Ecological effects of Spartina anglica on the macro-invertebrate infauna of the mud flats at Bull Island, Dublin Bay, Ireland

Abstract. Spartina anglica (C. E. Hubbard) is a relatively new invasive perennial grass species in Ireland. It is well adapted to the intertidal mudflat environment and forms mono-specific swards. There have been concerns about its potential to impact negatively the ecosystems of mud flats and salt marshes.

This ongoing project investigates the ecological effects of S. anglica, and its control, on the mudflats and saltmarsh at Bull Island, and the implications for management of S. anglica. The diversity and density of the macro-invertebrate infauna and some physical factors of the sediment were compared in: a) clumps of S. anglica, b) areas vegetated by Salicornia spp., c) an adjacent area of bare mud, and d) an unvegetated area. Presence of S. anglica had a significant effect on the density and diversity of macro-invertebrate infauna species. The results suggest that clumps of S. anglica can provide a habitat that supports a macro-invertebrate infauna as abundant and species rich as areas vegetated by Salicornia spp.