Smoking Ocean Vents Found in Surprisingly Shallow Water
Scientists have found new hydrothermal vents off the Azores, and they may harbor unique life.
A new field of hydrothermal vents was just discovered in the Azores. Hydrothermal vents are deep-sea hot springs at the bottom of the sea floor that form unique, chimney-like structures. They are often home to strange forms of life.
“This is an extraordinary discovery since this hydrothermal field is shallower than all others known in the Mid-Atlantic Ridge,” says Emanuel Gonçalves, co-leader of a deep-sea expedition organized by Portugal’s Oceano Azul Foundation in partnership with the Waitt Foundation and National Geographic Pristine Seas.
“It’s like finding an alien environment on Earth,” says Enric Sala, a marine ecologist and National Geographic Explorer-in-Residence. “These are rare examples of ecosystems that live off energy from the center of the Earth instead of sunlight,” he says.
The Azores are nine volcanic islands in the North Atlantic Ocean. They lie about 850 miles (1,360 km) to the west of Portugal, which administers them. The newly discovered vents are just 60 miles offshore of one of the islands, and only 1,870 feet (570 meters) deep. Most vents are in more remote regions and much deeper, like the first-ever-discovered vents that are 8,000 feet deep (2440 meters), and over 200 miles offshore of the Galapagos Islands.
Operating Portugal’s remotely operated deep sea submersible “LUSO,” expedition scientists found multiple chimneys of different heights and evidence of bacteria at the new hydrothermal field.
Vents are found where continental plates meet, forming 40,000-mile-long mountain ranges or ridges that zigzag up and down the middle of the world's ocean basins like a giant zipper. The Mid-Atlantic Ridge part of this zipper runs about 10,000 miles (16,000 km) in a curving path from the Arctic Ocean, through the middle of the Azores Islands, and down to the southern tip of Africa. Sea water seeps down into the cracks and fissures created where the continental plates interact. When this seawater meets the Earth’s molten magma it gets superheated and rises up through holes or vents in the sea floor, carrying with it minerals leached from the crustal rock below. (Learn more about the discovery of such “smokers.”)
Few people thought life could survive in total darkness and under tons of pressure in the deep ocean until the first vents were discovered in 1977, says Stace Beaulieu, a marine biologist at Woods Hole Oceanographic Institution.
But now we know vents are a kind of oasis for totally unexpected lifeforms that can thrive in a toxic chemical soup, where temperatures can reach 650 degrees F (350 degrees C). Bacteria and archaea feed on the minerals bubbling up from these holes in the Earth, and they are in turn fed on by worms, crabs, and even fish that have become specialized and cannot survive anywhere else.
Over 700 unique species have been found at vents, and it is likely new species are waiting to be discovered at the new Azores vents, says Beaulieu.
