COASTAL MONITORING PROJECT 2004-2006 By Tim Ryle, Anne Murray, Kieran Connolly & Melinda Swann A Report to the National Parks and Wildlife Service, Dublin. 2009 Coastal Monitoring Project Coastal Monitoring Project EXECUTIVE SUMMARY The Irish coastline, including the islands, extends to 6,000 kilometres, of which approximately 750 kilometres is sandy. The sand dune resource is under threat from a number of impacts – primarily natural erosion, changes in agricultural practices and development of land for housing, tourism and recreational purposes. This project, carried out on behalf of the National Parks and Wildlife Service (NPWS), is designed to meet Ireland’s obligation under Article 17 of the EU Habitats Directive, in relation to reporting on the conservation status of Annex I sand dune habitats in Ireland. The following habitats were assessed: 1210 – Annual vegetation of driftlines 1220 – Perennial vegetation of stony banks 2110 – Embryonic shifting dunes 2120 – Shifting dunes along the shoreline with Ammophila arenaria 2130 – Fixed coastal dunes with herbaceous vegetation (grey dunes) 2140 – Decalcified fixed dunes with Empetrum nigrum 2150 – Atlantic decalcified fixed dunes (Calluno-Ulicetea) 2170 – Dunes with Salix repens ssp. argentea (Salicion arenariea) 2190 – Humid dune slacks 21A0 – Machairs The project is notable in that it represents the first comprehensive assessments of sand dune systems and their habitats in Ireland. Over the course of the three field seasons (2004-2006), all known sites for sand dunes in Ireland were assessed (only 4 sites were not visited owing to access problems). The original inventory of sand dune systems by Curtis (1991a) listed 168 sites for the Republic of Ireland. During the current survey, analysis of aerial orthophotographs and additional information supplied by NPWS staff increased the site list to 181 sites. In addition, 15 sub-sites are recognised on the basis that they are geographically isolated from the main site and are subject to different management regimes. Detailed site reports provide a clearer understanding of the habitat area, processes and impacts and the conservation status of the sand dune habitats at individual sites. These site reports are located in Volume II of this report. In addition, all of the results have been entered into a Coastal Monitoring Project database, which will enable a convenient method of accessing specific data. The overall condition of each habitat was determined following a methodology that was adapted from the Joint Nature Conservancy Council – Common Standards Monitoring (CSM) guidance documents. The specific attributes that determine the conservation status of a habitat at a site are (a) Habitat extent (area), (b) Structure and Functions and (c) Future Prospects. Habitat area is based on survey work using GPS, examination of aerial photographs and the production of detailed GIS maps. Structure and Functions was determined from monitoring stops that were carried out in all habitats and at most sites. Future Prospects are based on apparent impacts/threats to the site or a particular habitat that are likely to occur in the future. Each of these attributes are assigned either a ‘Favourable’, ‘Unfavourable-Inadequate’ or ‘Unfavourable-Bad’ rating, using criteria outlined in chapter 2. The final Conservation Status is a synthesis of all the collected data, none of which should be Coastal Monitoring Project used isolation. It is derived using the least favourable attribute. In addition, the overall conservation assessment of habitat takes into account the overall range of the habitat within a biogeographical region. A summary of the number of sites achieving each overall conservation status rating for each habitat is provided below. Number of Sites Habitat Names Total no. Favourable Unfavourable- Unfavourable- of Sites inadequate bad Decalcified fixed dunes with 4 3 1 0 Empetrum nigrum (2140) Annual vegetation of driftlines 71 46 25 0 (1210) Perennial vegetation of stony banks 47 26 20 1 (1220) Embryonic shifting dunes (2110) 116 38 51 27 Shifting dunes along the shoreline 141 27 60 54 with Ammophila arenaria (2120) Fixed coastal dunes with 152 20 89 43 herbaceous vegetation (2130) Atlantic decalcified fixed dunes 7 4 3 0 (2150) Dunes with Salix repens ssp. 17 8 9 0 argentea (2170) Humid dune slacks (2190) 64 21 33 10 Machairs (21A0) 59 6 35 18 The overall conservation status rating is determined by a combination of the assessments for Range, Habitat area/extent, Structure and Functions, as well as Future Prospects. A summary of the ratings achieved by each habitat in each category is provided in the table below, where green = Favourable, amber = Unfavourable- Inadequate and red = Unfavourable-Bad. Range Although a number of new