The use of geochemical monitoring to assess the environmental impact on the ecosystem of Lake Baikal (Russia)

Abstract

Abstract Currently, many countries of the world experience drinking water scarcity. In this aspect, Russia has an advantageous position, having on its territory Lake Baikal, the largest storage of fresh water. UNESCO declared Lake Baikal as a World Heritage Site whose state scientists from Russia and other countries monitor and study. An analysis of the literature and the author information about the Baikal aquatic ecosystem has shown 70-year invariability of macroelement water composition of Lake Baikal and its only outflow, the Angara River. The water of Baikal and the Angara River has a constant calcium bicarbonate composition and is saturated with oxygen, 10-14 mg/l or rarely more. The average mineralization of water in Baikal and the Angara source for the study period (1950-2018 and 1997-2018) is 95-97 (87-112) mg/l. The analysis of the 13-year (2006-2018) data on the trace element concentration in the Angara source has revealed a complex pattern of changes in concentrations of some elements. The time trends of the concentrations for the bulk of elements sometimes indicate abnormal (minimum-maximum) concentrations regardless of the season. This can be only due to “one-time or instantaneous” natural or anthropogenic changes in the Baikal environment. The Baikal tributaries indicate different chemical composition, which can be due to not only drainage of rocks with different content but also the anthropogenic impact. A simultaneous testing of water (during a month) has shown that some macro- and trace elements (F-, HCO3 - and SO4 2-, as well as Li, Mo, B, U, Fe, etc.) have at the same time the similar concentrations in the water from Baikal, the Angara source and most tributaries.