Steel marine structures, including shipwrecks, provide foci of biodiversity when they develop into artificial reefs. Development begins with deposition of a biofilm. The effects of contaminants from oil spills on biofilm microbiomes, microbially-induced corrosion (MIC) and metal loss may impact preservation of marine metal structures. This study was undertaken to address the consequences of oil spill effects to biofilms, and subsequent impacts on metal corrosion, and ultimately, preservation of metal structures, including historic shipwrecks in the ocean.