LAUSR

Abstract The world’s freshwater ecosystems, sources of drinking water, are threatened by eutrophication. Many studies show that global warming leads to changes in aquatic ecosystems. Recently, eutrophication signs have been recorded in Lake Baikal, the world’s largest and deepest lake containing 20% of the world’s fresh water reserves. We have analysed long-term changes of the most sensitive natural factors (air and water temperature, wind regime, precipitation and solar radiation) and revealed their potential impact on emergence of unfavourable signs in the shallow zone of Lake Baikal. The main causes of adverse ecological processes are elevated temperatures of air and coastal water, reduced amount of precipitation, weakening of wind flows, and water exchange processes, and as a result, reduced self-purification. The highest number of anomalous climate changes has been recorded in the XXI century. Moreover, the years of the past decade were the most favourable for emergence of adverse processes in the lake (outbreak of rapid growth of algae and aquatic vegetation, rotting of their remains at the bottom and on the shores of the lake, etc.). Climatic factors will continue causing adverse effects in the shallow zone of Lake Baikal.