Cold water corals
Lophelia pertusa
© A. Freiwald
Hard corals are precious and protected species. Strict provisions exist for their import or export under CITES, the Convention regulating trade in endangered wild animal and plant species and their products, and even trade as souvenirs requires legal permits.
Related to sea anemones, each coral polyp has a ring of tentacles surrounding a single body opening. The polyp, a small columnar body, produces a hard calcium carbonate skeleton and retracts the tentacles into its skeleton for protection. Lophelia is found far beyond the reach of sunlight - unlike its tropical cousins - unusually at depths of 200-400m.
Perfectly adapted to the dark environment, the polyps do not contain algae providing them with carbohydrates, but rely on catching passing food in the water column. With their tentacles they get hold of small crustaceans and other zooplankton.
Its colonies tend to be found in areas where there are strong water currents - on rocky ledges or in narrow regions of some Norwegian fjords, for example. These currents supply food and remove sediments that would otherwise smother the coral polyps.
Lophelia can accumulate to form vast banks, or biotherms, and coral reefs. Sula Ridge is an example, a submarine structure in about 300m of water in the Norwegian Sea. It was recently surveyed and the reef on top found to be over 13 km in length, rising to over 35 m above the seabed.
Reefs provide a habitat for many species - diversity can be as rich as in the tropics. The number of starfish, urchins, brittle stars and mats is very similar to that found on shallow water tropical reefs.
Since March 1999, the Norwegian government has prohibited 'all intentional destruction of coral reefs' in its waters and additionally banned 'all use of fishing gears that are dragged and may get in contact with the sea floor' in the Sula Reef area.
