Hydrobiological Assessment of the High Mountain Kolsay Lakes (Kungey Alatau, Southeastern Kazakhstan) Ecosystems in Climatic Gradient

Abstract

Aims: The aim of this study is to assess the ecological status of the Kolsay high mountain lakes according to their hydrochemical parameters and structure of phytoplankton communities and reveal the altitude climatic condition impact. Study Design: We implemented bio-indication and diverse statistical methods, which represent some new approaches in freshwater algal diversity analysis. Place and Duration of Study: Institute of Evolution, University of Haifa, Israel, Institute of Zoology, Ministry of Education and Science, Almaty, Kazakhstan, between August 2015 and April  2016. Methodology: We collected 20 samples of phytoplankton in August 2015 from four ultrafresh high mountain Kolsay lakes, located at the altitude of 1829-3170 meters above sea level in the Kungey Alatau, Southeastern Kazakhstan in gradients of climatic and environmental variables that we analyzed. Bio-indication and statistical methods for the ABC Method, Shannon-Weaver index, and WESI index (Water Ecosystem State Index) that indicated some toxic effect on photosynthesis of algae were used together with Statistica 12.0 and CANOCO Programs for calculating of relationships between environmental and algal communities data among the altitude of the lakes. Results: As a result, 28 species from five taxonomic divisions were identified in phytoplankton communities. According to hydrochemical indices, the lakes were classified as clean, with a slightly increased level of organic pollution in the Middle and Upper Kolsay. The ratio of species in the phytoplankton communities in all the lakes was corresponding to alkaline fresh non-flowing waters. Indication of the indicator species’ ratio, functional groups and size structure (the Abundance-Biomass-Comparison method, ABC) of phytoplankton showed that the level of organic pollution decreased in the high-altitude direction. The relationship between the graphic (ABC Method) and the calculation method (Shannon-Weaver index) used for the analysis of the phytoplankton structure is shown. Dynamics of saprobiological and dimensional parameters of phytoplankton links well with the distribution of the recreational load on the lake. The change of biomass of planktonic algae to a greater extent was determined by the dynamics of nitrogen compounds. In general, together with a low level of heavy metals in the water of lakes, the values of WESI index (Water Ecosystem State Index) indicated some toxic effect on photosynthesis of algae in the Lower, Middle Kolsay and the Lake Sary-Bulak. We revealed major variables that considered stimulating or stress factors with helps of statistical programs. Conclusion: Analysis of hydrochemical and biological data demonstrated that Kolsay mountain lakes are in the early stages of eutrophication. The processes of eutrophication are most evident in the Lower Kolsay. The changes in ecosystems of Kolsay mountain lakes can be caused by the growth of recreational load alongside the altitude related climate change.