Darwin Mounds describes a vast field of undersea sand mounds situated off the north west coast of Scotland, first discovered in May 1998, they provide a unique habitat for ancient
deep water coralThe habitat of deep water corals, also known as cold water corals, extends to deeper, darker parts of the oceans than tropical corals, ranging from near the surface to the abyss, beyond where water temperatures may be as cold as 4° C...
reefs. Found using remote sensing techniques, during surveys funded by the oil industry and steered by the joint industry and United Kingdom government group the Atlantic Frontier Environment Network (AFEN) (Masson and Jacobs 1998).
Darwin Mounds describes a vast field of undersea sand mounds situated off the north west coast of Scotland, first discovered in May 1998, they provide a unique habitat for ancient
deep water coralThe habitat of deep water corals, also known as cold water corals, extends to deeper, darker parts of the oceans than tropical corals, ranging from near the surface to the abyss, beyond where water temperatures may be as cold as 4° C...
reefs. Found using remote sensing techniques, during surveys funded by the oil industry and steered by the joint industry and United Kingdom government group the Atlantic Frontier Environment Network (AFEN) (Masson and Jacobs 1998). The mounds were named after the
research vesselA research vessel is a ship designed and equipped to carry out research at sea. Research vessels carry out a number of roles. Some of these roles can be combined into a single vessel, others require a dedicated vessel....
, itself named for the eminent naturalist and
evolutionIn biology, evolution is change in the genetic material of a population of organisms from one generation to the next. Though changes produced in any one generation are normally small, differences accumulate with each generation and can, over time, cause substantial changes in the population, a...
ary theorist
Charles DarwinCharles Robert Darwin FRS was an English naturalist who realised and presented compelling evidence that all species of life have evolved over time from common ancestors, through the process he called natural selection...
.
Located some 1,000 m below the surface of the North Atlantic ocean, approximately north-west of
Cape WrathCape Wrath is a cape in Sutherland, Highland, in northern Scotland. It is the most northwesterly point on the island of Great Britain....
, the north-west tip of mainland Scotland. There are hundreds of mounds in the field, which in total cover approximately 100 km². Individual mounds are typically circular, up to 5 m high and 100 m wide. Most of the mounds are also distinguished by the presence of an additional feature referred to as a 'tail'. The tails are of a variable extent and may merge with others, but are generally a teardrop shape and are orientated south-west of the mound. The mound-tail feature of the Darwin Mounds is apparently unique globally.
The mounds are comprised mostly of sand, currently interpreted as '
sand volcanoA sand volcano or sand blow is a cone of sand formed by the ejection of sand onto a surface from a central point. The sand builds up as a cone with slopes at the sand's angle of repose. A crater is commonly seen at the summit...
es'. These features are caused when fluidised sand 'de-waters' and the fluid bubbles up through the sand, pushing the sediment up into a cone shape. Sand volcanoes are common in the
DevonianThe Devonian is a geologic period and system of the Paleozoic era spanning from . It is named after Devon, England, where rocks from this period were first studied....
fossil record in UK, and in seismically active areas of the planet. In this case, tectonic activity is unlikely; some form of
slumpSlump is a form of mass wasting event that occurs when loosely consolidated materials or rock layers move a short distance down a slope. The landmass and the surface it slumps upon is called a failure surface...
ing on the south-west side of the undersea (Wyville-Thomson) Ridge being a more likely cause. The tops of the mounds have living stands of Lophelia and blocky rubble (interpreted as coral debris). The mounds provide one of the largest known northerly cold-water habitats for
coralCorals are marine organisms from the class Anthozoa and exist as small sea anemone-like polyps, typically in colonies of many identical individuals...
species. The mounds are also unusual in that
Lophelia pertusaLophelia pertusa is a species of cold-water coral which grows in the deep waters throughout the North Atlantic ocean. L. pertusa reefs are home to a diverse community, however the species is extremely slow growing and may be harmed by destructive fishing practices, or oil exploration and...
, a cold water coral, appears to be growing on sand rather than a hard substratum. Prior to research on the mounds in 2000, it was thought that Lophelia required a hard substratum for attachment.
