There are few known biologically-active environments that are as hostile as those which surround the deep-sea hydrothermal vents studied by Dr. Anna-Louis Reysenbach, a member of the Portland State biology faculty.
A specialist in microbial ecology, Reysenbach and her team study the unique habitat represented by hydrothermal vents off the coast of Oregon by using a deep-sea submarine known as Alvin. In particular, the team’s research focuses on the resilient life forms that live near the vents.
“This is a frontier of science,” Reysenbach said. “We know that we’re going to find brand new, unusual organisms that nobody knew existed. That’s a huge genetic potential. If you’ve got so many novel genes, there’s a possibility for novel discoveries.”
Traditional notions in the ecological community hold that the sun is the foundational source of energy for life on earth. However, at depths of about two kilometers below the surface of the ocean—sometimes as deep as five kilometers—darkness is so absolute that a number of species do not even develop eyes. As a result, organisms must rely on an alternative source of energy. The hydrothermal vent is a prime candidate.
The vents are roughly cylindrical in shape and resemble an underwater volcano. The vent, which can grow at a rate of one foot per day, is porous rock formed by the precipitation of minerals as the super-heated water—upwards of 900 degrees Fahrenheit—spews from the fissure, and confronts the surrounding frigid marine environment.
The plumes of black smoke that are ejected by the vents are in fact minerals, notably sulfides, from the earth’s crust.
The significance of these microbes is not confined to circles of academic speculation. The atypical properties of these organisms suggest a number of interesting possibilities, ranging as far as medical and nanotechnology, which is engineering at a microscopic level.
For example, the presence of an abnormal flexibility in the cell walls of these microbes could have great implications in the nanotechnological community if the material could be reproduced, synthetically or otherwise. Additionally, the gravitation of these microbes toward toxins and acidity could prove useful in the clearing and draining of acid mines, where harmful chemicals and metals, like arsenic, pose a hazard.
For Reysenbach’s research forays into this field, she has received grants from both the National Science Foundation and NASA.
According to PSU’s website, Reysenbach has also studied deep-sea vents in the Atlantic and Indian Oceans.
However, she admits that there remains a great deal of unknowns surrounding the organisms that inhabit these unique biomes.
“We can only describe about 1 percent of the organisms—microbes—that are in the environment,” she said.
How and when these microbes colonize these formations, the localization of populations and the prolificacy of certain species throughout the oceans are debatable, according to Reysenbach. The biggest question, however, is just how these organisms live so successfully in such a volatile climate. But, according to Reysenbach, it appears they do it with skill.
“They don’t survive [there],” Reysenbach said. “They thrive.”