Mass vegetation of Schroederia setigera (Schroder) Lemmermann in the salty lake Raynfeld (Omsk region)

The first information on the species composition, abundance and dominance of algae in the plankton of the salt lake Raynfeld (Omsk region) in August 2013 is given. The purpose of this article is to determine the species composition and abundance of phytoplankton in the lake Raynfeld, identify the features of algae dominance. Quantitative samples of phytoplankton in a volume of 0.5 liter were selected by scooping from the water surface, fixed with 40 % formalin, and concentrated by settling method. At the same time, hydrochemical analysis was carried out and the transparency and temperature of the water were measured. The total dissolved solids of water was 28 g/dm3, the water temperature reached 21 °C, the transparency - to the bottom. Samples were processed by conventional methods. The number of algal cells was counted in the Goryaev chamber on a microscope “Mikmed-1”. At the same time, the sizes of the species cells were measured. Phytoplankton biomass was calculated by the conventional method by cell volumes. Photographs of algae were obtained with a camera on a light microscope “Euler Professor 770T”. Species composition of summer phytoplankton of the lake Raynfeld differs scarcity, therein identified 9 algae taxa of four divisions, including: Cyanobacteria - 4, Cryptophyta - 1, Bacillariophyta - 3, Chlorophyta - 1. Status of phytoplankton development reached the initial stage “water blooming” and average biomass in the lake (4.12 ± 1.14 g/m3) corresponded to the eutrophic water category. For the first time for water bodies of Omsk Priirtyshie in the lake Raynfeld recorded massive vegetation (blooming) of Schroederia setigera (Chlorophyta, Chlorophyceae). Morphological characters and sizes of the species correspond to the description in indexes. Similar cases of the mass vegetation of the Schroederia setigera in salt lakes of Russia were not observed before.