The deep-water coral systems located upon the mounds, are especially fragile. Unlike shallow-water
coral reefCoral reefs are aragonite structures produced by living organisms, found in marine waters containing few nutrients. In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an exoskeleton of calcium carbonate...
s, they are not adapted to cope with minor disturbances such as wave action.
The mounds also support significant populations of the
xenophyophoreXenophyophores are marine protozoans, giant single-celled organisms found throughout the world's oceans, but in their greatest numbers on the abyssal plains of the deep ocean. They were first described as sponges in 1889, then as testate amoeboids, and later as their own phylum of Protista. A...
Syringammina fragilissima. This is a giant single-celled organism (a protozoan) that is widespread in deep waters, but occurs in particularly high densities on the mounds and the tails. Individual xenophyophores can grow to be larger than 20 cm and are often very fragile. The corals themselves provide a habitat for a wide diversity of other marine life including sponges,
wormThe term worm is used to describe many different distantly-related animals which have a long cylindrical body and no legs.Most animals called "worms" are invertebrates, but the term is also used for the amphibian caecilians and the slow worm Anguis, a legless burrowing lizard...
s,
crustaceanCrustaceans are a very large group of arthropods, comprising almost 52,000 described species , and are usually treated as a subphylum . They include various familiar animals, such as crabs, lobsters, crayfish, shrimp, krill and barnacles...
s and molluscs. Among these starfish,
sea urchinSea urchins or urchins are small, spiny, globular animals that compose part of class Echinoidea. They are found in oceans all over the world. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple,...
s and
crabCrabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax.Crabs have a soft body covered with a hard shell. They are generally covered with a thick exoskeleton, and armed with a...
s. Various fish have been observed, including blue ling, roundnose grenadier, and the
orange roughyThe orange roughy, red roughy, or deep sea perch, Hoplostethus atlanticus, is a relatively large deep-sea fish belonging to the slimehead family . The Marine Conservation Society has categorized orange roughy as vulnerable to exploitation...
.
On 23 October 2001, UK Minister
Margaret BeckettMargaret Mary Beckett is a British Labour politician, who has been the Member of Parliament for Derby South since 1983, rising to become the Deputy Leader of the Labour Party under John Smith, from 18 July 1992 to 12 May 1994, and subsequently the Acting Leader of the Party following John Smith's...
made a commitment at
WWF'sThe World Wide Fund for Nature is an international non-governmental organization working on issues regarding the conservation, research and restoration of the environment, formerly named the World Wildlife Fund, which remains its official name in the United States and Canada...
Oceans Recovery Summit in
EdinburghEdinburgh is the capital city of Scotland. It is the second largest Scottish city, after Glasgow, and the seventh-most populous in the United Kingdom. The City of Edinburgh Council is one of Scotland's 32 local government council areas....
to protect the Darwin Mounds. The summit launched the Edinburgh Declaration, targeting politicians and marine stakeholders alike to sign up to action to safeguard the seas. Deep water
bottom trawlingBottom trawling is trawling along the sea floor.The scientific community divides bottom trawling into benthic trawling and demersal trawling...
had been occurring in the area, with nets as heavy as one tonne dragged across the sea floor. Researcher Jason Hall-Spencer of the University of Glasgow had found pieces of coral at least 4,500 years old in the nets of trawlers operating off the coast of Ireland and Scotland. Pieces of coral up to one meter square were found in the nets of French trawling vessels that had been scraping the seabed one kilometer down. It is known that much coral was destroyed by these nets and the mounds themselves in some areas were found to be scrapped and flattened. The mounds are ancient structures and this damage is permanent.
Post the discovery of the mounds three well documented surveys of the area were undertaken one in June 1998 (Bett 1999), August 1999 (Bett & Jacobs 2000) and twice during summer 2000 (B. Bett, pers. comm.). Instruments deployed during the studies have included
side-scan sonarSide-scan sonar is a category of sonar system that is used to efficiently create an image of large areas of the sea floor...
, stills and video cameras and piston corers. However, we will never know the entirety of what was lost during the period of time when the heavy netted fishing trawlers were operating above the mounds. On 22 March 2004 EU Fisheries Ministers in Brussels finally agreed to give permanent protection to Scotland's unique cold-water coral reefs, recognising the Darwin Mounds as an important habitat. As of 2004 deep-water bottom trawling in the area has been made illegal.
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