An area four times the size of Vancouver Island is home to smoking vents, volcanic islands just under the water and a staggering abundance of life
A shortspine thornyhead at Dellwood seamount. Photo: Ocean Exploration Trust/ Northeast Pacific Seamount Partners
Slowly and deliberately, two scientists and a pilot were lowered into the water in a submersible about the size of a shipping container.
The sub, Alvin, was there to confirm what a 1982 bottom-dredging expedition had accidentally stumbled across: deep down, chimneys were spewing volcanic heat and gases into the ocean. Scientists had discovered the first deepsea vents in the world seven years prior, along the Galápagos Rift, inspiring a flurry of research and public interest into what became one of the greatest biological discoveries of the 20th century. Alvin had been there, too.
Alvin had recovered hydrogen bombs and would later dive on the wreck of the Titanic, but many of its most valuable contributions have been to science. This day would be one of the latter.
It took Alvin two hours to descend the 2,200 metres to the sea floor.
“It’s just a long way down,” says chemical oceanographer John Lupton, who was aboard the Wacoma that day. The discovery was startling: six-storey towers looming over the ridge, two kilometres down, one after another after another.
“In my experience, it’s the most active 15 kilometres anywhere,” Lupton says.
That activity fuels an alien ecosystem. The gas emanating from the sea floor is rich in sulphides, which can only be converted to food by extremely specialized organisms. Creatures that host these microbes in their gut dart in and out of the superheated water in a dance with death, gathering enough of the life-giving gas to feed their microbes without being cooked alive. A dozen species would eventually be discovered there that exist nowhere else on the planet, even at other vent sites — including the record-holder for the upper temperature limit for life, 121 degrees C.
On a normal patch of sea floor you could find a handful of worms or brittle stars in a square metre. A plot of the same size at what became known as the “Endeavour vent field” could hold up to half a million animals. The sheer volume of creatures is comparable to what would be found in a tropical rainforest.
This explosion of life exists far below where any light can reach. Hydrothermal vents are the only known ecosystems on the planet that exist completely independent of the sunlight that directly or indirectly feeds every other living thing. MORE