Surface characterisation of two gorgonian coral species: Implications for a natural antifouling defence

The natural, fouling‐resistant surfaces of the gorgonian octocorals Pseudopterogorgia americana (Gmelin) and Pseudopterogorgia acerosa (Pallas) were characterised utilising a variety of surface analysis techniques. Samples were collected in April and November 1987 from a natural population. No significant differences in bacterial surface populations were measured between species or between sampling periods. Contact angle analyses suggest that these natural surfaces have low surface energies (γ c=23–27 mN/m) that are in the range previously correlated with minimal bioadhesiveness. Gorgonians may utilise this minimal adhesiveness as a passive fouling‐resistance mechanism in conjunction with other antifouling defences.