This factsheet presents DUC3: Assessing pelagic biodiversity and human impact, one of the Demonstrator Use Cases (DUCs) developed within the DTO-BioFlow project. It is intended for marine monitoring programmes, environmental agencies, and research institutions contributing to ecosystem assessments and reporting under the Marine Strategy Framework Directive (MSFD). DUC3: To combine plankton imaging, genetic and traditional monitoring data to improve the assessment of pelagic ecosystem health and cumulative human impacts. The Demonstrator Use Cases (DUCs) are at the core of DTO-BioFlow, showcasing how biodiversity observations, AI models, and the Digital Twin of the Ocean (DTO) can deliver digital solutions for marine sustainability.