"In the most remote, inhospitable places, you can actually have higher activity than their surroundings," researcher Ronnie Glud, a biogeochemist at the Southern Danish University in Odense, Denmark, told OurAmazingPlanet.
Sediments from Challenger Deep also had significantly higher levels of microbes and organic compounds than the nearby, more elevated site. The investigators suggest the Mariana Trench acts as a natural trap for sediments from up high. Similar effects are seen in other submarine canyons.
"It acts as a trap just because it's a big hole. If you have a hole in a garden, it just fills up because things blowing over it tend to fall in, and the same is true with the seafloor," Glud said. The trench is also located in a subduction zone where one of the tectonic plates making up the surface of the Earth is diving under another, "and these areas are very unstable, and frequently see earthquakes that can trigger mudslides that transport material into the trench," he added.
Microbes, microbes everywhere
Another team of scientists recently discovered communities of microbes thriving in the oceanic crust. That research looked at rocks up to about 1,150 to 1,900 feet (350 to 580 m) below the seafloor under about 8,500 feet (2,600 m) of water off the coast of the northwestern United States. These microbes apparently live off energy from chemical reactions between water and rock instead of nutrients snowing from above.