September 6th, 2023 | By Oriana Smy
People of the Ocean Decade: Dr. Cherisse Du Preez
Behind every UN Ocean Decade Action is a team of dedicated and passionate ocean professionals. Oriana Smy had the opportunity to sit down with Dr. Cherisse Du Preez, who is certainly no exception to this statement. Dr. Du Preez is the Head of the Deep-Sea Ecology Program at the Department of Fisheries and Oceans Canada (DFO) and an Adjunct Professor at the University of Victoria. Or as she sees it: “I get paid to explore the deep-sea, which is a really cool job!” As Canada has committed to protect 30% of the ocean, she feels honoured to look for the amazing places and animals within deep-sea ecosystems to help reach that level of protection.
Most recently, Cherisse held the role of Lead Scientist for the two-week long 2023 NEPDEP expedition – or as she likes to pronounce it, NEEP-DEEP. “This way it sort of sounds like a cute little robot,” she tells me as she animates with exuberance over the expedition’s beloved underwater vehicle, ROPOS, from the Canadian Scientific Submersible Facility, which has the capability to dive to depths greater than 3,200 meters. “This is where I find joy in these silly little acronyms,” she adds. NEPDEP stands for the Northeast Pacific Deep-sea Exploration Project.
The NEPDEP expedition is an endorsed UN Ocean Decade Action and Challenger 150 Activity. It is a collaborative voyage co-created by Fisheries and Oceans Canada, the Council of the Haida Nation, Nuu-chah-nulth Tribal Council, Pacheedaht and Quatsino First Nations, and Ocean Networks Canada. These relationships have been formed over many years of co-produced knowledge through co-developed deep-sea expeditions.
The list of objectives for this expedition was long and ambitious, but the overall aim for the team of 17 scientists was to explore, monitor, and to better understand the deep-sea ecosystem of this region, inclusive of the proposed Tang.ɢ̲wan · ḥačxʷiqak · Tsig̱is Marine Protected Area (Pacific Offshore Area of Interest).
These collaborative deep-sea expeditions have been going out since 2017, with a year off during COVID. “This was definitely the best one yet,” Cherisse informs me with a beaming smile, representative of her absolute stoke on the voyage. Prior to embarking on this particular expedition, the group collectively had a diverse range of expert knowledge to know that they would check at least a few of those boxes. “You can have all of the know-how and hope that you can find something all you want, but it’s the largest ecosystem in the world, and you just might not find it.”
Even with the shared expert knowledge onboard and in the planning stages of this expedition, and all the hope in the world, she tells me, “never in our wildest dreams could we anticipate what we discovered. It was absolute crazy town! It was literally every dive that we found something new and exciting.” Even with all of the expert knowledge, “isn’t it a wonderful thing that the deep-sea still surprises us?”
An integral part of these expeditions is the onboard communications technology, with each of the dives live-streamed to an international audience. The whole world was watching and sometimes they would have tens of thousands of viewers logged in at one time. One of the many notable claims from this voyage came from the last dive of the expedition.
“Once we started seeing the number of people logging in, we knew it was really big.” The NEPDEP team became the third science group in the world to discover a deep-sea octopus nursery garden, which they found at cold seeps on the ocean floor. Cold seeps are areas of the sea floor where methane is released and makes chemosynthetic energy in the absence of sunlight, creating habitat for endemic animals that live nowhere else.
“The cold seeps we found were amazing – these alone should have stolen the show. But of course, these cute squishy little purple octopuses were there, with big black shiny eyes, ever so cute, guarding their eggs, and actually punching crabs who were coming in and trying to get the eggs.” These particular octopuses sit on the seafloor and incubate their eggs for [at least] four-and-a-half years, holding the record for the world’s longest incubation period of any animal. Which is why Cherisse calls them, “the super moms of our planet.”
Originally from South Africa, Cherisse was always immersed in the marine environment. From an early age she was a competitive surfer and diver, specializing in shark and whale diving, which sparked her interests in becoming a marine biologist. “I thought pro surfing was going to be it for me,” she says. After the first year of university, to her dismay, she found it immensely difficult and flunked out. Coming to terms that academia just wasn’t the path for her, she went on to become a dive instructor and followed her underwater passions through other streams in photography, videography, and storytelling.
