Mission Bougainville

A BSAOM of the French Navy, participating in Mission Bougainville

In 2021, following their meeting, Colomban de Vargas and Christophe Prazuck (director of the Ocean Institute at the Sorbonne University Alliance) envisioned a scientific expedition based on the Plankton Planet program, directly involving the French Navy and students from Sorbonne University (SU). A true scientific, human, and environmental adventure, Mission Bougainville was born. Its goal? To study the marine microbiome in remote and rarely sampled areas of the Indian and Pacific Oceans by 2030. Thanks to the participation of French Navy vessels patrolling these oceans around France’s overseas maritime territories, Plankton Planet is now able to provide multi-year, planet-wide data.

Its implementation was orchestrated between 2022 and 2023. The goal was to test the feasibility of the project on a vessel based in Brest, assemble a cross-disciplinary working team, establish the partnership between the French Navy and Sorbonne University (SU), prepare an operational schedule, secure financial resources (OFB, Naval Group, Veolia), and list the necessary equipment. A two-year pilot phase was approved for the mission, running from October 2023 to September 2025. Between March and September 2023, following the recruitment of the first cohort, four SU Master’s students trained to become Voluntary Officer Cadets (VOAs) specializing in Biodiversity—undergoing both scientific training with the Plankton Planet team and military preparation at the Naval Academy. They were then assigned to the BSAOM patrol vessels Champlain (La Réunion) and D’Entrecasteaux (New Caledonia) until September 2024. One year later, the second cohort of VOAs was deployed, consisting of five SU students and one MNHN student. This new group expanded the mission’s scope to include French Polynesia, aboard the BSAOM Bougainville, in addition to the existing locations. As of today, these six VOAs are actively engaged in the mission.

“Action” means sampling plankton as many times as reasonably possible aboard the BSAOM, then observing it on-site with the Curiosity microscope and analyzing it through quantitative imaging using the PlanktoScope (Villefranche). At the same time, biomass cakes are prepared using the Lamprey, preserved, and later sent to France for DNA content analysis via metabarcoding and sequencing (Roscoff). “Action” also means recording the geolocation of the sampling site and measuring the surrounding physicochemical parameters using appropriate sensors (Maine). Of course, since these VOAs are aspiring officers, they also have military duties on board and must meet the needs of their crews under the direction of the patrol ship’s commanding officer. The sampling schedule is determined based on their daily planning and the navigation plan. Each BSAOM has two alternating crews, meaning that the VOAs assigned—one per crew—take turns to ensure continuous sampling, with an objective of approximately 170 samples per BSAOM in the first year. The VOA on land is responsible for finalizing the organization of the data collected at each sampling station, processing it, and ensuring optimal transmission to the corresponding scientific teams.

The management of the Mission is coordinated between the Institut de l’Océan and the Sorbonne University station in Roscoff, in collaboration with the French Navy’s General Staff and the Sorbonne University Foundation. Scientific monitoring is conducted from France and remotely by our team, primarily between the Sorbonne University stations in Roscoff and Villefranche-sur-Mer, as well as the University of Maine, in interaction with the French Navy. After a first year of adjustments at all levels, the Bougainville team has been strengthened in Roscoff, Villefranche, and Banyuls to optimize the monitoring of the VOAs, while its expertise has significantly improved. This ongoing second year will allow for the implementation of usable data and the extraction of initial results. Key focus areas: abundance, biodiversity, spatiotemporal dynamics, seasonal variations, island effects, and ecosystem relationships.

In parallel with their maritime and scientific activities, the VOAs also have a role in raising awareness about plankton, both at sea and on naval bases, alongside their crew partners. On land, they are tasked with engaging with the public, including schoolchildren and decision-makers. They present Mission Bougainville and the Plankton Planet program through an educational workshop based on the work developed during numerous Plankton Planet workshops using the Curiosity Microscope.

An important point is that, following the first mission, the French Navy has expressed its commitment to continuing the project with 2030 in sight. On the Plankton Planet side, Mission Bougainville represents an incredible opportunity to take its engagements and expertise to a new level. The benefits will extend to scientific discoveries, participatory marine projects, tool development, sample and data management, public outreach, and the strengthening of the Seatizens for Plankton Planet Association, which already includes a large part of the mission’s supervisory team and the VOAs from both cohorts.

You can follow the VOAs’ logs on the LinkedIn page of the Institut de l’Océan 🡕 and/or on ours 🡕.