Thousands of feet beneath the surface of the ocean, scientists have discovered previously unknown hydrothermal vents, teeming with life. These gaps in the seafloor, which blast out scalding, mineral-rich water, are the first of their kind discovered in a 423-mile stretch of the Mid-Atlantic Ridge since the 1980s, per a statement from the National Oceanic and Atmospheric Administration (NOAA).
“We had the right tools, the right strategy and enough time to systematically search,” David Butterfield, an ocean chemistry expert at the University of Washington and the NOAA Pacific Marine Environmental Lab in Seattle, tells Mongabay’s Elizabeth Claire Alberts. “Everything worked well, and the weather cooperated.”
Hydrothermal vents occur where tectonic plates spread apart underwater. At these sites, seawater percolates through the cracks in the ocean floor, picking up minerals along the way. The fluid is superheated by magma below the Earth’s crust and becomes buoyant, rising back up and shooting out the vent. Water bursting from the vents can reach up to 750 degrees Fahrenheit—hot enough to melt lead—but it doesn’t boil due to the high pressure at that depth.
As the metal-rich vent water mixes with cold seawater, chemical reactions cause minerals such as sulfur to come out of the solution and form a solid structure called a chimney around the vent. Extreme bacteria that live in these harsh environments survive off of energy from the vent chemicals, instead of sunlight.
“Hydrothermal vents are fascinating environments,” Maggie Georgieva, a vent researcher at London’s Natural History Museum who was not involved with the finding, says in a statement. “There have been hydrothermal vents since the very early history of the planet—and they could be where life on Earth first started.”
The newly discovered sites are known as black smoker vents, which create chimneys of iron sulfide and emit dark-colored plumes—the hottest of all hydrothermal vents. The scientists spotted these high-temperature havens at three distinct Mid-Atlantic Ridge sites, located about 6,600 feet below the surface.
There, they found a wide variety of life, including swarms of vent shrimp and a rare big fin squid, per a statement.
Aboard a research vessel called Falkor (too), the international team of scientists mapped an area of seafloor approximately the size of Manhattan, with the help of autonomous underwater vehicles and a remotely operated vehicle called SuBastian. They initially set out to find a different kind of hydrothermal system driven by serpentinization—a chemical reaction between seawater and mantle rocks, per NOAA. Such a system was discovered in 2000 and dubbed the “Lost City.”
The vents along the Mid-Atlantic Ridge have attracted interest not only for their scientific significance, but also for commercially valuable minerals that could be extracted via deep-sea mining. Researchers don’t know how deep-sea mining would affect these vent environments, per the statement.
“There is still so very, very much more that we need to learn about how these ecosystems function, how nutrients are cycled among and within the vent animals, and the sheer biodiversity of these animals,” Dawn Wright, a deep-sea biologist and chief scientist of California-based mapping outfit Esri, who was not involved with the expedition, tells Mongabay.
“With new species consistently being discovered, there may even be a cure for cancer or Covid in these places,” she tells the publication. “And we need to understand much more about the role that the vents play as a sink for carbon and methane, two of the most troublesome greenhouse gases.”