Reversible effect of potassium sorbate on Balanus amphitrite larvae. Potential use as antifoulant

Abstract

Marine biofouling constitutes a major worldwide technical and economic problem. International regulations concerning the protection of both the environment and industrial workers have prompted paint manufacturers and end users to look for suitable replacements for traditional antifouling (AF) pigments. For this reason, the potential AF activity of potassium sorbate (KS) on nauplii and cyprids of Balanus amphitrite was tested in laboratory and field trials. Larval bioassays demonstrated a marked inhibitory and reversible effect. The values obtained for EC₅₀ and LC₅₀ were 9.91 mM and 36.73 mM, respectively, and the therapeutic ratio was 3.71, indicating that KS acts via a non-toxic mechanism. After 60 days in the sea, a varnish coating incorporating KS showed a substantial decrease in micro- and macrofouling density and diversity. This investigation indicated that KS is a promising AF agent for replacing the traditional toxic compounds.

Keywords:

• potassium sorbate
• antifouling
• reversible effect
• Balanus amphitrite larvae

Acknowledgements

The authors thank Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Comisión de Investigaciones Científicas de la provincia de Buenos Aires (CIC) and Universidad Nacional de La Plata (UNLP) for their economic support. They also thank the Club de Motonáutica of Mar del Plata for the permission to use their marine testing site and the anonymous reviewers who provided useful comments on the manuscript.