Scientists discover life 8,000 feet below the ocean floor

Friday, December 11, 2015 by: David Gutierrez, staff writer
Tags: ocean floor, extremophiles, living ecosystems

---

(NaturalNews) Life has been discovered in an environment with no oxygen, no light and almost no nutrients -- 8,000 feet below the surface of the ocean floor. The findings came from the International Ocean Discovery Program (IODP) and were presented at the America Geophysical Union 2014 Fall Meeting.

The samples were collected from the deepest ocean drilling expedition in history. Even in such an extreme environment, the researchers found single-celled microbes with incredibly slow metabolisms that essentially feed on coal.

"We keep looking for life, and we keep finding it, and it keeps surprising us as to what it appears to be capable of," said researcher Elizabeth Trembath-Reichert, of the California Institute of Technology.

Completely hostile environment

In 2012, researchers sunk a drill to the ocean floor off the coast of Japan's Shimokita Peninsula -- a depth of more than 1,000 m (3,000 ft). They then drilled 2,446 m (8,024 ft) into the bedrock, further than had ever been drilled before. The environment they penetrated -- a deep sea coal bed -- is thought to be completely lightless and anaerobic (lacking in oxygen). Yet, even though nearly all forms of life require either light, oxygen or both, and even though there is nearly no water or organic material in the depths sampled, life was still found.

In order to analyze the mysterious organisms, the researchers tried feeding them various chemical compounds to figure out what they might be eating.

"We chose these coal beds because we knew there was carbon, and we knew that this carbon was about as tasty to eat, when it comes to coal, as you could get for microbes, " Trembath-Reichert said. "The thought was that while there are some microbes that can eat compounds in coal directly, there may be smaller organic compounds -- methane and other types of hydrocarbons -- sourced from the coal that the microbes could eat as well."

The experiments showed that the organisms were in fact digesting methyl compounds. Perhaps due to their sparse environments, they have incredibly slow metabolisms -- using the absolute minimum amount of energy needed to keep themselves alive.

Discovery raises new questions, possibilities

The researchers next hope to discover how diverse the deep sea coal bed ecosystem is -- does it contain a wide variety of species, or just a handful? They also hope to discover how life managed to colonize such a remote and hostile biological niche.

"Were these microbes just in a swamp, and loving life in a swamp, because there is all sorts of carbon available, oxygen, organic matter... and then that gets buried?" Trembath-Reichert said, referring to the terrestrial habitats that, over the span of geological time, eventually turned into oceanic coal deposits.

"It could be that they didn't get a chance to escape -- they couldn't exactly walk out. So is it that they were there to begin with and then they could maintain life? Or were they like microbes that were able to travel down to those depths from the surface?"

The discovery of the organisms also calls into question the conventional wisdom about the earth's carbon cycle. The deep-sea microbes were discovered to digest hydrocarbons and turn them into methane, and thereby contribute to emitting greenhouse gases in the atmosphere. This may cause researchers to reassess the role played by the ocean in regulating the planet's climate.

Research into "extremophiles" -- organisms that live in extreme habitats -- is also considered to have significant implications for the search for life on other planets. Each discovery pushes the boundaries for what types of planets could potentially support life.

In 2012, scientists discovered life in the lightless, freezing waters of an Antarctic lake covered by more than 60 feet of ice, six times saltier than sea water and with levels of nitric oxide high enough to poison nearly all known life forms.

Sources for this article include:

http://www.bbc.com

http://www.naturalnews.com