The toxicity of the dispersed oil continued to increase
with exposure period up to 96 hours. Additionally, the
larvae in the higher concentrations of dispersed oil
completely dissolved in the treatment solution. The
toxicity of dispersed oil to coral larvae is consistent with
the results of experiments on other aspects of sexual
reproduction in reef corals. Fertilization in Acropora
tenuis was completely blocked following exposure of
gametes to dispersed oil at hydrocarbon concentrations of
only 0.15 ppm (Harrison 1999), and EC50 values for
fertilization success for A. valida, A. millepora and
Platygyra sinensis ranged from 0.1 – 1.8 ppm (Harrison
and Lane unpub. data).