On Wednesday, pilot Bob Waters, microbiologist KT Scott, and postdoc Nuria Fernandez Gonzalez headed down to the vents to find the Vent-SID microbial incubator that we’d deployed the day before. A large ray swung by to wish them a successful dive, and they watched it swim around the sub through the viewports before starting their descent.
At the bottom, the divers sent the Vent-SID back to the surface and collected several samples of vent fluids, some tube worms, and chunks of a black-smoker vent structure. A hydraulic line on one of Alvin’s manipulator arms got nicked at the black smoker, so the sub surfaced a little earlier than planned, but the Alvin group got everything into shape for the next day’s dive.
The Vent-SID’s final deployment was our most successful yet. It returned to the surface full of samples that had incubated on the seafloor. The instrument is designed to measure the rates at which microbes perform certain biochemical processes under the conditions of their natural environments at the vents. Microbes are the base of the food chain at hydrothermal vents, so understanding how they work is an important part of understanding the whole vent ecosystem.
The Vent-SID, the latest version of the SID family of instruments developed by Craig Taylor and engineers at WHOI, works by pulling vent fluids rich with microbes into its insulated glass incubation chambers and keeping them at the temperature of the vent, something that has never been done before. At regular intervals over the next few hours, the instrument takes samples of the fluid in the chamber and preserves them, so the researchers can determine what microbes are present and what their activities are. These measurements will tell the scientists how productive vent ecosystems are and help them get a better idea of their importance for biogeochemical cycling in the ocean.
First-time Alvin diver Nuria has been hard at work throughout the cruise preparing the Vent-SID for its deployments and processing samples. When she returned to the ship after her dive, she was crowned the Vent-SID Queen with a garland of sample bags and a tubing necklace before she received her ice-bucket initiation.
In local sports news: The all-hands ping-pong tournament has been heating up over the last few days. Alas, the two top-performing scientists on board, Jeff Seewald and Stefan Sievert, were eliminated in the semifinals. They now join those of us (ahem) battling for third place overall in the consolation bracket. Tomorrow morning, ordinary seaman Ronnie Whims faces bosun Patrick Hennessy in the championship match.