By Jeffrey Marlow   From WIRED

An octopus lingers near a bed of giant mussels discovered at a new methane seep in the Caribbean Sea. (Image: Ocean Exploration Trust)

The world’s oceans are a source of wonderment, sustenance, and, at times, peril. None of the Seas encapsulates this dramatic range quite like the Caribbean, with beautiful coral reefs, important fish stocks for more than a dozen nations, and an active yet frighteningly unpredictable seismological profile.

Legendary ocean explorer Bob Ballard led a team of scientists and engineers to the Caribbean last year on an expedition that was part forensic geology, part risk assessment, part unbridled exploration. The resulting documentary – Caribbean’s Deadly Underworld – premieres on May 18th on Nat Geo Wild, offering a dramatic, if somewhat overwrought, look at the team’s frustrations, uncertainties, and discoveries.

Ballard has had a richly varied career (playing a leading role in the discovery of the Titanic and hydrothermal vents), but his most recent chapter as the founder of the Ocean Exploration Trust has afforded an unprecedented freedom of mission. “I played the NSF [National Science Foundation] game for a while,” he recalls, referring to the competitive grant-seeking process that many ocean researchers pursue in order to fund their research aims and expeditions. “But scientists can only propose very safe things, essentially going to well-known sites and investigating a slightly different aspect of the area.” It’s a risk-averse strategy that seeks to make the most of public funds, but to Ballard, it leaves a lot on the table. He’s fond of quoting the 19th century French philosopher and aphorism machine Henri Poincare, who wrote, “It is by logic that we prove, but by intuition that we discover.”

The Trust’s ship Nautilus, funded largely by private money, has spent much of the last decade in the Black Sea, plying the anoxic basin for well-preserved shipwrecks. But it’s not the best neighborhood these days, given the political turmoil in Crimea, and the vagaries of geopolitics have turned out to be science’s gain. In the Caribbean, Ballard and his team sought evidence of tsunamis past. By understanding how, where, and when destructive waves formed in the past, the thinking goes, it might be possible to prepare for future events.

Tsunamis can form whenever water is vertically displaced, whether by seafloor earthquake, volcanic debris avalanche, or underwater eruption. And while the team found many dramatic cliffs bearing scars of debris flows past, they weren’t able to confidently date them.

In the Lesser Antilles, off the coast of Granada, Nautilus deployed its robotic fleet to explore Kick’em Jenny, an evocatively named underwater volcano that has erupted roughly every decade since its discovery. The last burst was in 2001, and the diminished temperature of seeping fluid (down to 350 C from about 500 C many years ago) suggests that the feature is capped, like a corked bottle of champagne. “It’s getting ready,” Ballard says ominously, “it’s overdue.”

Following Kick’em Jenny’s slope downward, the team happened across an unexpected oasis, with foot-long mussels and dark streaks of sediment indicative of bizarre subsurface plumbing. It appears that underwater landslides compressed organic-rich goo, which sent bubbles of methane spiraling upward through the sediment. The microbial community, which drives the entire ecosystem, no doubt contains novel constituents, given the fluid’s likely blend of methane and volcanic, sulfur-bearing chemicals.

To Ballard, the find revealed a silver lining of a catastrophic event. While the tsunami that likely resulted from the landslide wreaked havoc on the surface, “there are now these amazing living systems that it triggered.”

The Nautilus is returning to the Caribbean next month, with an agenda of both follow-up investigations and new, uncharted explorations. “Most of my biggest discoveries have been by accident,” Ballard says. “And this was no different – we found something completely unexpected, an entirely undiscovered ecosystem.”

For more on this story go to: http://www.wired.com/2014/05/in-pursuit-of-the-caribbeans-hidden-dangers/