Abstract
The effects of thermal waste water to the epilithicdiatom species composition were examined. The dominant species found at abnormal water temperaturestation wereAchnanthes exigua, Navicula minima, Navicula sp., Gomphonema clevei, Gomphonemaparvulum, Nitzschia amphibiaandNitzschia frustulum. Most of the dominant species were eurythermalor thermophilous ones. The diversity of the communities did not lowered remarkably.
