Algal flora Saint-Petersburg water bodies

In the spring and summer of 2019, 43 lakes and ponds of Saint Petersburg were surveyed. The algal flora contains 110 species of algae of the following divisions: Cyanophyta =Cyanobacteria=Cyanoprokaryota – 18, Cryptophyta – 1, Dinophyta – 9, Euglenophyta – 11, Chlorophyta – 57 Streptophyta - 2, Ochrophyta (classes Chrysophyceae – 2, Bacillariophyceae – 10). For the majority of the found species, the saprobity mark and saprobic index were specified. The most diverse group in the water bodies of Saint Petersburg is green algae, which includes single and coenobial algae of the coccoid and monad tallom organization, which are well adapted to vegetation in the water column. In most reservoirs at spring Monoraphidium arcuatum (Korshikov) Hindák and Monoraphidium contortum (Thuret) Komárkova-Legnerova, species of genera Scenedesmus, including species of the genera Desmodesmus and Tetradesmus actively vegetate. In the reservoirs of Saint Petersburg, the leading positions are taken by euglenic algae, especially species of genera Trachelomonas (Trachelomonas hispida (Perty) F. Stein, Trachelomonas volvocina (Ehrenberg) Ehrenberg). Summer phytoplankton differs in the more vigorous development of blue-green algae-especially such species as Dolichospermum flosaquae (Brébisson ex Bornet & Flahault) P. Wacklin, L. Hoffmann & Komárek, Dolichospermum spiroides (Klebhan) Wacklin, L. Hoffmann & Komárek. The species of β- mesosaprobic dominate. There are also α-mesosaprobes and species with a wide range of existence in reservoirs with different degrees of organic content. Biological analysis of the surveyed water bodies shows that their condition is satisfactory.