The influence of biofouling adhesion and biotic disturbance on the development of fouling communities on non-toxic surfaces

Field studies were designed to examine the effect of surface type (with respect to bioadhesion) and biotic disturbance (with respect to predation and grazing) on the percentage cover by biofouling communities and on barnacle adhesion strength. Non-toxic surfaces consisting of epoxy, Teflon(TM) and silicone were chosen to represent surfaces with high, medium, and low bioadhesion. Substrata were compared in a fully crossed experimental design; samples in fully caged treatments assessed biotic disturbance effects, those in partial cages assessed cage effects and uncaged panels acted as controls. The caged panels for all the surface types developed the greatest fouling cover and had the highest diversity of organisms. The number of taxa and survivorship were reduced on partially caged and uncaged panels. The uncaged and partially caged silicone surfaces remained almost free of fouling. The mean barnacle adhesion strengths for the caged treatments of epoxy and Teflon(TM) were less than their uncaged and partially caged equivalents. This may be a consequence of biological disturbance. The results have important implications for the interpretation of the performance of non-toxic foul-release coatings.