The central part of the autonomous instrument that was deployed to measure the O2 dynamics of the sea-bed in the Mariana Trench at a depth of 11 km. Data documented intensified microbial life in the bottom of the trench as compared to conditions at the surrounding abyssal plains at 6 km water depth.ANNI GLUDEven the deepest spot on the ocean floor supports a vigorous microbial ecosystem, according to new research. An international collaboration found that in the Mariana Trench—nearly 11 kilometers (7 miles) below the surface—microbes easily metabolize the organic matter that falls to this depth, despite enduring 1,000 times more pressure than organisms at sea level. The findings, published today (March 17) in Nature Geoscience, demonstrate that these microbial communities have evolved adaptations to survive—and thrive—under extreme pressure.
The research “shows that microbes are basically able to cope with any conditions on this planet,” said Hans Røy, a geomicrobiologist at Aarhus University in Denmark who did not participate in the research. Even at the highest pressures on the planet, “microbes appear to be just fine.” Coincidentally, the findings come hot on the heels of the discovery that microbes live in basalt rock hundreds of meters below the ocean floor.
Ocean microbes are critical players in the carbon cycle. If organic matter avoids microbial digestion as it falls to the sea floor, and remains undigested, it ultimately turns into fossil fuels. Microbes, by degrading this matter and releasing CO2, keep carbon cycling in the ocean, explained Ronnie Glud, an aquatic biogeochemist at the University ...
