Fecal stanoles in sediments of Lake Shira (Siberia, Russia) as a proxy of human impact on surrounding territory in the Late Holocene

Abstract

The analysis of biochemical markers of fecal intake is one of the newest trend in paleolimnology. Stanols (cholestanol, stigmastanol, etc.) produced by the intestinal microflora from sterols are indicators of fecal influx into a water body. Coprostanol is synthesized in the human intestine, therefore, the presence of coprostanolin bottom sediments can be used to reconstruct the dynamics of the population in the lake watershed and to evaluate the dynamics of fecal pollution. Using the gas chromatography method, we were the first to estimate the content of cholestanol and coprostanol in the dated core layers of the bottom sediments of Lake Shira. The raised proportion of coprostanol indicates an increase in fecal anthropogenic inflows into the lake in the modern period, as well as in earlier periods of the history of Khakassia, in particularly during the existence of the Yenisei Kyrgyz state (VIII - XIII centuries CE).