Growth and bleaching showed a dose
response to clove oil exposure, and the use of ethanol as a solvent had an additional deleterious effect, as also
suggested by observed changes in concentrations of eugenol following field application. Overall, growth was
reduced by 37.6% at the highest concentration (28% clove oil in seawater) relative to the control (0% clove oil).
The reduction in growth was nearly as great (35.3% of the control) at half the concentration of clove oil (14%)
when dissolved in ethanol. These results suggest the repeated use of clove oil (even without a solvent) can
deleteriously affect corals.