Corrosion behavior of thermal sprayed Al and Al/nano-Al2O3 composite coatings in artificial seawater in the presence of Escherichia coli bacteria were investigated. A biofilm has been built-up on the coating surfaces following the colonization of the bacteria after 7 days soaking in the solution. The bacteria related biofilm was used as the simplified model for examining the anti-biocorrosion performances of the marine coatings. The biofilm enhances the corrosion resistance of the Al-based coatings in early stages. Simulated results using equivalent circuit models provide direct electrochemical information about the liquid/surface interfaces, further elucidating the anti-biocorrosion mechanisms of the coatings. (C) 2016 Elsevier B.V. All rights reserved.