Lophelia Coral | Oceana Canada

Corals & Other Invertebrates

Lophelia Coral

Lophelia pertusa

Also known as

Spider hazards, white stony coral, eye coral

Distribution

Tropical to sub-polar latitudes in the north Atlantic

Ecosystem/Habitat

Deep-sea on hard substrates

Feeding Habits

Filter feeder

Conservation Status

Not listed

Taxonomy

Order Scleractinia (hard corals); Family Caryophylliidae (true stony corals)

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The lophelia coral is a true stony coral that lives in the deep sea in cold, temperate waters rather than on shallow, tropical coral reefs. Unlike shallow-water corals, lophelia corals and other deep-water corals do not get their food from symbiotic algae living inside their cells. Instead, they obtain all of their energy by eating plankton and other organic matter from the water that flows along deep-sea currents. Like all corals, lophelia are closely related to anemones and jellyfishes.  Lophelia coral are one of the most abundant and widely distributed deep-sea corals in the Atlantic  and provide important habitat for many marine species, including fish, crustaceans and even other species of coral.

Lophelia coral is an important deep-sea, reef-forming coral and can be incredibly long-lived. They are a bushy, branching coral whose branches grow out and fuse together, forming reefs. The polyp, or adult stage of the lophelia coral, is a translucent yellow, pink or white colour. Each polyp has up to 16 tentacles that are used to feed on plankton and other organic matter. Individual polyps are connected by their skeletons which are made up of calcium carbonate that they extract from the surrounding sea water. In turn, each coral reef  is made up of hundreds of thousands of individual polyps that live together as a colony. Wherever they live, lophelia corals build structure that provides nursery, refuge, feeding and habitat for many kinds of marine wildlife, like fish, crustaceans and other invertebrates. 

As the coral reef grows, the corals continue to grow on top of each other with dead coral skeletons forming the centre of the reef. Therefore, the size of a lophelia coral colony or reef is related to the age of the reef. The largest known intact lophelia reef can be found off the coast of Norway and measures 40 kilometres long by three kilometres wide. Lophelia coral reefs of this size may be tens of thousands of years old.

Individual lophelia coral polyps are either male or female, which means they are dioecious. While not much is known about the breeding behaviour of this species, it is known that in the winter months polyps will release eggs and sperm into the water to be fertilized. One individual polyp can release approximately 3,000 eggs a year. Lophelia corals are also able to reproduce asexually through fragmentation or budding. While individual polyps are not thought to live for more than 20 years, a lophelia coral reef can be hundreds or thousands of years old as new coral grows on top of the skeletons of older corals.

This species is commonly found at depths of approximately 200 to 1,000 metres, but it has been observed or collected from depths of nearly 3,000 metres .  Lophelia corals are also frequently found in areas with fast moving currents which carry nutrients and plankton that they filter feed on. Most of the lophelia corals in Canada are found along the edge of the Scotian Shelf, in the Atlantic Ocean, on steep embankments with fast moving currents.

Although lophelia corals are not directly targeted by any fishing industry, damage to corals and reefs caused by fishing practices is well documented, most notably from bottom trawling. This practice of dragging large, heavy fishing nets along the seafloor destroys deep-sea coral reefs by scraping and smashing the corals, often reducing them to rubble. By flattening these important corals that so many other species rely on, the deep sea ocean ecosystem loses important habitats. For an extremely slow growing species like the lophelia coral, destruction of even a small area of reef, by a single boat, may require hundreds to thousands of years to recover – if ever. Given the amount of bottom trawling that occurs throughout this species’ range, it is likely at risk of endangerment.

The status of lophelia coral is not well understood in Canada nor throughout the rest of its range. In 1997, Fisheries and Oceans Canada (DFO) began conducting video surveys in prime coral habitats in Atlantic Canada, but it was not until 2003 that the first observation of live lophelia coral was made . The single known lophelia coral reef in Canada is found along the edge of the Scotian Shelf, however there are other small groups of lophelia coral that are surrounded by large tracts of coral skeleton rubble caused by destructive fishing practices. The Stone Fence Lophelia Coral Conservation Area was established in 2004 by DFO southeast of Cape Breton, Nova Scotia, closing the lophelia coral reef to all bottom fishing activities in order to protect the reef and allow for recovery. 

Lophelia corals are also at risk from ocean acidification caused by climate change. As the ocean absorbs carbon dioxide from the atmosphere, it becomes increasingly acidic – a phenomenon that also results in decreased calcium carbonate in the ocean. Since lophelia corals rely on calcium carbonate to build their skeletons, they cannot survive or grow without it. The deep waters that lophelia corals call home are also naturally more acidic than shallow waters, so they are particularly vulnerable to this problem. Unless carbon dioxide emissions are reduced, scientists predict the waters in which deep-water corals live may eventually become acidic enough to literally dissolve their skeletons. Acidification not only risks the survival of this and other corals but also the high numbers of other species that rely on coral reefs.

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