Tropical Atlantic Deoxygenation: gateway dynamics, feedback mechanisms and ecosystem impacts

The Make Our Planet Great Again project “Tropical Atlantic Deoxygenation: gateway dynamics, feedback mechanisms and ecosystem impacts (TAD)” started in 2019 to establish a sustained observation and modelling system for plankton and particle dynamics in the Eastern Tropical Atlantic. It focused on how equatorial current dynamics and biological oxygen demand shape oxygen distribution, carbon fluxes, and marine habitats in a region vital for fisheries and food security. Despite COVID-19 disruptions, TAD successfully deployed Underwater Vision Profilers on research vessels, moorings, and BGC-Argo floats, collecting more than a thousand high-resolution plankton and particle profiles. Three floats delivered unique year-long datasets from contrasting Atlantic environments, proving the feasibility of autonomous optical observations. The project generated key scientific advances on plankton size structure, oxygen dynamics, and carbon export, resulting in numerous peer-reviewed articles and public data releases, including contributions to the Pelagic Size Structure Database. TAD supported MSc, PhD, and postdoctoral research, and strengthened French–German collaboration. It fostered an international imaging community through workshops, seminars, and outreach tools such as PlanktonID. Major outcomes include the award of a Heisenberg Professorship to Rainer Kiko at GEOMAR (www.geomar.de/rkiko) and the launch of the www.aqqua.life project, ensuring long-term continuation of TAD’s vision. The project leaves a strong legacy of datasets, methods, and networks, laying foundations for global, distributed monitoring of plankton and particle dynamics.