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."