County Wildife Site Criteria for Cornwall Appendices

ESTUARINE ROCKY HABITATS PHTGeneral DescriptionThis habitat encompasses rocky habitats in estuaries which are found from just above high water tothose which are found just below low water. Estuarine rocky habitats incorporate substrata typessuch as bedrock and stable boulders. Generally rias are one of the most relevant types of inlet forrocky estuarine habitats. Estuarine rocky habitats, along with a complex of other estuarine habitats,are part of the ‘connectivity’ of land, estuary and open sea.For example, the rich and sheltered waters of estuaries provide nursery grounds for fish, andestuarine rocky habitats are an important component of these nursery grounds.The communities on subtidal estuarine rocky habitats are equally variable and at the most diverse endof the scale. The native oyster, a UK BAP priority species, can be associated with estuarine rockyhabitats.The area of this habitat in Cornwall is thought to be at least 60 ha of which at least 50ha is found inthe Fal and Helford Rivers, but further research is needed to ascertain the area of the subtidalcomponent.National ContextThere is no published figure for the area of this habitat. The UKBAP describes it as a comparativelyuncommon feature in estuaries, mostly found in the north and western UKArea of PHT in Cornwall (ha): 60(unknown) % National TotalNumber of polygons: unknownThe habitat is: Very rareDistribution by Administrative DistrictDistrict P K CK R CN NC ΣNumber 0 nk nk nk nk nk nkArea (ha) 0 >20 >30 2 6 1 >59Distribution by Natural AreaDistrict Pe Lz CKG BM Cu ΣNumber 0 nk nk 0 0 nkArea (ha) 0 >9 >50 0 0 >59For this habitat we will take all areasAppendix 4 - Information Relating to Priority Habitat TypesCounty Wildlife Sites Criteria