Toxicity of Zinc Compounds to Aquatic Animals, with Special Reference to Fish

Abstract

The toxicity of zinc compounds to aquatic animals is modified by several environmental factors, particularly the hardness of the dilution water, the dissolved oxygen concentration, and temperature. The resistance of aquatic animals to zinc poisoning varies with species. It is modified by acclimatization, and possibly by age. Survival time is inversely proportional to concentration of zinc. For these reasons concentrations reported as lethal have varied widely. The mode of toxic action of zinc is uncertain. At acutely toxic concentrations it probably kills fish by destroying gill tissues. At chronically toxic levels it may induce stress resulting in death. The action of zinc undoubtedly differs at different concentrations, it varies with life history, and it is non-specific.