The MERLIN Web App is an interactive platform that provides a comprehensive overview of biodiversity within Natura 2000 sites across Europe. It allows users to explore protected areas, navigate between sites, and access detailed information on species and habitat types listed in Annex I and II of the Habitats Directive. Users can visualise spatial data, analyse coverage and download datasets for further scientific, policy or management applications.

A particular focus of the Web App is freshwater biodiversity, including all groundwater-dependent habitat types. This reflects MERLIN’s emphasis on freshwater ecosystems, which are among the most threatened components of European biodiversity. By highlighting freshwater habitats and their representation within Natura 2000, the tool supports improved knowledge, strategic planning and more effective conservation action.

The Web App also provides a Europe-wide assessment of restoration potential for all running and standing water habitats listed in Annex I. The restoration potential is modelled based on multiple environmental conditions relevant to conservation status (Baumane et al., in preparation) and classified into five categories: very high, high, intermediate, low and very low. This makes the tool a practical decision-support resource for Member States when developing National Restoration Plans under the Nature Restoration Regulation (NRR).

Four short instructional videos guide users through the main functions of the application and demonstrate how it can be applied in practice. Module 4 of the MERLIN Academy will also focus on the Web App as well as on the upscaling workflow.

The application is based on data from the Natura 2000 database (European Commission, 2022, version 2021). The underlying dataset is openly available via Zenodo (DOI: 10.5281/zenodo.17601833).