Interannual Fluctuations of Zooplankton in the Tayshir Reservoir (West Mongolia)

Abstract

An increase in electroconductivity in the reservoir created in the upper part of alpine Dzabkhan River leads to the elevation of the zooplankton abundance and biomass determined by crustaceans. The lowest values of quantitative indicators are characteristic of the zooplankton in the littoral zone of the reservoir. This relates to the flooding of land areas characterized by poor soils and terrestrial vegetation, as well as by wave mixing. It is revealed that, with an increase in water level and reservoir volume, the quantitative characteristics of coastal zooplankton in all parts of the reservoir increase; in the channel zone, this happens only in the upstream and midstream parts. On the contrary, in the near-dam area, these indices decrease.