Epilithic Diatomes and Seasonal Changes in Yedisu Dam Lake (Bingöl)

Abstract

A total of 74 taxa belonging to epilithic diatoms were identified in rock samples collected seasonally from the Yedisu dam lake HES within the borders of Bingöl province between March and December 2022. Among the diatoms (Bacillariophyta), 4 taxa belonging to centric diatoms and 70 taxa belonging to pennate diatoms were recorded. Cyclotella meneghiniana and Meridion circulare were identified among the centric diatoms; Achnanthidium minutissimum, Amphora ovalis, Cymbella affinis, Fragilariforma bicapitata, Gomphonema olivaceum, Gomphonema parvulum, Hantzschia amphioxys, Nitzschia dissipata, and Nitzschia palea were identified among the pennate diatoms. Ulnaria acus, and Ulnaria ulna were more remarkable than other diatoms in terms of both their seasonal occurrence and individual counts. The season with the highest recorded individual counts of diatoms was spring and summer, when nutrient salts increased. The number of individuals recorded for Achnanthidium minutissimum in spring (120 cells/ml) was the highest number recorded during the study period, while the numbers recorded for Hantzschia amphioxys (78 cells/ml) and Amphora ovalis (72 cells/ml) in autumn were the second highest Surirella tenera was  notable for being recorded only in spring. Among epilithic diatoms, the genus Nitzschia was recorded with the highest number of species (9 taxa), followed by Cymbella with 7 species and Gomphonema and Navicula with 6 species each.