The exploitation and the energy and climate crises are exacerbating the decline in marine biodiversity. Current EU directives and strategies, as well as the two UN Decades, provide an essential framework for marine conservation. Establishing efficient protected areas for species and habitats and at the same time using marine resources sustainably is a major challenge. The implementation of the PMC "how to stop biodiversity loss - from knowledge to action" will provide an important incentive for these discussions.