The five islands off the west coast of Pembrokeshire – Grassholm 9ha (22 acres), Middleholm 9ha (22 acres), Ramsey 17ha (685 acres), Skokholm 106ha (263 acres) and Skomer 316ha (781 acres) – are of national and international importance for their seabirds. In addition to this, they are of considerable botanical interest, support the largest Grey Seal colony in southern Britain, and one island hosts a unique island race of Bank Vole – the Skomer Vole. The seas around Skomer also form the only statutory Marine Nature Reserve in Wales.