Definition and rationale for ICES ecoregions

ICES uses ecoregions as the spatial units to synthesize the evidence for the ecosystem approach (ICES, 2020). They enable ICES network to monitor, assess, address, and solve regional scientific challenges (Figure 1). The ecoregions are used for geographical allocation and reporting of ICES advice. All ICES advice is now linked to an ecoregion, or a collection of ecoregions. The current ecoregions were instigated in 2015 after a process that began in 2004. ICES process of developing ecoregions has influenced many spatial management definitions and supra-national legislation (e.g. the EU Marine Strategy Framework Directive, MSFD). Once defined, the ecoregions adapt slowly and occasionally in response to changes in management areas and through dialogues with regional managers. The ICES system of ecoregions is different from the ICES fishing area system, and reflects ICES move toward providing the evidence for ecosystem-based management. The use of consolidated ecoregions enhances ICES ability to research ecosystem and social dynamics and translate those findings into consolidated ecosystem-based advice.