In 1909-11 Robert Lloyd Praeger brought a team of 100 scientific specialists from all over Europe to map the flora, fauna, geology and archaeology of Clare Island, a small, exposed Atlantic island off the west coast. The gathering led to the publication of the path-breaking 'Clare Island Survey'. A century later the survey was repeated as the 'New Survey of Clare Island' (1992-2009) and both works were published extensively by the Royal Irish Academy. This third volume in the series examines the intertidal marine ecology of Clare Island. The shores of Clare Island are as exposed as any in Europe and are important baseline sites for the assessment of future environmental change. A knowledge of the ecology of the key organisms of these exposed shores is of fundamental importance, which the contributors bring to this volume after 100 years of change.