Bottom-up assembly of international multiscale forces for planetary ocean biology

The 'Plankton Planet' (P2) program aims to implement, by 2030, a participative, global and continuous measurement of the surface ocean microbiome(s), enabling us to know its biodiversity, to monitor and understand its ecology and evolution, in order, for example, for exemple to incorporate its complexity and dynamics into models of the Earth system and assess ocean response to a variety of forcings and stressors. The scientific quality of P2 measurements is ensured by the effective use of novel, relatively inexpensive instruments that are easy to deploy in the field and enable the generation of high-quality consistent data on the genetic and morphological biodiversity of plankton, shared in international databases. Run by a public/private consortium of academic researchers, engineer/entrepreneurs, and seatizens (sea farers and sea users), P2 has a multi-scale and multi-community, instrument deployment strategy aimed at unlocking the major scientific, technological, legal and cognitive barriers to planetary biology. Modular workshops are at the core of this strategy, during which the use of standardized instruments and protocols, from plankton harvesting to the production of biodiversity data and contextual parameters, to data analyses, interpretation and sharing, are taught to the future ‘planktonauts’. Three deployment axes are developed. I. Academy/Navy(s) partnership.  As part of the ‘mission Bougainville’ project, since 2023, 6 Sorbonne University postmaster students per year, have been serving as Biodiversity Officers on French Navy vessels patrolling the EEZs around the islands of la Reunion, New Caledonia and Tahiti. In axis I, The P2 protocols are thus deployed in highly controlled conditions with highly trained individuals, across comprehensive spatio-temporal scales of the Indo-Pacific bassin. II. International Network of marine stations.  As part of the European BIOcean5D program, 50 P2 kits are deployed in some 40 Marine Biological Stations along Europe's coasts, from Finland to Greece. Colleagues invited to the workshops are scientists, researchers and engineers. They are invited to use the instruments on their regional themes, encouraged to co-develop measurement programs with civil society, and required to participate in a regular intercalibration exercise. Axis II brings to P2 a stable and distributed scientific base, while generating a measurement on coastal ecosystems, whose complexity requires strong local knowledge.  III. Network of sailboats and cargo ships.  Thousands of ships are constantly crossing the oceans. Equipping even 3% of this fleet would enable global measurement of plankton in the ocean's surface layers. In the original P2-Pilot Project and AtlantEco EU programs, we have been able to equip some 30 sailboats and demonstrate that sailors are ready and able to collect reliable samples and data on a planetary scale. Axis III is the ultimate way toward the ambitious goal of a participative and continuous measure of the ocean microbiome, which can only be achieved when an instrument and its data flow are sufficiently simple and operational for non-expert crews to handle and apply.