Life discovered in deep ocean bed

Chennai: Throwing light on the ever-mysterious ocean bed, scientists have discovered life in an ‘inhospitable’ environment, where temperatures touched 120 degrees Celsius.

According to the international team of scientists, including those from the University of Rhode Island in the US, the diversity of microbes below the seafloor is as rich as on Earth’s surface.

The research published in the journal Science on Friday, discovered 40,000 different types of microorganisms from core samples from 40 sites around the globe.

“Water boils on the (Earth’s) surface at 100 degrees Celsius, and we found organisms living in sediments at 120 degrees Celsius”, said Arthur Spivack, a co-author of the study from the University of Rhode Island.

In the current study, the scientists assessed samples from the Nankai Trough off the coast of Japan, where the deep-sea scientific vessel, Chinkyu, drilled a hole 1,180 metres deep to reach sediments at 120 degrees Celsius.

They said sediments that lie deep below the ocean floor are harsh habitats with temperature and pressure steadily increasing with depth, and the energy supply for life forms becoming increasingly scarce. According to the study, it has only been known for about 30 years that, in spite of these conditions, microorganisms do inhabit the seabed at depths of several kilometers.

“Surprisingly, the microbial population density collapsed at a temperature of only about 45 degrees”, said Fumio Inagaki, another co-author of the study from Japan Agency for Marine-Earth Science and Technology (JAMSTEC).

“It is fascinating- in the high-temperature ocean floor, there are broad depth intervals that are almost lifeless. But then we were able to detect cells and microbial activity again in deeper, even hotter zones- up to a temperature of 120 degrees”, Inagaki added.


NT Bureau