Critical environmental factors for photosynthetic organisms of the Shardara Reservoir, Kazakhstan

In summer 2015, the distribution of structural indicators of phytoplankton and the macrophytes overgrowth in the Shardara Reservoir's water independent of external factors was studied. Phytoplankton was represented by 78 species; green algae dominated. The abundance of community was 544.0 mln. cells m-3, with biomass at 626.1 mg m-3. Macrophytes Potamogeton natans L. and Potamogeton malajanus L. massively developed on the eastern shallow parts and in bays of the southwestern part of the reservoir. Our research showed that the biotopes inhabited by macrophytes were generally characterized by relatively higher concentrations of nitrite, phosphate, and zinc. The structure of phytoplankton was dependent on many factors, among which the most important were the water temperature and heavy metals. The warm-water status of the Shardara Reservoir was reflected in the dominance of green algae and dinoflagellates. With relatively high concentrations of heavy metals in the ecosystem, their impact on phytoplankton was neutralized by the complex nature of pollution, which included the increased number of organic substances. The impact of toxicants was not traced when analyzing the diversity and abundance of phytoplankton. The prevalence of facultative heterotrophs among the diatoms served as an indirect indication of the presence of toxic substances in the ecosystem. The dimensional structure of phytoplankton changed under the influence of cadmium in size reduction, and that may be the adaptive restructuring of the community in response to the toxic stress. Therefore, we may emphasize the essential indicative importance of size parameters of communities, including the Clarke's W-statistics and Δ-Shannon-Weaver

Spatial Distribution of the Taxonomic Diversity of Phytoplankton and Bioindication of the Shallow Protected Lake Borovoe in the Burabay National Natural Park, Northern Kazakhstan

The Burabay National Natural Park unites six lakes located among the steppe landscape, with Lake Borovoe being the most visited among them. The phytoplankton of the protected Lake Borovoe was examined in the summer season of 2019, at eight stations, which were defined for the first time as the monitoring sites on the lake surface. Altogether, 72 algae and cyanobacteria species from seven taxonomic phyla were found in the Lake Borovoe phytoplankton during the study period. The most species-rich were three phyla: diatoms, green algae, and cyanobacteria. The average phytoplankton abundance was 3012.6 cells L−1, and biomass was 2383.41 mg L−1. The ecological status of the lake in 2019 was assessed based on the species richness, abundance, biomass, and calculated indices of organic pollution and toxic impact. The statistical mapping, calculated community similarity, correlation, and Redundancy Analysis (RDA) revealed zones affected by human impact. These were located in the lake shores and low-alkaline water with the saprobity index of 1.63–2.00. This is typical for naturally clean lakes, indicating the oligotrophic-to-mesotrophic status of the lake during the study period. The increase in cyanobacteria species in coastal communities can be associated with an increase in the biogenic load on the lake ecosystem in recent times. Therefore, our multivariate analysis allowed us to assess the ecological state of Lake Borovoe, which can be the result of the interaction of many external environmental factors, such as climatic conditions, long-term accumulation of organic substances, the intensity and duration of anthropogenic press, and internal lake processes such as the development of algae communities. The results suggest a tendency for the eutrophication of Lake Borovoe to increase because of pollution coming from the human impact zones on the lake shores

Spatial Distribution of the Taxonomic Diversity of Phytoplankton and Bioindication of the Shallow Protected Lake Borovoe in the Burabay National Natural Park, Northern Kazakhstan

