Data exchange and integration: Use cases for EMODnet Chemistry

The European Marine Observation and Data Network (EMODnet) is the gateway to multidisciplinary marine in-situ data and data products and has been funded by the European Commission for 15 years. In particular, EMODnet Chemistry collects and makes freely available nearly 1,300,000 million metadata entries and related datasets on seawater quality in various matrices.The aim of this contribution to the EGU is to illustrate this long-term initiative of the European Commission and its wealth of use cases. These show how data fairness can enable faster and more accurate modelling and solutions to pressing global environmental emergencies. 
The EMODnet Chemistry data infrastructure supports the development of evidence-based knowledge on eutrophication, ocean acidification and contaminants, including marine litter. The measurement data are accessible via a data discovery and access service and are regularly aggregated, harmonised and validated to create thematic data collections and associated data products. Subsets of the data collections can be downloaded via the webODV explorer and extractor tool, which also allows users to create customisable data analyses and visualisations. The functioning of EMODnet Chemistry relies heavily on SeaDataNet: a pan-European marine data management infrastructure involving 110 national oceanographic data centres, which has developed consolidated services, standards and best practises. 
Over the years, EMODnet Chemistry has collected dozens of success stories about different types of data providers and data users who were willing to open up their data and use them for many purposes. Data providers include marine research institutes, environmental agencies, government marine managers from EU Member States dedicated to marine monitoring and/or marine science, ICES, the Copernicus Marine Service (CMEMS) and citizen scientists.
In terms of data users, the European Environment Agency, the EC Joint Research Centre and most of the Regional Sea Conventions have made extensive use of EMODnet Chemistry data for the implementation of the European Union's marine policy. Researchers and CMEMS use this data source to develop tools, data products and models to assess the state of the environment and trends. More recently, the partners of the Horizon Europe Blue Cloud 2026 project, which supports the implementation of the European Open Science Cloud, have used EMODnet Chemistry data together with data from CMEMS and the World Ocean Database. The objective is to develop a toolbox to create customisable, validated datasets on Essential Ocean Variables of eutrophication and assess the consistency of the information. Based on these data sources the Project is also developing tools for calculating online metocean information and indicators of the environmental quality of the Mediterranean and global oceans. Finally, EMODnet together with CMEMS is providing the data backbone for EDITO: the core infrastructure of the European Digital Twin of the Ocean, which aims to facilitate the development of applications for the digital twin.

In conclusion, EMODnet’s work, although focused on European Union data sources, is increasingly relevant to support the implementation of agreements and data services at a global level. This contribution will continue and hopefully be expanded in the coming years to increase the global marine knowledge