Abstract: Fouling of marine structures such as boats by shell bearing sea animals which attach themselves to such structures, such as barnacles, is inhibited by coatings containing lipid soluble, non-toxic, biodegradable substances which prevent the animals from sitting down on the structures. These substances attack the nervous system of the barnacle, neutralize the glue extruded by the barnacle, and otherwise prevent the barnacles from attaching themselves to surfaces immersed in the aqueous marine environment while being benign to the environment. A preferred inhibitor is pepper containing capsaicin. The inhibitor is incorporated into standard marine paints, impregnants, varnishes and the like.