Voyage to the Galápagos Explores How Ocean Nutrients Sustain Life

Though microscopic, plankton form the foundation of the marine food web and play a key role in regulating Earth’s climate. Photo courtesy of Karina Vivanco.

Though microscopic, plankton form the foundation of the marine food web and play a key role in regulating Earth’s climate. Photo courtesy of Karina Vivanco.

During the "R/V Marcus Langseth" expedition, scientists collected and examined plankton communities that both power Galápagos ecosystems. Photo courest of Karina Vivanco.

During the "R/V Marcus Langseth" expedition, scientists collected and examined plankton communities that both power Galápagos ecosystems. Photo courest of Karina Vivanco.

Chemistry Professor Claire Till on deck of the “R/V Marcus Langseth” in the Galápagos Marine Reserve. Photos courtesy of Karina Vivanco.

Chemistry Professor Claire Till on deck of the “R/V Marcus Langseth” in the Galápagos Marine Reserve. Photos courtesy of Karina Vivanco.

The Humboldt Chemistry Trace Metal Team used GoFlo bottles, seen here, to collect seawater samples at different depths and at different times of the day. Photo from Claire Till.

The Humboldt Chemistry Trace Metal Team used GoFlo bottles, seen here, to collect seawater samples at different depths and at different times of the day. Photo from Claire Till.

Noah Schuhmann(left) and Ralph Till (right) manage the taglines—which help provide stability for the GloFlo bottles as they are deployed to collect water and take measurements of temperature, salinity, and depth of the water. Photo courtesy of Claire Till.

Noah Schuhmann(left) and Ralph Till (right) manage the taglines—which help provide stability for the GloFlo bottles as they are deployed to collect water and take measurements of temperature, salinity, and depth of the water. Photo courtesy of Claire Till.

Claire and Ralph (left) work with the marine technicians (right) to attach a GoFlo bottle to the line just before deploying it. It will go down into the water open, and they will trigger it to close at the depth they want. Photo from Karina Vivanco.

Claire and Ralph (left) work with the marine technicians (right) to attach a GoFlo bottle to the line just before deploying it. It will go down into the water open, and they will trigger it to close at the depth they want. Photo from Karina Vivanco.

From left to right: Noah Schuhmann, Ralph Till, and Claire Till stand inside the “bubble,” a cleanroom they constructed onboard the research vessel to prevent potential contamination of the seawater samples they collected. Photo from Karina Vivanco.

From left to right: Noah Schuhmann, Ralph Till, and Claire Till stand inside the “bubble,” a cleanroom they constructed onboard the research vessel to prevent potential contamination of the seawater samples they collected. Photo from Karina Vivanco.

The Humboldt Chemistry Trace Metal Team performed an incubation at sea, adding iron and observing the effect on the phytoplankton. Noah Schuhmann (left) and Claire Till (right) take the first sample of their incubation. Photo credit: Ralph Till.

The Humboldt Chemistry Trace Metal Team performed an incubation at sea, adding iron and observing the effect on the phytoplankton. Noah Schuhmann (left) and Claire Till (right) take the first sample of their incubation. Photo credit: Ralph Till.

A close-up view of plankton captured during the Galápagos expedition. Photo courtesy of Karina Vivanco.

A close-up view of plankton captured during the Galápagos expedition. Photo courtesy of Karina Vivanco.

Though microscopic, plankton form the foundation of the marine food web and play a key role in regulating Earth’s climate. Photo courtesy of Karina Vivanco.
During the "R/V Marcus Langseth" expedition, scientists collected and examined plankton communities that both power Galápagos ecosystems. Photo courest of Karina Vivanco.
Chemistry Professor Claire Till on deck of the “R/V Marcus Langseth” in the Galápagos Marine Reserve. Photos courtesy of Karina Vivanco.
The Humboldt Chemistry Trace Metal Team used GoFlo bottles, seen here, to collect seawater samples at different depths and at different times of the day. Photo from Claire Till.
Noah Schuhmann(left) and Ralph Till (right) manage the taglines—which help provide stability for the GloFlo bottles as they are deployed to collect water and take measurements of temperature, salinity, and depth of the water. Photo courtesy of Claire Till.
Claire and Ralph (left) work with the marine technicians (right) to attach a GoFlo bottle to the line just before deploying it. It will go down into the water open, and they will trigger it to close at the depth they want. Photo from Karina Vivanco.
From left to right: Noah Schuhmann, Ralph Till, and Claire Till stand inside the “bubble,” a cleanroom they constructed onboard the research vessel to prevent potential contamination of the seawater samples they collected. Photo from Karina Vivanco.
The Humboldt Chemistry Trace Metal Team performed an incubation at sea, adding iron and observing the effect on the phytoplankton. Noah Schuhmann (left) and Claire Till (right) take the first sample of their incubation. Photo credit: Ralph Till.
A close-up view of plankton captured during the Galápagos expedition. Photo courtesy of Karina Vivanco.
At 4:30 a.m., before the first rays of sun reach the waters surrounding the Galápagos Islands, trillions of phytoplankton drift in the dark, waiting for the light of dawn to trigger photosynthesis—the process that releases oxygen and energy into the ocean and the marine food web.

