The authors examined the physiochemical and microbiological properties of archived rusticles from World War II shipwrecks in the Gulf of Mexico. Rusticles, iron (Fe)-rich accumulations on shipwrecks in marine environments, have long been assumed to be the result of low alloy steel corrosion. In many cases the assumed corrosion has been attributed to biodeterioration because of the presence of specific types of bacteria associated with the rusticles. However, archived rusticles from WWII shipwrecks in the Gulf of Mexico (GOM) do not have the mineralogical layering typical of iron corrosion products. Moreover, spatial relationships between bacteria and rusticles cannot be interpreted as biodeterioration. The authors concluded that environmental Fe plays a role in rusticle formation and differences in Fe concentrations can be used to explain differences in rusticle size and distribution with depth in the GOM. Both biotic and abiotic mechanisms for Fe accumulation are provided.
