Natural England - Coral gardens

Coral gardens

When we think of corals, we think of shallow, warm tropical seas, not the cold, dark oceans around Britain. However, in varying depths of water – from 30m to several thousand metres deep on underwater mountains – there are beautiful coral gardens. They are made up of dense aggregations of colonies of one or more coral species. In some locations, there may be up to 700 colonies in an area of one hundred square metres.

Coral gardens © JNCC

Coral gardens © JNCC

Coral gardens occur in water temperatures of between 3 and 8ºC, and can be found on different types of seabed. Some corals need a hard surface to attach to when they first begin to grow from larvae, while others, such as sea pens are found in muddy areas.

Coral gardens provide a home for many other animals – there is not enough light for seaweeds to grow here. Animals, living amongst the corals include: basket, brittle and feather starfish, bivalves (with their paired, hinged shells), shrimp-like animals and deep-water fish.

It is thought that, like most coral communities, coral gardens may be threatened by seabed trawling operations and smothering.

Cold-water corals were discovered in the 18th century, but we still know very little about them as most are found in deep water, too deep for divers to explore. Modern technology is helping us to discover more.

Brief description of European distribution

Coral gardens are present, to varying degrees, across most regions of the north-east Atlantic.

Further information sources

Coral reefsexternal link (JNCC)

Cold-water corals –what are they and where are they?external link (Royal Museums Greenwich)

Cold-water coral researchexternal link (SAMS)

Coral gardensexternal link (PDF) (OSPAR)

Interesting fact

Tropical corals are only found in shallow water because they have tiny plants living in their tissues, which need sunlight to survive. Deep, cold-water corals do not host these plants, so they can live in the permanent darkness of the deep sea.