Phytoplankton structure and cyanobacteria specific composition of Foum-Gleita Lake, Mauritania

Abstract

In order to study the structure and the relative abundance of phytoplankton and the specific composition of cyanobacteria in the Foum-Gleita Lake, the surface waters of this Lake were subject of a regular monthly sampling extending over 12 months, from September 2017 to August 2018. Analysis of the phytoplankton by inverted microscopy method identified 28 taxa distributed over six phyla (Chlorophyta, Cyanobacteria, Bacillariophyta, Cryptophyta, Miozoa and Euglenozoa). However, analysis of the Cyanobacteria by same method showed that this phylum is specifically composed of eight genera (Microcystis, Gloeocapsa, Chroococcus, Dolichospermum, Oscillatoria, Planktothrix, Lyngbya, and Arthrospira), five of them are recognized as potentially toxic (Microcystis, Dolichospermum, Oscillatoria, Planktothrix and Lyngbya) and are mainly dominated by the species Microcystis aeruginosa and Dolichospermum flos-aquae during the hot season (May to September)