BENTHIC DIATOMS AS INDICATORS OF WATER QUALITY IN THE ACARLAR FLOODPLAIN FOREST (NORTHERN TURKEY)

Abstract

The structure and diversity of the epilithic and epiphytic diatom community and their relationship with the physicochemical parameters of the Acarlar Floodplain Forest were studied. Also, diatom indices and their applicability as a tool for estimating the floodplain water quality were tested. Diatoms were sampled monthly from February 2011 to January 2012 at three sites. A total of 94 taxa were identified. Approximately 76% of the diatom taxa are cosmopolitan distribution for Turkey. The diatom ecological indicator values, Trophic Diatom Index (TDI), Saprobic Index (SI), Swiss Diatom Index (DI-CH), the "Indice de polluo-sensibilite' spe'cifique", also named IPS and Trophic Diatom Index for Lakes (TDIL) were evaluated. TDI, SI and TDIL showed good relationships with environmental variables. A principal component analysis (PCA) was performed on environmental data. The results of PCA separated the second station with high specific conductance, hardness and NO3-N concentrations. It also showed that physicochemical parameters were affected by temperature and water level. Canonical Correspondence Analysis (CCA) was carried to determine the relationship between the diatom distributions and environmental variables. The results of CCA bi plot showed that specific conductance, hardness, turbidity, pH, dissolved oxygen, oxygen saturation and nutrients were significantly correlated with species distribution. According to the CCA result, two diatom groups were separated.