Use Alga Ankistrodesmus falcatus (Corda)Ralfs as Bioindicator to evaluated the level of Impact of Exposure to Pesticides on Green Algae in aquatic system

Abstract

In the current study the cells of pure culture media of alga Ankistrodesmus falcatus was used as a bioindicator in monitoring and follow-up to the expected bio-effects in biomass of green algae in the aqueous medium when exposed to different concentrations of organic phosphorus pesticide known commercially (Chemogos). Five concentrations of Chemogos (1, 2, 3, 4,and 5 mg/l) were introduced as an environmental contaminant in cells culture medium of algae for 24,48,72,96 and 120 hour, under laboratory conditions controlled by a temperature of 26 ±2 Cº, 380µ E/m, with photicsystem 16: 8 hour light: dark. Bio and toxic effect criteria of the pesticide in algae biomass, growth rate and absorbance value has been applied through estimated the rate of inhibition and then estimate the average of effective concentration EC50. The results showed that all of examined concentrations specially 2,3,4,5ppm of pesticide have a clear effect on growth rate and absorbance value; It scored the fewest total of cells number and intensity of absorbency (1.400 × 106 cell/ml and 0.032 nm) When the transaction is focusing 5ppm after 120 of the treatment time, compared with the control sample which recorded (3.049 × 106 cell/ml and 0.116 nm) respectively, and the results also obtained that this pesticide have a great toxic effect for cells of studied alga, as was the arrangement EC50 values (2.71, 3.07,4.91,4.93,5.72) mg/l after treatment during 24,48,72,96,120 hours of treatment time.