|Species diversity and spatial distribution of invertebrates on deep-water Lophelia reefs in Norway|
|Mortensen, P.B.; Fosså, J.H. (2006). Species diversity and spatial distribution of invertebrates on deep-water Lophelia reefs in Norway, in: Suzuki, Y. et al. (Ed.) (2006). Proceedings of the 10th International Coral Reef Symposium, Okinawa, June 28 - July 2, 2004. pp. 1849-1860|
|In: Suzuki, Y. et al. (Ed.) (2006). Proceedings of the 10th International Coral Reef Symposium, Okinawa, June 28 - July 2, 2004. Japanese Coral Reef Society: Tokyo, more|
Diversity and spatial distribution of invertebrates were studied on four inshore and four offshore Lophelia pertusa-reefs in Norway using ROV (Remotely Operated Vehicle), dredge, and grab. A total of 361 species was identified. Mollusca, Arthropoda and Bryozoa were the most species rich phyla contributing 48% to the total number of species. The species diversity (H’) was highest in samples with a low proportion (1- 20%) of live coral, and lowest for samples from the coral rubble zone surrounding the reefs. The number of individuals was highest in samples with a high proportion (> 20%) of live coral. Deposit feeders were most common in the rubble, whereas suspension feeders dominated among live coral. Most higher taxa were represented by more species on the inshore compared to the offshore reefs. This was most evident for Cnidaria, Crustacea, Polychaeta and Tunicata, whereas Foraminifera were more species rich offshore. Our results were compared with those of three earlier studies in the Northeast Atlantic. A total of 769 species have been recorded, but only 21 were common for all four studies. The cumulative number of species with increasing number of investigations indicates that far more species occur on Lophelia-reefs than recorded so far. The results from sampling with different gears were compared. To describe the spatial distribution of invertebrates within a Lophelia-reef, and to increase the sampling precision, we recommend using a grab equipped with a video camera because it samples the fauna more representatively and damages less coral compared to a dredge.