The last time we spoke to Shannon Johnson, Deep-Sea Research Technician with the Monterey Bay Aquarium Research Institute (MBARI), she explained that her job as “like watching the Discovery Channel in real-time.” Shannon applies her background in ecology and zoology to solve the mysteries that surround creatures of the deep sea. We recently caught word that Shannon spent an exciting summer collecting deep-sea samples in the South Pacific, so we sat down with Shannon to find out what her tropical endeavors entailed.
Since it has been over a year since we last spoke, why don’t you update us on how you’ve been staying busy as a deep-sea researcher.
SJ: Well, I’ve been working on a number of things. Right now I am working on publishing a paper that describes five new species of deep-sea snails using only their DNA. It’s not totally ground-breaking science, but it’s definitely a new technique. In the past, people have often described animals using their traits—some birds are described using their song, for example—but we are now using DNA for identification.
Can you talk a little bit about what that process looks like?
Since all of the animals I work with are deep-sea animals, collecting them and sequencing their DNA can be a pretty involved process. It isn’t the easiest thing to collect animals from the deep-sea, as many times they are located miles off shore and in specific areas like hydrothermal vents or whalefalls. Another challenging thing about working in the deep-sea is that there is a ton of crypticism, which means that many animals look the same even though they are, in fact, different species with distinct evolutionary lineages.
Since we are working with a number of different types of animals, there isn’t just one way we go about identifying them. Once we have the DNA extracted, there is a number of genes that we can use to tell them apart. My boss has an awesome analogy to describe genetics: all of the different genes we use is like a set of golf clubs. In golf, sometimes you need a putter to make the shot, and sometimes you need a driver. Similarly, we use a number of different genes to identify different species based on the circumstances.
The hard part about DNA sequencing is knowing that the genes mean once it is sequenced. People say that sequencing DNA is hard, but it’s really not difficult. The difficult part comes in knowing what the DNA means once it is sequenced.
So how do you go about matching the DNA to different species once it is sequenced?
Once we get the DNA information for a species, we run it through a database to see if it matches anything. This process is very similar to what happens when someone’s fingerprint is collected and run through a database to find a match. Identifying these deep-sea snails that we have been working with can be particularly difficult because they are so different: they do different things and live in different types of environments. That’s one thing that makes this paper I’ve been working on so important. We need conventional ways of identifying these species.
So if someone were to ask you why the study of deep-sea creatures like these snails is important, what would you say?
That’s an interesting question. I personally like studying these things because I find them really interesting and really cool. But one of the most interesting things about these snails is the unique way that they speciated. Typically animals will speciate—or evolve from being one species to being different species—because of some some long-term major separation that causes a disruption in gene flow. These separations are often caused by physical things like the presence of a mountain range or a large current. These snail species are different because there are three species that actually live together, and yet they are the most distinct species in the genus. That’s a really rare event, especially in the deep-sea, and it presents a really cool opportunity to test evolutionary hypotheses. So in terms of science, these snails are really interesting.
It’s true that these snails will probably never be seen by people except through the photos we take with our underwater remotely operated vehicles (ROVs). I’m trying to grow awareness of what I’m calling the “punk rock” snails—they live in hot acid, they’re covered in spikes and they have purple blood. They’re a pretty charismatic group, they look cool, and I’m naming one of them after the drummer from The Clash. These snails are also interesting in terms of climate change research because they live in hot acid. Oceans are becoming more acidic with the increase of carbon dioxide in the ocean, so in a climate change perspective, these guys might actually be ok.
Something that you said reminds me of something one of our Cool Jobs meteorologists expressed when he stated that scientists are the modern-day explorers. It seems that your field is very similar to that.
Absolutely. I was not at all interested in marine science as a young person because I thought that scientists had the oceans all figured out. But now I get to discover new species all the time. We literally discover new species every time we go to sea, and we’re not always going to exotic locations. Even when we go out in the Monterey Bay we find not only new species, but new genera and new families even.
Shannon will be traveling the oceans again at the end of this month, so be sure to check back to read all about her experiences at sea.