A team of researchers, led by Ronnie Glud of University of Southern Denmark discovered that a huge community of bacteria grows in depths of the Mariana Trench off the coast of the Pacific Ocean’s Mariana Islands. It was found that the organisms live at the densities ten times higher than shallower ocean floor at rim of trench.
The deepest point on entire seafloor is called The Challenger Deep and it is situated in Mariana Trench off the coast of the Pacific Ocean’s Mariana Islands. This point is 36000 feet or 7.8 miles below the surface of the ocean.
How was the research done?
In order to explore the ecosystem that exists ultra-deep, the international team of researchers sent the specially-designed 1300 pound robot in the depth of the Mariana Trench in 2010. This robot was facilitated with thin sensors which could enter into the seafloor sediments in order to measure organic consumption of oxygen. Because all living organisms consume oxygen while respiration, therefore it is possible to find out the amount of microorganisms living in an area by checking the tallies on what quantity of ambient oxygen is missing from the sediments.
The team of researchers used the device for sampling the sediments at two sites with depths of 35476 and 35488 feet. It was found that large quantity of oxygen consumption took place. This indicated that there were ten times more bacteria at the ultra-deep site than the shallower site which was sampled just for reference around 37 miles away, at a depth of merely 19626 feet.
What did the specially-designed 1300 pound robot explore?
The robot brought out an overall 21 sediment cores from these two deep sites. The sediment cores were kept for analysis in the lab. Even though a lot of microorganisms died after being brought out to the surface, but it confirmed the finding that cores from Mariana Trench were habitat to higher densities of bacterial cells than the ones which existed in the reference site.
Also, the video recording of the ocean floor was done by making use of the lights for illuminating the dark environment. It was also discovered that certain life forms which were larger than the bacteria on the top of the sediment, existed. It was determined that these life forms were Hirondellea gigas, a species of amphipods. Amphipods are the small crustaceans which are just less than one inch in terms of length.
Importance of the research
The finding of abundant bacterial life at such a depth is very surprising because it was believed that at such depths, not enough nutrients can be found. The Photosynthetic plankton can act as a nutrient base for almost all the ocean food chain, but even these planktons are unable to survive in lightless seafloor. But this research has amused the scientists because ultra-deep trench was found to be the abode of so much bacterial activity than the shallower reference site just nearby.
Since 2010 exploration, the team of researchers has also sent this robot to sample Japan Trench which is roughly 29500 feet deep. The researchers now plan to sample the Kermadec-Tonga Trench which is 35430 feet deep.