In a serendipitous moment, Cherisse sat next to her former English professor on a bus one day and explained her accepted fate of a non-academic life. “Well, you know there’s help for dyslexia. If you ever want to go back, I could give you some resources,” they told her.
“Wait, what?” she responded in utter shock, not understanding at the time exactly what dyslexia was, or that it was something that had been plaguing her studies. “I went and got tested and the diagnosis changed my life. I got a computer that had a specialized reading and writing program.” She then dove back into academia head first with a whole new approach. Now equipped with the right tools, she went on to getting straight A’s and followed her dream of becoming a marine biologist after all.
Although it may have been a round-about way of getting there, Cherisse felt much more equipped to go into the field with new hobbies and a diverse range of experiences and skill sets. “I think that’s why I get to do the job that I do, because I have all of these quirky other things that I bring to the table.”
Fast forward a few years, Cherisse couldn’t imagine that her line of work would eventually bring her to the “hot spot” of deep-sea exploration. “I’m not even biased,” she tells me. “I could write peer reviewed papers that prove that the Northeast Pacific is objectively the best place on earth to study the deep ocean,” an area rife with seamounts, cold seeps, and underwater thermal vents. “I can’t even believe I can just depart a dock on a boat and within a day and I’m in the best place on the planet to do this work.”
The naming schema of the NEPDEP dive sites are passed on to the coastal First Nations involved. In the meantime, these sites are given an alphanumeric name. The interim NEPDEP 58 site is known to be at a triple junction of the tectonic plates, where the Pacific, Juan de Fuca, and North America plates join.
“We knew this site held the newest seamount of the underwater mountain range, but we didn’t know that it was active,” Cherisse tells me as she explains that this is the first-time in Canada that we have hydrothermal venting fluid actually coming out of a seamount. “We care about hydrothermal vents, they’re something we try to protect. We care about seamounts, and now you have a special thing on top of a special thing – so it was amazing!”
But wait, there’s more! As if this revelation wasn’t enough, the NEPDEP discovered skate eggs in the hot water, which has only been documented once before in the Galapagos Islands, where scientists found a small pocket of around 100 eggs. “They hypothesize that deep sea animals lay their eggs in hot water to make for stronger young and it speeds up the incubation period - which for deep-sea skates is also four years,” Cherisse informs me. “The deep sea is amazing for that. It does everything bigger, and slower, and longer.”
What’s even more incredible about this site, is the sheer number of eggs, which are quite large at approximately a foot and a half long each. Conservatively, Cherisse tells me they estimate there were over a million. “More likely five million large deep-sea skate eggs.”
What they discovered was that the adults are flying up from the deeper abyss and leaving their eggs in the shallower waters at the top of this active underwater volcano, and presumably returning to the depths of 3000 m or more where they are found as far away as Australia, China, and other far away parts of the Pacific Ocean while their young incubate in the warm waters at the hydrothermal vents.
As the expedition was also filming for a new BBC series, there was a request to keep an eye out for the rare chance of seeing a skate actually laying an egg. Cherisse informs me the likelihood of this is pretty slim. “Then sure enough, we’re on a dive and a female flies over and she’s laying an egg!” So the team followed her with the ROPOS for an hour to document this amazing behaviour. “We captured essentially the dance that these females do to lay the eggs and we watched her put them on this active volcano.” This had never been filmed before. Now they had new discoveries, upon new discoveries, upon new discoveries.
Just as they think they’ve hit the maximum overload of discoveries, they reach the pinnacle of the seamount and find the remains of a whale that had died and sunk to the bottom of the sea (a whale fall), which just so happened to land right on the summit of this underwater volcano. She puts the rarity of all of these encounters into perspective by explaining that some people in all of their careers might see one of those things, maybe if they’re very lucky, and all of these discoveries happened in one single dive. “That’s when you question, do I throw in the towel? Should I now retire? It’s never going to get better than that.”
The NEPDEP expedition partners included four First Nation communities and 35 other organizations and institutions, inclusive of Knowledge Holders, biologists, mappers, oceanographers, graduate students, and storytellers. Once the expedition returns to shore, they take the core samples and the footage and all of the data collected and they get them in as many hands as possible. “We give it away as fast as we can, so that they can begin analyzing the mass amounts of data, because a lifetime at my desk, with just one or two people, couldn’t process it all.”
