Citation: Cotton, A.D. 1912 Clare Island Survey: Marine algae. Proceedings of the Royal Irish Academy 31B: 1-178
Number of Pages: 178
Volume Part: 15
Keywords: Alga, Checklist, Clare Island, Community, Flora, History, Littoral, Marine, Mayo, Rock, Seaweed, Sublittoral, Taxonomy
Abstract: This report states that it provides the first detailed account of the algal associations in any areas of the British Isles. Descriptions take account of the work of Kjellman and Borgesen and are described by formation and association. The five formations are (1) rocky shore, (2) sand and sandy mud, (3) saltmarsh, (4) river mouths, and (5) brackish bays. The first three are described for Clare Island. On exposed coasts, littoral areas have the following associations: Hildenbrandia-Verrucaria, Prasiola, Entermorpha intestinalis, Fucaceae, Lichina, Porphyra, Bangio-Urospora-Ulothrix, Rhodymenia, Laurencia-Gigartina, Callithamnion arbuscula, Nemalion, Himanthalia, Corallina-Lithothamnium, pool vegetation, cave vegetation. On sheltered coasts, littoral areas have the following associations: Hildenbrandia-Verrucaria, Fucaceae, Lichina, Porphyra, Laurencia-Gigartina, Corallina-Lithothamnium, Corallina-Cladostephus, Rhodochorton-Floridulum, sand pool vegetation, and cave vegetation. The associations are described together with limited descriptions of sublittoral associations: Laminaria and encrusting algae associations are described for exposed and sheltered sublittoral habitats, as well as the Fruticulose Lithothamnion association for sheltered sublittoral. Other associations described are those of Zostera, pebbles in quiet bays, and tidal channels of brackish bays. A systematic list of marine algae found is given, and a comparison with other geographical areas discussed. Ninety-two species and eleven varieties are new to the Irish flora, of which three species and two varieties are new to science: Calothrix endophytica, Ascocyclus saccharinae, Ptilothamnion lucifugum, Codium mucronatum var. atlanticum and Fucus vesiculosus var. muscoides.