Cadmium effects on total individual numbers, species diversity and pigments content of epiphytic diatoms growing on Myriophyllum spicatum L.

This study investigated the total organism change, species richness, chlorophyll-a and carotenoid changes in the floral composition, which are developed by epiphytic diatom species growing on Myriophyllum spicatum L., collected from the Gokpinar Lake (Sivas), against the effects of cadmium. The concentrations of the cadmium (0, 2, 4, 6, 8, and 16 mg/L) were used and they were exposed to heavy metal for 96 hours. The experimental set up was already assembled before the epiphytic diatoms separated from the M. spicatum. While the total organism decreased in all cadmium concentrations compared to the control group, the viability rate within the total organism decreased from 90 to %60. Cocconeis placentula var. euglypta (Ehr.) Grun. and Gomphonema minutum Ag. were found to be dominant species in the flora. The index of diversity was determined as 0.82 in the control group. Depending on the increase in cadmium concentration, this value decreased to 0.38. Chlorophyll-a and carotenoid quantities decreased with the increase of cadmium concentration.