No abstract

Lake Kulundinskoye (Kulunda) has been experiencing a downward trend in water salinity over the past three years (from 2017 to 2020) due to an increase in the overall level of moisture in the Altai Territory. In connection with this decrease, the authors observe changes in the composition of the zooplankton in the hypersaline water reservoir. The biota is replenished with brackish-water hydrobionts and the density of various aged individuals of Artemia crustacean and its cysts decreases under conditions of low water salinity.

The results of ecological monitoring of the hypergaline lake Kulundinskoye of the Altai Territory in the period 2021-2022 are presented. The research was carried out in the form of a comprehensive study of abiotic factors of the reservoir (climatic features of the lake, temperature regime, salinity of water), biological factors (species composition of brackish-water zooplankton, its abundance), production and structural indicators of the gill-legged crustacean Artemia Leach, 1819. Desalination of water during the transgressive period of water content caused successional speciation processes. There was a change of the gill-legged crustacean as a dominant and monovid to a complex of brackish-water fauna. The artemia population developed under the influence of unfavorable salinity of water with a fluctuation in the lake from 1.9 (April) to 99.0 mg/dm3. The influence of the transgressive phase of water content on the biota and the extraction (catch) of a biological resource - artemia (at the stage of cysts), as well as the importance of the formation of their commercial accumulations of abiotic environmental factors, is shown. Studies have shown that the prevailing combination of factors during the transgression period – tense climatic conditions, low salinity of water (less than 100 mg/dm3), low number of artemia crustaceans, was the absence of commercial accumulations of biological resources.

Long-term data (2002–2019) on the conditions of the formation of Artemia populations in different types of hyperhaline lakes of the Altai Territory are analyzed. The boundaries of individual fecundity and average fecundity were calculated, the influence of abiotic factors on the quality content of ovisak was shown. The peculiarities of their changes at different levels of water salinity during the growing season have been investigated. The average number of litters (clutches) for Altai populations was calculated, the influence of environmental factors on this indicator was analyzed.