By Gabriela Hogue
Today I had the privilege of working with Mike Gray from USGS. He needed help removing his experiment from the lander that we would be retrieving. The experiment consisted of 3 plates, each with a hole drilled in the middle, attached together using a threaded nylon rod. The rod was attached to the lander using zip ties and gardener’s tape. Each plate is made of a different material; hard sandstone, steel, and Key West Limestone. There were 4 of these rods, with 3 plates each attached to the lander.
The thought is that bacteria should grow on each plate before anything else colonizes them. This should mimic the colonization that happens within the canyon. The canyons are made up of compressed mud, which is why one of the plates is hard sandstone. The steel plate is thought to mimic the steel from a shipwreck. The limestone plate mimics the carbonate that forms in place in the canyon. Coral tends to grow on all three of these materials.
We removed the plates as aseptically as possible. This meant that I would wear gloves, grab the plate with a bag, which was previously labeled (Stack 1, top or Stack 4, bottom, etc.), remove the plate from the nylon threaded rod, and let it slide all the way into the bag. Once we collected all of the plates, we went into the wet lab and preserved them using RNALater. The plates were put into the refrigerator and will stay there one day and then be moved into the freezer. Once Mike gets back to his lab, he will microscopically look for settlement of coral spat, hydroids, etc. and can also sequence the material.
We assume that colonization occurs in the following manner: bacteria, then coral, then other invertebrates, etc. This experiment will help to demonstrate the colonization process on different materials within the deep water canyons. It’s incredible just how much information can be gathered from these landers and the experiments that they contain.