![]() Photo: Asgeir Alvestad Redfish and common ling caught in 300 metres of water from the Heidrun platform. Redfish and cusk caught in 300 metres of water from the Heidrun platform. L pertusa also thrives along steep cliffs in the fjords. Generally speaking, reefs flourish on sites a little higher than the general sea bottom – on ridges, for example, the edges of fishing banks, atop iceberg ploughmarks or on fjord thresholds. More or less circular reefs stand apart, with living colonies atop a zone of crushed coral on the surrounding seabed. None of the reefs are entirely similar in shape or size, and vary from tear-shaped to long banks. The complex grows on long ridges raised high above the surrounding seabed.Ī reef complex comprises hundreds or thousands of corals which are so closely packed that they have combined into great continuous units.Ĭurrents in the areas of reef growth can vary and flow from various directions, which provides good growth conditions on all sides. Located in 280-300 metres of water, this reef is 13 kilometres long, up to 35 metres high and 700 metres wide. This area contains the world’s largest coldwater coral bank in deep seas. The Sula Ridge is special in that countless small reefs have coalesced into continuous structures of unique size. ![]() Some reefs grow along the outer margin of the continental shelf, while others are found on the shelf itself and in the fjords. Some large coral banks discovered there are estimated to be around 7 000 years old. The seas off mid-Norway contain the largest number and greatest density of reefs. This has since been introduced by the Ministry of Fisheries. Report from the Norwegian Institute of Marine Research no 8. Fotnote: Jan Helge Fosså, Tina Kutti, Pål Buhl Mortensen and Hein Rune Skjoldal (2015): Vurdering av norske korallrev. Ī number of new reefs have been identified in recent years, and the Norwegian Institute of Marine Research found in 2015 that they needed special protection. When it became known in the 1990s that some of these communities had been damaged by bottom trawling, such fishing was banned in the most vulnerable zones from the winter of 1992. All coral reefs off Norway are now covered by a general conservation order which prohibits any harm to them. Since Norway’s corals account for 30 per cent of the global total of L pertusa, its seas are regarded as a core area for this species. The flow of Atlantic water is particularly important for growth. ![]() This grow along most of the Norwegian coast, apart from its southern end, Sogn og Fjordane county and the northernmost part of Finnmark county.Ĭurrents and environmental factors are the most likely reasons for the absence of reefs along these sections of the coast. ![]() Ĭoral reefs off Norway are built by the coldwater coral Lophelia pertusa. Reefs will not form off the mouths of big rivers such as the Amazon, for example, because of all the particles carried in their water from erosion of the hinterland. Photosynthesising algae which live inside the polyp cells need sunlight to function, which is why most corals are found in clear shallow water. Photographing or filming them usually requires special equipment mounted on a remotely operated vehicle (ROV).Īs a result, it is only in recent years that knowledge of these coldwater coral communities has become more detailed.Ĭoral reefs are built up from calcareous “skeletons” formed by tiny polyps living in colonies. They can also be colourful and beautiful, and serve as centres of diversity for marine species. The banks found off Norway grow in colder seas with plenty of current in 100-500 metres of water. Tropical reefs are found in shallow seas with clear water and good light conditions – perfect for observation by diving or snorkelling.
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