SUBSEA Cruise Fkt260303: Expedition in the South Atlantic
March 3, 2026 – April 6, 2026
The SUBSEA Part 1 expedition aboard Schmidt Ocean Institute’s R/V Falkor (too) was the first of two planned expeditions investigating nutrient cycling, productivity, and carbon export in the subtropical South Atlantic. Conducted as part of the Schmidt Sciences Ocean Biogeochemistry Virtual Institute (OBVI), the expedition brought together an international team of scientists, technicians, engineers, and students for 35 days of continuous science operations at sea.
The subtropical ocean gyres are thousands of kilometers in diameter, with an average depth exceeding 4,000 meters, making them one of Earth’s largest continuous biomes. Gyres are large, permanent circular current systems primarily driven by Earth’s global wind patterns and Earth’s rotation, and are found in each major ocean basin. While often deprived of nutrients, it is estimated that 20% of the ocean’s primary productivity occurs in the subtropical gyres, and these ecosystems may account for up to half of the global ocean carbon export to the deep sea. Understanding their biogeochemistry is required to develop a more accurate understanding of how climate change is impacting the global ocean.
During this expedition between Schmidt Ocean Institute and the Schmidt Sciences Ocean Biogeochemistry Virtual Institute (OBVI), Dr. Matthew Church of the University of Montana and a team of international collaborators investigated nutrient exchange between the photic and twilight zones within the South Atlantic subtropical gyre. While the surface waters are nutrient depleted, the waters below carry essential ingredients for sustaining life. The team studied the movement of particles and multiple factors related to primary productivity using a variety of instruments, including the R/V Falkor (too)’s CTD, drifters, gliders, floats, McLane pumps, and Wirewalker profiler. The data collected during the expedition will support a better understanding of nutrient cycling and carbon export in subtropical ocean ecosystems.
Cruise Track
Science Team
Middle row: Katie Coates, Hunter Adams, Calvin Swart, Tully Rohrer, Angelique White, Alexis Floback, Raquel Flynn, María Luz Torres Alberto, Micaela Gonella, Jason Friesen, Dailen Jeng
Front row: Jared McGourty, Susan Garcia, Esther Mak, Ricardo Letelier, Daniela Del Valle, Richelle Ellis, Alexandra Skrivanek, Deepika Sahoo
Expedition Photo Gallery
The R/V Falkor (too) transits across the South Atlantic during SUBSEA Part 1. Image Credit: Schmidt Ocean Institute.
The team deploys the first Sediment Trap of the cruise! Image Credit: Schmidt Ocean Institute.
The team deploys the Seaglider from a small boat. Image Credit: Schmidt Ocean Institute.
The Seaglider in the water! Image Credit: Schmidt Ocean Institute.
Chief Scientist Dr. Matt Church measures near-surface phosphate concentrations. Image Credit: Schmidt Ocean Institute.
Co-PI Dr. Nicholas Hawco filters water for trace metals in the wet lab. Image Credit: Schmidt Ocean Institute.
The team samples from the CTD! Image Credit: Schmidt Ocean Institute.
Looking at a micrograph of the zooplankton community retrieved from a net tow from Station 2 (imaging done by Raquel Flynn). Image Credit: Schmidt Ocean Institute.
Unloading the McLane Pumps from the new container! Image Credit: Schmidt Ocean Institute.
The team deploys the VMP Profiler. Image Credit: Schmidt Ocean Institute.
The team deploys the Wirewalker. Image Credit: Schmidt Ocean Institute.
The team deploys the productivity array. Image Credit: Schmidt Ocean Institute.
Scientists from the Subsea Part 1 expedition pose in front of the A-Frame at the aft deck of Falkor (too). Image Credit: Schmidt Ocean Institute.
Cruise Video Updates
Schmidt Ocean Institute Video Update 1
Schmidt Ocean Institute Video Update 2
Cruise News Updates
- SUBSEA Part 1 Begins in the South Atlantic
- SUBSEA Part 1: Science Operations Begin at Station 1
- SUBSEA Part 1 Week 2 Update
- SUBSEA Part 1 Mid-Cruise Update
- SUBSEA Part 1 Bloom Dynamics and Final Long Station
- SUBSEA Part 1 Returns to Port
In the Media
Livestream from R/V Falkor (too) about cruise operations. Source: YouTube, Schmidt Ocean Institute.
Instagram post. Source: Schmidt Sciences.
Instagram reel. Source: Scientific American.