Tanhua et al. Ocean FAIR Data Services formats and made available through Web services is necessary. In particular, automation of data workflows will be critical to reduce friction throughout the data value chain. Adhering to the FAIR principles with free, timely, and unrestricted access to ocean observation data is beneficial for the originators, has obvious benefits for users, and is an essential foundation for the development of new services made possible with big data technologies.

Marine data are needed for many purposes: for acquiring a better scientific understanding of the marine environment, but also, increasingly, as marine knowledge for decision making as well as developing products and services supporting economic growth. Data must be of sufficient quality to meet the specific users' needs. It must also be accessible in a timely manner. And yet, despite being critical, this timely access to known-quality data proves challenging. Europe's marine data have traditionally been collected by a myriad of entities with the result that much of our data are scattered throughout unconnected databases and repositories. Even when data are available, they are often not compatible, making the sharing of the information and data aggregation particularly challenging. In this paper, we present how the European Marine Observation and Data network (EMODnet) has developed over the last decade to tackle these issues. Today, EMODnet is comprised of more than 150 organizations which gather marine data, metadata, and data products and make them more easily accessible for a wider range of users. EMODnet currently consists of seven sub-portals: bathymetry, geology, physics, chemistry, biology, seabed habitats, and human activities. In addition, Sea-basin Checkpoints have been established to assess the observation capacity in the North Sea, Mediterranean, Atlantic, Baltic, Artic, and Black Sea. The Checkpoints identify whether the observation infrastructure in Europe Martín Míguez et al. EMODnet: Visions and Roles meets the needs of users by undertaking a number of challenges. To complement this, a Data Ingestion Service has been set up to tackle the problem of the wealth of marine data that remain unavailable, by reaching out to data holders, explaining the benefits of sharing their data and offering a support service to assist them in releasing their data and making them available through EMODnet. The EMODnet Central Portal (www.emodnet. eu) provides a single point of access to these services, which are free to access and use. The strategic vision of EMODnet in the next decade is also presented, together with key focal areas toward a more user-oriented service, including EMODnet for business, internationalization for global users, and stakeholder engagement to connect the diverse communities across the marine knowledge value chain.

Data availability is of vital importance for marine and oceanographic research but most of the European data are fragmented, not always validated and not easily accessible. In the countries bordering the European seas, more than 1000 scientific laboratories from governmental organisations and private industry collect data using various sensors on board of research vessels, submarines, fixed and drifting platforms, aeroplanes and satellites to measure physical, geophysical, geological, biological and chemical parameters, biological species and others. SeaDataNet is an Integrated Research Infrastructure Initiative (I3) (2006Á2011) in the EU FP6 framework programme. It is developing an efficient distributed Pan-European marine data management infrastructure for managing these large and diverse data sets. It is interconnecting the existing professional data centres of 35 countries, active in data collection and providing integrated databases of standardised quality on-line. This article describes the architecture and the features of the SeaDataNet infrastructure. In particular it describes the way interoperability is achieved between all the contributing data centres. Finally it highlights the on-going developments and challenges.

ENVRI-FAIR is a recently launched project of the European Union's Horizon 2020 program (EU H2020), connecting the cluster of European Environmental Research Infrastructures (ENVRI) to the European Open Science Cloud (EOSC). The overarching goal of ENVRI-FAIR is that all participating research infrastructures (RIs) will provide a set of interoperable FAIR data services that enhance the efficiency and productivity of researchers, support innovation, enable data-and knowledge-based decisions and connect the ENVRI cluster to the EOSC. This goal will be reached by: (1) defining community policies and standards across all stages of the data life cycle, aligned with the wider European policies and with international developments; (2) creating for all participating RIs sustainable, transparent and auditable data services for each stage of the data life cycle, following the FAIR principles; (3) implementing prototypes for testing pre-production services at each RI, leading to a catalogue of prepared services; (4) exposing the complete set of thematic data services and tools of the ENVRI cluster to the EOSC catalogue of services.

Access to reliable and harmonised, large quantity of data has become a key topic in different fields, especially in the oceanographic sector where the cost of data sampling is very high. A huge amount of high quality marine data not only provides a basis for estimating the likelihood of occurrence of various kinds of environmental problems, but also helps to make relevant decisions about potential uses of the oceans such as renewable-energy development, aquaculture, etc. Thus, it is important to collect and make available high quality and interoperable ocean and marine observations, both at local and at global scale over several years, this is the main objective of the SeaDataNet e-infrastructure.