Fertilisation of Acropora millepora gametes was 95.2‰0.9% in control assays containing unpainted polypropylene sheets (Fig. 3). In treatments where the plastic sheet was painted with antifoulant, the 6-mm-diameter circles of Cu-based paint inhibited fertilisation by at least 90%, with the TBT/Cu paint totally inhibiting fer-tilisation (100% inhibition) (Fig. 3). The smaller 2 mm circles of antifouling paint inhibited fertilisation by approximately 80% for each product.