Seasonal and spatial variation of epilithic algal community in Batlama Stream (Giresun, Turkey)

Abstract

Spatio-temporal changes in taxonomic composition and structure of epilithic algal community with some physicochemical features of the Batlama stream were assessed between June 2013 and May 2014 at the intertidal zone of the Batlama Stream, Giresun, Turkey. A total of 90 taxa were identified belonging to division of Bacillariophyta (80 taxa), Euglenophyta (3 taxa), Cyanobacteria (3 taxa) , Charophyta (2 taxa) and Chlorophyta (2 taxa) on epilitihic algae of Batlama Stream. Encyonema minutum, Ulnaria ulna, Cocconeis placentula, and Navicula cryptocephala species were the most abundant taxa among all samples of the four stations throughout the study. The Shannon diversity index (H’) values varied in the range from 0.5 to 1.2 and correlated with both species richness and relative species abundance (evenness). The results of the diversity analysis and the counting did not exactly match up with each other. Chlorophyll-a values of the stream and trophic classification (TDI, BDI) based on epilithic diatoms ascribed Batlama Stream to the mezotrophic range. Also, according to the calculated pollution index (PTI, S) values, all stations of the Batlama Stream were moderately polluted (β-mesosaprobity).