Coral reefs in Norway
Lophelia pertusa

Distribution of coral reefs

In recent years there has been a renewed interest in research on cold-water corals resulting in a much better understanding of the distribution and the size of the coral reefs. In Norway information has been collated from many sources, e.g. literature, fishermen, the Norwegian Directorate of Fisheries, oil companies and our own investigations.

Lophelia is distributed along the whole coast of Norway from the Tisler reef in Skagerrak close to the Swedish border in the south, to the east of Finnmark county in the north. The species is found in most fjords, on the continental shelf and along the shelf break mostly at 200-400 m depth. The highest densities and largest continuous reefs occur along the continental break and on edges of shelf-crossing trenches and morainic formations.

In a wider perspective Lophelia is distributed throughout the world oceans except in the polar regions. The preferred temperature range seems to be 6-8 °C and the main depth distribution between 200 and 1000 m. The shallowest record of a living Lophelia reef is at 39 m in Trondheimsfjorden, Norway, while the deepest down to 3000 m in the Atlantic.

Seven species of scleractinian species occur in Norwegian waters of which Lophelia pertusa and Madrepora oculata (L., 1758) form colonies. Madrepora, however, is less abundant than Lophelia and has never been reported to build reefs. Lophelia has been known for centuries to scientists and fishermen, especially those using passive gear in deep water such as gillnets and longlines. The first systematic study on the distribution of Lophelia and the associated fauna in Norway was performed by Dons (1944).

IMR perform annual cruises to map corals and assess the condition of the reefs.