Review: Rusticle Formation on the RMS Titanic and the Potential Influence of Oceanography

Meter length iron-rich rusticles on the RMS Titanic contain bacteria that reportedly mobilize iron from the ship structure at a rate that will reduce the wreck to rust in decades. Other sunken ships, such as the World War II shipwrecks in the Gulf of Mexico (GOM) are also similarly covered. However, at the GOM sites, rusticles are only centimeters in length. Minimal differences in water temperature (a few °C) between the two sites and comparable exposure times from wreckage to discovery cannot rationalize the extreme differences in rusticle length. One possible explanation for the observed difference in rusticle size is the differing amounts of dissolved or colloidal iron at the two locations.