Darwin Mounds
Hundreds of deep-water sand volcanoes off Scotland
© Erling Svensen
Although coral reefs are normally associated with the tropics, they exist in cold water too. The Darwin Mounds, a deep-lying reef north of Scotland, is an example, but it's in danger of disappearing through overfishing.
Discovered only in 1998, the Darwin Mounds is a collection of hundreds of deep-water sand volcanoes off Scotland, on which abundant quantities of coral have grown, supporting a rich diversity of marine life.
Up to 5 m high and 100 m across
The mounds are huge, spreading across at least 100 km². They are an average 5 m high and lie a thousand metres deep. There are hundreds of individual mounds that are typically circular in outline and up to 5 m high and 100 m across. About 185 km north west of Cape Wrath, they are within the United Kingdom's 200 nautical mile offshore waters. Their protection is therefore the responsibility of the UK government.
The most important coral reef discovery
The Darwin Mounds are one of 90 coral reefs to be discovered in the North-East Atlantic, but are by far the most important to date. They are also endangered, having been seriously damaged by deep-sea fishing.
The reef is covered with the cold-water coral Lophelia pertusa, a species that has also been recorded in the Mediterranean Sea, along the east coast of North America, Brazil, West Africa and the Mid-Atlantic Ridge. Its skeletons are thousands of years old. The Darwin Mounds are still poorly researched, but it is clear from other North-East Atlantic coral reefs that they support up to 300 different wildlife species.
Vital support for the fish population
The mounds have unique tails, up to several hundred metres in length, which contain a high population of giant protozoans called xenophyophores, important foodstuff for deep-sea fish. The reef is also a vital focus for fish reproductive cycles.
Supporting many marine species
There can be hundreds of corals on any one mound, maintaining an animal life that differs substantially from the surrounding seabed. Cut-throat eel, round-nosed grenadier, sponges and starfish, sea urchins, hermit crabs and worms are among the creatures dependent on the reef for life.
