Summary
Larvae and spat of the Pacific oyster Crassostrea gigas (Thunberg) were subjected to a series of concentrations of cadmium, added as cadmium chloride, in sea water. Exposure of 5-day-old larvae to 20 μg/ℓ for a period of 7 days resulted in increased mortality and a 20% reduction in size. Prolonged exposure (12 days) of 41-day-old spat to the same concentration resulted in a 40% reduction of spat growth. Greater mortality and suppression of growth were evident at higher cadmium concentrations and cadmium-treated spat did not recover rapidly when transferred to control solutions. The numbers of larvae settling in the presence of 50 μ/ℓ and their viability were significantly lower than for larvae settling under control conditions.