Algal Chemical Defense Against Herbivores: Allocation of Phenolic Compounds in the Kelp Alaria marginata

Abstract

Higher concentrations of phenolic compounds were found in the reproductive fronds (sporophylls) of the intertidal kelp Alaria marginata than were found in the vegetative blades. The sporophylls were consumed by herbivorous snails at a lower rate than were the vegetative blades, in both field and laboratory studies. These results indicate that differential internal production of defensive compounds in a marine alga can significantly affect the pattern of herbivory on the plant.