Increasing awareness of the deleterious effects of toxic components in antifouling coatings has raised interest in the potential for nontoxic alternatives. This book examines how marine organisms from bacteria to invertebrates and plants use chemicals to communicate and defend themselves. Chemicals that prevent colonisation of living surfaces are particularly pertinent to antifouling technology and may inspire new solutions. The challenge is to identify such compounds, identify the means for sustainable production and incorporate them into coatings to give long-term antifouling efficacy.