Water quality assessment of the DTD canal system by diatom indices

Abstract

The main objective of this paper is to evaluate the water quality based on diatom indices in the study area of the Danube–Tisa–Danube (DTD) canal system. We used four diatom indices: Watanabe’s index (DAIpo), biological diatom index (BDI or IBD), the trophic diatom index (TDI) and index of pollution sensitivity (IPS). Benthic samples were collected in the spring and autumn 2002 and 2003 from nine sampling sites. The standard method with concentrated sulfuric acid was used for treatment of the algological samples [Krammer and Lange-Bertalot 1986] and then permanent slides of diatoms were made. The abundance was estimated by counting 400 valves of each taxa present on slide [Round 1991, 1993]. Investigation of the DTD canal system resulted in description of 145 diatom taxa. Based on the indicator values of identified taxa we calculated four diatom indices (DAIpo, BDI, TDI and IPS) and estimated water quality in the study area of the DTD canal system.