But before that daily burst of life begins, members of Humboldt’s Trace Metal Team are already at work on the deck of the “R/V Marcus Langseth.” Using a winch, they lower GoFlo bottles—specialized containers to collect water samples without contamination—into the sea. They seal them shut at depths of up to 300 meters to capture water before the light wakes the phytoplankton. By 8 a.m., while most of the ship’s crew heads to breakfast, they’ve already logged hours of sample collection. In the afternoon, they begin the process again, finishing by dinner—a routine they repeated for three weeks. 

Chemistry faculty Claire and Ralph Till, and Microbiology undergraduate student Noah Schuhmann embarked on the three-week research cruise this August to the Galápagos, where they joined an international team dedicated to understanding the region’s oceanography. The data they collect will help scientists better protect marine life in a changing climate.

The project is led by the University of North Carolina at Chapel Hill’s (UNC-CH) Adrian Marchetti and Harvey Seim, who are working closely with the Galápagos Science Center, and researchers at the University of Texas Rio Grande Valley, Monterey Bay Aquarium Research Institute, North Carolina State University, University of Victoria, and Cal Poly Humboldt. 

This summer’s expedition builds on more than a decade of research aimed at understanding how ocean nutrients reach the ocean’s surface and impact phytoplankton communities. 

These microscopic plants are the foundation of the ocean food chain. “They can only grow in the light, so nutrients at the surface of the water are key for their ability to grow,” says Claire Till. 

The Humboldt Chemistry Trace Metal Team—which consists of the Tills and Schuhmann—is zeroing in on one micronutrient: iron.  

“Iron is an essential micronutrient, required in small quantities for plants and animals [to survive],” Claire Till explains. “In roughly one-third of the surface ocean, lack of iron is what stops phytoplankton from growing more.”

Every morning and afternoon, the team—whose participant in the research was made possible with support from the California State University Council on Ocean Affairs, Sciences & Technology—collects seawater samples from different depths to measure the concentration of iron. The findings will help reveal how nutrients travel through the water and ultimately shape the entire marine ecosystem.

Collecting the samples is a delicate task. Because even the ship’s rusty metal surfaces could contaminate them, the team constructed a plastic “bubble” cleanroom. Inside it, they filtered, froze, and preserved samples to further analyze at their lab at Cal Poly Humboldt over the next year. 

For Schuhmann, being aboard the “R/V Marcus Langseth” with students and scientists was transformative. 

“The difference in experiences among the students, post-docs, and professors has been striking to me in terms of the paths they took to get where they are,” he adds. “I have learned much—in such a short time, it seems—that had not been clear to me before this cruise, even as an upcoming fourth-year student,” he says. “As someone questioning whether grad school is the right path, this experience has been invaluable in helping me understand what that might mean.”

The experience immersed Schuhmann in science, giving him skills that will be valuable no matter what career path he pursues, says Claire Till. 

Even amid their rigorous schedules, the team also experienced moments of quiet wonder, between sailing by volcanoes and sightings of whales, flying fish, and squid. 

Now back on land, they’ve returned with more than 400 seawater samples ready for analysis. Those samples will help reveal how nutrients move through the ocean and sustain life in the Galápagos, one of the world’s most renowned marine ecosystems, and beyond.

“There’s nothing like seeing the Galápagos up close—the islands, the wildlife, the ocean currents—and knowing the data we collect here will help protect this extraordinary place,” says Claire Till.