The number of artemia bottom cysts (Artemia Leach, 1819) in different hyperhaline lakes of the Altai territory

Artemia cysts are economically significant. One of the components of the reserve is the biomass of artemia cysts submerged to the bottom. 22 hyperhaline lakes of the Altai Territory were studied in 2018–2021. It was found that artemia lived in all the studied lakes, including bisexual populations in 4 lakes, and parthenogenetic populations in 18. The lakes were conditionally divided into 5 groups. 1192 soil samples were selected and processed. The types of sediments were conditionally divided into 6 groups depending on the dominant particles. The dependence of the concentration of bottom artemia cysts on the type of sediments was revealed (r = 0.289, p = 0.001, n = 732). It is determined that the concentration of cysts does not depend on the salinity of the water in the lake, with the same salinity, the density of cysts varies from 0 to several million depending on the type of sediments. The dependence of the concentration of bottom cysts in the summer period on the selected group of lakes was established (r = 0.817, p = 0.1, n = 5). In brine lakes the minimum concentration was observed in spring, in Deep-water and Medium-deep lakes the maximum was observed in summer, in Shallow brine lakes — in autumn. In group of lakes “Shallow, salt precipitates“ and “Drying up in summer” lakes a decrease in the concentration of cysts at the bottom was noted from spring to autumn. The influence of the depth of occurrence on the density of artemia cysts in silt sediments has been studied: in Maloe Yarovoye Lake 63% is in the upper layer, in Kulundinskoye Lake the highest density is in a layer of 5–10 cm, in Bolshoe Yarovoye Lake cysts are evenly distributed in viscous silt at a depth of 5 to 20 cm. The change in the concentration of bottom cysts in autumn and subsequent spring was analyzed to identify the proportion of cysts that have risen from the bottom. Up to 98% of cysts float in Shallow lakes, 4–62% in Deep and Medium-deep lakes.