.162414]
44. Maharjan, K.K. Microplastics research in Nepal: Present scenario and current gaps in knowledge. Heliyon; 2024; 10, e24956. [DOI: https://dx.doi.org/10.1016/j.heliyon.2024.e24956]
45. Nazifa, R.; Bushra, A.; Fatema, Z.; Jannatul, B.; Samiya, A.; Shams-Forruque, A.; Mofijur, M.; Ashfaque, A.; Chowdhury, F.A. Microplastics as carriers of toxic pollutants: Source, transport, and toxicological effects. Environ. Pollut.; 2024; 343, 123190. [DOI: https://dx.doi.org/10.1016/j.envpol.2023.123190]
46. Long, C.; Shenglu, Z.; Qi, Z.; Bo, S.; Qiqi, Y.; Mengmeng, Z. Global occurrence characteristics, drivers, and environmental risk assessment of microplastics in lakes: A meta-analysis. Environ. Pollut.; 2024; 344, 123321. [DOI: https://dx.doi.org/10.1016/j.envpol.2024.123321]
47. Yang, S.; Zhou, M.; Chen, X.; Hu, L.; Xu, Y.; Fu, W.; Li, C. A comparative review of microplastics in lake systems from different countries and regions. Chemosphere; 2022; 286, 131806. [DOI: https://dx.doi.org/10.1016/j.chemosphere.2021.131806]
48. Nikitin, O.V.; Latypova, V.Z.; Minnegulova, L.M.; Nasyrova, E.I. Pollution of fresh water by microplastics: The need for monitoring and control. Chem. Eng. Ecol.; 2019; pp. 154-160. Available online: https://www.elibrary.ru/item.asp?id=42498429 (accessed on 10 September 2024).
49. Dusaucy, J.; Gateuille, D.; Perrette, Y.; Naffrechoux, E. Microplastic pollution of worldwide lakes. Environ. Pollut.; 2021; 284, 117075. [DOI: https://dx.doi.org/10.1016/j.envpol.2021.117075] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/33894537]
50. Cai, X.; Chen, H.; Huang, B.; Lu, J. Analysis on advances and characteristics of microplastic pollution in China’s lake ecosystems. Ecotoxicol. Environ. Saf.; 2022; 232, 113254. [DOI: https://dx.doi.org/10.1016/j.ecoenv.2022.113254]
51. Kumar, V.; Umesh, M.; Chakraborty, P.; Sharma, P.; Sarojini, S.; Basheer, T.; Kaur, K.; Pasrija, R.; Barcelo, D. Origin, ecotoxicity, and analytical methods for microplastic detection in aquatic systems. TrAC Trends Anal. Chem.; 2024; 170, 117392. [DOI: https://dx.doi.org/10.1016/j.trac.2023.117392]
52. Mohan, K.; Lakshmanan, V.R. A critical review of the recent trends in source tracing of microplastics in the environment. Environ. Res.; 2023; 239, 117394. [DOI: https://dx.doi.org/10.1016/j.envres.2023.117394] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/37838194]
53. Zhang, F.; Guo, X.; Zhang, J.; Zhang, Z. Microplastics in Qinghai-Tibet Plateau and Yunnan-Guizhou Plateau lakes, China. Sci. Total Environ.; 2024; 915, 169978. [DOI: https://dx.doi.org/10.1016/j.scitotenv.2024.169978]
54. Tran-Nguyen, Q.A.; Le, T.M.; Nguyen, H.N.; Nguyen, Q.T.; Trinh-Dang, M. Microplastics in the surface water of urban lakes in central Vietnam: Pollution level, characteristics, and ecological risk assessment. Case Stud. Chem. Environ. Eng.; 2024; 9, 100622. [DOI: https://dx.doi.org/10.1016/j.cscee.2024.100622]
55. Ephsy, D.; Raja, S. Characterization of microplastics and its pollution load index in freshwater Kumaraswamy Lake of Coimbatore, India. Environ. Toxicol. Pharmacol.; 2023; 101, 104207. [DOI: https://dx.doi.org/10.1016/j.etap.2023.104207]
