I am a master’s student from Germany and have been working on my thesis in the laboratory of Stefan Sievert since the beginning of April 2014. Together with Jesse McNichol, I worked on a model microorganism called Sulfurimonas denitrificans to aid in the understanding of a bacterial group that appears in high numbers in hydrothermal vent fluids.
If anyone had told me at the beginning of April that I would go diving with the Alvin submarine to an unknown place at the bottom of the ocean at 2700 meters, I would have never believed it. But on Wednesday, November 20, 2014, I did it. Together with Scott White, a professor from the University of South Carolina, and Bruce Strickrott, an experienced Alvin pilot, I went down to the bottom of the ocean with the aim of finding new hydrothermal vent sites off-axis to the East Pacific Rise.
I have done a lot of recreational diving, and the first thing I noticed when the Alvin dive started was that the light reached down to a depth of almost 200 meters. There were stripes of weak green; it was not fully dark. But afterwards our surroundings turned deep black. We shut down the lights to save energy during the descent, and when you looked out one of the five windows you could see little organisms passing by creating a green light through the process of bioluminescence. For me it looked like flying through the galaxy.
After more than an hour, we came close to the bottom and turned on the lights. I could not believe my eyes when the bottom appeared out of the deep blue and came closer and closer. We landed on a flat sediment area and it was amazing to see so much life in this habitat in the first glimpse I had. Big fish were hovering head down in the dark. They had a big white head and a thin long tail. Others looked like white eels. The whole surface of the seafloor seemed to move: sea stars of all kinds, shrimps, and crabs were moving in every direction trying to hide from the light. For them it probably was the first light they have ever seen.
We started towards an area 1 to 2 kilometers above a magma chamber to look for hydrothermal vent activity. For the first few minutes we were flying over the sediment bottom and took also a sediment core sample. After a short time, the first structures appeared out of the sediment. Rocks covered in sediment became numerous. Some of these rocks were home to deep purple anemones, white sponges, white corals, and sea cucumbers in many different forms and colors.
We flew over a more rocky area. Suddenly a big white shadow appeared to the left of the submarine that nobody else could see. When it came closer to the sub the shape looked like a white turtle swimming slowly away. I said to the pilot: “There is a white turtle swimming away on the left side of the sub.” We turned and drove closer to it. The “white turtle” was a huge dumbo octopus. On its body two white wings (shaped like shark fins) enabled the octopus to swim calmly through the water. An hour later as we were sampling a rock and two sediment cores, another white shadow was laying in the sand in front of us. We sneaked towards it and saw a big white sting ray lying in the sand. When we came too close, it swam towards the sub and passed underneath.
We continued to sample rocks and sediment cores along the dive route. We flew back towards the East Pacific Rise axis. We flew over old pillow lava, sheet lava, and lava channels. These formations looked a bit like the fingers of a giant coming out of the sand. We approached the edges and dove down steps several meters tall. Finally we moved upslope toward the East Pacific Rise axis where we also took some samples until we had to finish the dive.
We did not find new hydrothermal vents or diffuse flows, although we explored many rocks and many cracks in the seafloor. We brought up nice rock samples, whose age still has to be determined, and sediment cores that will be investigated for microbial diversity. We drove a distance of more than 3 kilometers at depths from more than 2700 meters up to 2500 meters. When we ascended, the bioluminescence looked like green rain pouring onto the sub.
It was an adventure I will never forget in my entire life. I want to thank Stefan Sievert, Scott White, and Bruce Strickrott for giving me this once-in-a-lifetime experience!
Editor’s note: Among his lab-mates in Woods Hole, Florian is famous for his spirited karaoke performances. When he returned from his dive, he was handed his favorite neon green safety goggles and a prop mike. With fabulous backup from Fengping Wang and Camila Negrão Signori, he treated us to a modified rendition of his favorite song, Red Hot Chili Peppers’ “Under the Bridge,” before being doused with iced seawater for his Alvin initiation.