Phytoperiphyton of a Mineral Spring (Republic of Tyva, Russia)

This is the first report on the algae and hydrochemical composition of the Kholchuktug mineral spring, located in the Sut-Kholsky District of the Tuva Republic. According to the classification of therapeutic mineral waters based on temperature, it belongs to the cold group, and according to the degree of mineralization, it belongs to the low-mineralization group. The identified species composition of algae is represented by 72 species belonging to 35 genera and 21 families from 4 divisions: Cyanoprokaryota (5), Bacillariophyta (53), Chlorophyta (2), and Charophyta (11). Seven dominants were identified, of which Meridion circulare, Diatoma mesodon, and Ulnaria ulna stand out. The species composition is dominated by diatoms. An ecological and geographical analysis is conducted, according to which the spring is dominated by benthic species with a predominance of indifferent forms in relation to halobity and active environmental response; 56 species are identified in the studied water flow as indicators of water saprobity. The predominance of xenobionts, oligobionts, and betamesosaprobionts is noted. Geographically, cosmopolitan and boreal species are dominant.