Survey, habitat and population assessments for Vertigo geyeri, Vertigo moulinsiana, Oxyloma sarsi and Omphiscola glabra at selected sites Maria P. Long & John T. Brophy Survey, habitat and population assessments for Vertigo geyeri, Vertigo moulinsiana, Oxyloma sarsi and Omphiscola glabra at selected sites Maria P. Long1 & John T. Brophy2 1 Newtownshandrum, Charleville, Co. Cork 2 Botanical, Environmental & Conservation Consultants Ltd, Ground Floor Offices, Loft 31, South Cumberland St., Dublin 2. Citation: Long, M.P. & Brophy, J.T. (2013) Survey, habitat and population assessments of Vertigo geyeri, Vertigo moulinsiana, Oxyloma sarsi and Omphiscola glabra at selected sites. Report to National Parks and Wildlife Service, Department of the Arts, Heritage and the Gaeltacht, Ireland. Cover photo: Vertigo moulinsiana at Castletown, Co. Waterford (John Brophy) The NPWS Project Officer for this report was: Dr Brian Nelson; [email protected] © National Parks and Wildlife Service 2015 Rare molluscs – surveys of four species ____________________________ Contents Contents ........................................................................................................................................................... 1 Executive Summary ....................................................................................................................................... 1 Acknowledgements ....................................................................................................................................... 2 Introduction .................................................................................................................................................... 3 Background and Rationale ........................................................................................................................ 3 Report Format and Conventions .............................................................................................................. 4 Survey Locations ......................................................................................................................................... 4 Conservation Assessments ........................................................................................................................ 5 Vertigo geyeri .................................................................................................................................................. 6 Introduction ................................................................................................................................................. 6 Methodology ............................................................................................................................................... 7 Field survey ............................................................................................................................................. 7 Laboratory work ..................................................................................................................................... 9 Results and Discussion – Cooley Lough .................................................................................................. 9 Results and Discussion – Carrowmoreknock........................................................................................ 15 Vertigo moulinsiana ..................................................................................................................................... 22 Introduction ............................................................................................................................................... 22 Methodology ............................................................................................................................................. 23 Field survey ........................................................................................................................................... 23 Laboratory work ................................................................................................................................... 25 Results and Discussion – Lough Derg, near Portumna ....................................................................... 25 Results and Discussion – Castletown ..................................................................................................... 33 Results and Discussion – Strancally ....................................................................................................... 38 Results and Discussion – The Murrough ............................................................................................... 43 Rare molluscs – surveys of four species ____________________________ Oxyloma sarsi ............................................................................................................................................... 51 Introduction ............................................................................................................................................... 51 Methodology ............................................................................................................................................. 52 Field survey ........................................................................................................................................... 52 Laboratory analysis .............................................................................................................................. 54 Results and Discussion ............................................................................................................................. 54 Omphiscola glabra ....................................................................................................................................... 60 Introduction ............................................................................................................................................... 60 Methodology ............................................................................................................................................. 61 Field survey ........................................................................................................................................... 61 Laboratory analysis .............................................................................................................................. 63 Results and Discussion - Carrickavrantry ............................................................................................. 63 Results and Discussion – Brierfield ........................................................................................................ 68 Conclusion .................................................................................................................................................... 70 Bibliography & Relevant Literature ......................................................................................................... 72 Appendix I: Definitions of habitat suitability categories ......................................................................... 74 Appendix II: Aerial photographs showing sampling points .................................................................. 76 Appendix III: Grid references for sampling points ................................................................................ 107 Appendix IV: Vascular plant, habitat, and other related data .............................................................. 112 Appendix V: Bryophyte data .................................................................................................................... 129 Appendix VI: Concordance of sample numbers .................................................................................... 132 Appendix VII: Transect diagrams ............................................................................................................ 134 Appendix VIII: Polygon details ................................................................................................................ 137 Rare molluscs – surveys of four species ____________________________ Executive Summary A number of surveys were carried out between September and November 2012 for four rare mollusc species, Vertigo geyeri, Vertigo moulinsiana, Oxyloma sarsi and Omphiscola glabra. The aims of the surveys were: - to confirm the presence of the species at the chosen sites; - to assess the size and range of the population at those sites; - to document the associated molluscan species, and also the vegetation; and - to map the habitat areas used by the species, along with categorising their suitability for the species; Finally, at each site, the conservation status of the species was assessed. Nine sites were visited – two for Vertigo geyeri, four for Vertigo moulinsiana, one large composite site for Oxyloma sarsi and two for Omphiscola glabra. A total of 152 molluscan samples were taken, which resulted in 5,245 individual specimens from 47 mollusc species. Vertigo geyeri was found, albeit in low numbers, at both survey sites. The habitats recorded at both of these sites appear to be on the edge of the range of tolerance for this species, mainly in relation to the hydrological regimes. The conservation status of the species was assessed as Unfavourable – Bad at both sites. At all four Vertigo moulinsiana sites the data collected during the survey expanded the known range for the species. Favourable conservation status was