Methane in water and bottom sediments of lake Baikal

Abstract

The results of the methane concentration distribution in different areas of Lake Baikal obtained in 2014 and 2015 were analyzed in this study. In periods of expedition examinations, the methane concentration in the water and in the bottom sediments of the lake varied in a range from <0.1 to 13.9 μl/dm3 (average: 0.7 μl/dm3) and from <0.01 to 3.69 μg/g of the dry deposition (average: 0.34 μg/g). The maximum methane concentrations in the water and bottom sediments in the lake were typical for the North region, where rivers Verkhnyaya Angara and Kichera are flowing, and in the individual stations of the profile set along the mouth area of the river Selenga, as well as the stations located in the zone of the waste water underwater release of Baikalsk City and the Baikalsk pulp and paper mill closed in 2013. The presence of increased and decreased methane concentrations in the examined top strata of the sediments of Lake Baikal was stipulated herein aside from the differences in the power of the anthropogenic effect by the variation of the sediment accumulation conditions determining the particle size distribution and the organic matter content and, as a result, by the methanogenesis intensity.