sites were recorded for certain habitats, while others were declassified, these changes did not have a significant impact on the range of any particular habitat. Furthermore, as this is predominantly a baseline survey, it is assumed that habitat range is stable and so this attribute is considered to be favourable for all habitats. Habitat area/extent Previous estimates for the extent and distribution of a number of habitats were found to be inaccurate, partly due to mapping errors and misclassification of the vegetation. In many cases, this made it difficult to ascertain if there was an actual loss or gain in the current survey. With the exception of decalcified dunes with Empetrum nigrum (which were favourable) and mobile dunes (which were unfavourable-bad), the area of all habitats are all considered to be unfavourable-inadequate, indicating that there has been some loss of habitat. A standard mathematical formula was applied to the data to estimate habitat loss, except where losses could be quantified e.g. loss of habitat to a golf course development. Coastal Monitoring Project National Overview of Conservation Assessments Habitat Names Range Area Structure Future and Prospects Overall Functions Decalcified fixed dunes with Empetrum nigrum (2140) Annual vegetation of driftlines (1210) Perennial vegetation of stony banks (1220) Embryonic shifting dunes (2110) Shifting dunes along the shoreline with Ammophila arenaria (2120) Fixed coastal dunes with herbaceous vegetation (2130) Atlantic decalcified fixed dunes (2150) Dunes with Salix repens ssp. argentea (2170) Humid dune slacks (2190) Machairs (21A0) Structure and Functions While most coastal habitats are naturally dynamic, a functioning coastal ecosystem must have the capacity to adapt to pressures, both natural and anthropogenic. Overall, only the decalcified fixed dunes with Empetrum nigrum and annual vegetation of driftlines were assessed as favourable for structure and functions, indicating that the natural process for this habitat are functioning unhindered. At all other sites, this attribute is considered unfavourable-inadequate or unfavourable-bad in the case of mobile dunes, fixed dunes and machairs, indicating human impacts, such as land use and management, along with either overgrazing or undergrazing are negatively impacting on the habitats. Future Prospects For six of the habitats assessed during this survey, the future prospects have been rated as unfavourable-inadequate, the remainder being assessed as unfavourable-bad, which is largely due to ongoing negative impacts which are likely to continue into the future. The main reasons appear to be restructuring of land holdings and agricultural improvement, overgrazing, and general recreation. These negative impacts, coupled with natural erosion, which although considered to have a neutral impact, are likely to continue into the future and active management will be required to remedy the situation in order to achieve favourable conservation status. Overall Conservation Assessment The national overview of sand dune habitats highlights the worrying fact that the overall conservation assessment in 6 of the 10 habitats is unfavourable-inadequate, while the remaining four are rated as unfavourable-bad, including two of the priority dune habitats. Coastal Monitoring Project The following conclusions can be made regarding the overall findings at each habitat, which are arranged in order of best conservation status to worst. • Decalcified fixed dunes with Empetrum nigrum (2140) was recorded from 4 sites in Donegal. It is estimated that the habitat covers 2.85ha, which is significantly lower than the 245.01ha reported in the NATURA 2000 database. The reason for this discrepancy is partly owing to misidentification of the habitat in earlier surveys (e.g. Empetrum was present, but was not growing on sand), its occurrence within complex mosaics of vegetation and more accurate mapping. The overall conservation assessment for this habitat is unfavourable-inadequate. Issues relating to habitat characteristics and demarcation - in terms of other similar “heath”-like habitats were not resolved during the current project and will require additional research. Despite these difficulties, 3 sites (or 99% of the total habitat area) were rated as favourable, while the last, small site accounts for 1% unfavourable-inadequate overall conservation assessment in terms of area. Future work is needed to clearly define, describe and develop a management strategy for this habitat in Ireland. • Annual vegetation of driftlines (1210) was recorded from a total of 71 sites and occupied an area of 52.16ha. There has been an estimated loss of 0.6% or 0.31ha of the total habitat area since 1996 primarily due to natural erosion, pedestrian