Contributions to Zoology, 76 (2) 121-142 (2007) Sponge diversity and community composition in Irish bathyal coral reefs Rob W.M. van Soest1, Daniel F.R. Cleary1,2, Mario J. de Kluijver1, Marc S.S. Lavaleye3, Connie Maier3, Fleur C. van Duyl3 1Zoological Museum of the University of Amsterdam, P.O. Box 94766, 1090 GT Amsterdam, the Netherlands, soest@ science.uva.nl; 2Institute for Biodiversity and Ecosystem Dynamics, Faculty of Science, University of Amsterdam, P.O. Box 94766, 1090 GT, Amsterdam, the Netherlands,
[email protected]; 3Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, the Netherlands,
[email protected] Key words: coldwater, multivariate analysis, North Atlantic, ordination, PCA, Porifera, RDA Abstract west of Ireland were found to have a combined sponge species richness of 191 species, exceeding the richness of individual reef Sponge diversity and community composition in bathyal cold mound areas by c. 38-45%. Sponge presence in CWRs is water coral reefs (CWRs) were examined at 500-900 m depth clearly structured and controlled by biotic and abiotic factors. on the southeastern slopes of Rockall Bank and the northwestern In particular, live coral presence appears a signifi cant predictor slope of Porcupine Bank, to the west of Ireland in 2004 and 2005 of CWR sponge composition and diversity. with boxcores. A total of 104 boxcore samples, supplemented with 10 trawl/dredge attempts, were analyzed for the presence and abundance of sponges, using microscopical examination of Contents (sub)samples of collected coral branches, and semi-quantitative macroscopic examination. Approximate minimum size of iden- Introduction ...................................................................................