Maybe you are asking how we all got here, 2.5 km below the ocean surface. If not, it is certainly one of the first questions that pops to my mind when I look around the lunch tables and the lab benches on the Atlantis. I asked around, and got one of two answers; either they arrived driven by passion for the deep sea, its microbes and animals, or they had perfect timing, they were at the right place at the right time. For me, this has been a journey of passion for the eccentric microbial world.
Since I learned about hydrothermal vents and the fascinating microbes (chemoautotrophs) that maintain these primitive environments I was hooked. I knew I would one day study how they grow, where they grow, and who they are. Nonetheless, seeing the videos of deep sea vents and pictures of the Riftia worms seemed light years away siting in my parents apartment in the middle of the Andes mountains 2.6 km above sea level. However, I was determined to try. I started building up a career as a marine microbiologist jumped back and forth over the Atlantic, to study chemosynthetic metabolisms like sulfur oxidation and nitrification in marine environments. Today, less than a year after finishing my PhD, I find myself on the Atlantis research vessel a few days after meeting the great hydrothermal vents of 9°N face-to-face on the 4900th Alvin dive.
The Alvin dive starts with a soothing 2 hour descent, enough time to settle into your new reality: ‘there is a 2+ km thick column of water above your head! there is no quick way out anymore’. I am a scuba diver and practiced some free diving in the past, so I know what it feels like to immerse yourself and stay underwater. The idea of the wall of water above my head is thus simultaneously terrifying (because it can crush you) and exhilarating (because who knows what you might see this time out). Once underwater I always focus on the little organisms in the water column to forget the terrifying part and enjoy the dive. The same occurred during my Alvin dive. Going down I was feeling uneasy so I stared out my window and was delighted by the silent dance of the many bio-luminescent lifeforms streaming by.
When we finally approached the bottom, Alvin’s lights were on and I found myself peaking into the dark ocean, hovering above a majestic submarine lava field, filled with anticipation of what was to come (not caring anymore about the cubic meters of water above). During our 4 hour dive we visited several sites: Crab spa, Bio 9, P vent, Teddy Bear, and M vent which gave me a birds (or rather fish) eye view of the diverse landscape you can find at 9°N.
We saw meter high chimneys with warm (and thus denser) fluids pouring out, black smokers that cast a “shadow” over the Alvin, juvenile fish bathing in the vent fluids, and white snowy flocks shooting into the black ocean. I also saw a variety of rock formations: black, orange, white, furry (covered with microbial growth), shinny, opac, sharp, and round silently waiting for the next eruption. We glided over a field of collapsed gas domes as big as the Alvin and sailed through the central axis that serves as a highway between the different vent outflows. Immersed in this incredible environment we set out to collect samples for the entire science team. First we positioned the nossel of the large volume pump into the vent fluids at Crab spa to collect samples for chemical and microbial analysis. Secondly we re-deployed a microbial colonizer on Alvinella mound (alias “wedding cake”) that had fallen down.
Afterwards we moved to Bio 9 to set a crab trap filled with Riftia and mussel bate, and then settled next to a field of Riftia to enjoy our lunch. This was probably the most memorable part of my trip, since we were able to just sit and observe, take a couple of minutes to pretend we belong. During this pause I saw orange shrimps and white lobsters rowing in front of the Alvin, numerous crabs marching towards the crab bate, little tube worms waving in the water, nervous meter long red Riftia (worms) popping in and out of their tubes, and oblivious white fish hanging out in the Riftia colonies (just to mention a few).
After lunch Phil and Stefan took me for a tour of Bio 9, a black smoker that spews out hot black vent fluids, what a sight! I had seen similar images in almost every article I read about deep sea vents, and now I was here taking the pictures, just priceless. Then we flew over to Teddy bear to take vent fluid samples for incubations on board and collected a crowded crab trap that had been placed in a previous dive. Finally we collected three hand fulls of Riftia in the biobox attached to the front of the Alvin and strolled along to M vent to see the impressive structures. By then it was 15:15, it was time to go back to the surface, what a sad thought. I would prefer to stay and have dinner with the Riftia colonies.
Back on board the Atlantis, I stared out over the vivid blue ocean and think of the magical world that lies (way) below. What an adventure this was! I will definitely return to continue studying my chemoautotrophs. Thanks to all the Alvin and Atlantis crew for making this odyssey possible and special thanks to Stefan Sievert for inviting me along and making my wildest dream come true.