Deep-sea explorer Robert Ballard, perhaps best known for his discoveries of the Titanic and the German battleship Bismarck, has a vast appetite for the unknown.
Exploring the mysteries of the Cayman Trough and other regions of the Caribbean, Mr. Ballard and his team hope to discover previously unknown species and shipwrecks, as well as hydrothermal vents, which are the focus of the search.
“Our job is to go where no one has gone before on planet Earth,” he said Sunday after the exploration vessel Nautilus returned to Grand Cayman for a personnel exchange after a week at sea. “We’re equal opportunity explorers, so we love biology, geology, archaeology and anything that’s never been seen before.”
Mr. Ballard first dove the Cayman Trough in the late 1970s, searching for hydrothermal vents. He dove on Mount Dent, the underwater peak on which the Von Damm vent site was discovered in 2009, without happening across the vents.
“But I got them [hydrothermal vents] a few months later in the Galapagos, so I only missed them for a few months,” he said.
Mr. Ballard and Katherine Croff Bell, both of the Ocean Exploration Trust, are leading the team of researchers, scientists, engineers, students and educators aboard the Nautilus who are aiding in the mission to map and explore the more poorly understood regions of the Caribbean Sea.
Lifestyles of the extremophiles
The exploration of hydrothermal vents are key for several reasons, Ms Croff Bell said. First, there is the possible connection between underwater and space exploration. NASA hopes such research will establish whether the technology used to monitor hydrothermal vents could also be used to search for life on other planets.
The exploration of hydrothermal vents may also reveal truths about our own planet. Ms Croff Bell said scientists have hypothesized that life on Earth originated in and around hydrothermal vent sites.
Despite the harsh environment, with temperatures that drop from beyond boiling to below freezing, the hydrothermal vent sites are teeming with life. “There are very few species but a huge abundance of those that exist,” said Leigh Marsh, a post-graduate student at the University of Southampton.
Organisms that thrive in harsh conditions are known as extremophiles. In and around the hydrothermal vents, these organisms include specially adapted species of snails, crabs, worms, shrimp and bacteria.
Previous expeditions discovered a new species of eyeless shrimp and tubeworms never previously recorded at vent sites in the Atlantic.
“We don’t know yet if there are any new species,” Ms Croff Bell said. “There are a lot of incredible creatures and we’re collecting samples of many of them, so it will take some time to get them back to the lab to analyze them to determine whether or not they’re new to science.”
The expedition uses two remotely operated vehicles, Hercules and Argus, to collect biological and geological samples along the ocean floor.
There are four known hydrothermal vent sites in the Cayman Trough: Von Damm, Piccard, Walsh and Europa. The first three are named after famous oceonographic researchers and explorers; Europa was named after Jupiter’s frozen moon.
Hercules and Argus
The research team aboard the Nautilus uses Hercules and Argus to dive the mysterious depths of the Cayman Trough. Argus is connected to the Nautilus at all times via a fiber-optic cable.
The most maneuverable of the two ROVs, Hercules is equipped with high-definition cameras, high-powered lights, two robotic arms, a temperature probe, a vacuum sampler and a lucky tiki.
“The bosun on our Titanic cruise in 2004 carved us that,” Ms Croff Bell said.
“The weather was really bad and he carved that and it cleared right up, so on the crew’s dive checklist is ‘oil the tiki before every dive.’”
But even Hercules’ lucky tiki would provide little relief if Argus was not around. Hercules is tethered to Argus via a neutrally buoyant cable and cannot operate in isolation.
“[Argus] is sort of an eye in the sky above Hercules providing lighting and cameras and making sure that we’re not going to run into a cliff or anything,” Ms Croff Bell said, adding that Argus also counteracts the movement of the ship, allowing Hercules to remain level even in rough seas.
The vehicles’ maximum depth is 4,000 meters, or almost 2.5 miles. Ms Croff Bell said. However, the vehicles may be upgraded to dive even deeper in the future.
“We’ll be based in the Caribbean for the next two to three years and then we’re going to work our way across the Pacific over to the western Pacific, and over there the oceans are much, much deeper, so we anticipate in the next couple of years we’ll be upgrading the vehicles so they can go to deeper depths,” she said.
Nevertheless, Hercules and Argo have plenty of unexplored ocean to dive.
“There’s a lot of territory within the 4,000-meter range that we can cover,” Ms Croff Bell said. The Nautilus and her crew will remain in the Cayman Trough until the end of the month. The ship will return to the United States in September to avoid peak hurricane season before returning to the Caribbean.
Ms Croff Bell said the Nautilus will visit Puerto Rico and Antigua before eventually ending up off the coast of Grenada to explore Kick-’em-Jenny, the only active underwater volcano in the region.
“There was a new species of worm found in Kick-’em-Jenny 10 years ago and nobody’s been back there for 10 years, so we’re really excited to get down there and check it out and see what’s going on,” she said.
The expedition can be viewed live on www.nautiluslive.org