Contact: Terry Collins: 1-416-538-8712; or Diana Kenney, MBL: 508-289-7139;

The Deep Carbon Observatory (DCO), a $500 million, 10-year international program that aims to reveal the quantity, movements, forms and origins of carbon inside our planet, has released its first major product after three years of inquiry: the volume Carbon on Earth.

Mitchell Sogin, director of the MBL’s Bay Paul Center for Comparative Molecular Biology and Evolution, co-chairs the DCO’s Deep Life Directorate. This group is discovering and describing the microbes and viruses that live in the deep ocean and beneath the ocean floor, and how they interact with deep carbon cycles. Guiding questions include:

* What’s down there?

* Do different geological environments host different populations of microbes and viruses?

* How do they adapt to extreme environmental conditions in order to survive?

* How does biological carbon link to the slower deep cycle, and is biologically processed carbon represented in deep-Earth reservoirs?

* Did deep biochemistry play a central role in life’s origins?

The variety of bacterial life at extreme high-pressure depths worldwide constitutes a subterranean “Galapagos,” DCO scientists say, adding that such subsurface life comprises a large portion of Earth’s total biomass — estimated in the late 1990s to be a third to a half of all life, though that figure is now considered high.

DNA has unearthed a marvel of diversity among deep single-celled micro-organisms, notably Archaea. And deep fungi-organisms with complex cell structures (eukaryotes) in the marine subsurface, have been a scientific surprise.

“Given the extraordinarily low rates of respiration, subsurface microbes must reproduce very slowly, if at all,” says Deep Life Directorate member Steven D’Hondt of the University of Rhode Island. “They take at least hundreds to thousands of years to reproduce and it’s conceivable that they live without dividing for millions to tens of millions of years,” he says. Still to be determined, Dr. D’Hondt notes, is the extent to which these organisms are “microbial zombies, incapable of being revived to a normal state.”

Sogin and MBL scientist Julie Huber, a microbial oceanographer who is also involved with the Deep Life Directorate, are this week attending the Deep Carbon Observatory’s International Science Meeting at the National Academy of Sciences in Washington, DC.


While we know approximately the thickness of Earth’s layers, the quantities of carbon below the surface in each layer remain a mystery. In fact, even the estimates of the carbon in the crust are quite uncertain. Fluxes between the layers complicate the mystery and the quest of the Deep Carbon Observatory. Credit: Deep Carbon Observatory

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