Citation: Keegan, B.F. 1974 The macrofauna of maerl substrates on the west coast of Ireland. Cahiers de Biologie Marine 15: 513-530
Number of Pages: 18
Keywords: Alga, Community, Echinodermata, Fauna, Flora, Littoral, Maerl, Marine, Seaweed, Sublittoral
Abstract: The macrofauna of maerl (Lithothamnion corallinoides) in Kilkerrin Bay and Galway Bay was sampled using a combination of techniques (including diving), with anchor dredges especially effective. Six maerl or predominantly maerl substrata are described and species listed. Littoral maerl debris is 'strikingly barren' whilst, in contrast, the subsurface epifauna of arbisular deposits is 'spectacular' and includes dense aggregations of Paracentrotus lividus (> 1,600 per sq m surface area), plus ophiuroids, decapods and bivalves. Living maerl in the sublittoral includes many epifaunal organisms. On maerl/soft ground, the fauna is limited but still very rich. This substratum was specifically studied in detail and quantitative records are provided together with an indicator of the maximum burrowing depth of some species. 'Maerl/hard ground' has a restricted epifauna dominated by Antedon bifida and Ophiocomina nigra. 'Maerl debris - unstable' has a predominantly poor and not especially diagnostic fauna. The sixth grouping is 'composite of maerl and muddy sand'.