Distribution, abundance and size of Lophelia pertusa coral reefs in mid-Norway in relation to seabed characteristics

• Published in: Journal of the Marine Biological Association of the United Kingdom
• Main Authors: Mortensen, Pål B., Hovland, T., Fosså, Jan Helge, Furevik, Dag M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2001
• Subjects: Halten; Norway; Lophelia pertusa
• Online Access: http://dx.doi.org/10.1017/s002531540100426x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002531540100426X

This paper presents results on the distribution, abundance, and size of Lophelia pertusa coral reefs in mid-Norway (62°30&;–65°30&;N) as compiled from own investigations, earlier scientific reports, reports from fishery surveys and fishermen. Detailed bathymetrical mapping covering an area of ∼600 km 2 along the Halten gas-pipeline, and two nearby areas across the shelf revealed 70 Lophelia reefs. In general, the reefs occurred close to breaks and escarpments. High densities of up to nine reefs per km 2 were found in areas with a rugged seabed topography and with a slope >0·6°. These seabed features have probably positive influence on the transport and concentration of food particles and thus control the local distribution of Lophelia . The area covered by individual reefs varied between 1230 m 2 and 37,310 m 2 with a mean of 5628 m 2 . The height of the reefs was positively correlated with the area. Reefs <10,000 m 2 had a circular outline, while larger reefs were elongate, aligned parallel to the depth contours. Along the pipeline the average density of Lophelia reefs was 0·09 km −2 which indicates that the total number of reefs is ∼6300, covering ∼35 km 2 within the whole study area.