Minion glasses

Just as soon as we finished sorting all our larvae from the MOCNESS, another gear deployment promised to bring us more. This time it was the autonomous underwater vehicle Sentry, which belongs to Woods Hole Oceanographic Institution in Massachusetts. Woods Hole is in my opinion the best oceanographic institute in the world, and to put it simply, they have all the best toys. Ships, ROVs, AUVs, submersibles - Woods Hole has it all. The AUV Sentry is an amazing vehicle, and the team that keeps her running really knows their stuff. They're creative, intelligent, skilled engineers, and they're pretty agreeable people too. I have only positive things to say about Sentry.

Sentry with the plankton pumps attached.
Is anyone else thinking Despicable Me?

Anyway, autonomous vehicles haven't traditionally been used to collect plankton from the deep sea. The capability to do so is a new innovation. I remember being on a conference call in my adviser's office in Oregon a year and a half ago and overhearing some discussion of putting plankton pumps on Sentry. My adviser wondered if it was even possible and asked the Woods Hole team to investigate. Well, investigate they did, because now, Sentry is equipped with two fully-functional plankton pumps, one on each side. The pumps were invented by a team at Woods Hole, and I've got to say, I'm deeply impressed. Each pump has a swinging door on the front that can open and close at pre-programmed times, thereby controlling the depth at which plankton are captured. Water is filtered through fine mesh in a long tube, and any remaining particles are collected at the back end. One common problem in actively pumping water is that the larvae get smashed against the filter, but the Woods Hole team was able to keep the water at the end of the tube moving so no larvae get squished. So cool!

A few nights ago was Sentry's first real deployment with the pumps, so we weren't even sure our sampling scheme would work. In the end, it proved to be a highly successful deployment, because we spent all of this morning and part of the afternoon sorting larvae. Got to admit, it was a lot of fun to skip down the hallway and inform the Sentry team that their devices had worked. A couple of the guys insisted on seeing their precious larval catch, so we showed them a few under the microscope.

One final note: the plankton pumps still don't have an official name, so after the larvae were all
sorted, we spent a good hour or two brainstorming titles. Our suggestions ranged from clever to cheesy to downright stupid, but Carl, the leader of the Sentry team, seemed to like two of our ideas. I'll keep you posted if they decide on a name!