Covering: up to June 2003Most benthic organisms produce planktonic larvae in their life cycles; larval settlement and metamorphosis are influenced by many environmental factors, especially chemical cues originating from conspecific adults, prey organisms, and substrates. On the other hand, larval settlement of other species endangers the survival of benthic organisms which therefore have antifouling defense. Marine natural products involved in biofouling and antifouling are described.