56. Conowall, P.; Schreiner, K.M.; Minor, E.C.; Hrabik, T.; Schoenebeck, C.W. Variability of microplastic loading and retention in four inland lakes in Minnesota, USA. Environ. Pollut.; 2023; 328, 121573. [DOI: https://dx.doi.org/10.1016/j.envpol.2023.121573]
57. Anagha, P.L.; Viji, N.V.; Devika, D.; Ramasamy, E.V. Distribution and abundance of microplastics in the water column of Vembanad Lake–A Ramsar site in Kerala, India. Mar. Pollut. Bull.; 2023; 134, 115433. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2023.115433]
58. Yu, J.T.; Helm, P.A.; Diamond, M.L. Source-specific categorization of microplastics in nearshore surface waters of the Great Lakes. J. Great Lakes Res.; 2024; 50, 102256. [DOI: https://dx.doi.org/10.1016/j.jglr.2023.102256]
59. Xiong, X.; Tappenbeck, T.H.; Wu, C.; Elser, J.J. Microplastics in Flathead Lake, a large oligotrophic mountain lake in the USA. Environ. Pollut.; 2022; 306, 119445. [DOI: https://dx.doi.org/10.1016/j.envpol.2022.119445] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/35550134]
60. Madibekov, A.S.; Ismukhanova, L.T.; Zhadi, A.O.; Sultanbekova, B.M.; Zhaparkulova, E.D. Microplastics in the aquatic environment: Overview of the problem and current research areas. NEWS of NAS RK. Ser. Geol. Tech. Sci.; 2023; 2, pp. 149-159. [DOI: https://dx.doi.org/10.32014/2023.2518-170X.290]
61. Tang, K.D. Microplastics in and Near Landlocked Countries of Central and East Asia: A Review of Occurrence and Characteristics. Trop. Aquat. Soil Pollut.; 2023; 3, pp. 120-123. [DOI: https://dx.doi.org/10.53623/tasp.v3i2.262]
62. Baimukanov, M.T. How to preserve the Caspian seal (Pusa caspica). News NAS RK. Ser. Biol. Med.; 2017; 324, pp. 100-101.
63. Baimukanov, M.T.; Baimukanova, J.M. On plastic pollution and its potential impact on the biodiversity of the Caspian Sea. Sci. Tech. J. ”News Sci. Kazakhstan”; 2021; 149, pp. 174-179.
64. Salikova, N.S.; Rodrigo-Ilarri, J.; Rodrigo-Clavero, M.E.; Urazbayeva, S.E.; Askarova, A.Z.; Magzhanov, K.M. Environmental Assessment of Microplastic Pollution Induced by Solid Waste Landfills in the Akmola Region (North Kazakhstan). Water; 2023; 15, 2889. [DOI: https://dx.doi.org/10.3390/w15162889]
65. Frank, Y.; Khusanov, A.; Yuldashov, M.; Vorobiev, E.; Rakhmatullina, S.; Rednikin, A.; Tashbaev, S.; Mamatkarimova, S.; Ruchkina, K.; Namozov, S. et al. Microplastics in the Syrdarya River Tributaries, Uzbekistan. Water; 2023; 15, 3698. [DOI: https://dx.doi.org/10.3390/w15203698]
66. From the Official Site of the Information-Legal System of Normative-Legal Acts of RK “Adilet” On Approval by the Republic of Kazakhstan of the Convention on Biological Diversity and Organisation of Implementation of Obligations Provided by it. Decree of the Cabinet of Ministers of the Republic of Kazakhstan from 19 August 1994; p. 918. Available online: https://adilet.zan.kz/rus/docs/P940000918_ (accessed on 9 February 2024).
67. Semenova, V.A. Surface water resources of the USSR. Altai and Western Siberia, Gorny Altai and Upper Irtysh, Leningrad. Gidrometeoizdat; 1969; 15, 318.
68. Filonets, P.P. Essays on the geography of inland waters of Central, Southern and Eastern Kazakhstan. Alma-Ata. Science; 1981; 3, 186.
69. Official Website of the RGU “Markakol State Nature Reserve”. Available online: https://markakol-zapovednik.kz/ru/o-nas.html (accessed on 2 February 2024).