The Burabay National Natural Park unites six lakes located among the steppe landscape, with Lake Borovoe being the most visited among them. The phytoplankton of the protected Lake Borovoe was examined in the summer season of 2019, at eight stations, which were defined for the first time as the monitoring sites on the lake surface. Altogether, 72 algae and cyanobacteria species from seven taxonomic phyla were found in the Lake Borovoe phytoplankton during the study period. The most species-rich were three phyla: diatoms, green algae, and cyanobacteria. The average phytoplankton abundance was 3012.6 cells L−1, and biomass was 2383.41 mg L−1. The ecological status of the lake in 2019 was assessed based on the species richness, abundance, biomass, and calculated indices of organic pollution and toxic impact. The statistical mapping, calculated community similarity, correlation, and Redundancy Analysis (RDA) revealed zones affected by human impact. These were located in the lake shores and low-alkaline water with the saprobity index of 1.63–2.00. This is typical for naturally clean lakes, indicating the oligotrophic-to-mesotrophic status of the lake during the study period. The increase in cyanobacteria species in coastal communities can be associated with an increase in the biogenic load on the lake ecosystem in recent times. Therefore, our multivariate analysis allowed us to assess the ecological state of Lake Borovoe, which can be the result of the interaction of many external environmental factors, such as climatic conditions, long-term accumulation of organic substances, the intensity and duration of anthropogenic press, and internal lake processes such as the development of algae communities. The results suggest a tendency for the eutrophication of Lake Borovoe to increase because of pollution coming from the human impact zones on the lake shores

Bioindication of Ecological State and Water Quality by Phytoplankton in the Shardara Reservoir, Kazakhstan

Abstract Altogether 76 species of algae were revealed in 13 sampling stations of the Shardara Reservoir's phytoplankton during summer 2015. Chlorophyta algae prevailed. Bioindication methods were used to characterize the reservoir water quality and trophic level as fresh and mesotrophic. For the first time, we used a new statistical approach in analyzing data on biodiversity and phytoplankton productivity in order to determine the main source of pollution. The spatial maps for different variables together with bioindication results were drawn using the Statistica 12.0 program. As an introduction to the new surface mapping method, we conclude that statistical maps are more representative and correspond better with the environment. The maps helped us to characterize the Shardara Reservoir as freshwater, with the source of pollution coming from the rivers and agricultural channels together with some toxic substances being dissolved at the lower part of the waterbody near the dam. The main self-purification processes in the studied waterbody mostly occur by means of the green planktonic algae at the central part of the reservoir. The present study demonstrated that using the surface mapping method is advisable in assessing the ecological conditions of the waterbody not for individual stations but for the reservoir as a whole. This study confirms our bioindication results on the correlation of water temperature and total dissolved solids, which is strongly related to water mass disturbance by the wind. Statistical mapping also confirms that the bioindication method showed a more detailed picture than standard physico-chemical analysis

Phytoplankton Diversity and Bioindication of the Lakes in the Burabay National Natural Park, Northern Kazakhstan

The problem of assessing the impact of pollution in protected areas prompted us to apply a combined method of bioindication and spatial mapping of phytoplankton data from six lakes in the Burabay National Nature Park in Northern Kazakhstan. The issue of monitoring planning was quite acute for this landscape-homogeneous area among the Kulunda steppes. Phytoplankton in each of the six lakes was collected in the summer season of 2019 at a total of 54 sampling stations. In total, 139 species of algae and cyanobacteria from seven taxonomic phyla were found in the phytoplankton of the Burabay Park during the study period. Three phyla were the richest in species: diatoms, green algae, and cyanobacteria. Based on species richness, abundance, and biomass, as well as bioindicators and calculated indices of organic pollution and toxic effects, the current ecological state of the lake was assessed as being under the influence of pollution, of the mesotrophic type and with a high capacity for self-purification. Statistical mapping, calculated by the correlation of the species composition and categories of indicators, revealed the zones of anthropogenic impact located on the shores of the lake, and the water of the lakes as weakly alkaline, quality classes 2–3. An increase in the number of cyanobacteria in coastal communities was revealed, which may be associated with an increase in the biogenic load on the lake ecosystems. The results of the analysis and mapping of indicators revealed that two major factors regulated phytoplankton: salinity and organic pollution. The sources of organic pollution are mostly associated with the intake of substances from the coastal zone, where resorts, roads, and settlements are located