A new form of aggressively corrosive bacteria found growing on the sunken Titanic could hold major implications for new protective marine coatings and future ship demolition, researchers say.
The “bad bacteria,” Halomonas titanicae, was identified through DNA technology from a sample taken from the shipwreck and appears to be accelerating the wreck’s deterioration.
The discovery was made by Dr. Henrietta Mann, of Dalhousie University’s Department of Civil Engineering, and Dr. Bhavleen Kaur, a former graduate student at the university. Their research has just been published in the International Journal of Systematic and Evolutionary Microbiology.
Dalhousie is located in Halifax, Nova Scotia. The wreck of the Titanic is a few hundred miles off the coast of Newfoundland. The “unsinkable” luxury liner struck an iceberg April 14, 1912, on its maiden voyage from England to New York and went down with 1,517 people aboard.
The wreckage was not found until 1985, when a joint American-French operation found a split hull about 13,000 feet below the surface of the North Atlantic.
The new species was discovered on one of Titanic’s “rusticles”—highly porous, dark orange formations resembling rusty icicles—nearly four kilometers (almost 2.5 miles) under water, researchers reported.
H. titanicae is able to adhere to steel surfaces, creating knob-like mounds of corrosion, according to information provided by the university. A similar bacterial corrosive process is believed to be responsible for the formation of the “rusticles.”
H. titanicae may work with other organisms to speed up the corrosion process of metal, the university said.
Researchers do not yet know if the new species was present on the Titanic before or after it sank, or whether the strand is unique to that wreck.
The unique strain was identified in 2006 and initially dubbed BH1 (for Bhavleen and Henrietta). But identification was just the first step, the university said.
Next, the researchers had to determine if they had discovered “a good bacteria or a bad bacteria,” said Mann. “So we tried to find out if strain BH1 had bio-corrosive ability.”
“We did this by putting a bacteria sample on the surface of small metal tags, we call coupons,” Mann said in an article on the university’s web site. “The BH1 cells stuck to the surface of these coupons and eventually destroyed the metal. So we knew we had a bad bacteria.”
“These bacteria can seriously damage ship and pipeline structures,” she continued. “Therefore, it would be a good idea to continue to study these bacteria in more depth.”
‘Nothing But a Rust Stain’
Researching ways to arrest the bacteria’s growth could provide major benefits to the maritime industry, Mann said.
“If we could discover a way to hold back or stop the bacteria from eating the metal, we could help the maritime industry avoid heavy replacement costs to their ships and pipelines. This work was started in biological engineering, but is very important to civil engineers in industry.”
Corrosion is beginning to overtake the 50,000 tons of iron in the Titanic, the world’s largest underwater metal structure.
"In 1995, I was predicting that Titanic had another 30 years," Mann told gizmag.com, a site that reports on innovation and emerging technologies. "But I think it's deteriorating much faster than that now ... Eventually there will be nothing left but a rust stain."
Still, the bad bacteria may have a silver lining. On one hand, it presents a new microbial threat to the exterior of ships and underwater metal structures such as oil rigs.
On the other hand, the bacteria may eventually be harnessed in some fashion to dispose of old ships and oil rigs.
“We believe H. titanicae plays a part in the recycling of iron structures at certain depths,” said Mann. “This could be useful in the disposal of old naval and merchant ships and oil rigs that have been cleaned of toxins and oil-based products and then sunk in the deep ocean.”
Additionally, further research into H. titanicae may lead to innovations in undercoating treatments for naval structures, researchers say.
“We don’t know yet whether this species arrived aboard the RMS Titanic before or after it sank,” Mann said. “We also don’t know if these bacteria cause similar damage to offshore oil and gas pipelines.”
“Finding answers to these questions will not only better our understanding of our oceans, but may also equip us to devise coatings that can prevent similar deterioration to other metal structures.”