EMODnet integrates marine datasets from a variety of sources, including citizen science initiatives, once they meet interoperability and quality standards. For MCS projects, this means observations such as physical parameters (e.g., temperature, salinity), chemical measures, biodiversity sightings, and pollution data can be ingested via EMODnet Data Ingestion. Data is standardised, quality-controlled, and linked with metadata to ensure it is findable, accessible, interoperable, and reusable (FAIR). These datasets contribute to EU marine policy monitoring, environmental assessments, and modelling, while giving visibility and acknowledgment to citizen scientists. EMODnet is one key CS-MACH1 stakeholder and some of the pathways that CS-MACH1 is designing will facilitate EMODnet to handover more citizen science data.

SeaDataNet specialises in physical and chemical oceanographic parameters, providing formats, vocabularies, and tools to ensure high interoperability. For marine citizen science, this means physical measurements such as sea temperature, currents, or turbidity gathered with cost-efficient sensors can be validated and archived alongside professional datasets. The infrastructure uses standardised metadata (Common Data Index – CDI) to facilitate discovery and reuse, enabling CS data to feed into regional and global ocean observing systems. Citizen-contributed datasets that meet these standards can thus directly support marine monitoring, policy assessments, and climate studies.

EurOBIS focuses on biodiversity observations, including species presence, abundance, and distribution records from both professional and citizen science surveys. MCS projects can contribute data from activities such as underwater biodiversity monitoring, coastal transects, plankton counts, or species tagging, provided records include accurate taxonomy (often via WoRMS) and geolocation metadata. Once integrated, these datasets become part of a global biodiversity database used in research, conservation planning, and environmental impact assessments. This ensures that citizen observations directly contribute to understanding and protecting marine ecosystems.