Gaziantep (Türkiye) Şahinbey'deki sucul ekosistemlerin diyatome indeksleri kullanarak değerlendirilmesi

Diatom is one of the five biological quality elements as ecological indicator recommended by the EU Water Framework Directive for the assessment of ecological status running waters. This study designed to assess ecological quality of freshwater bodies in the Şahinbey of Gaziantep (Turkey) using the trophic index Turkey (TIT) and evaluate the ecological preferences of the diatom assemblages by multivariate approaches. Canonical correspondence analysis (CCA) was used to relate diatom assemblages with the environmental variables to explore their relationships. Weighted averaging regression was used to estimate diatom species optima and tolerance levels for the environmental variables. At Kıratlı Stream, the highest mean value of PO4 was 76.6 µg/L, whereas the lowest mean value was 58.1 µg/L at stations of Zülfikar Reservoir. Environmental variables seasonally changed in these ecosystems. According to the Monte Carlo permutation test results, the relationship between diatom assemblages and environmental variables was found 91.6% Most effective explanatory factors (e.g., DO, water temperature, NO3, Pb2+, etc.) played the significant role (p=0.006) in the seasonality of species. Some diatom species such as Amphora ovalis, Cymbella excisa, Cocconeis placentula, Gomphonema parvulum, Fragilaria capucina, and Ulnaria ulna were found during study period, supported by CCA. TIT values ranged between 1.71 in Burç Reservoir and 3.09 in Yeniyazı Creek. TIT as a valuable indicator of ecological status could be a useful tool for assessing ecological status water bodies in Gaziantep. Key words: Assessment, CCA, Diatoms, TIT, Water bodies, Gaziantep