Although Dr. Du Preez is one of the top expert deep-sea scientists in Canada that many look to for guidance and advice on this unique ecosystem, she notes: “I don’t know everything. I’m not a taxonomist, or a geologist.” She notes, to highlight the wide range of disciplines interested in getting their hands on these data.
In addition to all of the epic, attention-grabbing, show-stopping discoveries, the NEPDEP expedition collected over 300 specimens for sampling. Already, only one month after returning from the expedition, taxonomists had sampled three of those specimens and discovered all were entirely new species to science. “So it’s three for three so far and we still have a lot to sample,” Cherisse tells me with the excitement of a kid on Christmas morning just waiting to unwrap the mysteries of deep-sea delight.
When I asked how they kept morale up onboard, she told me that “it was the happiest expedition ever!” She attributes that by giving everyone ownership over the project, it collectively made this all possible - oh, and the quick mid-day single song dance parties. “It’s really funny because you’ll see the most serious scientist walking down the hall and as they get to the lab, they see the strobe light, and no questions asked, you just start dancing. And then when the music stops, you go back to your computer and you start working again.” They also had a big “HYPE” button that they hit when something really amazing happens – “whoop whoop whoop” – to which she says they lost count of how many times it went off. “Daily that’s for sure.”
“Collectively we all held this sense of responsibility and pride to deliver something to the Canadian public, and to the global public.” Cherisse states, it wasn’t just her filming and directing for BBC, everybody was responsible for calling out the shots and documenting. “I think a lot of the fun comes across when we’re narrating the live streams. Not only are people watching the footage of us exploring the deep sea, but they can literally hear everything we’re saying. For better or for worse, they seem to enjoy it!”
Cherisse tells me that this is really the perfect time to study the deep sea, because there is both this movement to exploit it, but also we now have the tools and technology to understand and protect it in a way that’s never been done before. The deep sea is part of a global conversation right now that hasn’t happened before. “It’s a wonderful job to have, when people are dying to know more so that they can make informed decisions.”
A lot of people get to work in the deep sea, but there’s something special in the way that Cherisse approaches her work. “I think it’s because I don’t just come at it from a science point of view, but it’s the storytelling aspect.” She presses the importance of public opinion with everything that they do. “When people know about your work, they want to support you in your work, and then you get to do it more. Even within the realm of deep-sea science, I know that I’m very fortunate in the things that I get to do.”
Although knowing what is in the deep sea can have implications for decisions around exploitation, Cherisse chooses to show up at the table to share the knowledge of the deep ocean. “They’re going to make whatever decisions they’re going to make, but as long as it’s based on informed decision-making, that’s all I can ask for.”
She laments on the earlier plights of deep-sea exploitation in the fishing industry and provided an example of showing underwater videos of the sponge reefs. “Most people didn’t know that they were living animals. They thought maybe plants, or these dead white things.” She notes just how important sharing this knowledge and information is to advance our understanding and encourage protection, and how the public opinion piece is so key.
After the hype from two-weeks of absolutely mind-blowing discoveries, and then returning to the docks to respond to an onslaught of media inquiries and sifting through scientific journals to submit to, Cherisse outlines the next steps. “Now for the fun part, which is just sitting down and writing the papers and disseminating the data.”
Already the NEPDEP team has found a home for some of these papers and co-authored and submitted a paper barely a month after returning to the shore, which is a very unusual and a tight turnaround for the science community. “So many of these things were so ground breaking that they required placement in science as fast as possible, because they have very real implications for decisions like deep-sea mining.”
Cherisse and her colleague Heidi Gartner set off to Brazil in August to speak at a conference and start to get this word out to the world so others can direct their science around these new deep-sea discoveries. And then for years, or maybe for the rest of her career, papers will trickle out from the dives done last month.
“Thank goodness for not knowing I was dyslexic,” she laughs. “I don’t regret failing out of school and having to go at it the hard way and then come at it from a different angle. The NEPDEP really is an expedition that could leave me for the rest of my career trying to catch up. It’s a very happy problem to have.”
Cherisse has such an infectious enthusiasm and love for the deep sea. She encourages young scientists to pursue their passion for the ocean – and to always show up as your unique and authentic self, however quirky that may be.
