The Mounts Bay Marine Conservation Zone (MCZ) was designated on 29 January 2016 and covers an area of Mount's Bay south of the coast from Long Rock to Cudden Point. The 12 km² site includes the sea around St Michael's Mount and tidal reefs such as the Greeb, near Perranuthnoe, and the Long Rock. The MCZ protects habitats ranging from exposed high-energy rock on the coast to sand and muddy sand on the sea floor. The seagrass beds, "Zostera marina", mainly grow in the sub-tidal zone and are important as a nursery area for fish and shellfish, as well as a feeding area for birds. Damage from the anchors and chains from moored boats can damage the beds.