New and rare for the Omsk Priirtyschie species of algae from the reservoirs of Omsk

UDC 528.26/27:502.51(571.13)

Abstract

Studying the biocenoses of urban reservoirs can signifi cantly expand the understanding of the biodiversityof specially protected natural territories located within the city. In 2024, the phytoplankton of reservoirs of theStarozagorodny natural recreational complex of regional importance, located in the center of Omsk, was studied for thefi rst time. Two artifi cial fl owing reservoirs (small and large) have the established nature protection regime, the main taskof which is to regulate anthropogenic load. Th e study determined the taxonomic composition, abundance and biomassof phytoplankton, and established the trophic status of water bodies. Th ree new species and intraspecifi c taxa of algaefrom the Chlorophyta (1 BBT) and Charophyta (2 BBT) divisions have been identifi ed in the phytoplankton of reservoirs.Information is also provided on green and desmidium algae found in reservoirs rare for the IWT region. Micrographs ofnew and rare species are presented, as well as a brief description with instructions. In terms of biomass, the trophic statusof the large reservoir corresponded to the eutrophic category of waters, and that of the small reservoir corresponded to themesotrophic category. Th e conducted studies allowed us to supplement the taxonomic list of algae and cyanobacteria ofthe Omsk Irtysh region, which currently includes 1166 IWT.