Vertical Distribution of Methane in Baikal Water

Data on the vertical distribution of dissolved methane in Baikal water column are analyzed. The zone of open lake now shows an increase in the concentrations of dissolved methane compared with 2002–2004. The possible causes of this phenomena are considered. Methane concentration in the aerobic water column of Baikal decreases from the surface toward the bottom. The active layer of the lake, as well as that in the ocean, contains a peak of methane concentration. In the main, deep part of the water column, methane concentration is lower than that equilibrium with the atmosphere because of the activity of aerobic methanotrophic microflora. The standard procedure of the static headspace analysis for determining methane is supplemented by measuring the pressure in a closed system. The concentrations of methane determined by methods of vacuum extraction and static headspace analysis are compared.