More than 13,000 feet under the sea, scientists have found a volcanic wonderland unlike any other place on Earth.
The newfound ecosystem is crawling with life—hairy snails, ghostly shrimp, and weird worms—including some species that may be new to science. (See pictures of creatures found on volcanic vents in the Gulf of California.)
The discovery involves three new hydrothermal vents that exist along the Mariana Back-Arc, a dynamic zone between Papua New Guinea and Japan where new ocean crust is constantly bursting forth. The Back-Arc is part of an active geologic region that includes the Mariana Trench, the deepest place on Earth.
Finding the new vents was “a big breakthrough, a big thrill for everyone,” says team member William Chadwick, a submarine volcanologist with the U.S. National Oceanic and Atmospheric Administration.
“There’s a lot to learn about these habitats—not only the neat animals, but how they fit into the global picture,” says Andrew Thurber, a deep-sea ecologist at Oregon State University who was not part of the expedition team.
“This particular [site] is pretty different than those often studied, so it’ll add to our overall understanding of the global ecosystem.”
Enter the Luck Dragon
Scientists found the vents thanks to SuBastian, a new kind of remotely operated vehicle (ROV) developed at the Schmidt Ocean Institute in Palo Alto, California.
Guided from the surface by the Schmidt research vessel Falkor, the vehicle can stay underwater for weeks at a time.
The Falkor did an initial investigation of the Back-Arc in 2015, but that expedition didn’t have SuBastian. Scientists on that trip instead observed what looked like vents and active lava flows using remote sensors, and then marked the approximate locations on a map for future study.
“It’s like if we were in a helicopter looking for which house in a neighborhood had their fireplace on, and we’re lowering sensors to look for smoke coming out of a chimney,” says Chadwick.
That meant there was no guarantee the SuBastian team would be able to find the vents again. But during a three-week expedition in December, luck was on their side: The team located the three chimneys on their very first dive with the ROV.
On that dive, SuBastian flew into a live underwater volcano and was engulfed in smoke. Its bottom half and entire front portion were coated in sulfur as the volcano erupted.
“We came to a point where droplets of molten sulfur were spitting up, and we realized we needed to get out of there,” says lead mechanical engineer Jason Williams. “So that was obviously a little stressful—and exciting.”
The ROV was not damaged. The bottom of the ocean is very cold, and though molten sulfur spews out from the chimneys at up to 350 degrees Fahrenheit, it cools almost instantly.
Over the next couple weeks, the team conducted their research in 12-hour dives, getting up before dawn each day to prep the ROV and send it on its two-hour commute to the bottom of the Back-Arc.
When the vehicle came back to the surface laden with samples, the scientists streamed out of the control room and descended upon its bounty. They spent evenings in the lab processing what was collected, while the ROV team started getting SuBastian ready for the next day’s dive.
“It’s a long day each day,” says Chadwick. “It’s a bit exhausting. We stagger the hours so the people who were up late can sleep a little, and the others can run things in the early hours.”
Hydrothermal vents are epicenters of diversity in the deep sea. Since much of the ocean floor is mud, the sudden presence of hard rock provides attachment points for corals and sponges, which in turn changes the dynamic of life in the immediate vicinity.
Vents also provide another crucial resource for evolving organisms: heat. These vents churn out up to 3 percent of the total energy in the deep sea. (Also see "Weird Animal World Discovered in Deepest Pacific Ocean Vents.")
The newly discovered vents are especially unusual, because they resemble no other known environment on Earth—except each other.
Though their physical topography differs in size, layout, and other superficial features, the chimneys at all three sites display a remarkably similar chemical makeup even though they’re each up to a hundred miles apart.
“Not all vents function the same, they don’t all have the same temperature or release the same chemicals,” says Thurber. “That leads to different sorts of animals.” Studying their genetic makeup may one day reveal new avenues for diverse applications, from medicine to household products.
“All these crazy critters—this expedition definitely got to see lots of cool animals endemic to these vents,” adds Thurber.
Now that the expedition is over, the scientists will take the data and samples to dozens of collaborators back on land. The snails might be sent to someone in Sweden; the shrimp may go to someone in Australia.
It’ll take a year or two to really sift through everything and figure out whether they have any new species or other surprises. In the meantime, the scientists will give the ROV team input for potential ways to improve SuBastian for future dives.
As for the Back-Arc, the majority of the region—more than 370 miles of it—remains unexplored.
“That’s kind of the fun thing about going to new sites,” Chadwick says. “There’s a good chance of finding new things nobody’s ever seen before.”
Editor's Note: An earlier version of this article gave an incorrect temperature for molten sulfur coming from the hydrothermal vents.