Collating evidence on the restoration efforts of the seagrass Posidonia oceanica: current knowledge and gaps

Abstract

Seagrass meadows are important shallow coastal ecosystems due to their contribution to enhancing biodiversity, nu-trient cycling, carbon burial, and sediment stabilisation, but the maintenance of their integrity has been threatened by several anthropogenic disturbances. Active restoration is considered a reliable strategy to enhance recovery of seagrass ecosystems, and decision making for correct seagrass restoration management requires relying on valuable informa-tion regarding the effectiveness of past restoration actions and experimental efforts.Previous experimental efforts and human-mediated active restoration actions of the slow growing seagrass Posidonia oceanica have been collated here by combining a literature systematic review and questionnaires consulting seagrass ecol-ogy experts. Overall, the poor consistency of the available information on P. oceanica restoration may be due to the wide portfolio of practices and methodologies used in different conditions, that supports the need of further field manipulative experiments in various environmental contexts to fill the identified knowledge gaps. The current situation requires an in-ternational, collaborative effort from scientists and stakeholders to jointly design the future strategy forward in identify-ing the best practices that lead to efficient restorations of P. oceanica habitat and functioning.