The influence of clomazone-based herbicide formulation on common carp (Cyprinus carpio) – a laboratory study including pathophysiological and histopathological assessment

Herbicides are widely applied in agriculture, which results in the pollution of ecosystems, including inland waters. Herbicides present in water may cause pathological changes in fish. The aim of this study was to evaluate the effects of a clomazone-based herbicide formulation, Command 480 EC, on the haematological and blood biochemical parameters of common carp as well as the microstructure of selected organs: gills, liver and trunk kidney. The fish were exposed to Command 480 EC at a concentration corresponding to 1 or 5 mg/l of clomazone (groups COM1 and COM2, respectively) for 10 days. The conducted analyses showed that the treatment caused numerous changes in red blood cell parameters, no significant changes in WBC count (in comparison to the control), and only a few transient changes in the leukogram. The only significant change in the biochemical parameters in comparison to the control was a decrease in the triglyceride concentration in fish observed after 3 days (group COM1) and 10 days (group COM2) of exposure to this herbicide. No considerable histopathological alterations were observed. The results of the present study suggest that exposure to the applied clomazone-based formulation can cause pathophysiological changes in common carp. It was also observed that blood parameters (especially haematological ones) are more sensitive markers of exposure to Command than the microstructure of the tested organs.