2002 Annual Science Report
University of Washington Reporting | JUL 2001 – JUN 2002
Sub-Seafloor Hydrothermal Vent Microbial Communities
Our research focuses on identifying unique sub-seafloor microbes and using them to model the sub-seafloor environment on earth, with implications for understanding life beneath the surface on other planets and moons.
In the last year, we completed our fourth field season at Axial Volcano, continuing our collaborative time series work at this young unsedimented seamount. The bulk of the first three years of this time series work has either been published, is in press, or is in preparation. Having such a distinctive data set has allowed us to carefully examine the environment beneath the seafloor. Using molecular methods, we have identified unique groups of both Archaea and bacteria that appear indigenous to the sub-seafloor, and we have followed these groups over three years. It is apparent that the incidence of these microbes can be correlated with pinpoint thermal and chemical changes at the vent, as well as with the evolution of the vent over time. We also use culturing methods, which allow us to ground truth our molecular work; those results indicate that the sub-seafloor at new eruption sites continues to support a hyperthermophilic community, even years following the disturbance.
We have begun to quantify these organisms, and this enumeration will be a key aspect of our future work. Additionally, we have isolated and begun to characterize a number of novel sub-seafloor microbes that exhibit hypothesized sub-seafloor characteristics, such as autotrophy and the ability to form biofilms. This year we will begin a new field program to obtain fluids from within the crust using a novel sampling device that will allow us access to previously unsampled fluids at older sedimented seamounts. This will be an excellent comparison with our samples from Axial Volcano, allowing us to further understand the connection between the geochemical setting and the microbial community in the sub-seafloor.
PROJECT MEMBERS:John Baross
RELATED OBJECTIVES:Objective 6.0
Define how ecophysiological processes structure microbial communities, influence their adaptation and evolution, and affect their detection on other planets.
Identify the environmental limits for life by examining biological adaptations to extremes in environmental conditions.