An investigation on phytoplankton of Gelevera stream and its seasonal variation (Espiye-Giresun)

Algal flora of Gelevera Stream and its seasonal variation and some physical and chemical factors effecting the seasonal variation were investigated between May 2012 and May 2013. A total of 103 taxa were identified belonging to the divisio of Bacillariophyta, Charophyta, Chlorophyta, Cyanobacteria, Euglenozoa, Miozoa in the phytoplankton of Gelevera Stream. Shannon-Weaver diversity and evenness were used to determine phytoplankton diversity. Community structure was defined by Cluster analysis in the Gelevera Stream. Moreover, phytoplankton functional groups of the Gelevera Stream were determined by evaluating ecological conditions. In the Gelevera Stream 8 functional groups (D, P, TC, TB, F, L0, X1 ve MP) were determined. D, P and TB groups of species were found to be commonly found. While Shannon Diversity Index value varied between 0.60 (November 2012) and 1.21 (September 2012), the lowest evenness value 0.58 was calculated in November 2012, the gihest evenness value 0.97 was calculated in July 2012. The results of Cluster analysis supported the detected findings in the Gelevera Stream. Chlorophyll a showed a parallel development with phytoplankton diversity.Total organism numbers in the phytoplankton floradecreased in the months of increased rainfall in the Gelevera Stream.