Uniting Forces: Oceanic Flux Program and Plastic Ocean Project Team Up to Investigate Particles in the Sargasso Sea

Since 1978, the Oceanic Flux Program (OFP), funded by National Science Foundation, has been crucial in enhancing our understanding of the ocean’s "biological pump"—the process by which carbon and other materials are transported from the surface to the deep ocean. By maintaining the longest continuous time series of deep ocean particle fluxes, the OFP provides invaluable data on the interactions of ocean physics, biology, and chemistry in the North Atlantic’s Sargasso Sea.

The OFP mooring, southeast of Bermuda, features sediment traps at depths of 500 meters, 1500 meters, and 3200 meters, collecting sinking particles every two weeks. The subsurface mooring also includes instruments for measuring temperature, salinity, and oxygen, as well as an upward facing Acoustic Doppler Current Profiler (ADCP) that monitors ocean currents and eddies from the surface to 300 meters deep.

In February 2024, after serving on the OFP team since 2016, Rut Pedrosa Pàmies became the lead Principal Investigator, succeeding Maureen Conte who led the program since 1994. The OFP is currently based at the Marine Biological Laboratory’s Ecosystems Center in Woods Hole, MA.

Each spring and fall, the OFP team sets sail aboard the R/V Atlantic Explorer from the Bermuda Institute of Ocean Sciences (BIOS). While the primary goal of these OFP cruises is to recover and redeploy the mooring collecting deep ocean particulate matter, they also offer valuable sampling opportunities for collaborative researchers and students. This complementary sampling is often conducted at the nearby Bermuda Atlantic Time Series (BATS) site that has been studying the upper ocean biogeochemistry since 1988.

In April 2024, the OFP team (Rut Pedrosa Pàmies, JC Weber, and Chase Glatz) welcomed the Plastic Ocean Project (POP) team. Led by Bonnie Monteleone, the team included POP researchers Kayla West and Emily Mulvihill, University of North Carolina oceanography undergraduate Emily McGee, videography major Ashley Reep, and Ethan Cruz, a high school student from a Bronx high school who also serves as a POP Global Ambassador.

POP is dedicated to reducing plastic pollution in the ocean through research, education, outreach, and interdisciplinary collaboration. This student-driven field experience has not only empowered many students over the years but has provided over 60 microplastic surface samples near the OFP site in 2009, 2010, 2012, 2013, and 2014, and most recently 2024.

Microplastics often enter marine environments through rivers, runoff, and discarded waste, making ocean surface studies essential for understanding how these pollutants travel and accumulate in oceanic gyres, such as the Sargasso Sea. With guidance from the OFP team, the students that participate with the POP team learned about oceanographic instrumentation, research vessel operations, and deep-sea moorings. They also gained insights into the impact of plastic pollution on marine ecosystems.

The April 2024 OFP cruise allowed students to immerse themselves in cutting-edge oceanographic research while actively participating in addressing global environmental challenges. They not only learned about OFP techniques for studying deep ocean particle flux but also collaborated with the POP team to collect samples via ocean surface trawls and analyze microplastic particles using micro-Fourier-Transform Infrared spectroscopy, creating a rich, hands-on learning experience that bridged theory and practice.

This collaboration also yielded a wealth of outreach material. The microplastic data collected will contribute to ongoing research and awareness campaigns, while videographer Ashlee Reep documented the experience to help raise public awareness about ocean plastic pollution. These outreach efforts are critical in inspiring action to reduce plastic waste and protect our oceans.