70. Berezovikov, N.N.; Zinchenko, Y.K.; Zinchenko, E.S. Markakol Reserve. Reserves of the USSR. Reserves of Central Asia and Kazakhstan. Moskow, Soviet Union 1990, 114–128. Available online: https://www.undp.org/sites/g/files/zskgke326/files/migration/kz/7059-16397.pdf (accessed on 10 December 2023).
71. Surface Water Resources of the USSR. Altai and Western Siberia. Mountain Altai and Upper Irtysh. Part 1; Semenova, V.A. Leningrad State University: Leningrad, Soviet Union, 1969; Volume 15, 318.Available online: https://disk.yandex.kz/d/UMicA14_a2Y5F (accessed on 3 April 2024).
72. Tamminga, M.; Stoewer, S.C.; Fischer, E.K. On the representativeness of pump water samples versus manta sampling in microplastic analysis. Environ. Pollut.; 2019; 254, 112970. [DOI: https://dx.doi.org/10.1016/j.envpol.2019.112970]
73. Eriksen, M.; Lebreton, L.C.M.; Carson, H.S.; Thiel, M.; Moore, C.J.; Borerro, J.C.; Galgani, F.G.; Ryan, P.G.; Reisser, J.W. Plastic pollution in the world’s oceans: More than 5 trillion plastic pieces weighing over 250,000 tons afloat at sea. PLoS ONE; 2014; 9, e111913. [DOI: https://dx.doi.org/10.1371/journal.pone.0111913] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/25494041]
74. Lusher, A.L.; Tirelli, V.; O’Connor, I.; Officer, R. Microplastics in Arctic polar waters: The first reported values of particles in surface and sub-surface samples. Sci. Rep.; 2015; 5, 14947. [DOI: https://dx.doi.org/10.1038/srep14947] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/26446348]
75. Setälä, O.; Magnusson, K.; Lehtiniemi, M.; Norén, F. Distribution and abundance of surface water microlitter in the Baltic Sea: A comparison of two sampling methods. Mar. Pollut. Bull.; 2016; 110, pp. 177-183. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2016.06.065]
76. Zobkov, M.B.; Esiukova, E.E. Microplastics in the marine environment: A review of methods for sampling, preparation and analysis of water, bottom sediments and shore sediments. Oceanology; 2018; 1, 53.
77. Zobkov, M.; Esiukova, E. Evaluation of the Munich Plastic Sediment Separator efficiency in extraction of microplastics from natural marine bottom sediments. Limnol. Oceanogr. Methods; 2017; 15, pp. 967-978. [DOI: https://dx.doi.org/10.1002/lom3.10217]
78. Zobkov, M.; Zobkova, M.; Galakhina, N.; Efremova, T. Method for microplastics extraction from Lake sediments. MethodsX; 2020; 7, 101140. [DOI: https://dx.doi.org/10.1016/j.mex.2020.101140] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/33294398]
79. Kroon, F.; Motti, C.; Talbot, S.; Sobral, P.; Puotinen, M. A workflow for improving estimates of microplastic contamination in marine waters: A case study from North-Western Australia. Environ. Pollut.; 2018; 238, pp. 26-38. [DOI: https://dx.doi.org/10.1016/j.envpol.2018.03.010] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/29533881]
80. Mu, J.; Zhang, S.; Qu, L.; Jin, F.; Fang, C.; Ma, X.; Zhang, W.; Wang, J. Microplastics abundance and characteristics in surface waters from the Northwest Pacific, the Bering Sea, and the Chukchi Sea. Mar. Pollut. Bull.; 2019; 143, pp. 58-65. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2019.04.023]
81. Stock, F.; Kochleus, C.; Bänsch-Baltruschat, B.; Brennholt, N.; Reifferscheid, G. Sampling techniques and preparation methods for microplastic analyses in the aquatic environmente A review. TrAC Trends Anal. Chem.; 2019; 113, pp. 84-92. [DOI: https://dx.doi.org/10.1016/j.trac.2019.01.014]
82. Sagawa, N.; Kawaai, K.; Hinata, H. Abundance and size of microplastics in a coastal sea: Comparison among bottom sediment, beach sediment, and surface water. Mar. Pollut. Bull.; 2018; 133, pp. 532-542. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2018.05.036]
83. Boerger, C.M.; Lattin, G.L.; Moore, S.L.; Moore, C.J. Plastic ingestion by planktivorous fishes in the North Pacific Central Gyre. Mar. Pollut. Bull.; 2010; 60, pp. 2275-2278. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2010.08.007] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/21067782]
84. Masura, J.; Baker, J.; Foster, G.; Arthur, C. Laboratory methods for the analysis of microplastics in the marine environment: Recommendations for quantifying synthetic particles in watersand sediments. NOAA Technical Memorandum; NOS-OR&R-48 NOAA Marine Debris Division: Silver Spring, MD, USA, 2015; 31.
