A bacterial buffet of Titanic proportions
The famous White Star Line vessel, once presumed unsinkable, rests 3,800 metres under the North Atlantic Ocean. Just 600 kilometres from the coast of Newfoundland, the RMS Titanic struck an iceberg and the rest is history.
Although the majority of the damage obtained was caused from the time of the collision to the point of landing on the sea bed in 1912, it was over 70 years till its discovery in 1985, and the ship wreck appeared to be well preserved. As several scientific expeditions returned to the Titanic, a noticeable amount of damage was starting to show. Some areas would show little change, while others showed signs of collapse or wear as if something had fallen or rubbed against it. Missing or moved items, such as the crow’s nest, suggest more expeditions (most likely privately owned) had visited the wreck, and not taken as much care as needed.
How long will the Titanic last?
The main body of the ship will remain mostly intact for presumably decades, however certain areas like the bow may have only a couple years before it collapses. Originally it was predicted the ship wreck would still remain for many hundreds of years, but what has caused the time frame to rapidly decrease?
The answer, a variety of organisms and the water currents themselves are slowly eating away what remains. Molluscs have eaten away most of the wood, leaving the enormous metal hull to bacteria and fungi. The iron-rich metal provides a large amount of nutrition for a particularly voracious bacteria species named specifically after the Titanic.
Halomonas titanicae, first discovered by Dr. Henrietta Mann, is a rust-eating bacterium that is causing such rapid decay that the vessel may serum to disintegration by 2030. The microbes create a self-contained ‘rusticle’ as they eat away at the wreck. In 1996, an estimated 650 tonnes of rusticles were seen to be growing on the outside of the bow section alone. Rusticles are now found all over the outside and interior of the ship, growing larger as more of the wreckage is consumed. It is estimated that within a couple of years, large parts such as the masts will completely crumble due to an infestation of rusticles. Bacteria such as H. titanicae can survive in these harsh environments due to the help of a natural compound known as ectoine. It is found in high concentrations within halophilic (salt-loving) microorganisms. It is used to provide a resistance to salt and temperature stress on cell membranes, due to high osmotic pressure.
But it isn’t just biological factors that are causing the ship to break-down. The Titanic sits within the Titanic Canyon (again, named after the ship), which is constantly swept by the Western Boundary Current. Small holes in the hull and deck have been eroded larger and larger by the back-and-forth movement of the currents, 24 hours a day. The currents at these depths can be strong and highly changeable.
Can the Titanic be saved?
At 2.3 miles down and a pressure of 6000 pounds per square inch (410 bar), the vessel will most likely be left to nature as salvaging or attempting to preserve what remains is near impossible. However this isn’t completely a bad thing, for the ocean that is. The steel and iron of the ship will continue to be broken down by the bacteria. The small particles of iron will enter the water column and be captured by photosynthesising organisms. From there, it will work its way up the food chain through the ingestion of each consecutive organism, where eventually it may return back into the ocean.
The ship wreck also provides a habitat for a number of different larger species, as well as the microorganisms that feed upon it. During an expedition in 1991, a total number of 28 species were observed. Sea anemones, crabs, shrimp, starfish, and rattail fish – some up to 1 metre long – were all found in and around the debris field. Some species were found that have never been seen anywhere else before. An unknown species of sea cucumber was discovered on an expedition by James Cameron in 2001. The wreck has been described as an “oasis” within the deep, and although it has remained for the last 100 years, it may soon become a simple “rust-stain on the bottom of the Atlantic” much sooner than we think.