MISTIC SEAS III aims to address the assessment of the Marine Strategy Framework Directive (MSFD) Descriptor 4 (Food webs) at the Macaronesian sub-regional level, following the criteria set up under the new Commission GES Decision 2017/848/EC. Taking advance on the coordinated actions and the cooperation frame established during the previous MISTIC SEAS projects for a commom ground for Monitoring Biodiversity, this proposal aims to operationalise th MSFD -D4, Trophic Webs, in the Macaronesian sub-region, to define a common sub-regional approach to the development of this descriptor and also strengthening the cooperation with other sub regions of the North-east Atlantic Ocean (e.g. Bay of Biscay and the Iberian Coast sub-region). This action proposes a common approach, species and metrics for Macaronesia aiming to maximize synergies between indicators, monitoring programs and measures already developed for D1 and D3 in both Member States.