Experimentation on the Coastal Marine Habitat Restoration through Ecological Engineering: Creation and Test of Coastal Nurseries in the Mediterranean

The degradation of coastal marine habitats and biodiversity loss pose significant ecological challenges, requiring restoration efforts. In June 2024, the European regulation on nature restoration established a framework for managing and restoring these ecosystems. To address the scale of this task and limited experimental resources, the CREANURS program, led by the University of Corsica, was launched to test micro-habitat prototypes targeting key marine species. The project aims to enhance scientific and technical knowledge to optimize the restoration of small coastal habitats in the Mediterranean. Six types of micro-habitat prototypes were designed and tested in situ at the port of Porticciolo (Haute-Corse, France). Monitoring included structural changes, colonization by fauna and flora, and acoustic characterization. Results showed most prototypes lacked sufficient physical resistance to exceptional storms, limiting monitoring duration. Biological colonization results were mixed; most micro-habitats were less effective than natural environments for mobile fauna. However, the FracFoam prototype showed promise as a shelter for a diverse detritivorous benthic community, similar to that associated with Posidonia litter. Acoustic monitoring revealed a rich benthic biophony, ranking the site among the most efficient in the French western Mediterranean. Despite heterogeneous results and environmental constraints, FracFoam stands out with an estimated 80% efficiency for restoring degraded benthic habitats, offering new perspectives for facilitating natural Posidonia colonization.