A statement by the scientists was released simultaneously at a meeting of the UN Convention on Biological Diversity in the Malaysian capital Kuala Lumpur and at the annual meeting of the American Association for the Advancement of Science in the United States.

"Shallow-water coral reefs are sometimes called 'the rainforests of the sea' for their extraordinary biological diversity, perhaps the highest anywhere on Earth," the 1,136 scientists from 69 countries said.

"However, until quite recently, few people knew that the majority of coral species live in colder, darker depths, or that some of these form coral reefs and forests similar to those of shallow waters in appearance, species richness and importance to fisheries."

Some corals resemble "trees" up to 10 meters tall while others form dense thickets supporting hundreds or thousands of species.

But just as scientists have begun to understand their importance "human activities, particularly bottom trawling, are causing unprecedented damage", the statement said.

"Even before scientists can find them, deep-sea coral and sponge ecosystems are being destroyed by commercial fishing, especially bottom trawling."

Bottom trawling involves dragging heavy chains, nets and steel plates across the ocean floor.

The scientists, described as the world's foremost biologists, say it is not too late to save most of the world's deep-sea coral and sponge ecosystems.

They urged the United Nations and appropriate international bodies to establish a moratorium on bottom trawling on the high seas.

"Similarly, we urge individual nations and states to ban bottom trawling to protect deep-sea ecosystems wherever coral forests and reefs are known to occur within their Exclusive Economic Zones."

In recent years scientists have discovered deep-sea corals in Japan, Tasmania, New Zealand, Alaska, California, Nova Scotia, Maine, North Carolina, Florida, Colombia, Brazil, Norway, Sweden, the United Kingdom, Ireland and Mauritania.

"Because research submarines and remotely operated vehicles suitable for studying the deep sea are few and expensive to operate, scientific investigation of these remarkable communities is in its very early stages.

"Deep-sea corals and sponges may live for centuries, making them and the myriad species that depend on them extremely slow to recover from disturbance," with some threatened with extinction.

A recently-released study commissioned by the WWF, the World Conservation Union (IUCN) and the US-based Natural Resources Defence Council says fewer than 300 vessels are involved each year in deep-sea bottom trawling.

They make up a tiny fraction of the world's fishing fleet of three million, but their method "rapidly reduces ancient, thriving bottom complexes to rubble," the study says.

Fishing vessels flagged to only 13 countries, mainly from the developed world, took more than 95 percent of reported high seas bottom trawl catch in 2001, the last year for which data is available, the study shows.

TERRA.WIRE