Rock-eating microbes survive in deep ocean off Peru
Way down deep in the
ocean off the coast of Peru, in the rocks that form the sea floor,
live bacteria that don’t need sunlight, don’t need carbon dioxide,
don’t need oxygen. These microbes subsist by eating the very rocks
they call home.

Researchers from the Ocean Drilling Program (ODP) have
embarked aboard the world’s largest scientific drillship on a voyage
to understand the abundance and diversity of these microbes and the
environments in which they live.

“The implications of this mission are exciting,” said Jack
Baldauf, deputy director of ODP at Texas A&M University, science
operator for the program. “Earlier voyages have found specimens of
these bacteria at depths of up to 800 meters below the sea floor,
and we estimate that they may number between 10 and 30 percent of
the Earth’s biota. That means that the biosphere is larger than
previously thought – it doesn’t just stop at the sea floor.”

Other expeditions have obtained samples of these bacteria, but
little is known as yet about their real numbers, their diversity, or
their role in the biogeochemistry of the oceans.

“It’s like walking into a tropical rainforest for the first
time and beginning to identify and count the birds,” said Tom
Davies, manager of ODP science operations at Texas A&M.
“This type of microbiology is a new science field for ODP. Such
research raises questions about the presence of life in extreme
environments on this planet and possibly other planets.”

The drillship JOIDES Resolution is scheduled to depart for
ODP Leg 201 Feb. 1 from San Diego, Calif. to core sites in the eastern
equatorial and southeast Pacific. Cores containing microbes will be
sampled from previously drilled sites, chosen to represent
different subsurface environments, such as methane rich and normal
oceanic environments.

Jay Miller is the ODP project manager and Texas A&M staff
scientist for leg 201. Co-chief scientists are Steven D’Hondt of
the University of Rhode Island and Bo Jorgensen of the Max Planck
Institute for Marine Microbiology in Germany.

The Joint Oceanographic Institutions, Inc. (JOI) manages ODP
with advice from Joint Oceanographic Institutes for Deep Earth
Sampling (JOIDES). JOI consists of a consortium of major US
institutions with marine science programs. The National Science
Foundation (NSF), a U.S. government agency, supplies 65 percent of
ODP’s $46 million annual budget, while 21 international partners
contribute the remaining 35 percent of the required funding.

Texas A&M is one of two principal ODP contractors. It runs
the research ship and hosts one of four repositories for deep-sea
ocean core specimens. The ODP’s JOIDES Resolution mounts six
expeditions a year, each lasting about two months and targeting
sites around the globe, chosen with specific scientific goals in
mind. The ship houses 13,000 square feet of laboratory space,
including 13 different labs for studies ranging from
microbiology to geophysics. Typically an international team of 28
scientists participates in each voyage.

Lamont Doherty Earth Observatory (LDEO) is the other principal
ODP contractor. It is responsible for downhole logging operations
and management of the site survey data base.

“ODP is uniquely positioned to sample one of the least known
and potentially strangest ecosystems on Earth – the microbial
biosphere of deep marine sediments and the oceanic crust,” Baldauf
said. “The growing international interest in the subsurface
biosphere is driven by many factors, not the least of which is sheer
fascination with the nature of life on the margin of existence.”

Contact: Judith White
Texas A&M University