Saltmarsh Monitoring Project 2017- 2018

Abstract

This report presents details of a monitoring survey conducted in the period 2017-2018 to assess the conservation status of four EU Habitats Directive Annex I saltmarsh habitats: Salicornia and other annuals colonizing mud and sand (Natura code 1310), Atlantic salt meadows (Glauco-Puccinellietalia maritimae) (1330), Mediterranean salt meadows (Juncetalia maritimi) (1410) and Mediterranean & thermo-Atlantic halophilous scrubs (Sarcocornetea fruticosi) (1420). The survey methodology used in the baseline Saltmarsh Monitoring Project (SMP) was revised in light of the work carried out by the Saltmarsh Angiosperm Assessment Tool for Ireland (SMAATIE) project in order to collect data that could be used to assess the Annex I habitats under the Habitats Directive, while also assessing the Ecological Status of the saltmarsh angiosperm Biological Quality Element for reporting under the Water Framework Directive. A total of 85 saltmarsh sites was surveyed and assessed as part of the current project, from all coasts of Ireland. This comprised 61 sites that were surveyed in the baseline SMP and 24 sites that had not previously been surveyed. A total of 29.60 km2 of saltmarsh habitat, including non-Annex I habitat, was surveyed. This included 0.14 km2 of habitat 1310, 10.95 km2 of habitat 1330, 3.61 km2 of habitat 1410 and <0.01 km2 of habitat 1420. The recorded habitat areas represent 12% (1310), 40% (1330), 38% (1410) and 84% (1420) of the target habitats mapped in Ireland. The national conservation assessments were carried out for each of the four target Annex I habitats using the results of the current survey, combined with other data sources including the SMP and Saltmarsh Function and Human Impacts in Relation to Ecological Status (SAMFHIRES). The Overall conservation assessment for 1310 was assessed as Favourable, however the Future prospects for Structure and functions was assessed as Poor at many sites due to the threat posed by potential the spread of Spartina anglica, which competes for the same niche. Therefore the extent of Spartina anglica should be closely monitored to ensure that this species is not expanding. The Overall conservation assessment for 1330 was assessed as Unfavourable-Inadequate. Area loss was recorded for 1330, mostly in the form of infilling/reclamation for a range of uses, while Structure and functions has primarily been negatively impacted by livestock grazing, most commonly cattle - an impact that is likely to continue into the future. The Overall conservation assessment for 1410 was Unfavourable-Inadequate. While Structure and functions of 1410 was assessed as Favourable, Area was assessed as Unfavourable-Inadequate due to habitat loss attributable mainly to infilling/reclamation. Losses in area are expected to continue into the future. For 1420, the Overall conservation assessment was Unfavourable-Bad. This was due to an Area assessment of Unfavourable-Bad, with area loss caused by smothering of the habitat under algal mats whose growth has been promoted by the eutrophication of the associated waterbody. Structure and functions was assessed as Unfavourable-Inadequate due to the spread of Spartina anglica at one site and the complete loss of the habitat at another. The report concludes with a discussion of the results for each of the target Annex I habitats and recommendations for conservation actions required to improve the status of saltmarsh habitats in Ireland. The conservation actions focus on the potential for control of the alien invasive species Spartina anglica, the implementation of agri-environment schemes, and managed realignment as a tool to combat some of the impacts of sea-level rise. Recommendations are also made for the refinement of the survey and assessment methodology and for areas of future research.

Site list: 000101, 000190, 000197, 000268, 000335, 000343, 000458, 000622, 000627, 000697, 000781, 001040, 001090, 001141, 001482, 001957, 002012, 002070, 002111, 002137, 002158, 002162, 002165, 002170, 002249, 002287

The NPWS Project Officer for this report was: Deirdre Lynn; Deirdre.Lynn@chg.gov.ie This IWM was edited by Deirdre Lynn & Aoife Delaney