Toxicity of Zinc to Aquatic Life in Tropical Freshwaters of Low Hardness

摘要

Zinc (Zn) is a metal of potential concern for a uranium mine whose receiving waters are in the World‐Heritagelisted Kakadu National Park in northern Australia. The chronic toxicity of Zn was assessed using seven tropical species inextremely soft freshwater from a creek upstream of the mine. Sensitivity to Zn was as follows (most sensitive to least sensitivebased on 10 effect concentrations EC10s): mussel Velesunio angasi > gastropod Amerianna cumingi > fish Mogurndamogurnda > cladoceran Moinodaphnia macleayi > green hydra Hydra viridissima > green alga Chlorella sp. > duckweedLemna aequinoctialis, with EC10s (<0.45 μm filtered fraction) ranging from 21 to 320 μg/L Zn and EC50s ranging from 52 to1867 μg/L Zn. These data were used to inform the risk assessment for the rehabilitation of the mine‐site and contribute to theglobal Zn dataset.