My name is Jesse McNichol and I’m a graduate student in the MIT/Woods Hole Joint Program and along with my supervisor, Dr. Stefan Sievert, I study the microbiology of deep-sea hydrothermal vents. These ecosystems are extremely unusual on Earth, since they are mostly supported by volcanic activity instead of the sun’s light. The oxidation of hydrogen sulfide and hydrogen gas are probably the ultimate source of food for all the teeming life around these hot springs, including the large fishes, tube worms and crabs.
I’d seen these ethereal ecosystems before through a video monitor, and I was fortunate enough to see them up close and personal in during our research expedition in November 2014 from the window of the submarine Alvin! Seeing the huge black smoker chimneys and the giant tube worms reminded me why I became so fascinated with vents in the first place. Because they are so different and mostly independent of sunlight, many people (myself included) study them to better understand how life might exist on other planets, such as in the oceans of extraterrestrial moons Europa or Enceladus.
Although a fascination with life on other planets is what brought me into this field, the motivations for this study are more ‘down to earth’. While the genomic revolution has given us an incredible amount of detail on which organisms exist in deep-sea vents, we actually know very little information about them. How fast do they grow? How much energy they need to survive? How do they interact with one another? In short, we have a very incomplete picture of the ecology of these unique deep-sea environments.
Being at the bottom of the ocean, under over 250 atmospheres of pressure, these ecosystems are naturally very difficult to sample. That’s why I’m fortunate to work at Woods Hole – not only do we have access to the R/V Atlantis and the submarine Alvin, my supervisor’s long-time collaborator Dr. Jeff Seewald has designed and pioneered a sampling device that can bring to the surface an accurate ‘snapshot’ of the deep-sea community, and keep the microbes under the intense pressure found in the deep sea. Although it had been used routinely before for chemical sampling, I was the lucky graduate student to get to try growing microbes for the first time in Dr. Seewald’s samplers.
Given this incredible opportunity, I spent a lot of time thinking about what conditions to test to unlock the unsolved mysteries of these ecosystems. Eventually, I carried out 53 high-pressure incubations during two oceanographic cruises in 2014, which continue to yield new insights as I process the chemical and genetic data. In the end, this work will yield clear estimates on the productivity of the microbial community at deep-sea hydrothermal vents, which will help us understand the ecology of the whole system.
For the general public, the scientific details will not be as important, but I hope that when people see how much more we have to learn about these ecosystems on Earth, it will inspire them to learn more about what I think is the greatest story yet to be uncovered – how life arose and evolved on Earth and how it could exist outside of our small planet.
To support the telling of these stories, MO BIO plays a key role. Although I often still use ‘old school’ DNA extraction techniques, DNA and RNA extraction kits are essential for our everyday work in the lab. We use them to generate high-quality DNA and RNA for experiments that help us to understand these organisms and their ecology better, especially the effect of different chemical conditions on the activity and expression of poorly understood metabolic genes.