Montana State team conducts deep-sea research more than 10,000 feet below ocean surface

BOZEMAN - Many Montana State University students arrive in Bozeman - at its roughly 5,000 feet above sea level - and only climb from there, ascending southwest Montana's many peaks. But a team from MSU's College of Letters and Science descended nearly 17,000 feet below MSU's elevation, traveling to some of the deepest areas of the sea on a recent research cruise.

Postdoctoral researcher Andrew Montgomery and doctoral student Sylvia Nupp are part of associate professor Roland Hatzenpichler's multidisciplinary lab in the Department of Chemistry and Biochemistry. This spring, Montgomery and Nupp traveled to the Guaymas Basin off the west coast of Mexico for a monthlong research cruise that made Nupp the first student from Montana to descend to the deep sea, according to Hatzenpichler.

It was a trip that Nupp had been preparing for since she arrived at MSU in 2021, after completing her undergraduate studies at the University of Arkansas.

"This happened to be the project that he had funding for at the time, so he asked if I would be interested in deep-sea research, and I said absolutely," she recalled.

Hatzenpichler's lab conducts a breadth of microbial research, from work exploring the human gut microbiome to examining the microbes that live in extreme environments, such as Yellowstone National Park's thermal features. Nupp and Montgomery's work on the ocean floor fell into the latter category, and the Guaymas Basin is an ideal location for such work.

"Scientists have been studying the Guaymas Basin for about 40 years," said Montgomery, who is nearing the end of a three-year postdoctoral appointment at MSU supported by an award from the National Science Foundation for early-career scientists. "The reason that it's interesting is that the tectonic plates meet there, and the way they move creates hydrothermal activity in the subsurface, similar to what happens in Yellowstone. The sediments are very organic-rich, and the combination of those two things means that the microbiology is very, very interesting."

The pair spent nearly all of April aboard a research vessel with about 60 other people. The scientist cohort - which also included researchers from Georgia, Massachusetts, Texas, Wisconsin and Mexico - worked long days to collect and process samples from the ocean floor, maximizing their short time on the ship.

Nupp and Montgomery were interested in collecting sediment from the ocean floor and analyzing it for the presence of carbon-cycling microbes. Such organisms that live near the extremely hot vents are known as thermophiles, named for their high tolerance for heat.

"Microbes inhabit every inch of this earth and places we can't even imagine, with different temperatures, pressures and pHs," said Montgomery. "In this lab, we're studying microbes that live at what we consider the limits of life."

During the trip, Montgomery conducted two deep-sea dives and Nupp experienced her first. They descended in a submarine called the DSV Alvin, a type of submersible vehicle used specifically for research, which is equipped with robotic arms operated by a pilot to collect samples from the ocean floor.

The team visited two primary sites located at roughly 6,000 and 12,000 feet below the ocean's surface. It took nearly two hours to reach the deeper site once Alvin departed the ship. Despite extensive training, Nupp said nothing prepared her for the rush of diving in the submarine.

"When they actually closed the hatch and it was time to go, I was so excited. We splashed down into the water and it was just instantly beautiful," she said. "You could see bioluminescence through the window, which was amazing, and the sea floor itself was kind of incredible. It looked vaguely familiar, because there are crabs and shrimp and things that you're used to seeing, but it was all kind of weird and suspended."

Each dive took roughly eight hours, with two scientists accompanying a pilot on each trip. At the sites, each researcher sought different samples. The trips included geochemists, microbiologists and geneticists conducting widely disparate research all at the same location. Nupp scanned the ocean floor for Beggiatoa, colorful microorganisms that grow in filamentous mats of vibrant colors. Their presence, she said, is an indicator of thermal activity and the carbon-cycling microbes they were looking for. The robotic arms of the submarine scooped up mud and sediment from the ocean floor and packaged it in plastic tubing.

After the long dive day, the scientists immediately shifted into processing samples as quickly as they could. While they can withstand extreme temperatures, the microbes in the samples are sensitive to environmental changes, so the sediment had to be processed in a temperature-controlled room that Nupp likened to a giant refrigerator. Working through the night, the scientists recorded thorough notes describing the exact attributes of each sediment sample before slicing them into inch-thick "horizons," which help to examine the variety of life present at different sediment depths. They repeated the process through every sample: roughly 80 bottles, Nupp said.

While the work was taxing and time-sensitive, Montgomery said the pressure created a unique sense of camaraderie within the team, even though they all came from different institutions.

"It's almost like if you were going to a summer camp," he said. "You're constrained to the same group of people for an extended period of time, and that builds some community that otherwise takes a while to come together naturally."

Nupp and Montgomery have returned to MSU with samples to study over the coming months. Many microbes collected in extreme environments are notoriously difficult to cultivate for study in a laboratory. Nupp's continued work will seek to isolate, identify and study the organisms that are contributing to carbon cycling near the sea floor's thermal vents in Guaymas Basin. Nupp said Hatzenpichler has pioneered new methods of incubating such microbes, so she said she is in an ideal environment to further her study.

She also plans to continue collaborating with the scientists she met on the ship. As individual teams pursue their own veins of study, their discoveries will provide fodder for new inquiries across the group.

"This is exploratory work. We're trying to look at what organisms are doing, because we don't have an understanding of that yet," Nupp said. "The next step is setting up incubations with different carbon compounds to see what would produce methane and show activity of methanogens. I'd never been on a research cruise before, so there was a lot of learning from everyone and figuring out where my work fit into that. It was a very, very collaborative environment, which made it so much fun."

Nupp, Montgomery and Hatzenpichler also brought their fascination to two local elementary schools, where they discussed work on a research ship. Students painted Styrofoam cups, which were then attached to the outside of submersible Alvin, and taken to the deep sea. Compressed by the incredibly high pressure, the cups shrank dramatically. After they came back to Bozeman, Nupp and Montgomery gave students their compressed cups and chatted with them about their experiences in the deep sea.

More information about research in the Hatzenpichler lab can be found at www.environmental-microbiology.com.