Diversity and ecology of diatoms from Felent creek (Sakarya river basin), Turkey

Diatoms are an important group of aquatic ecosystems. To date, there have been many important algological studies in different river basins in Turkey. However, the use of diatoms in biomonitoring (according to diatom indices, Watanabe's or Van Dam's systems) is relatively new in Turkey. In the present study, 41 samples of epilithic diatoms were collected from 5 stations along Felent creek between June 2006 and February 2007 and a total of 117 diatom taxa were identified. The bio-indication (autoecology and abundance scores in the communities) of Felent creek was investigated and, as a result, the organic pollution indicators of Watanabe's classification (81 species, 69.2%) constituted 3 groups. The Sladec ̌ek's index calculated for eachsampling station varied from 1.36 to 2.08 (from oligo- to betamesosaprobic) at stations, and the river pollution index was calculated for eachdefined environmental variable as well as for species richness and index of saprobity over stations in summer and winter. The river water was alkaline and temperate withlow salinity, and there was organic pollution in summer. Species richness was mostly higher in winter than in summer.