The site includes vegetation which is degraded by fires and goat grazing. The seabeds are characterized by rapidly descending cliffs. The Posidonia meadow has limited coverage and appears in patchy formations. Mountcristo is an important nesting site for seabirds, associated with rocky environments, with the unique presence of Monachus monachus. The herbaceous vegetation retains floristic and phytogeographical significance despite intensive grazing. The island’s isolation, the lack of a resident population, the distance from the coast and imposed restrictions have contributed to maintain high naturalness and biodiversity in marine ecosystems. There are also extensive populations of various Cystoseira species in deeper zones. The coralligenous communities are well-structured and present throughout the island’s perimeter, with species like red and white Gorgonia.