Changes in photosynthetic pigments and species diversity of epiphytic diatoms on Myriophyllum triphyllum exposed to cadmium

Abstract

With the aim to investigate alterations in diatom population when exposed to cadmium under epiphytic conditions, an experiment was conducted on samples from Myriophyllum triphyllum without removing the epiphytic diatoms. Epiphytic diatoms were exposed to cadmium in doses of 0, 2, 4, 6, 8, and 16 ppm for 96 h. While the total organism showed a decrease in all cadmium concentrations compared to the control group, the viability rate in the total organism declined from 87% to 62%. Gomphonema, Navicula, and Nitzchia were found to be the dominant species in the flora. The diversity index value, which was determined to be 1.18 in the control group, dropped to 0.51 as a result of the increase in cadmium concentrations (16 ppm). The amounts of chlorophyll-a and carotenoids decreased with increasing cadmium concentrations.