SUBLETHAL TOXICITY OF TRACE METALS TO LARVAE OF THE BLACKLIP ABALONE, HALIOTIS RUBRA.

The availability of literature regarding sublethal and chronic toxicity of heavy metals to early life stages of marine species is restricted to a few species of invertebrate mollusks. The early life stage of abalone, an important gastropod both environmentally and commercially, has been involved in limited research investigating the effects of heavy metal toxicity. Fertilized eggs of Haliotis rubra were exposed to a range of dissolved nominal concentrations of cadmium, copper, iron, lead, mercury, and zinc in individual solutions for 48 h. After 48 h of exposure, the test was completed by recording survival success and morphological abnormalities of veliger larvae in each heavy metal treatment. The mean 48-h median effective concentrations affecting normal morphological development of veliger larvae determined in this test shows a decreasing order of toxicity of copper (7 µg/L), mercury (21 µg/L), zinc (35 µg/L), iron (4,102 µg/L), cadmium (4,515 µg/L), and lead (5,111 µg/L). [ABSTRACT FROM AUTHOR]