The microbes are consuming the wreck's metal, creating mats of rust bigger than a dozen four-story brownstones that are creeping slowly along the hull harvesting iron from the rivets and burrowing into layers of steel plating. The creatures also leave behind "rusticles," 30-foot icicle-like deposits of rust dangling from the sides of the ship's bow. Structurally, rusticles contain channels to allow water to flow through, and they seem to be built up in a ring structure similar to the growth rings of a tree. They are very delicate and can easily disintegrate into fine powder on even the slightest touch.
These live mats and rusticles form a communicating super-organism funneling iron-rich fluids, sulfur, and electrical charges through the collective of archea, fungi, and bacteria that thrives in the icy dark, low oxygen waters. Using DNA technology, researchers discovered that the rusticles were formed by a combination of 27 different strains of bacteria. Among the bacteria feasting on the Titanic, there was a brand new member of the salt-loving Halomonas genus.
In June 2003, NOAA’s Office of Ocean Exploration sponsored an 11-day research cruise to the wreck site aboard the Russian Research Vessel Akademik Mstislav Keldysh. The vessel is equipped with two three-person submersibles (Mir I and Mir II) capable of diving to depths of 6,000 meters; the depth of the Titanic is 3,800 meters (12,467 feet).
OE planned four Mir dives to the Titanic to assess the wreck site in its current condition, and provide an opportunity to conduct scientific observations for ongoing research. Scientists from the United States and Canada were invited to participate in the expedition.
Larry Murphy, chief of the Submerged Resources Center, National Park Service, was on hand to provide archaeology assistance and advice. His expertise on metallic shipwrecks and site formation processes from the USS Arizona Memorial directly complements NOAA’s guidelines on Titanic. Dr. George Bass, known as the “father of maritime archaeology” from the Institute of Nautical Archaeology (INA), also joined the trip to offer archaeological expertise.
More than 24 hrs of annotated, on-site video data were acquired and catalogued, used to construct a photo mosaic of the wreck site, provide a context for site characteristics, and form a better understanding of site formation processes. The stern section of Titanic, which has largely been ignored in the past because it is in a jumbled state, was specifically analyzed.
The second objective of the expedition addressed microbial communities, the rusticles, that consume Titanic’s iron and cling to the wreck like rusty icicles.
These features have been observed throughout the years. Ongoing qualitative analyses contribute to the scientific research regarding the ship’s degradation. Roy Cullimore and Lori Johnston from Droycon Bioconcepts, Inc. (DBI) of Canada organized the microbiological and rusticle observations.
A view of the bathtub in Capt. Smiths bathroom. Rusticles are observed growing over most of the pipes and fixtures in the room. Image courtesy of Lori Johnston, RMS Titanic Expedition 2003, NOAA-OE.
A 2003 expedition sent two Mir submersibles to survey the microbes that are infesting the ship and to determine their rate of growth. In 1998, four steel test platforms were placed in various locations near and on the wreck to assess the growth of rusticles on steel in different stages of fatigue. This expedition visited these platforms, and the video imagery revealed that all four showed strong evidence of rusticle growth. The longest rusticle extended 2.5 inches from the steel coupon.
One of the experiments conducted on this expedition was to see if a common species of surface-dwelling bacteria could survive exposure to the conditions at the Titanic site. In 1998, five species were sent to the site and survived for 18 hrs with losses of no more than one order of magnitude of cells. This year, the experiment was limited to one species of bacteria (Pseudomonas aeruginosa) with replication made possible using the BART reader system.
This data showed that survivors from the dive (without any protection from the conditions at the site) were impacted to a varying degree, from no reduction of cell activity to less than one order of magnitude of reduction. One of the replicates showed three orders of magnitude reduction in cell activity.
Further observations were made on the deterioration of the bow and stern sections of Titanic. From these observations it appears that the stern section of the ship is deteriorating at a faster rate than the bow section, and has been calculated to be about 40 yrs ahead of the forward section. This was determined due to the state of the steel at the stern, which was severely embrittled and distorted, providing better "habitat" for rusticle formation.
Also, because food was stored on Titanic primarily in the stern section of the ship, it supplied the initial nutrients for rusticle growth. Lastly, surfaces within the hull that had been torn apart served as a staging ground for rusticle growth.
Provided by The Daily Galaxy - oceanexplorer.noaa.gov
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