UCalgary researcher joins Canadian team exploring the deep sea

A marine hydrogeologist from the University of Calgary’s Faculty of Science has joined an expedition exploring the deep ocean off the west coast of British Columbia.

Dr. Rachel Lauer, PhD, associate professor in Earth, Energy and Environment, travelled to Haida Gwaii by plane, taxi, ferry and inflatable boat to get to the Coast Guard vessel J.P. Tully on Aug. 22 for the second half of the NorthEast Pacific Deep-Sea Exploration Project (NEPDEP).

It’s not Lauer’s first time on such an expedition. She was also part of a team of international scientists who discovered a new deep-sea octopus nursery at a low-temperature hydrothermal vent offshore of Costa Rica in June 2023.

The Canadian expedition, which runs from Aug. 13 until Sept. 2, is exploring and monitoring deep-sea ecosystems in and around existing, planned, and potential marine protected areas in the Pacific Ocean.

It includes a team of scientists, communicators, and marine planning professionals from Fisheries and Oceans Canada, the Council of the Haida Nation, Nuu-Chah-Nulth Tribal Council, universities, and non-profit institutions. They are using a remotely operated vehicle, ROPOS, to conduct science and capture images of the deep sea.

We sat down with Lauer before she left on her trip to learn more about her role on the expedition.

Q: Tell us about your research.
A: The second half of the cruise will spend some time focused on seamounts in this region. We believe there’s a hydraulic connection between them and hope to measure that connection using multiple marine heat-flow probes that I have borrowed from marine institutes in the United States and brought along on the trip.

I use geothermics, or heat-flow measurements, to investigate the hydrogeology, or the plumbing, of the ocean crust and how that’s connecting these structures at the seafloor that are basically extinct volcanoes. They are not actively erupting, but they are formed through magmatic processes, and in some cases, they are still very warm. That can facilitate this process of hydrothermal circulation that connects two or more seamounts to each other under the sediments. 

This process initiates when cold dense bottom water goes into one location, getting warmed up through the Earth’s heat, changing chemically — potentially taking on and translating microbes as well — to where they are delivered at the seafloor at a discharge site. Those, both anecdotally and through many recent expeditions, seem to be places with a lot of biodiversity.

One of the places they were diving on Wednesday and we’re returning to when I am there is the location where they found more than a million deep-sea skate eggs, an octopus nursery, just incredible amounts of life — despite being very similar to a nearby volcano in the same cluster that looks like a desert, except for carnivorous sponges on the surface. 

The hypothesis is that’s where the water is going in but, after that water has been translated and warms up, it takes on a different chemistry and perhaps microbes that are fuelling this biodiversity. It’s a thousand metres of life on the seafloor. For whatever reason, the critters like to be in that water — whether it’s the temperature, the chemistry, the microbiology, that hasn’t been established yet. We do know, at least in Costa Rica and on Davidson Seamount off California, which are the two other locations where there are octopus nurseries, the warm water seems to shorten their gestation period for their eggs, so they are actually speeding up this incubation process.

Q: How will you measure heat flow?
A: I’m bringing these heat-flow probes that look like lances. The 60-centimetre-long titanium probes will be mounted on the ROPOS, which has two articulating arms to insert into the sediment on the seafloor. It takes about 15 minutes to do one measurement. Through the computer, I am tethered to the instrument. It’s live. 

The pilots are controlling ROPOS’s positions, the thrusters, buoyancy, all of that, while also controlling these arms. It's basically the most expensive video game in the world that these guys are playing. You’re sitting next to them saying, ‘I want that, can you try putting it in over there or can you grab that sponge?’

I am one of the only people on the ship who’s not a biologist. We also have Haida and Nuu-Chah-Nulth partners on the ship who are co-ordinating with a lot of the work that’s been done previously in the establishment of a massive marine protected area nearby.

Q: Why is this important?
A: Now that we are thinking about deep-sea mining, there’s a push to protect the seamounts that have a lot of biodiversity. But if that seamount is connected to the deserted one, where water is going in, we need to protect them both.

That’s primarily why the Fisheries and Oceans Canada scientists are interested in working with me. We need to think about how they are all connected and the patterns that are established because of those connections. My entire postdoc was spent simulating this process in three dimensions with many different combinations. Now I get to test it.

Q: How are you feeling about the trip?
A: I am terrified, as I should be. Every time there’s high-risk, high-reward science, it’s always, ‘I really hope this works.’

At the same time — instead of spending all that time running 72 simulations on five different Linux machines for two-and-a-half years to get one paper and having to develop an intuition about this process and how it works and the physics of it — I get to actually observe it at the seafloor. That’s what was so cool about (the trip to Costa Rica) last year. There were things we observed in the physics that we had never observed in nature — and we got to see that.

The expedition is being livestreamed here.