The existence of cold-water corals has been known since the 18th Century, but the vast number of reefs found in the deeper reaches of the world's waters has amazed researchers. Yet just as scientists are beginning to understand the significance of the coral to the surrounding environment, they are also witnessing destruction.It is only in the past few decades that technology allowing humans to peer into the previously uncharted depths has become available to scientists. One of the most startling discoveries has been the number of coral reefs living hundreds of metres beneath the surface, in temperatures ranging from 4-13C (39-55F).

'Glacial' growth

Environmentalists point the finger of blame at the fishing industry and the practice of bottom-trawling with drag nets.This method of fishing involves scouring the sea bed with huge nets that are some 60m-wide; they are held apart by two huge metal plates weighing up to five tonnes.

It's heavy gear, and the reefs and the coral colonies are very fragile and easily damaged," Jan Helge Fossa, chief scientist at the Norwegian Institute of Marine Research, tells TVE's Earth Report programme for BBC World.

Cold corals are very slow growing. Some individuals are estimated to be up to 1,800 years old, and many reefs began forming at the end of the last Ice Age.
Damage inflicted by bottom-trawling can result in catastrophic consequences for the species living amid the reefs.

Climate change threatens supplies of water for millions of people in poorer countries, warns a new report from the Christian development agency Tearfund.
Recent research suggests that by 2050, five times as much land is likely to be under "extreme" drought as now.Tearfund wants richer states to look at helping poorer ones adjust to drought at next month's UN climate summit.Areas where people are already on the move to avoid climate excesses include, the report says:
Brazil, where one in five people born in the arid northeast region relocates to avoid drought
China, where three provinces are seeing the spread of the Gobi desert
Nigeria, where about 2,000 sq km is becoming desert each year
Attributing the movement of people to climate impacts is, however, a difficult issue, with many other factors including economic opportunity behind decisions to relocate