Analysis of initial fouling process in coastal environment: Effects of settlement, attachment, and metamorphosis promoters

Effects of lumichrome, L-tryptophan, and curcumin on fouling organisms were examined on panels immersed in a near-shore aquatic environment. These pro ducts showed effective action in aquariums in preliminary screening tests f or promoting different steps of fouling. Lumichrome showed metamorphosis-in ducing activity for ascidian larvae (Halocynthia), L-tryptophan was a settl ement-inducer for larvae of barnacles (Balanus), and curcumin showed attach ment-promoting activity on the blue mussel (Mytilus). In order to establish that these tests are helpful in screening actual fouling or antifouling co mpounds, we examined the action of these three compounds in a coastal envir onment by following the first steps of biofouling, that is, by studying the quantity of chlorophyll, the number of bacterial cells, and the larvae set tled. These experiments on the seashore indicated that these compounds did not act as promoters for the target organisms; however, they did show promo ting effects on some nontarget organisms.