Benthic algal diversity and water quality evaluation by biological approach of Turnasuyu Creek, NE Turkey

Abstract

Turnasuyu Valley is one of the most important green valleys in the north of Anatolia. Located in this valley, Turnasuyu Creek is the major stream of the region. The community structure of benthic algae in Turnasuyu Creek was studied over a 1-year period between February 2017 and January 2018 from three stations. The epilithic algal flora and the dominancy of identified species were determined. A total of 174 taxa were identified from epilithic habitats. In the community of epilithic algae, members of Bacillariophyta were dominant (88 taxa, 51%) and Achnanthidium minutissimum (Kutzing) Czarnecki, Cymbella affinis Kutzing and Didymosphenia geminata (Lyngbye) Mart. Schmidt, Encyonema minutum (Hilse) D. G. Mann, Fragilaria capucina Desmazieres, F. crotonensis Kitton, Hannaea arcus (Ehrenberg) R. M. Patrick and Ulnaria ulna (Nitzsch) Compere have been the most frequent species found. In addition to diatoms, Pseudanabaena from Cyanobacteria, Oedogonium and Ulothrix from Chlorophyta and Spirogyra from Charophyta were the most frequent taxa in the algal flora. Assessment of physicochemical and biological data showed that the upstream region was oligosaprobic (clean) and the downstream region was oligo-ss-mesosaprobic (clean to slightly pollute). Slight pollution in the downstream zone may be due to anthropogenic pressures. The general trophic status of Turnasuyu Creek is considered oligo-mesotrophic.