How the largest migration on Earth might help combat climate change

October 17, 2022
Alexis Bahl (credit: Junyi Sun)

Alexis Bahl, PhD candidate in oceanography at UBC’s Department of Earth, Ocean and Atmospheric Sciences and the Institute of Oceans and Fisheries, and three other UBC scientists have set out for an expedition to the Southern Ocean to study how salps, a type of tiny gelatinous zooplankton, can help remove carbon from the atmosphere. Along with 40+ additional scientists with different areas of focus, the UBC team boarded the Alfred Wegener Institute’s Polarstern icebreaker on October 1st and they will come back on November 17th. Scroll down to watch our interviews with Alexis and Dr. Pakhomov.

Salps travel from deep in the ocean to the surface at night and return to the cold-water depths upon sunrise, forming the world’s largest migration. “This migration, it occurs when the sun sets, and then they go up to the surface and feed on phytoplankton, which are rich in carbon. So the salps, by proxy, are rich in carbon. And then when the sun rises, they move back down to the depths to decay,” said Alexis. “So they swim down and excrete, effectively transporting carbon to the sea floor where it’s stored for centuries. Because the Southern Ocean stores about 40 per cent of global carbon, it’s important to understand how much of a role this organism will have in mitigating climate change.”

Alexis is part of the macrozooplankton and micronekton team in this journey. Funded by the National Geographic Society, the team is led by EOAS UBC professor Evgeny Pakhomov and comprised of Lora Pakhomov, Alexis Bahl, and Florian Lueskow, with a particular interest in collecting the most abundant tunicate species in the Southern Ocean.

Read more:

Alexis' expedition blog:
Vancouver Sun: UBC researchers embark on voyage to study how climate change affects tiny ocean creature
Radio Canada: 48 jours en Antarctique pour photographier la salpe, un plancton voyageur
Early Career Ocean Professionals: Alexis Bahl: an ECOP exploring salps in the southern ocean
UBC news: How the largest migration on Earth might help combat climate change