Influence of Climatic Factors on Interannual and Seasonal Dynamics of the Environmental State of the Salt Lake Adzhi-Baichi (Crimea).

The ecological state of inland waterbodies, including hyperhaline lakes, is determined by the combined influence of natural and anthropogenic factors. For the purpose of holding interannual and seasonal monitoring of the hypersaline lake Adzhi-Baichi, located on the western coast of the Crimean peninsula in the arid climate zone, we studied the change in air and water temperatures, as well as the hydrochemical parameters of brine and the dynamics of the Artemia population Artemia salina in 2017–2020. The established general trends are expressed in an increase in air and water temperature in the summer period with maximum values in July–September (above +30°С), which was accompanied by an increase in reservoir salinity and a decrease in the oxygen content. Fluctuations in the pH and values of the redox potential Eh were less pronounced. The maximum brine salinity (more than 350‰) was noted in 2017, the minimum oxygen content (0.7–1.0 mg/L) occurred in 2020, and the lowest Eh values (–78.5 mV) were found in 2019. Crustacean cysts were found in all of the studied periods during the year. Nauplii appeared in March–April at a water temperature of +3...+7°C; adults were found in the summer months and at the beginning of autumn. In summer, at high water temperature and salinity but a low oxygen content, a crustacean die-off occurred. The results reflect the characteristics of the influence of climatic and anthropogenic factors on the ecosystem of the hypersaline lake and can serve as a model for the prediction of possible scenarios of the impact of climate change on inland waterbodies and can be useful for an understanding of the processes of transformation of aquatic ecosystems in arid zones located in a region of intense anthropogenic influence, as well as the development of measures for their protection and the rational use of resources. [ABSTRACT FROM AUTHOR]