Effects of oyster as macrofouling organism on corrosion mechanisms of a high-strength low-alloy steel

Adhered oysters can cause complex corrosion of fouled steel structures, with localized crevice corrosion being the most severe. A crevice corrosion model of steel caused by oysters is proposed, showing that oyster secretions can penetrate into the oyster/steel interface and act as a stabilizer of the rust layer, enabling tight attachment and thereby slowing the metal corrosion rate. In contrast, oxygen concentration cells, enriched Cl-, anaerobic bac-teria, the presence of organic free radicals and oxidative cross-linking during the curing process of oyster se-cretions act as localized corrosion accelerators facilitating the crevice corrosion process in the oyster/steel gap.