Composition and Productivity of Zooplankton as a Food Resource for Fish from Lake Dood Tsagaan (Darkhad Depression, Mongolia)

Abstract

The species composition, abundance, biomass, and productivity of zooplankton have been studied in different biotopes of Lake Dood Tsagaan in July 2022. Concerning to the qualitative composition, the lake community is characterized as cladoceran–copepod and almost equally represented by cladoceran and copepod crustaceans. Based on biomass data, dominant species have been identified in the nearshore and deepwater zones of the lake. The copepods Mixodiaptomus incrassatus (Sars), Arctodiaptomus paulseni (Sars), Arctodiaptomus anudarini Borutzky, Mesocyclops leuckarti (Claus), and Cyclops scutifer (Sars) were dominant in biomass in all biotopes of the lake. The mean zooplankton abundance in the lake was 86 300 ± 24 300 ind./m³ and biomass was 1463.7 ± 415 mg/m³. The qualitative and quantitative indicators of zooplankton have not significantly changed over the last 60 years. With respect to the quantitative characteristics of zooplankton, the trophic status of the lake can be considered as a-mesotrophic, with a medium food supply for planktophagous fishes.