Organic alternatives to copper in the control of marine biofouling

Abstract

Since the ban of tributyltin, the use of large amounts of copper in antifouling formulations has been the main reason for a low occurrence of animal fouling on ship hulls and, consequently, important fuel savings (Schultz, 2007). However, doubts about its environmental profile (see Chapter 19) have encouraged considerable efforts aimed at identifying antifouling alternatives to copper. This chapter includes information about three of the new antifouling candidates that are being identified worldwide. First, the use of sodium benzoate and ferric benzoate, which have demonstrated antifouling effects both in aqueous solutions and as part of soluble matrix paints, is presented. Secondly, medetomidine, a non-toxic pharmacological substance showing activity at very low amounts and interacting strongly with paint surfaces, is presented. Finally, we discuss the use of quebracho tannin and aluminium tannate, and their potential activity with fouling organisms. The use of unconventional organic chemicals provides an alternative solution in response to the demands for an effective antifouling strategy to replace copper.