RESUMEN
The middle Black sea region has quite large wetlands, including lakes, rivers, ponds, marshs and large reservoirs. Lake Cernek is one of the most valuable wetlands in Kizilirmak Delta. The lake and its environment have a high biodiversity due to species richness and natural habitats. Therefore, it has been recognized as a Ramsar site. The phytoplankton of lake Cemek consisted of 104 taxa belonging to Cyanobacteria, Bacillariophyta, Chlorophyta, Cryptophyta, Dinophyta, Euglenophyta and Xanthophyta divisions. Chlorophyta (46%) and Bacillariophyta (23%) members were dominant species. These were followed by Cyanobacteria (16%) and Euglenophyta (11%) members. Chlorella, Monoraphidium, Oocystis, Pediastrum and Scenedesmus from Chlorophyceae and also Anabaena, Chroococcus and Microcystis species from Cyanophyceae sometimes made water blooms. Blue green algae constituted algal communities in the surface of the lake in summer months. Algal community and its important species were grouped in terms of bray curtis similarity index, by taking into consideration the phytoplankton dynamics and months.