Seasonal variations in the epilithic diatoms of Koçan Falls (Erzincan, Turkey)

The present study explores some physical and chemical parameters in the epilithic diatoms in the water samples obtained from two stations in Koçan Falls, Erzincan from March to November 2014. Over the course of the study, 19 taxa of epilithic diatoms were recorded. Diatom genera which had the highest number of species in the study period were Cymbella (4 species), Navicula (4 species), and Cyclotella (3 species), while the most significant diatoms in terms of prevalence and the size of their populations were found to be Cyclotella spp., Gomphonema spp., Navicula spp., and Nitzschia spp. Over the course of the study, diatoms exhibited the highest level of growth in spring and summer, when there was more light and temperatures were higher. Considering the presence of diatoms within epilithic algae communities in all seasons, it appears that diatoms are cosmopolitan and can be among the algae that are commonly found at all types of substrata. The data obtained from the epilithic diatoms of Koçan Falls were analyzed according to Shannon-Weaver Diversity Index and Sorensen Similarity Index.