I woke up at 6 a.m. this morning eager to see if we would have a chance to dive. I had slept quite well, which was a clear indication that the seas had come down quite a bit. Still, during repeated checks over the coming hours, the team decided conditions weren’t yet safe. Then, at 1:30 p.m., we finally got the go ahead and everyone jumped into action.
Lisa quickly got to work getting her Large Volume Water Sampler ready to launch. She put in a number of sterile filters to capture microbes, then primed the system with ultra clean water so none of the tubing would collapse under the great pressure of the sea. After a very smooth launch, we were on the bottom by 5 p.m., approximately 1 mile beneath the surface.
Our one and only target was Marker 113, which doesn’t sound very exciting, but is one of my favorite spots at Axial. It sits atop a lava pillar and is completely covered with tubeworms, limpets, palm worms, and scale worms. They are all living amidst the diffuse shimmery fluid flow that contains the essential nutrients needed both by the microbes those larger animals depend on to produce their food, and the microbes living within the seafloor that we’re here to study.
We landed almost right on top of our mark and quickly got down to the business of sampling. We knew from previous years to expect temperatures around 25 to 30°C (77-86°F). That’s a range that supports the microbes and viruses we’re after, so we used the ROPOS temperature probe to poke around for just the right spot.
After re-positioning the sub a few times, we found a great shimmery spot with proper temperatures. We then took out Lisa’s sampler intake, equipped with another temperature probe, placed it in the vent, and started. Then we pumped and pumped and pumped, for 2 hours.
During that time, we enjoyed the vent scenery, and monitored that temperature probe. Lisa needs a ton of water because viruses are so very small, and we need so many to run planned experiments. We pumped and filtered close to 200 liters (that’s 52 gallons!) of vent fluid through the filters and into the sample bags.
We’ll be using this large sample in a variety of ways. Lisa will concentrate the viruses in the water and combine those with microbes captured on the intake filters to study what effects the viruses have when they infect the microbial cells. She’ll also analyze the genetic sequences of the microbes and viruses to figure out who’s down there, among other goals.
Once all the pumping was done, we used Giora’s Isobaric Gas Tight Samplers (IGTS) to get samples of the vent water that supports the microbes and viruses to analyze its chemistry.
That Sweet Stink
The IGTS samples were collected in short order and we were on our way back up. The minute ROPOS was safely on deck we knew the dive was a success because the whole vehicle reeked of the rotten egg scent of hydrogen sulfide that characterizes vent fluids. Some people hate the smell, but I love it, because it means we got a good sample that is probably chock full of microbes and viruses. It’s the smell of life.
As I type this, Lisa, Caroline, and Giora are processing samples. The rest of the team is getting ready for the next dive, which should launch by midnight. This time we’ll be using Dave’s Hydrothermal Fluid and Particle Sampler. The weather is currently should be OK for a couple more dives, but the forecast says it will be rough again soon. Stay tuned.