Case Study - The Lophelia Reefs of Norway

Introduction > Images > Videos > References

Norway has the highest known density of Lophelia pertusa reefs in the world, mapped at depths between 39 and 400 metres. The estimated spatial coverage of Norwegian Lophelia reefs is 2,000 km², a greater coverage than some countries with well known tropical reefs such as Belize, Mozambique or Seychelles. Some of these reefs have been estimated at over 8,000 years old based on geophysical, visual, geochemical, radiocarbon and other analyses. The first Lophelia reef ever photographed under water (right) was off the coast of northern Norway at 120 m water depth, in 1982, during pipeline route surveys conducted by the petroleum company Statoil. Subsequently, they were found also on the continental shelf off Mid-Norway in 1985 and onwards.

Here, acoustic surveys revealed large mounds, which were 10 to 25 m in height. It wasn't until 1990, that the research team were able to inspect these mounds using a remotely operated vehicle - the first use of an ROV to record Lophelia reefs using colour video. Innovations also included specially designed buckets (left) to collect samples of Lophelia from the sea-floor some 280 - 300 metres down. From that point onwards research into the Norwegian Lophelia reefs has been intensive, with several hundred reefs discovered to date.

The authors thank Dr. Martin Hovland (Statoil) for contributing the amazing videos and imagery of Norwegian Lophelia reefs.