In this study, the epilithic diatoms were investigated monthly to reveal the water quality of Upper Porsuk Creek. The Samples were collected from three stations between December 2004 and August 2005. In this study, a total of 58 diatom taxa were found along the creek. The water quality of Upper Porsuk Creek was determined according to these taxa. Different diatom indices (SLA- Sládec83;k Index-, EPI-D-Eutrophication/Pollution Index, TDI-Trophic Diatom Index- and DESCY- Descy Index) were used in this study. There were significant differences among three stations with regard to diatom index values. Also, the diatom indices were compared with each other and it was found that the correlation coefficients between the indices were quite high.

In this study, the epilithic diatoms were investigated monthly to reveal the water quality of Upper Porsuk Creek. The Samples were collected from three stations between December 2004 and August 2005. In this study, a total of 58 diatom taxa were found along the creek. The water quality of Upper Porsuk Creek was determined according to these taxa. Different diatom indices (SLA- Sládec83;k Index-, EPI-D-Eutrophication/Pollution Index, TDI-Trophic Diatom Index- and DESCY- Descy Index) were used in this study. There were significant differences among three stations with regard to diatom index values. Also, the diatom indices were compared with each other and it was found that the correlation coefficients between the indices were quite high.