|dc.identifier.citation||Maria P. Long, John T. Brophy, 'Monitoring of sites and habitat for three Annex II species of whorl snail (Vertigo)', [report], National Parks and Wildlife Service. Department of Culture, Heritage and the Gaeltacht, 2019-09, Irish wildlife manuals, No.104, 2019||en
|dc.description||All three Vertigo species listed under Annex II of the EU Habitats Directive and present in Ireland were surveyed over a four-year period (2014-2017) at a total of 60 sites around Ireland (21 for Vertigo angustior, 19 for Vertigo geyeriand 20 for Vertigo moulinsiana). Of these 60 sites, 54 had been subject to a monitoring survey in the period 2008-2010, while six were newly added sites. Sites were surveyed using the previous surveymethodology with some alterations. The survey involved taking spot samples across a site, recording a suite of data at each one, and repeating any transects to allow a direct comparison of habitat. Based on the amount of suitable habitat present in a defined habitat polygon, the suitability of the polygon for supporting the target species was assigned to a category on a 5-point scale running from Optimal to Unsuitable. Of the 21 V. angustior sites visited, four had an Overall conservation assessment of Favourable (green), five were Unfavourable-Inadequate (amber) and 12 were Unfavourable-Bad (red). For the 19 V. geyerisites, there were three Favourable (green), six Unfavourable-Inadequate (amber) and 10 Unfavourable-Bad (red). The result for V. moulinsiana was four Favourable (green), six Unfavourable-Inadequate (amber) and 10 Unfavourable-Bad (red). Where the calculated results, based on the assessment criteria of the baseline survey (2008-2010), seemed not to reflect the situation on the ground, expert judgement was employed to suggest an amendment to the conservation assessment status, and a review of the assessment criteria. Overall, these results represent a substantial decline in the conservation status for all three species since the 2008-2010 survey. The cause of these changes in status was principally due to the result of the Population assessment or Habitat assessment. In some cases this can be linked to changes in habitat due to pressures acting on the site (e.g. grazing regime, hydrological changes), while in other cases the cause of the decline is not clear. Differing weather patterns between the two survey periods may have played a role, while overly stringent assessment criteria were also considered to have been a factor. Management actions are suggested based on the results of the Future prospects assessment, in which pressures and threats acting on the site are identified. In recognition of the differing micro habitat requirements of the three species and the site-specific issues involved, an overly prescriptive approachwas not taken in making management recommendations. Management plans are needed at most sites, and NPWS is best placed to take the lead in their development and implementation. Stakeholder engagement is vital in implementing meaningful action at Vertigosites, rather than taking a solely top-down approach, and so landowners and land users should be involved at all stages. Particularly for grazing management, land users will be best placed to decide on stocking rates and timing, once the desired habitat outcome is clearly understood by them. While summary management action recommendations are presented in this report, the individual site reports should be read for site-specific information. Recent changes to the reporting requirements for population under Article 17 of the Habitats Directive may allow scope for simplification of the survey and assessment methodologies in the future. Recommendations are made in this report that focus on ways of simplifying and streamlining the current system, as well as generating more data on populations in a shorter time. The future of the three Annex II Vertigo species across Ireland depends on developing and implementing the necessary management plans, continued monitoring, and further research into aspects of the biology and ecology of the target species. Based on the results of this survey and on the site-based methodology employed, widespread decreases in both population and habitat quality are apparent. Furthermore, these pressures are acting on Vertigo sites against the backdrop of the threat of large-scale ecological change that may come with climate change. Without the implementation of management plans, and crucially, active management taking place on the ground, current declines are likely to continue on many of the sites. However, the fact that new sites are still being found, some existing sites have been extended, and there are sites that still have healthy Vertigo populations, shows there is still reason to be optimistic about the future of these three species in Ireland.
The NPWS Project Officer for this report was: Dr Brian Nelson; email@example.com||en