Inhibitory effect of Indian sponge extracts on bacterial strains and larval settlement of the barnacle, Balanus amphitrite

The total ban imposed on TBT based antifouling paints, since 2008, has triggered the search for Natural Product Antifoulants (NPAs) as a promising alternative for the development of environmentally benign coatings. In view of this, thirty six species of sponges collected from the Gulf of Mannar, India, were screened for their inhibitory effect on fouling bacterial strains and cyprids of Balanus amphitrite. Of these, Fasciospongia cavernosa and Petrosia nigricans had high activity against the fouling bacteria and Iotrochota baculifera significantly inhibited larval settlement. Oceanapia fistulosa, Haliclona exigua and Haliclona cribricutis exhibited considerable activity against both bacterial strains as well as barnacle larvae. These observations indicate high prospects for isolation of effective NPAs from Indian sponges.