85.
86.
87. Esiukova, E. Plastic pollution on the Baltic beaches of Kaliningrad region, Russia. Mar. Pollut. Bull.; 2017; 114, pp. 1072-1080. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2016.10.001] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/27726936]
88. Chubarenko, I.P.; Esiukova, E.E.; Bagaev, A.V.; Bagaeva, M.A.; Grave, A.N. Three-dimensional distribution of anthropogenic microparticles in the body of sandy beaches. Sci. Total Environ.; 2018; 629, pp. 1340-1351. [DOI: https://dx.doi.org/10.1016/j.scitotenv.2018.02.167]
89. Hanvey, J.; Lewis, P.; Lavers, J.; Crosbie, N.; Pozo, K.; Clarke, B. A review of analytical techniques for quantifying microplastics in sediments. Anal. Methods; 2017; 9, 1369. [DOI: https://dx.doi.org/10.1039/C6AY02707E]
90. Hengstmann, E.; Tamminga, M.; Vom, B.C.; Fischer, E.K. Microplastic in beach sediments of the Isle of Rügen (Baltic Sea)—Implementing a novel glass elutriation column. Mar. Pollut. Bull.; 2018; 126, pp. 263-274. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2017.11.010]
91. Esiukova, E.; Khatmullina, L.; Lobchuk, O.; Grave, A.; Kileso, A.; Haseler, M.; Zyubin, A.; Chubarenko, I. From macro to micro: Dataset on plastic contamination along and across a sandy tide-less coast (the Curonian Spit, the Baltic Sea). Data Brief; 2020; 30, 105635. [DOI: https://dx.doi.org/10.1016/j.dib.2020.105635]
92. Ng, K.L.; Obbard, J.P. Prevalence of microplastics in Singapore’s coastal marine environment. Mar. Pollut. Bull.; 2006; 52, pp. 761-767. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2005.11.017]
93. Collignon, A.; Hecq, J.H.; Glagani, F.; Voisin, P.; Collard, F.; Goffart, A. Neustonic microplastic and zooplankton in the North Western Mediterranean Sea. Mar. Pollut. Bull.; 2012; 64, pp. 861-864. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2012.01.011]
94. Song, Y.K.; Hong, S.H.; Jang, M.; Han, G.M.; Rani, M.; Lee, J.; Shim, W.J. A comparison of microscopic and spectroscopic identification methods for analysis of microplastics in environmental samples. Mar. Pollut. Bull.; 2015; 93, pp. 202-209. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2015.01.015]
95. Tagg, A.; Harrison, J.P.; Ju-Nam, Y.; Sapp, M.; Bradley, E.L.; Sinclair, C.J.; Ojeda, J.J. Fenton’s reagent for the rapid and efficient isolation of microplastics from wastewater. Chem. Commun.; 2017; 53, pp. 372-375. [DOI: https://dx.doi.org/10.1039/C6CC08798A]
96. Bergmann, M.; Wirzberger, V.; Krumpen, T.; Lorenz, C.; Primpke, S.; Tekman, M.B.; Gerdts, G. High quantities of microplastic in Arctic Deep-Sea sediments from the HAUSGARTEN observatory. Environ. Sci. Tech.; 2017; 51, pp. 11000-11010. [DOI: https://dx.doi.org/10.1021/acs.est.7b03331]
97. Rocha-Santos, T.; Duarte, A.C. A critical overview of the analytical approaches to the occurrence, the fate and the behavior of microplastics in the environment. TrAC Trends Anal. Chem.; 2015; 65, pp. 47-53. [DOI: https://dx.doi.org/10.1016/j.trac.2014.10.011]
98. Coppock, R.L.; Cole, M.; Lindeque, P.K.; Queirós, A.M.; Galloway, T.S. A small-scale, portable method for extracting microplastics from marine sediments. Environ. Pollut.; 2017; 230, pp. 829-837. [DOI: https://dx.doi.org/10.1016/j.envpol.2017.07.017] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/28734264]
99. Fries, E.; Dekiff, J.H.; Willmeyer, J.; Nülle, M.T.; Ebert, M.; Remy, D. Identification of polymer types and additives in marine microplastic particles using pyrolysis-GC/MS and scanning electron microscopy. Environ. Sci. Process Impact.; 2013; 15, pp. 1949-1956. [DOI: https://dx.doi.org/10.1039/c3em00214d]
100. Norén, F. Small plastic particles in Coastal Swedish Waters. KIMO report. 2008; Available online: https://www.semanticscholar.org/paper/Small-plastic-particles-in-Coastal-Swedish-waters-.-Nor%C3%A9n/8f1a49cced3d69e6c356bfb4ad3521f81549255e (accessed on 10 September 2024).
