Climate change significantly impacts ocean ecosystems, underscoring the need for advanced monitoring and modeling tools. While physical and chemical parameters are increasingly well studied, biological components, especially plankton, remain difficult to assess at societally relevant spatial and temporal scales. Plankton, vital to marine food webs and global carbon cycling, exhibit extreme variability over short distances and times due to dynamic ocean features such as fronts and eddies. Current sampling methods lack the resolution to capture this variability, limiting our understanding of ecosystem health and resilience. AQUASPECT aims to address these gaps by developing and deploying the UVP6m, a new imaging sensor that extends the capabilities of the established Underwater Vision Profiler 6 (UVP6) to smaller plankton and particles (10–1000 µm). This innovation enables high-resolution, in situ imaging of plankton across a broad size range, essential for monitoring biodiversity and ecosystem function. The project integrates UVP6m and UVP6 into regional Digital Twins of the Ocean (DTOs) across three study sites: the Belgian North Sea, Western Baltic Sea, and Balearic Sea. Each site supports different objectives, including MSFD indicator development, stakeholder engagement, and mesoscale dynamics analysis. Data collected will be processed via automated pipelines and stored in FAIR-compliant platforms like EcoPart and EcoTaxa, facilitating analysis and integration with physical and biogeochemical data. AQUASPECT provides scalable methodologies and tools for regional DTOs, enabling early warnings for ecosystem stress and enhancing support for marine management and policy decisions. The project sets a foundation for harmonized, high-resolution biological monitoring across Europe’s seas. The main objectives of AQUASPECT are to: 1. Improve plankton imaging technology, through the commercialisation of a new version of the UVP6 targeting smaller sizes, the UVP6m (count from 10µm, image from 100µm) 2. Augment existing monitoring efforts with high spatial or temporal resolution sampling of plankton using imaging, in three contrasting environments (the oligotrophic Mediterranean Sea, the eutrophic North Sea and the low salinity Baltic Sea) 3. Integrate large datasets of EBVs and concomitant environmental data, into regional DTOs, as well as the European DTO (EDITO) 4. Provide more relevant information to stakeholders relative to biodiversity, carbon export, ecosystem state indicators, and effects of anoxia, through these regional DTOs.