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.