Metal contamination of intertidal sediment and macroalgae in an area impacted by paint from abandoned boats

Abstract

Metals commonly employed in boat paint (Ba, Cr, Cu, Pb, Sn and Zn) have been determined in 63-μm-fractionated intertidal sediments and in Ulva lactuca and Fucus vesiculosus sampled in the vicinity of abandoned vessels. Metal concentrations in sediment were elevated but highly variable, both between sites and amongst replicates from the same site (e.g., mean Cu ~ 100 to 1200 mg kg-1; mean Pb ~ 130 to 6900 mg kg-1) due to heterogeneous contamination by metal-rich boat paint particles. Concentrations of all metals except Zn were higher in U. lactuca than F. vesiculosus but in both species metal levels were also elevated and variable. These observations were attributed to contamination by sediment particles and physical and chemical interactions between fine, suspended or deposited paint particles and the algal surface. The latter interactions act as a means by which boat paint metals may enter the foodchain.