Blue-Cloud 2026 - D2.3 Optimised and expanded Blue Cloud Data Discovery & Access Service – Documentation Report

The Blue-Cloud Data Discovery and Access service (DD&AS) aims at facilitating federated discovery and access to data sets and data products as managed in a range of Blue Data Infrastructures (BDIs), which are represented by partners in the Blue-Cloud 2026 project. Several of these BDIs are European Research Infrastructures, such as SeaDataNet, EurOBIS, EuroArgo, EMSO, and others, that contribute to EMODnet Thematic services such as EMODnet Chemistry and EMODnet Physics. The Blue-Cloud DD&AS service is one of the generic services available within the Blue-Cloud VRE platform. However, as part of a recent positioning of Blue-Cloud in the marine data landscape with EMODnet and EDITO, it has been decided to consider the DD&AS for the time being as an internal data gateway for the Blue-Cloud VRE users, facilitating the developers and users of Blue-Cloud VLabs and WorkBenches to make use of data sets from established BDIs by means of common federated discovery and access. This decision was driven by the need to streamline the European marine data landscape, avoiding duplication with core infrastructures like EMODnet, and focusing Blue-Cloud's unique value on VRE-based analytical and computational workflows within the VRE thanks to federated identity and Single Sign-On. For that purpose, the DD&AS now also makes use of the Blue-Cloud AAI service, so that only registered Blue-Cloud users can undertake data shopping transactions, while giving a Single-Sign-On for all Blue-Cloud services.

The Blue-Cloud DD&AS makes use of web services and APIs, following protocols such as CSW, OAI-PMH, ERDDAP, or otherwise, as provided and maintained by the BDIs. These are used to support machine-to machine interactions for harvesting metadata, submitting queries, and retrieving resulting metadata, data sets, and data products. From the work on the initial 'beta release' of the DD&AS in the pilot Blue-Cloud project, it was learnt that there was quite a variety and difference in FAIRness of the web services in use by the BDIs. Optimisation would allow to achieve an improved FAIRness of the BDI services as well as of the overall federation as part of the DD&AS. Therefore, one of the objectives of the Blue-Cloud 2026 project deals with streamlining of BDI web services and establishing their semantic interoperability as ways for optimising the DD&AS. This will benefit each BDI to improve the FAIRness of their services. This will contribute to improving the FAIRness of the overall European marine data management landscape in which BDIs play an important role as networks reaching out to many individual research and data collecting organisations The work on the DD&AS, particularly its focus on streamlining BDI web services and achieving semantic interoperability through an expanded common metadata profile, is considered foundational. This optimization effort paves the way for the robust federation of BDIs as key pillars under the future EMODnet and EDITO data services.

In the first year, a strong basis was laid for optimising the DD&AS and its federated BDIs and for expanding the DD&AS with four additional BDIs, namely EMSO, SIOS, ELIXIR – Mgnify and EMODnet Physics. That basis was provided by the two Deliverables D2.1 - Existing DD&AS and Blue Data Infrastructures – Review and Specifications for Optimisation Report – and D2.2 - New Blue Data Infrastructures – Service Analysis Report – that were delivered in October – November 2023 with conceptual analyses, specifications and formulated actions.It has been achieved to expand the DD&AS with the four new BDIs, so that the DD&AS now federates the following BDIs:

• SeaDataNet CDI service
• SeaDataNet Data Products service
• EurOBIS service
• EcoTaxa service
• ELIXIR-ENA service
• ELIXIR-MGnify service
• EurArgo service
• EMODnet Chemistry service
• EMODnet Physics service
• ICOS-Marine service
• SOCAT service
• EMSO service
• SIOS service

Furthermore, progress has been made with upgrading of the DD&AS and web services of its federated BDIs. The common metadata profile as used in the federation and the DAB metadata broker service (managed by CNR-IIA) has been expanded with extra metadata tags, including URIs of possible used controlled vocabularies. Moreover, BDIs have worked on enriching their contents, populating more of the common metadata and uptake of controlled vocabularies in their metadata and making these actionable by including URIs in the output of web services. This process is still ongoing, but it will facilitate in a later stage semantic harmonisation. To ease mapping between different vocabularies in use by BDIs, a Semantic Analyser has been adopted, which has been initiated by NOC-BODC in the FAIR-EASE project. Using footprints of terms used by BDIs, and the knowledgebase of the semantic analyser, NOC-BODC has progressed with dedicated mappings.

Building upon the expanded DAB service, WP2 has developed a DD&AS test interface for the DD&AS which makes the use of additional terms and use of Controlled Vocabularies visible in the detail pages of data collections (level 1) and data sets (level 2). This way, the progress with publishing of use of vocabularies within the BDI web services and the uptake of vocabularies by BDIs can be followed in the DAB report (see earlier), which also gives a % of completion overall entries, and per entry in the new DD&AS test interface.

The progress made with optimising and expanding the DD&AS is reported in this Deliverable D2.3 - Optimised and expanded Blue Cloud Data Discovery & Access Service – Documentation Report. It not only documents the achievements but also open actions which will be undertaken in the coming third year to finalise the DD&AS and BDI optimisation activities.