The word coral conjures images of tropical waters with colourful reefs within snorkelling distance of the shore. These are tropical corals and are among the most studied and loved ecosystems on earth. It may surprise people to hear that corals aren't just found in the tropics. The cold, dark waters of the deep-ocean are home to cold-water coral reefs.

Since the early 1800s scientists have known about corals and coral banks in the deep-sea. Many reports came from fishermen who brought back coral specimens which had become entangled in their nets - capturing the attention of scientists with the promise of these tantalizing glimpses of a hidden coral world.

Since these pioneering days, deep-sea science has advanced significantly. The development of tools ranging from acoustic mapping systems to mini-submarines has allowed scientists to visit cold-water corals in their natural habitat. Scientists have now recorded over 1,300 species living among coral reefs in the north-eastern Atlantic, proving them to be among the most important and diverse ecosystems of the world.

Cold-water corals are widely distributed and found in many parts of the world's oceans. The Atlantic, Mediterranean, Indian and Pacific Oceans have all been found to contain cold-water corals. So far, many of the reports have been from the north-east Atlantic, where much of the current research has been undertaken.