The proposal to ban commercial trade was put forward by Thailand, which is hosting this year's Cites conference.

In a separate development, Cites has imposed stricter trade laws for caviar and a cactus used in diet pills.

"The proposal by Thailand [to ban trade in the Irrawaddy dolphin] reflects the growing significance given to coastal conservation," said Robert Mather, from the WWF global conservation programme.

"We're encouraged by this development and believe that Thai communities will actually see a greater economic benefit from the development of ecotourism around Irrawaddy dolphins in the wild than from live trade."

No trade

The Cites decision places Irrawaddy dolphins on its so-called Appendix I, where it joins species like great apes and tigers, which are so endangered that no international commercial trade is allowed.

Irrawaddy dolphins are found in small, geographically isolated populations from Australia to India and the Philippines.

Their ability to live in both salt and fresh water makes them popular with dolphin shows, where fresh water tanks are cheaper to maintain. They are also easily trained and highly charismatic, making them popular attractions.

"Most legitimate zoos and aquariums already refuse to display Irrawaddy dolphins because of their endangered status," said Karen Steuer, a senior policy adviser to WWF. "But there remains an active trade in them for dolphin shows and water parks across Asia."

However, by far the biggest threat the dolphins face is drowning in fishing nets. The mammals live in shallow waters near shore or in rivers and suffer high death rates as bycatch in fishing nets.

According to the WWF, Irrawaddy dolphins in the Philippines are down to fewer than 70 individuals and will soon die out altogether if nothing is done about the bycatch problem.

Rare cactus

During the conference in Bangkok, Cites delegates are considering the status of a number of endangered species.

The watchdog agreed on Friday to include the rare hoodia cactus in Appendix II - which will regulate global trade in the plant - at the behest of South Africa, Namibia and Botswana.

The hoodia cactus is sought by drug companies because of its appetite-suppressing qualities.

The rare plant has been used for thousands of years by southern Africa's San Bushmen to dampen their appetites during long treks through the harsh Kalahari desert, and holds the key to potentially lucrative anti-obesity drugs.

South Africa's Council for Scientific and Industrial Research has patented the chemical entity extracted from hoodia and licensed British drugs-from-plants firm Phytopharm PLC to develop the plant's commercial potential.

Phytopharm said it welcomed moves to protect hoodia from illegal cultivation.

"We're very pleased it went through," said John Donaldson, of the South African delegation, adding it would help ensure that hoodia is used in a sustainable manner.

Cites delegates also decided to cut the 2004 Caspian Sea export quotas of caviar, which will drive up the price of the luxury food.

"The Caspian states have agreed to reduce substantially their caviar exports this year," Jim Armstrong, deputy secretary general of Cites, said on Friday.

Azerbaijan, Iran, Kazakhstan and Russia agreed to cut their combined 2004 Caspian caviar quotas from 146,210kg (322,300lb) in 2003 to 113,554kg (250,200lb).

Their combined export quota for caviar from beluga, the rarest and most valuable of all sturgeon, was slashed by 50% to 4,425kg (9,755lb).

The Caspian produces 90% of the world's supply of caviar, but years of poaching and pollution have ravaged stocks of the long-snouted boneless fish and forced lower quotas.

The Cites conference continues until 14 October. All decisions taken during the meeting need to be confirmed in a plenary session at the end of the 12-day summit.

http://news.bbc.co.uk/2/hi/science/nature/3726594.stm