They study Riftia pachyptila, giant tubeworms that live at the hydrothermal vents on the ocean floor. Here at the East Pacific Rise, they hope to gather enough samples to add to their understanding of the proteome of Riftia. The proteome is all the proteins that combine in the bacteria that live in and depend on Riftia. It's a symbiotic relationship, which means that they can't live without Riftia and Riftia can't live without them. This makes the bacteria symbionts.
So that's the vocabulary. And here on the ship R/V Atlantis, the study begins with the sample of Riftia brought up by Alvin. Horst and Steffi bring their samples to the hydro lab. Although they try to work on them right away, they also have a high-pressure tank where the Riftia can be kept alive until it is time to begin studying them. On the day that I visit the lab, a vent crab brought up accidentally by Alvin also is living in the tank. Here's what Horst and Steffi do with the worms:
1. Horst or Steffi removes the tubeworms from the tubes that they live in. The tube is made of a tough, natural material called chitin (pronounced "kite-in").
2. Steffi splits the worms open lengthwise, dissecting them to remove the trophosomes. This is what is inside the worm. For the most part, trophosomes are dark purplish-red, globby strands. The trophosomes have a distinctive color depending on what element they were most exposed to: black indicates a lack of hydrogen sulfide. Yellow indicates lots of hydrogen sulfide. Green is somewhere in between.
3. The trophosomes are moved to homogenizing vials to separate out large blood vessels and to give the substance a smoother consistency. Horst fills the vials with argon gas to prevent too much air from getting in. These vials have a liquid in the bottom that Steffi tells me is a homogenizing agent called Percoll, designed to keep the liquid from separating. Next the trophosome fluid is mashed in the tube with a glass pestle. This destroys the host cells but leaves the bacteria intact.
4. The homogenized material, a mashy liquid, is strained through a screen to remove solids and any remaining blood vessels.
5. Steffi places the closed vials in a centrifuge and spins them for 10 minutes to separate the bacteria from the host cells.
6. The bacteria can now be sucked out with a syringe.
7. Finally, the bacteria are extracted, washed, and counted under a microscope.
"This is the easiest place to screw up," says Steffi.
Horst replies, "You can screw up anyplace in the process, but it's pretty easy to do here."
After all this? Yes, they tell me. It's easy to count wrong, and that throws off your research. What they're hoping to learn is exactly what proteins -- and how many of them -- are found inside Riftia.
Horst and Steffi's work is just one example of research begun on the ship that will carry on long after the scientists go home. The goal for many is to gather enough samples -- enough vials, enough slides, enough data -- to work with once they get back to their labs.
As for me, I'm gathering material of my own: experiences that transfer into words and pictures for me to include in future books. I'm also getting tons of new understanding of the scientific process, of course, but something else, too. The more I sit with, observe, or chase around the scientists working to understand the vents, the better I understand the vents myself.
But I also understand, more and more, what it is like to study one aspect of the vents while others around you study theirs. It's interesting to see how it all adds up. How does it get divided, this big subject, among lots of people? Dr. Craig Cary tells me there are 20 to 30 groups like ours researching 9º North, plus others studying vent areas elsewhere, and still more studying extremophiles in places like Antarctica.
Horst Felbeck and Dr. Eric DeChaine are among the scientists on this ship whose research isn't focused only here. Eric's work on extreme environments has taken him to the tops of the Rocky Mountains. You can find out more about his work in Mike's journal today.