"The abyss turns out to be riddled with mineral, biological and intellectual riches and will probably divulge more surprises in the decades ahead."
--New York Times, Nov. 16, 1993
Underwater volcanoes and vents are providing a "hotbed" of research in every sense of the word for UW researchers. These surreal features of the ocean floor are yielding exotic new life forms that have potentially very valuable commercial properties, and at the same time they may also shed light on the origins of life on earth. The vents where these organisms flourish have rich deposits of precious minerals that may be exploited in the future. Meanwhile, new underwater observing platforms are being installed to monitor volcanoes more than a mile and a half below the surface of the Pacific Ocean off the coast of Washington State.
It is an environment as strange as any alien planet in a science fiction story--perhaps even stranger, and it actually exists on our planet, under the ocean. Deep in the icy darkness, where the surrounding water is a few degrees above freezing, under crushing pressure, the process begins: seawater trickles down through cracks in the earth's crust to depths reaching several miles into the mantle. There, the seawater is heated by magma and is forced upward as it expands, leaching out minerals as it goes. Finally, the hot, mineral-laden water spews out into the ocean through chimneys of rock, forming deposits of minerals and metals such as zinc, copper, silver, and gold. The waters nurture an oasis of exotic, heat-loving bacteria of unusual biochemical make-up, and colonies of bright red tube worms.
In 1983, John A. Baross and Jody W. Deming reported in the scientific journal Nature that they had grown some of these heat-loving bacteria, or "thermophiles," at about 250° C, or about 482° F. That report stirred up quite a storm of controversy, since microorganisms have been thought to be capable of existing only between, roughly, the freezing and boiling points of water—from 0° C to 100° C (32° F to 212° F). At that time, Baross was at Oregon State University and Deming, at Johns Hopkins University. Today, they both continue their work as oceanography professors at the UW.
In 1988, the two researchers reported results of an expedition to a segment of the Juan de Fuca Ridge under the Pacific Ocean, about 250 miles off the Washington coast. They collected samples using the deep-diving vehicle named "Alvin." From those samples, Baross isolated quantities of archaebacteria, the most ancient cellular life forms. Biologists divide life into three kingdoms: archaebacteria, or ancient microorganisms; eubacteria, or common bacteria; and eukaryotes, all other organisms. Most of the heat-loving organisms are archaebacteria.
Baross was the first scientist to suggest that all life on earth today evolved from the kind of high-temperature microorganisms thriving in deep-sea hydrothermal vents. He believes these hot springs provided the ideal setting in which life could form, safely protected from the barrage of meteors and radiation that pummeled the surface of earth in its infancy. "The subsurface environment seems like the stable womb of the early earth," says Baross.
Scientists searching in many locations around the globe, drilling beneath both land and sea, are uncovering evidence that there may be huge colonies of such ancient microorganisms living deep within the earth. In some cases, these life forms may have been cut off from all other life on earth for millions of years, even since before the age of the dinosaurs. The concept is challenging conventional theories of evolution and opening new lines of investigation. For example, the theory suggests new places to seek microbial fossils; it poses new candidates for gas-releasing organisms that could have modified the earth's atmosphere in its early stages of development, as well as new biological agents that could have helped make oil and gas deposits.
The unusual biochemistry of thermophiles has spurred interest among academic and industrial circles in potential research and commercial applications. Companies are scrambling to isolate the high-temperature enzymes that are part of the thermophiles' normal biological processes, for example breaking down nutrients and synthesizing biochemicals. More than 14 such high-temperature enzymes have been isolated. In the future, these "extremozymes" may aid in developing new chemical and pharmaceutical products, high-temperature chemical processing techniques, and novel strategies for breaking down toxic wastes. For example, a natural enzyme from the heat-loving bacterium Thermus aquaticus, called Taq polymerase, has become a key component of the polymerase chain reaction, the workhorse of modern molecular biology.
Now, with support from the National Science Foundation, oceanographers from the UW along with six other institutions will establish the first permanent observatories to monitor the sea-floor volcanoes off the coast of Washington at the Juan de Fuca Ridge. A fundamental goal of the work will be to gain a greater understanding about how these sea-floor volcanoes and vents can sustain life independent of sunlight, explains UW oceanography professor John Delaney, co-leader of the collaborative effort. The fact that these heat-loving organisms use entirely different biochemical mechanisms for extracting energy from their environment has "profound implications" for those studying the origins of life on earth and the possibility of extraterrestrial life, he notes.
A network of instruments and sensors will be installed to collect information around the sea-floor vents and volcanoes, much like the network of instruments that surrounds Mount St. Helens. In the past, expeditions to the undersea volcanoes have been limited due to the cost and logistical constraints of deep submarine dives. Having a permanent installation will enable scientists to study how the ridge vents change over time; to determine the size and frequency of undersea volcanic eruptions and monitor how magma moves from the crust to the sea floor; and to study how biological communities develop around the vents and beneath the sea floor.