Pelagosphera, on behalf of ARPA Lazio, has completed the underwater monitoring and characterisation phase of Posidonia oceanica meadows in the Pontine Archipelago — SIC IT6000017, seabeds surrounding Zannone Island — and along the Lazio coastline between Civitavecchia and Tuscany — SIC IT6000003, seabeds between the mouths of the Arrone Stream and the Marta River. The activities were carried out as part of the Marine Strategy Framework Directive (MSFD) programme, within the European Union’s second implementation cycle, 2021–2026.