101. Barrows, A.P.W.; Cathey, S.E.; Petersen, C.W. Marine environment microfiber contamination: Global patterns and the diversity of microparticle origins. Environ. Pollut.; 2018; 237, pp. 275-284. [DOI: https://dx.doi.org/10.1016/j.envpol.2018.02.062]
102. Frias, J.; Pagter, E.; Nash, R.; O’Connor, I.; Carretero, O.; Filgueiras, A.; Viñas, L.; Gago, J.; Antunes, J.; Bessa, F. et al. Standardised protocol for monitoring microplastics in sediments. JPI-Oceans BASEMAN project. 2018; Available online: https://www.researchgate.net/publication/326552185_Standardised_protocol_for_monitoring_microplastics_in_sediments?channel=doi&linkId=5b572280aca27217ffb7ccb2&showFulltext=true (accessed on 10 September 2024).
103. Matsuguma, Y.; Takada, H.; Kumata, H.; Kanke, H.; Sakurai, S.; Suzuki, T.; Itoh, M.; Okazaki, Y.; Boonyatumanond, R.; Zakaria, M.P. et al. Microplastics in Sediment Cores from Asia and Africa as Indicators of Temporal Trends in Plastic Pollution. Arch Environ. Contam. Toxicol.; 2017; 73, pp. 230-239. [DOI: https://dx.doi.org/10.1007/s00244-017-0414-9]
104. Weber, C.J.; Opp, C. Spatial patterns of mesoplastics and coarse microplastics in floodplain soils as resulting from land use and fluvial processes. Environ. Pollut.; 2020; 267, 115390. [DOI: https://dx.doi.org/10.1016/j.envpol.2020.115390]
105. Weber, C.J.; Bigalke, M. Opening Space for Plastics—Why Spatial, Soil and Land Use Data Are Important to Understand Global Soil (Micro)Plastic Pollution. Microplastics; 2022; 1, pp. 610-625. [DOI: https://dx.doi.org/10.3390/microplastics1040042]
106. Weber, C.J.; Opp, C.; Prume, J.A.; Koch, M.; Andersen, T.J.; Chifflard, P. Deposition and in-situ translocation of microplastics in floodplain soils. Sci. Total Environ.; 2022; 819, 152039. [DOI: https://dx.doi.org/10.1016/j.scitotenv.2021.152039]
107. Evangeliou, N.; Grythe, H.; Klimont, Z.; Heyes, C.; Eckhardt, S.; Lopez-Aparicio, S.; Stohl, A. Atmospheric transport is a major pathway of microplastics to remote regions. Nat. Commun.; 2020; 11, 3381. [DOI: https://dx.doi.org/10.1038/s41467-020-17201-9]
108. Malygina, N.; Mitrofanova, E.; Kuryatnikova, N.; Biryukov, R.; Zolotov, D.; Pershin, D.; Chernykh, D. Microplastic Pollution in the Surface Waters from Plain and Mountainous Lakes in Siberia, Russia. Water; 2021; 13, 2287. [DOI: https://dx.doi.org/10.3390/w13162287]
109. Potapskaya, N.V.; Kulikova, N.N.; Timoshkin, O.A.; Zaitseva, E.P.; Nepokrytykh, A.V.; Malnik, V.V. Studies in the Baikal basin assessment of consumption waste accumulation in the coastal zone of Lake Baikal and the Selenga River delta. Sci. J. Geogr. Nat. Resour.; 2016; 1, pp. 62-69.
