France, Aug. 9 -- 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.

Recent graduates from the Sorbonne are stationed on board as biodiversity cadets. They work alongside the crew, collecting and studying plankton as the ships patrol thousands of kilometres of open sea.

One of those ships, the Champlain, sailed in June to the Scattered Islands near Madagascar...