Participant Interview:
Julie Huber
Microbiology Graduate Student
University of Washington

Jeff: This is the third year of your thesis. Could you discuss what topic you're researching?
Julie: I'm working on projects with Dave Butterfield to understand the relationship between the chemistry and microbiology (archaea and bacteria) at diffuse flow vents. We think diffuse vents are an indicator of life in the subsurface (beneath the ocean crust). Since we don't have good drilling methods yet, fluids coming out of the sea floor are the only subsurface expression we have. If the chemistry changes, then we expect selection for different microbes. In the long run our goal is to map out what the subsurface at Axial might look like microbially and chemically.

Jeff: What kind of conclusions can you draw so far?
Julie: We've found that as long as the vent fluids are warmer than background sea water levels, the hotter the fluids are, the less microbes we find. I'm using molecular methods to separate out particle-attached (microbes attached to rock, etc.) vs. free-living (floating in water) populations. We think that to live in the subsurface its advantageous to make a living by attaching to particles and forming bio-films (sticking to things by secreting stuff). Otherwise you're just going to get swept out in rising vent fluids. I'm working on a '98 and '99 study of partice-attached and free-living microbes at Marker 33 that's almost done. That will be my Masters. After that, I'll continue. There's a lot to do out here.

Jeff: What microbes do you typically find living in the subsurface?
Julie: We usually isolate archaea, which are mostly anaerobic. They probably come from deep, hot subsurface areas. Every once in a while we get bacteria, which are mostly aerobic. So, we think that there are oxygenated pockets (micro-habitats) in the subsurface that have a lot of circulation with seawater. That's how these micro-habitats are getting their oxygen.

Jeff: What do you find most exciting about your research?
Julie: I really like playing with the bugs. It's hands-on and I like the fact that they grow at such high temperatures (sometimes over 100øC). It's just cool. I mean, we cook the bugs and the bugs just say, "Yea!" Actually, I think the coolest thing about this is that it's an under-water volcano. It was so neat the first year we came out here and saw all the new lava and I was just thinking, Wow, that's not even a year old.

Julie Huber with tubes full of "bugs" to "cook"
(read the full story).

Vents Program's fluid sampler at Marker 33 used for collecting many of the samples for both chemists and biologists.