A few days ago, one of my dreams came true. Ever since I started studying microbes living in deep-sea hydrothermal environments, I have wished I could dive to the deep sea and see the vent communities with my own eyes. This desire became my motivation to push forward with my Ph.D. study. Before this cruise, I had opportunities to join the Japanese scientific cruises and see the deep-sea vents through video. But I have never had a dive in Shinkai 6500 (the Japanese sub), because students are not allowed to dive (in contrast to Alvin, there are two pilots and only one scientific observer in Shinkai 6500). So I was excited and could not sleep well the day before my Alvin dive.
After Alvin started descending, the motions I had felt at the surface stopped. It was completely dark when we passed a depth of around 300 meters. No motions, no lights, no sounds… we would not know where we were without the GPS, depth gauges, and some electronic devices. Also beautiful bioluminescent organisms reminded me that we were going down, because they appeared to be going up slowly.
The first view after we arrived at the bottom was the shiny black basalt. I saw delicate submarine formations; some parts were crumbled, and others were wall-like structures. We looked for the Vent-SID, which had been sent down earlier, and moved it to a site near thriving Riftia (giant tube worm) colonies. I could not believe their lives are completely supported by the activities of tiny microbes.
The pilot, Bob Waters, took us to a vent called P-vent and showed me more black smokers. I had tears in my eyes (though I was looking out through the small window, so I hope nobody saw…). The height of the chimney was over 10 meters. I have no idea how long it takes to grow such a huge structure, but I felt the beating of the earth with the continuous emitting of vent fluids, and that was the thing I really wanted to observe with my own eyes. We finished collecting high-temperature fluids and chimneys at P-vent, then headed to the Crab Spa, and successfully collected a couple of IGTs (vent fluid samples) and rock samples.
The hydrothermal activity was never boring to watch. I wished I could have stayed there longer, but we had to leave the bottom of the ocean and go back to the real world. The dive was like a dream (of course there were tube worms in my dreams after the dive!). But I am sure we saw the energy-filled dark life, which we cannot feel from watching videos.
I would like to express great thanks to chief scientist Stefan Sievert, who provided me with this wonderful experience. Also I appreciate the Atlantis and Alvin crews for supporting safe cruises and dives, and the scientists for sharing the good times and preparing a great initiation for me. I’ve promised myself that I will work hard to hopefully get another opportunity to dive to the seafloor again someday.