Funny, how little we know about the Deep Blue. In flatter seas, like the North Sea or the Baltic Sea, organic material like shoes, would be first to vanish.
Tanned leather. The stuff is quite repulsive to organic contamination, since they weren't exactly using the gentlest of chemicals and techniques in 1912. You can see some "clothes" as well that are probably similarly tanned leather coats or tarps that were about.
For the record, tours are still being offered, first dive to run next year. And the French pretty much made off with the whole crows' nest, it's just plain gone. There's a number of places on the wreck where Ballard and company found damage from salvors, either resting their submarines on the wreck (why for the love of god would you risk JOINING her on the bottom) or else thumping into it unintentionally.
Titanic Inc. has been doing a lot to prevent further salvor dives, and there is an 'agreement' if not an outright treaty between the Americans, Brits, and Canadians put through on the centennial of the sinking. In all honesty, that's about as effective as a treaty that the moon is made of cheese, since it's not like we can station guards or anything at the site.
As far as Halomonas titanicae goes, it's a neat little bacteria - an extremophile, one that thrives only in extreme salt environments, and was completely new. The thing goes after manganese and sulfur, from what I've read, and provides its own heavy oxidation to dissolve and eat these compounds. It's also got a unique molecule that changes its structure from regular bacteria enough so that it can live at that pressure. It can't have been recently introduced, since Ballard and company found its presence quite heavy in 1985.
It means that 100-pounds-a-day figure's been going on since early on...36,500 pounds of steel a year being dissolved, over as much as a century...is it any wonder the wreck's becoming a literal ghost on the seafloor? Add in the pressure of a consistent 1.5kt seafloor current pressing on the hull as it weakens.
Thank god Ballard found her when he did. Otherwise Titanic would be one of the great maritime mysteries, in a few more years.
