Recruitment in the field of balanus improvisus and mytilus edulis in response to the antifouling cyclopeptides barettin and 8,9-dihydrobarettin from the marine sponge geodia barretti

Abstract

In this field investigation the two cyclopeptides, isolated from the marine sponge Geodia barretti Bowerbank (Geodiidae, Astrophorida), are shown to be very efficient in preventing recruitment of the barnacle Balanus improvisus (Cirripedia, Crustacea) and the blue mussel Mytilis edulis (Protobranchia, Lamellibranchia) when included in different marine paints. These brominated cyclopeptides, named barettin and 8,9-dihydrobarettin were incorporated in different non-toxic coatings. The substances were used in the concentrations 0.1 and 0.01% in all treatments. The most efficient paint was a SPC polymer. This paint, in combination with barettin and 8,9-dihydrobarettin, reduced the recruitment of B. improvisus by 89% (barettin, 0.1%) and by 67% (8,9-dihydrobarettin, 0.1%) as compared to control panels. For M. edulis, the reduction of recruitment was 81% with barettin (0.1%) and 72% with 8,9-dihydrobarettin (0.1%) included in the SPC paint. This indicates that the two compounds from G. barretti could provide non-toxic alternatives as additives in antifouling paints, since the heavy metal-based marine paints are to be replaced.

Keywords:

• field experiment
• Geodia barretti
• cyclopeptides
• Balanus improvisus
• Mytilus edulis
• non-toxic antifouling

Acknowledgements

This project is financed by the European Union through The European Regional Development Fund (ERDF), the MASTEC programme by the Swedish Foundation for Strategic Research, the Birger and Birgit Wåhlströms Memorial Fund and the C F Lundström Foundation. The authors are also grateful to Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning for financial support (marine environmental research).