Impact of runoff water from an experimental agricultural field applied with Vertimec® 18EC (abamectin) on the survival, growth and gill morphology of zebrafish juveniles

Edge-of-field waterbodies in tropical agroecosystems have been reported to be especially prone to pesticide contamination through runoff resulting from intensive irrigation practices and tropical rainfall. In the present study, the effects of runoff from an experimental agricultural field applied with Vertimec® 18EC (active ingredient: abamectin) on zebrafish were evaluated. To this end, the experimental field was applied with the Vertimec® 18EC dose recommended for strawberry crop in Brazil, whereas another field was treated with water only to serve as control. No effects of runoff water from either plot were recorded on survival. Water from the treated field led to increased growth and gill alterations. In general, these alterations were of the first and second degree, including proliferation of cells between the secondary lamellae, dilation at the lamellar apex, detachment of the respiratory epithelium and aneurism. These results confirm the high toxic potential of Vertimec® 18EC and provide evidence that environmental risks are likely to occur in areas subject to runoff containing this pesticide.