Kevin Portune typically studies harmful algal blooms in the mid-Atlantic region of the United States. While aboard Atlantis, however, he maintains two pieces of critical equipment for studying Alvinella
pompejana, the Pompeii worm. Alvinella is believed to be the most heat-tolerant organism among the complex life forms, being able to withstand fluid temperatures up to 176 degrees Fahrenheit. Scientists owe that discovery to the two pieces of equipment that Kevin is maintaining. The first of these is a device known as the "Sipper."
In previous journals, we discussed what occupied most of Kevin's time during our transit to 9° north, namely setting up the Sipper, since it needs to be shipped in pieces to Atlantis. The Sipper is a caged cylinder about the size of a medium-sized trash barrel attached by tubing and some wire to the sipper wand. The end of the wand contains a temperature probe and a tube for transporting water. Mounted inside the cage are spring-loaded syringes connected to a complex system of very thin tubes. This tubing also is connected to a pump, which is used to draw water through the tubing. All of this is wired into the interior of the submersible, so the firing of the syringes and the data from the temperature probe can be monitored by the scientists.
There can be no air in the Sipper's tubing system, otherwise you will not get a full water sample. Therefore, all of the connections must be checked to make sure that no air can enter the lines before Alvin descends. This task has occupied Kevin late every evening in preparation for the next day's dives.
Every dive of Extreme 2004 has utilized the Sipper to take water samples. Here's how the basic process works. The pilot identifies an Alvinella colony and picks up the Sipper's wand with Alvin's manipulator. The probe is then placed into a tube of the Alvinella colony. Immediately, scientists can begin measuring the temperature of the surrounding water using the temperature probe. Alvinella has been documented in a wide range of temperatures.
Scientist Michelle Phillips said, "We're interested in knowing the specifics about any worm that we work on. By documenting factors like the temperature now, it may help us later when we're trying to understand our data."
Documenting what temperature the worms came from may make for some interesting comparisons of worms from very different temperatures.
While the scientists are collecting the temperature data, they turn on the Sipper pump, which begins flushing the Sipper's tubing with water from inside the Alvinella colony. After a minute of flushing, one of the observers sends a message to the Sipper via a small laptop inside Alvin and a syringe is fired. The pilot can observe the firing through a camera focused on the Sipper. By flushing the system for a minute and observing the firing and filling of the syringe, the pilot and scientists can rest assured they received a good water sample.
The next step in the process involves the second piece of equipment that Kevin works on, nicknamed the Artie, after Arthur Sundberg, assistant director of marine operations at the University of Delaware's College of Marine Studies and the man who helped design and build it. This device consists of three cylinders mounted inside a milk crate and connected via tubing through a valve to a bag of preservation fluid called RNAlater. Each cylinder can be connected directly to the RNAlater bag by changing the position of the valve. So, once the temperature data has been collected and the water sample taken, the pilot will use the manipulator to gather a few Alvinella worms and deposit them into one of Artie's cylinders. The cylinder cap is then put on, which seals the chamber.
The next task is to preserve that worm and the associated bacteria with the RNAlater. Here's how that works: the RNAlater is housed in a bag in a closed cylinder. This bag is connected to the Artie via tubing. Once the cap is on the chamber, the pilot flips a switch, which begins to pump seawater into a separate bag in the RNAlater chamber. As the seawater bag fills (since it's in a closed container, it puts pressure on the RNAlater bag, forcing the RNAlater out the tubing and into the Artie chamer. Pretty clever, huh?
Now the scientists have temperature data, water samples, and Alvinella worms to study upon Alvin's return to the surface. Once on deck, the water samples are removed from the Sipper and processed by Charles Lee. "We're interested in the metals and sulfides present in the water. Once on deck, I take the water samples and perform analysis for iron and sulfur. I also add reagents to prevent oxidation in the samples. This way, we can conduct further analysis once we return the samples to our lab on shore."
The other interesting story that I've been following is that of Dr. Shannon Williamson, Dr. Astrid Schnetzer, and Shellie Bench. Shannon and Shellie are interested in marine viruses that are found in the hydrothermal vent system. Astrid is interested in small protists. They deploy a device called the Large Volume Water Sampler (LVWS). The reason I picked up on their story was that they had the misfortune of having two devices not work for their water collection -- on the same day! So, they declared December 3 as the "No Water Day!"
Today, however, they met with great success! They deployed the LVWS over the side, and then Alvin picked it up and put it into position over a diffuse water source. The LVWS is acoustically released, so after the pump is turned on and the on-board bags are filled with water, Atlantis sends a sound wave, which causes a float to release and the LVWS to begin its journey up to the surface. Atlantis retrieves it, much to the delight of Shannon, Shellie, and Astrid. Their filtering work begins before a night deployment of the CTD. But you'll have to wait until tomorrow to see those pictures.
One last note, Karen passed off her camera to Second Mate Craig Dickson in the Rigid Inflatable Boat. To see how wonderful those shots turned out, check out today's Neat Stuff!
