Analysis of Environmental Impact of Vessel Antifouling Coatings in Nigerian Coastal Waters

Antifouling coatings applied to vessel hulls prevent biofouling accumulation and reduce fuel consumption but introduce potentially toxic compounds into the marine environment. This study analyses the environmental impact of vessel antifouling coating types in use among vessels operating in Nigerian coastal waters, with particular attention to tributyltin legacy contamination and the transition to biocide-containing tin-free formulations. A professional environmental review methodology was employed, using sediment and water column sampling from ten berth locations at Lagos, Port Harcourt, and Warri ports, structured interviews with ten ship repair facility managers, and review of antifouling product procurement records. Samples were analysed for tributyltin and copper compounds. Findings indicate that tributyltin contamination persists in sediments at berths historically used by older vessels, at concentrations above the threshold of ecological concern for sensitive invertebrate species, despite the international ban on tributyltin-based paints. Current antifouling practice among local operators is dominated by copper-based paints applied without hull surface preparation, reducing coating efficiency and increasing leaching rates. Awareness of the International Convention on the Control of Harmful Anti-Fouling Systems on Ships is minimal among smaller vessel operators and repair yards. Recommendations include sensitisation campaigns on AFS Convention requirements, monitoring expansion to additional port sediment sampling points, and promotion of silicone-based foul-release coatings as an environmentally preferable alternative. Keywords: antifouling coatings, tributyltin, marine environment, copper biocide, AFS Convention