Hydrothermal vents are epicenters to some of the most extreme geochemical processes on the planet. The hot spots of geological activity make their home on the ocean floor, where jets of scalding hot, mineral-rich water spew forth into the depths of the near-freezing ocean.
Under the right conditions, these intense underwater processes give rise to chimney-like vents called "black smokers." Now, scientists believe a newly discovered set of black smokers to be the deepest undersea vents on Earth. What's more, the vents are positively teeming with previously undescribed life.
The volcanic mineral spires were discovered in the western Caribbean sea, in a region of the ocean floor known as the Cayman Trough. Using two deep-sea diving vehicles, a research team led by marine geochemist Doug Connelly was able to spy the chimneys churning out plumes of acidic, black-tinged water from an astonishing depth of 5,000 meters — that's over three miles below the ocean surface, and close to a kilometer deeper than any vents we've seen before.
Featured here is video of the newly discovered deep sea vents doing what black smokers do best: pumping out vast quantities of super-heated, sulfur-rich water. (These roiling jets of sooty fluid were observed drifting as high as 1100 meters above the ocean floor.) Connelly and his team were unable to measure the temperature of the vents precisely, but suspect that they could exceed 450 degrees Celsius. This would make them not only the deepest vents ever discovered, but the hottest.
But there's more. Just a few seconds into the video, another exciting discovery by Connelly and his team comes into view: Thousands upon thousands of shrimp can be seen swarming the outside surface of the columns, like a crustacean carpet. According to Connelly and his team, these shrimp belong to a previously undescribed species, are eyeless, and have light-sensing organs on their backs, which the researchers think may come in handy when the shrimp are navigating the near pitch-black depths of the Cayman Trough. (Also visible in the video are hundreds of white-tentacled anemones, which can be seen congregating around cracks in the sea bed where water — warmed and enriched by geochemical activity in the Earth's interior — seeps through.)
Incredibly, the new species of shrimp was also discovered swarming vents located on the upper slopes of an undersea mountain called Mount Dent (Dent vents can be seen in the video from 43 seconds on). Why is that surprising? Mount Dent rises nearly three kilometers above the seafloor of the Cayman Trough. Prior to the the observations of Connelly and his team, hot and acidic vents like these had never been seen in an area like Mount Dent — in fact, notes Connelly, "[we usually] don't even look for vents in places like this." If deep sea vents can make a home on undersea mountains like Dent, they may be more widely dispersed throughout the world's oceans than we once thought.
"One of the big mysteries of deep-sea vents is how animals are able to disperse from vent field to vent field, crossing the apparently large distances between them," explains biologist Jon Copley, who co-led the team of researchers. "But maybe there are more 'stepping stones' like these out there than we realized."
The researchers' findings are published in the latest issue of Nature Communications.
Images and video courtesy of The University of Southampton/NOC