110. Waste Audit on the Shores of Lake Baikal in Russia. 2019; Available online: https://media.greenpeace.org/archive/Waste-Audit-on-the-Shores-of-Lake-Baikal-in-Russia-27MZIFJ89TY7D.html (accessed on 2 February 2024).
111. Ilyina, O.V.; Kolobov, M.Y.; Ilyinsky, V.V. Plastic pollution of coastal surface waters of the middle and southern Baikal. Wat. Res.; 2021; 48, pp. 42-51. [DOI: https://dx.doi.org/10.1134/S0097807821010188]
112. Bertoldi, C.; Lara, L.Z.; Mizushima, F.A.L.; Martins, F.C.G.; Battisti, M.A.; Hinrichs, R.; Fernandes, A.N. First evidence of microplastic contamination in the freshwater of Lake Guaíba, Porto Alegre, Brazil. Sci. Total Environ.; 2021; 759, 143503. [DOI: https://dx.doi.org/10.1016/j.scitotenv.2020.143503]
113. Dong, M.; Luo, Z.; Jiang, Q.; Xing, X.; Zhang, Q.; Sun, Y. The rapid increases in microplastics in urban lake sediments. Sci. Rep.; 2020; 10, 848. [DOI: https://dx.doi.org/10.1038/s41598-020-57933-8]
114. Egessa, R.; Nankabirwa, A.; Ocaya, H.; Pabire, W.G. Microplastic pollution in surface water of Lake Victoria. Sci. Total Environ.; 2020; 741, 140201. [DOI: https://dx.doi.org/10.1016/j.scitotenv.2020.140201]
115. Patricia, L.; Corcoran, T.N.; Trevor, C.; Mary, J.W.; Paul, A.H.; Chris, H.M. Hidden plastics of Lake Ontario, Canada and their potential preservation in the sediment record. Environ. Pollut.; 2015; 204, pp. 17-25. [DOI: https://dx.doi.org/10.1016/j.envpol.2015.04.009]
116. Pan, T.; Liao, H.; Yang, F.; Sun, F.; Guo, Y.; Yang, H.; Feng, D.; Zhou, X.; Wang, Q. Review of microplastics in lakes: Sources, distribution characteristics, and environmental effects. Carbon Res.; 2023; 2, 25. [DOI: https://dx.doi.org/10.1007/s44246-023-00057-1]
117. Nava, V.; Chandra, S.; Aherne, J.; Alfonso, M.B.; Antão-Geraldes, A.M.; Attermeyer, K.; Bao, R.; Bartrons, M.; Berger, S.A.; Biernaczyk, M. et al. Plastic debris in lakes and reservoirs. Nature; 2023; 619, pp. 317-322. [DOI: https://dx.doi.org/10.1038/s41586-023-06168-4]
118. Free, C.M.; Jensen, O.P.; Mason, S.A.; Eriksen, M.; Williamson, N.J.; Boldgiv, B. High-levels of microplastic pollution in a large, remote, mountain lake. Mar. Pollut. Bull.; 2014; 85, pp. 156-163. [DOI: https://dx.doi.org/10.1016/j.marpolbul.2014.06.001]
© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.
Details
; Opp, Christian 2
; Sultanbekova, Botakoz 1 ; Zhadi, Askhat 3 ; Zhumatayev, Serik 4
; Madibekova, Aisha 5 1 Laboratory of Hydrochemistry and Environmental Toxicology, Institute of Geography and Water Security JSC, Almaty 050010, Kazakhstan;
2 Faculty of Geography, Philipps-Universität Marburg, D-35032 Marburg, Germany
3 Water, Land and Forest Resources Faculty, Department Water Resources and Reclamation, Kazakh National Agrarian Research University, Almaty 050013, Kazakhstan;
4 Laboratory of Hydrochemistry and Environmental Toxicology, Institute of Geography and Water Security JSC, Almaty 050010, Kazakhstan;
5 Department of Meteorology and Hydrology, Al-Farabi Kazakh National University, Almaty 050010, Kazakhstan;