TOXIC EFFECTS OF FIVE TYPICAL WATER SAMPLES OF THE CHANGJIANG RIVER (YICHANG SECTION) ON RARE MINNOW (GOBIOCYPRIS RARUS) EMBRYOS

To investigate the toxic effects of fishery sewage, nature freshwater, industrial sewage, domestic sewage, and rural non-point water pollution along the Changjiang River (Yichang section), biological toxicity of the five typical water samples were analyzed. The detection of persistent toxic substances (PTS) in water samples revealed that the mean concentration of several heavy metal contents including Cu, Zn, As, Se, etc., in the industrial sewage sample and the conventional pollutants (ammonia nitrogen, COD, permanganate index etc.) in the domestic sewage sample were much higher than those of the international drinking water standards. The toxic effects of embryos showed that the embryos malformation (including spine curvature, pericardial edema, stunted growth, decreased heart rate and hatchability) and mortality in the industrial sewage or domestic sewage groups were significantly higher than those in other groups (P<0.05), indicating that industrial sewage and domestic sewage were more toxic than other water samples. The present study provided bio-toxicological evaluation of water samples in the Yichang section of the Changjiang River.