An international team of oceanographers and biologists completed the first survey of bacteria in the deepest ocean depths using specially designed robotic equipment that examines the bacterial inhabitants in the sediment at almost seven miles deep in the Mariana Trench.
The researchers found an unexpected abundance of microbial life that they conclude come to reside at great ocean depths because gravitation and seismic activity cause the remains of deceased fish, algae, and other microbes to find the lowest depths.
As expected, the researchers found very few large life forms in the Mariana Trench.
The examination of any life form at great depths requires an in situ evaluation because the pressures and temperatures at such depths cannot be maintained in the transport of life forms from the deepest oceans to the surface.
The researchers found similar bacterial life to be abundant in the Japan Trench that is approximately 5.6 miles deep, and are planning a dive in the world's second deepest trench, the 6.7 mile deep Kermadec-Tonga Trench near Fiji in the Pacific later in 2013.
Ronnie Glud (Nordic Center for Earth Evolution at the University of Southern Denmark) and researchers from Germany (HGF-MPG Research Group on Deep-Sea Ecology and Technology of the Max Planck Institute in Bremen and Alfred Wegener Institute in Bremerhaven), Japan (Japan Agency for Marine-Earth Science and Technology), Scotland (Scottish Association for Marine Science) and Denmark (University of Copenhagen) are responsible for the three years of work that went into this research.