Coral reefs in Norway
Lophelia pertusa

The discovery of Lophelia pertusa reefs in Norwegian waters

The discovery of large Lophelia pertusa coral reefs on deep water in the northeast Atlantic as late as the mid-eighties, is astonishing since the species was described and depicted by Linné and Gunnerus already in the 18th century (Linné 1758, Gunnerus 1768). Although research on corals has been carried out since Linné’s description, it was only recently that the technological development allowed for an extensive visual investigation of the deep sea.

After the work by Gunnerus many Norwegian zoologists investigated the reefs, e.g. M. Sars and G.O. Sars, just to mention two of the most acknowledged scientists. Also Johan Hjort knew the reefs well and in the book The Depths of the Ocean (Murray and Hjort 1912) he ascribed “The presence of corals like the Lophohelia over great parts of the slope of the Norwegian Sea...” to be the “...most interesting indication of the motion of the organic matter along the sea-bottom”. This is a very interesting statement inferring that Lophelia relies on food supplied by currents and thus prefers to live in an advective environment.

For a long time Lophelia was only known from the coasts of Norway, but was highly prized by zoologists also outside the country due to the very rich and interesting reef fauna. The fishermen, on the other hand, showed a dual attitude towards the Lophelia reefs; they appreciated the reefs as good fishing places, but hated them because of the loss of fishing gear entangled in the corals.

It was not until Dons issued his review in 1944 that we got an overview of the wide distribution of Lophelia where about 100 reef sites are listed in Norway including some sub-fossil records. In 1960 Burdon-Jones and Tambs-Lyche presented a list with 300 different species from the Brattholmen reef near the city of Bergen.

A new burst of interest in deep-water reefs came with the oil exploration on the continental shelf in the 1980ties. The oil companies surveyed the sea bottom with large ROVs and documented Lophelia reefs with colour video, and for the first time it became possible to see the impressive formations and colourful animal life on the reefs. Documentation of reefs damaged by the trawling fleet in the 1990ties initiated a mapping and reef assessment program by the Institute of Marine Research. This is an on-going program thanks to which many new, large reefs have been reported. Information on the recent investigations on the biology, ecology and distribution of the reefs in Norwegian waters can be found in e.g. Hovland and Mortensen (1999), Mortensen (2000), Fosså et al. (2000, 2002), and Freiwald (2002).

References

Burdon-Jones, C. & H. Tambs-Lyche 1960. Observations on the fauna of the North Brattholmen stone-coral reef near Bergen. - Årbok for Universitetet i Bergen, Matematisk-naturvitenskaplig Serie. 1960 (4):1-24.

Dons, C. 1944. Norges korallrev. - Det Kongelige Norske Videnskabers Selskabs Forhandlinger 16:37-82.

Gunnerus, J.C. 1768. Om nogle norske coraller. - Det Kongelige Norske Videnskabers Selskabs Skrifter 4:38-73.

Fosså, J.H., P.B. Mortensen og D.M. Furevik 2000. Lophelia korallrev langs norskekysten. Forekomst og tilstand. – Fisken og havet nr. 2, 2000. 94 pp.

Fosså, J.H., P.B. Mortensen and D.M. Furevik 2002. The deep-water coral Lophelia pertusa in Norwegian waters; distribution and fishery impacts. Hydrobiologia 417:1-12.

Freiwald, A., V.Hühnerbach, B. Linberg, J.B. Wilson, L. Cambell and J. Campbell 2002. The Sula reef complex, Norwegian shelf. – Facies 47:179-200.

Hovland, M., og P. B. Mortensen 1999. Norske korallrev og prosesser i havbunnen. - John Grieg forlag, Bergen 155 pp.

Linné, C. von 1758. Systema naturae per Regna tria naturae, secundum classes, ordines, genera, species. TomusI. Regnum animale. 10. Edition. Stockholm. 824 pp.

Mortensen, P.B. 2000. Lophelia pertusa (Scleractinia) in Norwegian waters. Distribution, growth, and associated fauna. - Dr. scient. Thesis, Department of Fisheries and Marine Biology, University of Bergen, Norway.

Murray, J. and J. Hjort 1912. The Depths of the Ocean. 821 pp. Macmillan, London.