National Survey and Assessment of the Conservation Status of Irish Sea Cliffs
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NNaattiioonnaall ssuurrvveeyy aanndd aasssseessssmmeenntt ooff tthhee ccoonnsseerrvvaattiioonn ssttaattuuss ooff IIrriisshh sseeaa cclliiffffss Irish Wildlife Manuals No. 53 National survey and assessment of the conservation status of Irish sea cliffs October 2011 Simon Barron, Aoife Delaney, Philip Perrin, James Martin & Fionnuala O’Neill. Botanical Environmental & Conservation Consultants Ltd. 26 Upper Fitzwilliam Street Dublin 2. In association with Citation: Barron, S.J., Delaney, A., Perrin, P.M., Martin, J.R. & O’Neill, F.H. (2011). National survey and assessment of the conservation status of Irish sea cliffs. Irish Wildlife Manuals, No. 53. National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Dublin, Ireland. Cover photo: Arklow Head © Simon Barron The NPWS Project Officer for this report was: Karen Gaynor; [email protected] Irish Wildlife Manuals Series Editors: N. Kingston & F. Marnell © National Parks and Wildlife Service 2011 ISSN 1393 – 6670 Irish sea cliffs survey _________________ Contents Executive Summary ........................................................................................................................................ 2 Acknowledgements ........................................................................................................................................ 5 Introduction ..................................................................................................................................................... 6 Sea cliffs in Ireland ...................................................................................................................................... 6 Definition of a sea cliff ................................................................................................................................ 7 Vegetation studies and classification of sea cliffs ................................................................................... 7 Species associated with sea cliffs in Ireland .......................................................................................... 12 Conservation status of Irish sea cliffs ..................................................................................................... 13 Aims and objectives .................................................................................................................................. 15 Methodology ................................................................................................................................................. 16 Overview .................................................................................................................................................... 16 Desk study methodology ......................................................................................................................... 17 Field study ................................................................................................................................................. 24 Conservation status assessment .............................................................................................................. 36 Data management ..................................................................................................................................... 44 Vegetation analysis ................................................................................................................................... 47 Results ............................................................................................................................................................ 50 Desk survey ............................................................................................................................................... 50 Field survey ............................................................................................................................................... 57 Conservation status assessments ............................................................................................................ 71 Vegetation analysis ................................................................................................................................... 82 Discussion ...................................................................................................................................................... 91 Desk study ................................................................................................................................................. 91 Field study ................................................................................................................................................. 92 Critical assessment of methods used.................................................................................................... 100 Recommendations for future survey work ......................................................................................... 106 Conclusions .................................................................................................................................................. 113 Current threats to Irish sea cliffs ........................................................................................................... 113 General Conclusions ............................................................................................................................... 113 Bibliography & Relevant Literature ......................................................................................................... 115 Appendix I: Desk study parameters......................................................................................................... 118 Appendix II: Field recording sheets ......................................................................................................... 120 Appendix III: Positive and negative indicator species .......................................................................... 127 Appendix IV: impacts and codes for future prospects assessment ...................................................... 129 Appendix V: Site 03007 data records........................................................................................................ 138 Appendix VI: Inventory of sites in database ........................................................................................... 151 Appendix VII: Database Data Model ....................................................................................................... 158 Irish sea cliffs survey _________________ Executive Summary Sea cliffs are steeply sloping land formations on the coast, the base of which occurs in the intertidal zone. They are one of the least modified habitat types occurring in Ireland and support highly diverse vegetation communities, ranging from bare rock communities through to wooded slopes. The habitat is included on Annex I of the EU Habitats Directive as the habitat type Vegetated sea cliffs of the Atlantic and Baltic coasts (1230). This is the first systematic national survey of sea cliff vegetation and conservation status in Ireland. The research carried out here will provide baseline data for future habitat studies and a starting point for a comprehensive classification of sea cliff vegetation. In addition, the findings of this study will be used in reporting on the conservation status of Irish sea cliffs to the European Commission under section 17 of the Habitats Directive. All of the sea cliffs on the Irish coast can be considered to correspond to the EU Annex I habitat Vegetated sea cliffs of the Atlantic and Baltic coasts (1230). Under Article 17 of the Habitats Directive, the Irish State is required to monitor the conservation status of Annex I habitats occurring within the state, and to provide a report on these habitats to the European Commission every six years. As part of this project a desk study was completed on 196 sea cliff sites. Factors such as structure, vegetation and anthropogenic influences were investigated using aerial photographs, oblique photographs of the coast and a range of GIS data. All of the results presented in the report are calculated on the basis of the cliffs present in the database and does not include sites which have only been provisionally identified or those for which no photographic imagery was available. It was found that sea cliff habitat covers 22% of the coastline of Ireland and is primarily distributed along the southern, western and northwestern seaboards. A total of 177 (90%) cliff sites are at least partly within a National Parks and Wildlife Service conservation site, though soft cliffs were found to be under‐represented in the network of sites. Candidate Special Areas of Conservation (cSACs) coincide with 135 sites, Special Protection Areas (SPAs) coincide with 100 sites, proposed Natural Heritage Areas (pNHAs) coincide with 150 sites and Nature Reserves coincide with 5 sites. Sites designated as being of conservation importance often coincide with only part of a cliff site. Anthropogenic influences, which were recorded within and adjacent to cliffs, were noted at 58% of sites. Data collected during the desk study were entered into a specifically designed database along with the information available for a further 20 sites for which a desk study was carried out as part of the pilot studys for thi project (MERC/EirEco, 2009). An additional 140 sea cliff sites were provisionally identified