Life thrives even at deepest spot on Earth
Washington: Life finds its way, even in total darkness at the deepest spot on Earth, scientists say after finding fields of bone-white clams clustering at hydrothermal vents in the western Pacific Ocean which lie as deep as 5,860 meters below the surface.
The discovery, made during a September 2010 expedition, was utterly unexpected, according to an international team which detailed its findings in the Proceedings of the National Academy of Sciences.
The researchers aboard a Japanese manned submersible were conducting research dives to study the geology of a region of the Mariana Trench, the deepest trench on Earth, which lies several hundred miles south of the island of Guam.
The team happened upon the hydrothermal vents just 80 km northeast of the Challenger Deep -- the deepest spot on the planet, where the seafloor plunges to 35,700 feet.
In addition to clams, the team saw and collected various deep-dwelling sea anemones, snails, a type of comb jelly known for producing shimmering bioluminescence, and one crab that has long, reaching front pincers. The team retrieved 30 clams from the site, along with 77 kg of rocks.
"These kinds of low-temperature fluid vents are very difficult to find and may be very widespread on the ocean floor," lead author Robert Stern, a geoscience professor at the University of Texas, was quoted as saying by LiveScience.
"And they can sustain high-biomass communities. This has implications for the chemical composition of the oceans and the distribution of deep-sea life," he said.
The finding comes on the heels of a string of revelations about life at hydrothermal vents around the globe. Scientists have already uncovered yeti crabs from vents near Antarctica, and expeditions to the Piccard/Beebe sites in the Caribbean uncovered eyeless shrimp.
The Pacific vents, which the team named the Shinkai, are a cooler type of hydrothermal vents and are not superheated by volcanic forces like the Piccard/Beebe vents, the deepest and active volcanic vents at 16,400 feet below the surface.
Stern said his team is planning to return to the region within the next year or two.