Lake Issyk-Kul: Its History and Present State

Abstract

Lake Issyk-Kul in Kyrgyzstan is one of the deepest and largest mountain lakes of the world. The closed-basin lake is slightly brackish and waters are dominated by sodium, and chlorite and sulphate. Although large tourism resorts and many camps without appropriate sanitary facilities were established on Lake Issyk-Kul’s shores after the Soviet era, the lake is still oligotrophic with high concentrations of dissolved oxygen down to its great depths. The large volume of the lake in comparison to surface and groundwater inflows inhibited major reductions of the water quality in the central and deep part of the lake so far. However, decreasing lake levels since the beginning of systematic observations in the year 1927, contamination of littoral waters due to inefficient or lacking wastewater treatment, and the influx of fertilizers and pesticides from farmlands on the lakeshore plain are major concerns for sustaining the fragile ecosystem of Lake Issyk-Kul during times of ongoing global warming and economic development in the region.