Survey of chalk cave, cliff, intertidal and subtidal reef biotopes in the Thanet Coast cSAC (ENRR325)

A survey was undertaken in August and September 1997. Phase 1 biotope mapping revealed 37 different intertidal biotopes/habitats. The survey identified 13 biotopes defined as rare, and four biotopes defined as uncommon in Britain. Phase 1/2 surveys at five selected subtidal sites revealed five different biotopes. Site survey maps indicating the occurrence of biotopes are presented. The best examples of natural cliff and cave formations and chalk cave and cliff algal communities remain in the Kingsgate area. There had been no loss of habitat since previous surveys. Species diversity on Thanet overall is intrinsically low due to the harsh and geologically unique environment. Intertidal and subtidal sites on the northeast and east coasts of Thanet support a greater diversity of biotopes and species. Intertidal sites at the western ends of Thanet were strongly influenced by siltation and generally less rich in biotopes and species. Phase 2/3 surveys of foreshore reef were undertaken at Fulsam Rock and Whiteness. Both sites contained a good range of biotopes typical of Thanet and chalk shores generally. Variants of nationally common biotopes characterised by ‘rock-boring’ fauna were commonly recorded at intertidal and subtidal levels throughout the cSAC. Significant incursions of the invasive alga Sargassum muticum were recorded at Fulsam Rock and along the north coast of Thanet to Palm Bay. A summer bloom of the green algae Enteromorpha and Ulva obscuring other biotopes was recorded at Fulsam Rock and elsewhere on Thanet. This may be related to inshore water quality. Turbid water conditions with low light penetration are important factors responsible for the limited and specialised subtidal flora and fauna.
A printed copy of this report is available from our Enquiry Service. Tel: 0845 600 3078 Email: enquiries@naturalengland.org.uk