French scientists map plankton, the ocean’s mysterious oxygen factories

A large phytoplankton bloom, visible from space, shows how these drifting ecosystems can stretch across hundreds of kilometres. © European Space Agency

French scientists are mapping plankton across the Indo-Pacific – using Navy ships to study the microscopic organisms that produce half of Earth’s oxygen, feed the ocean and help regulate the planet’s carbon. The eight-year mission is charting life in remote waters to understand how these drifting ecosystems evolve – and why they matter.

Since 2022, Mission Bougainville has been turning French Navy ships into floating science labs.