In the framework of the European Marine Strategy Framework Directive (MSFD) and the Habitats Directive (HD), MARECO is responsible for the design and implementation of the national monitoring program on seafloor integrity and biodiversity in natural gravel bed biotopes, classified as “Reefs” (Habitat 1170) under the EU Habitats Directive. This multidisciplinary monitoring programme combines both physical sampling and remote sensing techniques to demarcate the distribution of these environments, providing the spatially explicit baseline for detailed follow-up monitoring. Samples are collected annually at selected locations, to carry out the biological evaluations of the mapped areas and to assess the environmental status of the gravel bed biotopes.