URI oceanographer to lead return visit to least inhabited place on Earth

September 30, 2010

NARRAGANSETT, R.I. - September 30, 2010 - Four University of Rhode Island oceanographers depart next week for an international research expedition to the middle of the South Pacific Gyre - an area that is as far from any continent as is possible to go on Earth's surface - to look for evidence of life far beneath the seafloor.

The expedition is a follow-up to a 2006/2007 visit to the same sites where the scientists found so few organisms living in the shallow sediment that this region may be the least inhabited marine sediment ever explored. This year's nine-week expedition seeks to look for evidence of life in the older, deeper sediment and "the basaltic basement."

"We'll be drilling holes in the South Pacific seafloor through the entire sediment column and into the basaltic basement to look for evidence of life and habitability in one of the most energetically challenging environments on Earth," said Steven D'Hondt, a URI oceanography professor who will lead the expedition.

"We found very little evidence of life in the near-surface sediment, so now we're going to drill deep to see what communities are like in even older sediment and rock that's even lower in food," he added.

The team will depart from Tahiti on Oct. 9 aboard the 469-foot JOIDES Resolution, a drilling shipping owned by the Integrated Ocean Drilling Program. The sediment cores they recover will then be analyzed for their chemistry and microbial communities to detect evidence of life.

"Since we found very little evidence of life in the surface sediments, there will probably be even less below," D'Hondt said.

The research team includes 100 scientists, technicians and crew from a dozen countries around the world. In addition to D'Hondt, other scientists participating from the URI Graduate School of Oceanography include David Smith, Arthur Spivack and Dennis Graham.

Gyres are semi-still areas in the middle of the oceans where there is little wind, little current, and very little upwelling of deep water, so the water is clear and contains few nutrients. The South Pacific Gyre is the largest of Earth's gyres, encompassing an area twice the size of North America. D'Hondt describes its center as "the deadest spot in the ocean."

Because the region is so far from terrestrial sources of sediment and so few organisms live in its water, its sediment accumulates extraordinarily slowly - as few as 8 centimeters per million years. D'Hondt said that the burial rate of organic matter was so low in the sediment that the principal food source for the microorganisms living there may be hydrogen released by the radioactive splitting of water due to the natural decay of elements in the sediment.

A main objective of the expedition is to test whether microbial communities can be sustained by this process.

"We don't know anything about life there in this deepest, oldest sediment," said D'Hondt. "It could tell us about the possibility of life elsewhere. If organisms can survive there, then perhaps they can be supported by the same processes on Mars or Jupiter."

It is also possible that some of the microbes they find may have applications that could ultimately benefit humans.
The research expedition is funded by the Integrated Ocean Drilling Program, an international scientific program that is co-sponsored by the U.S. National Science Foundation.

University of Rhode Island

Related Microbial Communities Articles from Brightsurf:

Microbial diversity below seafloor is as rich as on Earth's surface
For the first time, researchers have mapped the biological diversity of marine sediment, one of Earth's largest global biomes.

A new assembler for decoding genomes of microbial communities developed
The metaFlye assembler is designed to assemble DNA samples from microbial communities.

Princeton scientists explaining how diverse species coexist in microbial communities
In their paper appearing September 11, 2020 in the journal eLife, Princeton researchers Amir Erez, Jaime Lopez, Ned Wingreen and colleagues use mathematical modeling to explore how species diversity in a bacterial community is affected when the nutrients the microbes depend upon are only seasonally available.

Social distancing and microbial health
Social distancing is a key component of the expert-recommended strategy to reduce the spread of COVID-19.

Fish farming alters microbial communities, and reduces nitrate levels in pond ecosystems
The N and P fractions and water environmental factors influenced the microbial community structure and diversity in pond ecosystems.

Microbial cyborgs: Bacteria supplying power
Electronic devices are still made of lifeless materials. One day, however, 'microbial cyborgs' might be used in fuel cells, biosensors, or bioreactors.

Minimum energy requirements for microbial communities to live predicted
A microbial community is a complex, dynamic system composed of hundreds of species and their interactions, they are found in oceans, soil, animal guts and plant roots.

To reverse engineer dynamics of microbial communities, researchers construct their own
Scientific and public appreciation for microbes -- and the key role their communal actions play in environmental health, food production, and human wellness -- has grown in recent years.

It takes more than two to tango: Microbial communities influence animal sex and reproduction
It is an awkward idea, but a couple's ability to have kids may partly depend on who else is present.

Novel study underscores microbial individuality
A single drop of seawater can contain a wide representation of ocean microbes from around the world -- revealing novel insights into the ecology, evolution and biotechnology potential of the global microbiome.

Read More: Microbial Communities News and Microbial Communities Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.