A Water Framework Directive saltmarsh assessment tool was recently developed through the Environmental Protection Agency (EPA)-funded SMAATIE (Saltmarsh Angiosperm Assessment Tool for Ireland) project. This new publication addresses knowledge gaps identified by the SMAATIE project that limited the development and application of the tool, and provides an additional, synergistic understanding of saltmarsh processes.
In terms of vegetation assessment of saltmarshes, three related rarity indices were developed and applied at ecosystem, habitat and community levels. Saltmarshes were categorised as “specialist vascular plant habitats”, whose biodiversity value lies in the occurrence of specialist salt-tolerant species rather than high species richness. The integration of rarity indices into site conservation assessments is recommended. A major change in the categorisation of vegetation communities and associated mapping of Irish saltmarshes was switching to the Irish Vegetation Classification (IVC) system. The IVC based maps were more detailed and informative than those previously produced.
The report also explores the need for ‘managed realignment’; the deliberate process of altering flood defences to allow flooding of a presently defended area, associated with predicted sea-level rise. Without managed realignment, which allows saltmarshes to migrate inland as a response to sea level rise, saltmarshes were predicted to decline at the case study sites in a majority of simulations. ‘Ireland is lagging behind other European countries in the adoption of managed realignment as part of a sustainable coastal management strategy’.