Determination of Chlorpyrifos toxicity in the freshwater amphipod Gammarus pulex (L.,1758)

In this study, it was aimed to determine the toxic effect of chlorpyrifos on freshwater amphipod Gammarus pulex (L., 1758). The samples of G. pulex (L., 1758), which constitute the living material of the study, were obtained from Munzur stream in Tunceli Province. G. pulex samples brought live to the laboratory were placed in aquariums prepared similar to their natural environment during the adaptation process. In order to determine LC50 values from acute toxicity tests, G. pulexes in aquariums with chlorpyrifos concentration determined in 24, 48, 72 and 96 hours periods were observed and the number of dead individuals was noted. Changes in MDA and GSH levels, and CAT, GSH-Px and GST enzyme activities were determined in order to determine the enzymatic and non-enzymatic effects of chlorpyrifos on G. pulex. As a result of the analysis, it was determined that the LC50 value was 0.140 ± 0.016 µg / L and that there were statistically significant (p<0.05) changes in the MDA and GSH levels and CAT, GSH-Px and GST activities of G. pulex individuals in the control group and chlorpyrifos applied research groups. As a result of the research, it has been determined that chlorpyrifos has a toxic effect on G. pulex, which is a fresh water amphipod, and low concentrations of chlorpyrifos cause the death of G. pulex.