Bioassessing ecological status of surface waters in the Araban-Yavuzeli catchment (Turkey): application of diatom indices

Abstract

Within the scope of the European Union Water Framework Directive, diatom assemblages as biological quality components were used to evaluate the ecological status of 12 surface waters in the Araban-Yavuzeli catchment between October 2013 and October 2014. A total of 75 diatom species were identified during the study period. Amphora ovalis, Denticula elegans, Gomphonema parvulum,Gomphonema truncatum, and Navicula cryptocephala were commonly observed. The relationship between diatom assemblages and environmental factors was assessed by canonical correspondence analysis and weighted average regression. Dissolved oxygen, tem-perature, nitrate, biological oxygen demand, lead, and copper played significant roles in the distribution and composition of diatom assemblages (P